Patent US4900225A successfully refreshed from Google Patents.
US4900225A
Expired / Lapsed
US
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Centrifugal compressor having hybrid diffuser and excess area diffusing volute
Assignee: Praxair Technology Inc
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Filing: 1989-03-08
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Granted: 1990-02-13
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Expires: 2009-03-08
Abstract
Abstract A centrifugal compressor having a two section diffuser which has a tapered section having a constant diffusing area along its radial length, and a straight section having an increasing diffusing area along its radial length, and a diffusing volute having a throat area significantly larger than conventional designs.
Inventors
- 👤 James B. Wulf
- 👤 Timothy D. Craig
- 👤 Alfred P. Evans
- 👤 Ross H. Sentz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:54
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/40; F04D29/42; F04D29/44; F04D29/441; F05; F05D; F05D2250/00; F05D2250/50; F05D2250/52
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
111 words
A centrifugal compressor comprising: (A) a rotatable shaft; (B) an impeller wheel mounted on the shaft; (C) a diffuser extending radially from a diffuser entrance at the impeller wheel to a diffuser exit at a volute, said diffuser having a tapered section extending from the diffuser entrance to an intermediate point and a straight section extending from the intermediate point to the diffuser exit, said tapered section having a constant diffusing area along its radial length and said straight section having an increasing diffusing area along its radial length; and (D) a volute throat area within the range of from 70 to 90 percent of the area of the diffuser exit.
Claim 2
Dependent Claim
111 words
A centrifugal compressor comprising: (A) a rotatable shaft; (B) an impeller wheel mounted on the shaft; (C) a diffuser extending radially from a diffuser entrance at the impeller wheel to a diffuser exit at a volute, said diffuser having a tapered section extending from the diffuser entrance to an intermediate point and a straight section extending from the intermediate point to the diffuser exit, said tapered section having a constant diffusing area along its radial length and said straight section having an increasing diffusing area along its radial length; and (D) a volute throat area within the range of from 70 to 90 percent of the area of the diffuser exit.
Claim 3
Dependent Claim
29 words
The centrifugal compressor of claim 1 wherein the diffuser has a total radial length with the range of from 0.8 to 1.2 times the radius of the impeller wheel.
Claim 4
Dependent Claim
25 words
The centrifugal compressor of claim 1 wherein the diffuser straight section comprises from 20 to 50 percent of the total radial length of the diffuser.
Claim 5
Dependent Claim
21 words
The centrifugal compressor of claim 1 wherein the diffuser has a pinch ratio within the range of from 0.30 to 0.50.
Claim 6
Dependent Claim
16 words
The centrifugal compressor of claim 1 wherein the diffuser has a pinch ratio of about 0.40.
Claim 7
Dependent Claim
29 words
The centrifugal compressor of claim 1 wherein the volute has a throat area within the range of from 75 to 85 percent of the area of the diffuser exit.
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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) | 1993-02-12 | 1993-08-14 | 1994-02-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-02-12 | 1997-08-14 | 1998-02-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-02-12 | 2001-08-14 | 2002-02-13 | $7700.00 | Window Closed / Lapsed |