. Railway mechanical engineer . en in continuous service for fouryears in the stockyards district of Chicago, handling trafficin a radius of 24 miles. Fig. 1 shows diagrammatically the process as used on twoof these trucks. The plant has a refrigerating capacity of1000 lb. Its source of energ) is a gasoline engine and therefriegerating mediiun is the air. \Vith this combination theonly operating supplies necessary are gasoline and oil. Therefrigerating mechanism is located in a space occup)ing 2 the length of the body on the front end, leaving a receiv-ing chamber for perishable goods 23
. Railway mechanical engineer . en in continuous service for fouryears in the stockyards district of Chicago, handling trafficin a radius of 24 miles. Fig. 1 shows diagrammatically the process as used on twoof these trucks. The plant has a refrigerating capacity of1000 lb. Its source of energ) is a gasoline engine and therefriegerating mediiun is the air. \Vith this combination theonly operating supplies necessary are gasoline and oil. Therefrigerating mechanism is located in a space occup)ing 2 the length of the body on the front end, leaving a receiv-ing chamber for perishable goods 23 ft. 6 in. long, 7 ft. 4 , and 6 ft. 2 in. high. The refrigerating coils are lo-cated in the roof of the car and are fastened to thesteel-plate and angle-iron carlines, which makes it possibleto swing carcasses from the coils by meat hooks. The re-frigerating machine is adjusted thermostatically to maintainthe temperature of 36 deg. F. It can also be adjusted toreasonably lower room temperatures if desired, it being pos-. Fig. 1 — Diagram of Dense Ai ocess of Refrigeration sible to the expanded air temperature of the refriger-ating medium to 30 deg. below zero. Th^ Refrigerating Machine. The dense-air process isbased upon the fact that a perfect gas under pressure, ex-panding adiabatically and performing external work willsuffer a drop in temperature projwrtional to the mechanicalenergy produced. Its fundamental advantages lie in thesecharacteristics: There is an unlimited supply of the agentevfrywhere, as air is the medium; it is readily dried by theuse of deliquescent salts, it is innoxious, non-poisonous, andits explosive force lies only in its expansibility under pressure;a leak may \>e readily sealed and the air, once dried, becomesa [K-rfect medium of refrigeration at temperatures much lowerthan is possible with any agent except COj. The refrigerating unit consists of a employingtwo cylinders (5 in. Ixjre by 5 in. stroke), and an integralexp
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectrailroadengineering
