Ncaj nraim faus steel kav yog faus rau hauv av, thiab electrochemical corrosion yog ib qho teeb meem uas yuav zam tsis tau. Kev tiv thaiv Cathodic yog ib txoj kev tiv thaiv uas feem ntau siv, tab sis kev tiv thaiv cathodic rau cov kav dej insulated yog qhov nyuaj dua li cov kav dej zoo tib yam.
Kev tiv thaiv Cathodic ntawm cov kav dej zoo tib yam yog qhov yooj yim - txheej txheej tiv thaiv - txheej txheej ntawm cov phab ntsa sab nrauv ntawm cov kav dej thiab tom qab ntawd siv cathodic tiv thaiv tam sim no. Tab sis cov qauv ntawm cov yeeb nkab rwb thaiv tsev yog txawv: sab nraud ntawm cov yeeb nkab steel yog cov txheej txheem polyurethane rwb thaiv tsev, thiab sab nraud ntawm txheej rwb thaiv tsev yog polyethylene txheej tiv thaiv yeeb nkab. Cov txheej rwb thaiv tsev thiab cov raj tiv thaiv sab nrauv yog ob qho tib si insulating cov ntaub ntawv, tsim cov txheej txheem rwb thaiv tsev ntawm "anti-corrosion txheej- txheej rwb thaiv tsev- txheej tiv thaiv". Txawm hais tias cov qauv no zoo rau kev txuag hluav taws xob, nws coj teeb meem rau cathodic tiv thaiv - cathodic tiv thaiv tam sim no yog thaiv los ntawm cov txheej rwb thaiv tsev thiab tsis tuaj yeem ncav cuag qhov chaw ntawm cov yeeb nkab steel. Qhov no yog qhov uas yog li ntawd -hu ua "kev tiv thaiv thawj" nyhuv.
Muaj ob txoj hauv kev los daws qhov teeb meem no. Ib qho yog muab kauv qhwv lub sacrificial anode (xws li aluminium alloy sacrificial anode sawb) rau saum npoo ntawm cov yeeb nkab steel ua ntej prefabricating txheej rwb thaiv tsev, weld lub anode core rau cov yeeb nkab lub cev ntawm qee lub sijhawm, thiab tom qab ntawd ua cov rwb thaiv tsev foaming. Nyob rau hauv txoj kev no, lub sacrificial anode yog qhwv nyob rau hauv lub rwb thaiv tsev txheej, ncaj qha tiv thaiv cov yeeb nkab steel. Lwm qhov yog tsim kom muaj kev tiv thaiv cathodic tam sim no channel los ntawm kev cuam tshuam tsawg kawg nkaus rau cov kav dej uas twb muaj lawm uas tau muab faus rau hauv av thiab qhia txog kev tiv thaiv tam sim no rau hauv txheej rwb thaiv tsev.
Cov teeb meem rwb thaiv tsev kuj yuav tsum tau them sai sai rau thaum tsim. Kev rwb thaiv tsev zoo yuav tsum tau khaws cia nruab nrab ntawm cov yeeb nkab steel ua haujlwm thiab cov yeeb nkab tiv thaiv sab nrauv, thiab cov khoom xws li zawv zawg zawv zawg yuav tsum tau ua raws li cov kev cai ntawm kev rwb thaiv tsev. Nyob rau hauv txoj kev no, lub peev xwm polarization tsis sib xws tuaj yeem tau txais nrog qhov tsawg kawg nkaus tiv thaiv tam sim no.
Kev tsim thiab kev tsim kho ntawm kev tiv thaiv cathodic yuav tsum ua raws li "Technical Specifications for Cathodic Protection of Buried Steel Pipelines" GB/T 21448-2017. Kev tiv thaiv cathodic ntawm cov kav dej insulated yog qhov nyuaj dua li cov kav dej zoo tib yam. Yog tias nws tsis pom zoo thaum lub sijhawm tsim thiab tsim kho, nws yuav nyuaj rau kev kho nws tom qab.