US4167102A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Refrigeration system utilizing saturated gaseous refrigerant for defrost purposes
Assignee: JEPSON Corp A CORP OF
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Filing: 1978-01-09
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Granted: 1979-09-11
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Expires: 1998-01-09
Abstract
Abstract A system for refrigerating food products utilizes a saturated gaseous refrigerant, commonly called "cool gas" for defrosting an evaporator or set of evaporators. When defrost is to occur, the saturated gaseous refrigerant flows from a receiver through the evaporator or set thereof being defrosted. A differential pressure control switch operates to prevent flow of refrigerant to the receiver from the liquid supply line through which said refrigerant normally flows from the condenser to the evaporators. The flow from the liquid line to the receiver is prevented whenever the pressure in the liquid line exceeds the pressure in the receiver by a predetermined value. Accordingly, if liquid in the receiver is fully evaporated in providing saturated gaseous refrigerant for defrost purposes, and the pressure in the receiver is less than in the liquid line and causes the flow of liquid from the liquid line to the receiver to be closed off by operation of the differential pressure switch, the defrosting operation switches automatically from cool to hot gas as a response to the depletion of the cool gas supply.
Inventors
- 👤 Benjamin R. Willitts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:23
CPC Classifications
F; F25; F25B; F25B47/00; F25B47/02; F25B47/022; F25B5/00; F25B5/02; F25B2347/00; F25B2347/02; F25B2347/022; F25B2400/00; F25B2400/07; F25B2400/075; F25B2400/22; F25B2700/00; F25B2700/19; F25B2700/193; F25B2700/1933
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
197 words
In a refrigeration system including compressor means having low and high pressure sides, a plurality of evaporators each of which has one end connected to the low side of the compressor means, a refrigerant liquid supply line having an inlet end, said line having a discharge end connected to the other ends of the evaporators, condenser means having an input side connected to the high side of the compressor means and an output side connected to the inlet end of the liquid line, a surge-type receiver, a connecting line extending between the receiver and the liquid line, and a defrost line extending from the receiver to said one end of the evaporators for supplying saturated gaseous refrigerant to the evaporators for defrosting the same, the improvement that comprises defrost control means for permitting flow in both directions through said connecting line in the presence of a predetermined pressure balance as between the receiver and liquid line, and for preventing flow at least in a direction from the liquid line to the receiver, responsive to the appearance therebetween of a pressure imbalance in which the liquid line exceeds, by a predetermined differential value, the pressure within the receiver.
Claim 2
Dependent Claim
197 words
In a refrigeration system including compressor means having low and high pressure sides, a plurality of evaporators each of which has one end connected to the low side of the compressor means, a refrigerant liquid supply line having an inlet end, said line having a discharge end connected to the other ends of the evaporators, condenser means having an input side connected to the high side of the compressor means and an output side connected to the inlet end of the liquid line, a surge-type receiver, a connecting line extending between the receiver and the liquid line, and a defrost line extending from the receiver to said one end of the evaporators for supplying saturated gaseous refrigerant to the evaporators for defrosting the same, the improvement that comprises defrost control means for permitting flow in both directions through said connecting line in the presence of a predetermined pressure balance as between the receiver and liquid line, and for preventing flow at least in a direction from the liquid line to the receiver, responsive to the appearance therebetween of a pressure imbalance in which the liquid line exceeds, by a predetermined differential value, the pressure within the receiver.
Claim 3
Dependent Claim
57 words
In a refrigeration system the improvement of claim 1 wherein said defrost control means includes a main flow control valve in the connecting line arranged to permmit free flow in both directions therethrough in the balanced pressure condition of the receiver and liquid line, and limiting said flow in response to the appearance of said pressure differential.
Claim 4
Dependent Claim
102 words
In a refrigeration system the improvement of claim 1 wherein said defrost control means includes a main flow control valve in the connecting line arranged to permit free flow in both directions therethrough in the balanced pressure condition of the receiver and liquid line, and limiting said flow in response to the appearance of said pressure differential, said defrost control means further including a check valve mounted in the liquid line upstream from the connecting line and arranged to prevent reverse fluid flow within the liquid line through the check valve in a direction toward the output side of the condenser means.
Claim 5
Dependent Claim
98 words
In a refrigeration system the improvement of claim 1 wherein said defrost control means includes a main flow control valve in the connecting line arranged to permit free flow in both directions therethrough in the balanced pressure condition of the receiver and liquid line, and limiting said flow in response to the appearance of said pressure differential, and a check valve connected in by-pass relation to said main flow control valve and mounted to permit free flow only in a direction from the receiver to the liquid line, in the flow-limiting condition of the main flow control valve.
Claim 6
Dependent Claim
108 words
In a refrigeration system the improvement of claim 4, said defrost control means further including a tubular means connected between, and communicating at opposite ends with, the liquid line and the defrost line respectively, a pressure-sensitive switch in the tubular means operable from a normally deactivated position responsive to the appearance of said pressure differential, and circuit means connecting the main flow control valve and said switch with a source of electric power, for actuating the main flow control valve to its flow-limiting position in response to operation of the switch from its normal position when the pressure differential between the receiver and the liquid line is sensed.
Claim 7
Dependent Claim
149 words
In a refrigeration system the improvement of claim 1 wherein said defrost control means includes a main flow control valve in the connecting line arranged to permit free flow in both directions therethrough in the balanced pressure condition of the receiver and liquid line, and limiting said flow in response to the appearance of said pressure differential, said defrost control means further including a receiver pressure control line connected between the high side of the compressor means and the receiver, and a pressure reducing valve in said last-named line effective to maintain the receiver pressure at a value that is less than that at the high side of the compressor means, and that is selected to produce flow of hot gas from said high side to and through the receiver into the defrost line in response to the depletion, within the receiver, of the supply of saturated gaseous refrigerant.
Claim 8
Dependent Claim
50 words
In a refrigeration system the improvement of claim 6 wherein said pressure reducing valve is arranged to maintain a predetermined difference in pressures between said high side of two compressor means and the receiver such that the receiver pressure follows, but does not fall below, that in this liquid line.
Claim 9
Dependent Claim
97 words
In a refrigeration system the improvement of claim 1, further including a receiver pressure control line connected between the high side of the compressor means and the receiver, and a pressure reducing valve in said control line adapted to maintain the pressure in the receiver at a value that is less than that at the high side of the compressor means and is selected to produce flow of hot gas from said high side through the receiver and into the defrost line for defrost purposes upon depletion, within the receiver, of the supply of saturated gaseous refrigerment.
Claim 10
Dependent Claim
76 words
In a refrigeration system the improvement of claim 8 in which said last-named valve comprises a differential pressure regulating valve adapted to maintain a predetermined pressure at the high side of the compressor means and in the receiver respectively, the receiver pressure being selected to be less than that at the high side by a predetermined extent and to remain less by said extent during pressure fluctuations occurring within the high side of the refrigeration system.
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) | 1982-09-10 | 1983-03-12 | 1983-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-09-10 | 1987-03-12 | 1987-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-09-10 | 1991-03-12 | 1991-09-11 | $7700.00 | Window Closed / Lapsed |