| 摘要 |
PURPOSE:To satisfy a specified pump capacity without doubling the number of pumps being installed and to prevent complication of a control system by a method wherein a speed variable type pump having dimension high enough to allow containing of it in the bore of a tunnel and besides alignment of pumps in a level is suppressed to a single row like a conventional method. CONSTITUTION:A plurality of speed variable type P pump units 9 in the vicinity of a facing 3, being capable of being contained in an empty region in a tunnel having a given inside diameter, are connected in parallel to a discharge line 8 according to necessary discharge lift capacity and arranged in a single row. Or, a plurality of speed variable type pump units 10 capable of being contained in an empty region on a tunnel 12 having a given inside diameter are connected in parallel to a plurality of constant speed pumps for relay and arranged in a single row in the level. Or, a bypass circuit bypassing the constant speed pump unit for a relay is arranged in the constant speed pump unit 10 for relay. |
