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PASTEURIZATION 



Regenerative Heaters and Coolers. Some of the heaters 

 and coolers are arranged on what is known as the regenerative 

 principle. The inflowing cold cream is heated by the hot cream 

 passing from the pasteurizer, and the outflowing hot cream is 

 cooled by the cold cream flowing to the pasteurizer. The hot 



and cold cream tend 

 to equalize their re- 

 spective temperatures 

 by passing in counter- 

 current directions, 

 M a n u f a c turers of 

 these coolers claim 

 that the regenerative 

 principle effects a sav- 

 ing of heat and cold 

 amounting to 25 to 35 

 per cent of the fuel 

 needed. 



Construction of 

 Flash Pasteurizers. 



Most of the contin- 

 uous pasteurizers are 

 constructed of copper 

 with heavily tinned 

 heating surface. Some of these pasteurizers are lined with Ger- 

 man silver. From the standpoint of heat conductivity there is 

 little choice between the two metals. Their efficiency is prac- 

 tically equally high. The German silver has the advantage of 

 preserving the brightness of its surface. In the copper-lined 

 machine the tin coating soon wears off. This, however, is no 

 serious objection as long as the copper surface is kept bright and 

 no verdigris is permitted to form. 



The details of construction and of power transmission vary 

 somewhat with the different types and makes of flash pasteur- 

 izers. Their descriptions are usually furnished by the respective 

 manufacturers of the machines. 



In the installation of flash pasteurizers the directions for 

 the same, which accompany the machines, should be carefully 



Tig. 24. Simplex regeneration pasteurizer 

 Courtesy D. H. Burrell & Co. 



