US4706492A
Expired / Lapsed
US
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Method and apparatus for determining real gas effects in critical flow nozzles
Assignee: Chevron USA Inc
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Filing: 1986-06-16
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Granted: 1987-11-17
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Expires: 2006-06-16
Abstract
Abstract A method and apparatus for determining the gas flow rate in a high pressure critical flow nozzle is disclosed. A high pressure gas flows through a first critical flow nozzle. Upstream of the first critical flow nozzle a small slip-stream of gas is removed and flows through a smaller second critical flow nozzle. The small second critical flow nozzle drops the pressure of the gas to a low level. This flow rate of this low pressure gas stream is measured in a highly accurate low pressure gas flow rate measuring device. Since the flow rate in this device must be the same as that of the second critical flow nozzle, a correction factor can be calculated for the second critical flow nozzle. This flow rate correction factor will be the same for the first critical flow nozzle.
Inventors
- 👤 Emrys H. Jones, Jr.
- 👤 Robert E. Jackson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:28
CPC Classifications
G; G01; G01F; G01F25/00; G01F25/10; G01F25/15
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
160 words
Apparatus for determining the gas flow rate of a high pressure gas through a critical flow nozzle comprising: a first critical flow nozzle in a high pressure gas flow line; a branch line, said branch line upstream of said first critical flow nozzle, of significantly smaller diameter than said gas flow line, and tubularly connected to said gas flow line; a second critical flow nozzle, said second critical flow nozzle located in said branch line; a low pressure gas flow measuring means, said low pressure gas measuring means downstream of said second critical flow nozzle in said branch line; a first pressure measuring means, said first pressure measuring means located in said gas flow line upstream of said first critical flow nozzle, whereby a pressure within the flow line can be determined; and a first temperature measuring means, said first temperature measuring means located in said gas flow line, whereby a temperature in said gas flow line can be determined.
Claim 2
Dependent Claim
160 words
Apparatus for determining the gas flow rate of a high pressure gas through a critical flow nozzle comprising: a first critical flow nozzle in a high pressure gas flow line; a branch line, said branch line upstream of said first critical flow nozzle, of significantly smaller diameter than said gas flow line, and tubularly connected to said gas flow line; a second critical flow nozzle, said second critical flow nozzle located in said branch line; a low pressure gas flow measuring means, said low pressure gas measuring means downstream of said second critical flow nozzle in said branch line; a first pressure measuring means, said first pressure measuring means located in said gas flow line upstream of said first critical flow nozzle, whereby a pressure within the flow line can be determined; and a first temperature measuring means, said first temperature measuring means located in said gas flow line, whereby a temperature in said gas flow line can be determined.
Claim 3
Dependent Claim
73 words
Apparatus as recited in claim 1 wherein: said low pressure gas flow measuring means is a third critical flow nozzle; a second pressure measuring means is located in said branch line, upstream of said third critical flow nozzle, and downstream of said second critical flow nozzle; and a second temperature measuring means is located in said branch line upstream of said third critical flow nozzle and downstream of said second critical flow nozzle.
Claim 4
Dependent Claim
20 words
Apparatus as recited in claim 1 wherein: said low pressure gas measuring means is an accurate low volume proving meter.
Claim 5
Dependent Claim
133 words
Apparatus for calibrating a gas metering device comprising: a first critical flow nozzle, said critical flow nozzle located in a gas flow line downstream of a meter to be calibrated; a branch line, said branch line downstream of said meter and having a substantially smaller diameter than said gas flow line and tubularly connected to said gas flow line; a second critical flow nozzle, said second critical flow nozzle located in said branch line; a gas flow rate measuring means, said gas flow rate measuring means located in said branch line, downstream of said second critical flow nozzle; a first pressure measuring means located in said flow line, upstream of said first critical flow nozzle; and a first temperature measuring means located in said flow line upstream of said first critical flow nozzle.
Claim 6
Dependent Claim
133 words
Apparatus for calibrating a gas metering device comprising: a first critical flow nozzle, said critical flow nozzle located in a gas flow line downstream of a meter to be calibrated; a branch line, said branch line downstream of said meter and having a substantially smaller diameter than said gas flow line and tubularly connected to said gas flow line; a second critical flow nozzle, said second critical flow nozzle located in said branch line; a gas flow rate measuring means, said gas flow rate measuring means located in said branch line, downstream of said second critical flow nozzle; a first pressure measuring means located in said flow line, upstream of said first critical flow nozzle; and a first temperature measuring means located in said flow line upstream of said first critical flow nozzle.
Claim 7
Dependent Claim
70 words
Apparatus as recited in claim 4 wherein: said gas flow rate measuring means is a third critical flow nozzle; a second pressure measuring means is located in said branch line, downstream of said second critical flow nozzle, upstream of said third critical flow nozzle; and a second temperature measuring means is located in said branch line, downstream of said second critical flow nozzle, upstream of said third critical flow nozzle.
Claim 8
Dependent Claim
17 words
Apparatus as recited in claim 4 wherein: said gas flow rate measuring means is a meter prover.
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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) | 1990-11-16 | 1991-05-18 | 1991-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-16 | 1995-05-18 | 1995-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-16 | 1999-05-18 | 1999-11-17 | $7700.00 | Window Closed / Lapsed |