Importance

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Abstract

A method for vaporizing the refrigerant trapped in the oil reservoir of a hermetic compressor. The refrigerant is vaporized by heat from a small pill shaped PTC heater (positive temperature coefficient heater) simply attached with adhesive tape in a shallow depression disposed near the bottom of the reservoir. The depression, formed on the compressor shell as a seamless indentation, extends into the reservoir and has a concave shape that conforms to the external surface of the heater. This provides a strong and hermetically sealed integral heater fixture having close fitting heat conductive contact with its associated heater element. The heater, being disposed in the shallow indentation, is placed in more direct contact with the liquid refrigerant, which tends to settle at the bottom of the reservoir due to its density being greater than that of the oil. In addition, because the PTC heater has a positive temperature coefficient, higher temperature levels are obtained when the heater is mounted in a shallow indentation versus a deep well. A shallow indentation exposes a portion of the PTC heater to ambient air which is less heat conductive than liquid refrigerant or oil. With less heat conducted from the heater, its temperature rises which provides a higher concentration of heat at the bottom of the shell. Moreover, the higher temperature increases the resistance of the PTC heater and thus reduces its power consumption.

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First Claim