US3928004A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of inert gases
Assignee: Air Products and Chemicals Inc
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Filing: 1974-01-07
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Granted: 1975-12-23
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Expires: 1994-01-07
Abstract
Abstract This invention relates to a process for purifying an inert gas and particularly argon. In carrying out the process impure inert gas is passed through a bed of molecular sieve at a temperature approaching the boiling point of the inert gas so that the molecular sieve adsorbs the impurity. The bed is then regenerated by first heating and, thereafter, cooling by passing therethrough a cold stream of pure inert gas until the bed is cooled to an extent which substantially prevents argon adsorption by the molecular sieve. Finally, a stream of cold impure inert gas is reintroduced into the so regenerated bed for reiterating the step for adsorbing the impurity.
Inventors
- 👤 Bernard Ramsay Bligh
- 👤 John Allam
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:21
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/02; B01D53/04; B01D53/0407; B01D53/0423; C; C01; C01B; C01B23/00; F; F25; F25J; F25J3/00; F25J3/02; F25J3/04; F25J3/04642; F25J3/04648; F25J3/04721; F25J3/04733; F25J3/04739; B01D2253/00; B01D2253/10; B01D2256/00; B01D2256/18; B01D2257/00; B01D2257/10; B01D2257/104; B01D2259/00; B01D2259/40; B01D2259/40083; B01D2259/40088; B01D2259/402; F25J2205/00; F25J2205/60; F25J2250/00; F25J2250/30; F25J2250/40; F25J2250/58
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
116 words
A process for purifying an inert gas which includes the following steps: a. passing the impure inert gas through a bed of molecular sieve at a temperature near to the boiling point of the inert gas, such that the molecular sieve adsorbs the impurity; b. regenerating the bed of molecular sieve by heating it; c. cooling the bed of molecular sieve by passing therethrough a cold stream of the pure inert gas at a temperature and rate such that any individual particle of the molecular sieve passes through the temperature range 32*F to -220*F in less than forty minutes; and d. re-introducing a stream of the cold impure inert gas for reiterating the purification step (a).
Claim 2
Dependent Claim
116 words
A process for purifying an inert gas which includes the following steps: a. passing the impure inert gas through a bed of molecular sieve at a temperature near to the boiling point of the inert gas, such that the molecular sieve adsorbs the impurity; b. regenerating the bed of molecular sieve by heating it; c. cooling the bed of molecular sieve by passing therethrough a cold stream of the pure inert gas at a temperature and rate such that any individual particle of the molecular sieve passes through the temperature range 32*F to -220*F in less than forty minutes; and d. re-introducing a stream of the cold impure inert gas for reiterating the purification step (a).
Claim 3
Dependent Claim
68 words
A PROCESS ACCORDING TO CLAIM 1, WHEREIN THE COOLING BED OF MOLECULAR SIEVE IS A COLUMNAR BED AND THE COLD STREAM OF THE PURE INERT GAS IS PASSSED THERETHROUGH SO THAT PARTICLES OF THE MOLECULAR SIEVE IN THE BED ARE PROGRESSIVELY AND SUCCESSIVELY COOLED IN THE DIRECTION IN WHICH THE PURE INERT GAS IS PASSED THROUGH THE BED TO AN EXTENT WHICH SUBSTANTIALLY PREVENTS THE SAID ARGON ADSORPTION.
Claim 4
Dependent Claim
30 words
A process as claimed in claim 1 in which the gas to be purified is selected from the group consisting of argon, krypton and xenon and the impurity is oxygen.
Claim 5
Dependent Claim
31 words
A process as claimed in claim 1 wherein the gas to be purified is argon and the purification step (a) takes place at a temperature in the range -260*F to -300*F.
Claim 6
Dependent Claim
29 words
A process according to claim 1 wherein the impure inert gas is argon and the impurity is oxygen in an amount of less than 3% of the impure gas.
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) | 1978-12-22 | 1979-06-23 | 1979-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-22 | 1983-06-23 | 1983-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-22 | 1987-06-23 | 1987-12-23 | $7700.00 | Window Closed / Lapsed |