US4904158A
Expired / Lapsed
US
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Method and apparatus for cryogenic liquid expansion
Assignee: Praxair Technology Inc
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Filing: 1988-08-18
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Granted: 1990-02-27
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Expires: 2008-08-18
Abstract
Abstract A method and apparatus for work expanding a cryogenic liquid wherein the liquid is expanded in a manner to avoid a transient pressure drop below the flash point thus reducing the potential for cavitation and consequent operating inefficiencies.
Inventors
- 👤 Leslie C. Kun
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:50
CPC Classifications
F; F01; F01D; F01D15/00; F01D15/005; F01D5/00; F01D5/02; F01D5/04; F01D5/043; F01D5/048; F01D5/12; F01D5/14; F01D5/141; F01D5/145; Y; Y10; Y10S; Y10S415/00; Y10S415/914
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
134 words
A method for expanding a cryogenic liquid with reduced cavitation comprising: (a) providing the cryogenic liquid into a turbine comprising a shaft, an impeller mounted on the shaft, and a plurality N of turbine blades mounted on the impeller, N being within the range of from 0.8 to 1.2 times 20 D 0 .25 where D is the outside diameter of the impeller in inches forming N flow channels between the blades; (b) expanding the cryogenic liquid by passing it through the N flow channels between the said plurality of blades thus imparting pressure onto the blades and developing pressure difference across each blade so as to cause rotation of the impeller and shaft; and (c) removing the cryogenic liquid the turbine at a pressure less than its pressure when it entered the turbine.
Claim 2
Independent Claim
134 words
A method for expanding a cryogenic liquid with reduced cavitation comprising: (a) providing the cryogenic liquid into a turbine comprising a shaft, an impeller mounted on the shaft, and a plurality N of turbine blades mounted on the impeller, N being within the range of from 0.8 to 1.2 times 20 D 0 .25 where D is the outside diameter of the impeller in inches forming N flow channels between the blades; (b) expanding the cryogenic liquid by passing it through the N flow channels between the said plurality of blades thus imparting pressure onto the blades and developing pressure difference across each blade so as to cause rotation of the impeller and shaft; and (c) removing the cryogenic liquid the turbine at a pressure less than its pressure when it entered the turbine.
Claim 3
Dependent Claim
12 words
The method of claim 1 wherein the cryogenic liquid is liquid nitrogen.
Claim 4
Dependent Claim
26 words
The method of claim 1 wherein the cryogenic liquid is provided into the turbine at a pressure within the range of from 400 to 1600 psia.
Claim 5
Dependent Claim
26 words
The method of claim 1 wherein the cryogenic liquid is removed from the turbine at a pressure within the range of from 50 to 200 psia.
Claim 6
Dependent Claim
18 words
The method of claim 1 wherein the cryogenic liquid experiences a pressure drop when it exits the turbine.
Claim 7
Dependent Claim
17 words
The method of claim 1 wherein D is within the range of from one to seven inches.
Claim 8
Dependent Claim
17 words
The method of claim 1 wherein at least one of said turbine blades is a partial blade.
Claim 9
Dependent Claim
29 words
The method of claim 7 wherein the turbine blades are mounted on the impeller in alternating fashion so that every full length blade is followed by a partial blade.
Claim 10
Dependent Claim
37 words
The method of claim 7 wherein each partial blade has a length such that the trailing edge of each partial blade is within the range of from 40 to 60 percent of the radius of the impeller.
Claim 11
Dependent Claim
25 words
The method of claim 1 wherein each blade has a thickness within the range of from 0.015 to 0.030 times the radius of the impeller.
Claim 12
Dependent Claim
58 words
An expansion turbine for work expanding a cryogenic liquid with reduced cavitation comprising: a shaft, an impeller mounted on the shaft, and a plurality N of turbine blades mounted on the impeller, N being within the range of from 0.8 to 1.2 times 20 D 0 .25 where D is the outside diameter of the impeller in inches.
Claim 13
Dependent Claim
58 words
An expansion turbine for work expanding a cryogenic liquid with reduced cavitation comprising: a shaft, an impeller mounted on the shaft, and a plurality N of turbine blades mounted on the impeller, N being within the range of from 0.8 to 1.2 times 20 D 0 .25 where D is the outside diameter of the impeller in inches.
Claim 14
Dependent Claim
14 words
The turbine of claim 11 free of any diffuser means attached to its exit.
Claim 15
Dependent Claim
17 words
The turbine of claim 11 wherein D is within the range of from one to seven inches.
Claim 16
Dependent Claim
17 words
The turbine of claim 11 wherein at least one of said turbine blades is a partial blade.
Claim 17
Dependent Claim
29 words
The turbine of claim 14 wherein the turbine blades are mounted on the impeller in alternating fashion so that every full length blade is followed by a partial blade.
Claim 18
Dependent Claim
37 words
The turbine of claim 14 wherein each partial blade has a length such that the trailing edge of each partial blade is within the range of from 40 to 60 percent of the radius of the impeller.
Claim 19
Dependent Claim
25 words
The turbine of claim 11 wherein each blade has a thickness within the range of from 0.015 to 0.030 times the radius of the impeller.
References Cited (Backward Citations)
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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) | 1993-02-26 | 1993-08-28 | 1994-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-02-26 | 1997-08-28 | 1998-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-02-26 | 2001-08-28 | 2002-02-27 | $7700.00 | Window Closed / Lapsed |