EVAPORATED MILK COOLING 



115 



homogenized it should be cooled as soon as it leaves the vacuum 

 pan. 



Holding in tanks. The establishment and enforcement of 

 a Government standard of composition and the tendency of the 

 manufacturer, in the face of increasingly keen competition which 

 narrows down the margin of profit and demands more exacting 

 attention to the cost of manufacture, to reduce his output to 

 a uniform composition that complies with the Government 

 standard but does not exceed it, have resulted in the adoption, 

 especially among the larger condenseries of the practice of 

 standardizing or unifying each day's output by mixing together 

 all the batches of evaporated milk of one and the same day's 

 make. 



This practice necessitates the use 

 of one or more large tanks with 

 facilities for refrigeration of their 

 contents. This need has been and is 

 being admirably met by the installa- 

 tion of jacketed glass enameled cir- 

 cular tanks, ranging in capacity from 

 about 15,000 to 60,000 pounds. 

 These tanks are equipped with 

 one or more propellers which serve 

 to agitate the evaporated milk, mix- 

 ing it and hastening the cooling. 

 The propellers in the latest im- 

 proved holding and cooling tanks 

 are located near the side or periphery 

 of the tank and are driven by in- 

 dependent motor, or by belt power. 

 It has been found that the thus ex- 

 centrically placed propeller, when set at the proper angle, is 

 more efficient in its agitation and in bringing all portions of the 

 evaporated milk in direct contact with the cooling jacket than 

 is the case with the centrally located vertical agitator, which 

 merely gives the contents of the tank a circular motion. 



In factories where these large glass tanks are installed, each 

 successive batch of evaporated milk is transferred, at the con- 

 clusion of the process of evaporation and homogenization, to 



Fig. 42. Holding tank for 



evaporated milk 

 Courtesy of The Pfaudler Co. 



