US4705459A
Expired / Lapsed
US
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Method of observing the pumping characteristics of a positive displacement pump
Assignee: Schlumberger Technology Corp
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Filing: 1985-08-19
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Granted: 1987-11-10
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Expires: 2005-08-19
Abstract
Abstract The invention relates in particular to measuring the delivery rate of a positive displacement pump comprising at least one piston (3) driven with reciprocating movement in a chamber (2), which chamber is connected to an inlet circuit (4) via an inlet valve (5) and to an outlet circuit (6) via a delivery valve (7). The number of cycles performed by the pump in unit time are counted, and simultaneously its volumetric efficiency is measured, thereby enabling its real delivery rate to be deduced. Its volumetric efficiency may be measured by means of position sensors (17, 18) detecting the closure and opening instants of the delivery valve, with another sensor determining the instants at which the piston (3) passes through its end positions.
Inventors
- 👤 Paul H. Buisine
- 👤 Paul Dancer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:05
CPC Classifications
F; F04; F04B; F04B51/00; F04B2201/00; F04B2201/02; F04B2201/0201; F04B2201/0207; F04B2201/06; F04B2201/0601; Y; Y10; Y10T; Y10T137/00; Y10T137/8158; Y10T137/8225; Y10T137/8242
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
186 words
A method determining the flow rate delivered by a positive displacement pump in operation, the pump having at least one piston driven with a reciprocating motion in a chamber, which chamber is connected to a feed circuit for fluid to be pumped via an inlet valve and to an outlet circuit via a delivery valve, said valves being mechanically independent of the piston, the method comprising: (a) counting the number of cycles performed by the pump in unit time; (b) determining a corrected volume of the pump by: (i) measuring the partial volumes of the chamber swept by the piston between an instant at which the piston passes through its end position of maximum engagement in the chamber and a closure instant of the delivery valve, and also between an instant at which the piston passes through its opposite end position and an opening instant of the delivery valve; (ii) subtracting the two partial volumes from the volume swept by the piston; and (c) multiplying the number of cycles per unit time by the corrected volume of the pump so as to provide the flow rate.
Claim 2
Independent Claim
186 words
A method determining the flow rate delivered by a positive displacement pump in operation, the pump having at least one piston driven with a reciprocating motion in a chamber, which chamber is connected to a feed circuit for fluid to be pumped via an inlet valve and to an outlet circuit via a delivery valve, said valves being mechanically independent of the piston, the method comprising: (a) counting the number of cycles performed by the pump in unit time; (b) determining a corrected volume of the pump by: (i) measuring the partial volumes of the chamber swept by the piston between an instant at which the piston passes through its end position of maximum engagement in the chamber and a closure instant of the delivery valve, and also between an instant at which the piston passes through its opposite end position and an opening instant of the delivery valve; (ii) subtracting the two partial volumes from the volume swept by the piston; and (c) multiplying the number of cycles per unit time by the corrected volume of the pump so as to provide the flow rate.
Claim 3
Dependent Claim
37 words
A method according to claim 1, characterized by the fact that the instants at which the piston passes through its end positions are determined by measuring the varying position of the piston as a function of time.
Claim 4
Dependent Claim
39 words
A method according to claim 1, characterized by the fact that the instants at which the piston passes through its end positions are determined as being equidistant between the consecutive instants at which the piston passes a predetermined position.
Claim 5
Dependent Claim
34 words
A method according to claim 1 characterized by the fact that the closure instants of the delivery valve are determined by detecting the shocks produced by the valve closing against a delivery valve seat.
Claim 6
Dependent Claim
38 words
A method according to claim 1 characterized by the fact that the closure and/or opening instants of the delivery valve are determined by accoustically detecting the noise of fluid escaping between the valve and a delivery valve seat.
Claim 7
Dependent Claim
39 words
A method according to claim 1 characterized by the fact that the closure and/or opening instants of the delivery valve are determined by measuring their positions which vary as a function of time relative to a delivery valve seat.
Claim 8
Dependent Claim
37 words
A method according to claim 1 characterized by the fact that the closure and/or opening instants of the delivery valve are determined by measuring the internal pressure in the chamber which varies as a function of time.
Claim 9
Independent Claim
193 words
A method of determining the flow rate delivered by a positive displacement pump in operation, the pump having at least one piston driven with a reciprocating motion in a chamber, which chamber is connected to a feed circuit for fluid to be pumped via an inlet valve and to an outlet circuit via a delivery valve, said valves being mechanically independent of the piston, the method comprising: (a) counting the number of cycles performed by the pump in unit time; (b) determining a corrected volume of the pump, by: (i) sensing the position of the piston and at least one of the valves as a function of time, and determining at least the time differences between the instant at which at least one of the valves closes and/or opens and the passages of the piston through its end positions; (ii) ascertaining from the time differences, partial volumes of the chamber swept by the piston during such time differences; and (iii) subtracting the partial volumes from the volume of the chamber; (c) multiplying the number of cycles per unit time by the corrected volume of the pump so as to provide the flow rate.
Claim 10
Independent Claim
193 words
A method of determining the flow rate delivered by a positive displacement pump in operation, the pump having at least one piston driven with a reciprocating motion in a chamber, which chamber is connected to a feed circuit for fluid to be pumped via an inlet valve and to an outlet circuit via a delivery valve, said valves being mechanically independent of the piston, the method comprising: (a) counting the number of cycles performed by the pump in unit time; (b) determining a corrected volume of the pump, by: (i) sensing the position of the piston and at least one of the valves as a function of time, and determining at least the time differences between the instant at which at least one of the valves closes and/or opens and the passages of the piston through its end positions; (ii) ascertaining from the time differences, partial volumes of the chamber swept by the piston during such time differences; and (iii) subtracting the partial volumes from the volume of the chamber; (c) multiplying the number of cycles per unit time by the corrected volume of the pump so as to provide the flow rate.
Claim 11
Dependent Claim
42 words
A method according to claim 8 characterized by the fact that the closure and/or opening instants of the valve are determined by measuring the pressure in the inlet and/or outlet circuits and/or in the chamber which vary as a function of time.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-11-09 | 1991-05-11 | 1991-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-09 | 1995-05-11 | 1995-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-09 | 1999-05-11 | 1999-11-10 | $7700.00 | Window Closed / Lapsed |