US4087097A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sealing device for the emergent shaft end of a rotating machine
Assignee: Commissariat à l'Énergie Atomique et Aux Énergies Alternatives
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Filing: 1977-02-08
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Granted: 1978-05-02
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Expires: 1997-02-08
Abstract
Abstract The device comprises a first dry seal and an admission chamber for controlled leakage of a neutral barrier gas at a pressure of slightly higher value than the pressure of the hazardous gas which is thus prevented from passing through the seal. The pressure difference across the first seal is maintained at a low and constant value by an external regulator. A second seal closes the admission chamber and is supplied with barrier gas at a pressure of higher value than the pressure of the external atmosphere. Leakage of the barrier gas from the second seal is discharged along with any leakage of hazardous gas through the first seal into an external recovery circuit. The leakage of barrier gas from the admission chamber is into an adjacent compartment defined by the second seal and by a floating ring which produces a pressure drop so as to prevent the external atmosphere from penetrating into the compartment.
Inventors
- 👤 Jacky Bossens
- 👤 Jean Louis Lacourieux
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:47
CPC Classifications
G; G05; G05D; G05D16/00; G05D16/04; G05D16/06; G05D16/063; G05D16/0644; G05D16/0663; F; F16; F16J; F16J15/00; F16J15/16; F16J15/34; F16J15/3404; F16J15/3408; F16J15/3412; F16J15/342; F16J15/40; Y; Y10; Y10S; Y10S277/00; Y10S277/927
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
260 words
A sealing device for preventing leakage of a hazardous gaseous fluid from a casing containing said fluid, said casing comprising a housing for a pump or the like with a rotable shaft from said pump extending through an opening in the casing, the sealing device being located in said opening around the shaft; said device comprising a chamber and a compartment arranged in sequence between the gaseous fluid in the casing and the atmosphere; the chamber comprising a sleeve circumscribing the shaft with first and second means for sealing its ends against the shaft; the compartment being formed by said second sealing means, an annular housing around the shaft and a floating ring contacting the periphery of said shaft; at least two ducts extending through the sleeve, the first duct being in fluid communication with the interior of said chamber for conducting gases away from said chamber, the second duct being for conducting a barrier gas toward said chamber and terminating at its inner end at a sealing face on said sleeve; the second sealing means being biased toward sealing contact with said sealing face, the second sealing means and sealing face being structured to allow the simultaneous flow of the barrier gas from the second duct into the chamber and the compartment; the pressure and volume of barrier gas flow into the compartment being great enough to maintain a pressure drop across the floating ring between the compartment and the atmosphre; and means for regulating a substantially constant pressure differential between the interior of the chamber and the casing.
Claim 2
Dependent Claim
260 words
A sealing device for preventing leakage of a hazardous gaseous fluid from a casing containing said fluid, said casing comprising a housing for a pump or the like with a rotable shaft from said pump extending through an opening in the casing, the sealing device being located in said opening around the shaft; said device comprising a chamber and a compartment arranged in sequence between the gaseous fluid in the casing and the atmosphere; the chamber comprising a sleeve circumscribing the shaft with first and second means for sealing its ends against the shaft; the compartment being formed by said second sealing means, an annular housing around the shaft and a floating ring contacting the periphery of said shaft; at least two ducts extending through the sleeve, the first duct being in fluid communication with the interior of said chamber for conducting gases away from said chamber, the second duct being for conducting a barrier gas toward said chamber and terminating at its inner end at a sealing face on said sleeve; the second sealing means being biased toward sealing contact with said sealing face, the second sealing means and sealing face being structured to allow the simultaneous flow of the barrier gas from the second duct into the chamber and the compartment; the pressure and volume of barrier gas flow into the compartment being great enough to maintain a pressure drop across the floating ring between the compartment and the atmosphre; and means for regulating a substantially constant pressure differential between the interior of the chamber and the casing.
Claim 3
Dependent Claim
77 words
A device according to claim 1, wherein the means for regulating the pressure differential comprises a valve controlled by an elastic diaphragm, said diaphragm being subjected on one face to a pressure which is equal to the pressure of the gaseous fluid within the casing and on the other face to the pressure of the barrier gas within the chamber increased by the difference between the pressures to be maintained on each side of the first seal.
Claim 4
Dependent Claim
148 words
A device according to claim 2, wherein the regulator comprises a second casing divided into two enclosures by a leak-tight elastic diaphragm, one of said enclosures being connected to the pressure of the gaseous fluid and the second enclosure being connected to the chamber, said second enclosure being also in communication through an opening closed by a movable valve with a circuit for the supply of barrier gas at a pressure of higher value than the pressure of the gaseous fluid increased by the pressure difference, said movable valve being rigidly fixed to the leak-tight diaphragm in such a manner as to ensure that the second enclosure is put into communication with the circuit for the supply of barrier gas when the leak-tight diaphragm has moved over a predetermined distance which is a function of the direction and the magnitude of the pressure difference between the two enclosures.
Claim 5
Dependent Claim
39 words
A device according to claim 3, wherein the second enclosure of the regulator is in communication with a low-pressure system for the supply of barrier gas through a second valve which is also rigidly fixed to the leak-tight diaphragm.
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) | 1981-05-01 | 1981-10-31 | 1982-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-01 | 1985-10-31 | 1986-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-01 | 1989-10-31 | 1990-05-02 | $7700.00 | Window Closed / Lapsed |