US5456115A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of counterflow through a pump and method of controlling the operation of a pump in a pumping installation
Assignee: Kansai Electric Power Co Inc
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Filing: 1993-08-04
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Granted: 1995-10-10
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Expires: 2013-08-04
Abstract
Abstract A method of detecting a counterflow in a pump comprises providing with detecting means for detecting variations in the discharge pressure of the pump and signal analyzing means for analyzing oscillation components contained in an output signal from the pressure detecting means, and detecting the pump's operating point to have entered a counterflow characteristic operation region when a waveform of the detection signal generated in association with the variations in the discharge pressure of the pump exhibits a predetermined spectrum distribution. Further, when it is detected that the operating point enters a counterflow characteristic operation region, the escape from that region is performed by temporally throttling the guide vane and temporally increasing the rotating speed.
Inventors
- 👤 Takao Kuwabara
- 👤 Ezo Kita
- 👤 Isao Yokoyama
- 👤 Hiroto Nakagawa
- 👤 Yasuteru Oono
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:00
CPC Classifications
F; F04; F04D; F04D15/00; F04D15/02; F04D15/029; F04B; F04B49/00; F04B49/06; F04B49/065; F04D15/0027; F04D15/0066; F04D15/0088; Y; Y02; Y02E; Y02E10/00; Y02E10/20
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
104 words
A method of detecting a counterflow in a pump, the method comprising the steps of: providing a pressure detecting means for detecting pressure variations in a discharge pressure of the pump; storing a frequency range of a first spectrum which is dominant while the pump is operating in a normal condition; providing signal analyzing means for analyzing said pressure variations to detect a second spectra falling in a predetermined frequency band lower than the frequency range of the first spectrum; and determining that the pump is operating in a counterflow condition when an amplitude of the second spectra is greater than a predetermined level.
Claim 2
Independent Claim
104 words
A method of detecting a counterflow in a pump, the method comprising the steps of: providing a pressure detecting means for detecting pressure variations in a discharge pressure of the pump; storing a frequency range of a first spectrum which is dominant while the pump is operating in a normal condition; providing signal analyzing means for analyzing said pressure variations to detect a second spectra falling in a predetermined frequency band lower than the frequency range of the first spectrum; and determining that the pump is operating in a counterflow condition when an amplitude of the second spectra is greater than a predetermined level.
Claim 3
Independent Claim
100 words
A method of detecting a counterflow in a pump, the method comprising the steps of: providing a detecting means for detecting mechanical vibrations occurring of the pump; storing a frequency range of a first spectrum which is dominant while the pump is operating in a normal condition; providing signal analyzing means for analyzing said mechanical vibrations to detect a second spectra falling in a predetermined frequency band lower than the frequency range in the first spectrum, and determining whether the pump is operating in a counterflow condition when an amplitude of the second spectra is greater than a predetermined level.
Claim 4
Independent Claim
100 words
A method of detecting a counterflow in a pump, the method comprising the steps of: providing a detecting means for detecting mechanical vibrations occurring of the pump; storing a frequency range of a first spectrum which is dominant while the pump is operating in a normal condition; providing signal analyzing means for analyzing said mechanical vibrations to detect a second spectra falling in a predetermined frequency band lower than the frequency range in the first spectrum, and determining whether the pump is operating in a counterflow condition when an amplitude of the second spectra is greater than a predetermined level.
Claim 5
Independent Claim
85 words
A method of detecting counterflow conditions of a pump, the method comprising the steps of: detecting a discharge pressure of the pump; analyzing and evaluating the detected pressure in which an amplitude of spectra of the detected pressure within a predetermined frequency band which is less than the frequency of a dominant spectra in the normal operating condition is compared with a predetermined criteria level; and judging an occurrence of a counterflow if a spectrum exists having an amplitude greater than a predetermined criteria level.
Claim 6
Independent Claim
85 words
A method of detecting counterflow conditions of a pump, the method comprising the steps of: detecting a discharge pressure of the pump; analyzing and evaluating the detected pressure in which an amplitude of spectra of the detected pressure within a predetermined frequency band which is less than the frequency of a dominant spectra in the normal operating condition is compared with a predetermined criteria level; and judging an occurrence of a counterflow if a spectrum exists having an amplitude greater than a predetermined criteria level.
Claim 7
Independent Claim
83 words
A method of detecting counterflow conditions of a pump, the method comprising the steps of: detecting mechanical vibrations of the pump; analyzing and evaluating the mechanical vibrations in which an amplitude of a spectra of the detected vibrations within a predetermined frequency band is less than the frequency of a dominant spectra in normal operating conditions as compared with a predetermined criteria level; and judging an occurrence of a counterflow if there is a spectrum having an amplitude greater than the critical level.
Claim 8
Independent Claim
83 words
A method of detecting counterflow conditions of a pump, the method comprising the steps of: detecting mechanical vibrations of the pump; analyzing and evaluating the mechanical vibrations in which an amplitude of a spectra of the detected vibrations within a predetermined frequency band is less than the frequency of a dominant spectra in normal operating conditions as compared with a predetermined criteria level; and judging an occurrence of a counterflow if there is a spectrum having an amplitude greater than the critical level.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1998-10-09 | 1999-04-10 | 1999-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-10-09 | 2003-04-10 | 2003-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-10-09 | 2007-04-10 | 2007-10-10 | $7700.00 | Window Closed / Lapsed |