C200-f00-L08-1dd

8/13/2019 C200-f00-L08-1dd

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Flow Sheets for Basic CHEN Unit Operations

Operations with Mass Transfer

1. DIVIDER/SPLITTER

a. The total balance is A!"#

b. #o$position of strea$s A% ! an& # is the sa$e for each.

c. There in onl' one in&epen&ent $aterial balance since all co$positions

are e()al.

*. MI+ER ,!len&er-

a. There are two or $ore enterin strea$s.

b. There is onl' one eit strea$% a 0$ie&0 strea$.

c. The strea$s can be an' phase% as% li()i& or soli&.

Splitter Feed, A

Splitter Exit 1, B

Splitter Exit 2, C

MIXER

Mixer Feed 2,B

Mixer Feed 1, F Mixer Product, E

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. DR2ER ,Direct 3eatin-

a. Sol4ent strea$ lea4es as a p)re 4apor an& is soli&s free.

b. Eit &rie& soli&s are in the soli& phase.

c. Drie& soli&s $a' not be sol4ent free.

&. 5ee& can be soli&% sl)rr' or sol)tion.

6. 5ILTER

a. 5iltrate% the eit li()i&% is soli&s free.

b. 5iltrate is sat)rate& with sol)ble co$ponent.c. The filter ca7e lea4es with so$e li()i& attache&.

&. #oncentration of strea$ E an& li()i& attache& to the filter ca7e is the

sa$e.

Dryer

Solvent, S

Dryer Feed, D Dried Product, E

Filter

Filter Cae

!et "olid", S

Feed Solution

or Slurry, D

Filtrate

#Exit $i%uid&, E

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8. DISTILLATIO9

a. The $ore 4olatile co$ponents are in the &istillate.

b. The less 4olatile co$ponents are in the botto$s.c. Separation is acco$plishe& b' boilin.

&. Perfect separation is not possible.

:. EVAPORATOR

a. Si$ilar to &r'in% ecept both process strea$s are li()i&s.

Di"tillation

Colu'n#ol)$n 5ee&% 5

Di"tillate, D

Botto'", B

Evaporator

Solvent, S

Evaporator Feed, D Dried Product, E

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;. DE3<MIDI5IER

a. 5ee& strea$ contains a con&ensable co$ponent an& a non=

con&ensable co$ponent.

b. #on&ensate is a li()i& with the con&ensable co$ponent onl'.

c. The 0&r' as0 eit strea$ is sat)rate& with the con&ensable

co$ponent at the T an& P of the process.

>. 3<MIDI5IER

a. The fee& as is not sat)rate&.

b. The li()i& is e4aporate& in the process )nit.

c. The 4apor eit pro&)ct $a' or $a' not be sat)rate&.

De(u'idi)ier

Conden"ate

li%uid, S

Feed *a"

Moi"t *a", DExit *a", E

+u'idi)ier

olatile Feed

li%uid, S

Feed *a" , DExit *a"

!etter -a", E

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?. @AS DR2ER

a. Sol4ent is transferre& fro$ li()i& phase to as phase.

b. <nit can be split into two )nits for anal'sis= a &irect &r'er ,as in -

an& a $ier of the fee& as an& the sol4ent $o4er to the as phase.

1. LEA#3I9@ B E+TRA#TIO9

a. The two li()i& sol4ents $)st be i$$iscible.

b. The' $)st ha4e &ifferent [email protected]. At least one co$ponent is transferre& fro$ one sol4ent to the

other b' &ifference in sol)bilit'.

&. The process is often calle& liquid-liquid extraction.

e. If one of the fee& strea$s is a soli&% the process is calle&

Leachin or li()i&=soli& etraction.

*a" Dryer

Dryer Feed, F

Feed *a", *Exit *a", E

Dry Product, P

Extraction

Colu'n

$i-(t Solvent Feed, F

+eavy Solvent Feed, *Extract $i%uid .ut, E

Ra))inate $i%uid .ut, R

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11. A!SORPTIO9 ,@as Absorption- ,DESORPTIO9-

a. P)rpose of )nit is to ha4e the li()i& absorb a co$ponent fro$ the fee&

as. An absorber is often calle& a scrubber.

b. The li()i& strea$ flows &own thro)h the tower b' ra4it'.

c. The as strea$ is p)$pe& )pwar&s thro)h the tower.

&. 9o carrier as is transferre& to the li()i&.

e. @enerall' no li()i& sol4ent is transferre& to the as strea$ ,chec7 this

ass)$ption-.

f. Desorption is the sa$e process as as absorption ecept that the

co$ponent transferre& lea4es the li()i& phase an& enters the as

phase. A &esorber is so$eti$es calle& a stripper.

A/"or/er

Dirty *a" Feed, F

Feed A/"or/in- $i%uid, *Clean Exit *a", E

Exit $i%uid, P

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1*. PARTIAL #O9DE9SER

a. The fee& strea$ contains onl' con&ensable 4apor co$ponents.

b. The eit strea$s% L an& V% are in e()ilibri)$.c. #on&ensation is ca)se& b' coolin an&/or increasin press)re.

1. 5lash VaporiCer% 5lash Distillation

a. Sa$e flow sheet as a partial con&enser ecept the fee& is a li()i&.

b. VaporiCation is ca)se& b' re&)cin the press)re an& /or heatin.

c. The Vapor an& li()i& strea$s are in e()ilibri)$.

Partial

Conden"er Vapor 5ee&% 5

apor Product,

Conden"ed $i%uid, $

Fla"(

0nit$i%uid Feed, F

apor Product,

$i%uid Producd, $

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1. #R2STALLIER

a. Soli& cr'stals are for$e& in the )nit b' a chane in te$perat)re.

b. The flow sheet for a cr'stalliCer is often shown as a co$bination

cr'stalliCer=filter.

18. REA#TOR ,#he$ical Reactor% co$b)stor% f)rnace% refor$er-

a. The &iara$ shown is for a t'pical reactor that has two reactant fee&

strea$s an& a rec'cle strea$.

b. If a sinle reaction ta7es place% p)t the con4ersion in the bo.

c. A reactor is often na$e& b' the reaction ta7in place.&. A reactor is so$eti$es prece&e& b' a fictitio)s $ier if the co$bine&

reactor fee& is specifie& or $)st be &eter$ine&.

e. M)ltiple eit strea$s are shown to re$in& 'o) to watch for eit

strea$s that separate beca)se of their &ifferent phases.

Cry"tallier

Cry"tallier Feed, C Slurry Product, E

Reactor

Recycle Feed, R

*a" Product", *

Reactant 1 Feed, A

Solid Product", S

Reactant 2 Feed, B $i%uid Product", $

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