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# OAR Box 1313 Prepped by LaTeia Shed



### Document

Number: 

# 67 ) ll-B-4 1

Docket Number: 

# A-88-0 2

Printed 6/12/20089:03:30AM

Sheet 67 of 99P. 2 

# MRI ® MIDWES T RESEARC H INSTITUT E Suit e C T A-88-0 2 " 0 1 Harnso n 0ak s Bouievar , Carv

. NC

. 27 ? 1

Date : Ma

y20 , 198 8 (Finalize dJun e 30 , 1988 ) Subject : Sit e Visit—Sac o Defens e Inc. , Saco , Main e

Chromium Electroplatin g NESHA P EP A Contrac t 68-02-3817 ; ES D Projec t 85/02 a MR I Projec t 7717- K
From : Rand y

Strai t
To : Andre w

Smit h ESD/ISB/SS S (MD-13 ) U . S . Environmenta l Protectio nAgenc y Researc hTriangl e Park , N.C . 2771 1

I . Purpos e Th e purpos e o f thi s sit e visi t wa s t o evaluat e the operatin g conditio no f th e singl e packed-be dhorizontal-flo w scrubbe r usedt o contro l chromium

emission s fro

m thre e har dchromiu

m platin g tanks . Th e scrubbe r i s bein g evaluate d a s a candidat e fo r conductin g emissio ntest s t o determin e th e exten t t o whic hcleanin g th e scrubbe r ca n improve scrubbe r performance . II . Plac e and Dat e
Sac o Defens e Inc . 29 1 Nort hStree t Saco , Main e 0407 2 Marc h31 , 198 8 (207 ) 283-361 1

III . Attendee s
Sac o Defens e Inc . Rober t Noonan , Senio r Environmenta l Enginee r Dual l Industries , Inc . RonDeFrenn , Fiel dRepresentativ e Midwes t Researc hInstitut e Randy Strai t

/P. 3

IV . Discussio n
I nMarc h1988 , plan t personne l hire d a nindustria l hygien e consultan t t o evaluat e th e ventilatio nrate s o nthre e hard chromiu m platin g tank s (identifie d a s Tank s 22 , 23 , and 24 ) tha t ar e controlle d b y th e singl e packed-be d scrubbe r bein g evaluate d fo r testing . Th e combine d de|ig nairflo w

rat e fo r th e thre e tank s is 3 34 0 cubi c meter s pe r minut e ( m /min ) (12,00 0 cubi c fee t pe r minut e [f t /min]) , o r 11 3 m /mi n (4,00 0 f t /min ) fo r eac htank . Th e surfac e are a o f eac htank i s 1. 5 squar e meter s (1 6 squar e feet) . Therefore , the 3 design 2 ventilat1g n rat e fo r eac htan k j s 7 6 m ,/nri npe r squar e mete r ( m /min/ m ) (25 0 ft/mi n pe r squar e foo t [f t /min/f t ] ) o f tank surfac e area . Result s o f th e ventilatio nstydy

indicate d tha t th e actua l ventilatio nrat e fo r eac htank wa s abou t 4 | m

/min/ m (16 ^ f t /min/f t ) an d th e actua l airflo w rat e wa s abou t 7 0 f t /mi n(2,56 0 f t /min) . Plan t personne l indicate d tha t th e lo w ventilatio nrate s fo r th e tank s ma y b e cause d b

y a makeu p ai r defici t i n th e plan t and/o r a decreas e i nth e operatin g performanc e o f th e scrubbe r fan . Therefore , plan t personne l requeste d Dual l Industries , Inc. , t o inspec t th e scrubbe r t o determin e i f th e scrubbe r wa s operatin g a t it s desig nspecifications . Mr . Ro nDeFrenn , Fiel d Representativ e fo r Dual l Industries , Inc. , (Duall ) measure d th e airflow rat e t o th e scrubbe r and visuall y inspecte d th e packe d bed , packin g media , wate r recirculatio nsystem , mis t eliminator , and fa no f th e scrubbe r t o determin e whethe r th e scrubbe r wa s operatin g accordin g t o desig nspecifications . Thi s repor t summarize s th e result s o f Mr . DeFrenn' s evaluatio no f th e scrubber . V . Result s
A . Airflo w

Rat e The 3 scrubbe r i s designe d fo r a nairflo w

rate ^ o f 34 0 cubi c meter s pe r minut e ( m

/min ) (12,00 0 cubi c fee t pe r minut e [f t /min]) . A pito t tub e wa s use d t o tak e a velocit y travers e i nth e ductwor k a t th e inle t o f th e scrubber . Th e ductwor k i s 0.6 1 m (2. 0 ft ) i ndiameter . Becaus e plan t personne l indicate d tha t the plan t wa s experiencin g a makeu p ai r deficit , a velocit y

travers e wa s take nwit hth e door s i nth e plan t close d an d anothe r travers e wa s take nwit hth e door s i nth e plan t opened . Th e airflo w velocit y

an d airflo w rat e measure d wit hth e plan t door s close d wa s 63 4 meter s pe r minut | (m/min ) (2,08 0 fee t pe r minut e [ft/min] ) an d 18 4 m /mi n(6,50 0 f t /min) , respectively . Th e airflo w velocit y

an d airflo w rat e measure d wit hth e plan t door s opene d wa s 67 0 m/mi n (2,20 0 ft/min ) an

d 19 8 m /mi n(7,00 0 f t /min) , respectively . B . Packe d Be d
Th e packe d be d i s 0. 3 m (1. 0 ft ) i ndepth , 1. 6 m (5. 3 ft ) inheight , an d 1. 7 m (5. 5 ft ) i nwidth . Th e desig nfac e velocit y o f th e airflow throughth e packe d be d i s 12 5 m/mi n(41 0 ft/min) . Th e frame o f th e packe d be d i s warped . Bot hside s o f th e frame ar e buckle d outwar d whic hha s allowe d th e packin g medi a t o settle , leavin g abou t 0.4 6 m (1. 5 ft ) o fP. 4

spac e betwee nth e topo f th e scrubbe r an dth e packin g media . Consequently , th e contaminate dai r passe s ove r th e to po f th e packin g media . Warpin g o f th e packed-be dfram e typicall y occur s whe nth e strand s o f polypropylen e tha t ti e th e wall s o f th e packe dbe dtogethe r brea k a s a resul t o f wear . C . Packin g Medi a Th e packin g medi a use di nth e packe dbe dwa s manufacture db y Protak . Th e packin g medi a i s mad e o f polypropylen e an dconsist s o f thre e concentri c ring s tha t form a sphere . Eac hspher e i s 6.3 5 centimeter s (2. 5 inches ) i ndiameter . Th e packin g medi a §as 3 a surfac e area-to-volum e rati o o f 12 8 squar e meter s pe r cubi c mete r ( m / m ) (3 9 squar e fee t pe r cubi c foo t [f t /f t ] ) an da voi dspac e o f 90. 6 percent . Mr . DeFren n indicate dtha t th e packin g medi a i s ver y dirty . A

thi nlaye r o f chromi c aci dresidu e ha s accumulate do nth e surfac e o f th e packin g media . Althoug hthi s typ e o f packin g medi a n o longe r i s manufactured , th e surfac e area-to-volume rati o an dpercen t voi dspac e i s simila r t o tha t fo r the Glitc hballas t ring s currentl y use db v Dyall . G]itc ^ ballas t ring s hav e a surfac e area-to-volume rati o o f 14 4 m /m (4 4 f t /f t ) an

da voi dspac e o f 9 1 percent . D . Wate r Recirculatio nSyste m Th e scrubbe r wa s designe dwit ha self-containe drecirculatio n system . Fou r spray

nozzle s ar e locate da t th e inle t o f th e scrubbe r upstream o f th e packe dbed . Fou r spra y nozzle s als o ar e locate dove r the to po f th e packe dbedt o allo w fo r continuou s floodin g o f th e packin g media . Th e desig nwate r flow rat e t o th e scrubbe r i s 13 2 liter s pe r minut e (3 5 gallon s pe r minute) . Currently , th e self-containe dwate r recirculatio nsystem i s disconnected . Wate r i s supplie d t o th e scrubbe r fro m a rins e tank locate d ne< t t o the chromiu

m platin g tanks . Th e scrubbe r wate r i s pumpe dfro m th e rins e tank , throughth e spra y nozzles , an

dthe ndraine dbac k t o th e rins e tank . Th e wate r lin e t o th e scrubbe r als o i s use dt o suppl y wate r t o a secondscrubber . Th e wate r pum pi s locate dnex t t o th e rins e tank . Th e rins e tank i s th e las t o f thre e rins e tank s use di na countercurren t rins e system . Th e chromi c aci dconcentratio no f th e rins e wate r tha t i s pumpe d t o th e scrubbe r i s 1. 1 gram s pe r lite r (0.1 5 ounc e pe r gallon) . Thre e o f fou r spra y

nozzle s a t th e inle t o f th e scrubbe r ar e partiall y

plugge dan

don e nozzl e i s broke nof f o f th e spra y header . No wate r i s supplie dt o th e fou r spra y nozzle s locate dove r th e to po f th e packe dbed . E . Mis t Eliminato r
A chevron-blad e mis t eliminato r wit ha singl e se t o f overlapping typ e blade s i s locate ddownstrea m o f th e packe dbed . Th e mis t eliminato r i s 0.2 0 m

(0.6 7 ft ) indepth , 1. 6 m (5. 3 ft ) i nheight , an d1. 6 m (5. 3 ft ) i nwidth . Th e desig nfac e velocit y o f th e airflow

throug hth e mis t



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eliminato r i s 13 0 m/mi n(43 0 ft/min) . Th e structura l integrit y o f th e mis t eliminato r appeare dt o b e sound . Non e o f th e blade s ha dcollapsed . However , ther e i s some buildu po f chromi c aci dresidu e o nth e blades . F . Fa n Th e fa n(Seria l No . 5615 ) i s designe dt o pul l 34 0 m 3 /nri n (12,00 0 f t /min ) o f air . I t i s a Typ e N H blower , Clas s II , Siz e 99 , wit h a stati c pressur e o f 1. 0 kilopascal s (4. 0 inche s o f wate r column) . Th e desig nspecification s o f th e fa nmoto r (Seria l No . 556591 ) ar e 1 5 horse power , 1,75 0 revolution s pe r minute , 40/2 0 amperes , 230/16 0 volts , an d 6 0 cycles . Th e fa nwhee l i s unbalance dan dth e fa nbelt s nee dt o b e replaced . Th e fa nwhee l i s coate dwit hchromi c aci dresidu e a s a resul t o f th e contaminate dai r bypassin g th e packin g media . A crac k i nth e fa nhousin g als o wil l nee dt o b e repaired . VI . Conclusion s Result s o f th e evaluatio nindicat e tha t th e scrubbe r i s i npoo r operatin g conditio nan dshoul dno t b e teste dunti l th e scrubbe r ha s bee n reconditione dt o operat e a t desig nspecifications . Th e lo w airflo w

rat e t o th e scrubbe r probabl y i s cause db

y th e poo r operatin g conditio no f th e fa nrathe r tha na makeu pai r defici t i nth e plan t becaus e th e differenc e i nth e airflow

rat e t o th e |crubbe r with 3 th e plan t door s close dan dth e plan t door s opene dwa s 1 4 m /mi n(50 0 f t /min) . Dual l recommend s th e followin g repair s t o th e scrubbe r befor e testing : 1 . Th e fa nwhee l shoul dbe cleane dan dbalanced , fa nbelt s replaced , bearing s greased , an dth e crac k i nth e fa nhousin g repaire dt o ensur e tha t th e scrubbe r i s operate da t th e desig nairflow rate ; 2 . Th e packed-be dframe shoul dbe restore dsuc htha t it s structura l integrit y

an ddimension s mee t desig nspecifications ; 3 . Th e remot e wate r recirculatio nsyste m fo r th e scrubbe r shoul dbe disconnecte dan

dth e self-containe drecirculatio nsystem shoul db e reconnecte dt o ensur e tha t al l spray nozzle s locate da t th e inle t o f th e scrubbe r an

dove r th e packe dbe dar e adequatel y supplie dwit hwater ; an d 4 . Ne w spra y header s an

dspra y nozzle s shoul db e installe dt o ensur e tha t th e scrubbe r i s operate da t th e desig nwate r flow rate . Th e cos t o f reconditionin g th e scrubbe r wil l b e abou t $4,000 . Afte r th e scrubbe r ha s bee nrestore dt o it s desig noperatin g condition , th e scrubbe r ca nb e teste dbefor e an dafte r th e scrubbe r i s cleane dt o determin e i f cleanin g ca nimprove scrubbe r performance . Cleanin g o f th e scrubbe r wil l involv e washin g al l chromi c aci dbuildu pfro m th e surfac e o f the packin g media , insid e walls , an dmis t eliminatio nsectio no f th e scrubber . Plan t personne l ar e restorin g th e scrubbe r t o it s desig n operatin g specification s an dwil l assis t i nthe cleanin g o f the scrubber .



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