金屬防塵網具(ju)有不(bu)同形狀和(he)開孔率(lv),蝶形擋(dang)(dang)(dang)風(feng)(feng)(feng)板(ban)(ban)在(zai)一(yi)定的(de)(de)開孔率(lv)下(xia),其具(ju)有明顯降低(di)風(feng)(feng)(feng)速(su)和(he)風(feng)(feng)(feng)力的(de)(de)作(zuo)用。擋(dang)(dang)(dang)風(feng)(feng)(feng)抑塵(chen)(chen)墻的(de)(de)設計當氣流(liu)通(tong)過(guo)每塊擋(dang)(dang)(dang)風(feng)(feng)(feng)抑塵(chen)(chen)板(ban)(ban)時(shi),氣流(liu)將按(an)擋(dang)(dang)(dang)風(feng)(feng)(feng)板(ban)(ban)的(de)(de)開孔通(tong)過(guo)。擋(dang)(dang)(dang)風(feng)(feng)(feng)板(ban)(ban)后面(mian)(mian)出現(xian)分離和(he)附著兩種現(xian)象(xiang)。同時(shi)出現(xian)了(le)上、下(xia)干(gan)擾氣流(liu),降低(di)了(le)來(lai)流(liu)的(de)(de)風(feng)(feng)(feng)速(su),極(ji)大的(de)(de)損失來(lai)流(liu)風(feng)(feng)(feng)的(de)(de)動能(neng)。同時(shi)避免(mian)擋(dang)(dang)(dang)風(feng)(feng)(feng)板(ban)(ban)前風(feng)(feng)(feng)流(liu)的(de)(de)渦(wo)流(liu)、減(jian)(jian)少(shao)來(lai)流(liu)風(feng)(feng)(feng)的(de)(de)湍流(liu)度(du);這樣就(jiu)降低(di)了(le)物料堆表面(mian)(mian)的(de)(de)剪切應力和(he)壓力,從(cong)而減(jian)(jian)少(shao)物料的(de)(de)揚(yang)塵(chen)(chen)。通(tong)過(guo)擋(dang)(dang)(dang)風(feng)(feng)(feng)板(ban)(ban)后的(de)(de)來(lai)流(liu)風(feng)(feng)(feng),出會形成(cheng)湍流(liu)和(he)旋渦(wo)氣流(liu),但此時(shi)的(de)(de)風(feng)(feng)(feng)速(su)、風(feng)(feng)(feng)壓衰減(jian)(jian)幅度(du)很大,是與(yu)風(feng)(feng)(feng)速(su)n次(ci)成(cheng)正(zheng)比。所以風(feng)(feng)(feng)速(su)越大,擋(dang)(dang)(dang)風(feng)(feng)(feng)抑塵(chen)(chen)墻的(de)(de)抑、降塵(chen)(chen)效(xiao)率(lv)越高,控制揚(yang)塵(chen)(chen)的(de)(de)效(xiao)果越佳。
在不同開孔形式下(xia),料(liao)(liao)(liao)堆(dui)表面(mian)(mian)速度由(you)料(liao)(liao)(liao)堆(dui)底部(bu)沿料(liao)(liao)(liao)堆(dui)迎風(feng)面(mian)(mian)表面(mian)(mian)向(xiang)上逐漸增大(da),在料(liao)(liao)(liao)堆(dui)頂(ding)部(bu)出現速度剪切層(ceng),導(dao)致(zhi)背(bei)風(feng)面(mian)(mian)形成速度回流區;料(liao)(liao)(liao)堆(dui)表面(mian)(mian)壓(ya)(ya)力(li)由(you)料(liao)(liao)(liao)堆(dui)底部(bu)沿迎風(feng)面(mian)(mian)表面(mian)(mian)向(xiang)上逐漸減小(xiao),在背(bei)風(feng)面(mian)(mian)則基本(ben)保持不變,圓形開孔防風(feng)網(wang)后物料(liao)(liao)(liao)堆(dui)表面(mian)(mian)的壓(ya)(ya)力(li)較(jiao)低(di),其(qi)抑塵效果(guo)(guo)較(jiao)明顯;湍動(dong)(dong)能(neng)(neng)在物料(liao)(liao)(liao)堆(dui)頂(ding)部(bu)附近較(jiao)大(da),且變化較(jiao)大(da),圓形開孔防風(feng)抑塵網(wang)后料(liao)(liao)(liao)堆(dui)頂(ding)部(bu)湍動(dong)(dong)能(neng)(neng)較(jiao)低(di),其(qi)擋風(feng)效果(guo)(guo)較(jiao)好。