US4005708A
Expired / Lapsed
US
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Apparatus for endothermal absorption of carbon dioxide
Assignee: Scott Technologies Inc
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Filing: 1975-09-22
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Granted: 1977-02-01
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Expires: 1995-09-22
Abstract
Abstract The absorption of CO2 from gas streams by lithium hydroxide can be caused to proceed at least partially by the reaction LiOH + CO 2 H+402 O LiHCO3 The reaction is endothermal, and more efficient than the normally occurring reaction. The presence of a molecular sieve and water favor the bicarbonate reaction.
Inventors
- 👤 Loyal G. Netteland
- 👤 Clifford E. Heintz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:25
CPC Classifications
A; A62; A62D; A62D9/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
139 words
Apparatus for absorbing carbon dioxide from respiratory gases in a recirculatory breathing apparatus comprising: a. means including a recirculatory gas stream flow path extending from a breathing zone to a carbon dioxide absorption zone and back to said breathing zone; b. means for introducing to said breathing zone carbon dioxide containing respiratory exhalations; c. means for removing from said breathing zone respiratory exhalations; d. means for causing said exhalations to flow in said recirculating gas stream flow; and e. said carbon dioxide absorption zone comprising a first chamber containing lithium hydroxide and downstream immediately thereafter a second chamber containing hydrated molecular sieve containing about 40 to 60 moles, per mole of said sieve, of water, whereby said carbon dioxide is caused to react with said lithium hydroxide at least in part by the reaction: LiOH + CO.sub.2 .sup.H.sbsp.2O LiHCO.sub.3
Claim 2
Dependent Claim
139 words
Apparatus for absorbing carbon dioxide from respiratory gases in a recirculatory breathing apparatus comprising: a. means including a recirculatory gas stream flow path extending from a breathing zone to a carbon dioxide absorption zone and back to said breathing zone; b. means for introducing to said breathing zone carbon dioxide containing respiratory exhalations; c. means for removing from said breathing zone respiratory exhalations; d. means for causing said exhalations to flow in said recirculating gas stream flow; and e. said carbon dioxide absorption zone comprising a first chamber containing lithium hydroxide and downstream immediately thereafter a second chamber containing hydrated molecular sieve containing about 40 to 60 moles, per mole of said sieve, of water, whereby said carbon dioxide is caused to react with said lithium hydroxide at least in part by the reaction: LiOH + CO.sub.2 .sup.H.sbsp.2O LiHCO.sub.3
Claim 3
Dependent Claim
13 words
The apparatus of claim 1 wherein said molecular sieve is a crystalline zeolite.
Claim 4
Dependent Claim
11 words
The apparatus of claim 2 wherein said zeolite is zeolite X.
Claim 5
Dependent Claim
11 words
The apparatus of claim 3 wherein said zeolite is zeolite 13X.
Claim 6
Dependent Claim
23 words
The apparatus of claim 4, wherein said lithium hydroxide and said hydrated molecular sieve are present in relative volume ratio of about 2:1.
Claim 7
Dependent Claim
15 words
The apparatus of claim 1 wherein said gas stream passes through said absorbent medium continuously.
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) | 1980-02-01 | 1980-08-02 | 1981-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-01 | 1984-08-02 | 1985-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-01 | 1988-08-02 | 1989-02-01 | $7700.00 | Window Closed / Lapsed |