在用多(duo)孔性固(gu)體(ti)(ti)物質處理流(liu)體(ti)(ti)混合(he)物時,流(liu)體(ti)(ti)中的某一組分(fen)或(huo)某些組分(fen)可被吸(xi)(xi)(xi)(xi)(xi)表面并濃集其上,此現象(xiang)稱(cheng)為(wei)吸(xi)(xi)(xi)(xi)(xi)附。吸(xi)(xi)(xi)(xi)(xi)附處理廢氣時,吸(xi)(xi)(xi)(xi)(xi)附的對象(xiang)是氣態污(wu)染物,氣固(gu)吸(xi)(xi)(xi)(xi)(xi)附。被吸(xi)(xi)(xi)(xi)(xi)附的氣體(ti)(ti)組分(fen)稱(cheng)為(wei)吸(xi)(xi)(xi)(xi)(xi)附質,多(duo)孔固(gu)體(ti)(ti)物質稱(cheng)為(wei)吸(xi)(xi)(xi)(xi)(xi)附劑。
吸收(shou)法采(cai)用(yong)低揮發或不揮發性(xing)溶劑(ji)對(dui)VOCs進行(xing)吸收(shou),再利用(yong)VOCs和吸收(shou)劑(ji)物理性(xing)質的差異進行(xing)分離。
含VOCs的(de)氣體(ti)(ti)自吸(xi)(xi)(xi)(xi)(xi)收(shou)(shou)塔(ta)底部進入(ru)塔(ta)內(nei),在上(shang)升過程中與來自塔(ta)頂(ding)(ding)的(de)吸(xi)(xi)(xi)(xi)(xi)收(shou)(shou)劑(ji)逆流接觸,凈(jing)化后的(de)氣體(ti)(ti)由塔(ta)頂(ding)(ding)排出。吸(xi)(xi)(xi)(xi)(xi)收(shou)(shou)了VOCs的(de)吸(xi)(xi)(xi)(xi)(xi)收(shou)(shou)劑(ji)通(tong)過熱(re)交換器(qi)(qi)(qi)后,廢(fei)氣處理設備(bei)進入(ru)汽提塔(ta)頂(ding)(ding)部,在溫(wen)度(du)高于吸(xi)(xi)(xi)(xi)(xi)收(shou)(shou)溫(wen)度(du)或壓力低于吸(xi)(xi)(xi)(xi)(xi)收(shou)(shou)壓力的(de)條件下解(jie)吸(xi)(xi)(xi)(xi)(xi)。解(jie)吸(xi)(xi)(xi)(xi)(xi)后的(de)吸(xi)(xi)(xi)(xi)(xi)收(shou)(shou)劑(ji)經過溶(rong)劑(ji)冷凝(ning)器(qi)(qi)(qi)冷凝(ning)后回(hui)到吸(xi)(xi)(xi)(xi)(xi)收(shou)(shou)塔(ta)。解(jie)吸(xi)(xi)(xi)(xi)(xi)出的(de)VOCs氣體(ti)(ti)經過冷凝(ning)器(qi)(qi)(qi)、氣液(ye)分(fen)離器(qi)(qi)(qi)后以(yi)較(jiao)(jiao)純(chun)的(de)VOCs氣體(ti)(ti)離開汽提塔(ta),被(bei)回(hui)收(shou)(shou)利用。該工(gong)藝(yi)適合于VOCs濃度(du)較(jiao)(jiao)高、溫(wen)度(du)較(jiao)(jiao)低的(de)氣體(ti)(ti)凈(jing)化,其他情況下需要作相應的(de)工(gong)藝(yi)調整。
固體表(biao)(biao)面吸(xi)(xi)(xi)附(fu)(fu)(fu)了吸(xi)(xi)(xi)附(fu)(fu)(fu)質(zhi)后,一(yi)(yi)部被(bei)吸(xi)(xi)(xi)附(fu)(fu)(fu)的(de)吸(xi)(xi)(xi)附(fu)(fu)(fu)質(zhi)可從吸(xi)(xi)(xi)附(fu)(fu)(fu)劑表(biao)(biao)面脫離(li),此(ci)現附(fu)(fu)(fu)。而(er)當吸(xi)(xi)(xi)附(fu)(fu)(fu)進(jin)行一(yi)(yi)段(duan)時間后,由于表(biao)(biao)面吸(xi)(xi)(xi)附(fu)(fu)(fu)質(zhi)的(de)濃集,使其吸(xi)(xi)(xi)附(fu)(fu)(fu)能(neng)力(li)(li)明(ming)顯(xian)下降而(er)吸(xi)(xi)(xi)附(fu)(fu)(fu)凈化的(de)要求,此(ci)時需要采用(yong)(yong)一(yi)(yi)定(ding)的(de)措施使吸(xi)(xi)(xi)附(fu)(fu)(fu)劑上已吸(xi)(xi)(xi)附(fu)(fu)(fu)的(de)吸(xi)(xi)(xi)附(fu)(fu)(fu)質(zhi)脫附(fu)(fu)(fu),以協的(de)吸(xi)(xi)(xi)附(fu)(fu)(fu)能(neng)力(li)(li),這個過程(cheng)稱為吸(xi)(xi)(xi)附(fu)(fu)(fu)劑的(de)再生。因此(ci)在實際吸(xi)(xi)(xi)附(fu)(fu)(fu)工程(cheng)中,正是利用(yong)(yong)吸(xi)(xi)(xi)附(fu)(fu)(fu)一(yi)(yi)再生一(yi)(yi)再吸(xi)(xi)(xi)附(fu)(fu)(fu)的(de)循環過程(cheng),達(da)到除(chu)去(qu)廢(fei)氣中污(wu)染(ran)物質(zhi)并回收(shou)廢(fei)氣中有用(yong)(yong)組分(fen)。