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US3735603A Expired / Lapsed US ⏱️ 0.0 years remaining

Liquid refrigerant feed control

Assignee: MARSHALL INDUSTRIES Inc
•
Filing: 1971-08-12
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Granted: 1973-05-29
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Expires: 1991-08-12
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Abstract

Abstract The quality of the suction gas at the input of a variable capacity compressor in a refrigeration system is controlled by regulating the flow of liquid refrigerant from the condenser to the evaporator in the system. A thermistor at the input of the compressor senses the quality or gas-liquid ratio of the suction gas and controls the position of a liquid refrigerant flow valve to control the flow rate of the liquid refrigerant, thereby controlling the quality of the suction gas at the input to the compressor. The position of the liquid refrigerant flow valve may also be controlled in accordance with the capacity setting of a variable capacity compressor.

Inventors

  • 👤 C Hamilton

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 19:46
CPC Classifications
F; F25; F25B; F25B41/00; F25B41/30; F25B41/31; F25B41/34; F25B41/35; F25B2600/00; F25B2600/21; F25B2700/00; F25B2700/21; F25B2700/2115; F25B2700/21151; Y; Y02; Y02B; Y02B30/00; Y02B30/70

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 236 words
In a refrigeration system including a compressor, a condenser and an evaporator connected in series in a closed loop wherein the compressor is a load controlled variable capacity compressor and the rate of flow of liquid refrigerant to the evaporator is controlled in accordance with the capacity of the compressor to maintain the liquid refrigeraant flow rate through the evaporator substantially equal to the mass flow rate through the compressor, the improvement comprising: a. valve means for controlling the rate of flow of liquid refrigerant into the evaporator; b. quality sensing means for producing a first control signal indicative of the quality of the refrigerant suction gas at the input of the compressor; c. circuit means responsive to said first control signal for controlling the position of said valve means to control said rate of flow of liquid refrigerant so that the quality of the suction gas is maintained at a desired optimum valve; d. compressor capacity sensing means for producing a second control signal indicative of the capacity of the compressor; and e. said circuit means being additionally responsive to said second control signal to control the position of said valve means in accordance with both said first and second control signals so that said rate of flow of liquid refrigerant is controlled by both the capacity of the compressor and also the quality of the refrigerant suction gas at the input of the compressor.
Claim 2
Dependent Claim 236 words
In a refrigeration system including a compressor, a condenser and an evaporator connected in series in a closed loop wherein the compressor is a load controlled variable capacity compressor and the rate of flow of liquid refrigerant to the evaporator is controlled in accordance with the capacity of the compressor to maintain the liquid refrigeraant flow rate through the evaporator substantially equal to the mass flow rate through the compressor, the improvement comprising: a. valve means for controlling the rate of flow of liquid refrigerant into the evaporator; b. quality sensing means for producing a first control signal indicative of the quality of the refrigerant suction gas at the input of the compressor; c. circuit means responsive to said first control signal for controlling the position of said valve means to control said rate of flow of liquid refrigerant so that the quality of the suction gas is maintained at a desired optimum valve; d. compressor capacity sensing means for producing a second control signal indicative of the capacity of the compressor; and e. said circuit means being additionally responsive to said second control signal to control the position of said valve means in accordance with both said first and second control signals so that said rate of flow of liquid refrigerant is controlled by both the capacity of the compressor and also the quality of the refrigerant suction gas at the input of the compressor.
Claim 3
Dependent Claim 177 words
A liquid refrigerant feed control as defined in claim 1 wherein said circuit means comprises: a. a normally balanced bridge circuit having first and second circuit paths normally carrying substantially equal currents; b. means connecting said quality sensing means in said first circuit path; c. means connecting said capacity sensing means in said second circuit path; d. first relay means connected in said first circuit path; e. second relay means connected in said second circuit path; and f. valve position control means connected to said valve means and selectively responsive to the operation of said first and second relay means for changing the position of said valve means, whereby changes in said first and second control signals unbalance said bridge circuit to cause unequal currents to flow in said first and second circuit Paths, thereby operating one of said relay means to operate said valve position control means which changes the position of said valve means so that said rate of flow of the liquid refrigerant is determined by both of said first and second control signals.

References Cited (Backward Citations)

US2534455A Cited
US2583178A Cited
US3397552A Cited
US3478534A Cited
US3408827A Cited
US3577743A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1976-05-28 1976-11-27 1977-05-29 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-05-28 1980-11-27 1981-05-29 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-05-28 1984-11-27 1985-05-29 $7700.00 Window Closed / Lapsed

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