Production of LDPE

8/11/2019 Production of LDPE

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Introduction 0

INTRODUCTION ............................................................................................................... .......... 2

POLYETHYLENE:.............................................................................................................................2

GENERLDE!CRIPTION:................................................................................................................"

HI!TORYO#LO$DEN!ITYPOLYETHYLENE %LDPE&:....................................................................'TYPICLPPLICTION!:................................................................................................. .............. 11

LI(ITTION!O# LDPE:...............................................................................................................1"

PROCE!!!ELECTIONO#LDPEINTU)ULRRECTOR:...............................................................1*

!EPRTION!TEP!O#HIGH+PRE!!UREPROCE!!E!:...................................................................1,

PROCE!!INGO#POLYETHYLENE:................................................................................................ 1,

MATERIAL BALANCE......................................................................................................... 1-

CRO!!TU)ULRRECTOR:........................................................................................................1-

CRO!!HIGHPRE!!URE!EPRTOR:.........................................................................................1-

CRO!!LO$PRE!!URE!EPRTOR:.......................................................................................... 1-CRO!!THEDRYER...................................................................................................... ...............1

CO(PRE!!OR DE!IGN ................................................................................................ .......... . 21

INTRODUCTION:............................................................................................................................21

GENERLCON!IDERTION#ORNYTYPEO#CO(PRE!!OR#LO$CONDITION!:......................21

CO(PRE!!OR CL!!I#ICTION CHRT.............................................................................2*

!ELECTION O# CO(PRE!!OR...............................................................................................2'

RECIPROCTING CO(PRE!!OR............................................................................................ 2,

RECIPROCTING CO(PRE!!OR !PECI#ICTION!..........................................................2

DE!IGN PROCEDURE............................................................................................................... "1INTERCOOLER DE!IGN..........................................................................................................."-

!ELECTION GUIDE TO HET E/CHNGER TYPE!...........................................................*0

!HELL ND TU)E HET E/CHNGER.................................................................................*1

CL!!I#ICTIONO#!HELLNDTU)EHETE/CHNGER!...................................................... ..*2

DE!IGNPROCEDURE#OR!HELL+ND+TU)EHETE/CHNGER!........................... .......... .........*"

TU)E !IDE CLCULTION!:..................................................................................................*,

!HELL !IDE CLCULTION!:................................................................................................*

)UNDLEDI D) DO3% NO. O#TU)E!451&3%14N1&.................................................*

D) 2-,.-((.......................................................................................................................... *-

D) 0.2(............................................................................................................................ .... *-

!HELLCLERNCE 11.0((..................................................................................*-

IN!IDEDI(ETERO#!HELL D! )UNDLEDI6!HELLCLERNCE.....................................*-IN!IDEDI(ETERO#!HELL D! 2-,.- 6 11.0 2.-((..............................................*-

PRE!!URE DROP TU)E !IDE:.................................................................................................*

#RICTION#CTOR7LUEONTU)E!IDE8# 0.002...............................................................*

PRE!!URE DROP !HELL !IDE:..............................................................................................'0

RE ''2-....................................................................................................................................'0

!PECI#ICTION !HEET #OR INTER COOLER....................................................................'0

0


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Introduction 1

RECTOR DE!IGN ....................................................................................................... ............ '"

DE7ELOP(ENT O# CHE(ICL RECTION RTE E/PRE!!ION!:...............................'*

RECTOR PRINCIPLE!.............................................................................................................'*

RECTORTYPE!...................................................................................................................... ..... ''

!PCE

7ELOCITY

ND

!PCE

TI(E

..............................................................................................''CHIN+GRO$TH POLY(ERI9TION..................................................................................''

5INETIC!:.....................................................................................................................................'

DETER(ININGTHE7OLU(EO#THERECTOR:..........................................................................'-

7LUE!O#RTECON!TNT!:....................................................................................................'

!ELECTINGTHE(ONO(ERCON7ER!ION:.................................................................................. '

CLCULTINGTHE7OLU(EO#THERECTOR:..........................................................................,0

EUTIONO#(ONO(ERCON7ER!ION:.....................................................................................,0

7OLU(E...................................................................................................................................... ,1

RE!ULT:........................................................................................................................................,1

(ODELINGND!I(ULTION#ORTHE(ULTIIN8ECTIONO#THEINITITOR............................,2

!!U(PTION!:............................................................................................................................. ,"

OPTI(L CONTROL O# THE RECTOR ............................................................................ .. ,'

OPTI(LCONTROLO)8ECTI7E:..................................................................................................,'

PREHEATING IN THE TUBULAR REACTOR....................................................... .... ,

DE!IGN:........................................................................................................................................,

#OR PIPE !IDE:..........................................................................................................................0

#OR NNULU!:...........................................................................................................................1

RECTIONNDCOOLING9ONE:..................................................................................................."

#OR PIPE !IDE...........................................................................................................................'#OR NNULU!:...........................................................................................................................,

PRE!!UREDROP#ORPIPE!IDE:.................................................................................................. -

DRU(! .................................................................................................................... ................... -0

GENERL:.....................................................................................................................................-0

7POR+LIUID!EPRTION.........................................................................................................-0

LIUID!URGE..............................................................................................................................-1

OPERTINGCONDITION!:.............................................................................................................-1

LIUID+LIUID!ETTLING........................................................................................................ .... -1

(ECHNICLCON#IGURTIONO#DRU(:..................................................................................-1

HIGH PRESSURE SEPARATOR................................................................................. .... -,

COOLER#TERHIGH+PRE!!URE!EPRTOR............................................................. .......... ........-

CHPTER 2 ..................................................................................................................... .......... . -

1


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Introduction 2

HETLOD:................................................................................................................................. -

LO$ PRE!!URE !EPRTOR ................................................................................................ 1

COOLER#TERLO$PRE!!URE!EPRTOR:.............................................................................. "

)UNDLEDI D) DO3% NO. O#TU)E!451&3%14N1&.................................................-D) 2-,.-((.......................................................................................................................... -

D) 0.2(............................................................................................................................ .... -

!HELLCLERNCE 11.0((..................................................................................-

IN!IDEDI(ETERO#!HELL D! )UNDLEDI6!HELLCLERNCE.....................................

IN!IDEDI(ETERO#!HELL D! 2-,.- 6 11.0 2.-((..............................................

#RICTION#CTOR7LUEONTU)E!IDE8# 0.00"'.............................................................101

RE -1*-.'-...............................................................................................................................102

!PECI#ICTION!HEET#ORCOOLER#TERLO$PRE!!URE!EPRTOR.................................10"

DRYING OPERTION:.............................................................................................................. 10*

CL!!I#ICTIONO#DRYER!)!EDONPHY!ICL#OR(O##EED:...........................................10'

CL!!I#ICTIONO#DRYER!)Y!CLEO#PRODUCTION............................................................10'

CL!!I#ICTIONO#DRYER!)Y!UIT)ILITY#OR!PECIL#ETURE!................. .....................10,!ELECTION O# DRYER:..........................................................................................................10,

!PECI#ICTION!HEETO#DRYER............................................................................................ ..11

#CTOR! ##ECTING CHOICE O# PU(P:........................................................................11

CHRCTERI!TIC! O# THE GER PU(P:........................................................................122

INSTRUMENTATION & CONTROL.................................................................. .......... 12*

TE(PERTURE (E!URE(ENT ND CONTROL...........................................................12'

#LO$ (E!URE(ENT ND CONTROL.............................................................................12'

HAZOP STUDY.................................................................................................................... 1"0

H9RDNDOPER)ILITY!TUDY%H9OP&:............................................................ ................1"0

!TEP! CONDUCTED IN H9OP !TUDY:.............................................................................1"1

ECONO(IC!O#HIGH+PRE!!UREPROCE!!E!:..........................................................................1"-

COST ESTIMATION.................................................................................................... ...... 1*1

#I/EDCPITLIN7E!T(ENT:............................................................................................... ....1*2

TYPE! O# CPITL CO!T E!TI(TE!...............................................................................1*"

CO!T INDE/E!.........................................................................................................................1**

CO!TE!TI(TIONO#CO(PRE!!OR..........................................................................................1*'

CO!TE!TI(TIONO#DOU)LEPIPEHETE/CHNGER............................................................1*,

CO!TE!TI(TIONO#HIGHPRE!!URE!EPRTOR..................................................... ..............1*,

CO!TE!TI(TIONO#LO$PRE!!URE!EPRTOR:...................................................................1*

!HELLNDTU)EINTERCOOLER%#ORCO(PERE!!OR&............................................... ...............1*

!HELLNDTU)EHETE/CHNGER% INTERCOOLERTERHIGHPRE!!URE!EPRTOR:....1*

!HELLNDTU)EHETE/CHNGER% INTERCOOLERTERLO$PRE!!URE!EPRTOR:......1*-

CO!TO#ROTRYDRYER:...........................................................................................................1*-

2


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Introduction 3

E!TI(TION O# TOTL CPITL IN7E!T(ENT DIRECTCO!T%R!&.........................................1*-

REFRENCES.......................................................................................................................... 1'*

3


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Introduction 2

INTRODUCTION

Polyethylene:

Polyethyleneor polyethyleneis a commodity thermoplastic heavily used in

consumer products (over 60M tons are produced worldwide every year). Its name

originates from the monomer ethene used to create the polymer. In the polymer industry

the name is sometimes shortened to PE similar to how other polymers li!e

polypropylene and polystyrene are shortened to "" and "# respectively. In the $nited

%ingdom the polymer is called polythene.

&he ethene molecule (!nown almost universally 'y its nonI$"* name ethylene) * 2+,

is *+2- *+2 &wo *+2connected 'y a dou'le 'ond thus

2
http://en.wikipedia.org/wiki/Image:Ethene.png


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Introduction 3

"olyethylene is created through polymeri/ation of ethene. It can 'e produced

through radical polymeri/ation anionic polymeri/ation and cationic polymeri/ation.

&his is 'ecause ethene does not have any su'stituent groups which influence the sta'ility

of the propagation head of the polymer.

ach of these methods results in a different type of polyethylene.

.

General Descripi!n:

semicrystalline (typically around 0) whitish semiopaue commodity

thermoplastic that is soft fle4i'le and tough even at low temperatures withoutstanding electrical properties 'ut poor temperature resistance. It also has very goodchemical resistance 'ut is prone to environmental stress crac!ing5 it has poor $resistance (unless modified) and poor 'arrier properties e4cept to water.

3
http://en.wikipedia.org/wiki/Image:Polyethene_monomer.png


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Introduction ,

Classification of polyethylenes:

"olyethylene is classified into several different categories 'ased mostly on its mechanical

properties. &he mechanical properties of " depend significantly on varia'les such as the

e4tent and type of 'ranching the crystal structure and the molecular weight.

$+M7" (ultra high molecular weight ")

+8" (high density ")

98" (low density ")

998" (linear low density " sometimes referred to as Medium 8ensity "

M8")

UHMWPEis polyethylene with a molecular weight num'ering in the millions usually

'etween 3.1 and .6: million. &he high molecular weight results in a very good pac!ing

of the chains into the crystal structure. &his results in a very tough material. $+M7" is

made through metallocene catalysis polymeri/ation.

HDPEhas a low degree of 'ranching and thus stronger intermolecular forces and

tensile strength. &he lac! of 'ranching is ensured 'y an appropriate choice of catalyst

(e.g. ;iegler


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Introduction

His!r" !# L!$ Densi" P!l"e%"lene LDPE'(

"olyethylene was first synthesi/ed 'y the =erman chemist +ans von "echmann

who prepared it 'y accident in 1>?> while heating dia/omethane. 7hen his colleagues

uge @am'erger and Ariedrich &schirner characteri/ed the white wa4y su'stance he had

created they recogni/ed that it contained long *+2 chains and termed itpolymethylene.

&he first industrially practical polyethylene synthesis was discovered (again 'y

accident) 'y ric Aawcett and Beginald =i'son at I*I *hemicals in 1?33. $pon applying

e4tremely high pressure (several hundred atmospheres) to a mi4ture of ethylene and

'en/aldehyde they again produced a white wa4y material. #ince the reaction had 'een

initiated 'y trace o4ygen contamination in their apparatus the e4periment was at first

difficult to reproduce. It was not until 1?3 that another I*I chemist Michael "errin

developed this accident into a reproduci'le highpressure synthesis for polyethylene that

'ecame the 'asis for industrial 98" production 'eginning in 1?3?.

&he story of polyethylene really starts in 1?32. @ritain along with the whole

industriali/ed world was in deep recession following the 7all #treet *rash of 1?2?. It

was difficult to find money for largescale research and yet something new was needed.

In I*I there was suggested a research program to loo! for new reactions under e4treme


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Introduction 6

pressure. Aifty different reactions were tried all without success 'ut one of the failures

resulted in the discovery of polyethylene through a remar!a'le series of coincidences.

Cne of the suggested mi4tures had included ethylene a very light gas prepared from

petroleum. &he reaction hoped for had not occurred 'ut instead there was a white wa4y

solid on the walls of the reaction vessel. nalysis showed that this must have formed

from the ethylene alone. In 1?3 the reaction was tried again without the other

component 'ut this time the vessel lea!ed5 nevertheless some more polyethylene was

o'tained. t this time I*I management made the very 'old decision to start a maDor

development programm on the 'asis of only > grams o'tained of the promising productE

#o they tightened up their procedures and as a result no polyethyleneE It was only after

months of wor! that they reali/ed that o4ygen had to 'e present in some form eitherfrom air lea!ing in or in the first e4periment indirectly from having reacted with the

other component of the original mi4ture. &hese two Fhappy accidentsF had allowed

polyethylene to 'e prod 9ow 8ensity "olyethylene (98") is a corrosionresistant

e4truded material that sustains low moisture permea'ility. It also has a relatively low

wor!ing temperature soft surface and low tensile strength.

Date Contri;utor

1>?> +ans van pechman

1?32 I*I

March 2, 1?32 I*I research

Ae' 1?36 I*I

#ep 1 1?3? I*I

1?,3 8upont

1??:

6


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Introduction :

Chei>tanceAcids - concentrated Good-Fair

Acids - dilute Good

Alcohols Good

Alkalis Good

Aromatic hydrocarbons Fair-Poor

Greases and Oils Good-Fair

Halogenated Hydrocarbons Fair-Poor

Halogens Fair-Poor

Ketones Good-Fair

E=ectrica= Propertie>

ielectric constant !"#H$ %&%-%&'(

ielectric strength ) k* mm-"+ %,

issipation factor ! "#H$ "-" . "-/

0urface resisti1ity ) Ohm2s3 + ""'

*olume resisti1ity ) Ohmcm + "

"(

-"

"4

:


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Introduction >

(echanica= Propertie>

5longation at break ) 6 + /Hardness - 7ock8ell /"-/9 0hore

;$od impact strength ) < m-"+ ="

>ensile modulus ) GPa + &"-&'

>ensile strength ) #Pa + (-%(

Ph?>ica= Propertie>

ensity ) g cm-'

+ &?%Flammability H@

imiting o.ygen inde. ) 6 + ",

7adiation resistance Fair

7efracti1e inde. "&("

7esistance to Bltra-1iolet Poor

ater absorption - o1er %/ hours ) 6

+

D&"(

>


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Introduction ?

Ther

Coefficient of thermal e.pansion) ."-9K-"+

"-%

Heat-deflection temperature -

&/(#Pa ) C +

(

o8er 8orking temperature ) C + -9

0pecific heat ) < K-"kg-"+ "?-%'

>hermal conducti1ity !%'C ) m-"

K-"+

&''

Bpper 8orking temperature ) C + (-?

?


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Introduction 10

Di@@erent propert? te>t> u>ed @or LDPE:

Polyethylene Properties

Property ASTM or ULTest

LDPE

Water Absorption (24hrs) (%) D-570


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Introduction 11

Benefits:

9ightweight

8esign ersatility

8imensional #ta'ility

4cellent lectrical "roperties

9ow *ost Aa'rications

Machina'le

Aorma'le

#ufficiently low water permea'ility.

7ipes *lean

Typical applications:

98" was introduced initially as a special purpose dielectric material of a particularly

value for high freuency insulation. fter #econd 7orld 7ar there was a dramatic

increase in the production of 98".


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Introduction 12

12


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Introduction 13

Li)iai!ns !# LDPE(

&he limitations of 98" include

&he low softening point.

&he opacity of material in 'ul!.

&he wa4 li!e appearance.

&he poor scratch resistance.

&he lac! of rigidity.

&he low tensile strength.

&he high gas permea'ility.

13


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Introduction 1,

Pr!cess seleci!n !# LDPE in *+*lar reac!r( It gives a more sta'le operation.


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Introduction 1

Aor producing low density polyethylene ethylene should 'e at least ??.? pure

containing trace amounts of ethane and methane.

Compressors:

*ompressing ethylene to high pressures needed for polymeri/ation is a maDor step of

overall process. 9arge positive displacement (piston) compressors are used .two step

compression system is normal in the first step ethylene at a relatively low pressure is

compressed to a'out 22 atm. In the second step of compression the ethylene feed is

com'ined with recycle ethylene and the mi4ture is compressed to reaction pressure 'y

the high pressure compressor.

&he temperature of ethylene must never e4ceed a'ove >0H* as the ethylene is

compressed. Ctherwise some polymeri/ation might occur. Aor this purpose intercoolers

are used after each stage.

Tubular Reactor:

thylene and dissolved initiator (o4ygen) enter the reactor tu'e at high pressures.

ach reactor consists of three /ones the first for preheating /one the second for reaction

and the third for cooling /one. +eat transfer media for heating and cooling /ones are

steam and water respectively.

fter the ethylene containing the initiator has 'een sufficiently heated conversion

starts and e4othermic heat of reaction causes an additional increase in temperature.

4othermic heat of reaction of 100 !DGmol has to 'e #uccessfully dissipated otherwise

there will 'ean increase in temperature of 121,H*.+eat transfer resistances are high in

the tu'ular reactor 'ecause of very thic! walls reuired to withstand the high pressures.

Cne way of removing the heat of reaction is to heat the incoming cool ethylene with

the outgoing mi4ture. &emperature must never rise a'ove 2,0H*. Multiple inDection of

initiator is used in order to increase the degree of conversion.

1


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Introduction 16

Separai!n seps !# %i,%-press*re pr!cesses(

fter leaving the reactor the mi4ture of ethylene and polyethylene enters into the

high pressure separator which operates at a'out 166 atm .the pressure is reduced with the

help of pressure reducing valve. &he efficiency of the high pressure separator is ?.&he

ethylene is flashed immediately as the pressure is reduced. &he rate of flashing must 'e

sufficiently low to avoid e4cessive foaming .#tarting with a single phase of ethylene and

polyethylene a polyethylene JprecipitateK is formed as flashing starts. s more ethylene

flashes the precipitated granules agglomerate to form a continuous polyethylene liuid.

&he remaining ethylene is separated in low pressure separator which operates at

atmospheric pressure. &he recovered ethylene is cooled with the help of coolers and

recycled.

Pr!cessin, !# P!l"e%"lene(

4trusion and palleti/ing is the first operation as the polyethylene leaves the

reactor. &he semi liuid polyethylene is pumped 'y a screw inside a 'arrel and it is

forced through a die with holes of appro4imately 1G> inch in diameter. &he polyethylene

is directly e4truded through into water 'ath which free/es it. rotating !nife or a similar

device chops or dices the e4truded polymer as it leaves the die to form pellets. @efore

passing through e4truder certain additives are used in order to incorporate certain

processing properties.

Drying: 8rying the polyethylene pellets is the ne4t operation. Aree water is first drained

from the pellets. Aor drying purpose we use a rotary dryer.

&he last step is of storing the pellets in the silos or hoppers

16


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Chapter No 2 Material Balance 1>

Maerial Balance

Acr!ss T*+*lar reac!r(

Aeed L recycle - :?36.0> %gGhr

*onversion - 3

".. Arom Beactor - 2::::.:> !gGhr

thylene from Beactor-1>:.3 !gGhr

Cut put from Beactor - :?36.0> !gGhr

Acr!ss Hi,% Press*re Separa!r(

fficiency of +"# - ?

thylene Becovery from +"#-,?00:.?, !gGhr

thylene in the product #tream -2:?.36 !gGhr

". from +"# - 2::::.:> !gGhr

&otal mount in Becycle stream - ,?00:.?, !gGhr

&otal mount in "roduct #tream - 303:.1, %gGhr

Acr!ss L!$ Press*re Separa!r(

fficiency - 100

thylene recovery from 9"# -2:?.36 !gGhr

1>


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*hapter


23/148

*hapter


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*hapter


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*hapter


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28/148

*hapter


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*hapter

2>


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*hapter


31/148

*hapter ;OE0:

Parameter Primary Compressor Secondary Compressorotal Ethylene

Enterin!"#!$hr%

303:.1 :?36.1

Ethylene for Sin!le

Battery "#!$hr%

60:1.,3 1>:3

Molar flo& 'ate

"!(mol$hr%

216,1?.33, 6>02

)ol*metric flo&

'ate"m+$hr%

2,1.,: 63.362,

,nlet Press*re "atm% 1 216.2:

-*tlet Press*re "atm% 216.2: 31>0.

,nlet emperat*re "oC% 2 2

-*tlet emperat*re "oC% :> :>

Ethylene Density"#!$m+% 1.2603

Molec*lar &ei!ht"!$!(mol% 2>.0,

Critical press*re"atm% ,?.:,

Critical temperat*re"oC% ?.3

./era!e Compressi0ility 1actor 0.?>

Cp /al*e"cal$!(oC% 0.3?

as constant ' /al*e"3$!(mol(#% >.31,

)al*e of 4 "Cp$C/% 1.222

456$4 0.1>2

.dia0atic efficiency :6

Electric Motor Efficiency ?,

30


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*hapter .1*(2.,)0.1>2

&2 - 30.>6 %

&2 - ::.: o*

s &2 is less than 100 o* so our selected *ompression Batio (*.B.) - 2., is set.

k

k

P

P>>

1

1

212

=

31


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*hapter


34/148

*hapter


35/148


36/148

*hapter G0.:6

7c - ,,>1.2? calGg.mol

#imilarly 'y putting the values in the a'ove formula find the shaft wor! for the

Secondary Compressor

7c - 1:02.>>?G0.:6

7c- 22,0.6, calGg.mol

STEP NO %

&o calculate the compressor horsepower use the following formula

7here

c

Ac

=

CC nP =

3


37/148

*hapter 02 * 22,0.6, P 0.000001163

"c - 1,:,.,1 %7

"c - 1,:,.,1 P 1.3,1

"c - 1?::.1:? hpSEP N-( 7

&o si/e the electric motor divide the compressor power 'y an electric motor

efficiency

7here

"- lectric motor power (hp)

"c - *ompressor power (hp)

5

C5

PP

=

36


38/148


39/148


40/148

*hapter


41/148

*hapter 1.,

,0


42/148

*hapter


43/148

*hapter


44/148

*hapter


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*hapter o

* &2-2o

*

t2- , o* t1-20

o*

"roperty thylene thylene 7ater 7ater Inlet &emperature :>o* 31.1% 20 o* 2?3.1% Cutlet &emperature 2o* 2?>.1% ,o* 31>.1%

vg. #pecific +eat 0.,1calGg.o*

1:16.6:QG%g.o*

0.??> calGg.o*

,1:>.626QG%g.o*

vg. &hermal

*onductivity

0.023

7Gm.o*

0.62

7Gm.o*vg. 8ensity 2.> %gGm3 ??,.?

%gGm3

vg. iscosity 0.000011

%gGm.sec

0.000>10

%gGm.sec

Heat Load

>mCpF =

7here

W - +eat produced (QGhr)

m - Mass flow rate of thylene (%gGhr)

*p - #pecific heat of thylene (QG%g.

o

*)

,,


46/148

*hapter 2)

W -23??102 QGhr

W -23??102P0.0002:::::>

W - 13,,,.21 watt

Lo! Mean emperat*re Difference "LMD%:

9M&8-t2t1G9n(t2Gt1)

9M&8- 1,.>,o*

.SSUMED C.LCUL.,-NS:

ssume the value of over all heat transfer coefficient $8

$8-32 7G m2 o*

Heat ransfer .rea :

-W G ($8P9M&8)

- 13,,,.21 G (32P1,.>,)

- 31.>2 m2

*0e Layo*t ; Si9e:

9ength - m

C8 @7= pitch - 1?.0mm 1, @7=

23.>1 mm &riangular pitch.

"ass - 1

rea of #ingle &u'e - & - Ao

7here

,


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*hapter


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*hapter 0

Prandtel No( = Pr = Cp $ 4

7here

*p - #pecific heat of ethylene - 1:16.6:0 DG!g o*

X - iscosity of water - 0.000011 !gGm sec

! - &hermal conductivity of thylene - 0.023 7Gm o*

"randtel


49/148

*hapter

- 1?.0P(106.32G0.31?0)P(1G2.1,20)

b %49&4, mm

b &%? m

S%ell clearance 1 2234 ))

Insi.e .ia)eer !# s%ell 1 Ds 1 B*n.le .ia 5 s%ell clearance

Inside diameter of shell = Ds = 286.87 + 11.0 = 297.87 mm

@affle spacing - 9@ - 8sG, - 2?:.>:G, - :,.,: mm

"t- triangular pitch - 1.2P do

"t - 1.2P1?.0 - 23.>1mm

Shell area = .s = "Pt 5 do%@Ds@LB $ Pt

s - R(23.>1 T 1?.0) P 2?:.>: P :,.,: U G 23.>1

s - ,,36.,1 mm2

s - .00,, m2

EA*i/alent dia = De = 6(6$do@"Pt25"?(6@do

2%

8e - 1.1G1?.0 P R(23.>1)2T Y 0.?1: P (1?.0)2ZU

uivalent dia - 8e - 13.3 mm - 0.01, m

Mass flow rate of water - 2>:.>, !gGhr

Mass flo& rate of &ater

)ol*metric flo& rate of &ater =

Density of &ater

olumetric flow rate of water - 2>:.>, G ??,.? m3G hr

olumetric flow rate of water - .31 m3G hr

olumetric flow rate of water - .31 G 3600 m3G sec

olumetric flow rate of water - 0.001,:63 m3G sec

,>


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*hapter De*s$

7here

$s- #hell side velocity - 0.333 mGsec

= iscosity of water - 0.000>10 !gGm sec

8e- uivalent dia - 0.01, m

BeynoldKs .?:3

Prandtel No( = Pr = Cp$#

7here

*p - #pecific heat of water - ,1:>.626 DG!g o*

X - iscosity of water - 0.0000>10 !gGm sec

! - &hermal conductivity of water - 0.62 7Gm o*

"randtel


51/148

*hapter 3?.2, "a

["s - .20 "si

SPECIFICATION SHEET FOR INTER COOLER

,dentification:4changer

No( 'eA*ired- ,0

0


52/148

*hapter .1%

&u'es C81?mm 1,@7=

106 tu'es each m long

1 pass

2,mm triangular pitch

pressure drop - 16 %pa

Shell Side:

Aluid handled 7ater

Alow rate 2>:.>, %gGhr

#hell 13.3mm dia 1 pass

@affles spacing :,.,:mm.

"ressure drop - 3.>, %pa

"ressure 101.32%pa

&emperature 2?3.1% to

31>.1%

$dassumed - 32 7G m2 o* $d calculated -30?.12 7Gm2o*

1


53/148

Chapter No * Reactor de>in 3

"EACT#" DES$%N

$HT I! RECTORF

*hemical reactors are vessels that are designed for a chemical reaction to occurinside of them. &he design of a chemical reactor deals with multiple aspects of chemicalengineering.It is the Do' of the chemical engineer to ensure that the reaction proceeds withthe highest efficiency towards the desired output product producing the highest yield of

product while reuiring the least amount of money to purchase and operate.


54/148

Chapter No * Reactor de>in ,

It is important to note that while e4plicit guidelines for reactor selection are not availa'lethere are some general rules of thum' that can 'e followed in the selection process of anappropriate reactor for a given reaction.F &hese are 'riefly summari/ed here

6( Aor conversions up to ? percent of euili'rium the performance of five or more *#&Bsconnected in series approaches that of a "AB.

2( *#&Bs are usually used for slow liuidphase or slurry reactions.+( @atch reactors are 'est suited for smallscale production very slow reactions thosewhich foul or those reuiring intensive monitoring or control.

K( &he typical si/e of catalytic particles is appro4imately 0.003 m for fi4ed'ed reactors0.001 m for slurry reactors and 0.0001 m for fluidi/ed'ed reactors.

I( 9arger pores in catalytic particles favor faster lowerorder reactions5 conversely smallerpores favor slower higherorder reactions.

DE6ELOPMENT OF CHEMICAL REACTION RATE

E/PRESSIONS(

It is normally necessary to use a simplified or empirical e4pression for the reaction rater in terms of constants and concentrations of reactant and product that can 'e assumed fromthe stoichiometry of a proposed reaction mechanism or developed purely empirically on the'asis of e4perimental data. Cne of the !ey components of the rate e4pression is the specificrate constant ! which must almost always 'e determined directly from la'oratory dataalthough some theoretical e4pressions do e4ist.

&he most common form of presenting a rate constant is in the form of the rrheniuseuation as

4 = .e5E$'

where ! is the specific rate constant with appropriate units to fit the rate euation the freuency factor with units identical to those of ! a the activation energy with units thatma!e aGB& dimensionless B the ideal gas law constant and the a'solute temperature.

It is worthwhile to note that sincg tfee reaction constant is dependent on the temperature the reaction rate is also dependent on the temperature. &he effect of temperature on thereaction coefficient and reaction rate can 'e su'stantial for even small temperature variations.&he sensitivity of reaction rates to temperature variation is due to the dependence of therrhenius rate coefficient on the e4ponent of the negative inverse of the reaction temperature.

&his dependence is illustrated in 4ample 133 with the gasphase degradation of dinitrogenpento4ide at temperatures of 2?3 and 303 %.

REACTOR PRINCIPLES

&he 'asic mathematical model for a reactor system is developed from (I) reaction ratee4pressions incorporating mechanism definition and temperature functionality5 (2) material

,


55/148

Chapter No * Reactor de>in

'alances including inflow outflow reaction rates mi4ing effects and diffusion effects5 (3)energy 'alances including heats of reaction heat transfer and latent and sensi'le heat effects5(,) economic evaluations5 and () special constraints on the design system.

Reac!r T"pes

&he common ideali/ed designations for types of reactors are 'atch plugflow and

'ac!mi4 or continuous stirred tan!. In an ideali/ed 'atch realtor the reactants initially arefully mi4ed and no reaction mi4ture is removed during the reaction period.

*omplete mi4ing is assumed during the reaction so all their reactor contents are atthe same temperature and concentration during the reaction process. &he composition (andoften the temperature) changes with time. &he ideali/ed plug reactor is a tu'ular reactor inwhich the reacting fluid moves through the tu'e with no 'ac! mi4ing or radial concentrationgradients. *onditions are at steady state so that the concentration as well as the temperatureprofile along the length of the reactor does not change with time. n ideali/ed 'ac!mi4 flow

reactor is euivalent to a continuous stirredtan! reactor (*#&B) where the contents of thereactor are completely mi4ed so that the complete contents of the reactor are at the sameconcentration and temperature as the product stream. #ince the reactor is designed for steadystate the flow rates of the inlet and outlet streams as well as the reactor conditions remainunchanged with time. &hese three 'asic types of reactors represented schematically in Aig.13Q3 form the 'asis for all reactor designs with modifications to meet specific needs.

In reality very few reactors can fulfill the reuirements for ideality and the designengineer therefore must generally design for non ideal reactors.

Space 6el!ci" an. Space Ti)e

Alow reactor analysis often utili/es two concepts space velocity and space time. #pacevelocity is defined as the ratio of the volumetric feed rate to the volume f the reactor whichpermits determination of the num'er of reactor volumes of feed that can 'e treated inuring aspecified time period.

CHAIN-GRO7TH POLYMERIZATION

*haingrowth polymeri/ations reuire the presence of an initiating molecule thatcan 'e used to attach a monomer molecule at the start of the polymeri/ation. &he initiatingspecies may 'e a radical anion or cation as discussed in the following sections. Areeradical anionic and cationic chaingrowth polymeri/ations share three common steps initiation propagation and termination. 7hether the polymeri/ation of a particularmonomer can occur 'y one or more mechanisms (i.e. free radical anionic or cationic)depends in part on the chemical nature of the constituent group. Monomers with anelectronwithdrawing group can polymeri/e 'y an anionic pathway while those with an


56/148


electrondonating group follow a cationic pathway. #ome polymers with a resonancesta'ili/ed constituentgroup such as a phenyl ring may 'e polymeri/ed 'y more than onepathway. Aor e4ample polystyrene can 'e polymeri/ed 'y 'oth freeradical and anionicmethods.

AreeBadical "olymeri/ation and *opolymeri/ation

9i!e other chaingrowth polymeri/ations a freeradical polymeri/ation has threeprincipal steps\ Initiation of the active monomer\ "ropagation or growth of the active (freeradical) chain 'y seuential addition ofmonomers\ &ermination of the active chain to give the final polymer productInitiation. Initiation in a freeradical polymeri/ation consists of two steps\ a dissociation of the initiator to form two radical species followed 'y addition of a singlemonomer molecule to the initiating radical (the association step). &he dissociation of the

initiator (II) to form two freeradical initiator species (E\) can 'e represented as

"ropagation. in the ne4t step called propagation additional monomer units are addedto the initiated monomer species as

&ermination"ropagation will continue until some termination process occurs. Cne o'vious

termination mechanism occurs when two propagating radical chains of ar'itrary degrees ofpolymeri/ation of 4 and y meet at their freeradical ends. &ermination in this manner occurs

'y com'ination to give a single terminated chain of degree of polymeri/ation Dc L y throughthe formation of a covalent 'ond 'etween the two com'ining radical chains as illustrated 'ythe following reaction

6

.2 7; d

K

..

7##7 ak+

( )

( ) ( ) .1

.

.

2

.

..

##7###7

##7#7##

7###7#

.

k

.

k

k

p

p

p

++

+

+

( ) ( ) ( ) ( )

( ) ( ) ( ) 7#77####7

7##77####7

y.

k

y.

y.

k

y.

t

t

+

+

++

1

..

1

1

..

1


57/148

Chapter No * Reactor de>in :

8ineics(

&he rate euations of Initiation propagation and termination from their corresponding

euation are respectively given 'elow.

t steady state

ri-rt#o we get

lso 'y solving riand rpwe get the following euations.


58/148

Chapter No * Reactor de>in >

Bate euation of Monomer conversion at any time

Deer)inin, %e 6!l*)e O# %e reac!r(

8ata from the literature

Rate Con>tant 7a=ue o@ rate con>tant Re@@erence%th lGs 6.0, 103 e4p R3.6:0:

10,(& L 2:3.1)1U@randolin et al.

(1??6)5 8hi' andl

103(& L 2:3.1)^1]

%tc lGs ,.3 10> e4p ]^1.>36? 103(& L 2:3.1)^1]

%trm lGs 1.2 10 e4p ]^:.2,61 103(& L 2:3.1)^1]

%trp lGs 1.> 10> e4p ]^,.:303 103(& L 2:3.1)^1]

%] lGs 1., 10? e4p ]^?.611, 103(& L 2:3.1)^1]

%]1 lGs ,., 10? e4p ]^?.611, 103(& L 2:3.1)^1]

%td lGs 3.2,6 10> e4p ]^1.21:> 102(& L 2:3.1)^1]

%trs lGs .6 10: e4p ]^.0,>, 103(& L 2:3.1)^1

%d lGs 2.2?2 101, e4p]^1.163 10,(& L

2:3.1)^1]

#eidl and 9uft(1?>1)5 8hi' and

l

( )

= t

k

tk;fkk##

t

ddp

21

e4pe4p o

o


59/148

Chapter No * Reactor de>in ?

6al*es O# Rae C!nsans(

t our reactor conditions op temperature. &he calculated values of rate constants are as

follows.

#p=+(?6?K L$mol(sec

#t=6(6?5K L$mol(sec

#d=''#(6$sec

Selecin, %e M!n!)er C!n9ersi!n(

@y the reference of chemical Dournal NInternational Qournal of *hemical reactorngineeringO 7e have the following graph of the monomer conversion to te reactor length.

&hus 'y the a'ove data we selected a monomer conversion with one inDection to 'e 12 .

?


60/148


Calc*lain, %e 6!l*)e O# %e Reac!r(

8ata availa'le

Kp 3.0>410, L/mol.sec

Kt 1.?410, L/mol.sec

Kd 0.038 1/sec

Efficienc 80! "ss#med

E:*ai!n !# )!n!)er c!n9ersi!n(

) Con*ersiom !+,r -0.129602 28.683650.25898 28.733570.388132 28.783550.517061 28.833610.645766 28.88375

0.774247 28.933950.902505 28.984231.030541 29.034571.158355 29.0851.285948 29.135491.41332 29.186051.54047 29.236691.667401 29.28741.794112 29.338191.920604 29.389042.046877 29.43997

2.172932 29.490972.298768 29.542052.424387 29.593192.54979 29.644412.674975 29.69571

60

( )

= t

k

tk;fkk##

t

ddp

21

e4pe4p o

o


61/148


6!l*)e


62/148


M!.elin, an. Si)*lai!n #!r %e M*li In;eci!n !# %eIniia!r

Arom the data o'tained from the International Qournal Cf *hemical Beactor ngineeringwe have the following set of euations

To account for the density variation of reacting mixture feed, thedensity correlations of

In the following equation for the density variation:

62


63/148


Ass*)pi!ns(

The reactor model is based on the following assumptions:

1. The heat capacity of reaction mixture is the sum of the heat capacitiesof pure components only.2. verall heat transfer coe!cient, following the approach of "hen et al.#1$%&', is given by

where,hiis the calculated heat transfer coe!cient on reaction side, andhwrepresents the (lm coe!cient for metal wall, reactor )ac*et, and fouling

e+ect.. The pressure inside reactor is *ept constant, and there is no pulse valvee+ect.-. Initiator, being present in small amounts, does not a+ect the owdynamics, and heat transfer of reaction mixture./. 0ropagation is the only thermally relevant step #randolin et al., 1$'to be considered in the energy balance of reactor.

63


64/148

Chapter No ' Opti


65/148

Chapter No ' Optipreti, 2??-' was

applied. The reactor was considered to be surrounded by contiguous)ac*ets of equal length, and at uniform #but not necessarily equal'temperatures.

Thus, the temperature of )ac*ets, i. e. the control function, wasrepresented by a series of step values, or control stages. The step si5e,or the length of contiguous )ac*ets, was *ept constant over the lengthof reactor. The number of control stages, the di+erential4algebraic

model #sans the energy balance for )ac*et' with its parameters, andthe reactor temperature constraint of 8quation #1' were input to theoptimal control method. These inputs are needed to evaluate theperformance index or @(tnessA for a given control function. Theapplication of the method yielded the optimal control function bystochastically applying genetic operations on a randomly generatedset or @populationA of control functions constrained by 8quation #1-'.

The optimal control method of >preti #2??-' uses three geneticoperations, namely, selection, crossover and mutation iteratively in asi5e4varying control domain with logarithmic and linear mappings. The

method does not require any input of feasible control solution, or anyauxiliary condition. 3election stochastically pic*s control functions fromtheir population on the basis of (tness. B control function with better(tness has a greater probability to populate a new set of controlfunctions. "rossover wor*s on the new set or population, which has agreater representation of control functions with better (tnesses.

66


66/148

Chapter No ' Opti


67/148

Chapter No , Preheatin in the tu;u=ar reactor 6?

PREHEATING IN THE

TUBULAR REACTOR

Desi,n(

Mass flow rate for one loop - mH-2::::.>G6

- ,62?.0 %gGhr

&he temperature of the gas is to increase

Arom :?_*10_*.

#o the average temperature - :?L10G2 -11,_*

`t - 220_A

*p of ethylene at 11,_* - 1.>?> %QG%g_*

#o the heat load will 'e given as

W - mHP*p P `t

- ,?26P1.>?> P :1

- 2.11P10 7att

- :.?P10 %QGhr

Mass flow rate of steam to preheat the gas.

mHs- W G

7here - latent heat of vapori/ation.

t 220_* - 1> %QG%g_ *

6?


68/148

Chapter No , Preheatin in the tu;u=ar reactor :0

mHs -:.?P10 G 1>

- ?0, %gGhr

mHs - 1?>>.> l'Ghr

9M&8 - (220 :?) T (220 10)G ln(1,1G:0)

- :1 G 0.:0

- 102. _ *

- 12,_ A

7e assume $d - 2> 7attGm2 _ *

W - $d P P 9M&8

- W G $dP 9M&8

- 2.11P10 G 2>P102.

- :3. mb

FOR PIPE SIDE(

8ia of the pipe

I8 (inner dia) - :0 mm

(I8) - 0.0: m

C8 (outer dia) - 1:0mm

- 0.16?> mAlow area - p - G,P(I8)b

- G, P(0.0:)b

- 0.003> m2

Mass velocity =p - mH G p

- ,62?.0 G 0.003>

- 1.2:P106%gGhr m2

t an average temperature of 11,_* viscosity of ethylene

- 0.10>2 %gGhr m

Beynolds no. of pipe Bep- 8 P =pG

- 0.06?> P ,62?.0G 0.10>2

Bep - :?2000

Arom graph at this Beynolds no the value of

:0


69/148


Q+ - 1100 (appro4imately)

lso at 11, _* heat capacity of ethylene

*p - 1.>?> %QG%g_*

&hermal conductivity %- 0.0>:2 wattGmb(_*Gm)

(*pP G %)1G3- (1.>?>P0.10>2G0.0>:2)1G3

- (2.3,)1G3

- 0.:>2

hi - Q+ P (*pP G %)1G3 P (%G8) P(Gw) .1,

hi - 1100 P 0.:>2 P0.03P

hiG - ,3,.2 7attG m2_*

FOR ANNULUS(

Inner dia of the annulus - 82 - 2, mm

- 0.2, m

Cuter dia of the pipe - 81- 0.16?> m

Alow area a- G, R(8b2 T 8b1)U

- G, R(0.2,)b (0.16?>)bU

- G, (0.032)

- 0.02> mb

uivalent dia -8e- (8b2 T 8b1)G81

-0.032G0.16?>

- 0.210 m

Mass velocity =a - mHsG a

- ,0?G0.02>

- 1.,?P 10,%gGhr m2

iscosity of steam at 220_*

- 2.,2 %QG%g _*

BeynoldKs no. - 8eP =aG

- 0.210P1.,?P 10,G2.,2

- ::00

:1


70/148


t this no. the value of Q+ from graph- 160

nd *p of steam -2.,2 %QG%g _*

&hermal conductivity - 0.0,1 7attGmb(_*Gm)

- 0.1,? %QGhrGmb(_*Gm)

(*pG%)1G3 - (2.,2P0.06,>G0.1,?)1G3

- 0.3

ho Gmb(_*Gm)- Q+ P (*pG%)1G3P(%G8e)P(Gw)) .1,

- 160 P 0.3 P 0.3:,P

hoG - 32.3 :2

hio - hi P I8GC8

- hiG P 0.0:G0.16?>

hioG - ,3,.2 P 0.0:G0.16?>

- 1>2.36 7attGmb _*

2.36G( 1>2.36L32.3)P (22011,)

- 11, L (0.>,>)P106

- 11, L >?.>

- 20 _*

t wall temperature the viscosity of ethylene

w - 0.126 %gGhr m

Aor ethylene G w - (0.10>2G0.126) 0.1,

- 0.?>,

nd the viscosity of water

w - 0.06,> %gGhr m

Aor water - (G w)0.1,- 1.0

hoG - 6.>0

ho - 32.3P1.0

- 32.3 7attGmb _*

hio - 1>2.36P 0.?>,

- 1:?.,, 7attGmb _*

:2


71/148


$c -hioPhoGhioLho

$c - (1:?.,,P32.3)G(1:?.,,L32.3)

->3:.1G21,.::

- 2>.2: 7attGmb _*

1G$d- 1G$c L Bd

1G$d-1G2>.2:L.01

- 0.033L0.001

- 0.0363

Cur assumption is correctso

$d-1G0.0363

-2:. 7attGmb _*

W - $dPP9M&8

-WG$dP9M&8

-2.11P10G2:.P102.

- :3.2 mb

lso

- P 8 P9

Cr

9 - G P 8

- :3.2G3.1,0.0:

9 - 333 m

9ength of one tu'e -10 m

&otal no of tu'es - 333G10

- 33.3 -3,

Reaci!n an. c!!lin,

Mass flow rate for one loop - mH-2::::.>G ,

-6??,,.2 %gGhr

-12:: l'Ghr.

&he temperature of the gas is to increase

:3


72/148

Chapter No , Preheatin in the tu;u=ar reactor :,

Arom 110_*1:0_*.

#o the average temperature - 110L1:0G2

-1,0_*

`t - 220_A

*p of ethylene at 220_A - 0.,6 @tuG_A.l'

#o the heat load will 'e given as

W - mHP*p P `t

- 12::P0.,6 P220

- 10 P 10 @tuGhr

mass flow rate of steam to preheat the gas.

mHs- W G

7here - latent heat of vapori/ation.

at 230_* - 1>13 %D G %g

s W - 10 P 10 @tu G hr

#ince 1 @tu - 10 Doule

&herefore W - 10 P 10 P10 DGhr

-16,0 P 10 %D G hr

mHs - 16,0 P 10G 1>13

- ?0, %gGhr

mHs - 1?>>.> l'Ghr

9M&8 - (230 110) T (230 1:0)G ln(120G60)

- 60 G 0.6?3

- >6.6_ *

- 12,_ A

7e assume $d - .0 @tuGhr ftb. _A

W - $d P P 9M&8

- W G $dP 9M&8

- 10 P 10 G P 12,

:,


73/148

Chapter No , Preheatin in the tu;u=ar reactor :

- 216 ftb

- 233 mb

FOR PIPE SIDE

8ia of the pipe

I8 (inner dia) - 12.0? in

(I8) - 1.0 ft

C8 (outer dia) - 12.: in

- 1.06 ft

Alow area - p - G,P(I8)b

- G, P(1)b

p - 0.:> ftb

Mass velocity =p - mH G p

- 12:: G 0.:>

- 1?,61 l'G hr ftb

t an average temperature of 220_Aviscisity of ethylene - 0.031, l'Ghr.ft

Beynolds no. of pipe Bep- 8 P =pG

- 1 P 1?,61 G 0.031, Bep - 6:00.0 P10

Arom graph at this Beynold nothe value of

Q+ - 1300 (appro4imately)

also at 220 _A heat capacity of ethylene

*p - 0.,6 @tu G l' _A

&hermal conductivity %- 0.0161

(*pP G %)P1G3-(0.,6P0.031,G 0.0161)P1G3

- 0.32

hi - Q+ P (*pP G %)1G3 P (%G8) P(Gw)).1,

hi - 1300 P 0.33 P 0.0161P

hiG - 6.?0

:


74/148


FOR ANNULUS(

Inner dia of the annulus - 82-20 in- 1.6: ft

Cuter dia of the pipe - 81- 1.06 ft

Alow area a- G, R (8b2 T 8b1U

- G, R 1.6:b 1.06bU

- G, (1.63)

- 1.2:> ftb

uivalent dia -8e- 8b2 T 8b1G81

-1.63G1.33

-1.23 ft

Mass velocity =a - mHsG a

-1?>>.>G1.2:>

- 1:.3 l'Ghr

iscosity of steam at 230_*(3>2_ A)

- 0.01 P 2.,2

- 0.03,2 l'Gft.hr

BeynoldKs no. - 8eP =aG

- 1.21 P 1:.3G0.03,2

- 6:00

t this no. the value of Q+ from graph- 10

nd *p of steam -1.13 @tuGl'_A

&hermal conductivit - 0.01>0

(*pG%)1G3 - (1.13P0.03,2G0.01>0)1G3

-0.>> ho - Q+ P (*pG%)1G3P(%G8e)P(Gw)).1,

- 10 P 0.>> P 0.06G1.23 P

hoG - 6.>0

hio - hi P I8GC8

:6


75/148


76/148

Chapter No , Preheatin in the tu;u=ar reactor :>

- 332> ftb

- 310 mb

9 - G P 8

- 310G3.1,P0.0:

9 - 1,10 m

9ength of one tu'e -10 m

&otal no of tu'es - 1,10G10

- 1,1

Press*re .r!p #!r pipe si.e(

f - .003L(0.26,)GBe0.,2

-0.003L(0.26,)G(:.:210)0.,2

-0.003L0.0000>>

-0.00,3>

`Ap-,f=p29pG2g

:>


77/148

Chapter No Dr*ms >0

DRUMS

General(

&he containers in which the feedstoc!s intermediate products and final products areheld are generically !nown as vessels. Belatively large capacity vessels are calledstorage tan!s and small capacity vessels are P called drums. In a refinery drums arewidely used not only as procesr units 'ut also as utility and offsite facilities.

&he types of drums and their internal construction vary depending upon the !ind ofservices in which the drums are used5 mainly they are used for the following purposes\ apor9iuid #eparation (incl. apor 8isengaging) 9iuid #urge 9iuid9iuid #ettling&he typical names of drums used in a refinery are summari/ed in &a'le ,1 together withtheir functions.

6ap!r-Li:*i. Separai!n

&he vaporliuid separation is accomplished 'y feeding the mi4ed phase fluid intoa separation drum where the vapor and liuid are separated 'y allowing the vapor to riseand 'e discharged at the top of the drum and the liuid to settle and 'e drawnoff the

'ottom of the drum.

In these services the vapor velocity must 'e sufficiently low to prevent e4cessiveliuid entrainment. &he demister pad (crin!led wire mesh screen) is sometimes providedat the vapor outlet for this purpose as shown in Aig. ,1. &ypical applications are theservices where even moderate entrainment can have a detrimental effect upon theprocess and are utili/ed where economical to ma!e possi'le the use of higher vaporvelocities in the drum design such as the compressor suction drum. &he demister pad is

>0


78/148

Chapter No Dr*ms >1

usually 100 to 10 mm thic! depending on type5 demisters 20 to 300 mm thic! are usedfor special applications such as for a fine mist vapor. +owever the efficiency of thedemister is not proportional to its thic!ness. n increased thic!ness will in most caseslead only to a greater pressure drop and higher initial costs with little or no compensatory'enefits.

If the velocity of the vapor through the demister pad is too low liuid particles will passthrough the demister pad and 'e carried away with the vapor. If the velocity of the vaporis too high liuid will 'e forced to the top of the demister5 'loc!ing the passage of thevapor.

Li:*i. S*r,e

&he liuid surge drums are provided to hold the process liuid fluids for a certainnecessary holdup time and act as a 'uffer 'y a'sor'ing fluctuation in the.

Operain, c!n.ii!ns(

&he liuid holdup time is determined 'y the process control system or 'Semergency reuirements. $nder normal circumstances the holdup in a liuid surge drum'etween the high and low liuid levels can 'e maintained for to 1 minutes 'ased onthe pumpout rate. @asic configurations of liuid surge drums is same as the drum.

Li:*i.-Li:*i. Selin,

&he drum is used for an 9"= caustic treatment facility. &his treatment is used toremove impurities such as mercaptan from 9"=. @asically the liuidliuid settling isachieved 'y using the difference in densities 'etween two phases. settling 'affle orcoalescer pad li!e a demister and is sometimes used where economical to reduce thesettling time.

ertical settling pots ('oots) are often used on hori/ontal drums where a smallvolume of water or other heavy phase material is withdrawn.

Mec%anical C!n#i,*rai!n !# Dr*)(

No99les:

>1


79/148

Chapter No Dr*ms >2


80/148

Chapter No Dr*ms >3

Na3


81/148

Chapter No Dr*ms >,

>,


82/148

Chapter No - Hih pre>>ure !eparator >6

HIGH PRESSURE

SEPARATOR

$nconverted ethylene from the reactor -1>:.3 %gGhr

#eparation of unconverted ethylene from the first separator

- ? of total unconverted ethylene.

-1>:.3P0.?

-,?00:.?3

8ensity of ethylene gas in the first separator at temperature 230_* and pressure 166.:atm. Cr 16>>:.> %pa from graph - 6 molGdm

-16> gG dm

-16> %gGm

v -2?1.:0 mGhr.

8ensity of the mi4ture (polyethyleneL ethylene)in the first separator can 'e calculated

s

&otal weight of polyethylene mi4ture - 2::::.> L 2:?.36

-303:.1, %gGhr

>6


83/148


84/148

Chapter No - Hih pre>>ure !eparator >>

- 0.10 P (32G16>)j

- 0.10 P (1.>)

v - 0.1:> mGsec.

rea of separator is given as

v- v

v - 2?1.:0 mGhr

- 0.10> mGsec.

- vG v

- 0.10> G 0.1::

- 0.62, mb

9iuid level in the separator is given 'y the formula

9l P - 9 P ts.

7here

9l - liuid level in the separator (m)

ts - residence time in the separator(sec)

- 2 min

-0.033 hr

99 - 9P tsG

- ,3.36 P 0.033 G 0.62,

99 -2.0 m

8iameter of the separator is given as

- G, P 8b

8 - (, P G ) j

- (, P 0.62,G ) j

-0.>>3 m


85/148

Chapter No - Hih pre>>ure !eparator >?

- 2.0 L1.32 L 0.,:2

9 - 3.:

9G8 - ,.2,

C!!ler a#er %i,%-press*re separa!r

&1-230o* &2-2

o*

t2- ,o* t1-20

o*

Chapter !Hea L!a.(

>mCpF =

7here


m - Mass flow rate of thylene (%gGhr) -,?0: !gGhr*p - #pecific heat of thylene (QG%g.o*) - 201.63 QG%g 0*

W - ,?0:P201.63P(2302)

W -216,::1:,QGhr

W -216,::1:, QGhr G3600 sec

W - 6??021.,3: watt

>?


86/148

Chapter No Lo pre>>ure >eparator ?1

LO0 PRESSURE

SEP-R-TOR

$nconverted ethylene from the +igh pressure separator - 2:?.36 %gGhr

#eparation of unconverted ethylene from the low pressure separator

- 100

-2:?.36%gGhr

8ensity of ethylene gas in the first separator at temperature 220_* and pressure 1 atm.

from graph - 0.03 molGdm

-0.>, gG dm

-0.>, %gGm


87/148


v -%v (( liuid T vapors)G vapors) j

7here

%v- velocity constant (mGsec) calculated 'y relation 79G7v P ( vaporG liuid)

79-Mass flow rate of liuid %gGhr

7-Mass flow rate of vapors %gGhr

79G7v P liuid G vapor

-303:.1,G2:?.36 P (0.>,G:0)j

- 11.:6P 0.033,

-0.,

t this the value of %v from graph is 0.2 ftGsec or 0.0:62 mGsec. this velocity

constant is in the presence of mist eliminator.

v - 0.0:602 P ((:00.>,)G0.>,))j

- 0.0:602 P (:,?.16G0.>,)j

- 0.0:602 P (2?.>63)

v - 2.1>mGsec.

rea of separator is given as v- v

v - 30:0.6:2 mGhr

- 0.0>2 mGsec.

- vG v

- 0.>2 G 2.1>

- 0.,: mb

9iuid level in the separator is given 'y the formula

9l P - 9 P ts.

7here

9l - liuid level in the separator (m)

&s - residence time in the separator (sec)

-2 min

-0.033 hr

99 - 9P tsG

- ,0.,: P 0.033 G 0.,:

?2


88/148


9l - 1.> m

8iameter of the separator is given as

- G, P 8b

8 - (, P G ) j

- (, P 0.,:G ) j

-0.:632 m


89/148

Chapter No Lo pre>>ure >eparator ?,

o* QG%g.o* calGg.o* QG%g.o*

vg. &hermal

*onductivity

0.02>

7Gm.o*

0.62

7Gm.o*

vg. 8ensity 0.>3 %gGm3 ??,.?

%gGm3

vg. iscosity 0.00001:

%gGm.sec

0.000>10

%gGm.sec

Heat Load

>mCpF =

7here


m - Mass flow rate of thylene (%gGhr)

*p - #pecific heat of thylene (QG%g.o*)

W - 2:?.36P201.63P(2302)

W -10>,>,0036 QGhr

W -10>,>,0036 QGhr G3600 sec

W - 3013,,., watt

Lo! Mean emperat*re Difference "LMD%: 9M&8-t2t1G9n(t2Gt1)

9M&8- ,?.>,o*

?,


90/148

Chapter No Lo pre>>ure >eparator ?

.SSUMED C.LCUL.,-NS:

ssume the value of over all heat transfer coefficient $8

$8-1?2 7G m2 o*

Heat ransfer .rea :

-W G ($8P9M&8)

- 3013,,., G (1?2P,?.>,)

- 31.,? m2

*0e Layo*t ; Si9e:

9ength - m

C8 @7= pitch - 1?.0mm 1, @7=

23.>1 mm &riangular pitch.

"ass - 1

rea of #ingle &u'e - & - Ao

7here

8o - outside diameter of tu'e (m)

9 - 9ength of tu'e (m)

& - 3.1,2P.02P

?


91/148


& - 0.30 m2


92/148

Chapter No Lo pre>>ure >eparator ?:

7here

8t- &u'e inside diameter - 0.01,> m

$t- &u'e side velocity - ,.6 mGsec

=iscosity of thylene - 0.00001: !gGm sec

BeynoldsKs 3

Prandtel No( = Pr = Cp $ 4

7here

*p - #pecific heat of ethylene - 201.63 DG!g o*

X - iscosity of water - 0.00001: !gGm sec

! - &hermal conductivity of thylene - 0.02> 7Gm o*

"randtel


93/148


94/148

Chapter No Lo pre>>ure >eparator ??

'hell clearance = 11.0 mm

Inside diameter of shell = Ds = ("ndle dia + shell clearance

Inside diameter of shell = Ds = 286.87 + 11.0 = 297.87 mm

@affle spacing - 9@ - 8sG3 - 2?:.>:G3 - ??.2? mm

"t- triangular pitch - 1.2P do

"t - 1.2P1?.0 - 23.>1mm

Shell area = .s = "Pt 5 do%@Ds@LB $ Pt

s - R(23.>1 T 1?.0) P 2?:.>: P ??.2? U G 23.>1

s - >??.:?, mm2

s - .006 m2

EA*i/alent dia = De = 6(6$do@"Pt25"?(6@do

2%

8e - 1.1G1?.0 P R(23.>1)2T Y 0.?1: P (1?.0)2ZU

uivalent dia - 8e - 13.3 mm - 0.01, m

??


95/148


96/148

Chapter No Lo pre>>ure >eparator 101

Prandtel No( = Pr = Cp$#

7here

*p - #pecific heat of water - ,1>:.626 DG!go

*

X - iscosity of water - 0.0000>10 !gGm sec

! - &hermal conductivity of water - 0.62 7Gm o*

"randtel


97/148


F Pt= *0e side press*re drop = Np@G@f"L$di%2(IJ@>@*t2$2

where

@*s2$2

where

8s - #hell inside dia

9 - 9ength of tu'e

9@ - @affle spacing

102


98/148


["s - 3:13.?:1 "a

["s - .3? "si

103


99/148

Chapter No Lo pre>>ure >eparator 10,

Speci#icai!n S%ee #!r C!!ler a#er L!$press*re Separa!r

,dentification:4changer

1*nction:Bemove the +eat form ethylene

-peration:*ontinuous

ype:11 +ori/ontal

Heat D*ty- 1.0>4106%QGhr

*0e Side:

Aluid handled thylene =asAlow rate - 2:?.36 %gGhr

"ressure - 101.32%"a

&emperature - 03.1% to

2?>.1%

&u'es C81?mm 1,@7=

106 tu'es each m long1 pass

2,mm triangular pitch

pressure drop - 10.> %pa

Shell Side:

Aluid handled 7ater

Alow rate 10363.>> %gGhr

#hell 13.3mm dia 1 pass

@affles spacing ??.>:mm.

"ressure drop - 3:.13 %pa

"ressure 101.32%pa

&emperature 2?3.1% to

31>.1%

$dassumed - 1?2 7G m2 o* $d calculated -1:2.1>6 7Gm2o*

10,


100/148


DRYING OPERATION(

8rying of solids means the removal of relatively small amounts of water or

other liuid from the solid material to reduce the content of residual liuid to an

accepta'ly low value. 8rying is usually the final step in a series of operation and the

product from a dryer is often ready for final pac!aging.

Classification of Dryer ypes

wide variety of dryers are used in the process industries. +owever followingcriteria is employed to classify dryers

6( Method of -peration

&he first su'division is 'y method of heat transfer.

(a) *onduction +eating

(') *onvection +eating.

.

*lassification of 8ryers 'ased on Method of Cperation

2( Physical 1orm of 1eed

It must first 'e emphasi/ed that purely mechanical means should 'e used to reducethe moisture content of the wet feed to as low a figure as possi'le 'ecause with few

10


101/148


e4ceptions processes such as evaporation filtration and centrifuging are cheaper andfaster than euivalent processes in drying plant.

Baw pastes and sludges are difficult to handle into dryers and the drying rate

uic!ly slows down through the formation of superficial s!ins having a low permea'ility

to vapour. &his form of feed therefore reuires pretreatment 'y JperformingK into pellets

a'out mm cu'e or 'y forming granules with mi4ed'ac! fines

Classi#icai!n !# .r"ers +ase. !n p%"sical #!r) !##ee.(

3. #cale of Cperation

It will 'e seen that the num'er of types for continuous large scale drying is muchmore limited than for medium scale outputs.

Classi#icai!n !# .r"ers +" scale !# pr!.*ci!n

106


102/148


103/148

Chapter No Lo pre>>ure >eparator 10>

+( *apital cost

K( Method of operation

I( Belia'ility of unit

7( vaila'ility of data

( Wuality of product

( Maintenance cost

WH - SELEC '-.' D'E'O(

6( ype of feed:Cur feed is free flowing pellets k rotary dryer

'est handles the free flowing material .

2( ype of prod*ction:Cur plant is 'ased on continues operation

k rotary dryer is considered to 'e the 'est dryer as a NcontinuesO

unit.

+( Capital cost:Botary dryer has a low capital cost per unit of out

put.

K( Method of operation:*onvection is the method of operation

k rotary dryer is 'est suita'le for this method.

I( Handlin! of &ide si9e particles In rotary dryer wide

particle si/e distri'ution can 'e handled

10>


104/148

Chapter No Lo pre>>ure >eparator 10?

7( ./aila0ility of data:ither data is availa'le for designing or

not Botary dryer can 'e scaled up with sufficient success from

data given in the literature.

( 8*ality of prod*ct: dryer needs to 'alance a uality against

cost of production. k rotary dryer fulfills this need.

( Maintenance cost: Maintenance costs are often a maDor

consideration. "ast history shows rotary dryers have relatively low

maintenance cost.

Cperation of rotary dryer

rotary dryer consist of a revolving cylindrical shell slightly inclinedto the outlet. 7et feed enters one end of cylinder dry material discharges from the other.s the shell rotates internal flights lift the solids and shower them down through theinterior of shell.Botray dryers are heated 'y direct contact of heated gas with solids 'yhot gas passing through an e4ternal Dac!et or 'y stream condensing in a set oflongitudinal tu'e mounted on the inner surface of shell. &he last of these types is called asteam tu'e rotary dryer. In a direct indirect rotary dryer hot gas first passes throughDac!et and then through shell where it comes in contact with solids

. ypical dia!ram of a direct heat 'otary dryer

Desi!n considerations

10?


105/148


#olid feed rate and inlet moisture contents

&emperature of air and 98"

8iameter and length of dryer

#lope of drum

Botational speed of drum 8rying gas direction

9ifting flights

-perational parameters

Besidence time

Cutlet moisture contents

#olid feed rate and inlet moisture contents

#olid feed rate -2>222.22!gGh

Moisture contents -,,,.,,!gGh

-6(7"on dry 0asis%

110


106/148


&emperature of air and 98"

&he 'est drying efficiency is at the highest air temperature at the inlet and the lowest

air temperature (or highest air moisture) at the outlet. &he ma4imum at the inlet is limited 'y

1. &he strengthtemperature properties of the metals

2. +eat sensitivity of the solids and how long they are e4posed to heat cocurrent flow

allows high inlet air temperatures even for heat sensitive materials.

It is 'ecause when air enters the dryer it rapidly removes the moisture. In

concurrent the outlet temperature difference of solid is 1020*.@ut in countercurrent the outlet temperature of solid reaches to inlet temperature of air. #o cocurrent process is 'est for 98".

*are must 'e ta!en that outlet temperature of 98" does not e4ceed 6* 'ecauseat this temperature its heat distortion property will 'e affected. &herefore this is outlettemperature of 98".

Inlet temperature Cutlet temperature98" 30* 6*

ir 1:* :*

Cutlet temperature is found 'y formula

Nt - >

>>E ln


107/148


Inlet humidity of air -0.01!g of waterG!g of dry airInlet wet 'ul' temperature at 1:* -,*


108/148


Mass flow rate of entering air

Mass flow rate is calculated 'y this euation

m! - mass flow rate of entering air -

h0- inlet temperature of air -1:*

ha - outlet temperature of air -:*

Cs0- humid heat of air -1.02!DG!g*

-2.66P106G1.02P(1::)

m! -2.60P10,!gGhr

Mass flow rate of dry air

Mass flow rate is calculated 'y this euation

H0-humidity at inlet temperature-0.01!g of waterG!g of dry air

mg(1L0.01)-2.66P106G1.02P(1::)

- 2.60P10,G(1.01) !gGhr

m!- 2.:P10, !gGhr

Mass velocity of air

&he minimum air velocity is set 'y particle si/e.3>00!gGh or :::.6.l'Ghr is

adeuate for 3000 microns particle.

113

)( hahbsb

t

g

>>C

Fm

=

)()1(

hahbsb

t

bg

>>CFHm=+


109/148


110/148


- (,P6.>,G3.1,)0.D- +(? m "(K ft%

)ol*me of dryer olume of dryer is calculated 'y this euation

$a=)ol*metric heat transfer coefficient=Bt*$5h5ft+51

-mass velocity of air - :::.6 l'G hr ft2

D-8iameter of dryer -?.>, ft

- 0.P(:::.6)0.6:G?.>,Ua- ,., @tuGhr ft3A

[& -logarithmic mean difference dry 'ul' and wet 'ul' temperatures

- (3,:113)(16:113) G Rln (3,:113)(16:113)U -122.: A

Wt - heat transferred to solid and water - 2.2P106@tuGhr

- 2.2P106 G,.,P122.:

) - ,66>.3? ft

3

( 133.1?3 m

3

)Len!th of dryer

9ength of dryer is calculated as- olume of dryer G area of dryer- ,66>.3? G :3.6

Len!th of dryer= 63.: ft (1?.,2 m)

11

>B

F*

a

t

=

P

GBa G.0 6:.0=

)G()lnR(

)()(

8aha8bhb

8aha8bhb

>>>>

>>>>>

=


111/148


9G8 ratio =1?.,2G3.0 =6.

Slope of dr*m #lope of drum is !ept from 0 to H. More the slope of the drying drum

more will 'e forward driving force 'ut product a'rasion will also increase. 7e have !ept3H slope.

'otational speed of dr*m

Botational speed of drum may 'e 'etween 20 to 2 mGmin. @ecause thecircumference of our dryer is ?.,2 m so 20 mGmin or 2 revGmin is ta!en.

Dryin! !as direction

8rying gas direction is ta!en as cocurrent with wet solid 'ecause in counter

current the solid polymer temperature may suddenly rise to its degradation temperature.

No of fli!hts and radial hei!ht

- 2?

? flights are reuired using lip angle of ?0o(lip angle depend on the type of feed ?0ois

suita'le for free flowing particles)

116


112/148

Chapter No Lo pre>>ure >eparator 11:

'adial hei!ht

Badial height is ta!en as 1G> of 8 (8 in m )

Badial height - 3G>-0.3: m

Badial height

'esidence ime:

Besidence time or e4posure time is limited 'yproducts heat tolerance and 'y

euipment design .Aor e4ample in Botary dryers the residence time may 'e several

minutes 'ut in flash and spray dryers residence time is limited to a few seconds. &ime of

passing in rotary dryer can 'e. *alculated 'y relationship given 'y Ariedman and Marshall

&r - (0.23P9) G (#


113/148

Chapter No Lo pre>>ure >eparator 11>

Dp- average particle si/e of 'eing

handled micron

2 - mass velocity of air l'G hr ft2

2f -mass velocity of solid l'Ghr.ft2( of dryer cross section )

slope varies 0 to > cmGm

let # - 2 cm Gm-0.02 ftGft (or 3o)

Dp - 3000 micron

B - P(3000)0.- 0.0?1

2f - mass flow rate of solid G area of dryer

. - 61111.11G:3.6

. - >30.31 l'G

hr ft

&r- R(0.23P63.:) G(0.02P20.? P?.>,)U TR(0.6P(0.0?1P63.:P:::.6) G >30.31U

r=+E min*tes

-*tlet moist*re content

outlet moisture content should 'e of 0.000 of dried 98".

-0.000P2:::::.:>

-13.>> !gGhr

Speci#icai!n s%ee !# Dr"er

11>


114/148

Chapter No Lo pre>>ure >eparator 11?

uipment 8ryer

Aunction to reduce the moisture contents

Cperation *ontinuous

&ype direct heat rotary dryer

Desi!n data

Alow rate of solid - 2::::.:> !gGhr

7ater removed - ,30.6!gGhr

8iameter -3.0m9ength - 1?.,2 m

olume - 133.1?36m3


115/148


116/148


) &ype of power supply. Botary positivedisplacement pumps and

centrifugal pumps are readily adapta'le for use with electricmotor or

internalcom'ustionengine drives5 reciprocating pumps can 'e used

with steam or gas drives.

6) *ost and mechanical efficiency of the pump.

:) &he amount of fluid that must 'e pumped. &his factor determines the

si/e of pump (or pumps) necessary.

>) &he properties of the fluid. &he density and the viscosity5 of the fluid

influence the power reuirement for a given set of operating

conditions corrosive properties of the fluid determine the accepta'le

materials of construction. If solid particles are suspended in the fluid

this factor dictates the amount of clearance necessary and may

eliminate the possi'ility of using certain types of pumps.

?) &he increase in pressure of the fluid due to the wor! input of the

pumps. &he head change across the pump is influenced 'y the inlet

and downstream reservoir pressures the change in vertical height of

the delivery line and frictional effects. &his factor is a maDor item in

determining the power reuirements.

10) &ype of flow distri'ution. If nonpulsating flow is reuired

certain types of pumps such as simple reciprocating pumps may 'e

unsatisfactory. #imilarly if operation is intermittent a selfpriming

pump may 'e desira'le and corrosion difficulties may 'e increased.

121


117/148


11) &ype of power supply. Botary positivedisplacement pumps and

centrifugal pumps are readily adapta'le for use with electricmotor or

internalcom'ustionengine drives5 reciprocating pumps can 'e used

with steam or gas drives.

12) *ost and mechanical efficiency of the pump.

122


118/148


"ump consists of two gear wheels which rotate inside a stationary

casing. @ecause the gear wheels rotate they are called the BC&CB# .and the

casing which remains stationary is called the #&&CB. 7hen the pump is

started up the liuid enters the pump through the liuid inlet1

and slugs ofliuid are caught 'etween the rotor and the stator and carried to the liuid outlet.

com'ination of the high speed of the rotors and the positive

displacement nature of this type of pump produces high pressurepumping.

CHARACTERISTICS OF THE GEAR PUMP(

=CC8 "CI


119/148

Chapter 10 In>tru


120/148

Chapter 10 In>tru


121/148

Chapter 10 In>tru


122/148

Chapter 10 In>tru to computer recorder 60.

12:


123/148

Chapter 10 In>tru

In the later there is a computation of the time average of the product of the flow

rate is multiplied to the rise in water temperature and an impulse corresponding to the

magnitude thereof is passed via line 62 to the let down pressure controller 63. *omputer

recorder 60 is connected via line :1 to a low temperature alarm. 7hen the signal from the

computer recorder is 'elow the previously set value.

t the start of each cycle each of various measuring devices is 'rought 'ac! to

/ero so as to start. t the start of ne4t continuous operation the outlet valve is reset to

give the operation pressure. "rovision is made for ma4. and minimum cycle times as well

as for ma4. pressures. &he operation may 'e com'ined with other control means e.g5 the

start up and shut down operations. &he operation may 'e controlled manually or 'y

means of an appropriate computer modification if desired.

12>


124/148

Chapter 11 H9OP !TUDY 130

HAZOP STUDY

Ha

can 'e applied to a whole plant a production unit or a piece of euipment It uses as its

data'ase the usual sort of plant and process information and relies on the Dudgment of

engineering and safety e4perts in the areas with which they are most familiar. &he end

result is therefore relia'le in terms of engineering and operational e4pectations 'ut it is

not uantitative and may not consider the conseuences of comple4 seuences of human

errors. &he o'Dectives of a +;C" study can 'e summari/ed as follows

1) &o identify (areas of the design that may possess a significant ha/ard potential.

2) &o identify and study features of the design that influence the pro'a'ility of a

ha/ardous incident occurring.

130


125/148

Chapter 11 H9OP !TUDY 131

3) &o familiari/e the study team with the design information availa'le.

,) &o ensure that a systematic study is made of the areas of significant ha/ard

potential.

) &o identify pertinent design information not currently availa'le to the team.

6) &o provide a mechanism for feed'ac! to the client of the study teams detailed

comments.

STEPS CONDUCTED IN HAZOP STUDY(1. #pecify the purpose o'Dective and scope of the study. &he purpose may 'e

the analysis of a yet to 'e 'uilt plant or a review of the ris! of une4isting unit.

=iven the purpose and the circumstances of the study the o'Dectives listed

a'ove can he made more specific. &he scope of the study is the 'oundaries of

the physical unit and also the range of events and varia'les considered. Aor

e4ample at one time +;C"s were mainly focused on fire and e4plosion

endpoints while now the scope usually includes to4ic release offensive odor

and environmental endpoints. &he initial esta'lishment of purpose

o'Dectives and scope is very important and should 'e precisely set down so

that it will 'e clear now and in the future what was and was not included in

the study. &hese decisions need to 'e made 'y an appropriate level of

responsi'le management.

2. #elect the +;C" study team. &he team leader should 'e s!illed in +;C"

and in interpersonal techniues to facilitate successful group interaction. s

many other e4perts should 'e included in the team to cover all aspects of

design operation process chemistry and safety. &he team leader should

instruct the team in the +;C" procedure and should emphasi/e that the end

o'Dective of a +;C" survey is ha/ard identification5 solutions to pro'lems

are a separate effort.

*ollect data. &heodore16 has listed the follow

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