Cov ntawv thov tseem ceeb thiab qhov zoo ntawm Titanium thiab Titanium Alloys hauv Urea Production

Kev tsim cov urea, ib qho nruab nrab thiab muaj txiaj ntsig nitrogen chiv, suav nrog ntau yam tshuaj lom neeg. Tshwj xeeb, kev hloov pauv ntawm ammonium carbamate rau urea tsis tiav thiab yog li ntawd yuav tsum muaj kev sib cais zoo los ntawm kev sib xyaw uas muaj urea, tshaj ammonia thiab dej. Xav txog tias cov tshuaj ammonium carbamate, ib qho khoom nruab nrab tsim los ntawm qhov kub thiab txias, yog qhov tsis zoo, kev xaiv cov khoom siv zoo tshaj plaws yog qhov tseem ceeb. Titanium sawv tawm hauv qhov no vim nws cov khoom zoo heev.
Kev tshawb fawb los ntawm American Crucible Company tau qhia tias cov khoom siv titanium tuaj yeem txhim kho qhov ua tau zoo ntawm cov txheej txheem urea. Qhov no feem ntau yog vim titanium tus cwj pwm ruaj khov ntawm qhov kub thiab txias. Nyob rau hauv sib piv, stainless hlau, txawm hais tias nws muaj zoo corrosion kuj rau urea nyob rau hauv qis kub, tsub kom nws corrosion tus nqi exponentially nrog txhua txhua 10 degree nce nyob rau hauv kub. Yog li ntawd, titanium raj kub exchangers thiab titanium piping tau dhau los ua qhov tseem ceeb thiab cov cuab yeej tseem ceeb hauv urea ntau lawm cov nroj tsuag.

Rov qab rau xyoo 1960, Japanese Mitsui East Pressure Chemical Company tau ua tus thawj coj hauv kev siv titanium los ua cov khoom siv hauv ob sab hauv urea ntau lawm. Tom qab tshawb xyuas qhov kev tiv thaiv corrosion ntawm titanium los ntawm kev sim ntau, lub tuam txhab txiav txim siab los txais yuav titanium nyob rau hauv urea synthesis ntauwd thiab nws cov khoom siv ntxiv. Lub tswv yim tshiab no tsis yog tsuas yog nce cov synthesis tus nqi, tab sis kuj ua kom yooj yim cov txheej txheem ua haujlwm, txhim kho cov khoom zoo, thiab paub txog cov khoom siv loj, uas tau siv dav hauv ntiaj teb urea ntau lawm teb.
Nyob rau hauv cov txheej txheem tseem ceeb ntawm urea synthesis, lub tuam txhab Italian Nationwide Methane Pipeline Thauj kuj xaiv titanium rau nws stripper yees. Qhov no yog vim hais tias kev siv cov amines nyob rau hauv lub stripper ntauwd cais cov urea los ntawm cov khoom reactive ntawm cov txheej txheem ntau lawm ua rau cov teeb meem ntawm corrosion. Titanium qhov zoo heev corrosion kuj ua rau nws yog qhov kev xaiv zoo tshaj plaws los daws qhov teeb meem no.
Thaum xyoo 1970, Tuam Tshoj kuj tau pib tshawb nrhiav kev siv titanium hauv urea ntau lawm. Lub sijhawm ntawd, Tuam Tshoj tsim thiab tsim 240, 000 tons ntawm urea nrog cov pa roj carbon dioxide stripping ntauwd, nws cov khoom tseem ceeb xws li lub taub hau, lub raj ncaj thiab sab sauv thiab sab phaj phaj yog siv rau hauv cov khoom tawg sib xyaw titanium - steel. phaj tshuab, thiab built-in 1, 361 31mm × 31mm titanium raj. Cov cuab yeej siv tau muab tso rau hauv kev tsim khoom hauv xyoo 1979 thiab tau txiav tawm hauv xyoo 1987, thaum lub sijhawm nws tau ua haujlwm rau tag nrho 1,310 hnub thiab ua tiav 31,440 teev ntawm kev kuaj tshuaj lom neeg nrog kev ua haujlwm zoo. Tom qab ntawd, xyoo 1990, Tuam Tshoj tau ua tiav tsim thiab tsim 400mm titanium-lined synthesis ntauwd, uas tau muab tso rau hauv kev ua haujlwm hauv Anyang. Nyob rau hauv tib lub sijhawm, tus nqi corrosion ntawm titanium yog ib qho kev txiav txim siab qis dua li ntawm 316L stainless hlau, thiab kev siv cov kub siab dua, yog li coj cov txiaj ntsig kev lag luam tseem ceeb rau kev lag luam ntawm kev txuag hluav taws xob, txuag hluav taws xob thiab txuag dej.