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Title:
CAVITATION DETECTING DEVICE FOR PUMP
Document Type and Number:
Japanese Patent JPS6445975
Kind Code:
A
Abstract:

PURPOSE: To enhance decision accuracy by spectrally analyzing a pump delivery pressure while comparing a level of low frequency component of the spectral delivery pressure with that when a pump is normal and deciding cavitation to be generated when the deviation of compared result exceeds the reference value.

CONSTITUTION: A pump delivery pressure, when a centrifugal pump 1 is driven by a turbine 2 while opening a delivery valve 3, is detected by a detector 4. Feeding this detection signal to an FFT analyzer 8 through an amplifier 7, spectral analysis is performed in the preset measuring frequency band. Next feeding the analytic result to a cavitation decision means 9, a cavitation decision part 11 calculates a difference between the spectral delivery pressure and that stored in a data memory part 10 in the time of normal operation, and when the difference exceeds a reference value, deciding cavitation to be generated, an instruction of actuating an alarm device 13 while decreasing a speed of the turbine 2 is generated.


Inventors:
NAKAMURA YOSHIAKI
KONDO KIYOSHI
TAKEDA KIYOTAKA
KAWAHARA YASUO
MIYAHARA KIYOSHI
MATSUOKA KIICHI
NAKAMURA NORIZO
FUKUDA SHUNICHI
NAKAZONO HISATOSHI
Application Number:
JP20114487A
Publication Date:
February 20, 1989
Filing Date:
August 12, 1987
Export Citation:
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Assignee:
NIPPON KOKAN KK
JAPAN SHIPBUILDING RES ASS
ISHIKAWAJIMA HARIMA HEAVY IND
MITSUBISHI HEAVY IND LTD
KAWASAKI HEAVY IND LTD
MITSUI SHIPBUILDING ENG
International Classes:
F04B11/00; B65G49/07; (IPC1-7): F04B11/00
Domestic Patent References:
JPS4720701A
JPS5825222A1983-02-15
JPS61244897A1986-10-31
JPS62218661A1987-09-26
JPS5477303A1979-06-20
Attorney, Agent or Firm:
Takehiko Suzue