Hindawi Publishing CorporationMathematical Problems in EngineeringVolume 2013 Article ID 404327 9 pageshttpdxdoiorg1011552013404327
Research ArticleSimulation of Multiphase Flow of the Oil-Water Separation ina Rotating Packed Bed for Oil Purification
Xiaojun Zhang Yun Cheng Songlin Nie Hui Ji and Laiguo Liu
College of Mechanical Engineering and Applied Electronics Technology Beijing University of Technology Beijing 100124 China
Correspondence should be addressed to Songlin Nie niesonglintomcom
Received 12 December 2012 Accepted 22 January 2013
Academic Editor Xiaosheng Qin
Copyright copy 2013 Xiaojun Zhang et alThis is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited
HIGEE (High Gravity Rotary Device) rotating oil purifier which consists of two parts hydrocyclone separator and rotating packedbed (abbr RPB) is considered to be capable of removing the solid particle contaminant moisture and gas simultaneously As themajor unit of HIGEE the RPB uses centrifugal force to intensifymass transfer Because of the special structure of RPB the hydrauliccharacteristics of the RPB are very important In this study the multiphase flow model in porous media of the RPB is presentedand the dynamical oil-water separation in the RPB is simulated using a commercial computational fluid dynamics code Theoperating conditions and configuration on the hydraulic performance of the RPB are investigated The results have indicated thatthe separation efficiency of HIGEE rotating oil purifier is predominantly affected by operating conditions and the configurationsThe best inlet pressure is 0002MPa When the liquid inlet is placed in the outside of the lower surface of RPB oil outlet is placedin the upper surface where it is near the rotation axis and water outlet is placed in the middle of the RPB where it is far away fromthe oil outlet the separating efficiency is the best
1 Introduction
The pollution of hydraulic engineering equipment is themainly responsible for the trouble of hydraulic system andit is the key of maintenance Contaminant particles canbring about a number of detrimental effects on the hydraulicsystem components as well as the fluid itself One of thekey problems of hydraulic contamination control is to designand maintain system reasonably reducing the contaminationlevel of key point as low as possible There are various kindsof purification technologies to improve the contaminationcontrol level of fluid power system (FPS) such as oil filterelectrostatic oil cleaner oil vacuum cleaning magnetic fieldpulse filtration and other coalescence methods [1] Howevermost of traditional purification technologies can only removeindividual contamination while there are solid particle con-taminant moisture and gas simultaneously in the FPS Anovel hydraulic oil purifier is developed to be capable ofremoving the solid particle contaminant moisture and gassimultaneously which consists of two parts hydrocycloneseparator and rotating packed bed (RPB) as shown inFigure 1
Rotating packed beds (RPBs) intensify mass transferby using centrifugal force to realize separation which hasbeen applied to distillation absorption striping polymerdevolatilization bio-oxidation and so on [2ndash6] HIGEE(high gravity rotary device) rotating oil purifier is basedon the traditional oil purification which is developed onthe introduction of the HIGEE technology The fluid frompreliminary purification goes into the internal space ofrotating bed along the axis of rotation and rotates at highspeed with the rotating packed bed driven by the motor Thefunction of packing is increasing the speed of fluid and hugeshear force overcomes surface forces increasing contact areabetween different phases tearing fluid into spray of micronorder In the action of HIGEE when the droplet containsspray through the voids of the layers of packing which rotatesat high speed which is bend narrow and varied whichis also filled with very thin spray and very small dropletthe inertia settlement ability of spray and droplet will beenhanced It will form rapid collision for effective coagulationbetween droplet and spray in the action of different physicalproperties of packing which are hydrophilic or hydrophobicto droplet and spray finally the media of different density
2 Mathematical Problems in Engineering
Figure 1 3D plot of HIGEE rotating oil purifier
are separated out in the action of centrifugal force[7]
The hydraulic characteristics of the RPB have beenreported in many studies such as the liquid holdup thepressure drop flooding residence time distribution andvisualized liquid flow [8ndash11] Ramshaw and Mallinson con-ducted a water-oxygen absorption system in an RPB andfound that the mass transfer coefficient was 27ndash44 timeshigher than that in conventional packed columns [12] Tungand Mah theoretically proposed a correlation for the masstransfer coefficient in an RPB [13] Munjal et al proposeda correlation in an RPB theoretically and experimentallystudied for the absorption ofCO
2fromair intoNaOH [14 15]
Kumar and Gardner obtained mass transfer coefficients in anRPB packed with aluminum foam metal of various specificsurface areas in a CO
2-water system [16] In 1990 Kumar
and Rao performed experiments of absorption of CO2from
air into NaOH solution in an RPB and found that the masstransfer coefficient changed with increasing liquid rates androtation speeds [17] Singh et al investigated themass transferin an RPB for air stripping of volatile organic compoundsfrom groundwater [18] Chen et al also did a lot of researchon the RPB they evaluated the mass transfer coefficient of anoxygen-water absorption system [19] and they investigatedthe influence of liquid viscosity on the mass transfer ratefor both Newtonian and non-Newtonian fluids in an RPB[20] Further they evaluated the end effects of an RPB byvarying the radii of the packed bed [21] Burns and Ramshawtook the visual study of liquid flow in RPBs under differentrotating speedsThey observed the spiral of liquid and severeliquid maldistribution on radial orientation in contrast theliquid wandered slightly laterally and consequently led to arelatively uniform distribution on the tangential orientation
9
8
7
6 5
4
3
21
Rotating packed bedHydrocyclone separator
Figure 2 Sectional drawing of HIGEE rotating oil purifier 1connecting motor shaft 2 the hydraulic oil outlet 3 packing 4vortex finder 5 underflow outlet 6 shell 7 tangential nozzle 8contaminated oil inlet 9 parting face
[22] Similar results were reached by the researchers [7] inBeijing University of Chemical Technology [11]
Many studies have been investigated by theory or exp-eriment However many physical experiments are veryexpensive and time-consuming and there are no preciseexperimental data about the flow in RPBs Hence usingmathematical models as design tools can contribute to abetter understand of the hydraulic characteristics of theRPB with the fast development of the computer technologyComputational fluid dynamics (CFD) is a good design andanalysis tool to simulate the flow of mass and momentumthroughout a fluid continuum It is an advantage methodto study the hydraulics characteristics of RPB Numericalsimulation by using FLUENT software will be conductedin this research The multiphase flow in porous media ofRPB will be numerically studied The effects of operatingconditions and configuration on the hydraulic performanceof RPB are investigated to increase the separation efficiencyof HIGEE rotating oil purifier
2 Mathematical Methods
21 Physical Model According to the introduction of HIGEErotating oil purifier (Figure 1) Figure 2 shows the geometricaldiagram of HIGEE rotating oil purifier designed for thisresearch which consists of two parts hydrocyclone separatorand rotating packed bed (RPB)The hydraulic characteristicsof RPB are very important In this study the multiphase flowmodel in porous media of RPB is presented
The 3D model (Figure 3) is developed for the RPBconsidered using a commercial code Gambit The diameterof the RPB is 110mm and its height is 60mm The wholerotating packed bed is taken as the object of study in thisresearch In Figure 3 the whole rotating packed bed is acylinder There are three small cylinders at the upper andlower surfaces of the RPBThe oil and water outlets are at theupper surface and the oil-water mixture inlet is at the lowersurface
Mathematical Problems in Engineering 3
Figure 3 3D model of the RPB
22 Mathematical Model In this research the Eulerian mul-tiphase model is applied The phases are water and oil Thedescription of multiphase flow as interpenetrating continuaincorporates the concept of phasic volume fractions which isdefined by 120572
119902in this paper Because there is no temperature
gradient so only the mass conservation and the momentumequations are used Volume fractions represent the spaceoccupied by each phase and the laws of conservation of massand momentum are satisfied by each phase individually [23]
The volume of phase 119902 is 119881119902 which is defined by
119881119902= int
119881
120572119902119889119881 (1)
where119899
sum
119902=1
120572119902= 1 (2)
The effective density of phase 119902 is
120588119902= 120572119902120588119902 (3)
where 120588119902is the physical density of phase 119902 Continuity
equation is shown as
nabla sdot (120588119902120584) = 0 (4)
where 120584 is the vector velocity of the liquid Momentumbalance equation is shown as
nabla sdot (120588119902120584120584) = minusnabla times 119875 + nabla sdot (120583 (nabla times 120584 + (nabla times 120584)
119879)) (5)
where 119875 is the static pressure and 120583 is the viscosity Porousmedia are simulated by adding a momentum source term 119878
119894
to the standard fluid flow equations therefore themomentumbalance in the porous media could be defined as
nabla sdot (120588119902120584120584) = minusnabla times 119875 + nabla sdot (120583 (nabla times 120584 + (nabla times 120584)
119879)) + 119878
119894
(119894 = 119909 119910 119911)
(6)
where 119878119894is the source term for the momentum equation
which is composed of two parts a viscous loss term (the first
Figure 4 Mesh generation of the 3D model
term on the right-hand side of (7)) and inertial loss term (thesecond term on the right-hand side of (7))
where 119863 and 119862 are viscous resistance and inertia losscoefficient matrices respectively When the case is simplehomogeneous porous media the source term is shown as
where 120572 is the permeability and 1198622is the inertial resistance
coefficient119863 and119862 are simply specified as diagonal matriceswith 1120572 and 119862
2 respectively [24 25]
In this paper the Ergun equation is used to deriveporous media input for a packed bed and the laminar flowthrough the porous media is simulated which is similar toa packed bed in this paper and easy to simulate on existingcomputers The permeability and inertial loss coefficients ineach component direction could be identified as
120572 =
1198892
150
1205763
(1 minus 120576)2
1198622=
35
119889
(1 minus 120576)
1205763
(9)
where 119889 is the mean particle diameter and 120576 is the voidfraction [26]
23 Grid Generation and Boundary Condition To solve thegoverning equations appropriate grid generation and bound-ary conditions are specified at all external boundaries basedon the following The 3D model (Figure 3) is meshed intotetrahedral grid (Figure 4) which has about 920538 elementsand 164675 nodes for the 3D computational grid The meshdensity is increased appropriately to improve the computa-tional convergent velocity The technique of finite volume isselected to solve the governing equations Frequently suitablevalues of the underrelaxation factors are adopted to assurethe smooth convergence of the numerical solution In the
Figure 5 Contours of the outlet volume fraction of oil in the outlet with different pressures
Table 1 Material properties of the model
Parameter Unit Water OilVolume fraction mdash 5 95Density kgm3 1000 780Viscosity kgms 0001003 00024
oil-water two-phase flow the material properties [27] andboundary conditions [28 29] in this research can be seen inTables 1 and 2
The material properties and boundary conditions areselected reasonably The standard 119870-120576 model is selectedwhere robustness economy and reasonable accuracy fora wide range of turbulent flows explain its popularity inindustrial flow and heat transfer simulations
3 Results and Discussion
The multiphase flow in porous media of RPB will be nu-merical simulated The effects of operating conditions andconfiguration on the hydraulic performance of the RPB areinvestigated to increase the separation efficiency of HIGEErotating oil purifier
31 Effect of the Inlet Pressure To understand the featuredistribution of inner hydrocyclone separatormore clearly theoutlet pressure of hydrocyclone separator is 0002MPawhichis considered a reference The static pressure is firstly to be
Table 2 Boundary conditions of the model
Description TypePorosity of porous medium 05Mean particle diameter of porous medium 005mmFlow condition of the oil-water mixture TurbulenceViscous model 119870-120576modelInlet of the oil-water mixture Pressure inletOutlet of oil or water Pressure inlet
simulated as shownThis example is identified as follows theconfiguration of the RPB is certain The oil-water mixtureinlet is set near to the middle of the lower surface of the RPBwhose diameter is 15mm The outlet for water and oil is setin the upper surface where the oil outlet is in the middlewhile the water outlet is in the edge The diameter of outletsis 10mm The rotation speed is 1500 rpm The other condi-tions are constant This research investigated the separationefficiency of HIGEE rotating oil purifier by changing the inletpressure The sectional drawings are extracted Contour plotand graph of the outlet volume fraction of oil in the outletwith different pressures are shown in Figures 5 and 6
Figure 5 displays contour plots of the outlet volumefraction of oil in the outlet with different pressures Asshown in Figure 5(a) the liquid inlet pressure is 001MPaThe volume fraction of oil in the oil outlet is not entirely100 and the fraction of oil in the water outlet can be about96 In Figure 5(b) the liquid inlet pressure is 0005MPa
Mathematical Problems in Engineering 5
1119890+00
98119890minus01
96119890minus01
94119890minus01
92119890minus01
9119890minus01
88119890minus01
86119890minus01
Volu
me f
ract
ion
(ker
osen
e)
001 002 003 004 005 006 007 008Position (m)
Oil outletWater outlet
(a) 001MPa
1119890+00
8119890minus01
98119890minus01
96119890minus01
94119890minus01
92119890minus01
9119890minus01
88119890minus01
86119890minus01
Volu
me f
ract
ion
(ker
osen
e)
001 002 003 004 005 006 007 008Position (m)
Oil outletWater outlet
84119890minus01
82119890minus01
(b) 0005MPa
1119890+00
98119890minus01
96119890minus01
94119890minus01
92119890minus01
9119890minus01
88119890minus01
86119890minus01
Volu
me f
ract
ion
(ker
osen
e)
001 002 003 004 005 006 007 008Position (m)
Oil outletWater outlet
(c) 0002MPa
1119890+00
98119890minus01
96119890minus01
94119890minus01
92119890minus01
9119890minus01
88119890minus01
86119890minus01
84119890minus01
82119890minus01
Volu
me f
ract
ion
(ker
osen
e)
001 002 003 004 005 006 007 008Position (m)
Oil outletWater outlet
(d) 0001MPa
Figure 6 Graphs of the outlet volume fraction of oil in the outlet with different pressures
The volume fraction of oil in the oil outlet can be up to 100and the fraction of oil in the water outlet can also be about99 However when the liquid inlet pressure is 0002MPathe volume fraction of oil in the oil outlet can be up to 100as seen in Figure 5(c) and the fraction of oil in the wateroutlet can also be about 96 When the liquid inlet pressureis 0001MPa the volume fraction of oil in the oil outlet can beup to 100 which is shown in Figure 5(d) and the fractionof oil in the water outlet can also be about 98
Figure 6 displays graphs of the outlet volume fraction ofoil in the outlet with different pressures The volume fractionof oil in the oil outlet can be up to 100 but it is not entirely100 as shown in Figure 6(a) and the fraction of oil in thewater outlet can also be about 96 In Figure 6(b) the volumefraction of oil in the oil outlet can be up to 100 and it is
entirely 100 but the fraction of oil in the water outlet canalso be about more than 99 When the liquid inlet pressureis 0002MPa the volume fraction of oil in the oil outlet canbe up to 100 as shown in Figure 6(c) and it is entirely 100but the fraction of oil in the water outlet can also be about lessthan 96 As shown in Figure 6(d) the volume fraction of oilin the oil outlet can be up to 100 and it is entirely 100 butthe fraction of oil in the water outlet can also be about morethan 98
It can be seen from the simulation results that the inletpressure has a big effect on the separation efficiency ofHIGEErotating oil purifier The separation efficiency of HIGEErotating oil purifier improves with the decreasing of inletpressure in particular when the inlet pressure is 0002MPathe separation efficiency is the best The volume fraction of
6 Mathematical Problems in Engineering
1119890+00
966119890minus01
932119890minus01
898119890minus01
864119890minus01
83119890minus01
796119890minus01
762119890minus01
729119890minus01
695119890minus01
661119890minus01
119885
119883 119884
(a) Configuration A
1119890+00
967119890minus01
935119890minus01
902119890minus01
87119890minus01
837119890minus01
804119890minus01
772119890minus01
739119890minus01
707119890minus01
674119890minus01
119885
119883 119884
(b) Configuration B
119885
119883 119884
1119890+00
982119890minus01
963119890minus01
945119890minus01
926119890minus01
908119890minus01
889119890minus01
871119890minus01
853119890minus01
834119890minus01
816119890minus01
(c) Configuration C
1119890+00
98119890minus01
96119890minus01
941119890minus01
921119890minus01
901119890minus01
881119890minus01
861119890minus01
842119890minus01
822119890minus01
802119890minus01
119885
119883 119884
(d) Configuration D
Figure 7 Contours of the volume fraction of oil in the outlet with different configurations
oil in the oil outlet can be up to 100 and it is entirely 100and the fraction of oil in the water outlet can also be aboutless than 96 which is better than other inlet pressures
32 Effect of the Configuration In order to investigate theeffect of the configuration the example is identified asfollows The rotation speed is 1500 rpm The inlet pressure is0002MPa with the other boundary conditions unchangedThis research investigated the separation effect of HIGEErotating oil purifier by changing the configuration such as thelocation of the oil-water mixture inlet oil outlet and wateroutlet in the RPB
Based on previous theoretical and experimental resultsfluids of different densitieswill concentrate ondifferent placesaccordingly under rotation speed The fluid of high densityconcentrates close to the rotation axis while the fluid of lowdensity concentrates away from the rotation axis Thereforefour different configurations are investigated in this researchConfiguration A The oil-water mixture inlet is placed inthe middle of the lower surface of RPB whose diameteris 15mm the water outlet is placed in the outside of thelower surface whose diameter is 5mm and the oil outlet isplaced in the middle of the upper surface whose diameteris 20mm Configuration B The water outlet is also placedin the outside of the lower surface but its width is 25mmwhich is different fromConfigurationAConfigurationCTheoil-water mixture inlet is placed in the outside of the lowersurface whose width is 75mm the water outlet is placedin the side of upper whose diameter is 5mm and the oiloutlet is placed in the middle of the upper face whose widthis 10mm Configuration D The water outlet is placed in the
side of middle which is different from Configuration C Thesectional drawings are extracted Contour plot and graph ofthe outlet volume fraction of oil in the outlet with differentconfigurations are shown in Figures 7 and 8
Figure 7 displays contour plots of the outlet volumefraction of oil in the outlet with different configurations Asshown in Figure 7(a) the volume fraction of oil in the oiloutlet can be up to 100 and the fraction of oil in the wateroutlet can also be about 95 In Figure 7(b) the volumefraction of oil in the oil outlet can be up to 100 and thefraction of oil in the water outlet can also be about morethan 98 Corresponding to the ConfigurationC the volumefraction of oil in the oil outlet can be up to 100 and thefraction of oil in the water outlet can also be about more than95 (Figure 7(c)) The volume fraction of oil in the oil outletcan be up to 100 which is shown in Figure 7(d) and thefraction of oil in the water outlet can also be about less than95
Figure 8 displays graphs of the outlet volume fraction ofoil in the outlet with different configurations The volumefraction of oil in the oil outlet can be up to 100 but it isnot entirely 100 which is shown in Figure 8(a) And thefraction of oil in the water outlet can also be about 95 InFigure 8(b) the volume fraction of oil in the oil outlet can beup to 100 and it is entirely 100 but the fraction of oil in thewater outlet can also be aboutmore than 98Correspondingto Configuration C the volume fraction of oil in the oil outletcan be up to 100 and it is entirely 100 but the fractionof oil in the water outlet can also be about more than 95(Figure 8(c)) As shown in Figure 8(d) the volume fractionof oil in the oil outlet can be up to 100 and it is entirely
Figure 8 Graphs of the volume fraction of oil in the outlet with different configurations
100 but the fraction of oil in the water outlet can also beabout less than 95
Simulation results show that the simulation results indi-cate that the separating efficiency of HIGEE rotating oilpurifier is greatly affected by the configuration ConfigurationD is the best configuration In Configuration D the volumefraction of oil in the oil outlet can be up to 100 and it isentirely 100 but the fraction of oil in the water outlet canalso be about less than 95
33 Discussion Simulation results show that because of dif-ferent densities when the oil from preliminary purificationgoes through the HIGEE field the oil-which has a low
density outflows from the oil outlet in the middle where it isnear the rotation axis while water which has a high densityoutflows from the water outlet is in the edge where it is faraway from the oil outlet
Applying the inlet pressure is for applying an inlet velocityto the oil from preliminary purification When the inletpressure is small which can increase the residence time ofthe oil-water mixture therefore the fluid from preliminarypurification can make a good contact with hydrophilicmaterial in the RPB to get better separation efficiency Theseparation efficiency of HIGEE rotating oil purifier increaseswith the decreasing of inlet pressure in particular when theinlet pressure is 0002MPa the separation efficiency is thebest However a small pressure is not the best choice for the
8 Mathematical Problems in Engineering
inlet pressureTheworking hours will last long when the inletvelocity is very small
The separating efficiency of HIGEE rotating oil purifier isgreatly affected by the configurations Configuration D is thebest configuration The layout of liquid inlet oil outlet andwater outlet of the RPB significantly affected the separatingefficiencyWhen the liquid inlet is placed in the outside of thelower surface of RPB oil outlet is placed in the upper surfacewhere it is near the rotation axis and water outlet is placedin the middle of the side of the RPB where it is far awayfrom the oil outlet the corresponding separating efficiencywas the best In Configuration D the volume fraction of oil inthe oil outlet can be up to 100 and it is entirely 100 butthe fraction of oil in the water outlet can also be about lessthan 95 which is better than other configurations
4 Conclusions
Unlike previous experimental research numerical simulationis employed in this paper to analyze the flow characteristicsinside the RPB and related conclusions are got
(1) The oil-water two-phase flow is simulated based onthe 3D model of the RPB which is established inGambit
(2) The operating conditions on the hydraulic perfor-mance of the RPB are investigated Inlet pressure hasbig effect on the separation efficiency of HIGEE rotat-ing oil purifier The separation efficiency of HIGEErotating oil purifier increases with the decreasing ofinlet pressure in particular when the inlet pressure is0002MPa the separation efficiency is the best
(3) Simulation results also show that the separatingefficiency of HIGEE rotating oil purifier is greatlyaffected by the configuration especially the layout ofliquid inlet oil outlet and water outlet in the RPBWhen the liquid inlet is placed in the outside of thelower surface of RPB oil outlet is placed in the uppersurface where it is near to the rotation axis andwater outlet is placed in the middle of the side ofthe RPB which it is far away from the oil outlet thecorresponding separating efficiency is the best
Compared with theoretical analysis and experimentalresearch numerical simulation has provided an easy andeffective method to design and optimize the HIGEE rotatingoil purifier and other mechanical devices which was widelyused in resources and environmental systems In order tocertificate the numerical results corresponding experimentsneed to be investigated in the future work
Acknowledgments
This research was funded by the Natural Science Founda-tions of China (no 51075007) National High-tech RampD(863) Program (no 2012AA091103) and The Importationand Development of High-Caliber Talents Project of BeijingMunicipal Institutions (CITampTCD 20130316)
References
[1] Z X Xia Contamination Control of Hydraulic System ChinaMachine Press Beijing 1992
[2] C Ramshaw ldquolsquoHiGeersquo distillation-An example of process inten-sificationrdquo Chemical Engineering Science vol 389 pp 13ndash141983
[3] M Keyvani and N C Gardner ldquoOperating characteristics ofrotating bedsrdquo Chemical Engineering Progress vol 85 no 9 pp48ndash52 1989
[4] H S Liu C C Lin S C Wu and H W Hsu ldquoCharacteristicsof a rotating packed bedrdquo Industrial and Engineering ChemistryResearch vol 35 no 10 pp 3590ndash3596 1996
[5] D P RaoA Bhowal andP SGoswami ldquoProcess intensificationin rotating packed beds (HIGee) an Appraisalrdquo Industrial andEngineering Chemistry Research vol 43 no 4 pp 1150ndash11622004
[6] X Li Y Liu Z Li and X Wang ldquoContinues distillation exper-iment with rotating packed bedrdquo Chinese Journal of ChemicalEngineering vol 16 no 4 pp 656ndash662 2008
[7] H Ji S L Nie H M Sun and X H Tang ldquoResearch on on-linepurification of hydraulic oil based on high gravity technologyrdquoChinese Hydraulics amp Pneumatics no 11 pp 1ndash6 2011
[8] C Zheng K Guo Y Feng C Yang and N C GardnerldquoPressure drop of centripetal gas flow through rotating bedsrdquoIndustrial and Engineering Chemistry Research vol 39 no 3 pp829ndash834 2000
[9] A Basic and M P Dudukovic ldquoLiquid holdup in rotatingpacked beds examination of the film flow assumptionrdquo AIChEJournal vol 41 no 2 pp 301ndash316 1995
[10] M J Lockett ldquoFlooding of rotating structured packing and itsapplication to conventional packed columnsrdquo Trans IChemEvol 73 pp 379ndash384 1995
[11] K Guo F Guo Y Feng J Chen C Zheng and N C GardnerldquoSynchronous visual and RTD study on liquid flow in rotatingpacked-bed contractorrdquo Chemical Engineering Science vol 55no 9 pp 1699ndash1706 2000
[12] C Ramshaw and R H Mallinson ldquoMass transfer processrdquo USPatent 4 vol 283 no 255 1981
[13] H H Tung and R S H Mah ldquoModeling liquid mass tranferin HIGee separtion processrdquo Chemical Engineering Communi-cations vol 39 no 1ndash6 pp 147ndash153 1985
[14] S Munjal M P Dudukovc and P Ramachandran ldquoMass-transfer in rotating packed beds-I Development of gas-liquidand liquid-solidmass-transfer correlationsrdquoChemical Engineer-ing Science vol 44 no 10 pp 2245ndash2256 1989
[15] S Munjal M P Dudukovic and P Ramachandran ldquoMass-transfer in rotating packed beds-II Experimental results andcomparisonwith theory and gravity flowrdquoChemical EngineeringScience vol 44 no 10 pp 2257ndash2268 1989
[16] M Kumar and N C Gardner ldquoOperating characteristics ofrotating bedsrdquo Chemical Engineering Science vol 85 no 9 pp48ndash52 1989
[17] M P Kumar andD P Rao ldquoStudies on a high-gravity gas-liquidcontactorrdquo Industrial Engineering Chemistry Research vol 29no 5 pp 917ndash920 1990
[18] S P Singh J H Wilson R M Counce et al ldquoRemoval ofvolatile organic compounds from groundwater using a rotaryair stripperrdquo Industrial and Engineering Chemistry Research vol31 no 2 pp 574ndash580 1992
Mathematical Problems in Engineering 9
[19] Y H Chen C Y Chang W L Su et al ldquoModeling ozonecontacting process in a rotating packed bedrdquo Industrial andEngineering Chemistry Research vol 43 no 1 pp 228ndash2362004
[20] Y S Chen C C Lin and H S Liu ldquoMass tranfer in a rotationgpacked bed with viscous newtonian and non-newtonian fluidsrdquoIndustrial Engineering Chemistry Research vol 44 no 4 pp1043ndash1051 2005
[21] Y S Chen C C Lin and H S Liu ldquoMass tranfer in a rotationgpacked bed with viscous radii of the bedrdquo Industrial EngineeringChemistry Research vol 44 no 20 pp 7868ndash7875 2005
[22] J R Burns and C Ramshaw ldquoProcess intensification visualstudy of liquid maldistribution in rotating packed bedsrdquo Chem-ical Engineering Science vol 51 no 8 pp 1347ndash1352 1996
[23] L J Guo Two-Phase and multiPhase Hydrodynamics XirsquoanJiaotong University Press Xirsquoan China 2002
[24] X Y Kong Advanced Mechanics of Fluid Flow in Porous MediaChinese Science andTechnologyUniversity PressHefei China2010
[25] L S ChengAdvancedMechanics of Fluid Flow in PorousMediaPetroleum Industry Press Beijng China 2010
[26] L Fan RTHaiW XWang Z Lu andZM Yang ldquoApplicationof computational fluid dynamic to model the hydraulic perfor-mance of subsurface flow wetlandsrdquo Journal of EnvironmentalSciences vol 20 no 12 pp 1415ndash1422 2008
[27] Z Wen L C Shi and Y R Ren The Flent ComputationalDynamics Application Guide Tsinghua University Press Bei-jing China 2009
[28] J C Sheng Hydraulic Fluid Mechanics Mechanical IndustryPress Beijing China 1980
[29] Y Yu J M Zhang and L T Jiang Fluent Introductory andAdvanced Course Beijing Institute of Technology Press BeijingChina 2011
are separated out in the action of centrifugal force[7]
The hydraulic characteristics of the RPB have beenreported in many studies such as the liquid holdup thepressure drop flooding residence time distribution andvisualized liquid flow [8ndash11] Ramshaw and Mallinson con-ducted a water-oxygen absorption system in an RPB andfound that the mass transfer coefficient was 27ndash44 timeshigher than that in conventional packed columns [12] Tungand Mah theoretically proposed a correlation for the masstransfer coefficient in an RPB [13] Munjal et al proposeda correlation in an RPB theoretically and experimentallystudied for the absorption ofCO
2fromair intoNaOH [14 15]
Kumar and Gardner obtained mass transfer coefficients in anRPB packed with aluminum foam metal of various specificsurface areas in a CO
2-water system [16] In 1990 Kumar
and Rao performed experiments of absorption of CO2from
air into NaOH solution in an RPB and found that the masstransfer coefficient changed with increasing liquid rates androtation speeds [17] Singh et al investigated themass transferin an RPB for air stripping of volatile organic compoundsfrom groundwater [18] Chen et al also did a lot of researchon the RPB they evaluated the mass transfer coefficient of anoxygen-water absorption system [19] and they investigatedthe influence of liquid viscosity on the mass transfer ratefor both Newtonian and non-Newtonian fluids in an RPB[20] Further they evaluated the end effects of an RPB byvarying the radii of the packed bed [21] Burns and Ramshawtook the visual study of liquid flow in RPBs under differentrotating speedsThey observed the spiral of liquid and severeliquid maldistribution on radial orientation in contrast theliquid wandered slightly laterally and consequently led to arelatively uniform distribution on the tangential orientation
9
8
7
6 5
4
3
21
Rotating packed bedHydrocyclone separator
Figure 2 Sectional drawing of HIGEE rotating oil purifier 1connecting motor shaft 2 the hydraulic oil outlet 3 packing 4vortex finder 5 underflow outlet 6 shell 7 tangential nozzle 8contaminated oil inlet 9 parting face
[22] Similar results were reached by the researchers [7] inBeijing University of Chemical Technology [11]
Many studies have been investigated by theory or exp-eriment However many physical experiments are veryexpensive and time-consuming and there are no preciseexperimental data about the flow in RPBs Hence usingmathematical models as design tools can contribute to abetter understand of the hydraulic characteristics of theRPB with the fast development of the computer technologyComputational fluid dynamics (CFD) is a good design andanalysis tool to simulate the flow of mass and momentumthroughout a fluid continuum It is an advantage methodto study the hydraulics characteristics of RPB Numericalsimulation by using FLUENT software will be conductedin this research The multiphase flow in porous media ofRPB will be numerically studied The effects of operatingconditions and configuration on the hydraulic performanceof RPB are investigated to increase the separation efficiencyof HIGEE rotating oil purifier
2 Mathematical Methods
21 Physical Model According to the introduction of HIGEErotating oil purifier (Figure 1) Figure 2 shows the geometricaldiagram of HIGEE rotating oil purifier designed for thisresearch which consists of two parts hydrocyclone separatorand rotating packed bed (RPB)The hydraulic characteristicsof RPB are very important In this study the multiphase flowmodel in porous media of RPB is presented
The 3D model (Figure 3) is developed for the RPBconsidered using a commercial code Gambit The diameterof the RPB is 110mm and its height is 60mm The wholerotating packed bed is taken as the object of study in thisresearch In Figure 3 the whole rotating packed bed is acylinder There are three small cylinders at the upper andlower surfaces of the RPBThe oil and water outlets are at theupper surface and the oil-water mixture inlet is at the lowersurface
Mathematical Problems in Engineering 3
Figure 3 3D model of the RPB
22 Mathematical Model In this research the Eulerian mul-tiphase model is applied The phases are water and oil Thedescription of multiphase flow as interpenetrating continuaincorporates the concept of phasic volume fractions which isdefined by 120572
119902in this paper Because there is no temperature
gradient so only the mass conservation and the momentumequations are used Volume fractions represent the spaceoccupied by each phase and the laws of conservation of massand momentum are satisfied by each phase individually [23]
The volume of phase 119902 is 119881119902 which is defined by
119881119902= int
119881
120572119902119889119881 (1)
where119899
sum
119902=1
120572119902= 1 (2)
The effective density of phase 119902 is
120588119902= 120572119902120588119902 (3)
where 120588119902is the physical density of phase 119902 Continuity
equation is shown as
nabla sdot (120588119902120584) = 0 (4)
where 120584 is the vector velocity of the liquid Momentumbalance equation is shown as
nabla sdot (120588119902120584120584) = minusnabla times 119875 + nabla sdot (120583 (nabla times 120584 + (nabla times 120584)
119879)) (5)
where 119875 is the static pressure and 120583 is the viscosity Porousmedia are simulated by adding a momentum source term 119878
119894
to the standard fluid flow equations therefore themomentumbalance in the porous media could be defined as
nabla sdot (120588119902120584120584) = minusnabla times 119875 + nabla sdot (120583 (nabla times 120584 + (nabla times 120584)
119879)) + 119878
119894
(119894 = 119909 119910 119911)
(6)
where 119878119894is the source term for the momentum equation
which is composed of two parts a viscous loss term (the first
Figure 4 Mesh generation of the 3D model
term on the right-hand side of (7)) and inertial loss term (thesecond term on the right-hand side of (7))
where 119863 and 119862 are viscous resistance and inertia losscoefficient matrices respectively When the case is simplehomogeneous porous media the source term is shown as
where 120572 is the permeability and 1198622is the inertial resistance
coefficient119863 and119862 are simply specified as diagonal matriceswith 1120572 and 119862
2 respectively [24 25]
In this paper the Ergun equation is used to deriveporous media input for a packed bed and the laminar flowthrough the porous media is simulated which is similar toa packed bed in this paper and easy to simulate on existingcomputers The permeability and inertial loss coefficients ineach component direction could be identified as
120572 =
1198892
150
1205763
(1 minus 120576)2
1198622=
35
119889
(1 minus 120576)
1205763
(9)
where 119889 is the mean particle diameter and 120576 is the voidfraction [26]
23 Grid Generation and Boundary Condition To solve thegoverning equations appropriate grid generation and bound-ary conditions are specified at all external boundaries basedon the following The 3D model (Figure 3) is meshed intotetrahedral grid (Figure 4) which has about 920538 elementsand 164675 nodes for the 3D computational grid The meshdensity is increased appropriately to improve the computa-tional convergent velocity The technique of finite volume isselected to solve the governing equations Frequently suitablevalues of the underrelaxation factors are adopted to assurethe smooth convergence of the numerical solution In the
Figure 5 Contours of the outlet volume fraction of oil in the outlet with different pressures
Table 1 Material properties of the model
Parameter Unit Water OilVolume fraction mdash 5 95Density kgm3 1000 780Viscosity kgms 0001003 00024
oil-water two-phase flow the material properties [27] andboundary conditions [28 29] in this research can be seen inTables 1 and 2
The material properties and boundary conditions areselected reasonably The standard 119870-120576 model is selectedwhere robustness economy and reasonable accuracy fora wide range of turbulent flows explain its popularity inindustrial flow and heat transfer simulations
3 Results and Discussion
The multiphase flow in porous media of RPB will be nu-merical simulated The effects of operating conditions andconfiguration on the hydraulic performance of the RPB areinvestigated to increase the separation efficiency of HIGEErotating oil purifier
31 Effect of the Inlet Pressure To understand the featuredistribution of inner hydrocyclone separatormore clearly theoutlet pressure of hydrocyclone separator is 0002MPawhichis considered a reference The static pressure is firstly to be
Table 2 Boundary conditions of the model
Description TypePorosity of porous medium 05Mean particle diameter of porous medium 005mmFlow condition of the oil-water mixture TurbulenceViscous model 119870-120576modelInlet of the oil-water mixture Pressure inletOutlet of oil or water Pressure inlet
simulated as shownThis example is identified as follows theconfiguration of the RPB is certain The oil-water mixtureinlet is set near to the middle of the lower surface of the RPBwhose diameter is 15mm The outlet for water and oil is setin the upper surface where the oil outlet is in the middlewhile the water outlet is in the edge The diameter of outletsis 10mm The rotation speed is 1500 rpm The other condi-tions are constant This research investigated the separationefficiency of HIGEE rotating oil purifier by changing the inletpressure The sectional drawings are extracted Contour plotand graph of the outlet volume fraction of oil in the outletwith different pressures are shown in Figures 5 and 6
Figure 5 displays contour plots of the outlet volumefraction of oil in the outlet with different pressures Asshown in Figure 5(a) the liquid inlet pressure is 001MPaThe volume fraction of oil in the oil outlet is not entirely100 and the fraction of oil in the water outlet can be about96 In Figure 5(b) the liquid inlet pressure is 0005MPa
Mathematical Problems in Engineering 5
1119890+00
98119890minus01
96119890minus01
94119890minus01
92119890minus01
9119890minus01
88119890minus01
86119890minus01
Volu
me f
ract
ion
(ker
osen
e)
001 002 003 004 005 006 007 008Position (m)
Oil outletWater outlet
(a) 001MPa
1119890+00
8119890minus01
98119890minus01
96119890minus01
94119890minus01
92119890minus01
9119890minus01
88119890minus01
86119890minus01
Volu
me f
ract
ion
(ker
osen
e)
001 002 003 004 005 006 007 008Position (m)
Oil outletWater outlet
84119890minus01
82119890minus01
(b) 0005MPa
1119890+00
98119890minus01
96119890minus01
94119890minus01
92119890minus01
9119890minus01
88119890minus01
86119890minus01
Volu
me f
ract
ion
(ker
osen
e)
001 002 003 004 005 006 007 008Position (m)
Oil outletWater outlet
(c) 0002MPa
1119890+00
98119890minus01
96119890minus01
94119890minus01
92119890minus01
9119890minus01
88119890minus01
86119890minus01
84119890minus01
82119890minus01
Volu
me f
ract
ion
(ker
osen
e)
001 002 003 004 005 006 007 008Position (m)
Oil outletWater outlet
(d) 0001MPa
Figure 6 Graphs of the outlet volume fraction of oil in the outlet with different pressures
The volume fraction of oil in the oil outlet can be up to 100and the fraction of oil in the water outlet can also be about99 However when the liquid inlet pressure is 0002MPathe volume fraction of oil in the oil outlet can be up to 100as seen in Figure 5(c) and the fraction of oil in the wateroutlet can also be about 96 When the liquid inlet pressureis 0001MPa the volume fraction of oil in the oil outlet can beup to 100 which is shown in Figure 5(d) and the fractionof oil in the water outlet can also be about 98
Figure 6 displays graphs of the outlet volume fraction ofoil in the outlet with different pressures The volume fractionof oil in the oil outlet can be up to 100 but it is not entirely100 as shown in Figure 6(a) and the fraction of oil in thewater outlet can also be about 96 In Figure 6(b) the volumefraction of oil in the oil outlet can be up to 100 and it is
entirely 100 but the fraction of oil in the water outlet canalso be about more than 99 When the liquid inlet pressureis 0002MPa the volume fraction of oil in the oil outlet canbe up to 100 as shown in Figure 6(c) and it is entirely 100but the fraction of oil in the water outlet can also be about lessthan 96 As shown in Figure 6(d) the volume fraction of oilin the oil outlet can be up to 100 and it is entirely 100 butthe fraction of oil in the water outlet can also be about morethan 98
It can be seen from the simulation results that the inletpressure has a big effect on the separation efficiency ofHIGEErotating oil purifier The separation efficiency of HIGEErotating oil purifier improves with the decreasing of inletpressure in particular when the inlet pressure is 0002MPathe separation efficiency is the best The volume fraction of
6 Mathematical Problems in Engineering
1119890+00
966119890minus01
932119890minus01
898119890minus01
864119890minus01
83119890minus01
796119890minus01
762119890minus01
729119890minus01
695119890minus01
661119890minus01
119885
119883 119884
(a) Configuration A
1119890+00
967119890minus01
935119890minus01
902119890minus01
87119890minus01
837119890minus01
804119890minus01
772119890minus01
739119890minus01
707119890minus01
674119890minus01
119885
119883 119884
(b) Configuration B
119885
119883 119884
1119890+00
982119890minus01
963119890minus01
945119890minus01
926119890minus01
908119890minus01
889119890minus01
871119890minus01
853119890minus01
834119890minus01
816119890minus01
(c) Configuration C
1119890+00
98119890minus01
96119890minus01
941119890minus01
921119890minus01
901119890minus01
881119890minus01
861119890minus01
842119890minus01
822119890minus01
802119890minus01
119885
119883 119884
(d) Configuration D
Figure 7 Contours of the volume fraction of oil in the outlet with different configurations
oil in the oil outlet can be up to 100 and it is entirely 100and the fraction of oil in the water outlet can also be aboutless than 96 which is better than other inlet pressures
32 Effect of the Configuration In order to investigate theeffect of the configuration the example is identified asfollows The rotation speed is 1500 rpm The inlet pressure is0002MPa with the other boundary conditions unchangedThis research investigated the separation effect of HIGEErotating oil purifier by changing the configuration such as thelocation of the oil-water mixture inlet oil outlet and wateroutlet in the RPB
Based on previous theoretical and experimental resultsfluids of different densitieswill concentrate ondifferent placesaccordingly under rotation speed The fluid of high densityconcentrates close to the rotation axis while the fluid of lowdensity concentrates away from the rotation axis Thereforefour different configurations are investigated in this researchConfiguration A The oil-water mixture inlet is placed inthe middle of the lower surface of RPB whose diameteris 15mm the water outlet is placed in the outside of thelower surface whose diameter is 5mm and the oil outlet isplaced in the middle of the upper surface whose diameteris 20mm Configuration B The water outlet is also placedin the outside of the lower surface but its width is 25mmwhich is different fromConfigurationAConfigurationCTheoil-water mixture inlet is placed in the outside of the lowersurface whose width is 75mm the water outlet is placedin the side of upper whose diameter is 5mm and the oiloutlet is placed in the middle of the upper face whose widthis 10mm Configuration D The water outlet is placed in the
side of middle which is different from Configuration C Thesectional drawings are extracted Contour plot and graph ofthe outlet volume fraction of oil in the outlet with differentconfigurations are shown in Figures 7 and 8
Figure 7 displays contour plots of the outlet volumefraction of oil in the outlet with different configurations Asshown in Figure 7(a) the volume fraction of oil in the oiloutlet can be up to 100 and the fraction of oil in the wateroutlet can also be about 95 In Figure 7(b) the volumefraction of oil in the oil outlet can be up to 100 and thefraction of oil in the water outlet can also be about morethan 98 Corresponding to the ConfigurationC the volumefraction of oil in the oil outlet can be up to 100 and thefraction of oil in the water outlet can also be about more than95 (Figure 7(c)) The volume fraction of oil in the oil outletcan be up to 100 which is shown in Figure 7(d) and thefraction of oil in the water outlet can also be about less than95
Figure 8 displays graphs of the outlet volume fraction ofoil in the outlet with different configurations The volumefraction of oil in the oil outlet can be up to 100 but it isnot entirely 100 which is shown in Figure 8(a) And thefraction of oil in the water outlet can also be about 95 InFigure 8(b) the volume fraction of oil in the oil outlet can beup to 100 and it is entirely 100 but the fraction of oil in thewater outlet can also be aboutmore than 98Correspondingto Configuration C the volume fraction of oil in the oil outletcan be up to 100 and it is entirely 100 but the fractionof oil in the water outlet can also be about more than 95(Figure 8(c)) As shown in Figure 8(d) the volume fractionof oil in the oil outlet can be up to 100 and it is entirely
Figure 8 Graphs of the volume fraction of oil in the outlet with different configurations
100 but the fraction of oil in the water outlet can also beabout less than 95
Simulation results show that the simulation results indi-cate that the separating efficiency of HIGEE rotating oilpurifier is greatly affected by the configuration ConfigurationD is the best configuration In Configuration D the volumefraction of oil in the oil outlet can be up to 100 and it isentirely 100 but the fraction of oil in the water outlet canalso be about less than 95
33 Discussion Simulation results show that because of dif-ferent densities when the oil from preliminary purificationgoes through the HIGEE field the oil-which has a low
density outflows from the oil outlet in the middle where it isnear the rotation axis while water which has a high densityoutflows from the water outlet is in the edge where it is faraway from the oil outlet
Applying the inlet pressure is for applying an inlet velocityto the oil from preliminary purification When the inletpressure is small which can increase the residence time ofthe oil-water mixture therefore the fluid from preliminarypurification can make a good contact with hydrophilicmaterial in the RPB to get better separation efficiency Theseparation efficiency of HIGEE rotating oil purifier increaseswith the decreasing of inlet pressure in particular when theinlet pressure is 0002MPa the separation efficiency is thebest However a small pressure is not the best choice for the
8 Mathematical Problems in Engineering
inlet pressureTheworking hours will last long when the inletvelocity is very small
The separating efficiency of HIGEE rotating oil purifier isgreatly affected by the configurations Configuration D is thebest configuration The layout of liquid inlet oil outlet andwater outlet of the RPB significantly affected the separatingefficiencyWhen the liquid inlet is placed in the outside of thelower surface of RPB oil outlet is placed in the upper surfacewhere it is near the rotation axis and water outlet is placedin the middle of the side of the RPB where it is far awayfrom the oil outlet the corresponding separating efficiencywas the best In Configuration D the volume fraction of oil inthe oil outlet can be up to 100 and it is entirely 100 butthe fraction of oil in the water outlet can also be about lessthan 95 which is better than other configurations
4 Conclusions
Unlike previous experimental research numerical simulationis employed in this paper to analyze the flow characteristicsinside the RPB and related conclusions are got
(1) The oil-water two-phase flow is simulated based onthe 3D model of the RPB which is established inGambit
(2) The operating conditions on the hydraulic perfor-mance of the RPB are investigated Inlet pressure hasbig effect on the separation efficiency of HIGEE rotat-ing oil purifier The separation efficiency of HIGEErotating oil purifier increases with the decreasing ofinlet pressure in particular when the inlet pressure is0002MPa the separation efficiency is the best
(3) Simulation results also show that the separatingefficiency of HIGEE rotating oil purifier is greatlyaffected by the configuration especially the layout ofliquid inlet oil outlet and water outlet in the RPBWhen the liquid inlet is placed in the outside of thelower surface of RPB oil outlet is placed in the uppersurface where it is near to the rotation axis andwater outlet is placed in the middle of the side ofthe RPB which it is far away from the oil outlet thecorresponding separating efficiency is the best
Compared with theoretical analysis and experimentalresearch numerical simulation has provided an easy andeffective method to design and optimize the HIGEE rotatingoil purifier and other mechanical devices which was widelyused in resources and environmental systems In order tocertificate the numerical results corresponding experimentsneed to be investigated in the future work
Acknowledgments
This research was funded by the Natural Science Founda-tions of China (no 51075007) National High-tech RampD(863) Program (no 2012AA091103) and The Importationand Development of High-Caliber Talents Project of BeijingMunicipal Institutions (CITampTCD 20130316)
References
[1] Z X Xia Contamination Control of Hydraulic System ChinaMachine Press Beijing 1992
[2] C Ramshaw ldquolsquoHiGeersquo distillation-An example of process inten-sificationrdquo Chemical Engineering Science vol 389 pp 13ndash141983
[3] M Keyvani and N C Gardner ldquoOperating characteristics ofrotating bedsrdquo Chemical Engineering Progress vol 85 no 9 pp48ndash52 1989
[4] H S Liu C C Lin S C Wu and H W Hsu ldquoCharacteristicsof a rotating packed bedrdquo Industrial and Engineering ChemistryResearch vol 35 no 10 pp 3590ndash3596 1996
[5] D P RaoA Bhowal andP SGoswami ldquoProcess intensificationin rotating packed beds (HIGee) an Appraisalrdquo Industrial andEngineering Chemistry Research vol 43 no 4 pp 1150ndash11622004
[6] X Li Y Liu Z Li and X Wang ldquoContinues distillation exper-iment with rotating packed bedrdquo Chinese Journal of ChemicalEngineering vol 16 no 4 pp 656ndash662 2008
[7] H Ji S L Nie H M Sun and X H Tang ldquoResearch on on-linepurification of hydraulic oil based on high gravity technologyrdquoChinese Hydraulics amp Pneumatics no 11 pp 1ndash6 2011
[8] C Zheng K Guo Y Feng C Yang and N C GardnerldquoPressure drop of centripetal gas flow through rotating bedsrdquoIndustrial and Engineering Chemistry Research vol 39 no 3 pp829ndash834 2000
[9] A Basic and M P Dudukovic ldquoLiquid holdup in rotatingpacked beds examination of the film flow assumptionrdquo AIChEJournal vol 41 no 2 pp 301ndash316 1995
[10] M J Lockett ldquoFlooding of rotating structured packing and itsapplication to conventional packed columnsrdquo Trans IChemEvol 73 pp 379ndash384 1995
[11] K Guo F Guo Y Feng J Chen C Zheng and N C GardnerldquoSynchronous visual and RTD study on liquid flow in rotatingpacked-bed contractorrdquo Chemical Engineering Science vol 55no 9 pp 1699ndash1706 2000
[12] C Ramshaw and R H Mallinson ldquoMass transfer processrdquo USPatent 4 vol 283 no 255 1981
[13] H H Tung and R S H Mah ldquoModeling liquid mass tranferin HIGee separtion processrdquo Chemical Engineering Communi-cations vol 39 no 1ndash6 pp 147ndash153 1985
[14] S Munjal M P Dudukovc and P Ramachandran ldquoMass-transfer in rotating packed beds-I Development of gas-liquidand liquid-solidmass-transfer correlationsrdquoChemical Engineer-ing Science vol 44 no 10 pp 2245ndash2256 1989
[15] S Munjal M P Dudukovic and P Ramachandran ldquoMass-transfer in rotating packed beds-II Experimental results andcomparisonwith theory and gravity flowrdquoChemical EngineeringScience vol 44 no 10 pp 2257ndash2268 1989
[16] M Kumar and N C Gardner ldquoOperating characteristics ofrotating bedsrdquo Chemical Engineering Science vol 85 no 9 pp48ndash52 1989
[17] M P Kumar andD P Rao ldquoStudies on a high-gravity gas-liquidcontactorrdquo Industrial Engineering Chemistry Research vol 29no 5 pp 917ndash920 1990
[18] S P Singh J H Wilson R M Counce et al ldquoRemoval ofvolatile organic compounds from groundwater using a rotaryair stripperrdquo Industrial and Engineering Chemistry Research vol31 no 2 pp 574ndash580 1992
Mathematical Problems in Engineering 9
[19] Y H Chen C Y Chang W L Su et al ldquoModeling ozonecontacting process in a rotating packed bedrdquo Industrial andEngineering Chemistry Research vol 43 no 1 pp 228ndash2362004
[20] Y S Chen C C Lin and H S Liu ldquoMass tranfer in a rotationgpacked bed with viscous newtonian and non-newtonian fluidsrdquoIndustrial Engineering Chemistry Research vol 44 no 4 pp1043ndash1051 2005
[21] Y S Chen C C Lin and H S Liu ldquoMass tranfer in a rotationgpacked bed with viscous radii of the bedrdquo Industrial EngineeringChemistry Research vol 44 no 20 pp 7868ndash7875 2005
[22] J R Burns and C Ramshaw ldquoProcess intensification visualstudy of liquid maldistribution in rotating packed bedsrdquo Chem-ical Engineering Science vol 51 no 8 pp 1347ndash1352 1996
[23] L J Guo Two-Phase and multiPhase Hydrodynamics XirsquoanJiaotong University Press Xirsquoan China 2002
[24] X Y Kong Advanced Mechanics of Fluid Flow in Porous MediaChinese Science andTechnologyUniversity PressHefei China2010
[25] L S ChengAdvancedMechanics of Fluid Flow in PorousMediaPetroleum Industry Press Beijng China 2010
[26] L Fan RTHaiW XWang Z Lu andZM Yang ldquoApplicationof computational fluid dynamic to model the hydraulic perfor-mance of subsurface flow wetlandsrdquo Journal of EnvironmentalSciences vol 20 no 12 pp 1415ndash1422 2008
[27] Z Wen L C Shi and Y R Ren The Flent ComputationalDynamics Application Guide Tsinghua University Press Bei-jing China 2009
[28] J C Sheng Hydraulic Fluid Mechanics Mechanical IndustryPress Beijing China 1980
[29] Y Yu J M Zhang and L T Jiang Fluent Introductory andAdvanced Course Beijing Institute of Technology Press BeijingChina 2011
22 Mathematical Model In this research the Eulerian mul-tiphase model is applied The phases are water and oil Thedescription of multiphase flow as interpenetrating continuaincorporates the concept of phasic volume fractions which isdefined by 120572
119902in this paper Because there is no temperature
gradient so only the mass conservation and the momentumequations are used Volume fractions represent the spaceoccupied by each phase and the laws of conservation of massand momentum are satisfied by each phase individually [23]
The volume of phase 119902 is 119881119902 which is defined by
119881119902= int
119881
120572119902119889119881 (1)
where119899
sum
119902=1
120572119902= 1 (2)
The effective density of phase 119902 is
120588119902= 120572119902120588119902 (3)
where 120588119902is the physical density of phase 119902 Continuity
equation is shown as
nabla sdot (120588119902120584) = 0 (4)
where 120584 is the vector velocity of the liquid Momentumbalance equation is shown as
nabla sdot (120588119902120584120584) = minusnabla times 119875 + nabla sdot (120583 (nabla times 120584 + (nabla times 120584)
119879)) (5)
where 119875 is the static pressure and 120583 is the viscosity Porousmedia are simulated by adding a momentum source term 119878
119894
to the standard fluid flow equations therefore themomentumbalance in the porous media could be defined as
nabla sdot (120588119902120584120584) = minusnabla times 119875 + nabla sdot (120583 (nabla times 120584 + (nabla times 120584)
119879)) + 119878
119894
(119894 = 119909 119910 119911)
(6)
where 119878119894is the source term for the momentum equation
which is composed of two parts a viscous loss term (the first
Figure 4 Mesh generation of the 3D model
term on the right-hand side of (7)) and inertial loss term (thesecond term on the right-hand side of (7))
where 119863 and 119862 are viscous resistance and inertia losscoefficient matrices respectively When the case is simplehomogeneous porous media the source term is shown as
where 120572 is the permeability and 1198622is the inertial resistance
coefficient119863 and119862 are simply specified as diagonal matriceswith 1120572 and 119862
2 respectively [24 25]
In this paper the Ergun equation is used to deriveporous media input for a packed bed and the laminar flowthrough the porous media is simulated which is similar toa packed bed in this paper and easy to simulate on existingcomputers The permeability and inertial loss coefficients ineach component direction could be identified as
120572 =
1198892
150
1205763
(1 minus 120576)2
1198622=
35
119889
(1 minus 120576)
1205763
(9)
where 119889 is the mean particle diameter and 120576 is the voidfraction [26]
23 Grid Generation and Boundary Condition To solve thegoverning equations appropriate grid generation and bound-ary conditions are specified at all external boundaries basedon the following The 3D model (Figure 3) is meshed intotetrahedral grid (Figure 4) which has about 920538 elementsand 164675 nodes for the 3D computational grid The meshdensity is increased appropriately to improve the computa-tional convergent velocity The technique of finite volume isselected to solve the governing equations Frequently suitablevalues of the underrelaxation factors are adopted to assurethe smooth convergence of the numerical solution In the
Figure 5 Contours of the outlet volume fraction of oil in the outlet with different pressures
Table 1 Material properties of the model
Parameter Unit Water OilVolume fraction mdash 5 95Density kgm3 1000 780Viscosity kgms 0001003 00024
oil-water two-phase flow the material properties [27] andboundary conditions [28 29] in this research can be seen inTables 1 and 2
The material properties and boundary conditions areselected reasonably The standard 119870-120576 model is selectedwhere robustness economy and reasonable accuracy fora wide range of turbulent flows explain its popularity inindustrial flow and heat transfer simulations
3 Results and Discussion
The multiphase flow in porous media of RPB will be nu-merical simulated The effects of operating conditions andconfiguration on the hydraulic performance of the RPB areinvestigated to increase the separation efficiency of HIGEErotating oil purifier
31 Effect of the Inlet Pressure To understand the featuredistribution of inner hydrocyclone separatormore clearly theoutlet pressure of hydrocyclone separator is 0002MPawhichis considered a reference The static pressure is firstly to be
Table 2 Boundary conditions of the model
Description TypePorosity of porous medium 05Mean particle diameter of porous medium 005mmFlow condition of the oil-water mixture TurbulenceViscous model 119870-120576modelInlet of the oil-water mixture Pressure inletOutlet of oil or water Pressure inlet
simulated as shownThis example is identified as follows theconfiguration of the RPB is certain The oil-water mixtureinlet is set near to the middle of the lower surface of the RPBwhose diameter is 15mm The outlet for water and oil is setin the upper surface where the oil outlet is in the middlewhile the water outlet is in the edge The diameter of outletsis 10mm The rotation speed is 1500 rpm The other condi-tions are constant This research investigated the separationefficiency of HIGEE rotating oil purifier by changing the inletpressure The sectional drawings are extracted Contour plotand graph of the outlet volume fraction of oil in the outletwith different pressures are shown in Figures 5 and 6
Figure 5 displays contour plots of the outlet volumefraction of oil in the outlet with different pressures Asshown in Figure 5(a) the liquid inlet pressure is 001MPaThe volume fraction of oil in the oil outlet is not entirely100 and the fraction of oil in the water outlet can be about96 In Figure 5(b) the liquid inlet pressure is 0005MPa
Mathematical Problems in Engineering 5
1119890+00
98119890minus01
96119890minus01
94119890minus01
92119890minus01
9119890minus01
88119890minus01
86119890minus01
Volu
me f
ract
ion
(ker
osen
e)
001 002 003 004 005 006 007 008Position (m)
Oil outletWater outlet
(a) 001MPa
1119890+00
8119890minus01
98119890minus01
96119890minus01
94119890minus01
92119890minus01
9119890minus01
88119890minus01
86119890minus01
Volu
me f
ract
ion
(ker
osen
e)
001 002 003 004 005 006 007 008Position (m)
Oil outletWater outlet
84119890minus01
82119890minus01
(b) 0005MPa
1119890+00
98119890minus01
96119890minus01
94119890minus01
92119890minus01
9119890minus01
88119890minus01
86119890minus01
Volu
me f
ract
ion
(ker
osen
e)
001 002 003 004 005 006 007 008Position (m)
Oil outletWater outlet
(c) 0002MPa
1119890+00
98119890minus01
96119890minus01
94119890minus01
92119890minus01
9119890minus01
88119890minus01
86119890minus01
84119890minus01
82119890minus01
Volu
me f
ract
ion
(ker
osen
e)
001 002 003 004 005 006 007 008Position (m)
Oil outletWater outlet
(d) 0001MPa
Figure 6 Graphs of the outlet volume fraction of oil in the outlet with different pressures
The volume fraction of oil in the oil outlet can be up to 100and the fraction of oil in the water outlet can also be about99 However when the liquid inlet pressure is 0002MPathe volume fraction of oil in the oil outlet can be up to 100as seen in Figure 5(c) and the fraction of oil in the wateroutlet can also be about 96 When the liquid inlet pressureis 0001MPa the volume fraction of oil in the oil outlet can beup to 100 which is shown in Figure 5(d) and the fractionof oil in the water outlet can also be about 98
Figure 6 displays graphs of the outlet volume fraction ofoil in the outlet with different pressures The volume fractionof oil in the oil outlet can be up to 100 but it is not entirely100 as shown in Figure 6(a) and the fraction of oil in thewater outlet can also be about 96 In Figure 6(b) the volumefraction of oil in the oil outlet can be up to 100 and it is
entirely 100 but the fraction of oil in the water outlet canalso be about more than 99 When the liquid inlet pressureis 0002MPa the volume fraction of oil in the oil outlet canbe up to 100 as shown in Figure 6(c) and it is entirely 100but the fraction of oil in the water outlet can also be about lessthan 96 As shown in Figure 6(d) the volume fraction of oilin the oil outlet can be up to 100 and it is entirely 100 butthe fraction of oil in the water outlet can also be about morethan 98
It can be seen from the simulation results that the inletpressure has a big effect on the separation efficiency ofHIGEErotating oil purifier The separation efficiency of HIGEErotating oil purifier improves with the decreasing of inletpressure in particular when the inlet pressure is 0002MPathe separation efficiency is the best The volume fraction of
6 Mathematical Problems in Engineering
1119890+00
966119890minus01
932119890minus01
898119890minus01
864119890minus01
83119890minus01
796119890minus01
762119890minus01
729119890minus01
695119890minus01
661119890minus01
119885
119883 119884
(a) Configuration A
1119890+00
967119890minus01
935119890minus01
902119890minus01
87119890minus01
837119890minus01
804119890minus01
772119890minus01
739119890minus01
707119890minus01
674119890minus01
119885
119883 119884
(b) Configuration B
119885
119883 119884
1119890+00
982119890minus01
963119890minus01
945119890minus01
926119890minus01
908119890minus01
889119890minus01
871119890minus01
853119890minus01
834119890minus01
816119890minus01
(c) Configuration C
1119890+00
98119890minus01
96119890minus01
941119890minus01
921119890minus01
901119890minus01
881119890minus01
861119890minus01
842119890minus01
822119890minus01
802119890minus01
119885
119883 119884
(d) Configuration D
Figure 7 Contours of the volume fraction of oil in the outlet with different configurations
oil in the oil outlet can be up to 100 and it is entirely 100and the fraction of oil in the water outlet can also be aboutless than 96 which is better than other inlet pressures
32 Effect of the Configuration In order to investigate theeffect of the configuration the example is identified asfollows The rotation speed is 1500 rpm The inlet pressure is0002MPa with the other boundary conditions unchangedThis research investigated the separation effect of HIGEErotating oil purifier by changing the configuration such as thelocation of the oil-water mixture inlet oil outlet and wateroutlet in the RPB
Based on previous theoretical and experimental resultsfluids of different densitieswill concentrate ondifferent placesaccordingly under rotation speed The fluid of high densityconcentrates close to the rotation axis while the fluid of lowdensity concentrates away from the rotation axis Thereforefour different configurations are investigated in this researchConfiguration A The oil-water mixture inlet is placed inthe middle of the lower surface of RPB whose diameteris 15mm the water outlet is placed in the outside of thelower surface whose diameter is 5mm and the oil outlet isplaced in the middle of the upper surface whose diameteris 20mm Configuration B The water outlet is also placedin the outside of the lower surface but its width is 25mmwhich is different fromConfigurationAConfigurationCTheoil-water mixture inlet is placed in the outside of the lowersurface whose width is 75mm the water outlet is placedin the side of upper whose diameter is 5mm and the oiloutlet is placed in the middle of the upper face whose widthis 10mm Configuration D The water outlet is placed in the
side of middle which is different from Configuration C Thesectional drawings are extracted Contour plot and graph ofthe outlet volume fraction of oil in the outlet with differentconfigurations are shown in Figures 7 and 8
Figure 7 displays contour plots of the outlet volumefraction of oil in the outlet with different configurations Asshown in Figure 7(a) the volume fraction of oil in the oiloutlet can be up to 100 and the fraction of oil in the wateroutlet can also be about 95 In Figure 7(b) the volumefraction of oil in the oil outlet can be up to 100 and thefraction of oil in the water outlet can also be about morethan 98 Corresponding to the ConfigurationC the volumefraction of oil in the oil outlet can be up to 100 and thefraction of oil in the water outlet can also be about more than95 (Figure 7(c)) The volume fraction of oil in the oil outletcan be up to 100 which is shown in Figure 7(d) and thefraction of oil in the water outlet can also be about less than95
Figure 8 displays graphs of the outlet volume fraction ofoil in the outlet with different configurations The volumefraction of oil in the oil outlet can be up to 100 but it isnot entirely 100 which is shown in Figure 8(a) And thefraction of oil in the water outlet can also be about 95 InFigure 8(b) the volume fraction of oil in the oil outlet can beup to 100 and it is entirely 100 but the fraction of oil in thewater outlet can also be aboutmore than 98Correspondingto Configuration C the volume fraction of oil in the oil outletcan be up to 100 and it is entirely 100 but the fractionof oil in the water outlet can also be about more than 95(Figure 8(c)) As shown in Figure 8(d) the volume fractionof oil in the oil outlet can be up to 100 and it is entirely
Figure 8 Graphs of the volume fraction of oil in the outlet with different configurations
100 but the fraction of oil in the water outlet can also beabout less than 95
Simulation results show that the simulation results indi-cate that the separating efficiency of HIGEE rotating oilpurifier is greatly affected by the configuration ConfigurationD is the best configuration In Configuration D the volumefraction of oil in the oil outlet can be up to 100 and it isentirely 100 but the fraction of oil in the water outlet canalso be about less than 95
33 Discussion Simulation results show that because of dif-ferent densities when the oil from preliminary purificationgoes through the HIGEE field the oil-which has a low
density outflows from the oil outlet in the middle where it isnear the rotation axis while water which has a high densityoutflows from the water outlet is in the edge where it is faraway from the oil outlet
Applying the inlet pressure is for applying an inlet velocityto the oil from preliminary purification When the inletpressure is small which can increase the residence time ofthe oil-water mixture therefore the fluid from preliminarypurification can make a good contact with hydrophilicmaterial in the RPB to get better separation efficiency Theseparation efficiency of HIGEE rotating oil purifier increaseswith the decreasing of inlet pressure in particular when theinlet pressure is 0002MPa the separation efficiency is thebest However a small pressure is not the best choice for the
8 Mathematical Problems in Engineering
inlet pressureTheworking hours will last long when the inletvelocity is very small
The separating efficiency of HIGEE rotating oil purifier isgreatly affected by the configurations Configuration D is thebest configuration The layout of liquid inlet oil outlet andwater outlet of the RPB significantly affected the separatingefficiencyWhen the liquid inlet is placed in the outside of thelower surface of RPB oil outlet is placed in the upper surfacewhere it is near the rotation axis and water outlet is placedin the middle of the side of the RPB where it is far awayfrom the oil outlet the corresponding separating efficiencywas the best In Configuration D the volume fraction of oil inthe oil outlet can be up to 100 and it is entirely 100 butthe fraction of oil in the water outlet can also be about lessthan 95 which is better than other configurations
4 Conclusions
Unlike previous experimental research numerical simulationis employed in this paper to analyze the flow characteristicsinside the RPB and related conclusions are got
(1) The oil-water two-phase flow is simulated based onthe 3D model of the RPB which is established inGambit
(2) The operating conditions on the hydraulic perfor-mance of the RPB are investigated Inlet pressure hasbig effect on the separation efficiency of HIGEE rotat-ing oil purifier The separation efficiency of HIGEErotating oil purifier increases with the decreasing ofinlet pressure in particular when the inlet pressure is0002MPa the separation efficiency is the best
(3) Simulation results also show that the separatingefficiency of HIGEE rotating oil purifier is greatlyaffected by the configuration especially the layout ofliquid inlet oil outlet and water outlet in the RPBWhen the liquid inlet is placed in the outside of thelower surface of RPB oil outlet is placed in the uppersurface where it is near to the rotation axis andwater outlet is placed in the middle of the side ofthe RPB which it is far away from the oil outlet thecorresponding separating efficiency is the best
Compared with theoretical analysis and experimentalresearch numerical simulation has provided an easy andeffective method to design and optimize the HIGEE rotatingoil purifier and other mechanical devices which was widelyused in resources and environmental systems In order tocertificate the numerical results corresponding experimentsneed to be investigated in the future work
Acknowledgments
This research was funded by the Natural Science Founda-tions of China (no 51075007) National High-tech RampD(863) Program (no 2012AA091103) and The Importationand Development of High-Caliber Talents Project of BeijingMunicipal Institutions (CITampTCD 20130316)
References
[1] Z X Xia Contamination Control of Hydraulic System ChinaMachine Press Beijing 1992
[2] C Ramshaw ldquolsquoHiGeersquo distillation-An example of process inten-sificationrdquo Chemical Engineering Science vol 389 pp 13ndash141983
[3] M Keyvani and N C Gardner ldquoOperating characteristics ofrotating bedsrdquo Chemical Engineering Progress vol 85 no 9 pp48ndash52 1989
[4] H S Liu C C Lin S C Wu and H W Hsu ldquoCharacteristicsof a rotating packed bedrdquo Industrial and Engineering ChemistryResearch vol 35 no 10 pp 3590ndash3596 1996
[5] D P RaoA Bhowal andP SGoswami ldquoProcess intensificationin rotating packed beds (HIGee) an Appraisalrdquo Industrial andEngineering Chemistry Research vol 43 no 4 pp 1150ndash11622004
[6] X Li Y Liu Z Li and X Wang ldquoContinues distillation exper-iment with rotating packed bedrdquo Chinese Journal of ChemicalEngineering vol 16 no 4 pp 656ndash662 2008
[7] H Ji S L Nie H M Sun and X H Tang ldquoResearch on on-linepurification of hydraulic oil based on high gravity technologyrdquoChinese Hydraulics amp Pneumatics no 11 pp 1ndash6 2011
[8] C Zheng K Guo Y Feng C Yang and N C GardnerldquoPressure drop of centripetal gas flow through rotating bedsrdquoIndustrial and Engineering Chemistry Research vol 39 no 3 pp829ndash834 2000
[9] A Basic and M P Dudukovic ldquoLiquid holdup in rotatingpacked beds examination of the film flow assumptionrdquo AIChEJournal vol 41 no 2 pp 301ndash316 1995
[10] M J Lockett ldquoFlooding of rotating structured packing and itsapplication to conventional packed columnsrdquo Trans IChemEvol 73 pp 379ndash384 1995
[11] K Guo F Guo Y Feng J Chen C Zheng and N C GardnerldquoSynchronous visual and RTD study on liquid flow in rotatingpacked-bed contractorrdquo Chemical Engineering Science vol 55no 9 pp 1699ndash1706 2000
[12] C Ramshaw and R H Mallinson ldquoMass transfer processrdquo USPatent 4 vol 283 no 255 1981
[13] H H Tung and R S H Mah ldquoModeling liquid mass tranferin HIGee separtion processrdquo Chemical Engineering Communi-cations vol 39 no 1ndash6 pp 147ndash153 1985
[14] S Munjal M P Dudukovc and P Ramachandran ldquoMass-transfer in rotating packed beds-I Development of gas-liquidand liquid-solidmass-transfer correlationsrdquoChemical Engineer-ing Science vol 44 no 10 pp 2245ndash2256 1989
[15] S Munjal M P Dudukovic and P Ramachandran ldquoMass-transfer in rotating packed beds-II Experimental results andcomparisonwith theory and gravity flowrdquoChemical EngineeringScience vol 44 no 10 pp 2257ndash2268 1989
[16] M Kumar and N C Gardner ldquoOperating characteristics ofrotating bedsrdquo Chemical Engineering Science vol 85 no 9 pp48ndash52 1989
[17] M P Kumar andD P Rao ldquoStudies on a high-gravity gas-liquidcontactorrdquo Industrial Engineering Chemistry Research vol 29no 5 pp 917ndash920 1990
[18] S P Singh J H Wilson R M Counce et al ldquoRemoval ofvolatile organic compounds from groundwater using a rotaryair stripperrdquo Industrial and Engineering Chemistry Research vol31 no 2 pp 574ndash580 1992
Mathematical Problems in Engineering 9
[19] Y H Chen C Y Chang W L Su et al ldquoModeling ozonecontacting process in a rotating packed bedrdquo Industrial andEngineering Chemistry Research vol 43 no 1 pp 228ndash2362004
[20] Y S Chen C C Lin and H S Liu ldquoMass tranfer in a rotationgpacked bed with viscous newtonian and non-newtonian fluidsrdquoIndustrial Engineering Chemistry Research vol 44 no 4 pp1043ndash1051 2005
[21] Y S Chen C C Lin and H S Liu ldquoMass tranfer in a rotationgpacked bed with viscous radii of the bedrdquo Industrial EngineeringChemistry Research vol 44 no 20 pp 7868ndash7875 2005
[22] J R Burns and C Ramshaw ldquoProcess intensification visualstudy of liquid maldistribution in rotating packed bedsrdquo Chem-ical Engineering Science vol 51 no 8 pp 1347ndash1352 1996
[23] L J Guo Two-Phase and multiPhase Hydrodynamics XirsquoanJiaotong University Press Xirsquoan China 2002
[24] X Y Kong Advanced Mechanics of Fluid Flow in Porous MediaChinese Science andTechnologyUniversity PressHefei China2010
[25] L S ChengAdvancedMechanics of Fluid Flow in PorousMediaPetroleum Industry Press Beijng China 2010
[26] L Fan RTHaiW XWang Z Lu andZM Yang ldquoApplicationof computational fluid dynamic to model the hydraulic perfor-mance of subsurface flow wetlandsrdquo Journal of EnvironmentalSciences vol 20 no 12 pp 1415ndash1422 2008
[27] Z Wen L C Shi and Y R Ren The Flent ComputationalDynamics Application Guide Tsinghua University Press Bei-jing China 2009
[28] J C Sheng Hydraulic Fluid Mechanics Mechanical IndustryPress Beijing China 1980
[29] Y Yu J M Zhang and L T Jiang Fluent Introductory andAdvanced Course Beijing Institute of Technology Press BeijingChina 2011
Figure 5 Contours of the outlet volume fraction of oil in the outlet with different pressures
Table 1 Material properties of the model
Parameter Unit Water OilVolume fraction mdash 5 95Density kgm3 1000 780Viscosity kgms 0001003 00024
oil-water two-phase flow the material properties [27] andboundary conditions [28 29] in this research can be seen inTables 1 and 2
The material properties and boundary conditions areselected reasonably The standard 119870-120576 model is selectedwhere robustness economy and reasonable accuracy fora wide range of turbulent flows explain its popularity inindustrial flow and heat transfer simulations
3 Results and Discussion
The multiphase flow in porous media of RPB will be nu-merical simulated The effects of operating conditions andconfiguration on the hydraulic performance of the RPB areinvestigated to increase the separation efficiency of HIGEErotating oil purifier
31 Effect of the Inlet Pressure To understand the featuredistribution of inner hydrocyclone separatormore clearly theoutlet pressure of hydrocyclone separator is 0002MPawhichis considered a reference The static pressure is firstly to be
Table 2 Boundary conditions of the model
Description TypePorosity of porous medium 05Mean particle diameter of porous medium 005mmFlow condition of the oil-water mixture TurbulenceViscous model 119870-120576modelInlet of the oil-water mixture Pressure inletOutlet of oil or water Pressure inlet
simulated as shownThis example is identified as follows theconfiguration of the RPB is certain The oil-water mixtureinlet is set near to the middle of the lower surface of the RPBwhose diameter is 15mm The outlet for water and oil is setin the upper surface where the oil outlet is in the middlewhile the water outlet is in the edge The diameter of outletsis 10mm The rotation speed is 1500 rpm The other condi-tions are constant This research investigated the separationefficiency of HIGEE rotating oil purifier by changing the inletpressure The sectional drawings are extracted Contour plotand graph of the outlet volume fraction of oil in the outletwith different pressures are shown in Figures 5 and 6
Figure 5 displays contour plots of the outlet volumefraction of oil in the outlet with different pressures Asshown in Figure 5(a) the liquid inlet pressure is 001MPaThe volume fraction of oil in the oil outlet is not entirely100 and the fraction of oil in the water outlet can be about96 In Figure 5(b) the liquid inlet pressure is 0005MPa
Mathematical Problems in Engineering 5
1119890+00
98119890minus01
96119890minus01
94119890minus01
92119890minus01
9119890minus01
88119890minus01
86119890minus01
Volu
me f
ract
ion
(ker
osen
e)
001 002 003 004 005 006 007 008Position (m)
Oil outletWater outlet
(a) 001MPa
1119890+00
8119890minus01
98119890minus01
96119890minus01
94119890minus01
92119890minus01
9119890minus01
88119890minus01
86119890minus01
Volu
me f
ract
ion
(ker
osen
e)
001 002 003 004 005 006 007 008Position (m)
Oil outletWater outlet
84119890minus01
82119890minus01
(b) 0005MPa
1119890+00
98119890minus01
96119890minus01
94119890minus01
92119890minus01
9119890minus01
88119890minus01
86119890minus01
Volu
me f
ract
ion
(ker
osen
e)
001 002 003 004 005 006 007 008Position (m)
Oil outletWater outlet
(c) 0002MPa
1119890+00
98119890minus01
96119890minus01
94119890minus01
92119890minus01
9119890minus01
88119890minus01
86119890minus01
84119890minus01
82119890minus01
Volu
me f
ract
ion
(ker
osen
e)
001 002 003 004 005 006 007 008Position (m)
Oil outletWater outlet
(d) 0001MPa
Figure 6 Graphs of the outlet volume fraction of oil in the outlet with different pressures
The volume fraction of oil in the oil outlet can be up to 100and the fraction of oil in the water outlet can also be about99 However when the liquid inlet pressure is 0002MPathe volume fraction of oil in the oil outlet can be up to 100as seen in Figure 5(c) and the fraction of oil in the wateroutlet can also be about 96 When the liquid inlet pressureis 0001MPa the volume fraction of oil in the oil outlet can beup to 100 which is shown in Figure 5(d) and the fractionof oil in the water outlet can also be about 98
Figure 6 displays graphs of the outlet volume fraction ofoil in the outlet with different pressures The volume fractionof oil in the oil outlet can be up to 100 but it is not entirely100 as shown in Figure 6(a) and the fraction of oil in thewater outlet can also be about 96 In Figure 6(b) the volumefraction of oil in the oil outlet can be up to 100 and it is
entirely 100 but the fraction of oil in the water outlet canalso be about more than 99 When the liquid inlet pressureis 0002MPa the volume fraction of oil in the oil outlet canbe up to 100 as shown in Figure 6(c) and it is entirely 100but the fraction of oil in the water outlet can also be about lessthan 96 As shown in Figure 6(d) the volume fraction of oilin the oil outlet can be up to 100 and it is entirely 100 butthe fraction of oil in the water outlet can also be about morethan 98
It can be seen from the simulation results that the inletpressure has a big effect on the separation efficiency ofHIGEErotating oil purifier The separation efficiency of HIGEErotating oil purifier improves with the decreasing of inletpressure in particular when the inlet pressure is 0002MPathe separation efficiency is the best The volume fraction of
6 Mathematical Problems in Engineering
1119890+00
966119890minus01
932119890minus01
898119890minus01
864119890minus01
83119890minus01
796119890minus01
762119890minus01
729119890minus01
695119890minus01
661119890minus01
119885
119883 119884
(a) Configuration A
1119890+00
967119890minus01
935119890minus01
902119890minus01
87119890minus01
837119890minus01
804119890minus01
772119890minus01
739119890minus01
707119890minus01
674119890minus01
119885
119883 119884
(b) Configuration B
119885
119883 119884
1119890+00
982119890minus01
963119890minus01
945119890minus01
926119890minus01
908119890minus01
889119890minus01
871119890minus01
853119890minus01
834119890minus01
816119890minus01
(c) Configuration C
1119890+00
98119890minus01
96119890minus01
941119890minus01
921119890minus01
901119890minus01
881119890minus01
861119890minus01
842119890minus01
822119890minus01
802119890minus01
119885
119883 119884
(d) Configuration D
Figure 7 Contours of the volume fraction of oil in the outlet with different configurations
oil in the oil outlet can be up to 100 and it is entirely 100and the fraction of oil in the water outlet can also be aboutless than 96 which is better than other inlet pressures
32 Effect of the Configuration In order to investigate theeffect of the configuration the example is identified asfollows The rotation speed is 1500 rpm The inlet pressure is0002MPa with the other boundary conditions unchangedThis research investigated the separation effect of HIGEErotating oil purifier by changing the configuration such as thelocation of the oil-water mixture inlet oil outlet and wateroutlet in the RPB
Based on previous theoretical and experimental resultsfluids of different densitieswill concentrate ondifferent placesaccordingly under rotation speed The fluid of high densityconcentrates close to the rotation axis while the fluid of lowdensity concentrates away from the rotation axis Thereforefour different configurations are investigated in this researchConfiguration A The oil-water mixture inlet is placed inthe middle of the lower surface of RPB whose diameteris 15mm the water outlet is placed in the outside of thelower surface whose diameter is 5mm and the oil outlet isplaced in the middle of the upper surface whose diameteris 20mm Configuration B The water outlet is also placedin the outside of the lower surface but its width is 25mmwhich is different fromConfigurationAConfigurationCTheoil-water mixture inlet is placed in the outside of the lowersurface whose width is 75mm the water outlet is placedin the side of upper whose diameter is 5mm and the oiloutlet is placed in the middle of the upper face whose widthis 10mm Configuration D The water outlet is placed in the
side of middle which is different from Configuration C Thesectional drawings are extracted Contour plot and graph ofthe outlet volume fraction of oil in the outlet with differentconfigurations are shown in Figures 7 and 8
Figure 7 displays contour plots of the outlet volumefraction of oil in the outlet with different configurations Asshown in Figure 7(a) the volume fraction of oil in the oiloutlet can be up to 100 and the fraction of oil in the wateroutlet can also be about 95 In Figure 7(b) the volumefraction of oil in the oil outlet can be up to 100 and thefraction of oil in the water outlet can also be about morethan 98 Corresponding to the ConfigurationC the volumefraction of oil in the oil outlet can be up to 100 and thefraction of oil in the water outlet can also be about more than95 (Figure 7(c)) The volume fraction of oil in the oil outletcan be up to 100 which is shown in Figure 7(d) and thefraction of oil in the water outlet can also be about less than95
Figure 8 displays graphs of the outlet volume fraction ofoil in the outlet with different configurations The volumefraction of oil in the oil outlet can be up to 100 but it isnot entirely 100 which is shown in Figure 8(a) And thefraction of oil in the water outlet can also be about 95 InFigure 8(b) the volume fraction of oil in the oil outlet can beup to 100 and it is entirely 100 but the fraction of oil in thewater outlet can also be aboutmore than 98Correspondingto Configuration C the volume fraction of oil in the oil outletcan be up to 100 and it is entirely 100 but the fractionof oil in the water outlet can also be about more than 95(Figure 8(c)) As shown in Figure 8(d) the volume fractionof oil in the oil outlet can be up to 100 and it is entirely
Figure 8 Graphs of the volume fraction of oil in the outlet with different configurations
100 but the fraction of oil in the water outlet can also beabout less than 95
Simulation results show that the simulation results indi-cate that the separating efficiency of HIGEE rotating oilpurifier is greatly affected by the configuration ConfigurationD is the best configuration In Configuration D the volumefraction of oil in the oil outlet can be up to 100 and it isentirely 100 but the fraction of oil in the water outlet canalso be about less than 95
33 Discussion Simulation results show that because of dif-ferent densities when the oil from preliminary purificationgoes through the HIGEE field the oil-which has a low
density outflows from the oil outlet in the middle where it isnear the rotation axis while water which has a high densityoutflows from the water outlet is in the edge where it is faraway from the oil outlet
Applying the inlet pressure is for applying an inlet velocityto the oil from preliminary purification When the inletpressure is small which can increase the residence time ofthe oil-water mixture therefore the fluid from preliminarypurification can make a good contact with hydrophilicmaterial in the RPB to get better separation efficiency Theseparation efficiency of HIGEE rotating oil purifier increaseswith the decreasing of inlet pressure in particular when theinlet pressure is 0002MPa the separation efficiency is thebest However a small pressure is not the best choice for the
8 Mathematical Problems in Engineering
inlet pressureTheworking hours will last long when the inletvelocity is very small
The separating efficiency of HIGEE rotating oil purifier isgreatly affected by the configurations Configuration D is thebest configuration The layout of liquid inlet oil outlet andwater outlet of the RPB significantly affected the separatingefficiencyWhen the liquid inlet is placed in the outside of thelower surface of RPB oil outlet is placed in the upper surfacewhere it is near the rotation axis and water outlet is placedin the middle of the side of the RPB where it is far awayfrom the oil outlet the corresponding separating efficiencywas the best In Configuration D the volume fraction of oil inthe oil outlet can be up to 100 and it is entirely 100 butthe fraction of oil in the water outlet can also be about lessthan 95 which is better than other configurations
4 Conclusions
Unlike previous experimental research numerical simulationis employed in this paper to analyze the flow characteristicsinside the RPB and related conclusions are got
(1) The oil-water two-phase flow is simulated based onthe 3D model of the RPB which is established inGambit
(2) The operating conditions on the hydraulic perfor-mance of the RPB are investigated Inlet pressure hasbig effect on the separation efficiency of HIGEE rotat-ing oil purifier The separation efficiency of HIGEErotating oil purifier increases with the decreasing ofinlet pressure in particular when the inlet pressure is0002MPa the separation efficiency is the best
(3) Simulation results also show that the separatingefficiency of HIGEE rotating oil purifier is greatlyaffected by the configuration especially the layout ofliquid inlet oil outlet and water outlet in the RPBWhen the liquid inlet is placed in the outside of thelower surface of RPB oil outlet is placed in the uppersurface where it is near to the rotation axis andwater outlet is placed in the middle of the side ofthe RPB which it is far away from the oil outlet thecorresponding separating efficiency is the best
Compared with theoretical analysis and experimentalresearch numerical simulation has provided an easy andeffective method to design and optimize the HIGEE rotatingoil purifier and other mechanical devices which was widelyused in resources and environmental systems In order tocertificate the numerical results corresponding experimentsneed to be investigated in the future work
Acknowledgments
This research was funded by the Natural Science Founda-tions of China (no 51075007) National High-tech RampD(863) Program (no 2012AA091103) and The Importationand Development of High-Caliber Talents Project of BeijingMunicipal Institutions (CITampTCD 20130316)
References
[1] Z X Xia Contamination Control of Hydraulic System ChinaMachine Press Beijing 1992
[2] C Ramshaw ldquolsquoHiGeersquo distillation-An example of process inten-sificationrdquo Chemical Engineering Science vol 389 pp 13ndash141983
[3] M Keyvani and N C Gardner ldquoOperating characteristics ofrotating bedsrdquo Chemical Engineering Progress vol 85 no 9 pp48ndash52 1989
[4] H S Liu C C Lin S C Wu and H W Hsu ldquoCharacteristicsof a rotating packed bedrdquo Industrial and Engineering ChemistryResearch vol 35 no 10 pp 3590ndash3596 1996
[5] D P RaoA Bhowal andP SGoswami ldquoProcess intensificationin rotating packed beds (HIGee) an Appraisalrdquo Industrial andEngineering Chemistry Research vol 43 no 4 pp 1150ndash11622004
[6] X Li Y Liu Z Li and X Wang ldquoContinues distillation exper-iment with rotating packed bedrdquo Chinese Journal of ChemicalEngineering vol 16 no 4 pp 656ndash662 2008
[7] H Ji S L Nie H M Sun and X H Tang ldquoResearch on on-linepurification of hydraulic oil based on high gravity technologyrdquoChinese Hydraulics amp Pneumatics no 11 pp 1ndash6 2011
[8] C Zheng K Guo Y Feng C Yang and N C GardnerldquoPressure drop of centripetal gas flow through rotating bedsrdquoIndustrial and Engineering Chemistry Research vol 39 no 3 pp829ndash834 2000
[9] A Basic and M P Dudukovic ldquoLiquid holdup in rotatingpacked beds examination of the film flow assumptionrdquo AIChEJournal vol 41 no 2 pp 301ndash316 1995
[10] M J Lockett ldquoFlooding of rotating structured packing and itsapplication to conventional packed columnsrdquo Trans IChemEvol 73 pp 379ndash384 1995
[11] K Guo F Guo Y Feng J Chen C Zheng and N C GardnerldquoSynchronous visual and RTD study on liquid flow in rotatingpacked-bed contractorrdquo Chemical Engineering Science vol 55no 9 pp 1699ndash1706 2000
[12] C Ramshaw and R H Mallinson ldquoMass transfer processrdquo USPatent 4 vol 283 no 255 1981
[13] H H Tung and R S H Mah ldquoModeling liquid mass tranferin HIGee separtion processrdquo Chemical Engineering Communi-cations vol 39 no 1ndash6 pp 147ndash153 1985
[14] S Munjal M P Dudukovc and P Ramachandran ldquoMass-transfer in rotating packed beds-I Development of gas-liquidand liquid-solidmass-transfer correlationsrdquoChemical Engineer-ing Science vol 44 no 10 pp 2245ndash2256 1989
[15] S Munjal M P Dudukovic and P Ramachandran ldquoMass-transfer in rotating packed beds-II Experimental results andcomparisonwith theory and gravity flowrdquoChemical EngineeringScience vol 44 no 10 pp 2257ndash2268 1989
[16] M Kumar and N C Gardner ldquoOperating characteristics ofrotating bedsrdquo Chemical Engineering Science vol 85 no 9 pp48ndash52 1989
[17] M P Kumar andD P Rao ldquoStudies on a high-gravity gas-liquidcontactorrdquo Industrial Engineering Chemistry Research vol 29no 5 pp 917ndash920 1990
[18] S P Singh J H Wilson R M Counce et al ldquoRemoval ofvolatile organic compounds from groundwater using a rotaryair stripperrdquo Industrial and Engineering Chemistry Research vol31 no 2 pp 574ndash580 1992
Mathematical Problems in Engineering 9
[19] Y H Chen C Y Chang W L Su et al ldquoModeling ozonecontacting process in a rotating packed bedrdquo Industrial andEngineering Chemistry Research vol 43 no 1 pp 228ndash2362004
[20] Y S Chen C C Lin and H S Liu ldquoMass tranfer in a rotationgpacked bed with viscous newtonian and non-newtonian fluidsrdquoIndustrial Engineering Chemistry Research vol 44 no 4 pp1043ndash1051 2005
[21] Y S Chen C C Lin and H S Liu ldquoMass tranfer in a rotationgpacked bed with viscous radii of the bedrdquo Industrial EngineeringChemistry Research vol 44 no 20 pp 7868ndash7875 2005
[22] J R Burns and C Ramshaw ldquoProcess intensification visualstudy of liquid maldistribution in rotating packed bedsrdquo Chem-ical Engineering Science vol 51 no 8 pp 1347ndash1352 1996
[23] L J Guo Two-Phase and multiPhase Hydrodynamics XirsquoanJiaotong University Press Xirsquoan China 2002
[24] X Y Kong Advanced Mechanics of Fluid Flow in Porous MediaChinese Science andTechnologyUniversity PressHefei China2010
[25] L S ChengAdvancedMechanics of Fluid Flow in PorousMediaPetroleum Industry Press Beijng China 2010
[26] L Fan RTHaiW XWang Z Lu andZM Yang ldquoApplicationof computational fluid dynamic to model the hydraulic perfor-mance of subsurface flow wetlandsrdquo Journal of EnvironmentalSciences vol 20 no 12 pp 1415ndash1422 2008
[27] Z Wen L C Shi and Y R Ren The Flent ComputationalDynamics Application Guide Tsinghua University Press Bei-jing China 2009
[28] J C Sheng Hydraulic Fluid Mechanics Mechanical IndustryPress Beijing China 1980
[29] Y Yu J M Zhang and L T Jiang Fluent Introductory andAdvanced Course Beijing Institute of Technology Press BeijingChina 2011
Figure 6 Graphs of the outlet volume fraction of oil in the outlet with different pressures
The volume fraction of oil in the oil outlet can be up to 100and the fraction of oil in the water outlet can also be about99 However when the liquid inlet pressure is 0002MPathe volume fraction of oil in the oil outlet can be up to 100as seen in Figure 5(c) and the fraction of oil in the wateroutlet can also be about 96 When the liquid inlet pressureis 0001MPa the volume fraction of oil in the oil outlet can beup to 100 which is shown in Figure 5(d) and the fractionof oil in the water outlet can also be about 98
Figure 6 displays graphs of the outlet volume fraction ofoil in the outlet with different pressures The volume fractionof oil in the oil outlet can be up to 100 but it is not entirely100 as shown in Figure 6(a) and the fraction of oil in thewater outlet can also be about 96 In Figure 6(b) the volumefraction of oil in the oil outlet can be up to 100 and it is
entirely 100 but the fraction of oil in the water outlet canalso be about more than 99 When the liquid inlet pressureis 0002MPa the volume fraction of oil in the oil outlet canbe up to 100 as shown in Figure 6(c) and it is entirely 100but the fraction of oil in the water outlet can also be about lessthan 96 As shown in Figure 6(d) the volume fraction of oilin the oil outlet can be up to 100 and it is entirely 100 butthe fraction of oil in the water outlet can also be about morethan 98
It can be seen from the simulation results that the inletpressure has a big effect on the separation efficiency ofHIGEErotating oil purifier The separation efficiency of HIGEErotating oil purifier improves with the decreasing of inletpressure in particular when the inlet pressure is 0002MPathe separation efficiency is the best The volume fraction of
6 Mathematical Problems in Engineering
1119890+00
966119890minus01
932119890minus01
898119890minus01
864119890minus01
83119890minus01
796119890minus01
762119890minus01
729119890minus01
695119890minus01
661119890minus01
119885
119883 119884
(a) Configuration A
1119890+00
967119890minus01
935119890minus01
902119890minus01
87119890minus01
837119890minus01
804119890minus01
772119890minus01
739119890minus01
707119890minus01
674119890minus01
119885
119883 119884
(b) Configuration B
119885
119883 119884
1119890+00
982119890minus01
963119890minus01
945119890minus01
926119890minus01
908119890minus01
889119890minus01
871119890minus01
853119890minus01
834119890minus01
816119890minus01
(c) Configuration C
1119890+00
98119890minus01
96119890minus01
941119890minus01
921119890minus01
901119890minus01
881119890minus01
861119890minus01
842119890minus01
822119890minus01
802119890minus01
119885
119883 119884
(d) Configuration D
Figure 7 Contours of the volume fraction of oil in the outlet with different configurations
oil in the oil outlet can be up to 100 and it is entirely 100and the fraction of oil in the water outlet can also be aboutless than 96 which is better than other inlet pressures
32 Effect of the Configuration In order to investigate theeffect of the configuration the example is identified asfollows The rotation speed is 1500 rpm The inlet pressure is0002MPa with the other boundary conditions unchangedThis research investigated the separation effect of HIGEErotating oil purifier by changing the configuration such as thelocation of the oil-water mixture inlet oil outlet and wateroutlet in the RPB
Based on previous theoretical and experimental resultsfluids of different densitieswill concentrate ondifferent placesaccordingly under rotation speed The fluid of high densityconcentrates close to the rotation axis while the fluid of lowdensity concentrates away from the rotation axis Thereforefour different configurations are investigated in this researchConfiguration A The oil-water mixture inlet is placed inthe middle of the lower surface of RPB whose diameteris 15mm the water outlet is placed in the outside of thelower surface whose diameter is 5mm and the oil outlet isplaced in the middle of the upper surface whose diameteris 20mm Configuration B The water outlet is also placedin the outside of the lower surface but its width is 25mmwhich is different fromConfigurationAConfigurationCTheoil-water mixture inlet is placed in the outside of the lowersurface whose width is 75mm the water outlet is placedin the side of upper whose diameter is 5mm and the oiloutlet is placed in the middle of the upper face whose widthis 10mm Configuration D The water outlet is placed in the
side of middle which is different from Configuration C Thesectional drawings are extracted Contour plot and graph ofthe outlet volume fraction of oil in the outlet with differentconfigurations are shown in Figures 7 and 8
Figure 7 displays contour plots of the outlet volumefraction of oil in the outlet with different configurations Asshown in Figure 7(a) the volume fraction of oil in the oiloutlet can be up to 100 and the fraction of oil in the wateroutlet can also be about 95 In Figure 7(b) the volumefraction of oil in the oil outlet can be up to 100 and thefraction of oil in the water outlet can also be about morethan 98 Corresponding to the ConfigurationC the volumefraction of oil in the oil outlet can be up to 100 and thefraction of oil in the water outlet can also be about more than95 (Figure 7(c)) The volume fraction of oil in the oil outletcan be up to 100 which is shown in Figure 7(d) and thefraction of oil in the water outlet can also be about less than95
Figure 8 displays graphs of the outlet volume fraction ofoil in the outlet with different configurations The volumefraction of oil in the oil outlet can be up to 100 but it isnot entirely 100 which is shown in Figure 8(a) And thefraction of oil in the water outlet can also be about 95 InFigure 8(b) the volume fraction of oil in the oil outlet can beup to 100 and it is entirely 100 but the fraction of oil in thewater outlet can also be aboutmore than 98Correspondingto Configuration C the volume fraction of oil in the oil outletcan be up to 100 and it is entirely 100 but the fractionof oil in the water outlet can also be about more than 95(Figure 8(c)) As shown in Figure 8(d) the volume fractionof oil in the oil outlet can be up to 100 and it is entirely
Figure 8 Graphs of the volume fraction of oil in the outlet with different configurations
100 but the fraction of oil in the water outlet can also beabout less than 95
Simulation results show that the simulation results indi-cate that the separating efficiency of HIGEE rotating oilpurifier is greatly affected by the configuration ConfigurationD is the best configuration In Configuration D the volumefraction of oil in the oil outlet can be up to 100 and it isentirely 100 but the fraction of oil in the water outlet canalso be about less than 95
33 Discussion Simulation results show that because of dif-ferent densities when the oil from preliminary purificationgoes through the HIGEE field the oil-which has a low
density outflows from the oil outlet in the middle where it isnear the rotation axis while water which has a high densityoutflows from the water outlet is in the edge where it is faraway from the oil outlet
Applying the inlet pressure is for applying an inlet velocityto the oil from preliminary purification When the inletpressure is small which can increase the residence time ofthe oil-water mixture therefore the fluid from preliminarypurification can make a good contact with hydrophilicmaterial in the RPB to get better separation efficiency Theseparation efficiency of HIGEE rotating oil purifier increaseswith the decreasing of inlet pressure in particular when theinlet pressure is 0002MPa the separation efficiency is thebest However a small pressure is not the best choice for the
8 Mathematical Problems in Engineering
inlet pressureTheworking hours will last long when the inletvelocity is very small
The separating efficiency of HIGEE rotating oil purifier isgreatly affected by the configurations Configuration D is thebest configuration The layout of liquid inlet oil outlet andwater outlet of the RPB significantly affected the separatingefficiencyWhen the liquid inlet is placed in the outside of thelower surface of RPB oil outlet is placed in the upper surfacewhere it is near the rotation axis and water outlet is placedin the middle of the side of the RPB where it is far awayfrom the oil outlet the corresponding separating efficiencywas the best In Configuration D the volume fraction of oil inthe oil outlet can be up to 100 and it is entirely 100 butthe fraction of oil in the water outlet can also be about lessthan 95 which is better than other configurations
4 Conclusions
Unlike previous experimental research numerical simulationis employed in this paper to analyze the flow characteristicsinside the RPB and related conclusions are got
(1) The oil-water two-phase flow is simulated based onthe 3D model of the RPB which is established inGambit
(2) The operating conditions on the hydraulic perfor-mance of the RPB are investigated Inlet pressure hasbig effect on the separation efficiency of HIGEE rotat-ing oil purifier The separation efficiency of HIGEErotating oil purifier increases with the decreasing ofinlet pressure in particular when the inlet pressure is0002MPa the separation efficiency is the best
(3) Simulation results also show that the separatingefficiency of HIGEE rotating oil purifier is greatlyaffected by the configuration especially the layout ofliquid inlet oil outlet and water outlet in the RPBWhen the liquid inlet is placed in the outside of thelower surface of RPB oil outlet is placed in the uppersurface where it is near to the rotation axis andwater outlet is placed in the middle of the side ofthe RPB which it is far away from the oil outlet thecorresponding separating efficiency is the best
Compared with theoretical analysis and experimentalresearch numerical simulation has provided an easy andeffective method to design and optimize the HIGEE rotatingoil purifier and other mechanical devices which was widelyused in resources and environmental systems In order tocertificate the numerical results corresponding experimentsneed to be investigated in the future work
Acknowledgments
This research was funded by the Natural Science Founda-tions of China (no 51075007) National High-tech RampD(863) Program (no 2012AA091103) and The Importationand Development of High-Caliber Talents Project of BeijingMunicipal Institutions (CITampTCD 20130316)
References
[1] Z X Xia Contamination Control of Hydraulic System ChinaMachine Press Beijing 1992
[2] C Ramshaw ldquolsquoHiGeersquo distillation-An example of process inten-sificationrdquo Chemical Engineering Science vol 389 pp 13ndash141983
[3] M Keyvani and N C Gardner ldquoOperating characteristics ofrotating bedsrdquo Chemical Engineering Progress vol 85 no 9 pp48ndash52 1989
[4] H S Liu C C Lin S C Wu and H W Hsu ldquoCharacteristicsof a rotating packed bedrdquo Industrial and Engineering ChemistryResearch vol 35 no 10 pp 3590ndash3596 1996
[5] D P RaoA Bhowal andP SGoswami ldquoProcess intensificationin rotating packed beds (HIGee) an Appraisalrdquo Industrial andEngineering Chemistry Research vol 43 no 4 pp 1150ndash11622004
[6] X Li Y Liu Z Li and X Wang ldquoContinues distillation exper-iment with rotating packed bedrdquo Chinese Journal of ChemicalEngineering vol 16 no 4 pp 656ndash662 2008
[7] H Ji S L Nie H M Sun and X H Tang ldquoResearch on on-linepurification of hydraulic oil based on high gravity technologyrdquoChinese Hydraulics amp Pneumatics no 11 pp 1ndash6 2011
[8] C Zheng K Guo Y Feng C Yang and N C GardnerldquoPressure drop of centripetal gas flow through rotating bedsrdquoIndustrial and Engineering Chemistry Research vol 39 no 3 pp829ndash834 2000
[9] A Basic and M P Dudukovic ldquoLiquid holdup in rotatingpacked beds examination of the film flow assumptionrdquo AIChEJournal vol 41 no 2 pp 301ndash316 1995
[10] M J Lockett ldquoFlooding of rotating structured packing and itsapplication to conventional packed columnsrdquo Trans IChemEvol 73 pp 379ndash384 1995
[11] K Guo F Guo Y Feng J Chen C Zheng and N C GardnerldquoSynchronous visual and RTD study on liquid flow in rotatingpacked-bed contractorrdquo Chemical Engineering Science vol 55no 9 pp 1699ndash1706 2000
[12] C Ramshaw and R H Mallinson ldquoMass transfer processrdquo USPatent 4 vol 283 no 255 1981
[13] H H Tung and R S H Mah ldquoModeling liquid mass tranferin HIGee separtion processrdquo Chemical Engineering Communi-cations vol 39 no 1ndash6 pp 147ndash153 1985
[14] S Munjal M P Dudukovc and P Ramachandran ldquoMass-transfer in rotating packed beds-I Development of gas-liquidand liquid-solidmass-transfer correlationsrdquoChemical Engineer-ing Science vol 44 no 10 pp 2245ndash2256 1989
[15] S Munjal M P Dudukovic and P Ramachandran ldquoMass-transfer in rotating packed beds-II Experimental results andcomparisonwith theory and gravity flowrdquoChemical EngineeringScience vol 44 no 10 pp 2257ndash2268 1989
[16] M Kumar and N C Gardner ldquoOperating characteristics ofrotating bedsrdquo Chemical Engineering Science vol 85 no 9 pp48ndash52 1989
[17] M P Kumar andD P Rao ldquoStudies on a high-gravity gas-liquidcontactorrdquo Industrial Engineering Chemistry Research vol 29no 5 pp 917ndash920 1990
[18] S P Singh J H Wilson R M Counce et al ldquoRemoval ofvolatile organic compounds from groundwater using a rotaryair stripperrdquo Industrial and Engineering Chemistry Research vol31 no 2 pp 574ndash580 1992
Mathematical Problems in Engineering 9
[19] Y H Chen C Y Chang W L Su et al ldquoModeling ozonecontacting process in a rotating packed bedrdquo Industrial andEngineering Chemistry Research vol 43 no 1 pp 228ndash2362004
[20] Y S Chen C C Lin and H S Liu ldquoMass tranfer in a rotationgpacked bed with viscous newtonian and non-newtonian fluidsrdquoIndustrial Engineering Chemistry Research vol 44 no 4 pp1043ndash1051 2005
[21] Y S Chen C C Lin and H S Liu ldquoMass tranfer in a rotationgpacked bed with viscous radii of the bedrdquo Industrial EngineeringChemistry Research vol 44 no 20 pp 7868ndash7875 2005
[22] J R Burns and C Ramshaw ldquoProcess intensification visualstudy of liquid maldistribution in rotating packed bedsrdquo Chem-ical Engineering Science vol 51 no 8 pp 1347ndash1352 1996
[23] L J Guo Two-Phase and multiPhase Hydrodynamics XirsquoanJiaotong University Press Xirsquoan China 2002
[24] X Y Kong Advanced Mechanics of Fluid Flow in Porous MediaChinese Science andTechnologyUniversity PressHefei China2010
[25] L S ChengAdvancedMechanics of Fluid Flow in PorousMediaPetroleum Industry Press Beijng China 2010
[26] L Fan RTHaiW XWang Z Lu andZM Yang ldquoApplicationof computational fluid dynamic to model the hydraulic perfor-mance of subsurface flow wetlandsrdquo Journal of EnvironmentalSciences vol 20 no 12 pp 1415ndash1422 2008
[27] Z Wen L C Shi and Y R Ren The Flent ComputationalDynamics Application Guide Tsinghua University Press Bei-jing China 2009
[28] J C Sheng Hydraulic Fluid Mechanics Mechanical IndustryPress Beijing China 1980
[29] Y Yu J M Zhang and L T Jiang Fluent Introductory andAdvanced Course Beijing Institute of Technology Press BeijingChina 2011
Figure 7 Contours of the volume fraction of oil in the outlet with different configurations
oil in the oil outlet can be up to 100 and it is entirely 100and the fraction of oil in the water outlet can also be aboutless than 96 which is better than other inlet pressures
32 Effect of the Configuration In order to investigate theeffect of the configuration the example is identified asfollows The rotation speed is 1500 rpm The inlet pressure is0002MPa with the other boundary conditions unchangedThis research investigated the separation effect of HIGEErotating oil purifier by changing the configuration such as thelocation of the oil-water mixture inlet oil outlet and wateroutlet in the RPB
Based on previous theoretical and experimental resultsfluids of different densitieswill concentrate ondifferent placesaccordingly under rotation speed The fluid of high densityconcentrates close to the rotation axis while the fluid of lowdensity concentrates away from the rotation axis Thereforefour different configurations are investigated in this researchConfiguration A The oil-water mixture inlet is placed inthe middle of the lower surface of RPB whose diameteris 15mm the water outlet is placed in the outside of thelower surface whose diameter is 5mm and the oil outlet isplaced in the middle of the upper surface whose diameteris 20mm Configuration B The water outlet is also placedin the outside of the lower surface but its width is 25mmwhich is different fromConfigurationAConfigurationCTheoil-water mixture inlet is placed in the outside of the lowersurface whose width is 75mm the water outlet is placedin the side of upper whose diameter is 5mm and the oiloutlet is placed in the middle of the upper face whose widthis 10mm Configuration D The water outlet is placed in the
side of middle which is different from Configuration C Thesectional drawings are extracted Contour plot and graph ofthe outlet volume fraction of oil in the outlet with differentconfigurations are shown in Figures 7 and 8
Figure 7 displays contour plots of the outlet volumefraction of oil in the outlet with different configurations Asshown in Figure 7(a) the volume fraction of oil in the oiloutlet can be up to 100 and the fraction of oil in the wateroutlet can also be about 95 In Figure 7(b) the volumefraction of oil in the oil outlet can be up to 100 and thefraction of oil in the water outlet can also be about morethan 98 Corresponding to the ConfigurationC the volumefraction of oil in the oil outlet can be up to 100 and thefraction of oil in the water outlet can also be about more than95 (Figure 7(c)) The volume fraction of oil in the oil outletcan be up to 100 which is shown in Figure 7(d) and thefraction of oil in the water outlet can also be about less than95
Figure 8 displays graphs of the outlet volume fraction ofoil in the outlet with different configurations The volumefraction of oil in the oil outlet can be up to 100 but it isnot entirely 100 which is shown in Figure 8(a) And thefraction of oil in the water outlet can also be about 95 InFigure 8(b) the volume fraction of oil in the oil outlet can beup to 100 and it is entirely 100 but the fraction of oil in thewater outlet can also be aboutmore than 98Correspondingto Configuration C the volume fraction of oil in the oil outletcan be up to 100 and it is entirely 100 but the fractionof oil in the water outlet can also be about more than 95(Figure 8(c)) As shown in Figure 8(d) the volume fractionof oil in the oil outlet can be up to 100 and it is entirely
Figure 8 Graphs of the volume fraction of oil in the outlet with different configurations
100 but the fraction of oil in the water outlet can also beabout less than 95
Simulation results show that the simulation results indi-cate that the separating efficiency of HIGEE rotating oilpurifier is greatly affected by the configuration ConfigurationD is the best configuration In Configuration D the volumefraction of oil in the oil outlet can be up to 100 and it isentirely 100 but the fraction of oil in the water outlet canalso be about less than 95
33 Discussion Simulation results show that because of dif-ferent densities when the oil from preliminary purificationgoes through the HIGEE field the oil-which has a low
density outflows from the oil outlet in the middle where it isnear the rotation axis while water which has a high densityoutflows from the water outlet is in the edge where it is faraway from the oil outlet
Applying the inlet pressure is for applying an inlet velocityto the oil from preliminary purification When the inletpressure is small which can increase the residence time ofthe oil-water mixture therefore the fluid from preliminarypurification can make a good contact with hydrophilicmaterial in the RPB to get better separation efficiency Theseparation efficiency of HIGEE rotating oil purifier increaseswith the decreasing of inlet pressure in particular when theinlet pressure is 0002MPa the separation efficiency is thebest However a small pressure is not the best choice for the
8 Mathematical Problems in Engineering
inlet pressureTheworking hours will last long when the inletvelocity is very small
The separating efficiency of HIGEE rotating oil purifier isgreatly affected by the configurations Configuration D is thebest configuration The layout of liquid inlet oil outlet andwater outlet of the RPB significantly affected the separatingefficiencyWhen the liquid inlet is placed in the outside of thelower surface of RPB oil outlet is placed in the upper surfacewhere it is near the rotation axis and water outlet is placedin the middle of the side of the RPB where it is far awayfrom the oil outlet the corresponding separating efficiencywas the best In Configuration D the volume fraction of oil inthe oil outlet can be up to 100 and it is entirely 100 butthe fraction of oil in the water outlet can also be about lessthan 95 which is better than other configurations
4 Conclusions
Unlike previous experimental research numerical simulationis employed in this paper to analyze the flow characteristicsinside the RPB and related conclusions are got
(1) The oil-water two-phase flow is simulated based onthe 3D model of the RPB which is established inGambit
(2) The operating conditions on the hydraulic perfor-mance of the RPB are investigated Inlet pressure hasbig effect on the separation efficiency of HIGEE rotat-ing oil purifier The separation efficiency of HIGEErotating oil purifier increases with the decreasing ofinlet pressure in particular when the inlet pressure is0002MPa the separation efficiency is the best
(3) Simulation results also show that the separatingefficiency of HIGEE rotating oil purifier is greatlyaffected by the configuration especially the layout ofliquid inlet oil outlet and water outlet in the RPBWhen the liquid inlet is placed in the outside of thelower surface of RPB oil outlet is placed in the uppersurface where it is near to the rotation axis andwater outlet is placed in the middle of the side ofthe RPB which it is far away from the oil outlet thecorresponding separating efficiency is the best
Compared with theoretical analysis and experimentalresearch numerical simulation has provided an easy andeffective method to design and optimize the HIGEE rotatingoil purifier and other mechanical devices which was widelyused in resources and environmental systems In order tocertificate the numerical results corresponding experimentsneed to be investigated in the future work
Acknowledgments
This research was funded by the Natural Science Founda-tions of China (no 51075007) National High-tech RampD(863) Program (no 2012AA091103) and The Importationand Development of High-Caliber Talents Project of BeijingMunicipal Institutions (CITampTCD 20130316)
References
[1] Z X Xia Contamination Control of Hydraulic System ChinaMachine Press Beijing 1992
[2] C Ramshaw ldquolsquoHiGeersquo distillation-An example of process inten-sificationrdquo Chemical Engineering Science vol 389 pp 13ndash141983
[3] M Keyvani and N C Gardner ldquoOperating characteristics ofrotating bedsrdquo Chemical Engineering Progress vol 85 no 9 pp48ndash52 1989
[4] H S Liu C C Lin S C Wu and H W Hsu ldquoCharacteristicsof a rotating packed bedrdquo Industrial and Engineering ChemistryResearch vol 35 no 10 pp 3590ndash3596 1996
[5] D P RaoA Bhowal andP SGoswami ldquoProcess intensificationin rotating packed beds (HIGee) an Appraisalrdquo Industrial andEngineering Chemistry Research vol 43 no 4 pp 1150ndash11622004
[6] X Li Y Liu Z Li and X Wang ldquoContinues distillation exper-iment with rotating packed bedrdquo Chinese Journal of ChemicalEngineering vol 16 no 4 pp 656ndash662 2008
[7] H Ji S L Nie H M Sun and X H Tang ldquoResearch on on-linepurification of hydraulic oil based on high gravity technologyrdquoChinese Hydraulics amp Pneumatics no 11 pp 1ndash6 2011
[8] C Zheng K Guo Y Feng C Yang and N C GardnerldquoPressure drop of centripetal gas flow through rotating bedsrdquoIndustrial and Engineering Chemistry Research vol 39 no 3 pp829ndash834 2000
[9] A Basic and M P Dudukovic ldquoLiquid holdup in rotatingpacked beds examination of the film flow assumptionrdquo AIChEJournal vol 41 no 2 pp 301ndash316 1995
[10] M J Lockett ldquoFlooding of rotating structured packing and itsapplication to conventional packed columnsrdquo Trans IChemEvol 73 pp 379ndash384 1995
[11] K Guo F Guo Y Feng J Chen C Zheng and N C GardnerldquoSynchronous visual and RTD study on liquid flow in rotatingpacked-bed contractorrdquo Chemical Engineering Science vol 55no 9 pp 1699ndash1706 2000
[12] C Ramshaw and R H Mallinson ldquoMass transfer processrdquo USPatent 4 vol 283 no 255 1981
[13] H H Tung and R S H Mah ldquoModeling liquid mass tranferin HIGee separtion processrdquo Chemical Engineering Communi-cations vol 39 no 1ndash6 pp 147ndash153 1985
[14] S Munjal M P Dudukovc and P Ramachandran ldquoMass-transfer in rotating packed beds-I Development of gas-liquidand liquid-solidmass-transfer correlationsrdquoChemical Engineer-ing Science vol 44 no 10 pp 2245ndash2256 1989
[15] S Munjal M P Dudukovic and P Ramachandran ldquoMass-transfer in rotating packed beds-II Experimental results andcomparisonwith theory and gravity flowrdquoChemical EngineeringScience vol 44 no 10 pp 2257ndash2268 1989
[16] M Kumar and N C Gardner ldquoOperating characteristics ofrotating bedsrdquo Chemical Engineering Science vol 85 no 9 pp48ndash52 1989
[17] M P Kumar andD P Rao ldquoStudies on a high-gravity gas-liquidcontactorrdquo Industrial Engineering Chemistry Research vol 29no 5 pp 917ndash920 1990
[18] S P Singh J H Wilson R M Counce et al ldquoRemoval ofvolatile organic compounds from groundwater using a rotaryair stripperrdquo Industrial and Engineering Chemistry Research vol31 no 2 pp 574ndash580 1992
Mathematical Problems in Engineering 9
[19] Y H Chen C Y Chang W L Su et al ldquoModeling ozonecontacting process in a rotating packed bedrdquo Industrial andEngineering Chemistry Research vol 43 no 1 pp 228ndash2362004
[20] Y S Chen C C Lin and H S Liu ldquoMass tranfer in a rotationgpacked bed with viscous newtonian and non-newtonian fluidsrdquoIndustrial Engineering Chemistry Research vol 44 no 4 pp1043ndash1051 2005
[21] Y S Chen C C Lin and H S Liu ldquoMass tranfer in a rotationgpacked bed with viscous radii of the bedrdquo Industrial EngineeringChemistry Research vol 44 no 20 pp 7868ndash7875 2005
[22] J R Burns and C Ramshaw ldquoProcess intensification visualstudy of liquid maldistribution in rotating packed bedsrdquo Chem-ical Engineering Science vol 51 no 8 pp 1347ndash1352 1996
[23] L J Guo Two-Phase and multiPhase Hydrodynamics XirsquoanJiaotong University Press Xirsquoan China 2002
[24] X Y Kong Advanced Mechanics of Fluid Flow in Porous MediaChinese Science andTechnologyUniversity PressHefei China2010
[25] L S ChengAdvancedMechanics of Fluid Flow in PorousMediaPetroleum Industry Press Beijng China 2010
[26] L Fan RTHaiW XWang Z Lu andZM Yang ldquoApplicationof computational fluid dynamic to model the hydraulic perfor-mance of subsurface flow wetlandsrdquo Journal of EnvironmentalSciences vol 20 no 12 pp 1415ndash1422 2008
[27] Z Wen L C Shi and Y R Ren The Flent ComputationalDynamics Application Guide Tsinghua University Press Bei-jing China 2009
[28] J C Sheng Hydraulic Fluid Mechanics Mechanical IndustryPress Beijing China 1980
[29] Y Yu J M Zhang and L T Jiang Fluent Introductory andAdvanced Course Beijing Institute of Technology Press BeijingChina 2011
Figure 8 Graphs of the volume fraction of oil in the outlet with different configurations
100 but the fraction of oil in the water outlet can also beabout less than 95
Simulation results show that the simulation results indi-cate that the separating efficiency of HIGEE rotating oilpurifier is greatly affected by the configuration ConfigurationD is the best configuration In Configuration D the volumefraction of oil in the oil outlet can be up to 100 and it isentirely 100 but the fraction of oil in the water outlet canalso be about less than 95
33 Discussion Simulation results show that because of dif-ferent densities when the oil from preliminary purificationgoes through the HIGEE field the oil-which has a low
density outflows from the oil outlet in the middle where it isnear the rotation axis while water which has a high densityoutflows from the water outlet is in the edge where it is faraway from the oil outlet
Applying the inlet pressure is for applying an inlet velocityto the oil from preliminary purification When the inletpressure is small which can increase the residence time ofthe oil-water mixture therefore the fluid from preliminarypurification can make a good contact with hydrophilicmaterial in the RPB to get better separation efficiency Theseparation efficiency of HIGEE rotating oil purifier increaseswith the decreasing of inlet pressure in particular when theinlet pressure is 0002MPa the separation efficiency is thebest However a small pressure is not the best choice for the
8 Mathematical Problems in Engineering
inlet pressureTheworking hours will last long when the inletvelocity is very small
The separating efficiency of HIGEE rotating oil purifier isgreatly affected by the configurations Configuration D is thebest configuration The layout of liquid inlet oil outlet andwater outlet of the RPB significantly affected the separatingefficiencyWhen the liquid inlet is placed in the outside of thelower surface of RPB oil outlet is placed in the upper surfacewhere it is near the rotation axis and water outlet is placedin the middle of the side of the RPB where it is far awayfrom the oil outlet the corresponding separating efficiencywas the best In Configuration D the volume fraction of oil inthe oil outlet can be up to 100 and it is entirely 100 butthe fraction of oil in the water outlet can also be about lessthan 95 which is better than other configurations
4 Conclusions
Unlike previous experimental research numerical simulationis employed in this paper to analyze the flow characteristicsinside the RPB and related conclusions are got
(1) The oil-water two-phase flow is simulated based onthe 3D model of the RPB which is established inGambit
(2) The operating conditions on the hydraulic perfor-mance of the RPB are investigated Inlet pressure hasbig effect on the separation efficiency of HIGEE rotat-ing oil purifier The separation efficiency of HIGEErotating oil purifier increases with the decreasing ofinlet pressure in particular when the inlet pressure is0002MPa the separation efficiency is the best
(3) Simulation results also show that the separatingefficiency of HIGEE rotating oil purifier is greatlyaffected by the configuration especially the layout ofliquid inlet oil outlet and water outlet in the RPBWhen the liquid inlet is placed in the outside of thelower surface of RPB oil outlet is placed in the uppersurface where it is near to the rotation axis andwater outlet is placed in the middle of the side ofthe RPB which it is far away from the oil outlet thecorresponding separating efficiency is the best
Compared with theoretical analysis and experimentalresearch numerical simulation has provided an easy andeffective method to design and optimize the HIGEE rotatingoil purifier and other mechanical devices which was widelyused in resources and environmental systems In order tocertificate the numerical results corresponding experimentsneed to be investigated in the future work
Acknowledgments
This research was funded by the Natural Science Founda-tions of China (no 51075007) National High-tech RampD(863) Program (no 2012AA091103) and The Importationand Development of High-Caliber Talents Project of BeijingMunicipal Institutions (CITampTCD 20130316)
References
[1] Z X Xia Contamination Control of Hydraulic System ChinaMachine Press Beijing 1992
[2] C Ramshaw ldquolsquoHiGeersquo distillation-An example of process inten-sificationrdquo Chemical Engineering Science vol 389 pp 13ndash141983
[3] M Keyvani and N C Gardner ldquoOperating characteristics ofrotating bedsrdquo Chemical Engineering Progress vol 85 no 9 pp48ndash52 1989
[4] H S Liu C C Lin S C Wu and H W Hsu ldquoCharacteristicsof a rotating packed bedrdquo Industrial and Engineering ChemistryResearch vol 35 no 10 pp 3590ndash3596 1996
[5] D P RaoA Bhowal andP SGoswami ldquoProcess intensificationin rotating packed beds (HIGee) an Appraisalrdquo Industrial andEngineering Chemistry Research vol 43 no 4 pp 1150ndash11622004
[6] X Li Y Liu Z Li and X Wang ldquoContinues distillation exper-iment with rotating packed bedrdquo Chinese Journal of ChemicalEngineering vol 16 no 4 pp 656ndash662 2008
[7] H Ji S L Nie H M Sun and X H Tang ldquoResearch on on-linepurification of hydraulic oil based on high gravity technologyrdquoChinese Hydraulics amp Pneumatics no 11 pp 1ndash6 2011
[8] C Zheng K Guo Y Feng C Yang and N C GardnerldquoPressure drop of centripetal gas flow through rotating bedsrdquoIndustrial and Engineering Chemistry Research vol 39 no 3 pp829ndash834 2000
[9] A Basic and M P Dudukovic ldquoLiquid holdup in rotatingpacked beds examination of the film flow assumptionrdquo AIChEJournal vol 41 no 2 pp 301ndash316 1995
[10] M J Lockett ldquoFlooding of rotating structured packing and itsapplication to conventional packed columnsrdquo Trans IChemEvol 73 pp 379ndash384 1995
[11] K Guo F Guo Y Feng J Chen C Zheng and N C GardnerldquoSynchronous visual and RTD study on liquid flow in rotatingpacked-bed contractorrdquo Chemical Engineering Science vol 55no 9 pp 1699ndash1706 2000
[12] C Ramshaw and R H Mallinson ldquoMass transfer processrdquo USPatent 4 vol 283 no 255 1981
[13] H H Tung and R S H Mah ldquoModeling liquid mass tranferin HIGee separtion processrdquo Chemical Engineering Communi-cations vol 39 no 1ndash6 pp 147ndash153 1985
[14] S Munjal M P Dudukovc and P Ramachandran ldquoMass-transfer in rotating packed beds-I Development of gas-liquidand liquid-solidmass-transfer correlationsrdquoChemical Engineer-ing Science vol 44 no 10 pp 2245ndash2256 1989
[15] S Munjal M P Dudukovic and P Ramachandran ldquoMass-transfer in rotating packed beds-II Experimental results andcomparisonwith theory and gravity flowrdquoChemical EngineeringScience vol 44 no 10 pp 2257ndash2268 1989
[16] M Kumar and N C Gardner ldquoOperating characteristics ofrotating bedsrdquo Chemical Engineering Science vol 85 no 9 pp48ndash52 1989
[17] M P Kumar andD P Rao ldquoStudies on a high-gravity gas-liquidcontactorrdquo Industrial Engineering Chemistry Research vol 29no 5 pp 917ndash920 1990
[18] S P Singh J H Wilson R M Counce et al ldquoRemoval ofvolatile organic compounds from groundwater using a rotaryair stripperrdquo Industrial and Engineering Chemistry Research vol31 no 2 pp 574ndash580 1992
Mathematical Problems in Engineering 9
[19] Y H Chen C Y Chang W L Su et al ldquoModeling ozonecontacting process in a rotating packed bedrdquo Industrial andEngineering Chemistry Research vol 43 no 1 pp 228ndash2362004
[20] Y S Chen C C Lin and H S Liu ldquoMass tranfer in a rotationgpacked bed with viscous newtonian and non-newtonian fluidsrdquoIndustrial Engineering Chemistry Research vol 44 no 4 pp1043ndash1051 2005
[21] Y S Chen C C Lin and H S Liu ldquoMass tranfer in a rotationgpacked bed with viscous radii of the bedrdquo Industrial EngineeringChemistry Research vol 44 no 20 pp 7868ndash7875 2005
[22] J R Burns and C Ramshaw ldquoProcess intensification visualstudy of liquid maldistribution in rotating packed bedsrdquo Chem-ical Engineering Science vol 51 no 8 pp 1347ndash1352 1996
[23] L J Guo Two-Phase and multiPhase Hydrodynamics XirsquoanJiaotong University Press Xirsquoan China 2002
[24] X Y Kong Advanced Mechanics of Fluid Flow in Porous MediaChinese Science andTechnologyUniversity PressHefei China2010
[25] L S ChengAdvancedMechanics of Fluid Flow in PorousMediaPetroleum Industry Press Beijng China 2010
[26] L Fan RTHaiW XWang Z Lu andZM Yang ldquoApplicationof computational fluid dynamic to model the hydraulic perfor-mance of subsurface flow wetlandsrdquo Journal of EnvironmentalSciences vol 20 no 12 pp 1415ndash1422 2008
[27] Z Wen L C Shi and Y R Ren The Flent ComputationalDynamics Application Guide Tsinghua University Press Bei-jing China 2009
[28] J C Sheng Hydraulic Fluid Mechanics Mechanical IndustryPress Beijing China 1980
[29] Y Yu J M Zhang and L T Jiang Fluent Introductory andAdvanced Course Beijing Institute of Technology Press BeijingChina 2011
inlet pressureTheworking hours will last long when the inletvelocity is very small
The separating efficiency of HIGEE rotating oil purifier isgreatly affected by the configurations Configuration D is thebest configuration The layout of liquid inlet oil outlet andwater outlet of the RPB significantly affected the separatingefficiencyWhen the liquid inlet is placed in the outside of thelower surface of RPB oil outlet is placed in the upper surfacewhere it is near the rotation axis and water outlet is placedin the middle of the side of the RPB where it is far awayfrom the oil outlet the corresponding separating efficiencywas the best In Configuration D the volume fraction of oil inthe oil outlet can be up to 100 and it is entirely 100 butthe fraction of oil in the water outlet can also be about lessthan 95 which is better than other configurations
4 Conclusions
Unlike previous experimental research numerical simulationis employed in this paper to analyze the flow characteristicsinside the RPB and related conclusions are got
(1) The oil-water two-phase flow is simulated based onthe 3D model of the RPB which is established inGambit
(2) The operating conditions on the hydraulic perfor-mance of the RPB are investigated Inlet pressure hasbig effect on the separation efficiency of HIGEE rotat-ing oil purifier The separation efficiency of HIGEErotating oil purifier increases with the decreasing ofinlet pressure in particular when the inlet pressure is0002MPa the separation efficiency is the best
(3) Simulation results also show that the separatingefficiency of HIGEE rotating oil purifier is greatlyaffected by the configuration especially the layout ofliquid inlet oil outlet and water outlet in the RPBWhen the liquid inlet is placed in the outside of thelower surface of RPB oil outlet is placed in the uppersurface where it is near to the rotation axis andwater outlet is placed in the middle of the side ofthe RPB which it is far away from the oil outlet thecorresponding separating efficiency is the best
Compared with theoretical analysis and experimentalresearch numerical simulation has provided an easy andeffective method to design and optimize the HIGEE rotatingoil purifier and other mechanical devices which was widelyused in resources and environmental systems In order tocertificate the numerical results corresponding experimentsneed to be investigated in the future work
Acknowledgments
This research was funded by the Natural Science Founda-tions of China (no 51075007) National High-tech RampD(863) Program (no 2012AA091103) and The Importationand Development of High-Caliber Talents Project of BeijingMunicipal Institutions (CITampTCD 20130316)
References
[1] Z X Xia Contamination Control of Hydraulic System ChinaMachine Press Beijing 1992
[2] C Ramshaw ldquolsquoHiGeersquo distillation-An example of process inten-sificationrdquo Chemical Engineering Science vol 389 pp 13ndash141983
[3] M Keyvani and N C Gardner ldquoOperating characteristics ofrotating bedsrdquo Chemical Engineering Progress vol 85 no 9 pp48ndash52 1989
[4] H S Liu C C Lin S C Wu and H W Hsu ldquoCharacteristicsof a rotating packed bedrdquo Industrial and Engineering ChemistryResearch vol 35 no 10 pp 3590ndash3596 1996
[5] D P RaoA Bhowal andP SGoswami ldquoProcess intensificationin rotating packed beds (HIGee) an Appraisalrdquo Industrial andEngineering Chemistry Research vol 43 no 4 pp 1150ndash11622004
[6] X Li Y Liu Z Li and X Wang ldquoContinues distillation exper-iment with rotating packed bedrdquo Chinese Journal of ChemicalEngineering vol 16 no 4 pp 656ndash662 2008
[7] H Ji S L Nie H M Sun and X H Tang ldquoResearch on on-linepurification of hydraulic oil based on high gravity technologyrdquoChinese Hydraulics amp Pneumatics no 11 pp 1ndash6 2011
[8] C Zheng K Guo Y Feng C Yang and N C GardnerldquoPressure drop of centripetal gas flow through rotating bedsrdquoIndustrial and Engineering Chemistry Research vol 39 no 3 pp829ndash834 2000
[9] A Basic and M P Dudukovic ldquoLiquid holdup in rotatingpacked beds examination of the film flow assumptionrdquo AIChEJournal vol 41 no 2 pp 301ndash316 1995
[10] M J Lockett ldquoFlooding of rotating structured packing and itsapplication to conventional packed columnsrdquo Trans IChemEvol 73 pp 379ndash384 1995
[11] K Guo F Guo Y Feng J Chen C Zheng and N C GardnerldquoSynchronous visual and RTD study on liquid flow in rotatingpacked-bed contractorrdquo Chemical Engineering Science vol 55no 9 pp 1699ndash1706 2000
[12] C Ramshaw and R H Mallinson ldquoMass transfer processrdquo USPatent 4 vol 283 no 255 1981
[13] H H Tung and R S H Mah ldquoModeling liquid mass tranferin HIGee separtion processrdquo Chemical Engineering Communi-cations vol 39 no 1ndash6 pp 147ndash153 1985
[14] S Munjal M P Dudukovc and P Ramachandran ldquoMass-transfer in rotating packed beds-I Development of gas-liquidand liquid-solidmass-transfer correlationsrdquoChemical Engineer-ing Science vol 44 no 10 pp 2245ndash2256 1989
[15] S Munjal M P Dudukovic and P Ramachandran ldquoMass-transfer in rotating packed beds-II Experimental results andcomparisonwith theory and gravity flowrdquoChemical EngineeringScience vol 44 no 10 pp 2257ndash2268 1989
[16] M Kumar and N C Gardner ldquoOperating characteristics ofrotating bedsrdquo Chemical Engineering Science vol 85 no 9 pp48ndash52 1989
[17] M P Kumar andD P Rao ldquoStudies on a high-gravity gas-liquidcontactorrdquo Industrial Engineering Chemistry Research vol 29no 5 pp 917ndash920 1990
[18] S P Singh J H Wilson R M Counce et al ldquoRemoval ofvolatile organic compounds from groundwater using a rotaryair stripperrdquo Industrial and Engineering Chemistry Research vol31 no 2 pp 574ndash580 1992
Mathematical Problems in Engineering 9
[19] Y H Chen C Y Chang W L Su et al ldquoModeling ozonecontacting process in a rotating packed bedrdquo Industrial andEngineering Chemistry Research vol 43 no 1 pp 228ndash2362004
[20] Y S Chen C C Lin and H S Liu ldquoMass tranfer in a rotationgpacked bed with viscous newtonian and non-newtonian fluidsrdquoIndustrial Engineering Chemistry Research vol 44 no 4 pp1043ndash1051 2005
[21] Y S Chen C C Lin and H S Liu ldquoMass tranfer in a rotationgpacked bed with viscous radii of the bedrdquo Industrial EngineeringChemistry Research vol 44 no 20 pp 7868ndash7875 2005
[22] J R Burns and C Ramshaw ldquoProcess intensification visualstudy of liquid maldistribution in rotating packed bedsrdquo Chem-ical Engineering Science vol 51 no 8 pp 1347ndash1352 1996
[23] L J Guo Two-Phase and multiPhase Hydrodynamics XirsquoanJiaotong University Press Xirsquoan China 2002
[24] X Y Kong Advanced Mechanics of Fluid Flow in Porous MediaChinese Science andTechnologyUniversity PressHefei China2010
[25] L S ChengAdvancedMechanics of Fluid Flow in PorousMediaPetroleum Industry Press Beijng China 2010
[26] L Fan RTHaiW XWang Z Lu andZM Yang ldquoApplicationof computational fluid dynamic to model the hydraulic perfor-mance of subsurface flow wetlandsrdquo Journal of EnvironmentalSciences vol 20 no 12 pp 1415ndash1422 2008
[27] Z Wen L C Shi and Y R Ren The Flent ComputationalDynamics Application Guide Tsinghua University Press Bei-jing China 2009
[28] J C Sheng Hydraulic Fluid Mechanics Mechanical IndustryPress Beijing China 1980
[29] Y Yu J M Zhang and L T Jiang Fluent Introductory andAdvanced Course Beijing Institute of Technology Press BeijingChina 2011
[19] Y H Chen C Y Chang W L Su et al ldquoModeling ozonecontacting process in a rotating packed bedrdquo Industrial andEngineering Chemistry Research vol 43 no 1 pp 228ndash2362004
[20] Y S Chen C C Lin and H S Liu ldquoMass tranfer in a rotationgpacked bed with viscous newtonian and non-newtonian fluidsrdquoIndustrial Engineering Chemistry Research vol 44 no 4 pp1043ndash1051 2005
[21] Y S Chen C C Lin and H S Liu ldquoMass tranfer in a rotationgpacked bed with viscous radii of the bedrdquo Industrial EngineeringChemistry Research vol 44 no 20 pp 7868ndash7875 2005
[22] J R Burns and C Ramshaw ldquoProcess intensification visualstudy of liquid maldistribution in rotating packed bedsrdquo Chem-ical Engineering Science vol 51 no 8 pp 1347ndash1352 1996
[23] L J Guo Two-Phase and multiPhase Hydrodynamics XirsquoanJiaotong University Press Xirsquoan China 2002
[24] X Y Kong Advanced Mechanics of Fluid Flow in Porous MediaChinese Science andTechnologyUniversity PressHefei China2010
[25] L S ChengAdvancedMechanics of Fluid Flow in PorousMediaPetroleum Industry Press Beijng China 2010
[26] L Fan RTHaiW XWang Z Lu andZM Yang ldquoApplicationof computational fluid dynamic to model the hydraulic perfor-mance of subsurface flow wetlandsrdquo Journal of EnvironmentalSciences vol 20 no 12 pp 1415ndash1422 2008
[27] Z Wen L C Shi and Y R Ren The Flent ComputationalDynamics Application Guide Tsinghua University Press Bei-jing China 2009
[28] J C Sheng Hydraulic Fluid Mechanics Mechanical IndustryPress Beijing China 1980
[29] Y Yu J M Zhang and L T Jiang Fluent Introductory andAdvanced Course Beijing Institute of Technology Press BeijingChina 2011
