Hastelloy G-30 nyob rau hauv Phosphoric Acid Evaporators: Kub Exchanger Tube Performance Data

Vim li cas Hastelloy G-30 Specification rau Phosphoric Acid Evaporator Tubes?

G-30's chemistry - siab chromium nrog nruab nrab molybdenum thiab tooj liab ntxiv - tau txhob txwm tsim los tswj cov kev sib xyaw tshwj xeeb ntawm cov kab mob uas pom nyob rau hauv cov txheej txheem ntub dej phosphoric acid, thiab Haynes International npe P2O5 evaporator raj ua ib qho ntawm ob daim ntawv thov.

Tau qhov twg los: Haynes International nominal muaj pes tsawg leeg cov ntaub ntawv, HASTELLOY G-30 alloy.

Cov ntsiab lus chromium siab muab G-30 muaj zog tiv thaiv rau oxidizing tus yam ntxwv ntawm ntub- txheej txheem acid thiab nitric acid thiab nitric-acid sib tov, thaum nws cov molybdenum thiab tooj liab ntxiv muab nws nruab nrab tsis kam txo cov kua qaub xws li hydrochloric thiab sulfuric - ob qho tib si uas yog tam sim no ua lag luam nyob rau hauv impurities. Haynes International kuj tseem sau tseg tias G-30 tsis tshua muaj kev cuam tshuam rau cov tshuaj chloride-induced stress-corrosion cracking dua li cov austenitic stainless hlau nws nquag hloov hauv cov kev pabcuam no, uas tseem ceeb rau cov khoom siv hluav taws xob uas pom rov qab thermal cycling thaum lub sij hawm evaporator pib thiab kaw.

Dab tsi ua rau ntub dej -Cov txheej txheem Phosphoric Acid thiaj li ua rau evaporator Tubing?

Kev ntub dej - txheej txheem phosphoric acid yog corrosive feem ntau vim yog yaj hauv nws, tsis yog phosphoric acid nws tus kheej: unreacted sulfuric acid, nws yog xim hlau ions, fluoride ions, chloride ions, thiab tshem tawm particulates xws li silica tag nrho cov caij nrog rau cov P2O5, thiab ntawm cov tshuaj chloride txiav txim siab dormancy ntawm cov tshuaj no. cev life.

"Kev ntub dej- txheej txheem" ​​phosphoric acid yog tsim los ntawm reacting phosphate pob zeb nrog sulfuric acid, thiab raws li tsim nws muaj tsuas yog li 30% P2O5 vim hais tias ntawm lub ntim loj ntawm cov dej yaug xav tau los cais nws ntawm calcium sulfate byproduct. Fluoride ions zoo li tsim cov complexes ruaj khov nrog cov hlau ions hauv kev daws teeb meem thiab yog li tsis tshua muaj siab rau cov ntaub ntawv raj dua li chloride ions, uas cuam tshuam rau cov tshuaj electrochemical ntawm cov kua qaub thiab cov hlau. Qhov no yog vim li cas alloy xaiv rau evaporator tubing yog tsav ntau dua los ntawm chloride-pitting thiab crevice- corrosion resistance dua los ntawm cov kua qaub nominal phosphoric acid zog ib leeg.

Thaum lub sij hawm evaporation txheej txheem, P2O5 concentration yog feem ntau tsa los ntawm kwv yees li 30% mus txog 54% nyob rau hauv ib tug series ntawm evaporator theem. Cov concentration siab dua ib leeg yuav qhia tias muaj kev sib kis ntau dua, tab sis Haynes International sau tseg tias cov txiaj ntsig no yog ib feem cuam tshuam vim tias qib impurity - suav nrog cov tshuaj chlorides uas tseem ceeb tshaj - yuav poob vim cov kua qaub ntau dua.

G-30 Ua li cas hauv Kev ntub dej tiag tiag-Cov txheej txheem Acid, Tsis yog Reagent-Qib Acid?

Haynes International thim rov qab nws cov reagent - qib cov ntaub ntawv kuaj nrog teb - cov neeg sawv cev kev sim ua nyob rau hauv cov dej tiag tiag - txheej txheem kua qaub muab los ntawm Florida phosphate tsim tawm ntawm peb qhov kev tsim tawm tiag tiag (36%, 48%, thiab 54% P2O5) thiab 121℃(250℃stainless hlau sib tw),{ ntau ze rau qhov kev khiav hauj lwm evaporator dua li qhov ntsuas reagent-qib beaker.

Qhov kev sib txawv no tseem ceeb rau ib tus neeg hais txog cov khoom siv tube los ntawm cov ntaub ntawv: reagent- qib corrosion tables (siv thoob plaws hauv tsab xov xwm no rau lawv qhov tseeb thiab rov ua dua) cais cov nyhuv ntawm acid concentration thiab kub ib leeg, thaum ntub tiag tiag -cov txheej txheem acid ntxiv cov fluoride, chloride, sulfate, thiab particulate load tham saum toj no. Haynes International qhov kev txiav txim siab los khiav qhov kev mob siab tiag tiag -kev sib piv ntawm cov kua qaub ntawm kev tsim khoom- cov ntsiab lus tseem ceeb yog ib qho tseem ceeb ntawm kev mob siab rau, thiab nws yog vim li cas G-30 nqa cov ntaub ntawv tseeb, cov ntaub ntawv pov thawj hauv daim ntawv thov no es tsis yog cov theoretical nkaus xwb.

Kev ywj pheej teb thiab tus tsav-cov ntaub ntawv cog lus qhia hauv phosphoric- cov txheej txheem cov kua qaub ntxiv ntxiv, ntev dua - cov ntaub ntawv taw qhia rau Hastelloy G alloy tsev neeg: hauv phosphate pob zeb zom zom, Hastelloy G alloy impeller tau sau tus nqi corrosion ntawm 6.57 mils per txhua xyoo. nyob rau hauv ib txheej ntawm digester tej yam kev mob, thiab 11.71 mpy tawm tsam 15.77 mpy rau 625 nyob rau hauv ib tug ntau dua - oxidation- tej zaum yuav mob. Cov duab no piav qhia txog G-tsev neeg alloy es tsis yog G-30 tshwj xeeb, tab sis lawv corroborate tib lub ntsiab lus xaus Haynes 'tus kheej cov ntaub ntawv qhia: G-tsev neeg nickel-chromium-hlau alloys tuav zoo tiv thaiv 625 nyob rau hauv tiag tiag phosphoric acid, tsis yog nyob rau hauv ib puag ncig ntawm phosphoric acid.

G-30's Corrosion Rate Hloov li cas Acid Concentration nce thaum evaporation?

G-30 tus nqi corrosion nyob rau hauv boiling phosphoric acid nce tsis tu ncua los ntawm 50% mus rau 85% concentration, tab sis nyob twj ywm qis thiab tswj tau (0.01-0.84 mm / y) nyob rau hauv tag nrho cov ntau yam ib tug evaporator tsheb ciav hlau yuav pom, nrog rau qhov kwv yees li ntawm 54% P2O5 endpoint raws li coj mus muag concentration.

Tau qhov twg los: Haynes International reagent - qib phosphoric acid corrosion rooj, HASTELLOY G-30 alloy cov ntaub ntawv ntawv.

Txij li feem ntau kev lag luam ntub dej - cov txheej txheem tsheb ciav hlau tsom qhov kawg ntawm 54% P2O5, cov neeg tsim cov raj tuaj yeem cia siab tias G-30's reagent- qib corrosion tus nqi los zaum hauv 0.1-0.2 mm / y ntau yam ntawm qhov kawg ntawm qhov kawg - zoo nyob rau hauv ib qho yooj yim corrosion pub rau lub neej ntau ntxiv, ua ntej kev pheej hmoo ntawm cov tub ntxhais kawm. chlorides tau tham hauv qab no.

G-30 Piv rau 316L, 254SMO, thiab Alloy 625 li cas hauv Evaporator-Relvant Acids?

Haynes International tus kheej qhov chaw sib piv qhov chaw G-30 ua ntej ntawm 316L thiab 254SMO stainless hlau nyob rau hauv ob qho tib si hydrochloric thiab sulfuric acid, thiab ua ntej ntawm Alloy 625 tshwj xeeb hauv hydrochloric acid - tab sis Haynes hais ncaj qha tias G-30's 0.1 mm / y kab zaum me ntsis siab dua 625 acid sulfuric acid. qhov twg sulfuric acid paug yog qhov kev txhawj xeeb tseem ceeb.

Qhov no yog ib qho tseem ceeb, cov ntaub ntawv ncaj ncees rau kev txiav txim siab tshwj xeeb: G-30 tsis yog universally ua ntej ntawm txhua qhov sib tw alloy hauv txhua cov kua qaub uas evaporator yuav pom. Qhov twg cov impurity tseem ceeb yog sulfuric acid nqa los ntawm pob zeb- kauj ruam digestion, Alloy 625 (los yog siab dua -chromium HASTELLOY G-35, nyob rau hauv ib tsab xov xwm nyob rau hauv no series) tej zaum yuav muab ib tug me me cov paj ntaub ntxiv. Qhov twg cov kua qaub nyob ze rau cov dej ntshiab-txheej txheem chemistry nrog nws cov yam ntxwv chloride load, G-30 qhov sib npaug ntawm chromium, molybdenum, thiab tooj liab muab nws qhov txiaj ntsig zoo dua ob qho tib si stainless hlau thiab 625 hauv hydrochloric acid tshwj xeeb.

G-30's Resistance to Under-Deposit Pitting thiab Crevice Corrosion yog dab tsi?

Raws li ob txoj kev ntsuas ceev uas siv los simulate chloride-fouled tej yam kev mob - Ntsuab Tuag thiab daj tuag - G-30 thawj zaug qhia pitting ntawm 55℃thiab crevice nres ntawm 45℃(Green tuag) los yog 25℃(daj tuag), uas yog raws nraim cov tsis ua hauj lwm hom evaporator yog feem ntau scaled evaporator tube. cev nto.

Tau qhov twg los: Haynes International pitting thiab crevice corrosion cov ntaub ntawv (24-teev xeem), HASTELLOY G-30 alloy cov ntaub ntawv.

Qhov no yog cov ntaub ntawv tseem ceeb tshaj plaws uas ua haujlwm tau teeb tsa hauv kab lus no. Bulk acid kuj, raws li qhia nyob rau hauv cov ntsiab lus saum toj no, piav qhia txog dab tsi tshwm sim rau ib tug huv tube nto raug uniformly ntws acid. Cov evaporator tiag tiag khaws cov nplai, calcium sulfate deposits, thiab stagnant zones ntawm baffles thiab txhawb daim hlau - tej yam kev mob uas concentrates chlorides hauv zos thiab tuaj yeem ua rau pitting lossis crevice nres zoo hauv qab cov kua qaub nominal ua haujlwm kub. G-30's crevice-corrosion pib ntawm 25-45℃yog qhov muaj txiaj ntsig, muaj txiaj ntsig zoo tshaj qhov ntsuas kub ntawm cov evaporator rau ntau tus qauv, tab sis nws kuj tseem qhia txog vim li cas lub sij hawm tu thiab tshuaj xyuas hauv qab cov nyiaj tso tawm tseem ua qauv tsis hais txog kev xaiv cov hlau.

Puas yog G-30 Resistant rau Chloride Stress-Corrosion Cracking hauv Evaporator Service?

Yog - nyob rau hauv tus qauv boiling 45% magnesium chloride test (ASTM G36),G-30tiv thaiv tawg rau 168 teev, kwv yees li xya zaus ntev dua 254SMO thiab 84 zaug ntev dua 316L, thiab ua tau zoo dua ob qhov sib piv npib tsib xee alloys ('28' thiab '31') sim nrog nws.

Tau qhov twg los: Haynes International kev nyuaj siab-cov ntaub ntawv corrosion corrosion (boiling 45% MgCl2, ASTM G36), HASTELLOY G-30 alloy cov ntaub ntawv.

SCC kuj tseem ceeb rau cov evaporator tube bundles vim tias lawv muab ob qho ntawm peb cov khoom xyaw SCC xav tau - cov khoom raug cuam tshuam los ntawm tensile stress (los ntawm thermal cycling, dov rau hauv tubesheet, los yog residual weld stress) raug cov tshuaj chloride -cov kabmob ib puag ncig. G-30's kwv yees li ntawm 168-teev qhov pib hauv qhov kev xeem dhau qhov hnyav dua li cov kev pabcuam ib txwm muab rau cov kws tsim cov raj muaj qhov muaj txiaj ntsig zoo, muaj txiaj ntsig kev nyab xeeb tshaj li cov hlau tsis muaj steel feem ntau suav tias yog cov nqi qis dua.

Vuam cuam tshuam li cas Tube -Seam thiab Tube- mus rau -Tubesheet Corrosion Resistance?

G-30's tag nrho -weld- hlau corrosion kuj nyob ze rau wrought puag hlau nyob rau feem ntau sulfuric thiab hydrochloric acid tej yam kev mob cuam tshuam rau evaporator kev pab cuam, nrog rau kev zam ntawm 90% sulfuric acid, qhov twg ob qho tib si weld hlau thiab wrought base hlau qhia ib tug ntse, matched nce - lub ntsiab lus ntawm ib tug tiag tiag che che muaj ntau dua qaug zog.

Tau qhov twg los: Haynes International tag nrho -weld-hlau (ntau- dhau GMAW cruciform) vs. wrought puag-cov ntaub ntawv hlau corrosion, HASTELLOY G-30 alloy cov ntaub ntawv.

Rau cov evaporator raj bundles fabricated los ntawm welded raj (ASTM B619/B626) los yog xav tau raj - mus rau -tubesheet welds, cov ntaub ntawv no txhawb kev qhia G-30 yam tsis muaj ib daim pam derating rau weld aav nyob rau hauv feem ntau ntawm cov acid tej yam kev mob uas alloy yog npaj rau. Qhov tshwm sim ntawm 90% sulfuric acid yog ib qho kev ceeb toom tias G-30, zoo li G-35, tsis yog qhov kev xaiv zoo yog tias cov nroj tsuag cov sulfuric acid nqa tawm tsis tu ncua mus txog qhov siab ntawm lub raj phab ntsa - qhov xwm txheej uas 625 lossis siab dua-chromium G-35 raj yuav yog qhov kev saib xyuas ntau dua.

G-30's Thermal Conductivity cuam tshuam li cas rau Kev Kub Kub Exchanger Tube Tsim?

G-30's thermal conductivity (kwv yees li 10 W / m·℃ntawm chav tsev kub, nce mus txog 19-21 W / m·℃ntawm 400-600℃) yog qhov zoo hauv qab ntawm tooj liab alloys thiab cov pa roj carbon steel, yog li tshav kub- hloov cheeb tsam thiab cov phab ntsa lub siab ntawm qhov no yuav tsum yog{9} Kev lag luam tawm yog qhov cuam tshuam ntau heev los ntawm cov nyiaj pub dawb heev ntawm G-30 daim ntawv tso cai piv nrog cov phab ntsa tuab uas tsis tshua muaj zog, pheej yig dua alloy yuav xav tau.

Tau qhov twg los: Haynes International cov cuab yeej cuab tam cov ntaub ntawv, HASTELLOY G-30 alloy cov ntaub ntawv.

Qhov no yog kev lag luam engineering tiag tiag -tawm, tsis yog kev lag luam taw tes rau gloss tshaj: npib tsib xee-chromium- cov phab ntsa hlau yuav ua kom sov tsis tshua muaj txiaj ntsig zoo dua li qhov sib piv - tuab tooj liab alloy lossis carbon steel tube, thiab cov khoom siv hluav taws xob thermal tsim (tube suav, ntev, lossis phab ntsa 4} ncaj qha rau tus account. Hauv kev xyaum, evaporator designers offset qhov no los ntawm kev ua kom zoo dua ntawm G-30's corrosion resistance los qhia lub phab ntsa nyias nyias dua li cov pa roj carbon-steel los yog qis dua- alloy tsim yuav xav tau, uas ib feem rov qab cua sov-hloov nplua los ntawm qis conductivity thaum tseem xa ib tug multi-kab phab ntsa kev pab cuam {12 xyoo dhau los. tsawg-resistant khoom yuav xav tau.

Cov Khoom Siv Tube Cov Qauv thiab Cov Qauv Ua Li Cas rau G-30 Evaporator Tubing?

G-30 evaporator tubing yog muaj raws li ob leeg seamless raj nyob rau hauv ASTM / ASME B622 / SB622 thiab welded raj nyob rau hauv ASTM / ASME B619 / B626 thiab SB619 / SB626, yog muab mills-annealed, thiab yuav tsum tau re{1} tom qab{9} raj- dabtsi yog khoov kev ua haujlwm uas ua rau 7% lossis ntau dua txheej txheej elongation kom rov ua kom muaj kev tiv thaiv corrosion.

Tau qhov twg los: Haynes International "Specifications and Codes" table, HASTELLOY G-30 alloy data sheet.

Lub annealing kub rau G-30 yog 1,177℃(2,150℃F) nrog dej quenching qhia, txawm tias ceev cua txias yog ua tau rau cov qauv thinner dua 10 hli (0.375 nyob rau hauv) - ib qeb uas muaj feem ntau evaporator raj - phab ntsa thicknesses. G-30 yog nruj dua li cov austenitic stainless hlau thiab ua hauj lwm-hardens yooj yim dua, uas tseem ceeb ncaj qha rau lub raj-bending thiab expansion ua hauj lwm thaum lub sij hawm fabrication thiab yuav tsum tau npaj rau hauv kev tsim ib theem zuj zus.

Dab tsi yog Cov Qauv Tsim thiab Kev Ua Haujlwm Li Cas rau G-30 Evaporator Tubes?

G-30 ua tau zoo nyob thoob plaws tag nrho 30-54% P2O5 concentration ntau thiab mus txog 121℃hauv ntub dej tiag-cov txheej txheem kua qaub, tab sis cov neeg tsim qauv yuav tsum kho cov kab mob chloride hauv zos - tsis yog cov kua qaub ntau zog - raws li kev tswj hwm kev txwv tsis pub muaj kev sib txhuam, thiab yuav tsum saib xyuas tshwj xeeb - G-30 tus kheej cov ntaub ntawv hydrochloric acid qhia tau hais tias ntawm qee qhov kev sib xyaw nruab nrab-thiab-kub ua ke.

Haynes International's hydrochloric acid cov lus qhia tau hais tias tus nqi corrosion tau nce siab ntawm qee qhov nruab nrab ntawm qee qhov xwm txheej - piv txwv li, 2.5% HCl ntawm 93℃(200℃F) dhia mus rau 4.23 mm / y, thiab boiling 2 -2.5% HCl nce mus txog 9.47- 12.6 mm. zoo- coj tus nqi ntawm ob qho tib si qis dua thiab siab dua qhov siab nyob ze. Qhov kev coj cwj pwm tsis zoo no yog ib qho kev ceeb toom tias iso-corrosion diagrams thiab concentration tables yuav tsum tau nyeem ntawm qhov tseeb, hauv zos acid chemistry xav tau ntawm lub raj phab ntsa (xws li cov concentration los ntawm boiling los yog evaporation txoj cai ntawm qhov chaw), tsis yog cov nominal bulk txheej txheem concentration.

• Kev taw qhia tsim thiab kev ua haujlwm:Taug qab chloride thiab dawb -sulfuric- acid impurity theem nyob rau hauv cov txheej txheem acid, vim cov no - tsis yog lub nominal P2O5 concentration - yog dab tsi ua rau tube corrosion.
• Kev taw qhia tsim thiab kev ua haujlwm:Teem sijhawm ib ntus kev tu thiab tshuaj xyuas raws li teev thiab tso nyiaj, txij li G-30's crevice-corrosion pib (25-45℃hauv kev ntsuas nrawm) tuaj yeem mus txog qhov twg fouling concentrates chlorides hauv zos.
• Kev taw qhia tsim thiab kev ua haujlwm:Tsis txhob tsim cov qauv uas ua kom muaj zog hydrochloric acid hauv zos rau hauv 2-3% thaj tsam ntawm qhov kub siab, qhov twg G-30 tus kheej cov ntaub ntawv qhia txog qhov tsis sib xws ntawm corrosion-rate spike.
• Kev taw qhia tsim thiab kev ua haujlwm:Qhov twg sulfuric acid nqa tawm txawv txav los yog tsis tu ncua mus txog 90% concentration ntawm lub raj phab ntsa, soj ntsuam Alloy 625 los yog HASTELLOY G-35 ua lwm txoj kev txuag.
• Kev taw qhia tsim thiab kev ua haujlwm:Re-anneal tubing tom qab txias- ua haujlwm lossis khoov ntau tshaj li 7% sab nraud-fiber elongation kom rov ua kom muaj zog corrosion ua ntej ua haujlwm.

Cov lus nug nquag

Q: Vim li cas Hastelloy G-30 siv rau phosphoric acid evaporator raj?

A: G-30's siab chromium cov ntsiab lus tiv thaiv lub cim oxidizing ntawm ntub- txheej txheem phosphoric acid thiab nitric-acid paug, thaum nws cov molybdenum thiab tooj liab cov ntsiab lus tiv thaiv sulfuric acid impurity tam sim no nyob rau hauv txhua txhua ntub dej - txheej txheem kwj. Haynes International npe P2O5 evaporator raj ua ib qho ntawm cov hlau alloy ob daim ntawv thov tseem ceeb, txhawb nqa los ntawm ob qho tib si reagent - qib thiab cov txheej txheem ntub dej tiag tiag.

Q: Puas yog G-30's corrosion kuj tuav ntawm tag nrho 54% P2O5 concentration siv nyob rau hauv kev lag luam evaporators?

A: Yog lawm. Reagent- qib boiling phosphoric acid cov ntaub ntawv qhia G-30 tus nqi corrosion tsuas yog maj mam hla cov concentration ntau, nyob rau hauv 0.1-0.2 mm / y thaj tsam ntawm 54-60% P2O5 - zoo nyob rau hauv ib qho yooj yim tsim nyiaj tso cai.

Q: Dab tsi yog qhov kev pheej hmoo corrosion loj tshaj plaws rau G-30 raj hauv kev pabcuam evaporator?

A: Chloride-tsav pitting thiab crevice corrosion hauv qab nplai thiab deposits, tsis sib xws acid nres rau ntawm qhov chaw huv si. Cov qauv ntsuas nrawm qhia G-30's pitting thiab crevice-corrosion pib ntawm 25-55 degree, uas yog vim li cas ib ntus tu thiab tshuaj xyuas hauv qab fouling tseem ceeb tsis hais txog kev xaiv alloy.

Q: Puas yog Hastelloy G-30 zoo dua Alloy 625 rau phosphoric acid evaporators?

A: Nws nyob ntawm qhov twg impurity dominates. Haynes International tus kheej cov ntaub ntawv sib piv qhia tau hais tias G-30 ua ntej ntawm 625 hauv hydrochloric acid, tab sis 625 tuav me ntsis ntug hauv sulfuric acid. Qhov twg sulfuric acid nqa qhov siab txawv txav, 625 lossis siab dua-chromium HASTELLOY G-35 yuav yog qhov tshwj xeeb tshaj plaws.

Q: Puas yog vuam txo G-30's corrosion kuj nyob rau hauv evaporator raj fabrication?

A: Feem ntau tsis muaj. Luam tawm weld-hlau- piv-wrought cov ntaub ntawv qhia tsuas yog qhov sib txawv me me ntawm feem ntau sulfuric thiab hydrochloric acid cov xwm txheej cuam tshuam rau kev pabcuam evaporator, nrog rau ob qho tib si weld hlau thiab wrought puag hlau uas qhia txog kev sib tw, chemistry-tsav tau nce tsuas yog ntawm qhov mob hnyav tshaj plaws kuaj (90% sulfuric acid).

Q: G-30 lub thermal conductivity piv rau lwm cov khoom siv hluav taws xob sib txuas li cas?

A: G-30's thermal conductivity (kwv yees li 10 W / m·℃ntawm chav tsev kub) yog qis dua tooj liab alloys thiab carbon hlau, yog li tshav kub- hloov chaw yuav tsum loj raws li. Nyob rau hauv kev xyaum, qhov no yog ib feem offset vim hais tias G-30 tus corrosion kuj tso cai rau ib tug thinner raj phab ntsa dua ib tug tsawg-resistant alloy yuav xav tau rau tib lub neej kev pab cuam.