Continuous Process EVAPORATORS 175 
Construction—The Ruff Condensing Evaporator consists 
of the follow- 
ing three main 
parts: 
1, A vat or 
tank holding 
the milk to be 
condensed, and 
equipped with 
cover. The 
body of — this 
tank is of steel 
sheathing,  lin- 
ed on the inside 
with tinned 
copper. The 
cover or top is 
fitted with 
doors. 
55 _ 
4 One oF Fig. 76. The Buff condensing evaporator 
more steam- Courtesy of The Cream Production Co. 
heated hollow 
cylinders which revolve in the tank horizontally. These cylin- 
ders are constructed of special steel, highly polished. They are 
equipped with tinned bronze scrapers which remove the film of 
milk from the heating surface. The cylinders are fitted with 
a device for the automatic removal of the condensed steam, facil- 
itating the continuous heating with dry steam and therby in- 
hancing the rapidity of evaporation and augmenting the capacity 
of the machine. 
3. An arrangement for blowing atmospheric air into the 
lower part of the tank, causing it to rise up through the milk 
and to escape from the tank. 
4. Accessories.—The entire unit further comprises such 
accessories as a dial thermometer, high pressure blower with 
pipe connections from fan to evaporator and automatic return 
boiler feed pump, complete. 
Operation.—The milk is preheated to 145 degrees F. The 
hot milk runs into the tank by gravity, or is pumped in. In the 
