APPLICATION OF REFRIGEEATION TO HANDLING OF MILK. 21 



mon salt. The solution should not be stronger than the temperature 

 to be maintained requires, as the specific heat. of brine decreases as 

 the strength of the solution increases. A part of the pipe coils are 

 placed in the tank containing the mixture of salt and ice, and a 

 part are led down into the cooling room below. The coils of pipe 

 that are in the cooling room absorb heat from the stored goods 



Fig. 8. — Gravity brine system. v 



and those in the tank give up heat to the freezing mixture of salt 

 and ice. 



The operation of this system is as follows: The brine in that part 

 of the pipe circuit in the tank becomes heavier as it is cooled and 

 flows down into the storage room, forcing the warmer and there- 

 fore lighter brine up into the coils in the tank. The heat ab- 

 sorbed in the storage room is transferred to the mixture in the 

 tank by the natural circulation of the medium. This system is to a 

 certain extent automatic in its operation, as an abnormal rise in 

 temperature of the storage compartment from any cause increases 

 the velocity of the brine circulation and therefore increases the re- 



