APPLICATION OF REFRIGERATION" TO HANDLING OF MILK. 45 
in the piping will be 1 .5 X 52 X 1 6 = 1 ,248 B. T. U. Consequently the 
hold-over period due to the brine in the piping is ' , nn =0.58 
hour. If there are 2,000 pounds of butter stored in the room, it will 
also assist in increasing the time of shut down for a 3-degree rise in 
room and contents. The rise in temperature of the butter for a 
34 400 
16-hour shut down will be nno ' ft , . , = 31 .3 degrees, or 3 
degrees in 1.53 hours. Therefore, the total time the plant can be 
shut down for a 3-degree rise in temperature of room and contents 
is 0.58 + 1.53=2.1 hours. Consequently it becomes necessary with 
this system to circulate the brine continuously. If, however, a 
sufficient volume of low-temperature brine is available for circulating 
through the coils, the refrigerating machine may be shut down for 
mmmmz&mmm. 
Fig. 21. — Elementary diagram, of brine storage system. 
a time, depending on the volume and temperature of the brine, by 
continuing the action of the pump. 
BRINE-STORAGE SYSTEM. 
In place of the continuous brine coils employed in the brine-circu- 
lating system there is a modified "brine system designed to give 
practically the same results (fig. 21). This is known as the brine- 
storage system and consists in replacing the main tank by several 
smaller ones located in the various compartments of the cold-storage 
plant. With an equipment of this kind the initial cost of the brine 
pump, the main brine tank, the necessary piping for brine circulation, 
and the brine-tank insulation are eliminated, as well as the power 
to operate the brine pump and the radiation losses through the 
brine tank and pipe insulation. 
The heat-absorbing surfaces of the various small tanks entirely 
replace those of the brine coils. In practice, however, from one third 
to two-thirds of the direct expansion coils are placed outside of the 
brine, in direct contact with the air in the cold-storage room, in 
