design considerations for wfi distillation systems part 2

7/25/2019 Design Considerations for WFI Distillation Systems Part 2

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Design Considerations for WFI

Distillation Systems Part 2ISPEApril 28, 2016 Design Considerations for WFI Distillation Systems Part 220160!

26"10#02#$6%00#00 &no'ledge, P(arma)e*ti)al Engineering +againe-o Comment

Design Considerations for Water for In.e)tion /WFI Distillation Systems for Improing

*ality, Pro.e)t Performan)e, and E3*ipment 4ife Cy)le Cost 5ed*)tion 'as feat*red

in t(e Septemer7)toer 201! iss*e of Pharmaceutical Engineering9 magaine:

"(is fo*rpart series presents and dis)*sses a n*mer of ;ey re3*irements and

design, 3*ality, and engineering )onsiderations t(at (ae (ig( importan)e in end*ser*saility, )ost )ontrol and endprod*)t 3*ality t(at (elp manage ris;s in Water for

In.e)tion prod*)tion and pro)esses: Part t'o reie's#

WFI (ot or )old loop or storage

"emperat*re of feed and )ooling 'ater

0 =C or (ot loop /80 =C or (ig(er, t(ere is a di?eren)e in t(e

energy )ons*mption and t(e sele)tion of t(e type of WFI prod*)tion e3*ipment: "(e

ene@t of a lo'temperat*re o*tp*t WFI system, s*)( as a apor )ompression

system, is lo'er energy )ons*mption: "(is type of system is not 'idely aailale for all

appli)ations: "(e (otloop and tan; WFI appli)ations ene@t from WFI s*pplied at an

already (ig(temperat*re o*tp*t of 8!=C or een (ig(er t(at is prod*)ed y m*ltiple

e?e)t distillation: 4o'temperat*re o*tp*t distillation systems are typi)ally intendedfor immediate *se 'it(o*t storage, and t(ese systems re3*ire periodi) sanitiation at

(ig( temperat*res to red*)e io*rden:

Establish a solid and realistic calculation for the equipment based on

realistic utility costs, performance values, and available quantities and

conditions. Always compare apples to apples.

"(e est 'ay to estimate t(ese *tility )osts is y )ooperating 'it( *tility design

engineers and end *sers of t(e e3*ipment: &no'ing t(e goal tr*ly (elps in ma;ing
http://blog.ispe.org/design-wfi-distillation-systems-part-2http://blog.ispe.org/design-wfi-distillation-systems-part-2http://blog.ispe.org/author/ispehttp://blog.ispe.org/design-wfi-distillation-systems-part-2http://blog.ispe.org/category/knowledge-resourceshttp://blog.ispe.org/category/pharmaceutical-engineering-magazinehttp://blog.ispe.org/design-wfi-distillation-systems-part-2#respondhttp://bit.ly/1SGspsmhttp://bit.ly/1SGspsmhttp://bit.ly/1SGspsmhttp://bit.ly/1SGspsmhttp://blog.ispe.org/author/ispehttp://blog.ispe.org/design-wfi-distillation-systems-part-2http://blog.ispe.org/category/knowledge-resourceshttp://blog.ispe.org/category/pharmaceutical-engineering-magazinehttp://blog.ispe.org/design-wfi-distillation-systems-part-2#respondhttp://bit.ly/1SGspsmhttp://blog.ispe.org/design-wfi-distillation-systems-part-2http://blog.ispe.org/design-wfi-distillation-systems-part-2


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t(e rig(t de)ision ao*t t(e type of e3*ipment needed for t(e fa)ility today and in t(e

eent of a f*t*re epansion: Be s*re to in)l*de t(e realisti) 'as(ing, )leaning, and

seri)e and maintenan)e )osts at realisti) interals: In addition to t(e r*nning )osts,

t(e seri)e )osts play a signi@)ant role in t(e entire life )y)le: "(ere is al'ays a ris; of

malf*n)tion '(en it )omes to )omple pro)esses and n*mero*s moing parts )riti)alpart maintenan)e and repla)ement )osts )an e signi@)ant, and prod*)tion do'ntime

is ery epensie:

Temperature of Feed Water and Cooling Water for WFI

Distillation Systems

For m*ltiplee?e)t *nits, feed'ater temperat*re (as a ma.or impa)t on t(e re3*ired

o' rates of )ooling 'ater: Additionally, it is re3*ired to )onsider t(e sie of (eate)(angers in order to 'or; 'it( (ig(ertemperat*re )ooling 'ater: For eample,

inlet temperat*res )an e *p to >!=C in so*t(ern regions )ompared to !=C to 10=C in

t(e nort(ern regions: "(e (ig(er inlet temperat*res of feed 'ater and )ooling 'ater

to t(e WFI system lead to a smaller temperat*re di?erential in t(e )ooling 'ater

aailale for (eat transfer: "(is impa)ts t(e o' rate of )ooling 'ater, as )older 'ater

(as more temperat*re di?erential: Its important to )onsider '(et(er t(e )ooling

'ater s*pply temperat*re (as seasonal ariations, as t(is may )a*se ot(er

)onsiderations for t(e )apaility of )ontrolling t(e pro)ess *nder di?erent )onditions:

+*ltiplee?e)t distillation systems need to e eal*ated to determine (o' many

e?e)ts are optimal for *tility *se as 'ell as t(e oerall energy )ons*mption of t(e

respe)tie apor )ompression system: Indiid*al and pro.e)tspe)i@) parameters

s(o*ld de@ne t(e most appropriate system: In)l*de t(e ro*ndtale reie' of t(e

entire life)y)le )ost of e3*ipment, '(i)( en)ompasses energy )ons*mption oer t(e

target operational life of e3*ipment /typi)ally 1! to 20 years, seri)e )osts, and

inestment )ost:

In todays 'orld of in)reasing energy )osts and s*stainaility )on)erns, it is adised to

loo; at m*ltiplee?e)t distillation *nits 'it( eno*g( )ol*mns, or any ot(er means of

(eat re)oery, to sae in (eating and )ooling'ater )osts: In an +WS, for eample, si

to eig(t e?e)ts typi)ally means t(at little to no )ooling 'ater is needed to prod*)e WFI

and sae t(e most in (eating )osts, as an in)reasing n*mer of e?e)ts signi@)antly

red*)es t(e )ons*mption of (eating steam:

How the WFI Distillation Systems Integrate with the Storage

Tank and Loop


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Comm*ni)ation signals et'een t(e WFI tan; and t(e distillation e3*ipment )an

proide a proportionally )ontrolled )apa)ity: "(is means t(at t(e distillation

e3*ipment )an a*tomati)ally ad.*st to t(e )*rrent demand of WFI )ons*mption

ased on t(e dire)t demand /leel of t(e WFI storage tan;: "o a)(iee proportional

)apa)ity )ontrol, t(e 'ater still needs to e e3*ipped 'it( a proportional )ontrol aleor ales for plant steam and feed'ater )ontrol, *tility meas*ring instr*mentation, as

'ell as a P4C )ontrol se3*en)e for r*nning t(e operation a*tomati)ally: Feed 'ater

)an also e )ontrolled y motor inerter )ontrol: Eliminating t(e starts and stops of

t(e WFI still also red*)es t(e time and energy spent on t(e r*nning *p, )ooling do'n,

or sanitiation period of t(e *nits as per t(e )*rrent )apa)ity needs: It may e di)*lt

to t(in; of t(ese saings in n*mers, *t t(ere is a 'ay# Simply eal*ate t(e n*mer

and d*ration of r*nning )y)les and pea;s of WFI )ons*mptions p*t in t(e simple

spreads(eet of a daily s)(ed*le: Instead of @e daily starts and stops, t(ere may only

e t'o, for eample, as t(e distillation )apa)ity is ad.*sted a))ording to )ons*mption:It is s*rprising (o' m*)( time, energy, and money )an e spent ann*ally on ramping

*p and do'n t(e system: It )an easily e proed t(at t(e paya); time of proportional

)apa)ity )ontrol t(at (as een implemented in a ne' or eisting WFI distillation *nit is

s(ort eno*g( to .*stify inestment: /See "ale A:


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By: Juha Mattile, Sr. Product Manager for Steris Finn-Aqua igh Purity !ater " #eam, $P

Sterili%ation and E&uent 'econtamination systems and Mi(e Par((a, Pro)ect Manager for

Steris Finn-Aqua

design considerations for wfi distillation systems part 2

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