過(guo)濾式(shi)除塵器(qi)是使含塵氣(qi)體(ti)通過(guo)一定的過(guo)濾材料來達到分離(li)氣(qi)體(ti)中固體(ti)粉塵的一種高效(xiao)除塵設備。過(guo)濾式(shi)除塵器(qi)主要有(you)兩(liang)類(lei)。一類(lei)是利用纖維編織(zhi)物作為(wei)過(guo)濾介質的袋(dai)式(shi)除塵器(qi)；另一類(lei)是采用砂、礫、焦炭等顆粒物作為(wei)過(guo)濾介質的顆粒層(ceng)除塵器(qi)。

袋式除塵器工(gong)作原理

袋式除塵器是將(jiang)棉、毛或人造纖維等材料加工成(cheng)織物作(zuo)為(wei)濾料，制成(cheng)濾袋對含(han)塵氣(qi)體進行(xing)過濾。當含(han)塵氣(qi)流通(tong)過濾料孔隙時粉塵被阻留下來，清潔氣(qi)流穿過濾袋之后排出。沉積在(zai)濾袋上(shang)的粉塵通(tong)過機械振動，從濾料表面(mian)脫落至灰斗中。

濾(lv)(lv)(lv)(lv)料(liao)(liao)本(ben)身的(de)網孔(kong)(kong)較大(da)，一(yi)般為20~50μm，表(biao)面(mian)(mian)起(qi)絨的(de)濾(lv)(lv)(lv)(lv)料(liao)(liao)為5~10μm。因(yin)此，新用濾(lv)(lv)(lv)(lv)袋(dai)的(de)除(chu)(chu)(chu)塵(chen)(chen)(chen)(chen)效率(lv)(lv)較低(di)。粉(fen)(fen)塵(chen)(chen)(chen)(chen)顆粒因(yin)篩(shai)濾(lv)(lv)(lv)(lv)、慣性(xing)碰撞(zhuang)(zhuang)、攔截、擴散、靜電和(he)重力沉降(jiang)(jiang)等作用，使得(de)粗塵(chen)(chen)(chen)(chen)粒首先(xian)被阻(zu)(zu)留(liu)，并在網孔(kong)(kong)之間(jian)產生(sheng) “架橋”現象，很快在濾(lv)(lv)(lv)(lv)布表(biao)面(mian)(mian)形(xing)(xing)成(cheng)(cheng)(cheng)一(yi)層(ceng)(ceng)所謂粉(fen)(fen)塵(chen)(chen)(chen)(chen)初(chu)層(ceng)(ceng)。初(chu)層(ceng)(ceng)形(xing)(xing)成(cheng)(cheng)(cheng)后(hou)，它便(bian)成(cheng)(cheng)(cheng)了(le)濾(lv)(lv)(lv)(lv)袋(dai)的(de)主(zhu)(zhu)要(yao)過(guo)(guo)濾(lv)(lv)(lv)(lv)層(ceng)(ceng)，而濾(lv)(lv)(lv)(lv)布只不過(guo)(guo)起(qi)著(zhu)形(xing)(xing)成(cheng)(cheng)(cheng)顆粒初(chu)層(ceng)(ceng)和(he)支撐它的(de)骨架作用。粉(fen)(fen)塵(chen)(chen)(chen)(chen)初(chu)層(ceng)(ceng)形(xing)(xing)成(cheng)(cheng)(cheng)之后(hou)，使濾(lv)(lv)(lv)(lv)布成(cheng)(cheng)(cheng)為對粗、細粉(fen)(fen)塵(chen)(chen)(chen)(chen)皆有(you)效的(de)過(guo)(guo)濾(lv)(lv)(lv)(lv)材料(liao)(liao)，過(guo)(guo)濾(lv)(lv)(lv)(lv)效率(lv)(lv)劇增。對于1μm以(yi)(yi)(yi)上(shang)(shang)的(de)塵(chen)(chen)(chen)(chen)粒，主(zhu)(zhu)要(yao)靠慣性(xing)碰撞(zhuang)(zhuang)，對于1μm以(yi)(yi)(yi)下(xia)的(de)塵(chen)(chen)(chen)(chen)粒，主(zhu)(zhu)要(yao)靠擴散，總的(de)過(guo)(guo)濾(lv)(lv)(lv)(lv)效率(lv)(lv)可達(da)99%以(yi)(yi)(yi)上(shang)(shang)。隨著(zhu)粉(fen)(fen)塵(chen)(chen)(chen)(chen)在濾(lv)(lv)(lv)(lv)袋(dai)上(shang)(shang)的(de)積聚，除(chu)(chu)(chu)塵(chen)(chen)(chen)(chen)效率(lv)(lv)不斷(duan)增加(jia)，同時(shi)(shi)(shi)阻(zu)(zu)力也相應增大(da)。當阻(zu)(zu)力達(da)到一(yi)定程度(du)時(shi)(shi)(shi)，濾(lv)(lv)(lv)(lv)袋(dai)兩側的(de)壓力差會(hui)把有(you)些已(yi)附著(zhu)在濾(lv)(lv)(lv)(lv)料(liao)(liao)上(shang)(shang)的(de)細小(xiao)粉(fen)(fen)塵(chen)(chen)(chen)(chen)擠壓過(guo)(guo)去，使除(chu)(chu)(chu)塵(chen)(chen)(chen)(chen)效率(lv)(lv)明(ming)顯下(xia)降(jiang)(jiang)，同時(shi)(shi)(shi)除(chu)(chu)(chu)塵(chen)(chen)(chen)(chen)器(qi)阻(zu)(zu)力過(guo)(guo)大(da)會(hui)使除(chu)(chu)(chu)塵(chen)(chen)(chen)(chen)系統的(de)處理氣體量顯著(zhu)下(xia)降(jiang)(jiang)，影響生(sheng)產系統的(de)排(pai)風效果。因(yin)此，除(chu)(chu)(chu)塵(chen)(chen)(chen)(chen)器(qi)阻(zu)(zu)力達(da)到一(yi)定數值后(hou)，要(yao)及時(shi)(shi)(shi)進行清灰(hui)(hui)，而清灰(hui)(hui)時(shi)(shi)(shi)又(you)不能破壞(huai)粉(fen)(fen)塵(chen)(chen)(chen)(chen)初(chu)層(ceng)(ceng)，否則會(hui)引(yin)起(qi)除(chu)(chu)(chu)塵(chen)(chen)(chen)(chen)效率(lv)(lv)顯著(zhu)降(jiang)(jiang)低(di)。