Seawater desalination muab qhov xav tau tshwj xeeb ntawm cov khoom siv hluav taws xob sib pauv. Kev sib xyaw ua ke ntawm cov tshuaj chloride siab, kev ua haujlwm siab, thiab cov dej ntws tsis tu ncua ua rau ib puag ncig uas cov khoom siv tau yooj yim degrade. Titanium muaj kev tiv thaiv tshwj xeeb rau cov dej hiav txwv thiab cov tshuaj chloride-induced corrosion, tsis tau cov ntaub ntawv titanium tube tseem ceeb heev rau cov khoom loj - nplai desalination. Qhov kev txwv kev lag luam no tau ua rau kev lag luam mus rau qhov kev daws teeb meem zoo nkauj: titanium-cov ntaub ntawv steel tube ua los ntawm kev sib tsoo tawg.
- Kev Sib Tw Corrosion hauv Desalination Thaum tshav kub kub Exchangers
Desalination nroj tsuag, txawm tias siv ntau-theem flash (MSF), multi-effect distillation (MED), lossis rov qab osmosis (RO) cov txheej txheem, vam khom ntau ntawm lub plhaub- thiab- raj kub exchangers. Cov koog no tuav cov brine ntawm qhov kub siab, nthuav tawm cov ntawv raj rau kev tawm tsam tsis tu ncua los ntawm chloride ions. Titanium thiab nws cov alloys pom zoo rau cov dej hiav txwv, cov tshuaj chloride, thiab cov kua dej yaig- cov khoom uas ua rau lawv cov hlau xaiv rau ntug hiav txwv dej thiab brackish- dej txias tshuab. The metal naturally forms a dense, stable oxide film when exposed to oxidizing environments, providing protection against pitting corrosion and crevice attack that plague stainless steels and copper alloys in saline service.
Qhov teeb meem yeej ib txwm yog tus nqi. Titanium yog kim, thiab fabricating tag nrho cov raj ntawv los ntawm cov khoom titanium tsav cov khoom siv nqi tshaj qhov kev txwv rau kev loj desalination installation. Qhov no yog qhov uas cov ntaub ntawv clad nkag mus rau hauv daim duab.
Explosive Vuam
Explosive welding, tseem hu ua tawg cladding, tseem yog txoj kev lag luam tseem ceeb rau kev tsim cov titanium composite daim hlau. Cov txheej txheem siv tswj detonations kom nrawm titanium cladding phaj mus rau cov hlau substrate ntawm siab tshaj tawm. Qhov cuam tshuam siab ua rau muaj kev sib txuas ntawm cov hlau sib txawv ntawm ob qhov sib txawv ntawm cov hlau sib txawv ntawm qhov kub thiab txias - cov txheej txheem vuam - lub xeev cov txheej txheem uas tsis txhob cuam tshuam cov khoom sib txuas thiab cov thermal distortion cuam tshuam nrog fusion vuam.
Qhov tshwm sim interface nthuav tawm cov yam ntxwv wavy morphology, kos npe ntawm kev ua tiav tawg vuam. Cov qauv nthwv dej ntawm lub sijhawm no, feem ntau nrog wavelengths thiab amplitudes ntsuas tau ntau pua microns, tshwm sim los ntawm cov yas shear tsis thiab khaus hauv zos nplawm thaum lub sij hawm detonation tshwm sim. Lub yoj interface muab cov cuab yeej sib cuam tshuam zoo tshaj plaws thiab kev sib koom ua ke lub zog piv rau cov kev sib tshuam tiaj tus, nrog cov ntaub ntawv shear zog ncav cuag 150-200 MPa. Hauv qee qhov kev siv, qhov sib cuam tshuam shear zog tshaj 210 MPa.
Tube Sheet Fabrication thiab kev ua tau zoo
Titanium-cov ntaub ntawv clad tube ua los ntawm kev tawg vuam ua ke ua ke titanium txheej- feem ntau yog Qib 1 lossis Qib 2 ua lag luam ntshiab titanium- nrog cov pa roj carbon steel thaub qab xws li SA516 Gr.70 lossis Q345R. titanium txheej thickness feem ntau yog li ntawm 3 mus rau 8 hli, muab kev tiv thaiv corrosion rau ntev -lub sij hawm raug dej hiav txwv. Cov hlau substrate muab cov txheej txheem lub zog thiab rigidity xav tau los pab txhawb cov hlab ntim thiab tiv taus cov khoom hnyav, thaum lub titanium cladding tuav cov corrosive brine ib puag ncig.
Lub metallurgical daim ntawv cog lus ntawm ob txheej yog ib qho tseem ceeb thiab tas mus li, ua tau raws li qhov yuav tsum tau muaj ntawm ASTM B898, tus qauv specification rau reactive thiab refractory hlau clad phaj npaj rau kev siv lub nkoj siab. Ib puas feem pua kev tshuaj ntsuam xyuas ultrasonic xyuas qhov kev ncaj ncees, nrog rau cov qauv tsim nyog feem ntau xav tau daim ntawv cog lus ntawm 98% lossis siab dua.
Cov ntaub ntawv nyiaj txiag rau titanium-cov ntaub ntawv clad tube yog qhov nyuaj. Piv nrog rau cov khoom siv titanium, clad tsim txo cov nqi khoom los ntawm 35 mus rau 50 feem pua. Qee qhov kev kwv yees tso cov nyiaj khaws cia ntawm kwv yees li 40 feem pua thaum tswj qhov sib npaug ntawm kev tiv thaiv corrosion. Qhov kev ua tau zoo ntawm tus nqi no ua rau titanium qhov zoo tshaj plaws seawater corrosion kuj nkag mus rau qhov loj -scale desalination tej yaam num uas cov khoom titanium yuav tsis siv nyiaj txiag.
Fabrication yuav tsum tau ua tib zoo saib xyuas kom meej. Tube qhov drilling hauv clad daim hlau xav tau carbide-tipped tooling nrog txiav ceev ceev nyob rau hauv 15-20 m / min ntau yam los tiv thaiv titanium txheej delamination. Tube-rau- raj xaim vuam yuav tsum siv cov roj inert shielding-feem ntau argon-nrog cov tam sim no nyob rau hauv 90–110 A ntau yam kom tsis txhob muaj kev cuam tshuam oxidation. Qhov ntsuas kub tsim yuav tsum nyob twj ywm ntawm lossis qis dua 300℃kom txo tau qhov kev pheej hmoo ntawm hydrogen embrittlement. Kev hloov cov pob qij txha ntawm titanium clad tube nplooj ntawv thiab cov kav dej steel feem ntau ua tiav siv titanium- cov hlau hloov pauv.
Kev paub txog kev ua haujlwm nrog cov khoom tawg -welded titanium-cov ntaub ntawv qhwv hauv cov kev pabcuam desalination tau zoo. Kev ntsuas kev ua tau zoo hauv cov dej hiav txwv desalination cov nroj tsuag ua kom pom kev ua kom zoo thermal ua haujlwm zoo txawm tias nyob hauv qhov chaw siab -salinity. Lub titanium cladding tuav nws cov oxide zaj duab xis kev ncaj ncees nyob rau hauv thermal cycling tej yam kev mob, nrog rau cov ntaub ntawv ua tau zoo nyob rau hauv qhov kub ntawm qhov kub ntawm -40℃mus rau 300 degree. Kev tshawb fawb ntev ntev nyob rau hauv ib puag ncig marine qhia zoo li tsis muaj kev ntsuas corrosion tom qab kaum xyoo ntawm kev pabcuam txuas ntxiv.
Kev tsim cov titanium-clad tube sheets rau desalination daim ntawv thov ua raws li cov qauv tsim xws li ASTM B898 thiab Suav tus qauv NB/T 47002.3. Cov txheej txheem kev lees paub zoo suav nrog kev kuaj ultrasonic ntawm daim ntawv cog lus interface, kev kuaj xyuas txhua yam ntawm lub zog shear, thiab kev tshuaj xyuas qhov ntev ntawm lub raj qhov qauv. Cov qauv no xyuas kom meej tias cov ntaub ntawv clad tube ua tau raws li cov qauv kev ua tau zoo ib yam li cov khoom siv titanium hauv kev pabcuam lub nkoj siab.
Raws li cov dej hiav txwv desalination muaj peev xwm txuas ntxiv mus thoob ntiaj teb, qhov kev thov rau tus nqi -zoo corrosion- tiv thaiv cov khoom siv hluav taws xob sib pauv yuav loj tuaj. Kev tawg vuam ntawm titanium-clad steel tube nplooj ntawv muaj kev paub tab, pov thawj thev naus laus zis uas sib npaug kev ua haujlwm corrosion tiv thaiv tus nqi peev. Cov txheej txheem tsim cov ntawv cog lus metallurgical txhim khu kev qha, cov ntaub ntawv ua tau raws li cov qauv kev lag luam tsim, thiab kev ua haujlwm tau lees paub ntev - lub sijhawm ua haujlwm ntev hauv kev pabcuam dej hiav txwv. Rau desalination cog cov neeg tsim qauv thiab cov neeg ua haujlwm, titanium-cov ntaub qhwv cov ntaub ntawv sawv cev rau kev daws teeb meem rau ib qho ntawm kev lag luam cov khoom sib tw.
