Removal by Inertial Impaction Uses the energy from the fluid Removal of larger particle size, 10 micron and above Used for bulk removal. Removal by Direct Impaction Uses Filter Media with close mesh size (and inertial device) Removal of fine particle size, typically 1 micron and above - PowerPoint PPT Presentation
Separation Vs Separation Vs Filtration Filtration • Removal by Inertial Removal by Inertial Impaction Impaction • Uses the energy from Uses the energy from the fluid the fluid • Removal of larger Removal of larger particle size, 10 particle size, 10 micron and above micron and above • Used for bulk removal Used for bulk removal • Removal by Direct Removal by Direct Impaction Impaction • Uses Filter Media with Uses Filter Media with close mesh size (and close mesh size (and inertial device) inertial device) • Removal of fine Removal of fine particle size, particle size, typically 1 micron and typically 1 micron and above above • Used for both bulk & Used for both bulk & aerosol removal aerosol removal
Transcript
Separation Vs FiltrationSeparation Vs Filtration
• Removal by Inertial ImpactionRemoval by Inertial Impaction
• Uses the energy from the fluidUses the energy from the fluid
• Removal of larger particle size, Removal of larger particle size, 10 micron and above10 micron and above
• Used for bulk removalUsed for bulk removal
• Removal by Direct ImpactionRemoval by Direct Impaction
• Uses Filter Media with close mesh Uses Filter Media with close mesh
• Removal of fine particle size, Removal of fine particle size,
typically 1 micron and abovetypically 1 micron and above
• Used for both bulk & aerosol Used for both bulk & aerosol removalremoval
Factors Influencing Gas Factors Influencing Gas Filtration SelectionFiltration Selection
• Removal Efficiency, location of the filter systemRemoval Efficiency, location of the filter system
• Properties of Gas, flow rateProperties of Gas, flow rate
• Type and quantity of Particle to be removed and its propertiesType and quantity of Particle to be removed and its properties
• Operating pressure & temperatureOperating pressure & temperature
• Type of controls requiredType of controls required
• Pressure drop allowed & Turn-down RatioPressure drop allowed & Turn-down Ratio
• Material specificationMaterial specification
Information RequiredInformation Required
• Location & Removal EfficiencyLocation & Removal Efficiency• Type & Property of Contaminant – Oil in particularType & Property of Contaminant – Oil in particular• Gas Property or MW or Sp. GravityGas Property or MW or Sp. Gravity• Flow Rate – Min / MaxFlow Rate – Min / Max• Operating Pressure – Min / MaxOperating Pressure – Min / Max• Operating Temperature – Min / MaxOperating Temperature – Min / Max• Allowed pressure dropAllowed pressure drop• Liquid Holding time or capacityLiquid Holding time or capacity• Controls requiredControls required• Configuration – Horizontal, Vertical, In-lineConfiguration – Horizontal, Vertical, In-line• Special material, if any, requiredSpecial material, if any, required
Flow RateFlow Rate
• Flow rates converted to ACFM or ACFS.Flow rates converted to ACFM or ACFS.
• At low pressure ACFM will be higher than at High Pressure.At low pressure ACFM will be higher than at High Pressure.
• At high temperature ACFM is higher than at low temperature .At high temperature ACFM is higher than at low temperature .
• SCFM and LB/Hr are independent of pressure and temperature SCFM and LB/Hr are independent of pressure and temperature while ACFM is sensitive to these.while ACFM is sensitive to these.
Operating PressureOperating Pressure
• Low pressure increases the ACFM.Low pressure increases the ACFM.
• High pressure increases cost of separator.High pressure increases cost of separator.
• High pressure increases density resulting in decrease in High pressure increases density resulting in decrease in density difference between gas & liquid and separation density difference between gas & liquid and separation becomes more difficult.becomes more difficult.
• Drop in allowable shear force and therefore reduced Drop in allowable shear force and therefore reduced velocity. (velocity. (VV22))
• Mass flow rate is independent of pressure for a given Mass flow rate is independent of pressure for a given SCFM.SCFM.
Operating TemperatureOperating Temperature
• High Temperature increases ACFM.High Temperature increases ACFM.
• Influences filter element selection.Influences filter element selection.
• Influences material selection.Influences material selection.
• Influences control instrument selection.Influences control instrument selection.
• Mass flow rate is independent of temperature for a given Mass flow rate is independent of temperature for a given SCFM.SCFM.
• MW decides specific gravity.MW decides specific gravity.
• Specific gravity influences density based on operating Specific gravity influences density based on operating pressure and temperature.pressure and temperature.
• Density influences velocity through the device and the size of Density influences velocity through the device and the size of the Separator.the Separator.
• ACFM is independent of MWACFM is independent of MW for a given SCFM.for a given SCFM.
Type of ContaminantType of Contaminant
• Solids, solids and liquids, liquids. Solids, solids and liquids, liquids. • Nature of liquid and volume flow rate, Liquid/Gas ratio,Nature of liquid and volume flow rate, Liquid/Gas ratio,• Density of liquid.Density of liquid.• Viscosity of the liquid, if high drainage would be a problem, Viscosity of the liquid, if high drainage would be a problem,
may require a mesh pad foe vane packs.may require a mesh pad foe vane packs.• Surface tension, if shear stress drops, re-entrainment would Surface tension, if shear stress drops, re-entrainment would
occur.occur.• Above factors dictate size, type of device and controls required.Above factors dictate size, type of device and controls required.
Removal EfficiencyRemoval Efficiency
• Inertial Separators typically can remove only 10 micron and above. Inertial Separators typically can remove only 10 micron and above.
• Vane will not guarantee removal of solids.Vane will not guarantee removal of solids.
• If heavy oil is present may require mesh pad addition.If heavy oil is present may require mesh pad addition.
• Re-entrainment occurs at high gas velocity, dictates size of filter Re-entrainment occurs at high gas velocity, dictates size of filter vessel.vessel.
• Influences filter element selection .Influences filter element selection .
• CompressibilityCompressibility Factor, Z, corrects the gas density for Factor, Z, corrects the gas density for deviations from the ideal gas law.deviations from the ideal gas law.
• Use client specified value or use TEMA or Chemical Use client specified value or use TEMA or Chemical Engineers Handbook.Engineers Handbook.
• Use 1 if details not known.Use 1 if details not known.
Design ConsiderationsDesign Considerations• Inlet velocity not to exceed Inlet velocity not to exceed VV22 = 4500, based on TEMA = 4500, based on TEMA
guidelines.guidelines.• Inlet to have a baffle to break the momentum and to protect Inlet to have a baffle to break the momentum and to protect
against slugs.against slugs.• If oil or other liquid contaminants expected, vane pack If oil or other liquid contaminants expected, vane pack
with/without mesh pad or multi-cyclone type device with/without mesh pad or multi-cyclone type device required.required.
• If vane is selected for first stage and if inlet is directly in If vane is selected for first stage and if inlet is directly in front, to use agglomerator .front, to use agglomerator .
• Holding capacity required.Holding capacity required.• Size of inlet/outlet to vessel size.Size of inlet/outlet to vessel size.
ENTER THE GAS COMPOSITION TO ARRIVE AT A MOLECULAR WEIGHT.ENTER THE LOWEST NORMAL OPERATING PRESSURE IN CELL F17.ENTER THE HIGHEST NORMAL OPERATING TEMPERATURE IN CELL F18DETERMINE COMPRESSIBILITY FACTOR FROM CHARTS/TABLES AND ENTER IN CELL C50.IN THE CASE OF FLOW SPECIFIED IN SCFM ENTER RATE IN CELL B20. ADJUST C21 TO = B21.IN THE CASE OF FLOW SPECIFIED IN LB/HR ENTER THE RATE IN CELL C22. ADJUST B20 TO = C20
Enter The Gas Composition Serving As The Design Basis:
NATIONAL FILTRATION SYSTEMS, INC. JOB OR QUOTE NO.INTERNAL DOCUMENT ONLY - THIS DOCUMENT IS NOT TO BE ISSUED DATEOUTSIDE THE COMPANY WITHOUT THE AUTHORIZATION OF AN ANALYSIS PERFORMED BY:OFFICER OF THE COMPANY. ANALYSIS APPROVED BY:ELEMENT ANALYZED (NFS PART NO.) X
V64 V94.3Q FLOW RATE, (SCFM) Flow Rate, SCFM 19,130 37,082 PO NORMAL OPERATING PRESSURE, (PSIG) NOTE 1 PO 260 260Mw Molecular Weight Mw 19.51 19.51TO NORMAL OPERATING TEMPERATURE, (°F) NOTE 2 TO 40 40QA ACFM = SCFM * 14.7 * (460° + TO)*Z / (PO + 14.7) * 520° Flow Rate, ACFM 984.32 1908.02Z Compressebility factor Z 1.00 1.00SG = MOLECULAR WEIGHT (MW) / 28.97 NOTE 3 Specific Gravity 0.67 0.67r DENSITY LBS. / FT3 = ((PO + 14.7)* Mw) / (Z*10.73* (TO + 460° F)) Density 1.05 1.05LBS / HR = QA * r * 60 Pounds Per Hour 61906 120000V VISCOSITY - (FROM CRANE TECHNICAL PAPER #410 PAGE A5) Viscosity (cp) 0.01 0.01
Radial Pleated Element DimensionsL EFFECTIVE LENGTH OF ELEMENT NOTE 4 Length (IN) 24.25 24.25Di INSIDE DIAMETER OF ELEMENT Di (IN) 11.00 11.00Ci ELEMENT INTERNAL CIRCUMFERENCE = p Di Ci (IN) 34.56 34.56Do OUTSIDE DIAMETER OF ELEMENT Do (IN) 15.5 15.5PL NO. OF PLEATS PER INCH OF CIRCUMFERENCE @ Di Pleats Per Inch 3.36 3.36PLT TOTAL NO. OF PLEATS = Ci * PL PLT 116.12 116.12Q1 QUANTITY OF ELEMENTS Quantity Of Elements 1 2AE PLEATED ELEMENT SURFACE AREA = ((L * (Do - Di)/2) * PLT) /144 Area Per Element (FT2) 44.00 44.00AET TOTAL ELEMENT SURFACE AREA = AE * Q1 Total Elemental Area (FT2) 44.00 88.00CAE CROSS SECTIONAL AREA OF ELEMENT = Do
2 * 0.7854 Cross Sectional Area Of Element (IN2) 188.69 188.69N NO. OF COLUMNS N 1.00 2.00CAET TOTAL CROSS SECTIONAL AREA OF ELEMENTS = CAE * N Total Cross Sectional Area (IN2) 188.69 377.38W = QA / AET (Face Velocity) Flow Rate Per Sq. Ft. Of Media 22.37 21.68ARP = 2piR(R+L)*.48 where R = 1/2Do Restriction Plate Surface Area - EA 5.19 5.19ARPT = ARP * N Restriction Plate Surface Area - TOT 5.19 10.39VRP = QA / ARPT (Restriction Velocity) Restriction Velocity 189.51 183.67
Gas Flow Hold Up Factor 8.47 8.47
Filter Housing DimensionsDiN INSIDE DIAMETER - NOZZLE PIPE Nozzle ID (IN) 7.875 9.5DiH INSIDE DIAMETER - VESSEL Housing ID (IN) 26.5 36CAN NOZZLE CROSS SECTIONAL AREA = DiN * 0.7854 Cross Sectional Area Of Nozzle (IN2) 48.71 70.88CAH HOUSING CROSS SECTIONAL AREA = DiH * 0.7854 Cross Sectional Area Of Housing (IN2) 551.55 1017.88
Velocity and Pressure Drop ResultsVi = (QA / DiN) * 144 Inlet Velocity (FPM) 2910.08 3876.21Vc = QA / (CAH - CAET) * 144 Channel Velocity (FPM) 390.63 428.97DP1 PRESSURE DROP DUE TO ENTRANCE AND EXIT LOSSES = Entrance / Exit Pressure Drop (PSI) 0.29 0.52DP2 PRESSURE DROP DUE TO ELEMENT RESTRICTION = Media Pressure Drop (PSI) 0.12 0.12DPT = DP1 + DP2 Total Pressure Drop (PSI) 0.41 0.64
