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US3848422A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Refrigeration plants
Assignee: Svenska Rotor Maskiner AB
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Filing: 1974-01-23
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Granted: 1974-11-19
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Expires: 1994-01-23
Abstract
Abstract Refrigeration plant comprising two stage compression. The low pressure compressor or booster is of the screw compressor type running at high speed with respect to the high pressure compressor and provided with oil injection, restricted to the amount necessary for lubrication of the contact surfaces of the rotors.
Inventors
- 👤 L Schibbye
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:48
CPC Classifications
F; F04; F04C; F04C29/00; F04C29/0007; F04B; F04B39/00; F04B39/06; F04B39/062; F04C23/00; F25; F25B; F25B1/00; F25B1/04; F25B1/047; F25B1/10; F25B2400/00; F25B2400/13; F25B2400/23; Y; Y10; Y10S; Y10S418/00; Y10S418/01
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
131 words
A method of operating a refrigeration plant including a condenser, an evaporator, a first compressor means forming a low pressure stage and a second compressor means forming a high pressure stage each said compressor means being of the meshing screw rotor type having a first rotor driven by a prime mover and a second rotor driven by direct contact between its lands and the lands of the first rotor, comprising the steps of driving the first compressor means with a speed such that the peripheral velocity of its male rotor is higher than that of the male rotor of the second compressor means and supplying lubricating oil to the first compressor means in an amount at least not considerably exceeding what is necessary to satisfactorily lubricate the relatively movable contact surfaces.
Claim 2
Independent Claim
131 words
A method of operating a refrigeration plant including a condenser, an evaporator, a first compressor means forming a low pressure stage and a second compressor means forming a high pressure stage each said compressor means being of the meshing screw rotor type having a first rotor driven by a prime mover and a second rotor driven by direct contact between its lands and the lands of the first rotor, comprising the steps of driving the first compressor means with a speed such that the peripheral velocity of its male rotor is higher than that of the male rotor of the second compressor means and supplying lubricating oil to the first compressor means in an amount at least not considerably exceeding what is necessary to satisfactorily lubricate the relatively movable contact surfaces.
Claim 3
Dependent Claim
69 words
A method as defined in claim 1 and further comprising the steps of drawing off liquid refrigerant from the high pressure section of the plant and injecting said liquid refrigerant into the grooves of the rotors of the first compressor means at such a stage of the compression and at a rate such that the temperature of the gaseous refrigerant is prevented from rising above a desired discharge temperature.
Claim 4
Dependent Claim
44 words
A method as defined in claim 1, characterized in that the first compressor means is driven at a speed such that the peripheral velocity of its male rotor is at least about two times that of the male rotor of the second compressor means.
Claim 5
Dependent Claim
44 words
A method as defined in claim 2, characterized in that the first compressor means is driven at a speed such that the peripheral velocity of its male rotor is at least about two times that of the male rotor of the second compressor means.
Claim 6
Dependent Claim
67 words
A method as defined in claim 2, characterized in that said liquid reFrigerant injected into the grooves of the rotors of the first compressor means is drawn off from said condenser and injected into the working chamber at a location leading to an introduction of the liquid refrigerant into the working chamber when the pressure in said working chamber has reached the discharge pressure of the compressor.
Claim 7
Dependent Claim
43 words
Method as defined in claim 1 wherein the step for supplying lubricating oil to the first compressor means (10A) comprises: supplying lubricating oil in an amount to provide only a film of oil on the relative mating surfaces of the first compressor means.
Claim 8
Dependent Claim
55 words
Method as defined in claim 1 wherein the step for supplying lubricating oil to the first compressor means (10A) comprises: supplying lubricating oil in an amount sufficient to provide a lubricating coating film of oil on the relative mating surfaces of the first compressor means, but not in substantial excess for such a coating film.
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) | 1977-11-18 | 1978-05-20 | 1978-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-18 | 1982-05-20 | 1982-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-18 | 1986-05-20 | 1986-11-19 | $7700.00 | Window Closed / Lapsed |