| 摘要 |
<p>PURPOSE:To easily remove particulate dusts adhered to a filter by a method wherein air is jetted from a plurality of rotary back wash nozzles in an intake valve toward the side wall of the valve together with pressurized water flowing backward from a water distributing basin. CONSTITUTION:At the time of water intake, a bypass valve 20 is closed, filtrate water in a sand-mud filter 2 in the intake valve 1 is sucked by a pump 17 for pumping up water and is fed into the water distributing basin 19 through a suction hose 15 and water feed pipes 16, 18. At the time of removing the dusts adhered to the filter 2, the pump 17 is stopped and the valve 20 is opened, resulting in that water in the basin 19 enters a back washing part 5a of a forked pipe 5, passes through a water guide port 11, a check valve 6 and an orifice 7 and is jetted as pressure water from each back wash nozzle 12 of a nozzle header 10 toward the side wall 4 of the valve 1. The nozzles 12 are curved so that they are rotated by reaction forces of jetting. Simultaneously, the pressure at an outlet of the orifice 7 is reduced so that air is sucked in through an air pipe 8, is mixed into the flowing-back water and is jetted through the nozzles 12 in the form of bubbles to blow away the particulate dusts adhered to the filter 2.</p> |
