To easily and precisely measure a drainage volume of a precedence standby type vertical shaft pump including an air and water mixed operation condition.
If a suction water lever TP measured by a water level sensor 11 is higher than an upper side threshold value TPUP which is a water level corresponding to an air supply port 10a, a discharge quantity Q is calculated based on the suction water level TP measured by the water level sensor 11, a discharge water level TE measured by a water level sensor 12, relation of a total pump head and the water discharge quantity in a normal water discharge operation state which is measured in advance and a conduit resistance which is measured in advance. If the water suction level TP is equal to or lower than the upper side threshold value TPUP and higher than a lower side threshold value TPLW which is a predetermined water level higher than the water level of the suction port 5a, the drainage quantity Q is calculated by using relation of the suction water level TP which is measured in advance and the drainage quantity Q. If the water suction level TP is equal to or lower than the lower side threshold value TPLW, the drainage quantity Q is regarded as zero.
| JPH05312179A | 1993-11-22 | |||
| JPH0626899A | 1994-02-04 | |||
| JP2002332983A | 2002-11-22 |
Yasumichi Furukawa
Atsushi Maeda
Yoshiyuki Maebori