在固體廢物(wu)處理(li)焚燒爐(lu)的設計過程中,其(qi)爐(lu)襯材(cai)料的設計應遵(zun)循以下規則(ze):
爐(lu)襯(chen)材(cai)(cai)(cai)料(liao)(liao)(liao)要(yao)根(gen)據爐(lu)膛溫度(du)的(de)(de)(de)高(gao)低選用能承受焚燒(shao)(shao)溫度(du)的(de)(de)(de)耐(nai)(nai)火(huo)(huo)材(cai)(cai)(cai)料(liao)(liao)(liao)及(ji)(ji)(ji)隔熱材(cai)(cai)(cai)料(liao)(liao)(liao),并(bing)應考慮(lv)被焚燒(shao)(shao)廢(fei)物(wu)及(ji)(ji)(ji)焚燒(shao)(shao)產物(wu)對爐(lu)襯(chen)的(de)(de)(de)腐蝕(shi)性(xing)。焚燒(shao)(shao)堿性(xing)廢(fei)水時,燃燒(shao)(shao)產物(wu)中的(de)(de)(de)堿性(xing)熔融物(wu)對普通黏土耐(nai)(nai)火(huo)(huo)磚腐蝕(shi)性(xing)很(hen)強,因此(ci)要(yao)選用氧化鋁含量較高(gao)的(de)(de)(de)高(gao)鋁耐(nai)(nai)火(huo)(huo)材(cai)(cai)(cai)料(liao)(liao)(liao),或選用抗(kang)堿性(xing)腐蝕(shi)更好的(de)(de)(de)鉻鎂質(zhi)(zhi)、鎂質(zhi)(zhi)及(ji)(ji)(ji)鋁鎂質(zhi)(zhi)耐(nai)(nai)火(huo)(huo)材(cai)(cai)(cai)料(liao)(liao)(liao)。為(wei)了抵抗(kang)鹽堿等(deng)介質(zhi)(zhi)的(de)(de)(de)滲透和浸蝕(shi),并(bing)提(ti)高(gao)材(cai)(cai)(cai)質(zhi)(zhi)的(de)(de)(de)抗(kang)渣性(xing),一般應選用氣孔率較小的(de)(de)(de)材(cai)(cai)(cai)質(zhi)(zhi)。
選(xuan)(xuan)用(yong)(yong)(yong)焚燒爐(lu)(lu)爐(lu)(lu)襯材(cai)料時(shi),應注意爐(lu)(lu)內不(bu)(bu)(bu)同部(bu)(bu)(bu)位(wei)的(de)(de)溫度(du)和腐蝕(shi)(shi)情況,根據不(bu)(bu)(bu)同部(bu)(bu)(bu)位(wei)工(gong)作(zuo)條(tiao)(tiao)(tiao)件(jian)采用(yong)(yong)(yong)不(bu)(bu)(bu)同等(deng)級的(de)(de)材(cai)質。如(ru)燃燒室.高溫度(du)為(wei)1400~1600℃,可選(xuan)(xuan)用(yong)(yong)(yong)含Al2O3=90%的(de)(de)剛玉磚;爐(lu)(lu)膛(tang)上部(bu)(bu)(bu)工(gong)作(zuo)溫度(du)為(wei)900~1000℃,錐(zhui)部(bu)(bu)(bu)設有(you)廢(fei)液噴嘴,可選(xuan)(xuan)用(yong)(yong)(yong)含Al2O3>75%的(de)(de)高鋁磚;爐(lu)(lu)膛(tang)中(zhong)(zhong)(zhong)部(bu)(bu)(bu)溫度(du)為(wei)900℃,但熔融(rong)(rong)的(de)(de)鹽堿沿爐(lu)(lu)襯下流,爐(lu)(lu)襯腐蝕(shi)(shi)較(jiao)(jiao)重(zhong),可選(xuan)(xuan)用(yong)(yong)(yong)一等(deng)高鋁磚;爐(lu)(lu)膛(tang)下部(bu)(bu)(bu)工(gong)作(zuo)條(tiao)(tiao)(tiao)件(jian)基本和爐(lu)(lu)膛(tang)中(zhong)(zhong)(zhong)部(bu)(bu)(bu)相同,當燃燒產物(wu)中(zhong)(zhong)(zhong)有(you)大量熔融(rong)(rong)鹽堿時(shi),因熔融(rong)(rong)物(wu)料在斜坡上聚集(ji),停留(liu)時(shi)問長,易滲(shen)入耐火材(cai)料中(zhong)(zhong)(zhong),如(ru)有(you)Na2CO3時(shi)腐蝕(shi)(shi)嚴(yan)重(zhong),因此工(gong)作(zuo)條(tiao)(tiao)(tiao)件(jian)比爐(lu)(lu)膛(tang)中(zhong)(zhong)(zhong)部(bu)(bu)(bu)惡(e)劣,應選(xuan)(xuan)用(yong)(yong)(yong)孔隙率較(jiao)(jiao)低的(de)(de)致(zhi)密性材(cai)料,如(ru)選(xuan)(xuan)用(yong)(yong)(yong)電熔耐火材(cai)料制品等(deng)。要求襯里不(bu)(bu)(bu)腐蝕(shi)(shi)、不(bu)(bu)(bu)損壞是不(bu)(bu)(bu)可能的(de)(de)。通(tong)常在有(you)Na2SO3、NaOH腐蝕(shi)(shi)時(shi),采用(yong)(yong)(yong)較(jiao)(jiao)好(hao)的(de)(de)材(cai)質,使用(yong)(yong)(yong)壽(shou)(shou)命也只有(you)2~3年(nian)。對(dui)腐蝕(shi)(shi)性更強的(de)(de)Na2CO3、則使用(yong)(yong)(yong)壽(shou)(shou)命僅一年(nian)左右。
焚燒爐(lu)(lu)爐(lu)(lu)襯結構(gou)設計除(chu)材料(liao)的(de)(de)選用(yong)(yong)上要考(kao)慮(lv)(lv)承受(shou)高(gao)溫〔抿抗腐蝕之外,還要考(kao)慮(lv)(lv)爐(lu)(lu)襯支托架、錨固件及鋼(gang)殼鋼(gang)板材料(liao)的(de)(de)耐(nai)熱性(xing)和耐(nai)腐蝕性(xing),以(yi)(yi)及合理(li)的(de)(de)爐(lu)(lu)襯厚度(du)(du)等問(wen)題(ti)。應采用(yong)(yong)整(zheng)體(ti)性(xing)、嚴(yan)密(mi)性(xing)好的(de)(de)耐(nai)火材料(liao)作爐(lu)(lu)襯,如采用(yong)(yong)耐(nai)熱混凝土、耐(nai)火可塑料(liao)等,以(yi)(yi)減少磚(zhuan)縫(feng)的(de)(de)竄(cuan)氣。另外爐(lu)(lu)墻(qiang)厚度(du)(du)不(bu)能過大,爐(lu)(lu)壁溫度(du)(du)應較高(gao),以(yi)(yi)免酸(suan)性(xing)氣體(ti)被冷凝下來腐蝕爐(lu)(lu)壁。然而爐(lu)(lu)壁溫度(du)(du)也不(bu)應設計得過高(gao),過高(gao)的(de)(de)溫度(du)(du)會(hui)引起殼板變形(xing),影響環境。