US3638446A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low ambient control of subcooling control valve
Assignee: Individual
•
Filing: 1969-06-27
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Granted: 1972-02-01
•
Expires: 1989-06-27
Abstract
Abstract A refrigeration system has a condenser coil cooled by outdoor air, and has a subcooling control valve with its thermal bulb in heat exchange contact with the liquid line from the condenser coil. The bulb is normally heated by an electric heater, and the valve is adjusted to provide a desired amount of subcooling of the liquid when the heat applied to the bulb by the electric heater is maximum. At low outdoor temperatures when the condenser pressure decreases so that a conventional subcooling control valve would not open sufficiently, the electric heat is automatically reduced so that the valve opens wider.
Inventors
- 👤 Robert T Palmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:39
CPC Classifications
F; F25; F25B; F25B41/00; F25B41/30; F25B41/31; F25B41/34; F25B2341/00; F25B2341/06; F25B2341/063; F25B2341/068; F25B2341/0681; Y; Y02; Y02B; Y02B30/00; Y02B30/70
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
118 words
In a refrigeration system having a refrigerant compressor, a condenser coil cooled by outdoor air, a liquid tube, a subcooling control valve, an evaporator coil, and a suction gas tube connected in series in the order named, said valve having a thermal bulb in heat exchange contact with said liquid tube, the improvement comprising an electric heater for said bulb, and means for energizing said heater to apply maximum electric heat to said bulb during normal operation of, with normal pressure and temperature within, said system, and for reducing the electric heat applied to said bulb during operation of said system when a low outdoor temperature causes the pressure and temperature within the system to decrease below normal.
Claim 2
Dependent Claim
118 words
In a refrigeration system having a refrigerant compressor, a condenser coil cooled by outdoor air, a liquid tube, a subcooling control valve, an evaporator coil, and a suction gas tube connected in series in the order named, said valve having a thermal bulb in heat exchange contact with said liquid tube, the improvement comprising an electric heater for said bulb, and means for energizing said heater to apply maximum electric heat to said bulb during normal operation of, with normal pressure and temperature within, said system, and for reducing the electric heat applied to said bulb during operation of said system when a low outdoor temperature causes the pressure and temperature within the system to decrease below normal.
Claim 3
Dependent Claim
13 words
The improvement claimed in claim 1 in which said means includes temperature-responsive means.
Claim 4
Dependent Claim
31 words
The improvement claimed in claim 1 in which said means includes means responsive to the temperature and quantity of refrigerant liquid flowing from said evaporator coil into said suction gas tube.
Claim 5
Dependent Claim
23 words
The improvement claimed in claim 3 in which said means responsive to temperature and quantity comprises a thermistor within said suction gas tube.
Claim 6
Dependent Claim
34 words
The improvement claimed in claim 1 in which said means includes means responsive to the temperature of the refrigerant liquid within said system, upstream with respect to refrigerant flow, of said suction gas tube.
Claim 7
Dependent Claim
14 words
The improvement claimed in claim 5 in which said temperature-responsive means comprises a thermistor.
Claim 8
Dependent Claim
26 words
The improvement claimed in claim 1 in which said means includes means responsive to the temperature of the refrigerant between said evaporator coil and said compressor.
Claim 9
Dependent Claim
16 words
The improvement claimed in claim 7 in which said means responsive to temperature comprises a thermistor.
Claim 10
Dependent Claim
27 words
The improvement claimed in claim 1 in which said means comprises electric supply connections, and variable resistor means connected in series with said heater to said connections.
Claim 11
Dependent Claim
19 words
The improvement claimed in claim 9 in which said resistor means comprises a thermistor within said suction gas tube.
Claim 12
Dependent Claim
28 words
The improvement claimed in claim 9 in which said resistor means comprises a thermistor responsive to the temperature of the refrigerant between said evaporator coil and said compressor.
Claim 13
Dependent Claim
36 words
The improvement claimed in claim 9 in which said resistor means comprises a thermistor responsive to the temperature of the refrigerant liquid within said system, upstream with respect to refrigerant flow, of said suction gas tube.
Claim 14
Dependent Claim
42 words
The improvement claimed in claim 9 in which said resistor means comprises a thermistor within said suction gas tube, and in which said suction gas tube is in heat exchange contact with said liquid tube between said thermistor and said evaporator coil.
Claim 15
Dependent Claim
27 words
The improvement claimed in claim 13 in which said suction gas tube is in heat exchange contact with said liquid tube between said thermistor and said compressor.
Claim 16
Dependent Claim
33 words
The improvement claimed in claim 9 in which said resistor means comprises a thermistor responsive to the temperature and quantity of refrigerant liquid flowing from said evaporator coil into said suction gas tube.
Claim 17
Dependent Claim
36 words
The improvement claimed in claim 9 in which means responsive to pressure within said system is provided, and which has means for varying the resistance of said resistor means in accordance with changes in said pressure.
Claim 18
Dependent Claim
26 words
The improvement claimed in claim 16 in which said pressure-responsive means responds to pressure within said system between said suction gas tube and said condenser coil.
Claim 19
Dependent Claim
24 words
The improvement claimed in claim 16 in which said pressure-responsive means responds to pressure within said system between said evaporator coil and said compressor.
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) | 1975-01-31 | 1975-08-02 | 1976-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-31 | 1979-08-02 | 1980-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-31 | 1983-08-02 | 1984-02-01 | $7700.00 | Window Closed / Lapsed |