Hermetic compressor discharge line thermal block

Abstract

A hermetic compressor discharge line thermal block is hermetically coupled in the discharge line between a condenser and compressor adjacent to the discharge outlet of the compressor. The device is formed to define a well for removably receiving a heating element, and has a hermetically sealed chamber substantially surrounding the heater well and electric heating element. Upon compressor shutdown, liquid refrigerant migrating from the condenser partially fills the chamber, thereby decreasing the temperature of the heating element below a predetermined temperature, thereby causing the heating element to become electrically conductive to supply heat to the chamber to evaporate the liquid refrigerant therein and to prevent further accumulation of liquid. If a positive temperature coefficient heater is used, after thermal stabilization and during compressor operation, the heat generated either by the compressor or by the heating element itself raises the temperature of the element, thereby causing the heating element to become substantially less electrically conductive to reduce the supply of heat to the chamber. The discharge line thermal block device prevents the migration of liquid refrigerant from the condenser to the compressor to thereby prevent slugging during compressor start-up.