DAIRY INSPECTION 185 
and close together. They are connected at either end 
so that fluid can flow from one tube into another. The 
cooling fluid enters the bottom pipe and flows upward 
through the various pipes, while the milk flows down- 
ward over the outer surface of the pipes from a reservoir 
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Fra. 20.—Tubular cooler, with continuous surface. 
at the top and is received in a collecting tank at the 
bottom. In some coolers of this type the pipes can be 
taken out to be cleaned and sterilized. Sometimes these 
coolers are arranged for ice water to run through the 
lower pipes and water through the upper pipes, the 
object being to save ice. The corrugated coolers have 
an ice-water section which can be attached to the bottom. 
