40 FRUIT-GKOWER, ST. JOSEPH, MO. 



desired temperatures in cold-storage rooms, and 

 these are known as the direct-expansion, the brine- 

 circulating, and the indirect or air-circulating sys- 

 tems. All three systems may be used in a cold-stor- 

 age plant, and in a given room or compartment the 

 air-circulating system is sometimes used in connec- 

 tion with the brine or the direct-expansion systems. 



In the direct-expansion system the liquefied gas 

 evaporates directly in the cooling refrigerator coils 

 or pipes which are placed in the refrigerator rooms. 

 The heat used in the evaporation of the gas is 

 absorbed from the room or from its contents, and the 

 temperature is thereby reduced. The gas then 

 returns to the compressor in the compression sys- 

 tem, or to the absorber in the absorption system, and 

 after being distilled in the latter case begins the 

 refrigerating cycle anew. 



In the brine-circulating system, the liquefied gas, 

 instead of evaporating directly in coils in the storage 

 room, evaporates in pipes surrounded by brine, or in 

 a brine cooler. The heat used in the evaporation of 

 the gas is absorbed from the brine rather than from 

 the room and its contents, as in the direct-expansion 

 system. The cold brine is then pumped to coils in 

 the storage room and the heat of the room and its 

 contents is absorbed by the cold brine. The warm 

 brine is then returned to the tank or cooler from 

 which it started and is recooled, while the gas 

 returns to the condenser or to the absorber to renew 

 the cycle of refrigeration. 



In the indirect or air-circulating system the air 

 in a well-insulated room, which is sometimes called 

 a coil room or a "bunker room," is first cooled, either 

 by the direct-expansion or by the brine-circulating 

 system. The cold air of the coil room is then forced 

 through ducts to the storage rooms. After passing 

 through the storage rooms it is returned by ducts to 



