其一、除塵器布袋清灰系統的壓力范圍

　　除塵(chen)器(qi)布袋清(qing)灰系(xi)統(tong)到(dao)達袋底(di)的壓(ya)(ya)力(li)(li)范圍與除塵(chen)器(qi)上(shang)(shang)壓(ya)(ya)力(li)(li)氣包內(nei)的系(xi)統(tong)供給壓(ya)(ya)力(li)(li)無關。以(yi)澳大利亞高原公司生產的脈(mo)沖(chong)閥(fa)為例：如(ru)果(guo)現場(chang)壓(ya)(ya)力(li)(li)具有0.6MPa，清(qing)潔20條160mm直(zhi)徑，6米長的電(dian)廠除塵(chen)布袋，其噴吹管上(shang)(shang)噴吹孔的口(kou)徑大概(gai)是12-13mm。但如(ru)果(guo)氣包壓(ya)(ya)力(li)(li)只(zhi)有0.2MPa，在(zai)同(tong)(tong)等的工況條件下，同(tong)(tong)樣的脈(mo)沖(chong)閥(fa)只(zhi)能清(qing)灰12-14條同(tong)(tong)尺寸布袋，每(mei)個噴吹孔口(kou)徑大概(gai)需要17-18mm。以(yi)上(shang)(shang)的兩種配(pei)置(zhi)，同(tong)(tong)樣提(ti)供到(dao)達袋底(di)的清(qing)灰壓(ya)(ya)力(li)(li)在(zai)2000-2500Pa之間，達到(dao)清(qing)灰的預期效果(guo)。

　　從本質(zhi)上(shang)分析，袋(dai)(dai)(dai)式除(chu)塵(chen)器的(de)(de)(de)(de)(de)電(dian)廠除(chu)塵(chen)布(bu)(bu)(bu)袋(dai)(dai)(dai)為柔(rou)性(xing)(xing)介質(zhi)，粉塵(chen)層在慣性(xing)(xing)力和反吹氣(qi)(qi)流等作用(yong)(yong)下實(shi)現(xian)清灰。當布(bu)(bu)(bu)袋(dai)(dai)(dai)在膨脹過程中(zhong)，脈(mo)沖(chong)(chong)氣(qi)(qi)流動(dong)能轉(zhuan)化為布(bu)(bu)(bu)袋(dai)(dai)(dai)(含粉塵(chen)層)的(de)(de)(de)(de)(de)慣性(xing)(xing)能和消耗能，對于彈(dan)性(xing)(xing)較(jiao)(jiao)大(da)的(de)(de)(de)(de)(de)布(bu)(bu)(bu)袋(dai)(dai)(dai)，慣性(xing)(xing)能在清灰過程中(zhong)起作用(yong)(yong)，一般較(jiao)(jiao)低的(de)(de)(de)(de)(de)脈(mo)沖(chong)(chong)壓(ya)力和較(jiao)(jiao)小的(de)(de)(de)(de)(de)脈(mo)沖(chong)(chong)氣(qi)(qi)流即可實(shi)現(xian)清灰；對于彈(dan)性(xing)(xing)較(jiao)(jiao)弱的(de)(de)(de)(de)(de)布(bu)(bu)(bu)袋(dai)(dai)(dai)，脈(mo)沖(chong)(chong)氣(qi)(qi)流起作用(yong)(yong)，較(jiao)(jiao)高的(de)(de)(de)(de)(de)脈(mo)沖(chong)(chong)壓(ya)力和較(jiao)(jiao)大(da)的(de)(de)(de)(de)(de)脈(mo)沖(chong)(chong)氣(qi)(qi)流才可實(shi)現(xian)清灰。

　　脈(mo)(mo)(mo)沖(chong)(chong)噴(pen)吹(chui)清(qing)灰裝置(zhi)以壓(ya)(ya)(ya)縮空(kong)氣(qi)(qi)(qi)(qi)作(zuo)為清(qing)灰氣(qi)(qi)(qi)(qi)源，由脈(mo)(mo)(mo)沖(chong)(chong)閥(fa)、氣(qi)(qi)(qi)(qi)包、噴(pen)吹(chui)管(guan)(guan)組(zu)成。每(mei)(mei)排濾袋上方設(she)有(you)(you)噴(pen)吹(chui)管(guan)(guan)，每(mei)(mei)根噴(pen)吹(chui)管(guan)(guan)上設(she)有(you)(you)若(ruo)十(shi)個噴(pen)吹(chui)孔(kong)，每(mei)(mei)個噴(pen)吹(chui)孔(kong)對(dui)準下部濾袋，噴(pen)吹(chui)管(guan)(guan)的(de)(de)(de)一端與氣(qi)(qi)(qi)(qi)包相(xiang)連，氣(qi)(qi)(qi)(qi)包進(jin)入壓(ya)(ya)(ya)縮空(kong)氣(qi)(qi)(qi)(qi)，氣(qi)(qi)(qi)(qi)包上安裝一個淹沒(mei)式脈(mo)(mo)(mo)沖(chong)(chong)閥(fa)(帶電(dian)(dian)磁閥(fa))。電(dian)(dian)磁閥(fa)動(dong)作(zuo)帶動(dong)脈(mo)(mo)(mo)沖(chong)(chong)閥(fa)的(de)(de)(de)膜片作(zuo)短暫動(dong)作(zuo)，氣(qi)(qi)(qi)(qi)包內(nei)(nei)(nei)的(de)(de)(de)壓(ya)(ya)(ya)縮空(kong)氣(qi)(qi)(qi)(qi)經電(dian)(dian)磁脈(mo)(mo)(mo)沖(chong)(chong)閥(fa)瞬間通(tong)過(guo)噴(pen)吹(chui)管(guan)(guan)從小(xiao)孔(kong)噴(pen)入濾袋內(nei)(nei)(nei)，使(shi)濾袋向外膨(peng)脹(zhang)，當袋壁膨(peng)脹(zhang)到位置(zhi)時，很(hen)大(da)的(de)(de)(de)張力使(shi)其受到強烈的(de)(de)(de)沖(chong)(chong)擊(ji)振動(dong)，并獲得較(jiao)大(da)反向加速度從而(er)開始向內(nei)(nei)(nei)收；但(dan)附著在濾袋表面的(de)(de)(de)粉塵(chen)層不受張力作(zuo)用(yong)，由于慣性(xing)力的(de)(de)(de)作(zuo)用(yong)而(er)從濾袋上脫落(luo)，實(shi)現(xian)(xian)濾袋的(de)(de)(de)清(qing)灰。脈(mo)(mo)(mo)沖(chong)(chong)噴(pen)吹(chui)清(qing)灰裝置(zhi)的(de)(de)(de)電(dian)(dian)氣(qi)(qi)(qi)(qi)執(zhi)行(xing)機構(gou)為電(dian)(dian)磁脈(mo)(mo)(mo)沖(chong)(chong)閥(fa)，通(tong)過(guo)控(kong)制(zhi)電(dian)(dian)磁脈(mo)(mo)(mo)沖(chong)(chong)閥(fa)，來達到控(kong)制(zhi)脈(mo)(mo)(mo)沖(chong)(chong)清(qing)灰井然有(you)(you)序進(jin)行(xing)的(de)(de)(de)目的(de)(de)(de)。脈(mo)(mo)(mo)沖(chong)(chong)清(qing)灰系統以電(dian)(dian)磁脈(mo)(mo)(mo)沖(chong)(chong)閥(fa)為控(kong)制(zhi)對(dui)象，采(cai)用(yong)可編程邏輯(ji)控(kong)制(zhi)(PLC)作(zuo)為核心控(kong)制(zhi)，配有(you)(you)壓(ya)(ya)(ya)力/壓(ya)(ya)(ya)差變送器(qi)、鉑(bo)熱電(dian)(dian)阻等檢測(ce)儀(yi)表進(jin)行(xing)信號采(cai)集，在現(xian)(xian)場(chang)設(she)有(you)(you)就地操(cao)作(zuo)箱(xiang)用(yong)于現(xian)(xian)場(chang)調(diao)試、操(cao)作(zuo)，并設(she)有(you)(you)上位機監(jian)(jian)控(kong)系統供用(yong)戶進(jin)行(xing)運(yun)行(xing)監(jian)(jian)控(kong)，整(zheng)套系統功能。

　　其二(er)、袋式除塵器(qi)對細顆粒物PM2.5具有凈化功能(neng)

　　近十年來(lai)，隨著我國經濟發展，大中(zhong)城市頻(pin)發霧霾天氣(qi)，并呈現(xian)越來(lai)越嚴重的(de)趨勢。PM2.5是(shi)造(zao)成霧霾天氣(qi)的(de)罪魁(kui)禍。研究(jiu)表明：在(zai)京(jing)滬等城市的(de)大氣(qi)環(huan)境中(zhong)，15%～20%的(de)PM2.5來(lai)自(zi)燃(ran)煤鍋(guo)(guo)爐集(ji)中(zhong)污染(ran)源。因此(ci)進一步提高電站鍋(guo)(guo)爐煙(yan)氣(qi)的(de)除塵效率，降低(di)排氣(qi)中(zhong)PM2.5的(de)濃度，對改變大氣(qi)環(huan)境具有重要意義(yi)。

　　對于電(dian)站鍋爐(lu)煙氣，電(dian)除(chu)塵(chen)(chen)器對細(xi)顆粒物的捕集能力較弱，排(pai)氣中PM2.5可(ke)占總排(pai)放顆粒物的30%～40%，而袋式除(chu)塵(chen)(chen)器僅(jin)占13%。據清華大學對五家燃煤電(dian)廠(chang)的電(dian)袋復合除(chu)塵(chen)(chen)器排(pai)氣中PM2.5的實測：排(pai)放值僅(jin)為(wei)13.2～2.76mg/Nm3。按對一臺600MW機組計算，袋除(chu)塵(chen)(chen)器可(ke)比(bi)5電(dian)場電(dian)除(chu)塵(chen)(chen)器少排(pai)PM2.5微細(xi)塵(chen)(chen)240t/a。

　　濕式(shi)電除塵(chen)器(qi)確實對微細顆粒物(wu)也具有(you)高(gao)的(de)(de)捕集效率，較近已在多家(jia)電廠試用。但是(shi)對于、多組分的(de)(de)電站鍋爐煙氣，濕式(shi)電除塵(chen)器(qi)并不(bu)具備單獨(du)使用的(de)(de)能(neng)力，通常(chang)只能(neng)作為不(bu)達標除塵(chen)脫(tuo)硫設施下游的(de)(de)末端(duan)“收尾”處理設備配合(he)使用，系統(tong)復雜，占(zhan)地多，二(er)次能(neng)耗大(da)。此(ci)外濕式(shi)除塵(chen)腐蝕、易堵(du)、污染物(wu)轉移、構件易損、維護(hu)管理工作量大(da)的(de)(de)弊端(duan)依然存在。從(cong)總的(de)(de)技術經濟性衡量是(shi)否(fou)合(he)理？能(neng)否(fou)經得起長期穩定運行的(de)(de)考驗？較近已初見端(duan)倪，有(you)待進(jin)一步實踐驗證。