為了(le)在(zai)(zai)反沖(chong)(chong)(chong)(chong)(chong)(chong)(chong)洗(xi)(xi)過(guo)(guo)(guo)(guo)程(cheng)中(zhong)(zhong)也能同時(shi)向(xiang)系統供水(shui)(shui)，在(zai)(zai)首部樞紐(niu)往往安裝2個以(yi)上(shang)(shang)過(guo)(guo)(guo)(guo)濾(lv)(lv)罐(guan)(guan)(guan)。如圖(tu)1所示，雙罐(guan)(guan)(guan)反沖(chong)(chong)(chong)(chong)(chong)(chong)(chong)洗(xi)(xi)砂(sha)過(guo)(guo)(guo)(guo)濾(lv)(lv)器的(de)(de)過(guo)(guo)(guo)(guo)濾(lv)(lv)與反沖(chong)(chong)(chong)(chong)(chong)(chong)(chong)洗(xi)(xi)過(guo)(guo)(guo)(guo)程(cheng)是通過(guo)(guo)(guo)(guo)一種(zhong)特制的(de)(de)三向(xiang)閥(fa)門(men)來控制的(de)(de)，當打開三向(xiang)閥(fa)門(men)時(shi)，閥(fa)門(men)向(xiang)后(hou)移(yi)動(dong)封閉(bi)(bi)住反沖(chong)(chong)(chong)(chong)(chong)(chong)(chong)洗(xi)(xi)管進口(kou)而讓壓力水(shui)(shui)流(liu)通過(guo)(guo)(guo)(guo)進水(shui)(shui)管和(he)過(guo)(guo)(guo)(guo)濾(lv)(lv)罐(guan)(guan)(guan)進口(kou)，水(shui)(shui)中(zhong)(zhong)污(wu)(wu)(wu)物(wu)被(bei)(bei)砂(sha)粒之間(jian)(jian)的(de)(de)孔(kong)隙(xi)截留(liu)和(he)浮獲，清(qing)潔的(de)(de)水(shui)(shui)通過(guo)(guo)(guo)(guo)濾(lv)(lv)罐(guan)(guan)(guan)的(de)(de)出(chu)口(kou)和(he)集水(shui)(shui)管進入下(xia)級管道(dao)而送入到(dao)灌(guan)區。反沖(chong)(chong)(chong)(chong)(chong)(chong)(chong)洗(xi)(xi)時(shi)，關閉(bi)(bi)其中(zhong)(zhong)一個過(guo)(guo)(guo)(guo)濾(lv)(lv)罐(guan)(guan)(guan)上(shang)(shang)的(de)(de)三向(xiang)閥(fa)門(men)，同時(shi)也就是打開了(le)該罐(guan)(guan)(guan)的(de)(de)反沖(chong)(chong)(chong)(chong)(chong)(chong)(chong)洗(xi)(xi)管進口(kou)，由另一個過(guo)(guo)(guo)(guo)濾(lv)(lv)罐(guan)(guan)(guan)來的(de)(de)干凈水(shui)(shui)通過(guo)(guo)(guo)(guo)集水(shui)(shui)管進入待沖(chong)(chong)(chong)(chong)(chong)(chong)(chong)洗(xi)(xi)罐(guan)(guan)(guan)內(nei)，水(shui)(shui)流(liu)反向(xiang)流(liu)過(guo)(guo)(guo)(guo)砂(sha)床時(shi)使(shi)(shi)砂(sha)床膨脹向(xiang)上(shang)(shang)，砂(sha)粒之間(jian)(jian)的(de)(de)間(jian)(jian)距增大(da)，被(bei)(bei)截留(liu)在(zai)(zai)孔(kong)隙(xi)之間(jian)(jian)的(de)(de)各種(zhong)污(wu)(wu)(wu)物(wu)被(bei)(bei)水(shui)(shui)沖(chong)(chong)(chong)(chong)(chong)(chong)(chong)動(dong)并帶出(chu)砂(sha)床，經過(guo)(guo)(guo)(guo)反沖(chong)(chong)(chong)(chong)(chong)(chong)(chong)洗(xi)(xi)管排出(chu)罐(guan)(guan)(guan)外，這時(shi)可(ke)以(yi)調節排污(wu)(wu)(wu)管上(shang)(shang)的(de)(de)排污(wu)(wu)(wu)閥(fa)，使(shi)(shi)沖(chong)(chong)(chong)(chong)(chong)(chong)(chong)洗(xi)(xi)水(shui)(shui)流(liu)中(zhong)(zhong)見(jian)不到(dao)過(guo)(guo)(guo)(guo)濾(lv)(lv)砂(sha)流(liu)出(chu)即可(ke)。如果在(zai)(zai)反沖(chong)(chong)(chong)(chong)(chong)(chong)(chong)洗(xi)(xi)時(shi)流(liu)量(liang)(liang)不足(zu)，則可(ke)以(yi)通過(guo)(guo)(guo)(guo)關閉(bi)(bi)裝在(zai)(zai)灌(guan)溉供水(shui)(shui)管上(shang)(shang)的(de)(de)閥(fa)門(men)減少(shao)向(xiang)灌(guan)區的(de)(de)供水(shui)(shui)流(liu)量(liang)(liang)而提高反沖(chong)(chong)(chong)(chong)(chong)(chong)(chong)洗(xi)(xi)流(liu)量(liang)(liang)。每次沖(chong)(chong)(chong)(chong)(chong)(chong)(chong)洗(xi)(xi)時(shi)一定要沖(chong)(chong)(chong)(chong)(chong)(chong)(chong)到(dao)使(shi)(shi)排出(chu)的(de)(de)污(wu)(wu)(wu)水(shui)(shui)變清(qing)為止。

圖1 雙罐反沖洗砂過濾器

1.進(jin)水管 2.排污管 3.反沖洗管 4.三(san)向閥 5.過(guo)濾罐進(jin)口 6.過(guo)濾砂 7.過(guo)濾罐出(chu)口 8.集水管 9.反沖洗管