Crystallizer Design

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Crystallizer

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Crystallization

•

• CrryyssttaC alllliizzaattiioonn iiss aann iimmppoorrttaanntt ooppeerraattiioonn iinn tthhee cchheemmiiccaall

iinndduussttrryy aass aa mmeetthhoodd ooff ppuurriiffiiccaattiioonn aanndd aass aa mmeetthhoodd oof f pr

provovididiningg crcryysstatallllininee mamattereriaialsls inin ththee dedesisirreded sisizzee rrananggee

•

• A pA prroocceessss wwhheerree ssoolliidd ppaarrttiicclleess aarree ffoorrmmeedd ffrroomm aa

hom

homogeogeneoneousus phaphase.se.

•

• It isIt is aa sosolilid-d-lliqiquuidid seseppararaatitionon prprococesesss

•

• Forr coFo contntroroll

1)

1) YYieieldld of of crystal’s crystal’s

2)

2) PuPurirityty of of crystal’s crystal’s

3)

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Theory of crystallization :

1)

1) SuSupeperr sasatuturraatitionon ofof ththee sosolulutitionon

a)

a) IItt ccaann bebe dodonnee bbyy tthrhreeee wwaayyss.. b)

b) HeHeatatiningg thethe sosolutlutioionn c)

c) CoCooliolingng ththee sosolulutitionon SaSaltltinging outout

2)

2) NucleationNucleation

Th

Thiiss ttakakeess plplacacee inin sesevvereralal sstteepsps.. D

Duurriinngg tthheeiirr rraannddoomm mmoottiioonn,, tthhee aattoommss// mmoolleeccuulleess// iioonnss wwiillll ccoommee cl

clososerer ttoo ononee ananototheherr anandd fforormmss agaggrgregegaatteses cacalllleedd asas CLCLUSUSTETERRS.S. T

Thheessee cclluusstteerrss wwiillll ccoommbbiinnee ttoo ffoorrmm aann EEMMBBRRYYOO.. IInn tthhiiss ssttaaggee oonnllyy tthhee lat

latticticee foformarmatiotionn begbeginsins.. This

This embryo’s embryo’s ccoommbbiinnee ttoo ffoorrmm NNUUCCLLEEII.. FFrroomm nnuucclleeii ccrryyssttaallss aarree formed

formed

3)

3) CryCryststalal GrGrowtowthh

O

Onnccee tthhee ccrryyssttaallss aarree ffoorrmmeedd,, nnuucclleeii ffoorrmmaattiioonn ssttooppss aanndd ccrryyssttaall gr

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Crystallization

The crystallization process consists of two major events: The crystallization process consists of two major events:

Nucleation Nucleation

Is the step where the solute molecules dispersed in

Is the step where the solute molecules dispersed in the solvent startthe solvent start together into clusters

together into clusters

The crystal growth The crystal growth

Is the

Is the subsesubsequenquent growt growth ofth of the nuclethe nuclei that succei that succeed in achieed in achieving theving the critical cluster size

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Crystallizer Design

Procedure

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Crystallizer Design

Procedur

e

The Following Step are outline for the Design of Crystallizer: The Following Step are outline for the Design of Crystallizer: 1)

1) Choose the type of crystallizer that must meet theChoose the type of crystallizer that must meet the requirement for

requirement for

a)

a) Product SizeProduct Size b)

b) Product QualityProduct Quality c)

c) Process economicsProcess economics

2)

2) Make a list of temp and physical properties required forMake a list of temp and physical properties required for calculation.

calculation. 3)

3) Make a Material balance, Heat balance and Flow sheet.Make a Material balance, Heat balance and Flow sheet. 4)

4) Decide what retention time is required to make the requiredDecide what retention time is required to make the required product.

product.

a)

a) By experienceBy experience b)

b) From growth and nucleation rateFrom growth and nucleation rate

Reference:

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Cont.…

5.

5. Size the body on the basis of controlling volume for crystalSize the body on the basis of controlling volume for crystal retention with due consideration for minimum cross-section retention with due consideration for minimum cross-section required for vapor release.

required for vapor release. 6.

6. Size the heat transfer surface.Size the heat transfer surface. 7.

7. Size the Vapor Pipe.Size the Vapor Pipe. 8.

8. Select the Circulate pump.Select the Circulate pump. 9.

9. Select Select the Agthe Agitatoritator..

Reference:

Handbook of Industrial Crystallization Handbook of Industrial Crystallization

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Crystallizer Designing

Parameters

1)

1) Retention timeRetention time 2)

2) Minimum Active VolumeMinimum Active Volume 3)

3) SizingSizing 4)

4) Height of CylinderHeight of Cylinder 5)

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Equipment Sizing:

Calculation Flow Diagram

Retention time Retention time   ==  3.67 3.67

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Equipment Sizing:

Calculation Flow Diagram

Minimum Active Volume Minimum Active Volume



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Equipment Sizing:

Calculation Flow Diagram

 __ = = __ Sizing Sizing  __ = = __ + + _{}_{}  __ = 0.1868 = 0.1868 ++  4 4  _(1.5)_(1.5)

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Equipment Sizing:

Calculation Flow Diagram

 __ = = __ Sizing Sizing  __ = = __ + + _{}_{}  __ = 0.1868 = 0.1868 ++  4 4  _(1.5)_(1.5) Height of Cone Height of Cone ℎ = ta ℎ = tann 5555(( 2 2 −− 0.1 0.1 2 2 )) Height of Cylinder Height of Cylinder ℎ = 1.5 ℎ = 1.5

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Mechanical Engineering Design

The selected material for the

The selected material for the crystalliz

crystallizer is (

er is (

stainless steel

316)

due to its

due to its high corrosion resist

high corrosion resistance.

ance.

•

Shell Thickness



__

= 

=



__







__   •

•

Tori spherical Head Thickness

 = 4

__







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Mechanical Engineering Design

•

Cone Thickness



__

=

= 



__









__   •

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Mechanical Engineering Design

•

Leg Support, Angle Type

 __ ==   [[  −− + + 66 ++        (−(− + + 66))  __ ==   [[  −− − − 66 ++        (−(− − − 66

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Mechanical Engineering Design

Figure A.5.4.5.Angle Leg Dimensions Figure A.5.4.5.Angle Leg Dimensions

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Swirl Breaker

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Pipe and Nozzle Sizing

To calculate the diameters of the pipe the following

equation is used.



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Importance of crystallization :

1)

1) Purification of drugs .Purification of drugs . 2)

2) Improve bio-availability of the drug and choose the mostImprove bio-availability of the drug and choose the most stable form.

stable form. 3)

3) A crystalline powder is easily handled ,stable , possessesA crystalline powder is easily handled ,stable , possesses good flow properties and an attractive appearance .

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Application of crystallization :

1)

1) PuPuririfificacatitionon ofof drdrugug 2)

2) BetBetteterr prproceocessissingng chachararactecterisristicticss 3)

3) EEasasee fforor hahandndlilingng 4)

4) ImpImprorovevedd phphysysicaicall ststabiabilitlityy 5)

5) SusSustaintaineded relreleaseease 6)

6) ImprImprovedoved bioabioavailvailabilabilityity 7)

7) PrPrepepararatatioionn ofof ororggananicic anandd ininororggananicic APAPII 8)

8) SeSepaparratatioionn ofof APAPII frfromom GaGaleleniniccalal eextxtrracactsts 9)