Cov dej ntws los ntawm lub raj tooj cua kub hloov pauv ntawm qhov nrawm nrawm tuaj yeem coj tus yam ntxwv zoo li lub dav hlau microscopic abrasive tiv thaiv cov txheej nyias oxide tiv thaiv cov hlau nto. Thaum cov yeeb yaj kiab tiv thaiv no tau muab tshem tawm lawm, qhov chaw hauv cheeb tsam corrosion nrawm nrawm, khawb tob, nees nees- zoo li lub qhov rau hauv lub raj phab ntsa. Daim ntawv no ntawm kev puas tsuaj, hu ua impingement nres, yog ib qho ntawm feem ntau ua rau tsis ua hauj lwm ntxov ntxov hauv Admiralty tooj dag cua txias tshuab. Txoj kev tiv thaiv zoo tshaj plaws yog ceev faj tswj cov dej nrawm.
Nkag siab txog kev sib raug zoo ntawmdej velocity admiralty tooj dag impingement nresNws yog ib qho tseem ceeb thaum tsim cov condensers uas txhim khu kev qha dej qab zib, txias, thiab plhaub-thiab- tube exchangers.
Nkag siab txog Admiralty Brass Protection Mechanisms
Lub luag haujlwm ntawm Oxide Film
Admiralty tooj dag resists dej tsis qab ntsev los ntawm kev tsim ntawm nyias, adherent cuprous oxide nto zaj duab xis.
Cov txheej tiv thaiv no ua raws li qhov thaiv ntawm cov hlau thiab cov dej nyob ib puag ncig, ua rau qeeb ntxiv corrosion thiab stabilizing lub raj nto thaum lub sijhawm ua haujlwm.
Cov oxide zaj duab xis tsim ib txwm nyob rau hauv cov xwm txheej tsim nyog thiab nyob ntawm:
Tsim nyog chemistry dej
Nruab nrab khiav ceev
Cov qib oxygen ruaj khov
Ntxuav lub raj qhov chaw
Thaum cov txheej txheem tiv thaiv no tseem nyob ruaj khov, Admiralty tooj dag tuaj yeem muab ntau xyoo ntawm kev pabcuam txhim khu kev qha hauv cov dej txias txias.
Dab tsi yog Impingement Attack?
Mechanical Destruction of the Protective Film
Impingement nres tshwm sim thaum cov dej ntws tawm lub cev tshem tawm cov yeeb yaj kiab tiv thaiv oxide sai dua li nws tuaj yeem hloov kho.
Cov dej ceev ceev yog tus yeeb ncuab ntawm tooj dag tiv thaiv npuas thaum muaj kev kub ntxhov ntau dhau.
Thaum liab qab hlau yuav raug:
Corrosion accelerates hauv zos
Tsis sib xws hlau poob tsim
Qhov tob tob tsim sai heev
Tube leakage thaum kawg tshwm sim
Impingement nres yog tshwj xeeb yog txhoj puab heev thaum lub siab tshaj tawm ua ke nrog:
Kev kub ntxhov
Suspended solids
Cua npuas
Sudden directional flow pauv
Paub txog qhov kev puas tsuaj
Yam ntxwv tsos
Kev tawm tsam impingement ua kom pom qhov txawv txav.
Qhov kev puas tsuaj feem ntau muaj xws li:
Smooth, scooped - tawm pits
Horseshoe-zoo li kab noj hniav
Ntxuav cov hlau nplaum
Cov qauv kev taw qhia ua ke nrog kev ntws
Tsis zoo li feem ntau corrosion, uas zoo nkaus li zoo ib yam, impingement nres tsim sharply localized puas concentrated nyob rau hauv siab -turbulence regions.
Vim li cas Tube Inlets thiaj li yooj yim dua
Transition Turbulence
Tube inlet cheeb tsam yog qhov chaw tshaj plaws rau impingement nres.
Raws li cov dej tawm ntawm lub taub hau thiab nkag mus rau lub raj me me, cov kev hloov pauv sai sai.
Qhov kev hloov pauv no tsim:
Siab ceev hauv zos
Kev kub ntxhov
Flow sib cais
Eddy tsim
Qhov tshwm sim ntawm kev ntxhov siab ntawm cov oxide zaj duab xis tuaj yeem tshaj nws lub peev xwm los txuas rau lub raj nto.
Lwm qhov chaw tsis muaj zog muaj xws li:
Khoov
Rov qab seem
Cov cheeb tsam tom qab kev thaiv
Ib feem thaiv cov hlab
Pom zoo Velocity txwv
Standard Admiralty Brass
Rau tus qauv Admiralty tooj dag ua haujlwm hauv cov dej huv huv, qhov kev lees paub dav dav tshaj plaws yog kwv yees li:
vmax≈1.5 m/sv_{\\max} \\approx 1.5\\ \\mathrm{m/s}vmax≈1.5 m/s
Hauv qab qhov pib no, cov oxide zaj duab xis feem ntau nyob ruaj khov thiab muaj peev xwm tiv thaiv phab ntsa ntawm lub raj los ntawm kev yaig nrawm dua -corrosion.
Tshaj qhov nrawm no ua rau muaj kev pheej hmoo ntawm kev tshem tawm cov yeeb yaj kiab thiab kev tawm tsam hauv zos.
Hlau-Thiab Admiralty Brass
Txhim kho Erosion Resistance
Hauv cov tshuab uas xav tau tus nqi ntws siab dua, hlau - kho Admiralty tooj dag tuaj yeem muab cov tshuaj tiv thaiv ntau dua.
Qhov kev hloov pauv no muaj cov hlau me me ntxiv uas txhim kho cov qauv thiab kev ruaj ntseg ntawm oxide zaj duab xis.
Lub zog tiv thaiv txheej muaj:
Zoo dua erosion kuj
Txhim kho zaj duab xis adhesion
Ntau dua turbulence kam rau ua
Txo impingement rhiab heev
Raws li kev huv huv - dej, hlau- kho Admiralty tooj dag tuaj yeem ua rau siab tshaj tawm mus txog:
vmax≈2.5 m/sv_{\\max} \\approx 2.5\\ \\mathrm{m/s}vmax≈2.5 m/s
Qhov kev nthuav dav kev ua haujlwm no tuaj yeem tso cai rau kev sib hloov pauv ntau dua thaum tuav lub raj siv tau.
Qhov cuam tshuam ntawm Dej Zoo
Kev nrawm tsis yog qhov tseem ceeb xwb
Txawm hais tias kev tshaj tawm ua lub luag haujlwm tseem ceeb, ntau yam xwm txheej ntxiv cuam tshuam rau kev pheej hmoo cuam tshuam:
Xuab zeb los yog tshem tawm cov khib nyiab
Dissolved oxygen cov ntsiab lus
Dej chemistry
Kub
Biological fouling
Ntws pulsation
Txawm tias me ntsis velocities yuav ua puas yog hais tias muaj abrasive hais.
Hloov pauv, tshwj xeeb tshaj yog cov dej huv tuaj yeem tso cai me ntsis nrawm dua yam tsis muaj kev tawm tsam tam sim.
Qhov kawg erosion -corrosion threshold yog li ntawd ib txwm muaj kev sib koom ua ke ntawm kev tshaj tawm, dej chemistry, thiab turbulence siv.
Lwm cov khoom siv rau kev nrawm dua
Thaum Brass ncav cuag nws qhov txwv
Yog tias cov txheej txheem cua txias tsim yuav tsum muaj qhov nrawm nrawm nrawm, lwm cov alloys yuav tsim nyog.
90-10 tooj liab-nickel feem ntau raug xaiv vim nws qhov kev tiv thaiv zoo tshaj plaws rau kev yaig-corrosion nyob rau hauv cov dej khov thiab dej tsis huv.
Piv nrog Admiralty tooj dag, tooj liab -nickel alloys muab:
Cov yeeb yaj kiab tiv thaiv ruaj khov dua
Zoo siab -kev ua tau zoo
Txhim khu kev tiv thaiv rau impingement nres
Kev kam rau siab ntau dua rau kev cuam tshuam ntws
Yog li xaiv cov khoom siv yuav tsum ua raws li cov xwm txheej hydraulic tiag tiag es tsis yog cia siab rau cov khoom siv thawj zaug xwb.
Tsim rau Ntev Tube Lub Neej
Flow Management yog qhov tseem ceeb
Ntau qhov kev tsim qauv pab txo qis kev pheej hmoo ntawm impingement nres:
Limiting zuag qhia tag nrho khiav ceev
Txo cov kev hloov pauv sai sai
Txo turbulence ntawm inlets
Tsis txhob thaiv cov hlab ib nrab
Kev tswj xyuas cov dej huv
Tiv thaiv cov kab mob abrasive
Ua tib zoo header thiab raj-daim ntawv tsim tuaj yeem txo qhov kev kub ntxhov hauv cheeb tsam thiab txuas ntxiv kev pab cuam lub neej.
Xaus
Kev tswj cov dej nrawm tseem yog ib qho tseem ceeb tshaj plaws hauv kev tiv thaiv kev tawm tsam hauv Admiralty brass heat exchanger tubs. Cov hlau yog nyob ntawm qhov muag heev tab sis muaj txiaj ntsig zoo cuprous oxide zaj duab xis rau kev tiv thaiv corrosion, thiab ntau dhau turbulence los yog ntws tshaj tawm tuaj yeem kho cov txheej txheem no los ntawm lub raj nto.
Rau tus qauv Admiralty tooj dag, tuav cov dej tshiab tshaj tawm hauv qab li ntawm 1.5 m / s muab kev tiv thaiv zoo tshaj plaws tiv thaiv kev yaig - kev puas tsuaj. Yog tias tsis muaj kev khiav dej num ntau dua, cov hlau- kho Admiralty tooj dag muaj kev txhim kho oxide zaj duab xis ruaj khov thiab tuaj yeem ua rau siab tshaj 2.5 m / s nyob rau hauv huv huv - dej. Hauv cov cheeb tsam uas xav tau ntau dua, tooj liab -nickel alloys tuaj yeem muab kev nyab xeeb ntev dua - cov tshuaj.
Thaum kawg, kev sib tw ua tiav kev tsim qauv yuav tsum muaj kev sib txuam nrog cov xwm txheej hydraulic rau cov kev txwv corrosion ntawm cov khoom xaiv. Hauv ntau lub tshuab ua kom txias, lub neej ua haujlwm ntev nyob ntawm kev tiv thaiv tshuaj tua kab mob thiab ntau dua ntawm kev hwm qhov sib txawv ntawm cov dej ntws maj mam hla cov hlau nto thiab dej tawm tsam nws nrog kev puas tsuaj.
