SWEETENED CONDENSED Mi1.K—CONDENSING 81 
In another type of vertical spray condenser the insulated 
vapor tube in the center is surrounded by a spray chamber of 
much greater width, and the water spray starts near the bottom 
of the chamber from perforations in a circular coil. The per- 
forations are so located that the spray slants upward and out- 
ward. As it strikes the periphery of the condenser, it is deflected 
downward and toward the center. It is claimed that in this 
case two sheets of spray are formed, through which the vapors 
must pass. Baffle plates extend downward and outward from the 
top of the vapor tube preventing any of the spray from entering 
the vapor tube. Manholes with covers are provided at the sides 
to make possible easy cleaning of the condenser, 
Instead of the condenser being attached direct to the dome 
of the vacuum pan, the condenser may form a part of the vacuum 
pump. This arrangement is feasible both in the case of the wet- 
vacuum spray condenser and in the case of the surface condenser. 
The chief difference between the wet-vacuum condenser and 
the barometric condenser is that in the wet-vacuum condenser 
the water from the condenser passes through the vacuum pump, 
while in the barometric condenser the water does not pass 
through the vacuum pump, but goes dircet into the sewer and the 
vacuum is scaled by the barometric water column. So far as 
practical experience has shown, there is no material difference 
in the efficiency between these two types of condensers. The 
water column of the barometric condenser helps somewhat to 
maintain a uniform vacuum. It necessitates, however, the in- 
stallation of the pan inconyeniently high and requires somewhat 
more expensive machinery than is the case with the wet-vacuum 
condenser. The chief difference between both of these systems 
and the surface condenser is that, in the wet-vacuum and baro- 
metric condensers the condensed vapors mix with the cooling 
water, while in the surface condenser the condensed vapors are 
collected and carried off separately and without mixing with 
the cooling water. In the case of condensing liquids, the vapors 
of which are of commercial value, the surface condenser must be 
used. The surface condenser, however, is of relatively small 
capacity and the cooling water cannot be utilized as economically 
as in the case of the other systems. Where large quantities of 
vapors are to be handled and the vapors have no commercial 
