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Title:
BACKFLOW DETECTING SYSTEM WITH ITS DETECTING METHOD FOR GATE PUMP
Document Type and Number:
Japanese Patent JP3965887
Kind Code:
B2
Abstract:

PROBLEM TO BE SOLVED: To provide a backflow detecting system to remove foreign material from a flap valve at a discharge side by detecting the backflow from the dis charge side during shutdown period of a submersible pump.
SOLUTION: In a pump, equipped with a submersible pump in a water shutoff gate 2, provided with a flap valve at discharge side, and forced drainage at closing condition of the water shutoff gate 2, reverse electromotive force generated by the rotation of a rotor 12 or frequency level is detected by the backflow detecting device 18 during the shutdown period of magnetic motor 7 of the submersible pump. This detecting signal is in contrast with the set value of the comparator 19 of control circuit 16 and judged the backflow of the submersible pump and then backflow determination signal is sent to a controller 20 of the control circuit 16. A current circuit 14 connected to the backflow detecting device 18 is switched over the main circuit by the signal of the control controller 20, the magnetic motor 7 is droved at predetermined period and then foreign material in the flap valve is washed out to the discharge side.


Inventors:
Shigeki Ando
Masaki Abe
Application Number:
JP2000269882A
Publication Date:
August 29, 2007
Filing Date:
September 01, 2000
Export Citation:
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Assignee:
Ishigaki Co., Ltd.
International Classes:
E02B7/20; F04D13/08; F04D15/00; F04D15/02; (IPC1-7): F04D13/08; E02B7/20; F04D15/00; F04D15/02
Domestic Patent References:
JP7337080A
JP2000073342A