ON 
SWEETENED CONDENSED MILK—CONDENSING 8 
temperature of the condenser discharge should be about 110 de- 
grees F. A Jower temperature would cause excessive and un- 
economic use of water unless the available water has a temper- 
ature lower than is the case in the average .\merican condensery 
(30 to 60° F.). The basin on the vacuum eylinder should be 
kept filled with water te prevent admission of air to the cylinder 
through the stuffing box, and the spray pipe. jet, or spray plate in 
the condenser should be inspected often to make sure that the 
perforations are net clogged. ‘The stuffing box of the evlinder 
should be well packed with a good quality of packing and the 
steam cylinder well oiled. Start the pump slowly. Belt-driven 
Fig. 31. Wet-vacuum pump 
Courtesy of Union Steam Pump Co 
pumps, especially those equipped with a fly-wheel, insure greater 
uniformity of speed than direct-acting, 
i 
Steam-driven pumps should be furmshed with a high gerade gov- 
steam-driven pumps. 
ernor. The vacuum pump should have a capacity proportionate 
to the size of the vacuum pan, amount of heating surface, steam 
pressure and temperature of condensing water. 
Science and Practice of Evaporating in Vacuo. 
Purpose of Condensing in Vacuo.—The important adyan- 
tages gained by evaporating milk under reduced pressure, or in 
vacuo, are: economy of evaporation, rapidity of evaporation, low 
temperature and large capacity of apparatus. All of these features 
are essential in the successful condensing of milk. 
