2 
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 
