106 MODERN FRUIT MARKETING 



The Condenser. "The condenser is a series of pipes 

 through which the ammonia gas is forced by the com- 

 pressor, and cooled by a constant supply of cold water. 

 The heat acquired during both the expansion and com- 

 pression of the ammonia gas is absorbed by the cold water 

 surrounding the pipes, and by the combined effect of the 

 cooling water and pressure exerted by the compressor, 

 the gas becomes liquified, and is then in proper condi- 

 tion to do the actual work of refrigeration. 



The Expansion Coils. ''The expansion coils are 

 placed either in a brine bath or directly in the room 

 to be cooled, and the liquified ammonia gas from the con- 

 denser is fed into these coils by a sensitive valve reduc- 

 ing the pressure to 5 to 25 pounds per square inch, where 

 it rapidly re-expands into a gaseous state, and by so 

 doing, absorbs the heat from the surrounding brine or 

 air, producing an intense cold. 



"The expansion coils are connected with the suction 

 pipes of the compressor, and after the gas has per- 

 formed its refrigerating work, it is drawn into the 

 cylinder of the compressor and is again driven on its 

 round of operation, the same gas being used continu- 

 ously. 



Utilizing the Cold. "The methods in practice for 

 utilizing the cold produced in this way are the brine 

 system, and the direct expansion system. 



The Brine System. "In the brine system a tank is 

 used containing a strong solution of brine, which is 

 cooled to a low temperature by submerging the ammonia 

 expansion coils in the brine or by means of a double 

 pipe brine cooler, the chilled brine being circulated 

 through a series of pipes placed in the rooms to be cooled 



