洗(xi)滌(di)塔是(shi)一(yi)種新型的氣(qi)體凈(jing)化(hua)處理設備。它(ta)是(shi)在可(ke)浮動(dong)填料(liao)層氣(qi)體凈(jing)化(hua)器的基礎(chu)上(shang)改進而產生的,廣泛(fan)應用(yong)于工(gong)業廢(fei)氣(qi)凈(jing)化(hua)、除(chu)塵等方(fang)面(mian)的前(qian)處理,凈(jing)化(hua)效果很好。對煤氣(qi)化(hua)工(gong)藝來說,煤氣(qi)洗(xi)滌(di)不可(ke)避免,無(wu)論什么煤氣(qi)化(hua)技術都用(yong)到(dao)這一(yi)單(dan)元操作(zuo)(zuo)。由于其工(gong)作(zuo)(zuo)原理類似洗(xi)滌(di)過(guo)程(cheng),故名洗(xi)滌(di)塔。
洗(xi)(xi)滌(di)(di)塔與精餾塔類似,由(you)塔體(ti)(ti),塔板(ban),再沸器,冷(leng)凝(ning)器組(zu)成。由(you)于(yu)洗(xi)(xi)滌(di)(di)塔是進行粗(cu)分(fen)離的(de)設備(bei),所以塔板(ban)數量一般較少,通常不(bu)(bu)會(hui)超過(guo)十級。 洗(xi)(xi)滌(di)(di)塔適用(yong)于(yu)含(han)有少量粉(fen)塵的(de)混合(he)氣(qi)體(ti)(ti)分(fen)離,各組(zu)分(fen)不(bu)(bu)會(hui)發生(sheng)反應(ying),且(qie)產(chan)(chan)(chan)物(wu)(wu)應(ying)容易液(ye)(ye)(ye)化(hua),粉(fen)塵等雜(za)質(zhi)(也可以稱(cheng)之為高沸物(wu)(wu))不(bu)(bu)易液(ye)(ye)(ye)化(hua)或凝(ning)固(gu)。當(dang)(dang)混合(he)氣(qi)從(cong)洗(xi)(xi)滌(di)(di)塔中部通入洗(xi)(xi)滌(di)(di)塔,由(you)于(yu)塔板(ban)間(jian)存在產(chan)(chan)(chan)物(wu)(wu)組(zu)分(fen)液(ye)(ye)(ye)體(ti)(ti),產(chan)(chan)(chan)物(wu)(wu)組(zu)分(fen)氣(qi)體(ti)(ti)液(ye)(ye)(ye)化(hua)的(de)同(tong)時蒸(zheng)發部分(fen),而雜(za)質(zhi)由(you)于(yu)不(bu)(bu)能被液(ye)(ye)(ye)化(hua)或凝(ning)固(gu),當(dang)(dang)通過(guo)有液(ye)(ye)(ye)體(ti)(ti)存在的(de)塔板(ban)時將會(hui)被產(chan)(chan)(chan)物(wu)(wu)組(zu)分(fen)液(ye)(ye)(ye)體(ti)(ti)固(gu)定(ding)下來,產(chan)(chan)(chan)生(sheng)洗(xi)(xi)滌(di)(di)作用(yong),洗(xi)(xi)滌(di)(di)塔就是根據這一原理(li)設計和制造(zao)的(de)。
洗滌塔(ta)由塔(ta)體(ti)、塔(ta)板、再沸器和冷凝器組成(cheng)。在使用過程中再沸器一般
用(yong)(yong)(yong)蒸汽(qi)加熱(re),冷(leng)(leng)凝(ning)器(qi)(qi)用(yong)(yong)(yong)循環水(shui)(shui)導熱(re)。在使(shi)(shi)用(yong)(yong)(yong)前應建立平(ping)衡,即通(tong)入(ru)較純(chun)的產(chan)物組分(fen)(fen)用(yong)(yong)(yong)蒸汽(qi)和冷(leng)(leng)凝(ning)水(shui)(shui)調節其(qi)(qi)蒸發(fa)量(liang)和回流量(liang),使(shi)(shi)其(qi)(qi)能在塔(ta)(ta)板上積(ji)累一(yi)定(ding)厚(hou)度(du)(du)(du)(du)(du)液(ye)(ye)(ye)(ye)體(ti)(ti),當混合(he)(he)氣體(ti)(ti)組分(fen)(fen)通(tong)入(ru)時(shi)(shi)就能迅速(su)起到洗(xi)滌(di)(di)(di)(di)作(zuo)用(yong)(yong)(yong)。在使(shi)(shi)用(yong)(yong)(yong)過(guo)程中(zhong)要(yao)(yao)控(kong)(kong)制好(hao)一(yi)個(ge)(ge)液(ye)(ye)(ye)(ye)位(wei),兩(liang)個(ge)(ge)溫(wen)(wen)(wen)度(du)(du)(du)(du)(du)和兩(liang)個(ge)(ge)壓(ya)(ya)差(cha)等幾個(ge)(ge)要(yao)(yao)點(dian)。即洗(xi)滌(di)(di)(di)(di)塔(ta)(ta)液(ye)(ye)(ye)(ye)位(wei),氣體(ti)(ti)進(jin)(jin)口(kou)溫(wen)(wen)(wen)度(du)(du)(du)(du)(du),塔(ta)(ta)頂溫(wen)(wen)(wen)度(du)(du)(du)(du)(du),塔(ta)(ta)間(jian)壓(ya)(ya)差(cha)(洗(xi)滌(di)(di)(di)(di)塔(ta)(ta)進(jin)(jin)口(kou)壓(ya)(ya)力與塔(ta)(ta)頂壓(ya)(ya)力之(zhi)(zhi)差(cha)),冷(leng)(leng)凝(ning)器(qi)(qi)壓(ya)(ya)差(cha)(塔(ta)(ta)頂與冷(leng)(leng)凝(ning)器(qi)(qi)出(chu)口(kou)壓(ya)(ya)力之(zhi)(zhi)差(cha))。一(yi)般來說,氣體(ti)(ti)進(jin)(jin)口(kou)溫(wen)(wen)(wen)度(du)(du)(du)(du)(du)越高(gao)(gao)越好(hao),可以(yi)防(fang)(fang)止雜(za)質凝(ning)固或(huo)液(ye)(ye)(ye)(ye)化不(bu)(bu)能進(jin)(jin)入(ru)洗(xi)滌(di)(di)(di)(di)塔(ta)(ta),但是也不(bu)(bu)能太高(gao)(gao),以(yi)防(fang)(fang)系統因溫(wen)(wen)(wen)度(du)(du)(du)(du)(du)過(guo)高(gao)(gao)而不(bu)(bu)易(yi)控(kong)(kong)制。控(kong)(kong)制溫(wen)(wen)(wen)度(du)(du)(du)(du)(du)的同時(shi)(shi)還需(xu)保證氣體(ti)(ti)流速(su),即進(jin)(jin)口(kou)的壓(ya)(ya)力不(bu)(bu)能太小,以(yi)便粉塵(chen)能進(jin)(jin)入(ru)洗(xi)滌(di)(di)(di)(di)塔(ta)(ta)。混合(he)(he)氣體(ti)(ti)通(tong)入(ru)洗(xi)滌(di)(di)(di)(di)塔(ta)(ta)后,部分(fen)(fen)氣體(ti)(ti)會冷(leng)(leng)凝(ning)成液(ye)(ye)(ye)(ye)體(ti)(ti)而留(liu)在塔(ta)(ta)釜(fu),調節再沸(fei)器(qi)(qi)的溫(wen)(wen)(wen)度(du)(du)(du)(du)(du)使(shi)(shi)液(ye)(ye)(ye)(ye)體(ti)(ti)向上蒸發(fa),再調節冷(leng)(leng)凝(ning)器(qi)(qi)使(shi)(shi)液(ye)(ye)(ye)(ye)體(ti)(ti)回流至塔(ta)(ta)板,形成一(yi)個(ge)(ge)平(ping)衡。由于(yu)塔(ta)(ta)板上有(you)(you)一(yi)定(ding)厚(hou)度(du)(du)(du)(du)(du)液(ye)(ye)(ye)(ye)體(ti)(ti),所(suo)以(yi)洗(xi)滌(di)(di)(di)(di)塔(ta)(ta)塔(ta)(ta)間(jian)會有(you)(you)一(yi)定(ding)壓(ya)(ya)差(cha),調節再沸(fei)器(qi)(qi)和冷(leng)(leng)凝(ning)器(qi)(qi)時(shi)(shi)應盡量(liang)使(shi)(shi)壓(ya)(ya)差(cha)保持恒定(ding)才能形成一(yi)個(ge)(ge)平(ping)衡。調節塔(ta)(ta)頂溫(wen)(wen)(wen)度(du)(du)(du)(du)(du)時(shi)(shi)應防(fang)(fang)止溫(wen)(wen)(wen)度(du)(du)(du)(du)(du)過(guo)高(gao)(gao)而使(shi)(shi)雜(za)質汽(qi)化或(huo)升華為氣體(ti)(ti)而不(bu)(bu)能起洗(xi)滌(di)(di)(di)(di)作(zuo)用(yong)(yong)(yong),但冷(leng)(leng)凝(ning)溫(wen)(wen)(wen)度(du)(du)(du)(du)(du)也不(bu)(bu)宜(yi)過(guo)低,防(fang)(fang)止產(chan)物液(ye)(ye)(ye)(ye)體(ti)(ti)在冷(leng)(leng)凝(ning)器(qi)(qi)積(ji)液(ye)(ye)(ye)(ye)影響(xiang)使(shi)(shi)用(yong)(yong)(yong)。在注意(yi)以(yi)上要(yao)(yao)點(dian)的同時(shi)(shi)還需(xu)注意(yi)用(yong)(yong)(yong)再沸(fei)器(qi)(qi)調節洗(xi)滌(di)(di)(di)(di)塔(ta)(ta)的液(ye)(ye)(ye)(ye)位(wei),為防(fang)(fang)止塔(ta)(ta)釜(fu)液(ye)(ye)(ye)(ye)中(zhong)雜(za)質濃(nong)度(du)(du)(du)(du)(du)過(guo)高(gao)(gao)產(chan)生沉淀,應使(shi)(shi)其(qi)(qi)緩慢上漲。
1、由于高沸物(wu)在(zai)(zai)洗(xi)(xi)滌過程(cheng)中被固定(ding)在(zai)(zai)洗(xi)(xi)滌塔(ta)(ta)塔(ta)(ta)釜(fu)中,所(suo)以使用(yong)一(yi)段時間后塔(ta)(ta)釜(fu)液的高沸物(wu)含量(liang)會升高,所(suo)以在(zai)(zai)使用(yong)一(yi)定(ding)時間后要(yao)對洗(xi)(xi)滌塔(ta)(ta)塔(ta)(ta)釜(fu)液進行置換(huan),防止高沸物(wu)在(zai)(zai)塔(ta)(ta)釜(fu)沉積(ji)。
2、由于洗(xi)滌塔(ta)塔(ta)釜液中(zhong)含(han)有高沸物(wu),容易(yi)堵塞液位計(ji),所以一般采用(yong)部分回流液沖(chong)洗(xi)液位計(ji)的方式防止液位計(ji)堵塞。
煤(mei)氣化技術都用到這一單元操作。