BY: Yorrvn Plakr Particulate Technology Branch f i r and Energy kginrcring hiearch hboratory U.S. Environmental Protection Agency &8e8rCh Triangle Park, N.C. 27711

Prerented a t tbc Second U.5.-Dutch International Sy8porim: Aero8018 yil l iauburg, Virginia

b y 19-14, 1985

I ii

R. Plaks

NEW IZCRNOLOCP Pok TBE CONTROL OF AEROSOLS PRm STATIONARY SOUBCES

by: b r ” n PlritO Pa r t i cu la t e Technology Branch lrir md Eaergy

Engineering Rerearch Laboratory U. S. h r i r o m e n t a l

Protection Agency Research Triangle Park, R.C. 27711

ABSTBACT

The Environmental R o t c c t i o n h e n c y bar uadenay 8 prop- t o develop

new technologier f o r cont ro l l ing pa r t i cu la t e u t t e r from r t a t i o r u r y rourcer,

including both e l e c t r o r t a t i c r l l y augmnted f a b r i c f i l t r a t i o n (ESFF) and

c l e c t r o r t a t i c prec ip i ta tor8 (ESPr).

vhich usee an e l e c t r o c t a t l c f i e l d p a r a l l e l t o the fbb r i c rurface, provider

a reduction i n prcrrure drop t o about SOX of the prerrure drop in conventional

f a b r i c f i l t r a t i o n for both reverre-air and pulre-jet operation.

generation (or Super) ESFF, vhich u t i l i z e r an e l e c t r o r t a t i c f i e l d

perpendicular t o the f a b r i c surface, provider reductions in pressure drop

The first generation ESFF system,

Second

t o 10 to 30%.

penetrat ion by up t o a f ac to r of 4 as compared u i t h convention81 8-11

diameter corona electrodes.

U r g e diameter corona e lec t rodes i k ESPs have decreaced the

Uork on the m l t i r t a g e ESP has shown t h a t ,

f o r Ugh reristivity parz i tu l8 te matter, It i r posrfble t o Conrtroct an

ESP that provider perforvntr equivalent t o 8 c o n v e n t i p l ESP 4 t o 5

t i r c r l a rger . The L-SOX tecbaology u t i l i z e r the u l t l r t a g e technology t o

. free up apace within an a x i 8 t i D g ESP for s u l f u r dioxide removal of 60 t o

90%, by i n j ec t ion of .uU* n a g e n t r .

techniquer are 8llowing rm rrpid 8nd econoriccrl ESP derlgnr.

Iaproved computer modeling

I

NEW TECHNOLOGY FOR THE CONTROL OF AEROSOLS PROM STAIIONABP SOURCES

XMgODUCTION

As p a r t of its l i rr ion the EDVirOrt#ntd R o t e c t i o n b e n c y undertakes

research t o develop pol lut ion control technology for . idlag industry in

meeting the requirements of the variour alr pol lu t ion control r tandards

and regulationo.

pa r t i cu la t e matter control technology.

number of r i g n l f i u n t advances i n both f a b r i c f i l t r a t i o n and e l ec t roo ta t i c

p r e c i p l t a t i o n ~ ~ r c v e r a l of which are deccribed in t h i s paper,

Part of t h io r e r t a rch and developocnt is in the area of

Out of this program has come a

FABRIC PILTBATION

Elistoricallp, f a b r i c f i l t r a t i o n has been used f o r a conriderable

time in industry. Fabric f i l t r a t i o n i r ' b e i n g applied -re frequently t o

u t i l i t y and i n d u s t r i a l bo i l e r pa r t i cu la t e u t t e r control w i t h increasing

use of l o w s u l f u r coals having high r e r i r r t i v i ty f l y arhes.

In the EPA pa r t i cu la t e program i t has k e n concluded t h a t , of a l l

the parameters involved i n f a b r i c f i l t r a t i o n deeign, electrortatics, when

properly applied, i r the domlrunt. s:

~ ~ c c t r o r t a t i c a ~ ~ y augmented f a b r i c f l l t r a t i a n (ESFP) i r a technique

ln rhich an electrortatic f i e l d ir er tab l i rhed acr088 the f a b r i c t o cause

p re fe ren t i a l deposit ion of the pa r t i cu la t e u t t e r on rcme aream while

leaving other areas open t o gas flow. The e l e c t r o r t a t i c f i e l d ac t ing on

charges upon the pa r t i c l e8 u u r e r t he r e l e c t i v e deposition; t he 8tronger

L 1. Plaks

the charge and electric f i e l d the greater i r the ESPF ef fec t .

a r e a caures 8 lawered prerrure drop f o r the bghoure.

date has been w i t h the electric f i e l d parallel t o the rurface of t h e

The open

Much of the work t o ~

fabr ic . Typically the f i e l d Val generated between electrodes, placed a t

the rur face of the f ab r i c , running the length of the bag, and pl8ctd about

2 em apart . The e l e c t r i c f i e l d r t r e g t h l r from about 2 t o 8 kV/cm. In

pulre-jet operation (in which the p a r t i c l e u t t e r lr col lected on the

ou t r ide of the bags) the U l r t aupport cage i r adapted for developing t h e

e lectr ic f i e l d a8 rhovn in Figure 1. IdjaCmtt virer are lnru la ted from

each other thereby allowing the cage i tsel f t o be e l e c t r i f i e d . For

reverrc-&Ir, which doer not we a a p e , and in whlch t h e p a r t i c l e matter

l r col lected on the bag I n t e r i o r , r t r i n l e r r steel yarns have h e n woven L.

into the f a b r i c warp an rhown l n Figure 2. The f a b r i c l r f iberg lass w i t h

a Teflon f i d 8 h ; t he y8m i r 316L r t a i n l e c r r t c c l h8ving 90 fibers each

22 m i n diameter (2).

betveen them, the a8me a0 In pulre-jet.

- The alternate yam8 have t h e electric f i e l d developed

The LSFF e f f e c t ha8 been rhom f o r f l y arhe8 on -11 EPA in-hourc

baghouaer a t Rerearch Triangle P8rk, NC. It b r a180 k e n r h m f o r both

+everre-air and pulse-jet u l t h the EPA 28 ac tua l d / m l n p i l o t unlt having

2.4 8 b g r on an l n d u r t r l a l boiler at the RiPorrt MayneAoro, VA, f a c i l i t i e s .

An ESPF ryrtem ha8 been operated f o r about 14 moatha, wing r rverre-air ,

at t h e tPA 140 actwl r3/mln p i l o t tanit at the hthwert Public Service

Barrington Pauer S ta t ion i n Amrfllo, TX. At the Earrington p e r plant

the b g r =re f u l l u t i l l t p aitt, each k i n g 9.14 long rod 0.3 8 In diucter

~ p i c 8 l l p , for f l y 8rh the prerrure 'drop acrorr an ESFF bghoure i s

.bout 50% of t h e prerrure drop 8cr088 8 convention81 bghoure (1,3).

~ 8 n r that one can minimize the p r r r ru re drop urd cormequentlp tbe fan

This

power or elae decrc8re t h e number of b8gr .nd coarequcntly t h e c a p i t a l

A rerier of experiments e r e performed on the EPA in-haure hghoures

f o r both reverre-8.ir and pulre-jet w i n g redirperred p r r t i cu l8 t e u t t e r

from a rpray drying process for 8ulfur dioxide capture. In rpray drying,

8 lime r l u r r y f r in jec ted I n t o a -her t o react wtth the ru l fu r dioxide.

The r e su l t i ng d x t u r e comirtr of f l y 88h, 8nd re8cted and unre8cted l i m e .

For rpray drping by-product pa r t i cu la t e u t t e r , t h e prerrure drop vas

reduced by .bout 8 f8c tor of 4 t o 6 8 s compared t o conventional f i l t r a t i o n .

Figure 3 l o 8 prer rure vs time tr8ce which 8h-8 drupr t i ca l ly the e f f e c t s

of turning the f i e l d on. A t the rtart, with the power o f f , t h e pressure

drop wa8 continuing to rire and vould have eventually gone off the chart

if contimed. The prerrure drop rt8rted t o respond l ~ d l 8 t a l y t o turnlng

on the f i e l d .

The ESFF e f f e c t that h8r been dircursed 18 b88d upon the ac t ion of

8n electric f i e l d upon particulate u t t e r containing only natural charge.

No corona for ch8rging the p8rtIcler m a gener8ted. The w u u r e d n8tur.l 4

. Ch8rge On tfpid f l y 88h $8 8 h t 0.1 t o 0.2 C/g; for 8pr.J drying

byproduct 0- of the r a r u r e d ch8rger were 88 high 80 1.68 c/g.

di f fe rence l a the prer rurc drop reduction for 8pr.y drylng u t e r i d 88

comp8red t o f l y 8rh acc~ulltr f o r ~ O I Y of the improvement.

The

The remainder

IJ. P l 8 k s

l r due t o the a b l l l t y f o r developing a rtronger e l e c t r i c f i e l d w i t h t h i s

material as a r o u l t of lower operating temperaturea and higher r o i r t u r e

lerelr.

drop reduction.

and decrcarcs v i t h lowered e l e c t r i c f i e l d .

Varying the e l e c t i c f i e l d h.r a h 0 been reen t o a f f e c t the praroure

The ESFP e f f e c t improver w i t h increasing electric f i e l d

Work I 8 underuay on t tchniquer l a ESFF f o r rimultaneourlp increasing

the f i e l d r t r eng th and fncrear ing the charge on the partlcler.

good indlca t lon that by doing chi6 i t would be pors ib l t t o achieve prcsrure

drop reduction f o r wit pa r t i cu la t e matter t h a t w i l l equal t h a t vhich vas

achieved w i t h rprap drying uttr ia l .

There 1s

Charging of par t ic feu occur8 when a Corona current i r u u r e d to flow

acroas the gar rtream containing the p a r t i c l e r .

which the t l t c t r o d e r and r e s u l t a n t electric f i e l d a r t p a r a l l e l to t h e

ru t f ace of the f a b r i c , i r not conducive t o generation of a corona discharge

or increar ing the f i e l d r t rength ; the f i l t r a t f o n f a b r i c would rapidly

break down f r o 8 the corona formed on i t 8 ~ u r f a c e .

p a r t i c l e s 8nd to lncreaoc the f i e l d r t r eng th has l ed t o a recond generation

ESFF which has been t amed 'Super ESFF."

f i e l d , v i t h corona d i a d u r g c , i o developed perptndlculat t o the f a b r i c

r a t h e r than parallel. Super tSFF has been applied t o both revtrre-air

and pulrc-jet ffltration.

Conventional ESFF, in

The need t o charge the

I n Super ESFF a r t rong e l e c t r i c

c

In reverre-air Super tSFF t he electrical f i e l d i o developed between

an Uta11 loc8ted wire, extending the length of the bag, and the i n t e r i o r

8urfacc of the fabric f i l t r a t i o n bag which l r "de e l e c t t i c c r f l ~ conduccloc

by one of revera1 man8 (&e ?igure 4). 'The electrical f i e l d between the

u r ia l r i re and the grounded conductive f a b r i c i o r u f f i c e n t l y rtrong 80

that the a r e gocr i n t o corona, and t he particle8 enter ing the bottom of

the bag, containing r o w na tu ra l charge, are given addi t iona l charge by

the corona cur ren t< In nom1 f a b r i c f i l t r a t i o n the particles follow the

8.8 r t r e d i n e r and conrequently tend t o depor i t themmlver evenly on the

bag's i n t e r i o r .

p a r t i c l c r leave the gar r t re .n l iner and tend t o be r e l ec t ive ly deporited

on the lover portion of the bag.

v i t h l l t t l e or no particle matter upon t h e rurface.

majority of th9 gar flovo out through the upper portion of the bag vhich

provide6 A r ign i f i can t ly decreared prer rure drop.

Under the inf luence of the electric f i e l d tbe charged

This leave8 the upper port ion of the bag

Conrcquently the

Pulre-jet Supcr ESPP require6 that the e l e c t r i c f i e l d be perpendicular

t o the external rur face of the f a b r i c f i l t r a t i o n bag, which is the rur face

upon vhlch the particle u t t e r co l l ec t r . Ibis $8 accorplirhed by developing

the electric f i e l d k t u e e n corona dlrcharge wirer, placed p a r a l l e l between

the f a b r i c f i l t r a t i o n h g s , and the vire . n t i r o l l a p r e cage8 inside of the

b g r ; the u g e r in t u rn are grounded (ree Figure 5). The s t ronges t e l e c t r i c

f i e l d i r e r t ab l i rhed in the area d i r e c t l y between t he wire and the grounded

.Upport age .

mtter l r 8 c l e c t i n l y deporited.

between t he re area. of madrun depor i t provide the law flaw r e r i r t a n c e f o r

the u j o r i t y of the gar which rerultr in the lovered p t e r ru re drop acrors

ft i r in thir 8rea that the "xi" &t of particle

The f a b r i c f i l t r a t i o n bag rur facer

tb. -8.

The r n e r r n i r Super LSFP b.0 been operated in a -11 riagle-bag

baghourc with b8gs 1.07 in length and 0.13 m and 0.2 i n diameter.

prerrure drop ranged from about 10 t o 3OX'of tbe prerrure drop of conventional

The

rever re-a i r f i l t r a t i o n . The range ir function of particle matter

r s s l r t l v l t p and gar temperature.

rtrengthm. Lmcr r e ~ i r t f v i t i e a allow higher corona currentr .

Laver temperaturea allw higher f i e l d

With high

f i e l d t t r eng th 8t a temper8ture of about 70% and uxi" ch8rge (much 86

experienced w i t h rpray dryer cooditlonr) the prerrure drop I8 lowest. A t

hfgher temperature8 of about 150%. 81 experienced under the gas cleaning

coadi t lonr of rte.m=electric u t i l l t i e r , especially v i t h high r c r l r t l v l t y

particle matter, t h e pressure drop was a t the bigher end of t h e range.

& a l a rge r reverse-air Super ESFF p i l o t un i t having 0.2 diameter

bags, 7.47 m in length, operating on a 8toker-fired boi le r a t lSO'C, t h e

8vcr8ge prerrure drop ua6 .bout 25% of the prerrure drop k i n g achieved

wi th conventional f 8 b r i c f f l t r r t i o n . 'Ihe fly 8rh from t h i r r toker-fired

boi le r had 8 very lor electrical r e s l a t i v i t y due t o about 301 unburned

carbon contained withfn it. Performance from rcversc-8lr Super ESFF

appears t o offer a r lgn i f i can t improvement over the o r ig ina l ESFF concept

d r r c r i k d previourly, and offers an even grea ter improvement over

conventional r tvcr re -a i r f i l t r a t i o n .

r igaif icrrnt reduction i n oper8ting c08ts due t o the ne& for l e s e fan

p e r , or %err c a p i t a l cortr due t o the need f o r even fever f i l t e r b g s

a0 compared t o conventional ESFF.

Thir again will 8110~ either a more

A -11 m u n t of rork har been done on pulrc-jet Super ZSFF. A

nine bag ambient temperature baghoure b v i n g bagr 1.22 8 In length 8nd

0.13 I In diameter uam electrified. Dif f icu l ty i n r t 8 b l l I r i n g the

I ' 7

1. Pl&c

r e r l r t i v i t y of the p a r t i c l e u t t e r made a quan t i t a t ive determlMtion of

the prer rure drop reduction urrfearible. However, the data qua l i t a t ive ly

idicater that t h e prer rure drop reduction i r r i g a i f i c a n t l y improved over

the conventional pulre-jet ESFF prevlourly d e r c r i k d . Pulre-jet Super

ESFF rhaur coamiderable po ten t i a l , and addi t iona l work i r rcheduled.

ELECTROSTATIC PRECIPIlLLTOBS

EPA'r e l e c t r o r t a t i c p r e d p i t a t o r (ESP) research has concentrated on

improving performance and operat ion, decreasing rite and c o l t , upgrading

performance f o r operation w i t h desu l fur iza t ion ryitem6, ln tegr8 t ing r u l f u r

dioxlde c o n t r o l I n t o the ESP, end developing performance 8nd cost models.

H i s to r i ca l ly , f o r operat ion with low r e s i s t i v i t y p a r t i c l e matter,

ESP6 have been designed f o r high corona currents . Even with there high

corona current6 the abrence of a back corona problem allow achievement of

high electric f i e l d r t rength. Aa a conrequence, the ESP0 operated w e l l ,

and the particlcr were e a r i l y charged and col lected. U g h corona cur ren ts

were achieved by ure of "11 diameter dlrcharge wirer (approximately 0.3

cm) o r uae of e lcc t roder with a m u l t l p l i d t y of d i s c r e t e discharge points.

Uhere the allowable u re fu l cur ren t i r l iml ted by high r e r i r t i v i t y , the low

corona onmet vol tage and f a i r l y r t e e p vol tage/current &la t ion rh lp rerult

in both a decrearcd electric f i e l d r t r eng th and low corona cur ren t f o r

charging. The combinatloo of low curren t den r i ty 8nd electric f i e l d produced

by conventional dlrcbrge electroden r cqu i r e r that a high r p e d f l c co l l ec to r

&rea (Sa) be provided t o r e t e a l 8 8 i O l l mtandardr. fbe SCA i r defined 88

the r a t i o of the volumetrfc flow r a t e of gas t o the co l l ec to r p l a t e area.

8 1. Pl8ks

Experircntal r t ud ie r the EpA 8 6 0 " a c t d m3fmln f i e l d p i l o t uni t a t

mA'8 B u l l Pun Pover Plant and the in-houre 28 actual r3/mln p i l o t ESP have

rhom that the u re of la rger dl-tcr. m o t h - r u r f a c e electrodes

(approdmately 1 cm i n diameter) u n provide 8 rignlflont lmprorement in

ESP p e r f o r u n c r - t r p e c i & l l y when high r e r i r t i v l t y particle u t t e r l r

col lected, The l a rge diameter e lectrodes .Ilw operation a t Ugh f l t l d

r t rengthr and urefu l Current d c n r i t i e r f o r particle charging. A8 a n be

reen f rou Table 1. t he la rge diameter vires reduce t h e penetration f o r

high r e r i r t i v l t y p a r t i c l e Ut te r (2 x l0l2 ohm-em) by a fac tor of 6 , and

the penetration f o r moderate r e r i r t i v l t y (8 x 1010 ohm-cm) particle

matter r e r i r t l v l t y by a f&ctor of 1.25. Economlc a ~ . l y r i o h.0 rhown t h a t

t he large diameter wire technology i r applicable i n b o t h new and r e t r o f i t

o i tua t ions when the particle mtter r e r i r t i v l t y ir grea ter than about 8 I

1010 o t " . The appl icat ion of t h i s technology is being fu r the r purrued.

In c o n v e n t i o d ESPc p a r t i c l e charging and co l lec t ion take p h c e in

the 8- electrical rectioc. It har been found that, f o r the higher

r e s i r t i v l t p particle matter, r e p ~ r a t i o n and optimlration of the charging

and co l lec t ion rtepo can lead t o r ign i f i can t improvements In performance.

A nuakr of precharger technique have been workcd.upon including

the t r l e l e c t r o d e (4). cold-pipe (5). .ad charged droplet. -

One of the

*mort prumlring i r the cold-pipc predmrger m h m i n ?igure 6. It C O n t i r t 8

of dimcharge virem in te r rper red with grounded piper through vhich cooling

water flwr.

atre- but t o cool t he du r t l ayer t h a t f o r u on the piper.

The purpore of the cooling rater i r not t o cool the gar

Cooling the

I ' 9

1. Plrks

dur t l aye r decrearer the r e r i r t i v i t J , thereby a l l w i n g high f i e l d r t rength

8nd a r r e n t which put8 high charge h v e l r on the prt ic ler . The direcfion

of gar flaw f o r t h e f r o n t d e w Of the cold-pipe p r e c h r g e r , which l r on the

l e f t ride 'of the f igu re , l r perpendicular i n t o the paper; f o r the r i d e

r i e v the gar flaw i r from l e f t t o right. -

Combining the cold-pipe precharger r i t h v i r e - p l a t e co l l ec to r r using

l a rge d i u c t e r vires provider an even f u r t h e r i r p r o v m n t in perforunce .

Large diameter vires in the co l l ec to r rec t ionr all- development of Ugh

f i e l d r t rengthr and a180 provide r u f f i c i e n t corona current t o clamp the

particle l aye r t o the p l a t e r , thereby minimizing non-rapping reentraiament.

p a r t i c u l a t e v t t c r a mil t ia tage ESP vi11 give the ramt col lec t ion e f f ic iency

88 8 conventionrl ESP Operating with r e lg t ive ly l o w current8 and f i e l d s

and having 4 or 5 t h e 8 the co l i ec t lng p l a t e are.. Operation of t h e

d t i r t a g e ESP v i t h the cold-pipe p r e c h r g e r and l a r g e diameter wirer in

the c o l l e c t o r mectionr h.8 been done on the EPA irrhoure 28 actu8l r3 /r in

ESP .rut on the EPA 425 ac tua l r3/m1n ESP a t ~ o t o r a d o Publ ic ~ e r v i c c ' r

Valmont Power Stat ion.

i

Xul t i r tag ing , uhen r e t r o f i t t e d t o an ESP that i r rorldrig w e l l and i s

..in compliance r i c h the particulate matter regulatimr, rill have -re

u p 8 d t y than 10 ac tua l ly needed. l'hir n y g e r t r that r o y port ion of the

ESP i n t e n u l r can be removed. 'Ibir f reed up rpace, f i t t e d v l t h r u i t a b l c

nOtt1e8, can be umcd f o r removal of r u l f u r d lor ide from a f l u e g u by

I

I

i n j e c t i n g droplet8 of an a lka l ine reagent.

I

Thio rystem, rh i ch ha8 been m d E-SOX, f o r the removal of ru l fu r

d i o r i d t along with t h e pa r t i cu la t e u t t e r in an ESP, 1s ohom r c b e u t i u l l p

In Figure 8.

lime that t u 8 been rlaked and r l u r r i e d by techniques t h a t lure been

developed fo r conventional rpray drying flue gar deru l fur i ta t ion ,

ThC alkali reagent riaon! being orad here i r high ulcium

&SOX

1s dircursed l a conriderably g rea t e r d e t a i l elsewhere (a), (7).

The E-SOX ryrtem h88 been evaluated 00 t he In-houre 28 a c t u a l r3/mln

ESP uring tvo-fluid noztler f o r the alkali reagent inject ions.

dioxide removal r e s u l t s are rhowrr in Figure 9.

The ru l fu r

Ybo reagents were used-

rodium carbonate so lu t ion and lire r lu r ry , With the rodium carbonate

i n l e t concentration8 of 15 and 30% by weight and a t flow rates ranging

from 26 t o 75 liters per hour, the ru l fu r dioxide removal ranged, f o r an

I n l e t concentration of 1200 t o 1500 ppm, from about 50 t o a h s t 90%,

h t h 2 mcondc of reridence time. With a r lu r r i ed lime in jec t ion , whore

concentration was 7 and 15% by.tnight, SO2 removal ranged from about 60

t o 8lmort 60%.

ratel.

Muimxm r u l f u r diorride w.6 removed a t the higher i n j ec t ion

The removal vas not found t o be highly renritive t o reagent

concentration. For the lime experiments the maxi- r t o l c h i o w t r y of

calcim t o ru l fu r was about 1.8 based upon i n l e t ru l fu r dioxide.

carer the i n j ec t ed droplet8 were completely dr ied i n c&sidcrably lcsr

than 2 recondr, and the depor i t r on the ESP were removed by normal

In both

r8pplng. la t h i r rerlsr of experiment8 no attempt -8 u d e to optimize

the m l f u r dioxide removal. In a typica l ESP r e t r o f i t , enough of the

iatemalr could be removed to obtain 2 recondr of rcridcnce time.

r r u i a d e r of the ESP e m be r u l t i r t a g e d not only t o regain orl&lnrl

par t i cu la t e co l lec t ion pcrforvnce but a h 0 t o capture the injected

The

I -

reagen t

--

The cortr of &SOX have not been f u l l y worked out, Emever, i t 18

expected that the procerr rhould be m n g the larnrt coat of the ra r lour

f l u e gar d e r u l f u r i u t l o n techniquer.

onn.cerrary t o add equipment, 8Uch 88 8 rpray drying chamber, f o r r u l f u r

the w e of an e x i r t f n g ESP v k e r It

dioxide u p t u r e ; the lime 878ta 18 the "e 88 l a required for 80me of

the other procerrer.

l a rge quant i ty of droplet8 lwerr the gar temperature and volume vhich

Orrc 8dv8ntage of &SOX I s that the In j ec t ion of a

c.ures a reduction In particle r e r l r t l v l t y urd an Increme In SCA. The

E-SOX projec t I 8 expected t o be mowed onto a l a r g e r p i l o t u n i t uring actual

f l u e gas a8 the next r t age In It8 developunt .

E-SOX, If 8uccerrfully developed, uould be a 1 0 I ~ C 0 8 t r e t r o f i t f o r

reducing a l r r i o n r of r u l f u r dioxide from coal - f i red power plmtr. Thir

I s r lga l f l c8n t f o r r eve ra l reuonr: f l r~r t , coal-fired power plants wi th

ESP particulate cont ro l technology reprerent the l a r g e r t rource category

f o r r u l f u r d l o d d e Lli8810n8 la the U.S.; and recond, t he high c o r t of

cont ro l l ing r u l f u r dioxide wlth e x l r t l n g technology l a a major l r r u e t o be

conrldered In air pol lu t ion policy a a ~ l y r l r , It uould k e rpec ia l ly urefu l

f o r thore r l t u a t l o n , In which there i r not room f o r r e u o f l t of a rpray

drying f l u e gar de ru l fu r l r a t lon cb.rkr. c

OTEER ACTIVITIES

fo 8ddl t lon t o the uork j u r t d e r c r l k d , EPA ha8 a r t rong program In

modeling a d fundamentah,

program i r t o pror lde drriga and p e r f o r u n c e modelr. f o r the pa r t i cu la t e

Tbe pupore of the modeling/fuad.wntalr

con t ro l d C d C C 8 , rbich are b r e d on rouad a d e r r t a n d i n g of the underlying -

1L N. P1&8

physics of the p8r t icu la tc co l lec t ion procero.

in a computer model t h a t is i n rfdespread appl icat ion by wendorr, users ,

8nd rerearcherr (81, eepec ia l ly for u t i l i t y 8pplic8tionr. Uork i r mdervay

t o Improve t h e ESP model in the .rea@ of e f f ec t8 of e lectrode geometry,

The ESP work has resulted

electrical conditfonr, 8nd 8p8Ce c b r g e .

applying the ESP model t o Induet r ia l sources In addi t ion t o u t i l i t l e r .

A new modelling technique computes the voltage and current for 8cveral

mere 18 8180 i n t e r e r t in

common electrode geoaetrier. The r e s u l t s are prerentcd both numericdly

8nd a8 a video d i rp lay of the electric f i e l d 8nd the current d i r t r ibu t ion .

The a b i l i t y t o dirplay the electrode geometry, e l e c t r i c f i e l d s , 8nd

current d i r t r i b u t i o n allow8 the derigner t o u k t changes and %mediately

detennioe t h e e f f e c t of the changes on ESP performance. Work i s current ly

underway t o extend and ver i fy the model c8pab i l i t i e s t o al l electrode

8haper and t o a l s o 8llw changes i n col lec tor geometry.

The p rop- has produced i ‘ u r t f u l k d e l f o r f ab r i c f i l t e r s . The

current vers ion of the model doer not include e l e c t r o s t a t i c e f f ec t s .

Eowever, uork i r wdemray t o Introduce the e f f e c t s of appl icat ion of ESFF

i n t o the f a b r i c f i l t r a t i o n modelo. A major e f f o r t ir underway t o extend

the wtfulners of there rode18 t o the control of particulate matter from

va r l a r8 i n d u r t r i a l OOU~CCI i n 8ddi t lon t o o t i l i t i e o . 6

I There l e addi t iona l rork king done i n fug i t ive particle control

involoirrg the development of engineering derlgn Infomation for hoods

used for collection of particles and fum. Operation rad maintenance

Umd8 8re king developed for ESP8 and b8gbo~D.8. Piu8119, te8Urch i s

belag done t o develop technology t o dccreare tbe emirriour of conden8iblc

aerosolr .

13 w. Plakr

CONCLUSION

Thir paper has prerented an overvlrw of the key project8 of the t P A

particulate technology R6D program, r h i c h u y be of laterert t o industry.

Work Vi11 be continping In the area8 that include ESPr, e l e c t r o 8 t a t i c r l l p

a u g m t e d f a b r i c f i l t r a t i o n , and cont ro l of f u g i t i v e e m l r r i o ~ . Dl8curaion

of rpecifsc problem in par t i cu la t e u t t e r cont ro l that may W e u8e of

the re technology are.), would be u r l c a a d .

REFERENCES

1.

2.

VaaO8del1, D.W., hnadc, M.B., Creiaer, C.P., and Furlong, D.A.

'E lecror ta t lc dugncntatlon of Fabric F i l t r a t i o n : Pulre-Jet P i l o t

Unit Experience.' tPA-600/7-82-062 (NTIS PB 83-168 625). November

1982.

VanOidell, D.W., and Furlong, D.A. 'E lec t ror ta t ic Augrcntation of

Fabric F i l t r a t i o n : Pcverre-fir P i l o t Unit Experience.' EPA-600/

7-84085 (i?TIS PB 84-230 002). bgU8t 1986.

3. Furlong, D.A., Crelner , C.P., VanOrdell, D.W., and b v i r , L.S.

'X lec t ro i ta t ic Stimulation of Reverse-Air-Cleaaed ?abrlc ?ilter8.'

In:

Control Technology, Volume I, I a b r i c ? i l t r a t i o n , tPA-600/9-84-O2k

(B'XIS PB85161 8911, pp. 287-302, lbvember 1984.

Fourth symporium on the T r m r f e r and U t i l i r a t l o n of P a r t i c u l a t e

.

4. ?bntlur, D.E., &8h, P.V., and spark8, L.E. -A &w ?recharger f o r

* S t y e t h C t r O 8 t a t l C Prcc ip i t8 t lon of Bigh k r i r t i r i t y Rut.'

spp08itm on t he T r u u f e r and U t i l f t a t i o n of Pa r t i cu la t e Control

fo:

1

14 N. Plaks

Technology, Vol. I. E lec t ros t a t i c Prec ip i ta tors , EPA-600/7-79-044a

(NTIS PB 295 226), pp. 275-285, February 1979.

5. Pinard, C., Rugg, D., 8nd hrh.m, n. “Evaluation of R e c h u g e r r f o r

Traarfer and Ut i l i za t ion of Pa r t i cu la t e Control Technology, Volume XI,

E l e c t r o r t a t i c ) reCipi ta t ion, LPA-600/9-84-OZSb (NTIS PB85-161 909) pp.

84-95, November 1984.

6. Sparks, L.E., Plake, I., 8nd Baasty, C.E.

Par t i cu la t e and SO2 Uoing E-SOX.”

Derulfurizatlon, Cincinnati , Ohio, June 4-7, 1985.

‘Investigation of Combined

Ninth Symporim on Flue Cas .

7. Martin, C.B., Abbott, J.E., a d Sparks, L.E. “Advances I n Control

Technology f o r Acid Deposition,” Second U.S.-Dutch Internat ional

Symposium: Aerosols, Williamsburg, Virginia, b y 19-24, 1985.

8. Faulkncr, M.G., and W a r d , J.L.

R e c i p i t a t l o n (Bevirion 3)”

“A Mathematical Uodel of E lec t ros t a t i c

Volo. I and XI, EPA-600/7-84-069a and b

(NTIS PB 84-212 679 and 84-212 687). June 1984.

table I. CQBARISON OF LARGE IWD SHALL DXAUEIER DfSCBllELCE ~CIIILODES

tlectric field ratio.. (EL& 1

W j s )

(pL/Ps)

( q / v s 1

Current denrity ratio

Power ratio

Overall migration velocity ratio

Penetration ratio (PtL/PtS 1

1.60 1.19

0.41 0.69

0.55 0.81

1.12 1.33

0.80 0.25

- NOTE: Subrcript L referr to large diameter electrode, and rubrcript S refers to small dimetcr electrode.

-

16 1. P l o k s

e r u n i c hubton -

Woldd Joint

I I I I. Plaks

.

J.?. $tnenr U 8 f8bWIas Fabric Without Electrodes

0.32 em 316 35 Braid

J.?. Stevens (i48 Woven €loctrode frbr ic

8.U m

I I

i O.tS m

L *e 2. Reverse-Air Woven-In Electrode ESrF h i t

L O

N. P l a k s

0

d 0

0 a L

k k v1 iL:

w C

C & 3 c cr 0 Y 0 Y b L w

n

CI

.I

Y b

E L

&b

I L Y 1. 'P l iks

To High Voltage

2 Conductive f ilterbag

L U

8 . P 1 . b

.-

Outlet - =4

I

Inwlat or

Filterbag

Cell Plate

Top vlew c

g

i

i c t

8 P

c

t

t

. 9

m L, 5 .D a

W FlRutc 7. Multista~c Electrostatic Preclpltotor

. I-

.

23 N. P 1 . b

‘1’

T

I, g I I = -

I: n

4 L,

0

8 8 r a 0