Thaum Liquid Nitrogen ntsib hluav taws xob - Ua kom pom qhov qis qis heev -Tsuas Kub
Daim duab no: ib daim ntawm cov cuab yeej muaj nyob ntawm qhov kub ntawm 196 degrees Celsius, qhov kub ntawm cov kua nitrogen. Pab neeg saib xyuas yuav tsum tau nqa ib cheeb tsam tshwj xeeb mus rau qhov kub thiab txias, tab sis lub sijhawm lub zog siv rau cov qauv cua sov, qee yam tawg. Lub sheath splits. Lub tshuab cua sov tuag hauv cov xuab moos. Qhov xwm txheej no tshwm sim ntau zaus ntau dua li ntau tus xav lees paub hauv cov chaw cryogenic, cov khoom siv hluav taws xob semiconductor, thiab cov tshuaj khov kho- ua haujlwm kom qhuav.
Kev sib tw nrog cua sov ntawm cov kua nitrogen txias tsis yog tiag tiag txog kev tsim kom muaj cua sov txaus. Qhov tseeb, qhov teeb meem yog qhov sib txawv heev. Standard cartridge heaters ua kom sov zoo. Qhov teeb meem yog tias cov ntaub ntawv uas lawv tau ua los ntawm tsuas yog tsis tuaj yeem tswj hwm qhov kub siab tshaj plaws uas tshwm sim thaum lub tshuab hluav taws xob tsis zoo hauv lub tshuab hluav taws xob mus los ntawm qhov txias txias mus rau ntau pua degrees Celsius hauv ib lub vib nas this.
Nov yog qhov tshwm sim. Thaum cov hluav taws xob ntws los ntawm cov hlau tsis kam ntawm lub tshuab cua sov ntawm lub tshuab cua sov, cov cua sov ua rau ntawm cov hlau nto yuav luag tam sim ntawd. Lub magnesium oxide rwb thaiv tsev thiab cov hlau sheath nyob ib ncig ntawm nws, txawm li cas los xij, nyob ntawm qhov kub ntawm cov kua nitrogen. Thaum thawj ob peb vib nas this ntawm kev ua haujlwm, kub gradients ntau tshaj 800 degrees Celsius ib centimeter daim ntawv hla cov khoom sib cuam tshuam. Standard stainless hlau 304 sheaths, uas ua hauj lwm zoo kawg nkaus zoo rau kev lag luam cua sov, ua nkig ntawm cov kub thiab tawg nyob rau hauv cov neeg kho tshuab kev nyuaj siab.
Lub physics qab qhov no yog ncaj nraim. Cov hlau feem ntau dhau los ua cov zawv zawg - mus rau - kev hloov pauv hloov raws li qhov kub thiab txias. Nyob rau hauv chav tsev kub, stainless hlau sheath tuaj yeem khoov me ntsis yam tsis muaj kev tawg. Thaum rho tawm 196 degrees, tib cov khoom ntawd poob nws qhov yooj yim thiab pob txha nyob rau hauv thermal expansion stress. Qhov no yog vim li cas cryogenic- ntsuas cov tshuab cua sov yuav tsum muaj cov ntaub ntawv tshwj xeeb xws li Inconel 625, uas nyob twj ywm txawm tias los ntawm kev hloov pauv kub ceev los ntawm cov xwm txheej cryogenic tag nrho mus txog 980 degrees Celsius.
Lwm qhov tseem ceeb uas feem ntau tau saib tsis pom yog noo noo. High-purity magnesium oxide rwb thaiv tsev ua haujlwm zoo heev ntawm kev ua cua sov thaum thaiv hluav taws xob, tab sis nws muaj ib qho tsis muaj zog. Nws absorbs noo noo los ntawm huab cua. Cov dej vapor daig hauv lub tshuab rhaub dej thaum lub sijhawm tsim khoom, lossis qhov uas nkag los ntawm cov ntsaws ruaj ruaj tsis zoo, yuav khov ntawm cov kua nitrogen txias. Thaum dej khov, nws nthuav dav li cuaj feem pua ntawm qhov ntim. Nyob rau hauv ib lub qhov cub kaw, qhov kev nthuav dav no tsim kom muaj kev txaus siab rau kev puas tsuaj ntawm cov rwb thaiv tsev los yog tshem tawm cov ntaub qhwv los ntawm qhov kawg seals. Cov khoom siv hluav taws xob zoo tshaj plaws tsim los rau cov kev pabcuam cryogenic nyob qhov no los ntawm lub tshuab nqus tsev- cov txheej txheem sau cov txheej txheem uas tshem tawm cov voids, ua raws li hermetic sealing siv ceramic-rau-hlau sib txuas lossis tshwj xeeb epoxy compounds ntsuas rau lub luag haujlwm cryogenic. Tom qab-kev tsim khoom ci{12}} tawm haujlwm ntawm 120 txog 150 degrees Celsius kom ntseeg tau tias tag nrho cov seem seem raug tshem tawm ua ntej xa khoom.
Cov cwj pwm hluav taws xob ntawm cov hlau tsis kam kuj hloov pauv ntawm qhov kub thiab txias. Nickel-chromium alloys, uas yog cov khoom siv rau cov khoom siv hluav taws xob cua sov, muaj li ntawm 10 mus rau 15 feem pua tsawg tiv thaiv ntawm rho tawm 40 degrees dua li lawv ua nyob rau hauv chav tsev kub. Ntawm cov kua nitrogen kub, cov nyhuv no tseem tshaj tawm. Kev tiv thaiv qis dua txhais tau hais tias lub rhaub dej rub tawm ntau dua tam sim no thiab tsim hluav taws xob ntau dua thaum pib los ntawm lub xeev txias. Cov yam ntxwv no tuaj yeem muaj txiaj ntsig zoo rau kev kov yeej cov thermal dab dej loj heev ntawm qhov chaw ib puag ncig cryogenic, tab sis nws kuj tseem ua rau muaj kev ntxhov siab ntxiv rau cov hlau tsis kam thiab yuav tsum tau tswj cov tshuab muaj peev xwm tuav tau ib ntus overloads.
Raws li kev paub dhau los, ib qho kev txiav txim siab tseem ceeb tshaj plaws rau txhua daim ntawv thov cua sov cryogenic yog xaiv cov khoom siv. Lub sheath alloy, lub rwb thaiv tsev compaction ceev, lub foob hom, thiab txawm cov hlau lead cov ntaub ntawv tseem ceeb tshaj li wattage ratings ib leeg. Lub tshuab tso cua sov uas zoo ib yam rau cov qauv kev lag luam sab nraud tuaj yeem ua tsis tau zoo rau cov kev pabcuam kua nitrogen rau sab hauv. Qhov sib txawv uas cais cov kev ua tau zoo cryogenic los ntawm kev ua tsis tiav sai yog muab zais rau hauv kev tsim kho sab hauv thiab cov khoom siv tshwj xeeb.
Rau cov ntawv thov uas muaj cov kua nitrogen cua sov, lub tshuab rhaub cartridge yuav tsum tau tsim tshwj xeeb rau tag nrho qhov kub thiab txias nws yuav ua tau, tsis yog qhov ruaj khov - lub xeev kev khiav hauj lwm kub. Qhov no txhais tau hais tias xav txog thermal shock thaum pib, cov neeg kho tshuab kev ntxhov siab ntawm kev rov ua dua thermal cycling, tiv thaiv kev ya raws, thiab hloov hluav taws xob ntawm cov ntaub ntawv tiv thaiv thoob plaws qhov kub thiab txias. Thaum cov xwm txheej no raug hais kom raug, lub tshuab hluav taws xob cartridge tuaj yeem xa cov kev pabcuam txhim khu kev qha hauv qee qhov kev xav tau thermal tshaj plaws nyob rau hauv kev lag luam niaj hnub no.
