Makalah Convection Section Cleaning 4.doc

7/26/2019 Makalah Convection Section Cleaning 4.doc

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Cleaning of Primary Reformers Convection Section andCombustion Chambers Firebrick Coating

Sukardi, Hari Supriyadi and Process Engineering TeamPT. Kaltim Parna Industri

Plant Site, Kaltim Industrial EstateBontang, East Kalimantan, 7531

Email! sukardi"kpi#co#id$ [email protected] $ [email protected]

Abstract PT. Kaltim Parna Industry, a Joint Venture Company between Indonesian and Japanese

companies, is operating single train 1500 T ! name plate capacity ammonia plant in "ontang, #ast Kalimantan o$ Indonesia. T%e plant %as been entering into commercial production since &ebruary,'00' and almost o$ t%e entire product was mainly e(ported to international mar)et. T%e plant is built using T*P+*# s license, in combination wit% "-+& s C* ' remo al and -ir Product s purge gasreco ery.

T*P+*# s primary re$ormer consists o$ %eat e(c%anger stac)s on top o$ t%e $urnace, in order to $acilitate %eat reco ery. !ue to %eat duty re/uirement and per%aps by t%e assumption t%at nocleaning is necessary, t%e arrangement is so tig%t lea ing almost no space $or %uman mo ement inbetween.

KPI e(perienced se ere $ouling on t%e $lue gas side o$ t%ese %eat e(c%angers. T%is is on outer tubes side, w%ic% some are $inned tubes. -lt%oug% t%e cause %as not clearly identi$ied, laboratoryanalysis indicates t%at t%e $ouling is %a ing similar composition wit% t%e $irebric) contains +ilica .T%ere$ore, preliminary assumption o$ w%at causes t%e problem is silica e aporation $irebric) erosion .

2e de eloped cleaning met%od and also special tools to do t%e cleaning and %a e applied it success$ully. Per$ormance %as been impro ed by '.513 and since t%en, periodical cleaning during turnaround is always been conducted.

In order to completely eliminate $ouling source and in t%e %ope to reduce cleaning $re/uency,we plan to coat combustion c%amber wit% special %ig% temperature resistance coating. +ome specimen

%as been applied near our side4$ired burners and its resistance against erosion %as been monitored since &ebruary '005.T%e result is promising t%at t%e material is stable against %ig% temperature and e en $urt%er

%elps t%e operation. T%e coating acted as %eat re$lector $rom burner to re$ormer tubes. eat loss to surrounding %as decreased as seen $rom decreased outside wall temperature. In o erall, $uel consumption %as been decreased by 166 7m 6 %. - $ull scale implementation will be conducted in t%ene(t 7o ember Turn -round.

T%is paper will s%are our e(perience battling $ouling problem, operation ad8ustments totemporary o ercome t%e trouble, cleaning met%od o$ t%e con ection section %eat e(c%angers and t%eresult o$ t%e coating e(periment in t%e primary re$ormer.

Key%ords!& 'on(ection Section ! )pper section o* t+e *urnace radiant section-, a group o* +eat e.c+anger stacks used *or

reco(ering +eat *rom t+e *lue gas#& /ouling ! P+enomena o* dirt attac+es to t+e sur*ace o* +eat e.c+anger0s tu es# In t+is paper, it isinterc+angea ly used in its (er s *orm t+e p+enomena- and noun t+e material-#

& 2arnet ! atural mined sand, mainly contains 4lmandine ore Iron 4luminum Silicate,/e 34l Si6 -3-, used in sand lasting#

& point no le ! Specially prepared in&+ouse- no le used in sand lasting, made o* stainless steel t+at+as *our outlet#

& /urnace coating ! 8irconium ased coating, e.posa le to +ig+ temperature as inside t+e *urnace# T+ere aret%o types! non&(itreous and (itreous# Ho%e(er, t+is paper re*ers to non&(itreous type only#

INTROD !TIONKPI0s Primary 9e*ormer is duple. c+am er re*ormer +a(ing t%o parallel *urnaces- %it+ a single *lue

gas duct, designed y Haldor Topsoe# T+e re*ormer +as t%o inlet distri utors and a single cold collector or

trans*er line, %+ic+ is connected to catalyst tu es y a num er o* +ot su &collectors and pigtails# 'om ustion air
mailto:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]


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is introduced to t+e urners using t%o induce dra*t *ans located in t+e top o* *lue gas duct t+at also keeps *urnacec+am er in (acuum#

T+e *urnace is di(ided into t%o sections! radiant and con(ection section# 9adiant section is located int+e lo%er part o* t+e *urnace %+ere t+e urners and catalyst tu es are located# 'on(ection section is located int+e upper side ad:acent to t+e radiant section# In t+e con(ection section, some +eating to gas process streams aretaking place, reco(ering +eat *rom t+e *lue gas, as *ollo% *rom ottom to top-!

"#at $%chang#rs&ar# Tub#&as#' m (

Tub# )ur*ac#Ratio

Total Ar#a'm ( R#marks

E&; ;1re*ormer0s *eed gas pre+eater- 3 1#;; 3 Bare# 1 undle

E&; ; 4nd process air pre+eater- 1< #3 1#;; 1< #3 Bare# 1 undle

E&; ;3&1steam super+eater- >7=#;; 1#;; >7=#;; Bare# undles

E&; ;3&steam super+eater- 3 =#>; 1 #>; ,15 #=> /inned# 1 undle

E&; ; 43rd natural gas pre+eater- 3;#;; #;< 7


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d# Increasing H @ ratio in t+e synt+esis loop *rom 3#; to 3#5, in order to reduce ?uantity o* *uel o**&gas *rom t+eHydrogen 9eco(ery )nit# T+is *uel gas contains +ig+ inert itrogen-, %+ic+ %ill act as additional +eat carrier int+e *lue gas and carrying t+e +eat to upper side coils#

# ecreasing HP steam temperature *rom steam super+eater coil, E&; ;3, *rom normal (alue 515 ' to around#

/$T"OD$ AND TOO+)

Convection Section Cleaning 'leaning met+od is y sand lasting using garnet sand# It is applied due to c+aracteristic o* *ouling and

con(ection section0s en(ironment# 2enerally, *ouling is loosely attac+ed to t+e tu es unless *or E&; ;1 up to E&; ;3, t+e ottom e.c+angers-, ut too sticky *or air lo%ing# 6n t+e ot+er +and, re*ractory material is sensiti(eto %ater %et cleaning met+od-#

2arnet ;@ ; mes+ 5


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End tu e protection is installed according to t+e *ollo%ing se?uence!

Side protection installation is :ust a simple insertion o* t+e can(as&tarpaulin# 4 %ire is re?uired in t+e eginning,to guide t+e tarpaulin do%n# In our e.perience, salient portion o* t+e re*ractory is strong enoug+ to +andle t+e*riction and %ill not collapse#

# Installation o* %aste trap on e(ery 3 ro%s e.c+angersCaste trap is essential in order to e a le reco(ering used garnet *or recycle# T+e s+orter placement in

et%een, %ill result in etter reco(ery# Ho%e(er, installation time %ill also take longer# Here, e(ery t+ree ro%s isa compromise et%een t+ese *actors#3# Sand lasting *rom upper and lo%er side o* tu e anks

ue to tu es arrangement, sand lasting is conducted *rom t%o sides, upper and lo%er part# T+e special points no le is (ery +elp*ul to speed up t+e cleaning# Sketc+ o* sand last direction is as *ollo%!

# 4ir lo%ing *or garnet reco(ery and *inal cleaning4lt+oug+ garnet is relati(ely dust *ree, +o%e(er *ouling material is ecoming dust a*ter lasting# In

order to pre(ent t+e dust attac+ to t+e tu es again, air is lo% into t+e tu es using t+e same no le# In t+e sametime, lo%er air&out position- is used to catc+ some *lying dusts# T+is %ill also pus+ t+e remaining garnetdo%n%ards# 9eco(ered garnet on t+e %aste trap is t+en separated *rom t+e *ouling material y (acuuming t+edust, %+ic+ is t+en re&utili ed *or lasting until t+ree recycles#

/or t+e a o(e %orks, re?uired e?uipments are as *ollo%!

No $0uipm#nt 1ty. )p#ci*ications

1 'ompressor 1 ea Engine! 5; c*m$ %eig+t! ton$im! 1#5.3.1#5 m# P disc+! 1; kg@cm 2

Sand last pot ea'apacity 3;; liter$ %eig+t! 5;; kg$

im! ;#5. m

3 Gacuum mac+ine 1 ea Blo%er ea

5 point no le ; ea 4s per dra%ing> Hand grip *or no le ea 4s per dra%ing7 Caste trap 1 set Plastic tarpaulin< Sand last +ose set D! 15; m$ ! 3@= 9e*ractory protection end tu e- 1 set Ply%ood 5 mm, to e cut *ollo%ing t+e contour

1; 9e*ractory protection longitudinal- 1 set 'an(as tarpaulin


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T+e special no le %as prepared in contractor0s s+op# 'losed&end stainless steel is drilled at points, atangle 3; deg to s+ape t+e no le +ead# ue to s+op0s limitations, no ceramic protection is applied around t+e+oles t+at usually e pro(ided *or rein*orcement purpose# Hand grip at 5; cm long, *or ease o* operator maneu(er, is prepared separately *rom t+e no le# T+is is to sa*e material usage as only t+e no le +ead %illdamage during t+e lasting process# Simple sketc+ is as *ollo%!

9e?uired material is per t+e *ollo%ing ta le!

C+ole sand last %orks a o(e is completed %it+in 1 days time *rame +ours s+i*t&%orks-#

Radiant Section (Combustion Chamber) Coating T+e *irst e.periment %as conducted in t+e turn around /e ruary ;;5, %+ic+ is purposed to o ser(e

coating sta ility in t+e actual re*ormer en(ironment and taking some in*ormation related to e.pected per*ormance impro(ement# Eig+t coating samples %ere applied around < urners at di**erent locations, co(eringarea appro.imately ;#> m per samples# 'onsiderations *or t+ese sample locations are as *ollo%!1# Docations s+all e e.posed to e.treme operation en(ironment inside t+e *urnace c+am er, in order to identi*ysta ility under +ig+ temperature and (elocity#

# Docations s+all e near o* peeping +ole, *or easiness (isual o ser(ation#3# Docations s+all represent o(erall re*ormer0s %all#

# Docated in t+e lo%er ro% o* t+e urners *or easier installation#'oating t+ickness %as applied di**erently, ranging *rom 1 mm to (ery t+ick, to con*irm t+eoretical

co(erage area 3 kg@m using our c+osen *urnace coating /urnascote o(itJ# T+is material is c+aracteri ed y

(ery +ig+ content o* 8irconia and imparts +ig+ resistance to aggressi(e attacking en(ironments typicallyencountered at +ig+ temperature# 'omplete c+emical compositions are as *ollo%! 8irconium > #=7A, 4luminum1#>3A, 'alcium 1#37A, Fagnesium ;#3 A, Silicon 3 #;>A, Titanium ;# 5A, Boron 1#1A and /luorine ;# 5A#

Fi.ture o* *urnascote in %ater 5 kg o* *urnascote in 3# liters %ater- %as applied %it+ a paint rus+#9e?uired ?uantity is a out 3 kg@m in order to ac+ie(e t+ickness 1 mm ar itrary-# It +as a good ad+esionto t+e re*ractory %all# T+en, t+e sample %as aerated se(eral days *or natural drying, in order to a(oid t+ermals+ock and rapid e(aporation upon urner ignition#

4*ter = mont+s operation, %e +a(e t+e opportunity to do (isual o ser(ation again inside t+e Turn4round# /ollo%ing is t+e result!1# Gisually, t+e samples %ere strongly ad+ering to t+e casta le sur*ace# 6nly minor deterioration occurred insample one# /urt+er in(estigation s+o%ed t+at t+e sample is t+icker compare to t+e ot+ers# T+ere*ore, it isconcluded t+at e.cessi(e t+ickness is not pre*era le#

# 'oated sur*ace %as smoot+er t+an non&coated, %+ic+ is in line %it+ o ser(ation during operation# T+is sur*ace

is s+iner, %+ic+ indicates etter re*lections#/rom t+e *indings, it is concluded t+at t+e coating is applica le *or re*ormer0s *urnace and also a le to pre(ent any releasing dust material or erosion# /urt+er resuming t+is good result, application to ot+er sections ist+en to e conducted gradually# Here elo% is record o* implementation!

Total ar#a to b# coat#d 2'343 m (

T4 o(em er ;;5 =#1> m4ctual co(erage area t+in- #57 ; kg@mor ;#3 7=>#;; m

4ctual co(erage area t+in- #1>35 kg@mor ;# > m @kg

No /at#rial 1ty. )p#ci*ications

1 2arnet ; Ton

Si e! ;@ ; mes+#'omposition!4lmandine! =7 =


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!oating progr#ss o5#rall 67.84 9

R$) +T) AND !ON!+ )ION)'leaning %orks using met+od and e?uipment presented +erein is pro(en to e success*ul# 9ed *ouling

can e remo(ed e(en to t+e +ardest position inside t+e tu e anks# Belo% is result o* cleaning on are tu es!

4nd elo% is picture on *inned tu e!

'leaned tu e color is ack to its lack&acti(e state# Heat duty impro(ement %as o ser(ed as *ollo%!

D#scription nit*or# A*t#r D#lta

,A- ,&- ,& : A-E&; ;1 2cal@+ 1 # 1 1># 5 # 15#7 #>< ;# 13#3< &;# > &1#=1AE&; ; ' 2cal@+ ;#< ;# 7#5>A

6(erall a sor ed +eat 2cal@+ 5


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Per*ormance impro(ement is measured *rom +ig+er temperature at t+e coated sur*ace due to re*lectingmore +eat and lo%er temperature at outer %all o* re*ormer# Belo% is ta ulated result!

No. )ampl# Typ# Inn#r ;all' ! Out#r >#1;

on 'oated 1; >#71 >=#=1

Di**#r#ntial 76.7= >.=2

Summing up t+e *indings *rom our e.perience are elo%!1# /ouling in t+e con(ection section o* primary re*ormer +ad caused operation di**iculty and *orcing to sacri*ice

plant e**iciency in order to maintain some operation parameters %it+in considera le sa*e range# T+e *oulingmaterial is suspected comes *rom t+e re*ractory y erosion@e(aporation#

# Pro(ided cleaning met+od and tools is pro(en to e success*ul remo(ing t+e *ouling#3# Special coating application in t+e re*ractory sur*ace is pro(ed to e sta le and producing e.pected result#

# T+e %orks presented +erein +ad impro(ed con(ection section0s +eat a sorption y #51A#

T"$

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Makalah Convection Section Cleaning 4.doc