Fig. 50. 



consists of a copper cylinder sur- 

 rounded by a water jacket, and 

 fitted with galvanized cast iron 

 heads; the upper head having a 

 removable cover, and the lower 

 head having a screw collar on the 

 inner side. Into the cylinder fits 

 the inner core, which is held in 

 place by being screwed on to the 

 collar in the bottom of the outer 

 cylinder. This screw joint be- 

 tween the outer and inner vessels 

 establishes a passage for the heat- 

 ing water, which, being run into 

 the filling funnel, fills both inner 

 and outer vessels to the level of 

 the overflow nipple. The steam 

 is fed into the inner core by a cen- 

 tral jet, and into the outer jacket 

 by a second jet. The milk is in- 

 produced at the bottom into the 

 thin space between the inner and 

 outer cylinders. As it flows up- 

 wardly to the milk outlet it passe s 

 between the two hot surfaces. 



TUBULAR HEATERS. 



In France, Mr. F. Fouche constructed what he calls a 

 multitubular pasteurizer. Fig. 51. 



The milk leaves the tank 

 M and enters the bottom 

 of the heater which is 

 heated by steam entering 

 at S. After passing 

 through a lot of straight 

 tubes the milk leaves the 

 heater and enters the cool- 

 er at the top. The tubes 

 in the cooler are cooled by 

 water from tank W. This 

 apparatus fills the bill as 

 Fi S . :,\. far as excluding the air 



