US4455870A
Expired / Lapsed
US
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Method and apparatus for determining liquid flow rates
Assignee: Individual
•
Filing: 1982-06-28
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Granted: 1984-06-26
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Expires: 2002-06-28
Abstract
Abstract There is provided a method of determining the total inflow of a liquid through a liquid-flow system in which the liquid enters a sump cavity and is pumped out of the sump cavity by pump means. Computing means calculates an on-going total inflow volume for the liquid by (i) adding in the sump cavity volume between a lower and upper limit level each time the liquid surface rises to the upper limit level, and (ii) determining the inflow rate over the last portion of the filling time just described and extrapolating this inflow rate over the time when the pump means is pumping to yield an incremental quantity, such quantity being added in to the on-going total inflow volume.
Inventors
- 👤 Johannes N. Jorritsma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:15
CPC Classifications
G; G01; G01F; G01F3/00; G01F3/36; G01F3/38
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
250 words
A method of determining the total inflow of a liquid through a liquid-flow system in which the liquid enters a sump cavity and is pumped out of the sump cavity by pump means, comprising the steps: (a) allowing the liquid surface to rise between a predetermined lower limit level and a predetermined upper limit level while the pump means is shut off, (b) detecting the arrival of the liquid surface at the upper limit level, and signalling the pump means to begin upon such arrival, (c) pumping the liquid out of the sump cavity at a rate faster than the inflow rate, whereby the liquid surface falls between said upper limit level and said lower limit level, (d) detecting the arrival of the liquid surface at the lower limit level, and turning off the pump at such lastmentioned arrival, (e) again allowing the liquid surface to rise as in step (a) and repeating steps (b), (c) and (d) in sequence; (f) calculating an on-going total inflow volume for the liquid by (1) adding in the sump cavity volume between the lower and upper limit levels each time the liquid surface rises to the upper limit level, and (2) determining the inflow rate over a part of the filling time described in (a) above, said part being during the second half of the filling phase, and extrapolating this inflow rate over the time when the pump means is pumping, such extrapolated value being added in to the on-going total inflow volume.
Claim 2
Independent Claim
250 words
A method of determining the total inflow of a liquid through a liquid-flow system in which the liquid enters a sump cavity and is pumped out of the sump cavity by pump means, comprising the steps: (a) allowing the liquid surface to rise between a predetermined lower limit level and a predetermined upper limit level while the pump means is shut off, (b) detecting the arrival of the liquid surface at the upper limit level, and signalling the pump means to begin upon such arrival, (c) pumping the liquid out of the sump cavity at a rate faster than the inflow rate, whereby the liquid surface falls between said upper limit level and said lower limit level, (d) detecting the arrival of the liquid surface at the lower limit level, and turning off the pump at such lastmentioned arrival, (e) again allowing the liquid surface to rise as in step (a) and repeating steps (b), (c) and (d) in sequence; (f) calculating an on-going total inflow volume for the liquid by (1) adding in the sump cavity volume between the lower and upper limit levels each time the liquid surface rises to the upper limit level, and (2) determining the inflow rate over a part of the filling time described in (a) above, said part being during the second half of the filling phase, and extrapolating this inflow rate over the time when the pump means is pumping, such extrapolated value being added in to the on-going total inflow volume.
Claim 3
Dependent Claim
15 words
The method claimed in claim 1, in which the step (f) is carried out electronically.
Claim 4
Dependent Claim
49 words
The method claimed in claim 1, in which the step of determining the inflow rate described in step (f2) is done on an incremental basis, so that, while the pumping means is pumping, an increment of volume can be added in to the ongoing total for successive time increments.
Claim 5
Dependent Claim
27 words
The method claimed in claim 1, in which said part is the last part of the filling phase, and is less than 20% of the filling phase.
Claim 6
Dependent Claim
20 words
The method claimed in claim 4, in which said last part is between 5% and 12% of the filling phase.
Claim 7
Dependent Claim
28 words
The method claimed in claim 1, in which the steps involving detecting the arrival of the liquid surface at various levels are carried out by ultra-sonic detection means.
Claim 8
Dependent Claim
33 words
The method claimed in claim 1, in which the step under (f2) is accomplished by using the arrival of the liquid surface at an intermediate level between the lower and upper limit levels.
Claim 9
Dependent Claim
209 words
Apparatus for determining the inflow rate for liquid entering a sump cavity, comprising: first means for pumping the liquid out of said cavity at a rate faster than the inflow rate, second means for detecting the arrival of the liquid surface at a predetermined upper limit level and for generating a first signal which turns on said first means, third means for detecting the arrival of the liquid surface at a predetermined lower limit level and for generating a second signal which turns off said first means, fourth means for detecting the arrival of the liquid surface at a predetermined intermediate level between the lower and upper limit levels and for generating a third signal, and computing means adapted to calculate an ongoing total inflow volume for the liquid by (1) adding in the sump cavity volume between the lower and upper limit levels each time the liquid surface rises to the upper limit level, and (2) determining the inflow rate over the portion of the filling time during which the liquid surface rises from the intermediate to the upper limit level, and extrapolating this inflow rate over the time when the said first means is pumping, such extrapolated value being added in to the on-going total inflow volume.
Claim 10
Dependent Claim
209 words
Apparatus for determining the inflow rate for liquid entering a sump cavity, comprising: first means for pumping the liquid out of said cavity at a rate faster than the inflow rate, second means for detecting the arrival of the liquid surface at a predetermined upper limit level and for generating a first signal which turns on said first means, third means for detecting the arrival of the liquid surface at a predetermined lower limit level and for generating a second signal which turns off said first means, fourth means for detecting the arrival of the liquid surface at a predetermined intermediate level between the lower and upper limit levels and for generating a third signal, and computing means adapted to calculate an ongoing total inflow volume for the liquid by (1) adding in the sump cavity volume between the lower and upper limit levels each time the liquid surface rises to the upper limit level, and (2) determining the inflow rate over the portion of the filling time during which the liquid surface rises from the intermediate to the upper limit level, and extrapolating this inflow rate over the time when the said first means is pumping, such extrapolated value being added in to the on-going total inflow volume.
Claim 11
Dependent Claim
43 words
Apparatus as claimed in claim 8, in which said computing means calculates the inflow rate on an incremental basis, so that while the first means is pumping, an increment of volume can be added in to the on-going total for successive time increments.
Claim 12
Dependent Claim
38 words
The apparatus claimed in claim 8, in which the volume of the sump cavity between the intermediate and upper limit levels is less than 20% of the volume of the cavity between the lower and upper limit levels.
Claim 13
Dependent Claim
39 words
The apparatus claimed in claim 8, in which the volume of the cavity between the intermediate and upper limit levels is between 5% and 12% of the volume of the cavity between the lower and the upper limit levels.
Claim 14
Dependent Claim
20 words
The apparatus claimed in claim 8, in which each of the second, third and fourth means includes ultra-sonic detection means.
Claim 15
Dependent Claim
59 words
The apparatus claimed in claim 8, in which said first means includes at least one larger and one smaller pump, the apparatus further including control means which selects (a) the smaller pump, (b) the larger pump or (c) both pumps together, to pump liquid out of said cavity depending upon the inflow rate being determined by the computing means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-06-26 | 1987-12-26 | 1988-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-26 | 1991-12-26 | 1992-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-26 | 1995-12-26 | 1996-06-26 | $7700.00 | Window Closed / Lapsed |