EVAI'UKATKU M IL,K wSllAKJNC, 



127 



lactic acid, a concenlration of two and one-fourth parts of fresh 

 milk to one part of evaporated milk causes the evap(jrated milk 

 to contain .17 X 2J5 = .38 per cent lactic acid. With this amount 

 of acid acting- on the casein, it is not difficult to understand why 



a coagulum is often formed in 

 the sterilizer. AMiilc the forma- 

 tion of this coag"u!um may he 

 partly a\oided, under certain 

 conditions it appears in evevy 

 factory and there are more 

 hatches, especially in summer, 

 that come from the sterilizer 

 coagulated than otherwise, 

 f n this condition the product is not marketable. Sr.me means 

 must be provided, therefore, to break up this curd and reduce 

 the contents of the cans to a smooth, homogeneous and creamy 

 body. For this purpose a mechanical shaker is used. 



Fig. 48. Shaker 



Courtesy of Arthur Harris & Co. 



Fig. 49. Siiaker 

 Courtesy of The Engineering Company 



Method of Shaking. — The shaker consists of one or more 

 heavy iron boxes or boxes made of black iron pipes. These 

 boxes are attached to an eccentric. The trays filled with evapo- 

 rated milk cans are firmly wedged into these boxres. When the 

 shaker is in operation, the cans are shaken back and forth violent- 

 ly, causing the ctird in the cans to be broken up. 



Speed of the Shaker. — If the shaker is to perform its work 

 properly, it must have long enough a stroke and run fast enough 

 to cause most vigorous agitation. The stroke should be not less 

 than about two and one-half inches and the eccentric should re- 



