Several disadvantages are that Steam Jet, units can be used for refrigerating temperatures no Lower then 32°F. About twice as much heat must be removed from the condenser of the Steam-Jet unit per Ton of’ refrigeration as much it removed in the vapor compression system.
Steam Jet unit find there greatest popularity in Industrial Plants where Steam is available and cheap and where cooling tower capacity to handle the large quantities of condenser cooling’ water is relatively inexpensive. Process Industries, such as Chemical Plants, often need refrigeration of moderate temperatures and frequently use Steam Jets for the purpose. In sizes above about 75-Tons, the initial cost of Steam Jet units is competitive with vapor compression machines.
Some unique applications of Steam Jets are Fruit Juice concentration and vacuum pre-cooling of vegetable. In Juice Concentration, Steam Jets evaporate water vapor at low pressure concentration therefore occurs at that low temperature, which is necessary to preserve the flavor of the juices many waste coast lettuce growers who formerly iced there product before loading it into refrigerated railway cars now save handling costs by putting cartons of lettuce into large chambers, then pulling a vacuum in the chamber with Steam Jets. The evaporation of’ the small amount of surface moisture drops the temperature of the lettuce to 34°F in about 15 or 20 minutes.
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