在用(yong)多孔(kong)性固(gu)(gu)體(ti)物(wu)質(zhi)(zhi)處理(li)流體(ti)混合(he)物(wu)時,流體(ti)中的某(mou)一(yi)組(zu)分(fen)(fen)或(huo)某(mou)些組(zu)分(fen)(fen)可被吸(xi)(xi)表面并濃集其上,此現(xian)象(xiang)稱(cheng)為(wei)(wei)吸(xi)(xi)附。吸(xi)(xi)附處理(li)廢氣時,吸(xi)(xi)附的對象(xiang)是氣態污染物(wu),氣固(gu)(gu)吸(xi)(xi)附。被吸(xi)(xi)附的氣體(ti)組(zu)分(fen)(fen)稱(cheng)為(wei)(wei)吸(xi)(xi)附質(zhi)(zhi),多孔(kong)固(gu)(gu)體(ti)物(wu)質(zhi)(zhi)稱(cheng)為(wei)(wei)吸(xi)(xi)附劑。
吸(xi)收(shou)法采(cai)用低揮發或不揮發性(xing)溶(rong)劑對VOCs進(jin)行吸(xi)收(shou),再利(li)用VOCs和吸(xi)收(shou)劑物理性(xing)質的差異(yi)進(jin)行分離。
含VOCs的氣(qi)(qi)體(ti)(ti)(ti)(ti)自吸(xi)(xi)(xi)收塔(ta)底部進入塔(ta)內,在上(shang)升過程中(zhong)與來自塔(ta)頂的吸(xi)(xi)(xi)收劑逆流接觸,凈(jing)化后(hou)(hou)的氣(qi)(qi)體(ti)(ti)(ti)(ti)由塔(ta)頂排出。吸(xi)(xi)(xi)收了VOCs的吸(xi)(xi)(xi)收劑通過熱交(jiao)換(huan)器后(hou)(hou),廢(fei)氣(qi)(qi)處理(li)設備(bei)進入汽提塔(ta)頂部,在溫度(du)高于吸(xi)(xi)(xi)收溫度(du)或壓力(li)低于吸(xi)(xi)(xi)收壓力(li)的條件下解吸(xi)(xi)(xi)。解吸(xi)(xi)(xi)后(hou)(hou)的吸(xi)(xi)(xi)收劑經過溶劑冷(leng)凝(ning)器冷(leng)凝(ning)后(hou)(hou)回到吸(xi)(xi)(xi)收塔(ta)。解吸(xi)(xi)(xi)出的VOCs氣(qi)(qi)體(ti)(ti)(ti)(ti)經過冷(leng)凝(ning)器、氣(qi)(qi)液分離器后(hou)(hou)以(yi)較純的VOCs氣(qi)(qi)體(ti)(ti)(ti)(ti)離開汽提塔(ta),被回收利用(yong)。該工藝適(shi)合(he)于VOCs濃度(du)較高、溫度(du)較低的氣(qi)(qi)體(ti)(ti)(ti)(ti)凈(jing)化,其他情(qing)況下需要作相應的工藝調整。
固體表(biao)(biao)面(mian)吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)了(le)吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)質(zhi)后,一(yi)部被吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)的(de)(de)吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)質(zhi)可從吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)劑表(biao)(biao)面(mian)脫離,此現(xian)附(fu)(fu)(fu)(fu)。而(er)(er)當(dang)吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)進行(xing)一(yi)段時間后,由于(yu)表(biao)(biao)面(mian)吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)質(zhi)的(de)(de)濃集,使其吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)能力明(ming)顯(xian)下(xia)降(jiang)而(er)(er)吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)凈化的(de)(de)要(yao)求,此時需(xu)要(yao)采用(yong)一(yi)定的(de)(de)措施(shi)使吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)劑上已(yi)吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)的(de)(de)吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)質(zhi)脫附(fu)(fu)(fu)(fu),以(yi)協的(de)(de)吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)能力,這個過程(cheng)(cheng)(cheng)稱為吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)劑的(de)(de)再生。因此在實際吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)工(gong)程(cheng)(cheng)(cheng)中(zhong),正是(shi)利用(yong)吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)一(yi)再生一(yi)再吸(xi)(xi)(xi)(xi)(xi)附(fu)(fu)(fu)(fu)的(de)(de)循環過程(cheng)(cheng)(cheng),達到除去廢氣中(zhong)污(wu)染(ran)物質(zhi)并回收(shou)廢氣中(zhong)有用(yong)組分。