HEAT TREAT HOT GAS SYSTEM

摘要

A hot gas heat treat system is employed to cool mix in a hopper and a freezing cylinder and to heat the mix for pasteurization. A hopper liquid line solenoid valve at the inlet of the hopper and a cylinder liquid line solenoid valve at the inlet of the freezing cylinder each control the flow of refrigerant to the expansion valves which further control the flow of refrigerant that flows around the hopper and the freezing cylinder, respectively. A hopper hot gas solenoid valve at the inlet of the hopper and a cylinder hot gas solenoid valve at the inlet of the freezing cylinder control the flow of refrigerant from the compressor that flows around the hopper and the freezing cylinder. The system further includes a hot gas bypass valve that is opened when only the hopper is being cooled to provide additional load to the compressor. An EPR valve is positioned proximate to the hopper discharge to vary the temperature of the refrigerant exchanging heat with the hopper. A CPR valve is employed to control the inlet pressure of the compressor by reducing the amount of hot refrigerant flowing into the compressor suction. The system further includes a TREV valve to allow for liquid refrigerant injection to the compressor suction to control excessive compressor discharge during the cool cycle.