過(guo)濾式除(chu)塵(chen)器(qi)是(shi)使(shi)含塵(chen)氣體(ti)通過(guo)一(yi)定的過(guo)濾材料(liao)來達到分離(li)氣體(ti)中固體(ti)粉塵(chen)的一(yi)種高效(xiao)除(chu)塵(chen)設備。過(guo)濾式除(chu)塵(chen)器(qi)主(zhu)要(yao)有兩類(lei)。一(yi)類(lei)是(shi)利(li)用纖維編織物作(zuo)為過(guo)濾介質的袋式除(chu)塵(chen)器(qi);另一(yi)類(lei)是(shi)采用砂(sha)、礫、焦炭等顆粒物作(zuo)為過(guo)濾介質的顆粒層除(chu)塵(chen)器(qi)。
袋式除塵器工作原理
袋式(shi)除(chu)塵(chen)(chen)(chen)器是將(jiang)棉、毛或人造纖維等(deng)材料(liao)加工成織物(wu)作(zuo)為濾(lv)(lv)(lv)料(liao),制成濾(lv)(lv)(lv)袋對(dui)含(han)塵(chen)(chen)(chen)氣體進行過(guo)濾(lv)(lv)(lv)。當含(han)塵(chen)(chen)(chen)氣流通(tong)過(guo)濾(lv)(lv)(lv)料(liao)孔隙(xi)時粉塵(chen)(chen)(chen)被阻留下(xia)來(lai),清潔氣流穿(chuan)過(guo)濾(lv)(lv)(lv)袋之后排(pai)出。沉積在濾(lv)(lv)(lv)袋上的粉塵(chen)(chen)(chen)通(tong)過(guo)機(ji)械振動,從(cong)濾(lv)(lv)(lv)料(liao)表面脫落至灰(hui)斗中。
濾(lv)(lv)(lv)(lv)(lv)(lv)料本身的(de)(de)網(wang)孔較大(da)(da),一(yi)般(ban)為(wei)20~50μm,表面(mian)(mian)起絨(rong)的(de)(de)濾(lv)(lv)(lv)(lv)(lv)(lv)料為(wei)5~10μm。因(yin)此,新(xin)用濾(lv)(lv)(lv)(lv)(lv)(lv)袋的(de)(de)除(chu)塵(chen)(chen)(chen)(chen)(chen)效(xiao)(xiao)(xiao)率(lv)(lv)較低。粉(fen)(fen)塵(chen)(chen)(chen)(chen)(chen)顆粒因(yin)篩(shai)濾(lv)(lv)(lv)(lv)(lv)(lv)、慣性碰(peng)撞、攔截、擴(kuo)散(san)、靜電和重力(li)沉降(jiang)等作用,使(shi)(shi)得粗(cu)塵(chen)(chen)(chen)(chen)(chen)粒首先被阻(zu)留,并(bing)在網(wang)孔之間產生 “架(jia)橋”現象,很快在濾(lv)(lv)(lv)(lv)(lv)(lv)布(bu)表面(mian)(mian)形(xing)成(cheng)一(yi)層(ceng)(ceng)所謂粉(fen)(fen)塵(chen)(chen)(chen)(chen)(chen)初(chu)(chu)層(ceng)(ceng)。初(chu)(chu)層(ceng)(ceng)形(xing)成(cheng)后(hou)(hou),它便成(cheng)了濾(lv)(lv)(lv)(lv)(lv)(lv)袋的(de)(de)主要過(guo)(guo)濾(lv)(lv)(lv)(lv)(lv)(lv)層(ceng)(ceng),而濾(lv)(lv)(lv)(lv)(lv)(lv)布(bu)只不(bu)過(guo)(guo)起著(zhu)形(xing)成(cheng)顆粒初(chu)(chu)層(ceng)(ceng)和支撐(cheng)它的(de)(de)骨(gu)架(jia)作用。粉(fen)(fen)塵(chen)(chen)(chen)(chen)(chen)初(chu)(chu)層(ceng)(ceng)形(xing)成(cheng)之后(hou)(hou),使(shi)(shi)濾(lv)(lv)(lv)(lv)(lv)(lv)布(bu)成(cheng)為(wei)對(dui)粗(cu)、細粉(fen)(fen)塵(chen)(chen)(chen)(chen)(chen)皆(jie)有(you)效(xiao)(xiao)(xiao)的(de)(de)過(guo)(guo)濾(lv)(lv)(lv)(lv)(lv)(lv)材料,過(guo)(guo)濾(lv)(lv)(lv)(lv)(lv)(lv)效(xiao)(xiao)(xiao)率(lv)(lv)劇增。對(dui)于1μm以(yi)上(shang)(shang)的(de)(de)塵(chen)(chen)(chen)(chen)(chen)粒,主要靠慣性碰(peng)撞,對(dui)于1μm以(yi)下的(de)(de)塵(chen)(chen)(chen)(chen)(chen)粒,主要靠擴(kuo)散(san),總的(de)(de)過(guo)(guo)濾(lv)(lv)(lv)(lv)(lv)(lv)效(xiao)(xiao)(xiao)率(lv)(lv)可(ke)達(da)99%以(yi)上(shang)(shang)。隨著(zhu)粉(fen)(fen)塵(chen)(chen)(chen)(chen)(chen)在濾(lv)(lv)(lv)(lv)(lv)(lv)袋上(shang)(shang)的(de)(de)積聚,除(chu)塵(chen)(chen)(chen)(chen)(chen)效(xiao)(xiao)(xiao)率(lv)(lv)不(bu)斷增加,同(tong)時(shi)阻(zu)力(li)也相應增大(da)(da)。當阻(zu)力(li)達(da)到一(yi)定程度時(shi),濾(lv)(lv)(lv)(lv)(lv)(lv)袋兩側的(de)(de)壓力(li)差(cha)會把有(you)些已附(fu)著(zhu)在濾(lv)(lv)(lv)(lv)(lv)(lv)料上(shang)(shang)的(de)(de)細小粉(fen)(fen)塵(chen)(chen)(chen)(chen)(chen)擠(ji)壓過(guo)(guo)去,使(shi)(shi)除(chu)塵(chen)(chen)(chen)(chen)(chen)效(xiao)(xiao)(xiao)率(lv)(lv)明(ming)顯下降(jiang),同(tong)時(shi)除(chu)塵(chen)(chen)(chen)(chen)(chen)器(qi)阻(zu)力(li)過(guo)(guo)大(da)(da)會使(shi)(shi)除(chu)塵(chen)(chen)(chen)(chen)(chen)系(xi)統的(de)(de)處(chu)理(li)氣體量(liang)顯著(zhu)下降(jiang),影響(xiang)生產系(xi)統的(de)(de)排風效(xiao)(xiao)(xiao)果(guo)。因(yin)此,除(chu)塵(chen)(chen)(chen)(chen)(chen)器(qi)阻(zu)力(li)達(da)到一(yi)定數(shu)值后(hou)(hou),要及時(shi)進行清(qing)灰,而清(qing)灰時(shi)又不(bu)能破(po)壞粉(fen)(fen)塵(chen)(chen)(chen)(chen)(chen)初(chu)(chu)層(ceng)(ceng),否則會引起除(chu)塵(chen)(chen)(chen)(chen)(chen)效(xiao)(xiao)(xiao)率(lv)(lv)顯著(zhu)降(jiang)低。