Directory UMM :Data Elmu:jurnal:E:Environmental Management and Health:Vol10.Issue2.1999:
Economic comparison of pulsed electrostatic
precipitators and fabric filters in coal-fired utility
plants
Antonio C. Caputo
De partme nt o f Ene rge tic s, Fac ulty o f Engine e ring, Unive rsity o f L’ Aquila,
Mo nte luc o , L’ Aquila, Italy
Pacifico M . Pelagagge
De partme nt o f Ene rge tic s, Fac ulty o f Engine e ring, Unive rsity o f L’ Aquila,
Mo nte luc o , L’ Aquila, Italy
Keywords
Analysis, Co al, Co ntro l,
Enviro nme nt, Fabric
Abstract
Ele c tro static pre c ipitato rs (ESP)
and fabric filte rs (FF) are the main
air po llutio n c o ntro l e quipme nt
utilize d to c le an dust lade n fume s
fro m utility bo ile rs. The c ho ic e
amo ng the se syste ms de pe nds o n
spe c ific site c o nditio ns suc h as
dust c harac te ristic s, re quire d
e ffic ie nc y, gas flo wrate and
te mpe rature . ESP are ge ne rally
c harac te rize d by highe r c apital
inve stme nts and lo we r o pe rating
c harge s, while the o ppo site may
be said fo r FF bagho use s. As a
c o nse que nc e , ESP pre se nt highe r
to tal c o sts whe n high spe c ific
c o lle c tio n are as are re quire d, as
happe ns in the c ase o f lo w-sulfur
high-re sistivity dust. Ho we ve r,
signific ant re duc tio ns in bo th
c apital inve stme nt and o pe rating
c harge s may be o btaine d with
pulse d e ne rgizatio n o f pre c ipitato rs wo rking in se ve re bac k
c o ro na c o nditio ns. This po ssibility
gre atly e nlarge s the fie ld o f
applic atio ns in whic h ESP are a
lo we r c o st o ptio n c o mpare d to
fabric filte rs. In the pape r an
e c o no mic c o mpariso n o f pulse
e ne rgize d ESP, with c o nve ntio nal
ESP, re ve rse -air, shake r, and
pulse -je t bagho use s is pe rfo rme d.
A mapping o f the o pe rating
c o nditio ns in whic h the ado ptio n
o f e ac h e xamine d c o ntro l te c hno lo gy is e c o no mic ally c o nve nie nt is
also de fine d.
Enviro nme ntal Manage me nt
and He alth
1 0 / 2 [ 1999] 9 6 –1 0 4
© MCB Unive rsity Pre ss
[ ISSN 0956-6163]
[ 96 ]
Introduction
Th e a doption of m or e a n d m or e str in gen t
pa r ticu la te em ission r e gu la tion s a n d th e
developm en t of im pr oved a ir -pollu tion con tr ol devices h ave r esu lted in th e in cr ea sed
a pplica tion of electr osta tic pr ecipita tor s
(E SP ) a n d fa br ic fi lter s (F F ). On e a r ea wh er e
both E SP a n d F F h ave a ch ieved m u ch w ider
u se is in th e con tr ol of pa r ticu la te em ission s
fr om in du str ia l a n d u tility coa l-fi r ed boiler s.
Th e m a jor pu r pose of th is stu dy is to iden tify
th e r a n ge of power pla n t oper a tin g con dition s
in wh ich E SP a n d F F fin d th eir optim a l u se
fr om a n econ om ic poin t of view. A su bsta n tia l
body of r esea r ch r esu lts h a s been pu blish ed
descr ibin g th e fa ctor s in fl u en cin g th e effectiven ess of E SP a n d F F, m u ch of wh ich h a s
been dir ected tow a r ds th e ch a r a cter iza tion of
coa l a sh pa r ticles a n d bu lk coa l a sh beh aviou r. For F F, th e coh esivity of th e a sh
deposited in th e du st ca k e is a k ey fa ctor
deter m in in g th e collection efficien cy a n d
filter clea n a bility (Bu sh et a l., 1986). Am on g
a sh es h avin g sim ila r pa r ticle size distr ibu tion , coh esivity is th e distin gu ish in g pa r ticu la te pr oper ty. Poor fi ltr a tion efficien cy h a s
been a ssocia ted w ith extr em ely low a sh coh esivity (Felix et a l., 1986). Coh esivity h a s been
cor r ela ted w ith coa l a n d a sh ch em istr y, fl u e
ga s tem per a tu r e a n d h u m idity, pa r ticle size
distr ibu tion a n d m or ph ology.
Th r ee ph en om en a in stea d a ffect th e over a ll
E SP per for m a n ce, n a m ely r e-en tr a in m en t in
th e ga s str ea m of collected pa r ticu la te du e to
r a ppin g of collectin g pla tes, ga s flow by-pa ssin g th e in ter -electr ode spa ce (sn ea k a ge) a n d
em ission of positive ion s by th e deposited
du st layer (ba ck cor on a ). However, a m a jor
fa ctor is th e a sh r esistivity wh ich in flu en ces
th e m igr a tion velocity. Ash r esistivity h a s
been sh ow n to depen d on coa l ch em istr y, ion
m obility, flu e ga s tem per a tu r e a n d h u m idity,
a s well a s th e con cen tr a tion of H 2O, O 2 a n d
SO 3 in th e flu e ga s (Bick elh a u pt, 1975). High
r esistivity (a bove 1011oh m cm ) m ay ca u se th e
on set of th e ba ck cor on a effect, in tr odu cin g
positive ion s in to th e ga s spa ce, th u s r edu cin g
th e pa r ticles ch a r ge a n d th e collection a bility
of th e E SP. In or der to solve th e ba ck cor on a
pr oblem th e m ost pr om isin g solu tion is
offer ed by th e pu lse or in ter m itten t en er giza tion wh er eby sh or t h igh volta ge pu lses a r e
su per im posed r epetitively on a DC ba se volta ge (Ha ll, 1990; La u sen , 1990; N elson a n d
Sa la soo, 1987). In th is w ay sign ifica n t
im pr ovem en ts of pa r ticle ch a r gin g a n d cu r r en t den sity distr ibu tion m ay be obta in ed
com pa r ed to con ven tion a l en er giza tion . Th is
r esu lts in th e elim in a tion of th e ba ck cor on a
ph en om en on a n d in a r edu ction of both th e
r equ ir ed specific collection a r ea (SCA) a n d
power con su m ption . However, th e cost of a
pu lse en er giza tion system is a bou t fou r tim es
gr ea ter com pa r ed to a con ven tion a l on e for
su pply of a pr ecipita tor w ith th e sa m e collectin g a r ea (La u sen , 1990). In pr eviou s wor k s
com pa r ison s between pu lsed a n d con ven tion a l E SP h ave been ca r r ied ou t by th e
a u th or s in differ en t in du str ia l a pplica tion s
(Ca pu to a n d Pela ga gge, 1997; Pela ga gge et a l.,
1996).
With th e a im of ver ifyin g th e effective a pplica tion fea sibility of pu lsed E SP in power
pla n ts, a stu dy on econ om ic ch a r a cter istics of
pu lsed E SP in com pa r ison w ith con ven tion a l
E SP a n d differ en t k in ds of fa br ic filter s h a s
been u n der ta k en . In th e pa per a ch a r a cter iza tion of str ea m s to be tr ea ted in coa l-fir ed
u tility pla n ts h a s been pr elim in a r ily ca r r ied
ou t. In th is w ay sign ifica n t oper a tin g scen a r ios h ave been defin ed in ter m s of du st r esistivity, collection efficien cy a n d pollu ted
str ea m flow r a te. Un der su ch h ypoth eses, a
com pa r a tive sizin g of pu lse en er gized a n d
con ven tion a l pla te-w ir e E SP, a n d sever a l
types of fa br ic filter s (sh a k er, r ever se-a ir, a n d
pu lse-jet clea n in g) h a s been th en per for m ed.
Th e sizin g of con ven tion a l E SP h a s been
ca r r ied ou t a ccor din g to a m odified liter a tu r e
m odel (Tu r n er et a l., 1988). Th e per for m a n ce
of th e pu lsed system h a s been in stea d eva lu a ted r esor tin g to ava ila ble liter a tu r e exper im en ta l da ta th a t fu r n ish th e va lu e of th e
Antonio C. Caputo and
Pac ific o M. Pelagagge
Ec o no mic c o mpariso n o f
pulse d e le c tro static
pre c ipitato rs and fabric filte rs
in c o al-fire d utility plants
Enviro nme ntal Manage me nt
and He alth
1 0 / 2 [1 9 9 9 ] 9 6 –1 0 4
efficien cy en h a n cem en t fa ctor (defin ed a s th e
r a tio between pu lsed a n d con ven tion a l effective m igr a tion velocity) a s a fu n ction of du st
r esistivity (Pela ga gge et a l., 1996). Sizin g of
fa br ic filter s h a s been per for m ed on th e ba sis
of liter a tu r e da ta a n d sta n da r d pr ocedu r es
(Tu r n er et a l., 1987). Cr iter ia for estim a tin g
ca pita l a n d a n n u a l cost fa ctor s h ave been
over viewed in th e pa per a ccor din g to sta n da r d pr a ctice (E PA, 1987; Va tavu k , 1990).
F in a lly, th e im pa ct of pu lse en er giza tion in
coa l-fir ed u tility pla n ts h a s been eva lu a ted
a n d th e oper a tin g con dition s in wh ich th e
a doption of ea ch exa m in ed con tr ol tech n ology is econ om ica lly con ven ien t h ave been
defin ed.
Operating scenario definition
Th e w idely va r ia ble coa l ch a r a cter istics in
ter m s of h ea tin g va lu e, su lfu r a n d a lk a li con ten t, com position , a sh con ten t, a n d r equ ir ed
com bu stion a ir, m a k e difficu lt a n y dir ect
com pa r ison between E SP a n d F F. In or der to
over com e th is pr oblem , th e str ea m to be
clea n ed h a s been ch a r a cter ized on ly r efer r in g to du st r esistivity a n d ga s flow r a te, in depen den tly fr om coa l type a n d boiler ca pa city.
Du st loa din g a n d size distr ibu tion h ave been
in stea d a ssu m ed w ith r efer en ce to pu lver ized
coa l boiler s. In pa r ticu la r, a n aver a ge m a ss
m ea n dia m eter of 15 µm h a s been h ypoth esized a t th e clea n in g device in let. Usu a l du st
loa din g for pu lver ized coa l boiler s r a n ges
between 2 a n d 7g/ m 3. Va lu es of 3 a n d 6g/ m 3
h ave been h er e a ssu m ed lea din g to a r equ ir ed
design collection efficien cy of 0.99 a n d 0.995
in or der to com ply w ith th e N SP S (N ew
Sou r ce Per for m a n ce Sta n da r d) lim its of
a bou t 30m g/ m 3. F lu e ga s tem per a tu r e h a s
been set a t 140°C.
Du st r esistivity in a ctu a l oper a tin g con dition s ca n be estim a ted by r esor tin g to liter a tu r e da ta or com pu ted a s a fu n ction of a sh
a n d fu m es com position , m oistu r e a n d tem per a tu r e. In th is wor k th r ee differ en t du st
r esistivity va lu es h ave been con sider ed: low
r esistivity (ρ = 1· 109oh m cm ), m ediu m (ρ =
1· 1011oh m cm ) a n d h igh r esistivity
(1· 1012oh m cm ) cor r espon din g to th e ca ses of
h igh , m ediu m a n d low su lfu r con ten t. F in a lly,
flow r a te va lu es fr om 50 u p to 800m 3/ s h ave
been con sider ed cor r espon din g to a boiler
size r a n gin g fr om 30 to 450MW.
ESP cost evaluation
E SP ca pita l a n d oper a tin g costs ca n be
dir ectly cor r ela ted to th e collectin g a r ea . A
fir st sim plified sizin g a ppr oa ch r elies on
estim a tion of th e effective pa r ticle m igr a tion
velocity fr om exper im en ts in pilot u n its or
fr om exper ien ce w ith sim ila r pla n ts. In th is
ca se th e r equ ir ed pla te a r ea ca n be obviou sly
obta in ed fr om th e cla ssic Deu tsch efficien cy
equ a tion a s m odified by Ma tts a n d Oh n feldt
(1973)
η =1− e
( − w SC A )k
(1)
wh er e w is th e effective m igr a tion velocity
(wh ich r a n ges fr om 2 to 40cm / s a ccor din g to
pr ecipita tor con figu r a tion , coa l type a n d ba ck
cor on a sever ity), η is th e collection efficien cy,
SCA is th e r a tio of collectin g a r ea (A) to
a ctu a l ga s flow r a te (Q), k is a coefficien t
m ea su r in g th e polydisper sion of pa r ticle size
distr ibu tion (u su a lly k = 0.5 a n d in cr ea ses u p
to 1 for m on odisper se pa r ticles).
In th is wor k th e sizin g pr ocedu r e pr oposed
by Tu r n er et a l. (1988) h a s been in stea d
a dopted to ta k e in to a ccou n t w ith gr ea ter
deta il losses der ivin g fr om flow sn ea k a ge a n d
r a ppin g r een tr a in m en t of collected pa r ticu la te. Ba ck cor on a effect h a s been con sider ed
by r edu cin g u p to a fa ctor 0.6 th e aver a ge
electr ic field ava ila ble for pa r ticle ch a r gin g
a n d m igr a tion . On ce deter m in ed th e r equ ir ed
pla te a r ea for a pr ecipita tor w ith con ven tion a l en er giza tion , th e a r ea of th e cor r espon din g pu lse en er gized pr ecipita tor is
sim ply defi n ed a s A p = A c / H (wh er e p sta n ds
for pu lsed a n d c for con ven tion a l). An efficien cy en h a n cem en t fa ctor H = w p / w c h a s
been a dopted to a ccou n t for th e in cr ea se in
effective pa r ticle m igr a tion velocity exper ien ced w ith pu lse en er giza tion . Cor r ela tion s
w ith du st r esistivity or w ith pr ecipita tor
pen etr a tion (Pela ga gge et a l., 1996; E P RI, 1986)
obta in ed by r esor tin g to ava ila ble liter a tu r e
exper im en ta l da ta ca n be em ployed to estim a te aver a ge va lu es of H. Her e th e follow in g
cor r ela tion h a s been a dopted (Pela ga gge et
a l., 1996):
ρ < 1 ⋅ 1011, H = 1
11
13
1 ⋅ 10 < ρ < 2 ⋅ 10 , H = ( 0.13881n ρ ) − 2.3468
(2)
ρ > 2 ⋅ 1013 , H = 2
However, it sh ou ld be n oted th a t con sider a ble
disper sion exists in exper im en ta l da ta a n d H
va lu es sh ow depa r tu r es u p to ± 50 per cen t
fr om th e aver a ge va lu es. Th e E SP fl a n ge to
fla n ge ba se cost ($) in clu din g sta n da r d
option s a n d in su la tion , a s a fu n ction of th e
collectin g a r ea is (Tu r n er et a l., 1988):
C = 5170.51 A 0.6276
C = 812.47A 0.8431
for A < 4600m 2
(3)
for A > 4600m 2 .
(4)
Th e cost of th e power su pply is
C P Sc = 0.12C
(5)
[ 97 ]
Antonio C. Caputo and
Pac ific o M. Pelagagge
Ec o no mic c o mpariso n o f
pulse d e le c tro static
pre c ipitato rs and fabric filte rs
in c o al-fire d utility plants
Enviro nme ntal Manage me nt
and He alth
1 0 / 2 [1 9 9 9 ] 9 6 –1 0 4
CP Sp = 0.45C.
(6)
Oth er costs (a u xilia r ies, in sta lla tion , in dir ect) m ay be a ssu m ed a s
C A = 1.53C
(7)
lea din g to th e follow in g tota l ca pita l in vestm en t (TCI)
TCI c = 2.65C
(8)
TCI p = 2.98C.
(9)
Dir ect a n n u a l costs ta k e a ccou n t of oper a tin g
la bor (OL), su per visin g la bor (SL), m a in ten a n ce la bor (ML), m a in ten a n ce m a ter ia ls
(MM) a n d en er gy cost (E ). Oper a tin g la bor
r equ ir em en t h a s been com pu ted a s 1 h r / sh ift
w ith a n h ou r ly r a te of $15/ h r, su per visin g
la bor h a s been con sider ed a s 15 per cen t of OL,
m a in ten a n ce m a ter ia ls cost h a s been ta k en a s
1 per cen t of equ ipm en t ba se cost C. Ma in ten a n ce la bor h a s been com pu ted a s 0.15
h r / week per ea ch 100m 2 of collectin g a r ea if A
> 4,650m 2, a n d 8h r / week wh en A < 4,650m 2.
Hou r ly m a in ten a n ce la bor r a te h a s been
a ssu m ed a s $18. E n er gy cost ($/ yr ) for fa n
oper a tion is
E F = 1.53( ∆p Q ) TYC E
(10)
wh er e ∆p is th e pr essu r e dr op a cr oss th e
equ ipm en t, Q (m 3/ s) is th e ga s flow r a te, T Y is
th e a n n u a l oper a tin g tim e (h r / yr ) a n d CE is
electr icity cost. It h a s been a ssu m ed ∆p = 250
P a , T Y = 8,640 h r / yr, C E = $0.06/ k Wh . F a ctor
1.53 a ccou n ts for a 65 per cen t fa n efficien cy.
E n er gy r equ ir ed for both cor on a disch a r ge,
in clu din g losses in T/ R sets, a n d r a pper s
oper a tion h a s been com pu ted by a ssu m in g a
specific power den sity P (con sider ed con sta n t
in th e exa m in ed efficien cy r a n ge) wh ich
differ s for con ven tion a l (P c = 20W/ m 2) a n d
pu lsed (P p = 12W/ m 2) E SP :
E D = P A TY CE .
(11)
As a r esu lt, th e dir ect a n n u a l costs a r e
DAC = OL + SL + ML + MM + E F + E D.
(12)
In dir ect a n n u a l costs (IDC) a r e expr essed a s
IDC = 0.6 (OL + SL + ML + MM) + 0.04 TCI. (13)
Ba sed on th e tota l ca pita l in vestm en t TCI a n d
th e oper a tin g a n n u a l costs AC = DAC + IDC,
th e tota l a n n u a l cost TAC h a s been eva lu a ted
su m m in g to th e oper a tin g costs th e ca pita l
r ecover y costs
TAC = AC + (TCI CRF )
(14)
wh er e th e ca pita l r ecover y fa ctor is
CRF =
[ 98 ]
i (1 + i ) N
(1 + i ) N − 1
(15)
w ith i th e a n n u a l in ter est r a te (i = 10 per cen t)
a n d N th e pla n t life (N = 20 yea r s). Costs of
a sh h a n dlin g equ ipm en t a n d disposa l, a s well
a s du ctwor k s a n d m a in fa n s h ave been
n e glected bein g com m on to both E SP a n d F F.
All equ ipm en t costs, ba sed on liter a tu r e cor r ela tion s, h ave been esca la ted to cu r r en t
va lu es r esor tin g, wh er e a pplica ble, to th e
P r odu cer P r ice In dex (P P I), th e Ma r sh a ll a n d
Sw ift cost in dex or th e Va tavu k Air Pollu tion
Con tr ol Cost In dexes (VAP CCI) pu blish ed
m on th ly in Ch em ica l En gin eer in g jou r n a l.
Fabric filter cost evaluation
Sever a l k in ds of clea n in g m eth ods h ave been
con sider ed, n a m ely r ever se-ga s (RGF F ),
sh a k er (SF F ) a n d pu lse-jet (P J F F ) fa br ic filter s. RGF F a n d SF F a r e ba sica lly sim ila r
except th a t RGF F a r e clea n ed in a gen tler w ay
th r ou gh a r ever se a ir flow wh ile SF F a r e
m ech a n ica ly sh a k en to obta in deposited du st
dislodgem en t. Th is en a bles a better clea n in g
of SF F ba gs r esu ltin g in a h igh er a llow a ble
per m ea tion velocity a t a given pr essu r e dr op
(h en ce a sm a ller filter in g a r ea ), bu t m ay
ca u se a sh or ter ba g life. P J F F in stea d a r e
clea n ed on -lin e w ith com pr essed a ir jets a n d
en a ble n ea r ly dou bled per m ea tion velocity
dr a stica lly cu ttin g th e r equ ir ed ba g a r ea .
However, on ly in r ecen t yea r s h ave P J F F been
w idely a ccepted in th e u tility in du str y (Belba
et a l., 1992; Dea n a n d Cu sh in g, 1988), a n d
cu r r en tly th e m a jor ity of ba gh ou ses in boiler
in sta lla tion s a r e still of th e RG k in d. A
deta iled a n a lysis of fa br ic filter s design a n d
oper a tion a l issu es m ay be fou n d in E P RI (1992
a -b).
Also in th e ca se of F F, costs a r e cor r ela ted
to filtr a tion a r ea (Tu r n er et a l., 1987). Th e
filter gr oss a r ea A (m 2) is com pu ted on th e
ba sis of th e r equ ir ed n et a r ea , dicta ted by th e
flow r a te a n d th e a llow a ble per m ea tion velocity (u su a lly descr ibed a s “a ir -cloth r a tio”,
ACR), su ita bly in cr ea sed th r ou gh a fa ctor F
a ccou n tin g for th e r equ ir ed extr a ba gs to be
in sta lled in or der to a llow off-lin e ba g
clea n in g:
Q
A=
F.
ACR
(16)
To eva lu a te fa ctor F th e follow in g cor r ela tion
h a s been u sed (a da pted fr om Tu r n er et a l.,
1987):
A < 16, 700m 2 , F = 2.06( A −0.0715 )
2
(17)
A > 16, 700m , F = 1.04.
In th e ca se of P J F F it is a lw ays F = 1. Ba sed on
typica l va lu es a dopted in th e u tility in du str y
for coa l fi r ed boiler s, th e selected ACR va lu es
Antonio C. Caputo and
Pac ific o M. Pelagagge
Ec o no mic c o mpariso n o f
pulse d e le c tro static
pre c ipitato rs and fabric filte rs
in c o al-fire d utility plants
Enviro nme ntal Manage me nt
and He alth
1 0 / 2 [1 9 9 9 ] 9 6 –1 0 4
for P J F F, RGF F, a n d SF F a r e 0.02, 0.01, 0.015
m / s r espectively (Belba et a l., 1992; E P RI, 1992
a -b; Sloa t et a l., 1993).
Th e com pu ted gr oss a r ea cor r espon ds to a
n u m ber of ba gs N B wh ich obviou sly depen ds
on ba g su r fa ce B S (N B = A / B S ). In th is wor k
th e follow in g u su a l ba g sizes h ave been con sider ed: 6.1 m lon g w ith 150m m dia m eter for
P J F F (B S = 2.87m 2), 9.75 m lon g w ith 300m m
dia m eter for both RGF F a n d SF F (BS =
9.19m 2) (Belba et a l., 1992; E P RI, 1992a b; Sloa t
et a l., 1993).
P u r ch a sed equ ipm en t cost (P E C) is gen er a lly com posed of th e ba gh ou se cost C B H , in su la tion cost C I , a n d tota l ba gs cost C BT . For
P J F F on ly, th e cost of th e ca ges su ppor tin g
th e ba gs C TC sh ou ld be a dded, wh ile for RGF F
th e cost of th e r ever se a ir fa n C RAF is to be
in clu ded. Ava ila ble cor r ela tion s for ba gh ou se
a n d in su la tion costs ($) a r e (Tu r n er et a l.,
1987):
m a ter ia l cost is a ssu m ed equ a l to ML cost. A
m a jor dir ect oper a tin g cost is ba g r epla cem en t con sider ed a s th e su m of a ctu a l ba g
cost, com pr isin g fr eigh t, a n d r epla cem en t
la bor. As ba gs a r e ch a n ged a t th e en d of th eir
u sefu l life B L , ba g r epla cem en t cost is essen tia lly a r epea ted in vestm en t th a t ca n be con sider ed a s u n ifor m ly distr ibu ted over th e
pla n t life by in tr odu cin g a pr oper ba g ca pita l
r ecover y fa ctor CRF B com pu ted over ba g life.
Ba g life a ssu m ed for P J F F, RGF F, SF F is 2.5,
fou r a n d th r ee yea r s r espectively (Belba et a l.,
1992; E P RI, 1992 a -b; Sloa t et a l., 1993). As a
con sequ en ce, th e equ iva len t a n n u a l ba g
r epla cem en t cost is expr essed a s
C ABR = CRFB CBR
(29)
for RGF F (930m 2< A < 7,430m 2)
C BH = 39479 + ( A 101.777)
is th e a ctu a l ba g r epla cem en t cost, w ith M LR
th e m a in ten a n ce la bor r a te ($/ h r ), B RT th e
ba g r epla cem en t tim e (7.5 m in u tes for P J F F
a n d 15 for oth er types).
E n er gy cost for fa n oper a tion ($/ yr ) ca n be
com pu ted a ccor din g to equ a tion 10. However,
pr essu r e dr op is th e su m of ba gh ou se pr essu r e dr op (a ssu m ed 400P a ) a n d “tu besh eet”
pr essu r e dr op a cr oss ba gs a n d du st ca k e. Th is
h a s been a ssu m ed a s 1,300, 1,500, 1,440P a for
P J F F, RGF F, a n d SF F r espectively (Belba et
a l., 1992; E P RI, 1992 a -b; Sloa t et a l., 1993). For
RGF F a lso th e en er gy for r ever se a ir fa n is to
be a ccou n ted for, con sider in g th a t it oper a tes
con tin u ou sly on a bou t 10 per cen t of th e gr oss
a r ea , w ith a n ACR typica lly 1.5 tim es th e
for w a r d ACR, a n d w ith a du st ca k e pr essu r e
loss of a r ou n d 1,620 P a . In ca se of SF F,
in stea d, en er gy cost E S ($/ yr ) for th e sh a k er
m ech a n ism is to be con sider ed, given by
E S = 0.5704 A ( T Y / 8760) CE .
(31)
C I = 1523 + ( A 11.6206)
for P J F F (370m 2< A < 1,300m 2)
C BH = 63727 + ( A 106.3683)
C I = 4045 + ( A 30.1661)
for SF F (370m 2< A < 5,570m 2)
C BH = 50567 + ( A 108.4668)
C I = ( A 4.8659)
(18)
(19)
(20)
(21)
(22)
(23)
a n d, for la r ge sized ba gh ou ses, in depen den tly
fr om clea n in g m eth od (9,290m 2< A < 37,160m 2)
C BH = 303404 + ( A 80.1369)
(24)
CI = 81150 + ( A 9.2466).
(25)
Tota l ba gs cost is C BT = C B A wh er e C B is th e
specific ba g cost ($/ m 2). C B va lu es of 32 a n d
$8.7/ m 2 h ave been a ssu m ed for P J F F, a n d
eith er RGB or SF F (Va tavu k , 1990; Sloa t,
1993). Sta in less steel ca ge cost C C ($) is cor r ela ted to ba g su r fa ce w ith :
CC = 12.201 + ( B S 2.267).
(26)
Tota l ca ges cost ($) is C TC = N B C C . Rever se a ir
fa n cost ($) is C RAF = 411.38 Q.
P u r ch a sed equ ipm en t cost, in clu din g
in str u m en ta tion , ta xes, a n d fr eigh t, is:
P E C = 1.18 (CBH + CI + CBT + CRAF + CTC )
(27)
wh ich , con sider in g in sta lla tion costs, lea ds to
a TCI given by
(28)
TCI = 2.17 P E C.
For wh a t con cer n s OL costs a r equ ir em en t of
2 h r / sh ift is con sider ed, wh ile ML is com pu ted a ssu m in g 1h r / sh ift. SL cost is com pu ted a s seen for E SP wh ile m a in ten a n ce
wh er e
CBR = [ ( M LR 1.6 N B ( B RT / 60) + (1.08 A CB )]
(30)
F in a lly, a llow a n ce sh ou ld be m a de for P J F F
com pr essed a ir r equ ir em en t th a t ca n be com pu ted on th e ba sis of 0.002m 3/ s (STP ) of com pr essed a ir per u n it ga s flow r a te a t a cost of
$25.4/ h r per u n it com pr essed a ir flow r a te
(STP ).
In dir ect a n n u a l costs a r e com pu ted a s
descr ibed for E SP. Tota l a n n u a l costs a r e
com pu ted exclu din g CBR fr om th e ca pita l
r ecover y a s ba g cost is a lr ea dy com pu ted in
oper a tin g costs:
(32)
TAC = AC + [ (TCI -CBR ) CRF ].
Economic analysis
A pa r a m etr ic a n a lysis ba sed on ga s flow r a te,
pr ecipita tor efficien cy a n d du st r esistivity
h a s been per for m ed eva lu a tin g th e
[ 99 ]
Antonio C. Caputo and
Pac ific o M. Pelagagge
Ec o no mic c o mpariso n o f
pulse d e le c tro static
pre c ipitato rs and fabric filte rs
in c o al-fire d utility plants
Enviro nme ntal Manage me nt
and He alth
1 0 / 2 [1 9 9 9 ] 9 6 –1 0 4
cor r espon din g tota l ca pita l in vestm en t (TCI),
a n n u a l oper a tin g costs (AC), a n d tota l a n n u a l
costs (TAC) for th e five a ir pollu tion con tr ol
devices con sider ed. In ca se of F F, n o a ttem pt
to eva lu a te costs ou tside th e decla r ed va lidity
r a n ge of ava ila ble cor r ela tion s h a s been
m a de. Th er efor e, n ot a ll k in ds of F F h ave
been sized a n d costed over th e en tir e fl ow r a te
r a n ge. However, for la r ge fl ow r a tes, i.e. la r ge
ba gh ou ses, th e flow r a te h a s been split
between two pa r a llel u n its th a t h ave been
sin gu la r ly costed, givin g r ise to th e discon tin u ities a ppea r in g in th e figu r es.
F igu r e 1 depicts th e TCI a ccor din g to th e
two con sider ed efficien cy va lu es. In th e ca se
of low r esistivity coa l (F igu r e 1a ), wh er e n o
ben efit in effective m igr a tion velocity ca n be
expected fr om pu lsed en er giza tion , th e collectin g pla te a r ea is th e sa m e (SCA = 45.2 a n d
56.2s/ m depen din g on efficien cy) a n d pu lsed
E SP r esu lts m or e expen sive du e to th e h igh er
cost of th e power su pply u n its. P J F F a n d SF F
Figure 1
To tal c apital inve stme nt: (a) lo w, (b) high
re sistivity
[ 100 ]
sh ow r ou gh ly th e sa m e cost, wh ich is less
th a n RGF F ca pita l in vestm en t du e to th e
lower r equ ir ed ba g a r ea th a n k s to th e h igh er
a llow a ble ACR. In pa r ticu la r, th e effects of
size r edu ction is eviden t for P J F F wh ich a r e
ch a r a cter ized by th e lowest ca pita l cost even
if th e specific ba g cost is h igh er, wh ile RGF F
sh ow th e h igh est ca pita l cost. In th e ca se of
m ediu m r esistivity du st th e lower SCA of
pu lsed E SP (SCA c = 50.4s/ m , SCA p = 43s/ m a t
low efficien cy, wh ile SCA c = 62.6s/ m , SCA p =
53.4s/ m a t h igh efficien cy) is offset by th e cost
of th e en er giza tion equ ipm en t r esu ltin g in
n ea r ly equ iva len t TCI of both pr ecipita tor
types. Ben efits a r isin g fr om pu lsed en er giza tion fu lly sh ow in stea d in ca se of h igh r esistivity du st wh er e th e r edu ced pla te a r ea (F igu r e 1b: SCA c = 75.6 s/ m , SCA p = 50.7 s/ m
wh en efficien cy is 0.99 or SCA c = 93.9 s/ m ,
SCA p = 63 s/ m wh en efficien cy is 0.995) fu lly
offsets th e in cr ea sed cost of power su pply a n d
th e opposite situ a tion w ith r espect to F igu r e
1a is obser ved wh en com pa r in g E SP costs,
r esu ltin g in th e con ven tion a l E SP becom in g
th e h igh est in vestm en t option , wh ile th e
pu lsed E SP r em a in s com petitive w ith th e
RGF F. However, a s fa r a s ca pita l costs a r e
con cer n ed, P J F F a n d SF F r esu lt a lw ays th e
lowest cost option u n less a lower E SP efficien cy is specified.
Wh en oper a tin g costs a r e con sider ed (F igu r es 2a a n d b, r efer r in g r espectively to low
a n d h igh du st r esistivity) pu lsed E SP costs
a r e a lw ays lower th a n con ven tion a l E SP du e
to th e lower specifi c cor on a power, even in
ca se of low r esistivity coa l. Th e cost savin g
in cr ea ses a s du st r esistivity r ises du e to th e
a dded ben efit of a r edu ced pla te a r ea (F igu r e
2b). Mor eover, E SP a n n u a l costs a r e lower
th a n cor r espon din g costs of F F wh ich a r e
pen a lized by th e per iodica l ba g r epla cem en t.
On ly in ca se of ver y h igh r esistivity coa l
(F igu r e 2b) a n d h igh efficien cy th e r esu ltin g
collectin g a r ea of con ven tion a l E SP m ay lea d
to costs gr ea ter th a n th a t sh ow n by fa br ic
filter s (SF F ). P J F F a n d RGF F exper ien ce th e
h igh est oper a tin g costs a m on g F F, in th e fir st
ca se du e to th e sh or ter ba g life a n d th e m u ch
h igh er specific ba g cost, a n d in th e la tter ca se
ow in g to th e m u ch h igh er filter in g su r fa ce,
wh ile SF F sh ow lower cost in r espect to RGF F
du e to th e lower r equ ir ed a r ea (h igh er a llow a ble ACR) even if ba g life is sh or ter.
F in a lly, th e tota l a n n u a l cost, in clu din g
ca pita l r ecover y, is a n a lyzed in F igu r es 3 a n d
4. Th is is th e m a in econ om ic pa r a m eter th a t
m ay h elp in th e ch oice of th e lowest cost pollu tion con tr ol option . F igu r e 3 depicts TAC in
th e ca se of low E SP efficien cy (99 per cen t)
wh ile F igu r e 4 r efer s to h igh collection efficien cy (99.5 per cen t). In th is ca se th e cou n ter a ctin g effects of lower ca pita l costs a n d
Antonio C. Caputo and
Pac ific o M. Pelagagge
Ec o no mic c o mpariso n o f
pulse d e le c tro static
pre c ipitato rs and fabric filte rs
in c o al-fire d utility plants
Figure 2
Annual o pe rating c o sts: (a) lo w, (b) high
re sistivity c o al
Figure 3
To tal annual c o sts: ESP e ffic ie nc y (0 .9 9 ); (a)
lo w, (b) me dium, (c ) high re sistivity c o al
h igh er oper a tin g ch a r ges for F F a r e
eviden ced, wh ile th e opposite ca n be sa id for
E SP. P J F F a n d SF F sh ow sim ila r costs,
m a r k edly less th a n RGF F du e to th e lower
r equ ir ed ba g a r ea th a n k s to th e h igh er a llow a ble ACR. Th is expla in s th e su ccess r ecen tly
en cou n ter ed by P J F F in u tility a pplica tion s
n ow th a t th is tech n ology is fu lly m a tu r e. In
pa r ticu la r P J F F TAC is sligh tly la r ger th a n
SF F, in spite of th e su per ior size r edu ction
effect, du e to a h igh er oper a tin g cost ca u sed
by th e sh or ter ba g life a n d th e m u ch h igh er
specific ba g cost.
As fa r a s E SP a r e con cer n ed a distin ction
h a s to be m a de between low a n d m ediu m to
h igh du st r esistivity. In fa ct, a s a con sequ en ce
of th e obser ved tr en ds in E SP ca pita l a n d
oper a tin g costs, th e pu lsed type is a lw ays
con ven ien t in r espect of con ven tion a l E SP in
ca se of m ediu m to h igh r esistivity, bu t n ot in
ca se of low r esistivity (F igu r es 3a , 4a ). With
low r esistivity coa l pu lsed or con ven tion a l
E SP a r e a lower cost option com pa r ed to F F
(F igu r es 3a , 4a ) bu t th is com petitive m a r gin
r edu ces a s th e r equ ir ed efficien cy in cr ea ses.
In m ediu m r esistivity coa l a pplica tion s con ven tion a l E SP a r e still a com petitive option ,
w ith pu lsed E SP bein g in stea d a lower cost
option in com pa r ison w ith F F. In th e ca se of
h igh r esistivity in stea d (F igu r es 3c, 4c)
con ven tion a l E SP a r e a lw ays m or e costly
Enviro nme ntal Manage me nt
and He alth
1 0 / 2 [1 9 9 9 ] 9 6 –1 0 4
[ 101 ]
Antonio C. Caputo and
Pac ific o M. Pelagagge
Ec o no mic c o mpariso n o f
pulse d e le c tro static
pre c ipitato rs and fabric filte rs
in c o al-fire d utility plants
Figure 4
To tal annual c o sts: ESP e ffic ie nc y (0 .9 9 5 ); (a)
lo w, (b) me dium, (c ) high re sistivity c o al
Enviro nme ntal Manage me nt
and He alth
1 0 / 2 [1 9 9 9 ] 9 6 –1 0 4
th a n fa br ic fi lter s (especia lly P J F F a n d SF F ),
w ith pu lsed E SP bein g less costly a t low efficien cy a n d com petitive a t h igh efficien cy. In
con clu sion , a t low to m ediu m r esistivity both
k in ds of E SP a r e com petitive or con ven ien t
in r espect to F F, wh ile a t h igh r esistivity
on ly pu lsed E SP is eith er com petitive or
[ 102 ]
con ven ien t a ccor din g to th e flow r a te to be
tr ea ted a n d th e r equ ir ed efficien cy. RGF F ca n
be con sider ed com petitive w ith E SP on ly a t
h igh r esistivity a n d m ay r esu lt in bein g con ven ien t a t h igh efficien cy. In th e com pa r ison
of con ven tion a l E SP w ith RGF F a n d P J F F
su ch r esu lts a r e in a ccor da n ce w ith th ose of
ea r lier stu dies (E P RI, 1985, 1992c; Sloa t et a l.,
1993), even if th e n u m er ica l r esu lts a r e n ot
dir ectly com pa r a ble du e to differ en ces in th e
a ssu m ed econ om ic pr em ises; m or eover, som e
pieces of equ ipm en t a n d a n n u a l costs h ave
h er e been n e glected, bein g com m on to a ll
k in ds of devices.
In th e pr esen t a n a lysis th e cost eva lu a tion
h a s been per for m ed on th e ba sis of aver a ge or
typica l va lu es of th e oper a tin g pa r a m eter s.
However, pr esen t r esu lts a r e in dica tive a n d
va lid on ly u n der th e pr eviou sly sta ted
a ssu m ption s. In fa ct, site specifi c con dition s
m ay h eavily m odify th e econ om ic com pa r ison lea din g to va lu es of th e design pa r a m eter s su bsta n tia lly differ en t fr om th ose
a ssu m ed. As a n exa m ple, F igu r e 5 sh ow s th e
w ide TAC r a n ge th a t ca n ch a r a cter ize F F.
Upper a n d lower bou n ds of th e sh a ded a r ea
r epr esen t th e ca ses of pessim istic a n d optim istic design . For th e sa k e of sim plicity on ly
th e follow in g pa r a m eter s’ va r ia tion s h ave
been con sider ed (Belba et a l., 1992; Dea n a n d
Cu sh in g, 1988; E P RI, 1992b): tu besh eet pr essu r e dr op (P J F F : 480 to 2910P a ; RGF F : 890 to
1970P a ; SF F : 1060 to 1970P a ), a ir -cloth r a tio
(P J F F : 0.015 to 0.03m / s; RGF F : 0.007 to
0.011m / s; SF F : 0.012 to 0.016m / s), a n d ba g life
(P J F F : 1 to 5 yea r s; RGF F : 3 to 5 yea r s; SF F : 2
to 4 yea r s), wh ile th e possible va r ia tion of
fa br ic m a ter ia l a n d th e va r ia tion of its specific cost w ith ba gs dim en sion s a n d life h ave
been n e glected. Mor eover, in P J F F th e specific com pr essed a ir con su m ption h a s n ot
been cor r ela ted w ith aver a ge tu besh eet pr essu r e dr op n or h a s th e effect of clea n in g pu lse
pr essu r e been con sider ed.
F in a lly, th e pr oper ties of bu r n ed coa l h eavily in flu en ce th e ch oice of th e con tr ol device
for a given boiler size. As a n a pplica tion
exa m ple of th e m a ppin g r esu ltin g fr om th e
pr esen t stu dy, th e ca se of a 250MW boiler
fir in g th r ee differ en t coa ls is pr esen ted. Th e
ca lcu la ted va lu es of Ta ble I sh ow h ow th e
econ om ic ch oice is dicta ted by specific oper a tin g con dition s. Coa l a n d boiler ch a r a cter istics h ave been obta in ed by liter a tu r e da ta
(E P RI, 1985, 1992c). Th e cost va lu es m ay be
a lso eva lu a ted by dir ect in spection of figu r es
a n a logou s to th e pr eviou s on es, bu t com pu ted
for th e r equ ir ed E SP efficien cy a n d r esistivity, en ter in g w ith th e pr oper flow r a te. TAC
va lu es sh ow n in Ta ble I sh ow th a t for a low
r esistivity coa l lik e N or th Da kota lign ite, th e
con ven ien t ch oice is a con ven tion a l E SP even
Antonio C. Caputo and
Pac ific o M. Pelagagge
Ec o no mic c o mpariso n o f
pulse d e le c tro static
pre c ipitato rs and fabric filte rs
in c o al-fire d utility plants
in spite of th e h igh efficien cy r equ ir ed. For a
m ediu m r esistivity coa l in stea d (Appa la ch ia n
low su lfu r ) a pu lsed E SP (or a n SF F ) wou ld be
pr efer a ble even if a lower collection
efficien cy is r equ ested. F in a lly, in ca se of h igh
r esistivity du st (Wyom in g Pow der River
Ba sin coa l) th e lowest cost option wou ld be a n
SF F, w ith pu lsed E SP a n d P J F F sh ow in g
sim ila r bu t h igh er tota l costs.
Figure 5
Fabric filte rs to tal annual c o st range : (a)
re ve rse air, (b) shake r, (c ) pulse je t
Enviro nme ntal Manage me nt
and He alth
1 0 / 2 [1 9 9 9 ] 9 6 –1 0 4
Conclusions
In th is pa per a n econ om ica l com pa r ison
between pu lsed E SP a n d con ven tion a l E SP,
r ever se a ir, sh a k er, a n d pu lse-jet fa br ic filter s
h a s been ca r r ied ou t in th e coa l-fir ed boiler
a r ea . In th e ca se of low r esistivity du st, cor r espon din g to h igh su lfu r coa ls, con ven tion a l
E SP r esu lts econ om ica lly con ven ien t w ith
r espect to F F especia lly wh en th e ga s flow
r a te in cr ea ses. Th is is fu r th er con fir m ed
con sider in g r edu ced du st loa din g of th e
str ea m , givin g r ise to lower design collection
efficien cy. For m ediu m r esistivity coa l, econ om ic con ven ien ce of pu lsed E SP h a s been
poin ted ou t. Also in th is con dition , con ven ien ce of pu lsed E SP im pr oves wh en du st
loa din g decr ea ses a n d ga s flow r a te gr ow s.
Wh en low su lfu r coa ls a r e bu r n ed th e r esu ltin g h igh r esistivity du st defin itively pen a lizes th e con ven tion a l E SP. F F sh ow gen er a lly
better econ om ic r esu lts, w ith th e exception of
RGF F, even wh en com pa r ed to pu lsed E SP a t
lea st a s lon g a s h igh efficien cy is r equ ested
a n d F F per for m a ccor din g to design specifi ca tion s. F r om th is poin t of view fu r th er
r esea r ch effor ts h ave to be a im ed a t th e a n a lysis of coa l coh esivity effects on F F per for m a n ces a n d costs.
References
Belba , V.H., Gr u bb, V.T. a n d Ch a n g, R.L. (1992),
“Th e poten tia l of pu lse-jet ba gh ou ses for
u tility boiler s. P a r t 1”, J ou r n a l of th e A ir
Wa ste M a n a gem en t A ssocia tion , Vol. 42 N o. 2,
pp. 209-217.
Bick elh a u pt, R.E . (1975), “E ffect of ch em ica l com position on su r fa ce r esistivity of fl y a sh ”, E PA
r epor t 600/ 2-75-017.
Table I
Influe nc e o f c o al c harac te ristic s
Coal type
North Dakota
lignite
Appalachian
low sulfur
Wyoming
Powder River
Dust load Flow rate
ESP
Resistivity SCA(c) SCA(p)
Total annual cost ($M / year)
(g/ m3 )
(m3 / s) efficiency (ohm cm) (s/ m) (s/ m) ESP(c) ESP(p) PJFF RGFF
SFF
6.13
537.5
0.9951
1 × 10 9
56.5
56.5
2.63
2.77
2.98
3.40
2.77
3.98
412.9
0.9924
1 × 10 11
61.4
52.4
2.24
2.07
2.33
3.10
2.09
4.97
484.0
0.9939
1 × 10 12
89.4
59.9
3.52
2.66
2.70
3.55
2.40
[ 103 ]
Antonio C. Caputo and
Pac ific o M. Pelagagge
Ec o no mic c o mpariso n o f
pulse d e le c tro static
pre c ipitato rs and fabric filte rs
in c o al-fire d utility plants
Enviro nme ntal Manage me nt
and He alth
1 0 / 2 [1 9 9 9 ] 9 6 –1 0 4
[ 104 ]
Bu sh , P.V., Sn yder, T.R. a n d Ch a n g, R.L. (1986),
J ou r n a l of th e A ir Pollu tion Con trol A ssocia tion , Vol. 39 N o. 228.
Ca pu to, A.C. a n d Pela ga gge, P.M. (1997),
“E con om ic a n a lysis of pu lsed vs con ven tion a l
E SP s in in du str ia l a pplica tion s”,
En viron m en ta l M a n a gem en t a n d Hea lth , Vol.
8 N o. 3, pp. 100-4.
Dea n , A.H. a n d Cu sh in g, K.M. (1988), “Su r vey on
th e u se of pu lse-jet fa br ic fi lter s for coa l-fi r ed
u tility a n d in du str ia l boiler s”, J ou r n a l of th e
A ir Pollu tion Con trol A ssocia tion , Vol. 38 N o.
1, pp. 90-6.
E lectr ic Power Resea r ch In stitu te (1986), A n In v estiga tion of Precipita tor Pu lse En ergiz a tion ,
E P RI CS-4717.
E n vir on m en ta l P r otection Agen cy (1987), Econ om ic A n a lysis B ra n ch Con trol Cost M a n u a l,
E PA 450/ 5-87-001A (P B87-166583).
Felix, L.G., Mer r itt, R.L. a n d Du n ca n , W.S. (1986),
J ou r n a l of th e A ir Pollu tion Con trol A ssocia tion , Vol. 36, N o. 1075.
Ha ll, H.J . (1990), “Histor y of pu lse en er giza tion in
electr osta tic pr ecipita tion ”, J ou r n a l of
Electrosta tics, Vol. 25, pp. 1-22.
La u sen , P. (1990), “Applica tion of pu lse en er giza tion on elecr osta tic pr ecipita tor s for va r iou s
pr ocesses”, J ou r n a l of Electrosta tics, Vol. 25,
pp. 41-53.
Ma tts, S. a n d Oh n feldt, P.O. (1973), “E fficien t ga s
clea n in g w ith SF electr osta tic pr ecipita tor s”,
A B S v en sk a Fla k t T ech . B u ll.
N elson , J .K. a n d Sa la soo, L. (1987), “Th e im pa ct of
pu lse en er giza tion on electr osta tic pr ecipita tion per for m a n ce”, IEEE T r. on Electr ica l
In su la tion , Vol. E I-22 N o. 6, pp. 657-75.
Pela ga gge, P.M., Ca pu to, A.C. a n d Gia cch etta , G.
(1996), “E con om ic im pa ct of electr osta tic
pr ecipita tor s pu lse en er giza tion on dedu stin g
in ir on -or e sin ter in g pla n ts”, En viron m en ta l
M a n a gem en t a n d Hea lth , Vol. 7 N o. 5, pp. 21-6.
Tu r n er, J .H., Vin er, A.S., McKen n a , J .D., J en k in s,
R.E . a n d Va tavu k , W.M. (1987), “Sizin g a n d
costin g of fa br ic filter s”, J ou r n a l of th e A ir
Pollu tion Con trol A ssocia tion , Vol. 37, P a r t 1:
N o. 6, pp. 749-59; P a r t 2: N o. 9, pp. 1105-12.
Tu r n er, J .H., Law less, P.A., Ya m a m oto, T., Coy,
D.W., Gr ein er, G.P., McKen n a , J .D. a n d
Va tavu k , W.M. (1988), “Sizin g a n d costin g of
electr osta tic pr ecipita tor s”, J ou r n a l of th e A ir
Pollu tion Con trol A ssocia tion , Vol. 38, P a r t 1:
N o. 4, pp. 459-72; P a r t 2: N o. 5, pp. 715-26.
Va tavu k , W.M. (1990), Estim a tin g costs of A ir Pollu tion Con trol, Lew is P u blish er s, Ch elsea , MI.
Further reading
E lectr ic Power Resea r ch In stitu te (1985), Econ om ics of Fab r ic Filters a n d Electrosta tic Precipita tors – 1984, E P RI CS-4083.
E lectr ic Power Resea r ch In stitu te (1992a ), Fab r ic
Filters for th e Electr ic Utility In d u str y – Vol. 1:
Gen era l Con cepts, E P RI CS-5161.
E lectr ic Power Resea r ch In stitu te (1992b), Fab r ic
Filters for th e Electr ic Utility In d u str y – Vol. 5:
Gu id elin es for Fab r ic Filter Design , E P RI CS5161.
E lectr ic Power Resea r ch In stitu te (1992c), Econ om ic Eva lu a tion of Pa r ticu la te Con trol T ech n ologies: N ew Un its, E P RI TR-100748.
Sloa t, D.G., Ga ik w a d, R.P. a n d Ch a n g, R.L. (1993),
“Th e poten tia l of pu lse-jet ba gh ou ses for
u tility boiler s. P a r t 3: com pa r a tive econ om ics
of pu lse-jet ba gh ou se, pr ecipita tor s a n d
r ever se-ga s ba gh ou ses”, J ou r n a l of th e A ir
Wa ste M a n a gem en t A ssocia tion , Vol. 43 N o. 1,
pp. 120-8.
precipitators and fabric filters in coal-fired utility
plants
Antonio C. Caputo
De partme nt o f Ene rge tic s, Fac ulty o f Engine e ring, Unive rsity o f L’ Aquila,
Mo nte luc o , L’ Aquila, Italy
Pacifico M . Pelagagge
De partme nt o f Ene rge tic s, Fac ulty o f Engine e ring, Unive rsity o f L’ Aquila,
Mo nte luc o , L’ Aquila, Italy
Keywords
Analysis, Co al, Co ntro l,
Enviro nme nt, Fabric
Abstract
Ele c tro static pre c ipitato rs (ESP)
and fabric filte rs (FF) are the main
air po llutio n c o ntro l e quipme nt
utilize d to c le an dust lade n fume s
fro m utility bo ile rs. The c ho ic e
amo ng the se syste ms de pe nds o n
spe c ific site c o nditio ns suc h as
dust c harac te ristic s, re quire d
e ffic ie nc y, gas flo wrate and
te mpe rature . ESP are ge ne rally
c harac te rize d by highe r c apital
inve stme nts and lo we r o pe rating
c harge s, while the o ppo site may
be said fo r FF bagho use s. As a
c o nse que nc e , ESP pre se nt highe r
to tal c o sts whe n high spe c ific
c o lle c tio n are as are re quire d, as
happe ns in the c ase o f lo w-sulfur
high-re sistivity dust. Ho we ve r,
signific ant re duc tio ns in bo th
c apital inve stme nt and o pe rating
c harge s may be o btaine d with
pulse d e ne rgizatio n o f pre c ipitato rs wo rking in se ve re bac k
c o ro na c o nditio ns. This po ssibility
gre atly e nlarge s the fie ld o f
applic atio ns in whic h ESP are a
lo we r c o st o ptio n c o mpare d to
fabric filte rs. In the pape r an
e c o no mic c o mpariso n o f pulse
e ne rgize d ESP, with c o nve ntio nal
ESP, re ve rse -air, shake r, and
pulse -je t bagho use s is pe rfo rme d.
A mapping o f the o pe rating
c o nditio ns in whic h the ado ptio n
o f e ac h e xamine d c o ntro l te c hno lo gy is e c o no mic ally c o nve nie nt is
also de fine d.
Enviro nme ntal Manage me nt
and He alth
1 0 / 2 [ 1999] 9 6 –1 0 4
© MCB Unive rsity Pre ss
[ ISSN 0956-6163]
[ 96 ]
Introduction
Th e a doption of m or e a n d m or e str in gen t
pa r ticu la te em ission r e gu la tion s a n d th e
developm en t of im pr oved a ir -pollu tion con tr ol devices h ave r esu lted in th e in cr ea sed
a pplica tion of electr osta tic pr ecipita tor s
(E SP ) a n d fa br ic fi lter s (F F ). On e a r ea wh er e
both E SP a n d F F h ave a ch ieved m u ch w ider
u se is in th e con tr ol of pa r ticu la te em ission s
fr om in du str ia l a n d u tility coa l-fi r ed boiler s.
Th e m a jor pu r pose of th is stu dy is to iden tify
th e r a n ge of power pla n t oper a tin g con dition s
in wh ich E SP a n d F F fin d th eir optim a l u se
fr om a n econ om ic poin t of view. A su bsta n tia l
body of r esea r ch r esu lts h a s been pu blish ed
descr ibin g th e fa ctor s in fl u en cin g th e effectiven ess of E SP a n d F F, m u ch of wh ich h a s
been dir ected tow a r ds th e ch a r a cter iza tion of
coa l a sh pa r ticles a n d bu lk coa l a sh beh aviou r. For F F, th e coh esivity of th e a sh
deposited in th e du st ca k e is a k ey fa ctor
deter m in in g th e collection efficien cy a n d
filter clea n a bility (Bu sh et a l., 1986). Am on g
a sh es h avin g sim ila r pa r ticle size distr ibu tion , coh esivity is th e distin gu ish in g pa r ticu la te pr oper ty. Poor fi ltr a tion efficien cy h a s
been a ssocia ted w ith extr em ely low a sh coh esivity (Felix et a l., 1986). Coh esivity h a s been
cor r ela ted w ith coa l a n d a sh ch em istr y, fl u e
ga s tem per a tu r e a n d h u m idity, pa r ticle size
distr ibu tion a n d m or ph ology.
Th r ee ph en om en a in stea d a ffect th e over a ll
E SP per for m a n ce, n a m ely r e-en tr a in m en t in
th e ga s str ea m of collected pa r ticu la te du e to
r a ppin g of collectin g pla tes, ga s flow by-pa ssin g th e in ter -electr ode spa ce (sn ea k a ge) a n d
em ission of positive ion s by th e deposited
du st layer (ba ck cor on a ). However, a m a jor
fa ctor is th e a sh r esistivity wh ich in flu en ces
th e m igr a tion velocity. Ash r esistivity h a s
been sh ow n to depen d on coa l ch em istr y, ion
m obility, flu e ga s tem per a tu r e a n d h u m idity,
a s well a s th e con cen tr a tion of H 2O, O 2 a n d
SO 3 in th e flu e ga s (Bick elh a u pt, 1975). High
r esistivity (a bove 1011oh m cm ) m ay ca u se th e
on set of th e ba ck cor on a effect, in tr odu cin g
positive ion s in to th e ga s spa ce, th u s r edu cin g
th e pa r ticles ch a r ge a n d th e collection a bility
of th e E SP. In or der to solve th e ba ck cor on a
pr oblem th e m ost pr om isin g solu tion is
offer ed by th e pu lse or in ter m itten t en er giza tion wh er eby sh or t h igh volta ge pu lses a r e
su per im posed r epetitively on a DC ba se volta ge (Ha ll, 1990; La u sen , 1990; N elson a n d
Sa la soo, 1987). In th is w ay sign ifica n t
im pr ovem en ts of pa r ticle ch a r gin g a n d cu r r en t den sity distr ibu tion m ay be obta in ed
com pa r ed to con ven tion a l en er giza tion . Th is
r esu lts in th e elim in a tion of th e ba ck cor on a
ph en om en on a n d in a r edu ction of both th e
r equ ir ed specific collection a r ea (SCA) a n d
power con su m ption . However, th e cost of a
pu lse en er giza tion system is a bou t fou r tim es
gr ea ter com pa r ed to a con ven tion a l on e for
su pply of a pr ecipita tor w ith th e sa m e collectin g a r ea (La u sen , 1990). In pr eviou s wor k s
com pa r ison s between pu lsed a n d con ven tion a l E SP h ave been ca r r ied ou t by th e
a u th or s in differ en t in du str ia l a pplica tion s
(Ca pu to a n d Pela ga gge, 1997; Pela ga gge et a l.,
1996).
With th e a im of ver ifyin g th e effective a pplica tion fea sibility of pu lsed E SP in power
pla n ts, a stu dy on econ om ic ch a r a cter istics of
pu lsed E SP in com pa r ison w ith con ven tion a l
E SP a n d differ en t k in ds of fa br ic filter s h a s
been u n der ta k en . In th e pa per a ch a r a cter iza tion of str ea m s to be tr ea ted in coa l-fir ed
u tility pla n ts h a s been pr elim in a r ily ca r r ied
ou t. In th is w ay sign ifica n t oper a tin g scen a r ios h ave been defin ed in ter m s of du st r esistivity, collection efficien cy a n d pollu ted
str ea m flow r a te. Un der su ch h ypoth eses, a
com pa r a tive sizin g of pu lse en er gized a n d
con ven tion a l pla te-w ir e E SP, a n d sever a l
types of fa br ic filter s (sh a k er, r ever se-a ir, a n d
pu lse-jet clea n in g) h a s been th en per for m ed.
Th e sizin g of con ven tion a l E SP h a s been
ca r r ied ou t a ccor din g to a m odified liter a tu r e
m odel (Tu r n er et a l., 1988). Th e per for m a n ce
of th e pu lsed system h a s been in stea d eva lu a ted r esor tin g to ava ila ble liter a tu r e exper im en ta l da ta th a t fu r n ish th e va lu e of th e
Antonio C. Caputo and
Pac ific o M. Pelagagge
Ec o no mic c o mpariso n o f
pulse d e le c tro static
pre c ipitato rs and fabric filte rs
in c o al-fire d utility plants
Enviro nme ntal Manage me nt
and He alth
1 0 / 2 [1 9 9 9 ] 9 6 –1 0 4
efficien cy en h a n cem en t fa ctor (defin ed a s th e
r a tio between pu lsed a n d con ven tion a l effective m igr a tion velocity) a s a fu n ction of du st
r esistivity (Pela ga gge et a l., 1996). Sizin g of
fa br ic filter s h a s been per for m ed on th e ba sis
of liter a tu r e da ta a n d sta n da r d pr ocedu r es
(Tu r n er et a l., 1987). Cr iter ia for estim a tin g
ca pita l a n d a n n u a l cost fa ctor s h ave been
over viewed in th e pa per a ccor din g to sta n da r d pr a ctice (E PA, 1987; Va tavu k , 1990).
F in a lly, th e im pa ct of pu lse en er giza tion in
coa l-fir ed u tility pla n ts h a s been eva lu a ted
a n d th e oper a tin g con dition s in wh ich th e
a doption of ea ch exa m in ed con tr ol tech n ology is econ om ica lly con ven ien t h ave been
defin ed.
Operating scenario definition
Th e w idely va r ia ble coa l ch a r a cter istics in
ter m s of h ea tin g va lu e, su lfu r a n d a lk a li con ten t, com position , a sh con ten t, a n d r equ ir ed
com bu stion a ir, m a k e difficu lt a n y dir ect
com pa r ison between E SP a n d F F. In or der to
over com e th is pr oblem , th e str ea m to be
clea n ed h a s been ch a r a cter ized on ly r efer r in g to du st r esistivity a n d ga s flow r a te, in depen den tly fr om coa l type a n d boiler ca pa city.
Du st loa din g a n d size distr ibu tion h ave been
in stea d a ssu m ed w ith r efer en ce to pu lver ized
coa l boiler s. In pa r ticu la r, a n aver a ge m a ss
m ea n dia m eter of 15 µm h a s been h ypoth esized a t th e clea n in g device in let. Usu a l du st
loa din g for pu lver ized coa l boiler s r a n ges
between 2 a n d 7g/ m 3. Va lu es of 3 a n d 6g/ m 3
h ave been h er e a ssu m ed lea din g to a r equ ir ed
design collection efficien cy of 0.99 a n d 0.995
in or der to com ply w ith th e N SP S (N ew
Sou r ce Per for m a n ce Sta n da r d) lim its of
a bou t 30m g/ m 3. F lu e ga s tem per a tu r e h a s
been set a t 140°C.
Du st r esistivity in a ctu a l oper a tin g con dition s ca n be estim a ted by r esor tin g to liter a tu r e da ta or com pu ted a s a fu n ction of a sh
a n d fu m es com position , m oistu r e a n d tem per a tu r e. In th is wor k th r ee differ en t du st
r esistivity va lu es h ave been con sider ed: low
r esistivity (ρ = 1· 109oh m cm ), m ediu m (ρ =
1· 1011oh m cm ) a n d h igh r esistivity
(1· 1012oh m cm ) cor r espon din g to th e ca ses of
h igh , m ediu m a n d low su lfu r con ten t. F in a lly,
flow r a te va lu es fr om 50 u p to 800m 3/ s h ave
been con sider ed cor r espon din g to a boiler
size r a n gin g fr om 30 to 450MW.
ESP cost evaluation
E SP ca pita l a n d oper a tin g costs ca n be
dir ectly cor r ela ted to th e collectin g a r ea . A
fir st sim plified sizin g a ppr oa ch r elies on
estim a tion of th e effective pa r ticle m igr a tion
velocity fr om exper im en ts in pilot u n its or
fr om exper ien ce w ith sim ila r pla n ts. In th is
ca se th e r equ ir ed pla te a r ea ca n be obviou sly
obta in ed fr om th e cla ssic Deu tsch efficien cy
equ a tion a s m odified by Ma tts a n d Oh n feldt
(1973)
η =1− e
( − w SC A )k
(1)
wh er e w is th e effective m igr a tion velocity
(wh ich r a n ges fr om 2 to 40cm / s a ccor din g to
pr ecipita tor con figu r a tion , coa l type a n d ba ck
cor on a sever ity), η is th e collection efficien cy,
SCA is th e r a tio of collectin g a r ea (A) to
a ctu a l ga s flow r a te (Q), k is a coefficien t
m ea su r in g th e polydisper sion of pa r ticle size
distr ibu tion (u su a lly k = 0.5 a n d in cr ea ses u p
to 1 for m on odisper se pa r ticles).
In th is wor k th e sizin g pr ocedu r e pr oposed
by Tu r n er et a l. (1988) h a s been in stea d
a dopted to ta k e in to a ccou n t w ith gr ea ter
deta il losses der ivin g fr om flow sn ea k a ge a n d
r a ppin g r een tr a in m en t of collected pa r ticu la te. Ba ck cor on a effect h a s been con sider ed
by r edu cin g u p to a fa ctor 0.6 th e aver a ge
electr ic field ava ila ble for pa r ticle ch a r gin g
a n d m igr a tion . On ce deter m in ed th e r equ ir ed
pla te a r ea for a pr ecipita tor w ith con ven tion a l en er giza tion , th e a r ea of th e cor r espon din g pu lse en er gized pr ecipita tor is
sim ply defi n ed a s A p = A c / H (wh er e p sta n ds
for pu lsed a n d c for con ven tion a l). An efficien cy en h a n cem en t fa ctor H = w p / w c h a s
been a dopted to a ccou n t for th e in cr ea se in
effective pa r ticle m igr a tion velocity exper ien ced w ith pu lse en er giza tion . Cor r ela tion s
w ith du st r esistivity or w ith pr ecipita tor
pen etr a tion (Pela ga gge et a l., 1996; E P RI, 1986)
obta in ed by r esor tin g to ava ila ble liter a tu r e
exper im en ta l da ta ca n be em ployed to estim a te aver a ge va lu es of H. Her e th e follow in g
cor r ela tion h a s been a dopted (Pela ga gge et
a l., 1996):
ρ < 1 ⋅ 1011, H = 1
11
13
1 ⋅ 10 < ρ < 2 ⋅ 10 , H = ( 0.13881n ρ ) − 2.3468
(2)
ρ > 2 ⋅ 1013 , H = 2
However, it sh ou ld be n oted th a t con sider a ble
disper sion exists in exper im en ta l da ta a n d H
va lu es sh ow depa r tu r es u p to ± 50 per cen t
fr om th e aver a ge va lu es. Th e E SP fl a n ge to
fla n ge ba se cost ($) in clu din g sta n da r d
option s a n d in su la tion , a s a fu n ction of th e
collectin g a r ea is (Tu r n er et a l., 1988):
C = 5170.51 A 0.6276
C = 812.47A 0.8431
for A < 4600m 2
(3)
for A > 4600m 2 .
(4)
Th e cost of th e power su pply is
C P Sc = 0.12C
(5)
[ 97 ]
Antonio C. Caputo and
Pac ific o M. Pelagagge
Ec o no mic c o mpariso n o f
pulse d e le c tro static
pre c ipitato rs and fabric filte rs
in c o al-fire d utility plants
Enviro nme ntal Manage me nt
and He alth
1 0 / 2 [1 9 9 9 ] 9 6 –1 0 4
CP Sp = 0.45C.
(6)
Oth er costs (a u xilia r ies, in sta lla tion , in dir ect) m ay be a ssu m ed a s
C A = 1.53C
(7)
lea din g to th e follow in g tota l ca pita l in vestm en t (TCI)
TCI c = 2.65C
(8)
TCI p = 2.98C.
(9)
Dir ect a n n u a l costs ta k e a ccou n t of oper a tin g
la bor (OL), su per visin g la bor (SL), m a in ten a n ce la bor (ML), m a in ten a n ce m a ter ia ls
(MM) a n d en er gy cost (E ). Oper a tin g la bor
r equ ir em en t h a s been com pu ted a s 1 h r / sh ift
w ith a n h ou r ly r a te of $15/ h r, su per visin g
la bor h a s been con sider ed a s 15 per cen t of OL,
m a in ten a n ce m a ter ia ls cost h a s been ta k en a s
1 per cen t of equ ipm en t ba se cost C. Ma in ten a n ce la bor h a s been com pu ted a s 0.15
h r / week per ea ch 100m 2 of collectin g a r ea if A
> 4,650m 2, a n d 8h r / week wh en A < 4,650m 2.
Hou r ly m a in ten a n ce la bor r a te h a s been
a ssu m ed a s $18. E n er gy cost ($/ yr ) for fa n
oper a tion is
E F = 1.53( ∆p Q ) TYC E
(10)
wh er e ∆p is th e pr essu r e dr op a cr oss th e
equ ipm en t, Q (m 3/ s) is th e ga s flow r a te, T Y is
th e a n n u a l oper a tin g tim e (h r / yr ) a n d CE is
electr icity cost. It h a s been a ssu m ed ∆p = 250
P a , T Y = 8,640 h r / yr, C E = $0.06/ k Wh . F a ctor
1.53 a ccou n ts for a 65 per cen t fa n efficien cy.
E n er gy r equ ir ed for both cor on a disch a r ge,
in clu din g losses in T/ R sets, a n d r a pper s
oper a tion h a s been com pu ted by a ssu m in g a
specific power den sity P (con sider ed con sta n t
in th e exa m in ed efficien cy r a n ge) wh ich
differ s for con ven tion a l (P c = 20W/ m 2) a n d
pu lsed (P p = 12W/ m 2) E SP :
E D = P A TY CE .
(11)
As a r esu lt, th e dir ect a n n u a l costs a r e
DAC = OL + SL + ML + MM + E F + E D.
(12)
In dir ect a n n u a l costs (IDC) a r e expr essed a s
IDC = 0.6 (OL + SL + ML + MM) + 0.04 TCI. (13)
Ba sed on th e tota l ca pita l in vestm en t TCI a n d
th e oper a tin g a n n u a l costs AC = DAC + IDC,
th e tota l a n n u a l cost TAC h a s been eva lu a ted
su m m in g to th e oper a tin g costs th e ca pita l
r ecover y costs
TAC = AC + (TCI CRF )
(14)
wh er e th e ca pita l r ecover y fa ctor is
CRF =
[ 98 ]
i (1 + i ) N
(1 + i ) N − 1
(15)
w ith i th e a n n u a l in ter est r a te (i = 10 per cen t)
a n d N th e pla n t life (N = 20 yea r s). Costs of
a sh h a n dlin g equ ipm en t a n d disposa l, a s well
a s du ctwor k s a n d m a in fa n s h ave been
n e glected bein g com m on to both E SP a n d F F.
All equ ipm en t costs, ba sed on liter a tu r e cor r ela tion s, h ave been esca la ted to cu r r en t
va lu es r esor tin g, wh er e a pplica ble, to th e
P r odu cer P r ice In dex (P P I), th e Ma r sh a ll a n d
Sw ift cost in dex or th e Va tavu k Air Pollu tion
Con tr ol Cost In dexes (VAP CCI) pu blish ed
m on th ly in Ch em ica l En gin eer in g jou r n a l.
Fabric filter cost evaluation
Sever a l k in ds of clea n in g m eth ods h ave been
con sider ed, n a m ely r ever se-ga s (RGF F ),
sh a k er (SF F ) a n d pu lse-jet (P J F F ) fa br ic filter s. RGF F a n d SF F a r e ba sica lly sim ila r
except th a t RGF F a r e clea n ed in a gen tler w ay
th r ou gh a r ever se a ir flow wh ile SF F a r e
m ech a n ica ly sh a k en to obta in deposited du st
dislodgem en t. Th is en a bles a better clea n in g
of SF F ba gs r esu ltin g in a h igh er a llow a ble
per m ea tion velocity a t a given pr essu r e dr op
(h en ce a sm a ller filter in g a r ea ), bu t m ay
ca u se a sh or ter ba g life. P J F F in stea d a r e
clea n ed on -lin e w ith com pr essed a ir jets a n d
en a ble n ea r ly dou bled per m ea tion velocity
dr a stica lly cu ttin g th e r equ ir ed ba g a r ea .
However, on ly in r ecen t yea r s h ave P J F F been
w idely a ccepted in th e u tility in du str y (Belba
et a l., 1992; Dea n a n d Cu sh in g, 1988), a n d
cu r r en tly th e m a jor ity of ba gh ou ses in boiler
in sta lla tion s a r e still of th e RG k in d. A
deta iled a n a lysis of fa br ic filter s design a n d
oper a tion a l issu es m ay be fou n d in E P RI (1992
a -b).
Also in th e ca se of F F, costs a r e cor r ela ted
to filtr a tion a r ea (Tu r n er et a l., 1987). Th e
filter gr oss a r ea A (m 2) is com pu ted on th e
ba sis of th e r equ ir ed n et a r ea , dicta ted by th e
flow r a te a n d th e a llow a ble per m ea tion velocity (u su a lly descr ibed a s “a ir -cloth r a tio”,
ACR), su ita bly in cr ea sed th r ou gh a fa ctor F
a ccou n tin g for th e r equ ir ed extr a ba gs to be
in sta lled in or der to a llow off-lin e ba g
clea n in g:
Q
A=
F.
ACR
(16)
To eva lu a te fa ctor F th e follow in g cor r ela tion
h a s been u sed (a da pted fr om Tu r n er et a l.,
1987):
A < 16, 700m 2 , F = 2.06( A −0.0715 )
2
(17)
A > 16, 700m , F = 1.04.
In th e ca se of P J F F it is a lw ays F = 1. Ba sed on
typica l va lu es a dopted in th e u tility in du str y
for coa l fi r ed boiler s, th e selected ACR va lu es
Antonio C. Caputo and
Pac ific o M. Pelagagge
Ec o no mic c o mpariso n o f
pulse d e le c tro static
pre c ipitato rs and fabric filte rs
in c o al-fire d utility plants
Enviro nme ntal Manage me nt
and He alth
1 0 / 2 [1 9 9 9 ] 9 6 –1 0 4
for P J F F, RGF F, a n d SF F a r e 0.02, 0.01, 0.015
m / s r espectively (Belba et a l., 1992; E P RI, 1992
a -b; Sloa t et a l., 1993).
Th e com pu ted gr oss a r ea cor r espon ds to a
n u m ber of ba gs N B wh ich obviou sly depen ds
on ba g su r fa ce B S (N B = A / B S ). In th is wor k
th e follow in g u su a l ba g sizes h ave been con sider ed: 6.1 m lon g w ith 150m m dia m eter for
P J F F (B S = 2.87m 2), 9.75 m lon g w ith 300m m
dia m eter for both RGF F a n d SF F (BS =
9.19m 2) (Belba et a l., 1992; E P RI, 1992a b; Sloa t
et a l., 1993).
P u r ch a sed equ ipm en t cost (P E C) is gen er a lly com posed of th e ba gh ou se cost C B H , in su la tion cost C I , a n d tota l ba gs cost C BT . For
P J F F on ly, th e cost of th e ca ges su ppor tin g
th e ba gs C TC sh ou ld be a dded, wh ile for RGF F
th e cost of th e r ever se a ir fa n C RAF is to be
in clu ded. Ava ila ble cor r ela tion s for ba gh ou se
a n d in su la tion costs ($) a r e (Tu r n er et a l.,
1987):
m a ter ia l cost is a ssu m ed equ a l to ML cost. A
m a jor dir ect oper a tin g cost is ba g r epla cem en t con sider ed a s th e su m of a ctu a l ba g
cost, com pr isin g fr eigh t, a n d r epla cem en t
la bor. As ba gs a r e ch a n ged a t th e en d of th eir
u sefu l life B L , ba g r epla cem en t cost is essen tia lly a r epea ted in vestm en t th a t ca n be con sider ed a s u n ifor m ly distr ibu ted over th e
pla n t life by in tr odu cin g a pr oper ba g ca pita l
r ecover y fa ctor CRF B com pu ted over ba g life.
Ba g life a ssu m ed for P J F F, RGF F, SF F is 2.5,
fou r a n d th r ee yea r s r espectively (Belba et a l.,
1992; E P RI, 1992 a -b; Sloa t et a l., 1993). As a
con sequ en ce, th e equ iva len t a n n u a l ba g
r epla cem en t cost is expr essed a s
C ABR = CRFB CBR
(29)
for RGF F (930m 2< A < 7,430m 2)
C BH = 39479 + ( A 101.777)
is th e a ctu a l ba g r epla cem en t cost, w ith M LR
th e m a in ten a n ce la bor r a te ($/ h r ), B RT th e
ba g r epla cem en t tim e (7.5 m in u tes for P J F F
a n d 15 for oth er types).
E n er gy cost for fa n oper a tion ($/ yr ) ca n be
com pu ted a ccor din g to equ a tion 10. However,
pr essu r e dr op is th e su m of ba gh ou se pr essu r e dr op (a ssu m ed 400P a ) a n d “tu besh eet”
pr essu r e dr op a cr oss ba gs a n d du st ca k e. Th is
h a s been a ssu m ed a s 1,300, 1,500, 1,440P a for
P J F F, RGF F, a n d SF F r espectively (Belba et
a l., 1992; E P RI, 1992 a -b; Sloa t et a l., 1993). For
RGF F a lso th e en er gy for r ever se a ir fa n is to
be a ccou n ted for, con sider in g th a t it oper a tes
con tin u ou sly on a bou t 10 per cen t of th e gr oss
a r ea , w ith a n ACR typica lly 1.5 tim es th e
for w a r d ACR, a n d w ith a du st ca k e pr essu r e
loss of a r ou n d 1,620 P a . In ca se of SF F,
in stea d, en er gy cost E S ($/ yr ) for th e sh a k er
m ech a n ism is to be con sider ed, given by
E S = 0.5704 A ( T Y / 8760) CE .
(31)
C I = 1523 + ( A 11.6206)
for P J F F (370m 2< A < 1,300m 2)
C BH = 63727 + ( A 106.3683)
C I = 4045 + ( A 30.1661)
for SF F (370m 2< A < 5,570m 2)
C BH = 50567 + ( A 108.4668)
C I = ( A 4.8659)
(18)
(19)
(20)
(21)
(22)
(23)
a n d, for la r ge sized ba gh ou ses, in depen den tly
fr om clea n in g m eth od (9,290m 2< A < 37,160m 2)
C BH = 303404 + ( A 80.1369)
(24)
CI = 81150 + ( A 9.2466).
(25)
Tota l ba gs cost is C BT = C B A wh er e C B is th e
specific ba g cost ($/ m 2). C B va lu es of 32 a n d
$8.7/ m 2 h ave been a ssu m ed for P J F F, a n d
eith er RGB or SF F (Va tavu k , 1990; Sloa t,
1993). Sta in less steel ca ge cost C C ($) is cor r ela ted to ba g su r fa ce w ith :
CC = 12.201 + ( B S 2.267).
(26)
Tota l ca ges cost ($) is C TC = N B C C . Rever se a ir
fa n cost ($) is C RAF = 411.38 Q.
P u r ch a sed equ ipm en t cost, in clu din g
in str u m en ta tion , ta xes, a n d fr eigh t, is:
P E C = 1.18 (CBH + CI + CBT + CRAF + CTC )
(27)
wh ich , con sider in g in sta lla tion costs, lea ds to
a TCI given by
(28)
TCI = 2.17 P E C.
For wh a t con cer n s OL costs a r equ ir em en t of
2 h r / sh ift is con sider ed, wh ile ML is com pu ted a ssu m in g 1h r / sh ift. SL cost is com pu ted a s seen for E SP wh ile m a in ten a n ce
wh er e
CBR = [ ( M LR 1.6 N B ( B RT / 60) + (1.08 A CB )]
(30)
F in a lly, a llow a n ce sh ou ld be m a de for P J F F
com pr essed a ir r equ ir em en t th a t ca n be com pu ted on th e ba sis of 0.002m 3/ s (STP ) of com pr essed a ir per u n it ga s flow r a te a t a cost of
$25.4/ h r per u n it com pr essed a ir flow r a te
(STP ).
In dir ect a n n u a l costs a r e com pu ted a s
descr ibed for E SP. Tota l a n n u a l costs a r e
com pu ted exclu din g CBR fr om th e ca pita l
r ecover y a s ba g cost is a lr ea dy com pu ted in
oper a tin g costs:
(32)
TAC = AC + [ (TCI -CBR ) CRF ].
Economic analysis
A pa r a m etr ic a n a lysis ba sed on ga s flow r a te,
pr ecipita tor efficien cy a n d du st r esistivity
h a s been per for m ed eva lu a tin g th e
[ 99 ]
Antonio C. Caputo and
Pac ific o M. Pelagagge
Ec o no mic c o mpariso n o f
pulse d e le c tro static
pre c ipitato rs and fabric filte rs
in c o al-fire d utility plants
Enviro nme ntal Manage me nt
and He alth
1 0 / 2 [1 9 9 9 ] 9 6 –1 0 4
cor r espon din g tota l ca pita l in vestm en t (TCI),
a n n u a l oper a tin g costs (AC), a n d tota l a n n u a l
costs (TAC) for th e five a ir pollu tion con tr ol
devices con sider ed. In ca se of F F, n o a ttem pt
to eva lu a te costs ou tside th e decla r ed va lidity
r a n ge of ava ila ble cor r ela tion s h a s been
m a de. Th er efor e, n ot a ll k in ds of F F h ave
been sized a n d costed over th e en tir e fl ow r a te
r a n ge. However, for la r ge fl ow r a tes, i.e. la r ge
ba gh ou ses, th e flow r a te h a s been split
between two pa r a llel u n its th a t h ave been
sin gu la r ly costed, givin g r ise to th e discon tin u ities a ppea r in g in th e figu r es.
F igu r e 1 depicts th e TCI a ccor din g to th e
two con sider ed efficien cy va lu es. In th e ca se
of low r esistivity coa l (F igu r e 1a ), wh er e n o
ben efit in effective m igr a tion velocity ca n be
expected fr om pu lsed en er giza tion , th e collectin g pla te a r ea is th e sa m e (SCA = 45.2 a n d
56.2s/ m depen din g on efficien cy) a n d pu lsed
E SP r esu lts m or e expen sive du e to th e h igh er
cost of th e power su pply u n its. P J F F a n d SF F
Figure 1
To tal c apital inve stme nt: (a) lo w, (b) high
re sistivity
[ 100 ]
sh ow r ou gh ly th e sa m e cost, wh ich is less
th a n RGF F ca pita l in vestm en t du e to th e
lower r equ ir ed ba g a r ea th a n k s to th e h igh er
a llow a ble ACR. In pa r ticu la r, th e effects of
size r edu ction is eviden t for P J F F wh ich a r e
ch a r a cter ized by th e lowest ca pita l cost even
if th e specific ba g cost is h igh er, wh ile RGF F
sh ow th e h igh est ca pita l cost. In th e ca se of
m ediu m r esistivity du st th e lower SCA of
pu lsed E SP (SCA c = 50.4s/ m , SCA p = 43s/ m a t
low efficien cy, wh ile SCA c = 62.6s/ m , SCA p =
53.4s/ m a t h igh efficien cy) is offset by th e cost
of th e en er giza tion equ ipm en t r esu ltin g in
n ea r ly equ iva len t TCI of both pr ecipita tor
types. Ben efits a r isin g fr om pu lsed en er giza tion fu lly sh ow in stea d in ca se of h igh r esistivity du st wh er e th e r edu ced pla te a r ea (F igu r e 1b: SCA c = 75.6 s/ m , SCA p = 50.7 s/ m
wh en efficien cy is 0.99 or SCA c = 93.9 s/ m ,
SCA p = 63 s/ m wh en efficien cy is 0.995) fu lly
offsets th e in cr ea sed cost of power su pply a n d
th e opposite situ a tion w ith r espect to F igu r e
1a is obser ved wh en com pa r in g E SP costs,
r esu ltin g in th e con ven tion a l E SP becom in g
th e h igh est in vestm en t option , wh ile th e
pu lsed E SP r em a in s com petitive w ith th e
RGF F. However, a s fa r a s ca pita l costs a r e
con cer n ed, P J F F a n d SF F r esu lt a lw ays th e
lowest cost option u n less a lower E SP efficien cy is specified.
Wh en oper a tin g costs a r e con sider ed (F igu r es 2a a n d b, r efer r in g r espectively to low
a n d h igh du st r esistivity) pu lsed E SP costs
a r e a lw ays lower th a n con ven tion a l E SP du e
to th e lower specifi c cor on a power, even in
ca se of low r esistivity coa l. Th e cost savin g
in cr ea ses a s du st r esistivity r ises du e to th e
a dded ben efit of a r edu ced pla te a r ea (F igu r e
2b). Mor eover, E SP a n n u a l costs a r e lower
th a n cor r espon din g costs of F F wh ich a r e
pen a lized by th e per iodica l ba g r epla cem en t.
On ly in ca se of ver y h igh r esistivity coa l
(F igu r e 2b) a n d h igh efficien cy th e r esu ltin g
collectin g a r ea of con ven tion a l E SP m ay lea d
to costs gr ea ter th a n th a t sh ow n by fa br ic
filter s (SF F ). P J F F a n d RGF F exper ien ce th e
h igh est oper a tin g costs a m on g F F, in th e fir st
ca se du e to th e sh or ter ba g life a n d th e m u ch
h igh er specific ba g cost, a n d in th e la tter ca se
ow in g to th e m u ch h igh er filter in g su r fa ce,
wh ile SF F sh ow lower cost in r espect to RGF F
du e to th e lower r equ ir ed a r ea (h igh er a llow a ble ACR) even if ba g life is sh or ter.
F in a lly, th e tota l a n n u a l cost, in clu din g
ca pita l r ecover y, is a n a lyzed in F igu r es 3 a n d
4. Th is is th e m a in econ om ic pa r a m eter th a t
m ay h elp in th e ch oice of th e lowest cost pollu tion con tr ol option . F igu r e 3 depicts TAC in
th e ca se of low E SP efficien cy (99 per cen t)
wh ile F igu r e 4 r efer s to h igh collection efficien cy (99.5 per cen t). In th is ca se th e cou n ter a ctin g effects of lower ca pita l costs a n d
Antonio C. Caputo and
Pac ific o M. Pelagagge
Ec o no mic c o mpariso n o f
pulse d e le c tro static
pre c ipitato rs and fabric filte rs
in c o al-fire d utility plants
Figure 2
Annual o pe rating c o sts: (a) lo w, (b) high
re sistivity c o al
Figure 3
To tal annual c o sts: ESP e ffic ie nc y (0 .9 9 ); (a)
lo w, (b) me dium, (c ) high re sistivity c o al
h igh er oper a tin g ch a r ges for F F a r e
eviden ced, wh ile th e opposite ca n be sa id for
E SP. P J F F a n d SF F sh ow sim ila r costs,
m a r k edly less th a n RGF F du e to th e lower
r equ ir ed ba g a r ea th a n k s to th e h igh er a llow a ble ACR. Th is expla in s th e su ccess r ecen tly
en cou n ter ed by P J F F in u tility a pplica tion s
n ow th a t th is tech n ology is fu lly m a tu r e. In
pa r ticu la r P J F F TAC is sligh tly la r ger th a n
SF F, in spite of th e su per ior size r edu ction
effect, du e to a h igh er oper a tin g cost ca u sed
by th e sh or ter ba g life a n d th e m u ch h igh er
specific ba g cost.
As fa r a s E SP a r e con cer n ed a distin ction
h a s to be m a de between low a n d m ediu m to
h igh du st r esistivity. In fa ct, a s a con sequ en ce
of th e obser ved tr en ds in E SP ca pita l a n d
oper a tin g costs, th e pu lsed type is a lw ays
con ven ien t in r espect of con ven tion a l E SP in
ca se of m ediu m to h igh r esistivity, bu t n ot in
ca se of low r esistivity (F igu r es 3a , 4a ). With
low r esistivity coa l pu lsed or con ven tion a l
E SP a r e a lower cost option com pa r ed to F F
(F igu r es 3a , 4a ) bu t th is com petitive m a r gin
r edu ces a s th e r equ ir ed efficien cy in cr ea ses.
In m ediu m r esistivity coa l a pplica tion s con ven tion a l E SP a r e still a com petitive option ,
w ith pu lsed E SP bein g in stea d a lower cost
option in com pa r ison w ith F F. In th e ca se of
h igh r esistivity in stea d (F igu r es 3c, 4c)
con ven tion a l E SP a r e a lw ays m or e costly
Enviro nme ntal Manage me nt
and He alth
1 0 / 2 [1 9 9 9 ] 9 6 –1 0 4
[ 101 ]
Antonio C. Caputo and
Pac ific o M. Pelagagge
Ec o no mic c o mpariso n o f
pulse d e le c tro static
pre c ipitato rs and fabric filte rs
in c o al-fire d utility plants
Figure 4
To tal annual c o sts: ESP e ffic ie nc y (0 .9 9 5 ); (a)
lo w, (b) me dium, (c ) high re sistivity c o al
Enviro nme ntal Manage me nt
and He alth
1 0 / 2 [1 9 9 9 ] 9 6 –1 0 4
th a n fa br ic fi lter s (especia lly P J F F a n d SF F ),
w ith pu lsed E SP bein g less costly a t low efficien cy a n d com petitive a t h igh efficien cy. In
con clu sion , a t low to m ediu m r esistivity both
k in ds of E SP a r e com petitive or con ven ien t
in r espect to F F, wh ile a t h igh r esistivity
on ly pu lsed E SP is eith er com petitive or
[ 102 ]
con ven ien t a ccor din g to th e flow r a te to be
tr ea ted a n d th e r equ ir ed efficien cy. RGF F ca n
be con sider ed com petitive w ith E SP on ly a t
h igh r esistivity a n d m ay r esu lt in bein g con ven ien t a t h igh efficien cy. In th e com pa r ison
of con ven tion a l E SP w ith RGF F a n d P J F F
su ch r esu lts a r e in a ccor da n ce w ith th ose of
ea r lier stu dies (E P RI, 1985, 1992c; Sloa t et a l.,
1993), even if th e n u m er ica l r esu lts a r e n ot
dir ectly com pa r a ble du e to differ en ces in th e
a ssu m ed econ om ic pr em ises; m or eover, som e
pieces of equ ipm en t a n d a n n u a l costs h ave
h er e been n e glected, bein g com m on to a ll
k in ds of devices.
In th e pr esen t a n a lysis th e cost eva lu a tion
h a s been per for m ed on th e ba sis of aver a ge or
typica l va lu es of th e oper a tin g pa r a m eter s.
However, pr esen t r esu lts a r e in dica tive a n d
va lid on ly u n der th e pr eviou sly sta ted
a ssu m ption s. In fa ct, site specifi c con dition s
m ay h eavily m odify th e econ om ic com pa r ison lea din g to va lu es of th e design pa r a m eter s su bsta n tia lly differ en t fr om th ose
a ssu m ed. As a n exa m ple, F igu r e 5 sh ow s th e
w ide TAC r a n ge th a t ca n ch a r a cter ize F F.
Upper a n d lower bou n ds of th e sh a ded a r ea
r epr esen t th e ca ses of pessim istic a n d optim istic design . For th e sa k e of sim plicity on ly
th e follow in g pa r a m eter s’ va r ia tion s h ave
been con sider ed (Belba et a l., 1992; Dea n a n d
Cu sh in g, 1988; E P RI, 1992b): tu besh eet pr essu r e dr op (P J F F : 480 to 2910P a ; RGF F : 890 to
1970P a ; SF F : 1060 to 1970P a ), a ir -cloth r a tio
(P J F F : 0.015 to 0.03m / s; RGF F : 0.007 to
0.011m / s; SF F : 0.012 to 0.016m / s), a n d ba g life
(P J F F : 1 to 5 yea r s; RGF F : 3 to 5 yea r s; SF F : 2
to 4 yea r s), wh ile th e possible va r ia tion of
fa br ic m a ter ia l a n d th e va r ia tion of its specific cost w ith ba gs dim en sion s a n d life h ave
been n e glected. Mor eover, in P J F F th e specific com pr essed a ir con su m ption h a s n ot
been cor r ela ted w ith aver a ge tu besh eet pr essu r e dr op n or h a s th e effect of clea n in g pu lse
pr essu r e been con sider ed.
F in a lly, th e pr oper ties of bu r n ed coa l h eavily in flu en ce th e ch oice of th e con tr ol device
for a given boiler size. As a n a pplica tion
exa m ple of th e m a ppin g r esu ltin g fr om th e
pr esen t stu dy, th e ca se of a 250MW boiler
fir in g th r ee differ en t coa ls is pr esen ted. Th e
ca lcu la ted va lu es of Ta ble I sh ow h ow th e
econ om ic ch oice is dicta ted by specific oper a tin g con dition s. Coa l a n d boiler ch a r a cter istics h ave been obta in ed by liter a tu r e da ta
(E P RI, 1985, 1992c). Th e cost va lu es m ay be
a lso eva lu a ted by dir ect in spection of figu r es
a n a logou s to th e pr eviou s on es, bu t com pu ted
for th e r equ ir ed E SP efficien cy a n d r esistivity, en ter in g w ith th e pr oper flow r a te. TAC
va lu es sh ow n in Ta ble I sh ow th a t for a low
r esistivity coa l lik e N or th Da kota lign ite, th e
con ven ien t ch oice is a con ven tion a l E SP even
Antonio C. Caputo and
Pac ific o M. Pelagagge
Ec o no mic c o mpariso n o f
pulse d e le c tro static
pre c ipitato rs and fabric filte rs
in c o al-fire d utility plants
in spite of th e h igh efficien cy r equ ir ed. For a
m ediu m r esistivity coa l in stea d (Appa la ch ia n
low su lfu r ) a pu lsed E SP (or a n SF F ) wou ld be
pr efer a ble even if a lower collection
efficien cy is r equ ested. F in a lly, in ca se of h igh
r esistivity du st (Wyom in g Pow der River
Ba sin coa l) th e lowest cost option wou ld be a n
SF F, w ith pu lsed E SP a n d P J F F sh ow in g
sim ila r bu t h igh er tota l costs.
Figure 5
Fabric filte rs to tal annual c o st range : (a)
re ve rse air, (b) shake r, (c ) pulse je t
Enviro nme ntal Manage me nt
and He alth
1 0 / 2 [1 9 9 9 ] 9 6 –1 0 4
Conclusions
In th is pa per a n econ om ica l com pa r ison
between pu lsed E SP a n d con ven tion a l E SP,
r ever se a ir, sh a k er, a n d pu lse-jet fa br ic filter s
h a s been ca r r ied ou t in th e coa l-fir ed boiler
a r ea . In th e ca se of low r esistivity du st, cor r espon din g to h igh su lfu r coa ls, con ven tion a l
E SP r esu lts econ om ica lly con ven ien t w ith
r espect to F F especia lly wh en th e ga s flow
r a te in cr ea ses. Th is is fu r th er con fir m ed
con sider in g r edu ced du st loa din g of th e
str ea m , givin g r ise to lower design collection
efficien cy. For m ediu m r esistivity coa l, econ om ic con ven ien ce of pu lsed E SP h a s been
poin ted ou t. Also in th is con dition , con ven ien ce of pu lsed E SP im pr oves wh en du st
loa din g decr ea ses a n d ga s flow r a te gr ow s.
Wh en low su lfu r coa ls a r e bu r n ed th e r esu ltin g h igh r esistivity du st defin itively pen a lizes th e con ven tion a l E SP. F F sh ow gen er a lly
better econ om ic r esu lts, w ith th e exception of
RGF F, even wh en com pa r ed to pu lsed E SP a t
lea st a s lon g a s h igh efficien cy is r equ ested
a n d F F per for m a ccor din g to design specifi ca tion s. F r om th is poin t of view fu r th er
r esea r ch effor ts h ave to be a im ed a t th e a n a lysis of coa l coh esivity effects on F F per for m a n ces a n d costs.
References
Belba , V.H., Gr u bb, V.T. a n d Ch a n g, R.L. (1992),
“Th e poten tia l of pu lse-jet ba gh ou ses for
u tility boiler s. P a r t 1”, J ou r n a l of th e A ir
Wa ste M a n a gem en t A ssocia tion , Vol. 42 N o. 2,
pp. 209-217.
Bick elh a u pt, R.E . (1975), “E ffect of ch em ica l com position on su r fa ce r esistivity of fl y a sh ”, E PA
r epor t 600/ 2-75-017.
Table I
Influe nc e o f c o al c harac te ristic s
Coal type
North Dakota
lignite
Appalachian
low sulfur
Wyoming
Powder River
Dust load Flow rate
ESP
Resistivity SCA(c) SCA(p)
Total annual cost ($M / year)
(g/ m3 )
(m3 / s) efficiency (ohm cm) (s/ m) (s/ m) ESP(c) ESP(p) PJFF RGFF
SFF
6.13
537.5
0.9951
1 × 10 9
56.5
56.5
2.63
2.77
2.98
3.40
2.77
3.98
412.9
0.9924
1 × 10 11
61.4
52.4
2.24
2.07
2.33
3.10
2.09
4.97
484.0
0.9939
1 × 10 12
89.4
59.9
3.52
2.66
2.70
3.55
2.40
[ 103 ]
Antonio C. Caputo and
Pac ific o M. Pelagagge
Ec o no mic c o mpariso n o f
pulse d e le c tro static
pre c ipitato rs and fabric filte rs
in c o al-fire d utility plants
Enviro nme ntal Manage me nt
and He alth
1 0 / 2 [1 9 9 9 ] 9 6 –1 0 4
[ 104 ]
Bu sh , P.V., Sn yder, T.R. a n d Ch a n g, R.L. (1986),
J ou r n a l of th e A ir Pollu tion Con trol A ssocia tion , Vol. 39 N o. 228.
Ca pu to, A.C. a n d Pela ga gge, P.M. (1997),
“E con om ic a n a lysis of pu lsed vs con ven tion a l
E SP s in in du str ia l a pplica tion s”,
En viron m en ta l M a n a gem en t a n d Hea lth , Vol.
8 N o. 3, pp. 100-4.
Dea n , A.H. a n d Cu sh in g, K.M. (1988), “Su r vey on
th e u se of pu lse-jet fa br ic fi lter s for coa l-fi r ed
u tility a n d in du str ia l boiler s”, J ou r n a l of th e
A ir Pollu tion Con trol A ssocia tion , Vol. 38 N o.
1, pp. 90-6.
E lectr ic Power Resea r ch In stitu te (1986), A n In v estiga tion of Precipita tor Pu lse En ergiz a tion ,
E P RI CS-4717.
E n vir on m en ta l P r otection Agen cy (1987), Econ om ic A n a lysis B ra n ch Con trol Cost M a n u a l,
E PA 450/ 5-87-001A (P B87-166583).
Felix, L.G., Mer r itt, R.L. a n d Du n ca n , W.S. (1986),
J ou r n a l of th e A ir Pollu tion Con trol A ssocia tion , Vol. 36, N o. 1075.
Ha ll, H.J . (1990), “Histor y of pu lse en er giza tion in
electr osta tic pr ecipita tion ”, J ou r n a l of
Electrosta tics, Vol. 25, pp. 1-22.
La u sen , P. (1990), “Applica tion of pu lse en er giza tion on elecr osta tic pr ecipita tor s for va r iou s
pr ocesses”, J ou r n a l of Electrosta tics, Vol. 25,
pp. 41-53.
Ma tts, S. a n d Oh n feldt, P.O. (1973), “E fficien t ga s
clea n in g w ith SF electr osta tic pr ecipita tor s”,
A B S v en sk a Fla k t T ech . B u ll.
N elson , J .K. a n d Sa la soo, L. (1987), “Th e im pa ct of
pu lse en er giza tion on electr osta tic pr ecipita tion per for m a n ce”, IEEE T r. on Electr ica l
In su la tion , Vol. E I-22 N o. 6, pp. 657-75.
Pela ga gge, P.M., Ca pu to, A.C. a n d Gia cch etta , G.
(1996), “E con om ic im pa ct of electr osta tic
pr ecipita tor s pu lse en er giza tion on dedu stin g
in ir on -or e sin ter in g pla n ts”, En viron m en ta l
M a n a gem en t a n d Hea lth , Vol. 7 N o. 5, pp. 21-6.
Tu r n er, J .H., Vin er, A.S., McKen n a , J .D., J en k in s,
R.E . a n d Va tavu k , W.M. (1987), “Sizin g a n d
costin g of fa br ic filter s”, J ou r n a l of th e A ir
Pollu tion Con trol A ssocia tion , Vol. 37, P a r t 1:
N o. 6, pp. 749-59; P a r t 2: N o. 9, pp. 1105-12.
Tu r n er, J .H., Law less, P.A., Ya m a m oto, T., Coy,
D.W., Gr ein er, G.P., McKen n a , J .D. a n d
Va tavu k , W.M. (1988), “Sizin g a n d costin g of
electr osta tic pr ecipita tor s”, J ou r n a l of th e A ir
Pollu tion Con trol A ssocia tion , Vol. 38, P a r t 1:
N o. 4, pp. 459-72; P a r t 2: N o. 5, pp. 715-26.
Va tavu k , W.M. (1990), Estim a tin g costs of A ir Pollu tion Con trol, Lew is P u blish er s, Ch elsea , MI.
Further reading
E lectr ic Power Resea r ch In stitu te (1985), Econ om ics of Fab r ic Filters a n d Electrosta tic Precipita tors – 1984, E P RI CS-4083.
E lectr ic Power Resea r ch In stitu te (1992a ), Fab r ic
Filters for th e Electr ic Utility In d u str y – Vol. 1:
Gen era l Con cepts, E P RI CS-5161.
E lectr ic Power Resea r ch In stitu te (1992b), Fab r ic
Filters for th e Electr ic Utility In d u str y – Vol. 5:
Gu id elin es for Fab r ic Filter Design , E P RI CS5161.
E lectr ic Power Resea r ch In stitu te (1992c), Econ om ic Eva lu a tion of Pa r ticu la te Con trol T ech n ologies: N ew Un its, E P RI TR-100748.
Sloa t, D.G., Ga ik w a d, R.P. a n d Ch a n g, R.L. (1993),
“Th e poten tia l of pu lse-jet ba gh ou ses for
u tility boiler s. P a r t 3: com pa r a tive econ om ics
of pu lse-jet ba gh ou se, pr ecipita tor s a n d
r ever se-ga s ba gh ou ses”, J ou r n a l of th e A ir
Wa ste M a n a gem en t A ssocia tion , Vol. 43 N o. 1,
pp. 120-8.