CATALOG OF THE MECHANICAL COLLECTIONS 185 



designed to hold the temperature of the brine at an approximately 

 even temperature. 



In operation a refrigerant gas, SO2, is compressed in the cylinder 

 of the compressor and delivered to the condenser, where it is cooled 

 to approximately the temperature of the air that is blown over the 

 condenser. The compressed and cooled SO2 then passes through a 

 reducing valve, which permits it to expand to a low pressure in the 

 cooling coils in the brine tank. As it is a physical property of a gas. 

 that in expanding it absorbs heat, the expanding SO2 takes heat 

 from the surrounding brine and thus lowers the temperature of the 

 chamber. The SO2 then returns to the compressor where it is again, 

 compressed and the process continues. When the brine is cold enough/ 

 the thermostat switch turns off the motor until the temperature rises 

 a few degrees when it starts the motor again. 



The unit is said to be the one that Edmund J. Copeland, then chief 

 engineer of the Kelvinator Corporation, believed to be the first one 

 of his designs to approach successful, automatic, dependable opera- 

 tion. It contains parts taken from earlier machines and now includes, 

 parts of later dates. 



49970—39 13 



