采用吸吮式清洗機構的自清洗過濾器在(zai)(zai)(zai)清(qing)(qing)洗(xi)時(shi)可能會出(chu)現因(yin)(yin)濾(lv)(lv)(lv)(lv)(lv)(lv)網(wang)(wang)(wang)局部(bu)長期受變(bian)(bian)(bian)應力(li)(li)(li)的(de)(de)(de)(de)作(zuo)用(yong)，而造成(cheng)(cheng)濾(lv)(lv)(lv)(lv)(lv)(lv)網(wang)(wang)(wang)變(bian)(bian)(bian)形的(de)(de)(de)(de)情(qing)況(kuang)(見圖(tu)1)。吸(xi)(xi)(xi)吮式(shi)自清(qing)(qing)洗(xi)過(guo)濾(lv)(lv)(lv)(lv)(lv)(lv)器(qi)(qi)的(de)(de)(de)(de)清(qing)(qing)洗(xi)是通(tong)過(guo)清(qing)(qing)洗(xi)機(ji)構在(zai)(zai)(zai)過(guo)濾(lv)(lv)(lv)(lv)(lv)(lv)器(qi)(qi)內轉動完成(cheng)(cheng)的(de)(de)(de)(de)；吸(xi)(xi)(xi)吮管(guan)(guan)在(zai)(zai)(zai)經過(guo)濾(lv)(lv)(lv)(lv)(lv)(lv)網(wang)(wang)(wang)表(biao)(biao)面(mian)時(shi)，由于(yu)(yu)吸(xi)(xi)(xi)吮管(guan)(guan)內壓(ya)(ya)力(li)(li)(li)小于(yu)(yu)濾(lv)(lv)(lv)(lv)(lv)(lv)網(wang)(wang)(wang)表(biao)(biao)面(mian)的(de)(de)(de)(de)壓(ya)(ya)力(li)(li)(li)，而使濾(lv)(lv)(lv)(lv)(lv)(lv)網(wang)(wang)(wang)表(biao)(biao)面(mian)的(de)(de)(de)(de)雜質在(zai)(zai)(zai)壓(ya)(ya)差作(zuo)用(yong)下和(he)水流一起(qi)流入排污管(guan)(guan)內而被排出(chu)。在(zai)(zai)(zai)這(zhe)個過(guo)程中，吸(xi)(xi)(xi)吮管(guan)(guan)經過(guo)處的(de)(de)(de)(de)濾(lv)(lv)(lv)(lv)(lv)(lv)網(wang)(wang)(wang)承受向(xiang)(xiang)內的(de)(de)(de)(de)壓(ya)(ya)力(li)(li)(li)P1，該壓(ya)(ya)力(li)(li)(li)與管(guan)(guan)道(dao)(dao)輸(shu)送介質的(de)(de)(de)(de)壓(ya)(ya)力(li)(li)(li)P0大小有(you)直接關(guan)系(xi)：當(dang)管(guan)(guan)道(dao)(dao)輸(shu)送介質的(de)(de)(de)(de)壓(ya)(ya)力(li)(li)(li)越(yue)大，過(guo)濾(lv)(lv)(lv)(lv)(lv)(lv)器(qi)(qi)進行自動清(qing)(qing)洗(xi)時(shi)濾(lv)(lv)(lv)(lv)(lv)(lv)網(wang)(wang)(wang)承受的(de)(de)(de)(de)壓(ya)(ya)力(li)(li)(li)P1也就越(yue)大。由于(yu)(yu)濾(lv)(lv)(lv)(lv)(lv)(lv)網(wang)(wang)(wang)在(zai)(zai)(zai)清(qing)(qing)洗(xi)時(shi)和(he)正(zheng)常(chang)運行時(shi)所承受的(de)(de)(de)(de)壓(ya)(ya)力(li)(li)(li)相(xiang)反，濾(lv)(lv)(lv)(lv)(lv)(lv)網(wang)(wang)(wang)在(zai)(zai)(zai)這(zhe)種不斷變(bian)(bian)(bian)化應力(li)(li)(li)的(de)(de)(de)(de)長期作(zuo)用(yong)下就會發生向(xiang)(xiang)內變(bian)(bian)(bian)形，特(te)別是清(qing)(qing)洗(xi)頻繁的(de)(de)(de)(de)管(guan)(guan)道(dao)(dao)過(guo)濾(lv)(lv)(lv)(lv)(lv)(lv)器(qi)(qi)，因(yin)(yin)此使用(yong)吸(xi)(xi)(xi)吮式(shi)清(qing)(qing)洗(xi)機(ji)構的(de)(de)(de)(de)管(guan)(guan)道(dao)(dao)過(guo)濾(lv)(lv)(lv)(lv)(lv)(lv)器(qi)(qi)要根據(ju)水質要求合理選(xuan)擇濾(lv)(lv)(lv)(lv)(lv)(lv)網(wang)(wang)(wang)的(de)(de)(de)(de)過(guo)濾(lv)(lv)(lv)(lv)(lv)(lv)精(jing)度(du)，還(huan)要考慮(lv)濾(lv)(lv)(lv)(lv)(lv)(lv)網(wang)(wang)(wang)的(de)(de)(de)(de)強度(du)以及工(gong)作(zuo)壓(ya)(ya)力(li)(li)(li)。

圖1濾網變形示意圖

當管道水(shui)流方向(xiang)(xiang)(xiang)突(tu)然(ran)發(fa)生(sheng)變(bian)(bian)化(hua)時，會出(chu)(chu)現(xian)(xian)水(shui)錘現(xian)(xian)象，即水(shui)流快速從反方向(xiang)(xiang)(xiang)流過濾(lv)(lv)(lv)網(wang)，使濾(lv)(lv)(lv)網(wang)承(cheng)受向(xiang)(xiang)(xiang)內的壓(ya)力而發(fa)生(sheng)擠壓(ya)變(bian)(bian)形。為防(fang)止這種情況發(fa)生(sheng)，在過濾(lv)(lv)(lv)器(qi)的出(chu)(chu)水(shui)側安(an)裝了止回閥，當供水(shui)設備出(chu)(chu)現(xian)(xian)問(wen)題，管道水(shui)流方向(xiang)(xiang)(xiang)突(tu)然(ran)發(fa)生(sheng)變(bian)(bian)化(hua)時止回閥可(ke)以立刻關閉(bi)切斷水(shui)流，避免濾(lv)(lv)(lv)網(wang)因承(cheng)受向(xiang)(xiang)(xiang)內的壓(ya)力而發(fa)生(sheng)擠壓(ya)變(bian)(bian)形。