To prevent both of delay in start of drainage and hunting operation, in a drainage pump installed to a suction water tank in which water flowing over a mount flows from the upstream.
Pumps 4A-4E are installed to the suction water tank 5 in which the water flows over the mount 9 from the upstream, and drainage starting water levels of the pumps 4A-4E are set. An overflow height H that is a height from an upper end of the mount 9 to a level of overflowing water is acquired so that an overflow water quantity q of a flow rate of water flowing over the mount 9 and flowing in the suction water tank 5 satisfies an expression of Q≤q<1.05Q, with respect to a drainage water quantity Q of the pumps 4A-4E. A water level of a pump well 2 including the mount 9 and the suction water tank 5 corresponding to the overflow height H is set to be the drainage starting water level WLs1 of the pump 4A firstly starting drainage.
| JPH06193584A | 1994-07-12 | |||
| JPH0544683A | 1993-02-23 | |||
| JPH05180169A | 1993-07-20 |
Mitsuo Tanaka
Atsushi Maeda
Yoshiyuki Maebori