26 



Ibs. of milk per hour from 54 to 155 Fah., with a circulation of 

 water at 180. Used as a cooler, it cooled only 1,000 Ibs. per hour 

 from 155 to 60 with water pumped over and over through a tank 

 with ice. 



In Sweden DE LAVAL solved the protection problem as shown 

 in Fig. 5, which takes the place of the heater in his combined heater 

 and cooler (Fig. 14). 



This apparatus consists of two closed double vessels fitting one 

 into the other in such a way as to form concentric narrow apertures 

 of large surface, through which the milk is forced. The aperture is 

 only about -J of an inch and the milk, which is kept in constant 

 motion, is rapidly and evenly heated, without allowing any albumen 

 to coagulate. 



Each vessel has a pipe (a) which passes down close to the bot- 

 tom ; these two pipes are at the upper end joined at b where the steam 

 enters. 



Both vessels are also connected by a pipe (c) by which the con- 

 densed steam escapes from the inner vessel into the outer, from 

 which it again flows through the pipe (d). The inlet of the milk is 

 regulated by an ordinary regulator cup (e) with float, same as used 

 on the separators. After the milk has passed down through the inner 

 conical aperture, it rises through the outer one and flows over the rim 

 of the annular receiver placed round the above named regulator cup, 

 and flows off through the pipe (g). At the base of the outer vessel 

 are fitted a faucet ( h ) ( for drawing off the milk remaining in the ap- 

 H paratus after the work is finished) and a 



. screw-plug (1) for emptying out the heating 

 water from the outer vessel. The inner ves- 

 sel is emptied of its water through the open- 

 ing n, by means of a syphon. 



The apparatus is made in three sizes: 

 No. 3 heats 650 liters ( = 150 gallons ) per hour 

 No. 4 heats 1,200 liters (=265 gallons) per hour 

 No. 5 heats 1,800 liters ( =400 gallons) per hour 

 Similar heaters have been used by Mr. 

 Bentley who uses two or more sets consisting 

 of two cans (Fig. 22), an outer one B B B B, 

 B aiid an inner one A A A A. The inner one has 

 a tube H through which the milk flows under 



m 



A 

 Fig. 22. 



