In the cascade refrigerating system, two or more of refrigeration systems are connected as shown on Fig. 3-12. Cascade systems are often used in industrial processes where objects should be cooled to a temperature below 50CF (-46C).
Both systems operate simultaneously. System (right) has its evaporator (heat-absorbing part) organized for cooling the condenser to The evaporator system B. for the system In the supply of cooling the desired effect. Every system has a thermostatic expansion valve (TRV) to control the refrigerant. Low pressure fluid (dark blue) of the cooling system, high-pressure steam (red light) B. MCC One is used for both engines. This is due temperature sensing bulb on the evaporator b.
Engines used on the cascade system should be able to run under load. With the use of thermostatic valves, pressure balance on the outside of the cycle. Condenser-evaporator, as a rule, in shell-and-tube flooded evaporator type. Because these systems operate at very low temperatures, the refrigerant must be very dry.
Any moisture will condense on the needle seat TEV and stop the flow of refrigerant. System B should have a special refrigerant oil (wax-free, no moisture, and fluidity at low temperatures). Oil separators should be installed compressor condenser lines on both of these condensing units. This will help keep the oil in the compressor.
Compressors 