Advantages of Liquid Overfeed System

• Even Refrigerant distribution : The entire surface of the evaporator is wetted to give an even distribution of the refrigerant resulting in increased efficiency.
• Protection of Compressors : The Compressors are protected from liquid slugs resulting from fluctuating loads or malfunctioning controls.
• Hot gas Defrosting With simple controls, evaporators can be hot –gas defrosted with little disturbance to the system reducing wasted refrigeration.
• No effect of fluctuating ambient and condensing conditions : Refrigerant feed to evaporators are unaffected by fluctuating ambient and condensing conditions. The flow control regulators do not need to be adjusted after the initial setting, since the overfeed rates are not generally critical. Ideal for temperature accuracy.
• Minimum discharge temperature resulting minimum condenser fouling : Low-suction superheats are achieved where the suction lines between the low pressure receiver and the compressors are short. This condition causes a minimum discharge temperature, preventing lubrication breakdown and minimizing condenser fouling.
• Zero pressure Drops in the evaporators/Overfeed lines: Flash gas, resulting from refrigerant throttling losses, is removed at the low-pressure receiver before entering the evaporators. This gas is drown directly to the compressors and is eliminated as a factor in the system low side. It does not contribute to increase the pressure drops in the evaporators or overfeed lines. This results in low running time.
• Ease of Operation : Refrigerant level controls, level indicators, refrigerants pumps and oil drains are generally located in the equipment rooms, which are under operator surveillance. Allows all kind of operations to comfortably operate the system.
• Low maintenance : Because of ideal entering suction gas conditions, compressors last longer. There is less maintenance and fewer breakdowns. The oil circulation rate to the evaporators is reduced as a result of the low compressor discharge super heat.