RLD C ∵ 冒围 C""① 巳① Gˇ Vo LVaJ E11 NU M BER7 sEPTEItl B E R 1980 ˉˇ `∷ ● ● k· ∷ 0= Ⅱ i· ∷ TⅡ E Ⅱ EW p△ CⅡ IⅡ C C● Ⅱ CEpT The ll/δ "ers Reverse Hood sh门 nk u’/rapped Package(Us-and other patents)-t冖 is un tis stab丨 e ˇ V thout any other support easy to hand}e,VVeather proof and Is spaoe sav丨 ng The ReVerse Hood proVide$proteCuon in seVere cond tions dur ng trans- port and transfer of loads, M0ELLERs(∪ κ )L|M丨 TED,i4ˇV00DF0RD R0AD BRAMHALL,sT0CKPORt,CHEsHlRE‘ sK71JJ tELEPH0NE∶ o61440○ 4○ 0-TELE× ∶ 668662 AN Ass00|ATE0FM0ELLERs,BECκ ∪M,ˇVEs丁 GERMANY
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RLDC ∵冒围C""① 巳①Gˇ
Vo LVaJ E11 NU M BER7
sEPTEItl B E R 1980
ˉ ˇ
`∷● ●k·
∷0= Ⅱi·
∷
TⅡE ⅡEWp△CⅡIⅡCC●ⅡCEpTThe ll/δ
"ers Reverse Hood sh门nk
u’/rapped Package(Us-and otherpatents)-t冖 is un tis stab丨 eV̌ thout any other support easyto hand}e,VVeather proof andIs spaoe sav丨 ng The ReVerseHood proVide$proteCuon inseVere cond tions dur ng trans-port and transfer of loads,
For cc1△ cnt has nCcessi1a1ed the design of rotary k"ns
of lafgc capacitiGs As Iargc diamctcr kilns becolη e
less a、 a lab1c.methods to incrcase the k"n· s speCiFlC
output have becotη e the centrc of research
In the Federal Republic of Cermany,however,the
original idea for adopti]lg the secondary hringpri∶ lcipIc、 vasto in1roduce a fue1-beariIlg r[1、v lη ateriaⅡ
io, oil-sha1e, 、vhich contai]ls a high Ilea1ing value,
scparatCly into thc s1|spcnsion l)rchGator for econˉ
onlical utjjzation the calcinatton of thc matcria1
、vith the burn"lg Ofr of its c。 mbustible lllatter in a
co1η bustion chamber at the bottom ofthe pΓ eheatcr,
resul1sin the po、sibi1i1y of reducillg1he k"n volun e
This spccia1apphcation Ilas1ed 1o ftIr1her kno、 Ⅴledge
and d1)vc1opm1)nts in prccalcining tcchniq1Ies
了hCrC sccms to bC a did℃ rcnt approaCh ill 111e
appIicatton concCpt of preCalc"ling processes bCt-
、veen Japan and thc FRG In Japan, the greatestpos“ ble po]“ on(50-70%)。 f the ltd′ burned in
1he prehea1er in order 1o a1tain the 11ighest speci】 ,c
k"n ou1put ln1hc FRG howcvcr,lCss attomp1isluadc to consumC motC f1cl at tbe prChGatGr, than
maintaining80-90:‘ calc lati。 n for ease of opefa-tioll It has been 1ea"zed that a high degree Of pre-
heater burn"lg may cause cloggiIlg in 1he Io、 ver
cyclone st∶ lge as(1res u11of the high1empera1ure rise
oF1he ra、 v]nea1,and iIlcrcasCd、Vastc gas losscs
RCsGarCh and 1)racticc made on botb sides. ho、 Ⅴ-
CvCr, havC 1)rovcd one con】 mon faCt——that the pre-
calcin lg prOcess is the tη ost suCCessful technique in
Ⅱηprov"lg the peΓ fc Γ1η ance of suspension preheater
kilIl systems
VaⅡous ρrCCaICining systems
l sf匀‘`c″
('愆〃c扌 )
J。inuy deve opcd by Ishikaw1nla~HaⅡ ma HcavyIndust1es Co Ltd and Ch chibu Cclnent CO LtdoF Japan,SF is the abbrevia1ion of Suspension F1ash
Calciller The nrs1 sF 、vas apphCd in a 100O tpdsuspen“ on pⅡ hcatcr knn(39m dia× 5137m)inCllichibu s No j works,and was comnlissioned inNovember j971 Eight months later,aFtef numcrousmodi6catiOns and improvemcnts, the system was
W0RLD C:MENt T「 C"`oLOGY s厂 PlrM8厂 R 1980
丬
顿
咖
咖
岫
咖
^●
一̀"‘
● ̌^●
一●●一●●
●一一̌
′k奶 c2 乃'″
〃″ 攵而`t呷
巛″汩、
◆ ‘灬◇ ^胂 ’|官
^1
based on 0noda’ s expericncc in thc hIη e-burning
pr。 cess in the car1y years,in co刂 uncu。 nw"h suspension preheater k"ns RsP is the abbIevia1ion of
Reinforced suspension Prehea1er The nrs1 RsPp"ot Operation 、vas eλ perimented in 0noda sTaha〗 a w。 rks,w th a18m dia × 28m klln,pro-ducing240tpd,in 1972 In 1974 thC nrst RsP kilnsys1em、 Vith a capacjty of2700tpd、 vas colη missionedjn 0noda Cemcnrs ofunat。 works The secondRsP knn(37m dia ×58m)was comm sg。 ned hl
Indoce1η enrs Cibin。 ng works hl lndonesia, with a
capacity or165O tpd,h11976
Raw meal descending仃 O lll 1he s1age-2 cyclonc is
6rst heated hl thc swirl ca1cher,in which C0⒉ is
driven of rapidly,and then dGscGndsinto the mix"lg
Carry thC ra、 v mcalinto the stage-1cyclone,w hcre the
st spcnded ra、Ⅴ mealis calc"led.tnd separated,be亿 re
cntering the rotary k"n
'△〃`cJ s厂
s ,`″ ″
助 〃`〃
亻 ′sF‘J、`‘
″`
proved to be capable of producing200O tpd Basedon thc experienCC gaillcd in this operation, Chichibu
Cement convertCd one of i1s 、vct proCess knns(55m dia× IOO m),lt dle Kumagaya works hl1oan sF systcm in 1973, which aⅡ er commissioningproⅤed to be capable of producing7800tpd Ihis is
so far one of the Iafgest sF kj1ns in thG、 vor1d,usinga twinˉ to、ver suspcnsi。 n preheatef the kiln llas aspeci6c hcat consunlption of744kca∫ kg-c"nker
PreCa1Ci1】 ing is perfOrmed in a F1ash FurnaCewhich consists of a vortex duct at the bot1olη of a
rcaCtion Chamber, o1】 、VhiC11 1hree burnGrs are
insta⒒cd Ra、v mca1 desCends fro1△ the Centre in1ct
of the reaction Chamber 、vhcrc it mGcts the com-busting mixture of cooler air al1d kj n exit gascs
asCending仃 olη thc Ⅴ°rteX duCt in a stfong turbulent
n°w Thein【 lmate mixing and heat1ransFer betwecngases and ra、 Ⅴ mea1produces11igh ca1cina1ion be、 re
the ra、v mca1enters the knn
2R驴 sⅡ s泗99(ng〃`召
匆Tho sy“cm wasjo血⒒y dcvclopcd by0noda CementCo and Kawasaki Heavy Industries Ltd,of Japan. 卩仔W'j l’∫C9V″ ″
3 1,fFC s s`臼 ″Jlg″厂e∮)
Ano1hcr jolnt deVclopment th灬 ume by Mnsub、 h
HeaVy Industoes Ltd, and Mitsubishi Minitlg andCGmcnt Co Ltd OfJapan `Ι FC is1he abbreviatlon
of Mitsubishi F1uidized Ca1ciner ExPerinlen1s beganjn 1963 and 1he paten1 For thc MFC dcsign 、Ⅴas
obtained in 1968 In 1971. 卜1itsubishi Mining andCemen1adoptcd MFC in jts HigasInltani works,to a43m dia × 65m Dopol preheater k"n, 、vhich
easi1y achicved 2000tpd 、vi1h a 15ˉ month uninterˉ
ruptCd operation after Conlmissioning
The calc ning of raw mea1 is pcrforlned in aseparately heated nuid bcd rcactor insta"cd undcrthc
stage-2 cyClone R孙Ⅴ mcal is introduccd jnto the
reactOr and is nuidized by thc aeratio l air supplied
仃om ab1owcr whiCh draws hot a r flOm the c"nkercoo1er Thc nuidizcd 「a、v mea1 is ca1cined by 1he
heat gcnerated 9om burners nlOunted t1round 1hc
、Voκ LD C£ MENt t〔 C"`oI OCΥ s(PT[MB「 R1980
蕊甜田艋投品 :ˉ~
358
n“″'6K” ,sjr″ ‘
Icactor be1o、v ",e nuidized bed surn1ce Calci11od
ra、V mCalis carried by thc combus1ion gascs into thc
s1agCˉ l Cyclone 、Ⅴhcre i1 is separatCd and enters the
kiln
4Ks'助 srf″t(ΠglIrc6)
KsV is the abbrcviation Of Ka、vasaki Spouted Bedand Vor1ex Chambcr,deⅤ eIoped by Ka、 vasaki HeaⅤ y
Industrios Ltd of Japan The l,rs1KsV was adopted
by Tokuyama soda Co L1d in 1973 for one of itscxisti11g suspcnsion Preheatcr kilns The convcrted
knn system 、Vas ProVCd to be capable Of producing3800tpd The1argcst KsV plesently in Opcration is
a‘ 2m dia× lO5mk"n system of Ube KOsan CoL1d,Japan It、 vas comInissioned in Apri1 1975, and
has sincc been operating a1an ou1p111oF85001pd
Consisting of fr ur zOncs,thC KsV furnace aCCepts
fa、v meal frOln 1wo stagC-2Cycl。 nes at t、Ⅴo separa1e
p。 siti° ns∶ onc at thC secondary air inIct duct, and
the o1her on top of the vortex chamber K"n C疝 t
gases are introduced9om the bottom ofthe fufnacG
and arc tfansformed into ∶1 ‘spouted Currenr "l the
spoutcd bed Mean、vhi1e 1he seCondary air being
dr孙vn iom the C1inkcr coo1Gr enters thC furnacetangentia"y1o凡 rm a ⅤorteX ii1the vortex Chanlber,
、vhere the spoutcd curlent and vortex ate miXed and
asCend into thc auⅩ iliary spout bed enroute to thC
mixing chamber B1】 rncrs plaCed at diJIerent posi-
tions spray ftlel into the Ⅴor1eλ chamber and the heat
produced is adsorbcd progrcssive1y by tbe highly
concentrated ra、 v mca⒈ and dccarbona1ion occursrapidly Ca1cincd ra、 v n△eal js separatCd from thc
kihl gascs in the stagc-1 cycl° ne^ before cntcring thc
k"n
5 D Jl sys`召″(∏gⅠ
``c7)A systcm joinuy deve1。 ped by Nihon Cclncnt CoLtd and Kobe stcc1Ltd ofJapan DD isthe11bbre、 △a-
1ion of Dua1Combustion and Dcni1ration FurnaceThe nr“ DD systcn△ Was adopted by Njhon Cementin19"in证s KamⅡ so works.ftr a3600tpd← “ m
W0i(LD CEMENT IECHN0L0GY s:V△ LMB△ 【 1980
da × 767m)k"n systGm,afler ga""ng opeIa"nLexperienCe wi1ha500tpd l)D knn at N"l。 n cenlcnrs
saeki 、Ⅴorks The Ka1η"so knn eventu〔
1lly reachcd
an o1tput of 3960tpd at a hea1 consun11Dtion of735kcaΙ∷kgˉ chnker
Calciling is perftirmed in a DD FurnaCC plaCedaboⅤ e the kiln in1et housing Ki1n cxit gascs cnter
diIect1y i]l1o thc f1rnacc 仃om the botto1η , 、VhiIc
prehea1cd combustion ail enters thc Ftlrnace订 om1hechnker coolcf via an ind11ccd air duct Ra、v mea1CntCrs the ftlrnacc仔om the side of1he furnacC just
aboⅤ e the burners Fue1 and gas arc thoro1ghlymixed in the aⅡer-burning zonC in thG uppGt part。 f
the fufnaCc,、vhere complCtC combustion is achicved
Ct11Cilled ra、 v mCal is brought "lt。 thc stage-1
cyc1onc、 vith hot gases and is separated仃 om the gas
strCam
6 '‘sP,cc″ c llf严 (F· gl Fc8)
The F L smidth Prcca1Cining sys1e]u has two indcˉ
Πg〃″ 8 ’iEs ●″″
′t″ c7DD”"″
″
pcndent suspCnsion prebcatCr IiI1cs∶ onG ConnCCtCdto thc k"n, and the odler conneCted to thc precaⅡc“er Λpproximate y40%ofthe law mea is fed tothe k"np1ehe扯 eΓ
"le,and the remain ng60%灬fed
to the plecalcillcr line Prehea1itlg or r11、v meal is
efIected by the ki1n exi1ga、 es, and preCalCiner con1ˉ
bus1ion gases.respeCtive1y.in the prehcater CyC1on1)s
Prehea1cd ra、 v mcal is i11troduCCd into thc prcca1ˉ
cincr,whGrG it is ca1cincd to90;。 by burncrs mounted
on thc lo、 Ⅴer1)art of thc precaIci11er cha1η bCf, and is
brOught 、Ⅴith the hot gas strean△ Ⅱlto the stage-1
cyclone^ 、vhere the calciIled ra、Ⅴ meal is separated
仃om the gases and entersthe knn In the FLS systenl,
60%Ofthe i】 el^burned in the precalciner.and tlle
lema nhlg40%burned in1he kiln A400Otpd FLSsysⅡm← 75m dia ×75m)was commlssloned jn1977a1Aso Ccmcnt Co s Iagawa works With a heatConsun△ ption of740kcal∷ kgˇ c"nkcr
Il tbjs design, the distribution of co1η bustion air
betwecn the k"n and precalciner is eas1y controlled
because ofthe t、 vo independent pIehea1er lilles TllG
hot[1ir fronl1he chnker coo1er being the onIy con1-
`e助Pol· sllls AG of`Vest G∝ many has developed twok而 ds Of precalc n ng systems PREP0L AT(ai卜through)and PREP0L As(Air separate) The ATsystem is part cu1ar1y no1e、 vor1hy as i1 is tbc nrst
prcCa1Cining systenl 1o dispense with thc tcrtiary ajr
duc1 connected bet、 vecn the Clinkcr coOler and thc
preheatGr
In thc A】 SystGm,the Cnt fe co1η bustiOn air no、 v`
throug11thc k"n, and calc"ling is performed iIl the
plecalcjner plaCed bet、 veen thc kiln in1e1 and 1Ilc
stageˉ 1 cyc1one Ra、Ⅴ mea1 is illtrod1ICed Ⅱom 1hcstageˉ2 vOrtex Vesse1 in1o 111e preCalCincr and is
calci]led by hcat‘∶∶en era1cd by thc burnGrs mounted()ll 1he10、 vcr part of thc prcca【 cincr duct Fof thcsamc dialuctcr, thC AT System llas a higher gas
Π甲i· , ’’尺「P0∠ 刀7o,v″″
ve|ocity in t11ek"n because of the 1argcf gas VoluluC
Conta""ng excess aⅡ ofabout12%Oxygcn HowGvcr,Opcrat ng cxpcriences have sho、 vn that this highGl
gas ve1oc ty does nOt aiIect the ki1n pefformance in
slη aller k"ns of11p to2000tpd For larger capac ties,
however,1he AT Sys1em requ沁 es about20%k1· ger
kih1diamctcrs Thc AT systcm can Ci1hcr be cquip-pcd 、Ⅴith a grate cooICr or a planctary c。 olCr Tlle
nrst PREPOL ΛT systcm was Ciments △aflrgc′ s
46nl dia / 75m kiIn cOn△missiOncd i1 1973 、vjth
a capacity of3000tpd the1algest AT system cuf-弋ntly in operadon is a4700tpd knn(52m da ×80m)a1Cementa AB s shte wOrksin Swedcn EaΓ ly
in1978a300O1pd AT sys1em(46m dia ※70m)Was suCCCssΓ ully commis“ oned a1 Aslan Ce∶ ηent
ups A1kahes and su1ph ur,being partia11y vo1at"ized
in thc burning zone, 、Ⅴi11 eventuauy lcave 1he knn
in thG chnkcr Ch1orides, 11aⅤ ing becn vo1atilized in
the burning zonG and rGCondensed in thc prcheater,continuc to be Conccntra1ed Thcse obJcctionab1eCompound8 fortη an intCrnal recircu1ati。 n cyclC inthc k"n system,assho、 vn in FigurG13
Furthermore, if thc ra、 v ∫naterial contains bituˉ
minous substances, such as kcrogcns, Coa1ˉ shale,
oil^sI1a1G and such 1ike, Overheating occ1】 rs in thc
uppCr stages of1he prehea1er
The Follo、ving problcms arc caused by an thcse111desirab1e chemica1s∶
(a) Poor c"nker quality duc to excessive quantity or
∶t1ka1i
(b) B1"1d-ups and cloggings caused by GxcessiⅤ e
quant ties oFalkali.ca1ounn sulphates or Ch1orides
i∶l thelo、vcr stages ofthe prcheater
C)0vcfheating in the upper stages of thG preheaterby the combustion of bi1ulη inous ra、Ⅴ ma1eria1s
To oⅤ erCo1△ e1hese problems,a bypass system must
bc usod ‘o diΥcrt par1 。f1bc knn gascs, befcrc thcy
a‘4
enter thc preheater^ into a separate 、vastc gas-handhng system c° nsisting of an air qucnch cham-bGr, coo1ing air fan, dust co11ec1or and exhaust fan
I·lgurC14sho、Ⅴs a typica1bypass arrangement lvlth
a suspCnsion Preheater equippcd、vith a precalciner
T° avoid f。 rnlatiOn of build-ups caused by thevapourized compounds and alkaΙ i-ladcn dust, thebypass gascs m1s1 be imInediately quenChed bycoo1ing air upon 1Gaving the preheater duct Ihegases, being co° Icd down f1oI】 1100°C to abou1450·C, w"l i1rther bc c。 oled by water spray toabou1 28O·C, befole cntCring the dust co"cct° r
thc percentage of kiln gas bypass quant汪 y s
determinGd with regard to the approp五 a1e1o、vefing
of the conccntrations of chloridcs, sulphates anda1kalies, both in the prcheater system, and in 1he
outg° ing clinker.in such a 分act on that thc prob-1ems wnl be rcduccd to an unharmftl1cve
1fthc bypass is on1y intended For thc reduction of
o旬 ec6° nable chcmicaIs to c1imin,lte p1ehcatcr c o⒏
ging prob1ems,° nly3t。 5%bypass may su质 ce
Thc cqulpment costs孙 r such instal1ations ale not
very CXpenslve
In North A1△ erica, 、Ⅴhere cement users demandthat thc aⅡ o、vab1e a1kah cOntent in cetnent be less
than O6%total a1ka1ies eλ pressed as Na20讠 q uiv-
a1ent, 1η uch larger bypass systems_ˉ in the rangc °fI孓JO%— haⅡ to bt· “∞ siⅡ e u1。 b,lla、 wstemhand1es lligh tclη pefaturC gasCs in1arge volumes,thc
inⅤ Gstment Costs fOr thc instanati。 n arc Considerably
higher This wlll be assoCiated ,itb substantia【 llea1
and dust losscs practica1operation experienCcs have
reveaIed that for evcry l% of ki1n gases bypasscd,
the hcat losses 、Ⅴould bc 5-7 kca1∫ kg clinker, andthc dustloss would bc0j5~020%
When a pⅡ calc1ner js cqull,ped t0the pleheater,
abou1on1y50%°f thC gases passing dlrough thepreheater comc △om the kiIn, thcrCft,re, a m1】 Chsmaller bypass is required to attain the same errec1
、~0RLD CtMtNt t[C"N0L0GY sr1T△ “ ⒔⒈ 1 1,80
Fi甘△″c`j``‘ 〃伐″″〃竿("氵
"“c″ "″”′0· %j丿
`″
、̀
EXpGr"η ents haVe proⅤCd that w th a inrCCalCiner
burning 、vi111 |、 es11 conlbustion air rccoⅤ cred frotη
the clinkcr coolcr,it is plactica"y possible to bypass
100%or1hc kdn gases(F guR15)Th。 。 paΓucularIy usCfuI for p ant、 wnh dimcult raw material、 oI
ftle1cOnditions
UtiIiza(ion ofIo{gIadc ilIC1s
Rising cnergy cos1s havc pronlpted cenlcnt n1an1-
factul e1s tO lOok for altGrn.ltiⅤ e、 tO heavy fucl od
Coa. 、vhich had bGcn almost exc111siⅤ G1y 1scd fOr
nting the rotary k"n l the ear1y days, has been
nlakilg a Conac-back il the conlont h9d11stry
Althougln coaI nf t)g lla、 bcCn ado atcd by suspension
prehcatcr kiIns n)ral。 ng 1imo tl)c in tial design or
1hc precalcin"lg sy、 tCnl 、vas based On the use or oi
as fuel Consequcn1】 y many eⅩ pertη ents have bCCn
lllade ill Γecen( yCars 、vith tegatd to the app1ication
of pulⅤ erizcd coal fof conlbust o l in 1he prCCa|Cinef
ExperienCC has ptOved tl11t buInillL· high gradecoa⒈ or naturaI gas, il a llreca1cillcr docs 11ot p。 se
1Oo n1uCh Of a probleln B111 thc usc oΓ lo、V gtade
coa1of b tunlin1)us ra、 Ⅴ llla1Cfials such as O s̄hale
Coal-shale,and 1he1iko ca"s for special llandl ng1uld
trcattη ent tlle il1】 portant aspects "l buΓ nilg 、uCh
fuels "l t11e preca1Cining systenls are the cOn1ro1 of
f· ed quan1i1y 1hrough tle bufneI、 t1nd 111e Con1rol
Of fue1quahty1crGrf l、 g to its llonlogenei1y in ordcr
to mail、1ain a cOn、 tant he111 illpu1 h)1o thc prGcal-
cillcr tbcrcby ensur lg s1eady ki n opcra|ion
Hor so"d fue1、 、uch as thOscjustlη Cnt onCd feed-
ilg can be eI讠 oc1cd by lllcains of precisiOn 、veighing
de、 ices H()wevcr 1o aCConlplish constant nOW or
heat i】 l1o 111C prGcalchncf, the fuel ha、 to be 、ven
blendcd dricd and 狗nely pulvefized, be|、 re bcill(∶:
doscd into thc l)i ecalc"leΓ such go[11s Can bC achicⅤ cd
wi1h thc use of st∶ tckerˉ rec1[1mcr equ ηηcnt, al,d a