JP2003117572A5 - - Google Patents

Description

【００１１】
エアリフトポンプ１２は、濾過床の洗浄時の洗浄排水を排出させるものであり、消費電力が小さく故障が少ないことから好ましく用いられる。エアリフトポンプの吸込口２１は濾過室７の下部又は底部であり、下抑止部材２０よりも下方であればよい。好ましくは、濾過室７の底部の略中央部である。洗浄排水を効果的に（すなわち、残量少なく）引抜くことができるからである。[0011]
The air lift pump 12 is used to discharge the washing drainage at the time of washing the filter bed, and is preferably used because the power consumption is small and the number of failures is small. The suction port 21 of the air lift pump may be the lower portion or the bottom portion of the filtration chamber 7 and may be lower than the lower restraining member 20. Preferably, it is a substantially central portion of the bottom of the filtration chamber 7 . This is because washing drainage can be extracted effectively (that is, the remaining amount is small).

【００１７】
＜（濾過床の）逆洗時＞通常の運転（濾過）を続けるとＳＳは濾過床１０の濾材中に蓄積し、濾過床の濾過抵抗は徐々に大きくなる。これを解消するため濾過床１０を適宜逆洗する（図４（ｂ））。逆洗にあたっては、先ず液の流入を止め、更にブロワ１７からの空気供給を（反応用）散気部材１４から（洗浄用）散気部材９へと切り替える。濾過床１０は撹乱されて（又は流動し）、捕捉されていたＳＳが濾材から剥離する。この際、ブロワ１７からの空気をエアリフトポンプ１２の揚水管内の空気管に吐出させると、その空気は揚水管と空気管との間を上昇し、それに伴って洗浄排水は揚水管の下部から吸引され、空気とともに揚水管上部へ揚水され（エアリフト作用）、好気処理槽１３よりも前段の槽（濾過室７外）へ排出される。濾過室１０内の水位は徐々に下降するとともに、濾過床内の液は濾過床を下向きに流れる。 [0017]
During Backwashing (of Filter Bed) If normal operation (filtration) is continued, SS will accumulate in the filter media of the filter bed 10, and the filtration resistance of the filter bed will gradually increase. In order to eliminate this, the filter bed 10 is appropriately backwashed (FIG. 4 (b)). At the time of backwashing, the inflow of the liquid is first stopped, and the air supply from the blower 17 is switched from the (reaction) diffuser member 14 to the (cleaning) diffuser member 9. The filter bed 10 is disturbed (or flows) and the trapped SS separates from the filter medium. At this time, when the air from the blower 17 is discharged to the air pipe in the pumping pipe of the air lift pump 12, the air rises between the pumping pipe and the air pipe, and the washing drainage is sucked from the lower part of the pumping pipe accordingly. The air is pumped up to the upper part of the pumping pipe (air lift action) together with air and discharged to the tank (outside of the filtration chamber 7) on the front side of the aerobic treatment tank 13. As the water level in the filtration chamber 10 gradually falls, the liquid in the filtration bed flows downward through the filtration bed .

【００１８】
なお、エアリフトポンプ１２は、濾過室７内の水位が下抑止部材２０の下まで下がったときに停止させてもよく、濾過室７内がほぼ空になったところで停止させてもよい。好ましくは、濾過室７内がほぼ空になったところである。また、（洗浄用）散気部材９からの空気の吐出は、濾過室７内の水位が下抑止部材２０を下回ったところで停止させてもよく、エアリフトポンプ１２の停止と合せて停止させてもよい。[0018]
The air lift pump 12 may be stopped when the water level in the filtration chamber 7 falls below the lower restraining member 20, or may be stopped when the inside of the filtration chamber 7 is almost empty. Preferably, the inside of the filtration chamber 7 is almost empty. Further, the discharge of the air from the diffuser member 9 (for cleaning) may be stopped when the water level in the filtration chamber 7 falls below the lower restraining member 20, or may be stopped together with the stop of the air lift pump 12. Good.