236 CREAMURY BUTTER MAKING 



melting into water at the same temperature. Its actual 

 ice making capacity is usually about 50% less. 



Size of Compressor. In a moderately well insulated 

 creamery handling from twenty to twenty-five thousand 

 pounds of milk daily, a four-ton compressor will be large 

 enotigh. With a compressor of this size the machinery 

 will not have to be run more than five or six hours a day. 

 If the machinery is run longer than this a smaller com- 

 pressor will do the work. 



Power Required to Operate. The power required per 

 ton of refrigeration is less the larger the machine. With 

 a four-ton compressor the power required is from two to 

 two and one-half horse power per ton of refrigerating 

 capacity in twenty-four hours. 



Refrigerating Pipes. The refrigerating pipes vary 

 from one to two inches in diameter. With moderatelv 

 good insulation it is estimated that by the direct expansion 

 system one running foot of two-inch piping will keep a 

 room of forty cubic feet content at a temperature of ;j,2'" 

 F. With brine nearly twice this amount of piping would 

 be necessary. 



For cooling the brine in the brine tank, about 140 feet 

 of ij4"inch pipes are required per ton of refrigerating 

 capacity. 



Expense of Operating. \\'hen a refrigerating plant 

 has once been installed and charged with the necessarv 

 ammonia, the principal expense connected with it will be 

 the power re(|uired to operate the compressor. This 

 power in a creamery is supplied by the creamerv engine. 

 The ammonia, being used o\er and over again, will add 

 but a trifle to the running expenses. Nor can the water 

 used for cooling the ammonia vapors add much to the 

 cost of operating. It is true, however, that the rcfrigera- 



