78 SWEETENED CONDENSED Mi1L,.K—CONDENSING 
feet above the water level of the cistern in which the discharge 
pipe from the condenser terminates. “The height of the condenser 
depends on the barometric pressure of the location where it is 
installed. The lower the altitude and, therefore, the higher the 
atmospheric pressure, the higher must the condenser be above 
the cistern. At the sea level, the atmospheric pressure sustains 
a water column about thirty-four feet high. This water column 
in the discharge pipe seals the vacuum and at the same time 
permits the water from the spray and the condensation water 
to escape automatically. ‘The cistern in which the water column 
terminates should be of sufficient size to hold about one-third 
more water than the capacity of the entire length of the discharge 
pipe calls for and should have a large overflow into the sewer. 
\When the pan is in operation and a uniform vacuum is main- 
tained, the level of the water column remains constant and the 
excess water from the condenser overflows from the cistern into 
the sewer. 
The Wet-Vacuum Spray 
Condenser consists of a huge 
hollow cylinder of brass or iron, 
ARTHUR HARRIS & CO. 
2 CHICAGO, 
usually, but not necessarily, 
horizontal. 
The horizontal spray con- 
Fig. 26. Wet-Vacuum horizontal 
densers are usually equipped 
F spray condenser 
with a perforated spray pipe, Gourtésy of Arthur Harris’@ Co: 
placed lengthwise in the cyl- 
inder. This spray pipe should run close to the top side of the 
cylinder, so as to give the spray that escapes from the holes on 
the upper side of the spray pipe a chance to strike the top of the 
horizontal cylinder with foree and to become atomized. ‘The 
spray pipe connects at the end nearest the pan with the pipe 
supplying the cooling water. \When the pan ts in operation, 
a shower of cold water issues forth from the perforations of the 
spray pipe as the result of the reduced pressure in pan and con- 
denser. The foree with which the water escapes these perfora- 
tions is further augmented by the fact that in most cases the 
water supply tank is located higher than the condenser. The 
hot vapors arising from the boiling milk in the pan are drawn 
over into the condenser, where they come in contact with the 
