Thaum lub sij hawm tsim kho los yog kho dua tshiab, cov khoom siv refractory muaj ntau heev. Cov ntaub ntawv no poob rau hauv ob pawg tseem ceeb: preformedrefractory bricksthiab tsis yog -preformedrefractory mortars. Ob hom yuav tsum tau dej thaum lub sij hawm installation -refractory mortar siv rau cov ntaub pua tsev txaj muaj cov dej noo nyob rau hauv lub hauv paus, thaum castable thiab phom refractories yuav tsum txhob txwm txhob txwm ntxiv dej thaum lub sij hawm sib tov thiab daim ntawv thov. Yog li ntawd, cov khoom tsim kho tshiab lossis kho qhov cub pib muaj nyob rau hauv "ntub-ntev" mob.
Moisture nyob rau hauv refractory masonry muaj nyob rau hauv ob hom: (1) dawb dej (tseem hu ua dej saum npoo), uas yog lub cev adsorbed los yog entrapped thiab pom muaj nyob rau ntawm masonry nto; thiab (2) chemically khi dej (los yog cov dej crystalline), muab tso rau hauv cov khoom siv lead ua lattice ntawm hydrated theem tsim thaum lub sij hawm teeb tsa. Ob daim ntawv no ua rau muaj kev pheej hmoo loj rau kev ncaj ncees thiab kev ua haujlwm ntev -; Yog li ntawd, kev tswj xyuas thermal kom qhuav (piv txwv li, rauv- ziab) txheej txheem yog qhov yuav tsum tau ua ua ntej ua haujlwm rau qhov cub.
Kev khaws cia ntawm cov dej noo nyob rau hauv cov ntaub ntawv refractory entails peb qhov teeb meem tseem ceeb:
Ua ntej, cov cua kub ntxov ntxov uas tsis muaj qhov ziab kom qhuav tuaj yeem ua rau lub zog sab hauv siab tshaj lub zog ntsuab ntawm cov khoom siv hluav taws xob tsis zoo, ua rau tawg, tawg, lossis delamination ntawm phab ntsa thiab lub ru tsev.
Thib ob, thermally induced vaporization ntawm noo noo ua rau reactive dej vapor, inducing steep thermal gradients thiab txhawb ntau tshaj carbon monoxide (CO) tiam- ob qho tib si uas ua rau kom degradation ntawm refractory hauv ob sab phlu thiab cuam tshuam kev ua hauj lwm ntev.
Thib peb, cov dej dawb pab txhawb kev tsiv teb tsaws chaw alkali thiab efflorescence ("realkali"), tshwj xeeb tshaj yog nyob rau hauv cov av noo thiab qis - qhov kub thiab txias.
Qhov tshwm sim ntawm realkali manifests li dawb, powdery deposits (feem ntau piav raws li "bloom" los yog "frosting"), nto sanding, los yog plua plav ntawm kho refractory nto. Nws tshwm sim feem ntau thaum lub caij txias - huab cua kev teeb tsa thaum cov tshuaj khib nyiab refractory uas muaj cov kua qaub alkali hlau oxides (piv txwv li, Na₂O, K₂O) hnov mob nrog cov dej sib tov los ua alkaline hydroxides thiab colloidal silicates. Cov tsiaj no tsiv mus los ntawm kev ua haujlwm capillary rau saum npoo, qhov uas evaporation concentrates lawv mus rau hauv xoob adherent, hygroscopic dawb precipitates-yog li impairing nto cohesion, abrasion kuj, thiab tshuaj stability.
Tsis tas li ntawd, cov dej tsis muaj seem ua rau muaj kev kub ntxhov siab ntau dua -kub degradation mechanisms. Nyob rau hauv cov kev pab cuam, cov ntaub ntawv refractory yog raug erosive nres los ntawm cov khoom me me, nplaim taws, thiab corrosive gases. Txawm hais tias kev yaig ib leeg zuj zus zuj zus, qhov muaj dej dawb ua kom cov txheej txheem no los ntawm kev txhawb nqa hydrothermal cov tshuaj tiv thaiv, ua kom cov theem decomposition, thiab pab txhawb microcrack propagation - thaum kawg txo cov neeg kho tshuab lub zog, thermal shock resistance, thiab tag nrho cov kev pab cuam lub neej.
Yog li ntawd, qhov cub- ziab yog ib kauj ruam tseem ceeb ntawm ob qho tib si tshiab kiln commissioning thiab refractory kho. Qhov kev tswj xyuas cua sov no ua haujlwm rau ob lub hom phiaj tseem ceeb: (1) kev tshem tawm txhua yam dej noo-dawb thiab khi- ntawm gradient- tsav diffusion thiab nto evaporation; thiab (2) maj mam preheating ntawm refractory matrix kom induce beneficial theem transformations thiab sintering. Thaum ziab, dej vapor tsiv tawm sab nraud ntawm sab hauv mus rau qhov chaw kub, qhov chaw nws evaporates; concurrently, sab hauv dej tsis tu ncua replenishes lub evaporating pem hauv ntej, xyuas kom meej lub cev qhuav dej tsis muaj thermal shock los yog cov yam ntxwv puas.
