72 SWEETENED CONDENSED MILK CONDENSING 



of the vacuum pump through which the water and the condensed 

 vapors in the condenser escape. 



In the vertical spray condenser the condenser cylinder is up- 

 right, located either on top of the pan or at some distance, as is the 

 case, for instance, where a catch-all is installed between pan and 

 condenser. The interior arrangement of the vertical condenser 

 varies somewhat with the different makes. The vertical condenser 

 most widely used in American condenseries consists of a double 

 insulated vapor tube setting on top of the pan. This insulated tube 

 is surrounded by and connects with a spray chamber, which termi- 

 nates at its top in a perforated metal plate and which has an open- 

 ing in the side near the bottom that connects with the vacuum pump 

 supplying the suction and that permits the escape of the condensed 

 vapors and cooling water. The cooling water enters at the top of 

 the condenser. Immediately underneath the water inlet it strikes 

 a metal cone or disc which prevents the water from running into 

 the vapor tube, and distributes it evenly over the perforated spray 

 plate. The vapor rises into the vapor tube of the condenser and is 

 drawn over into the spray chamber surrounding it, where the 

 vapor is condensed by the spray of water issuing from the per- 

 forated spray plate which tops the spray chamber and which con- 

 tains a large number of very small holes. As the water falls 

 through these openings by gravity, the spray is uniform and con- 

 stant and does not depend on the amount of water used, nor does 

 it require water pressure on the 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 direct into the sewer and the vacuum is 

 sealed by the barometric water column. So far as practical experi- 

 ence has shown, there is no material difference in the efficiency be- 

 tween these two types of condensers. The water column of the 

 barometric condenser helps somewhat to maintain a uniform vacuum. 

 It necessitates, however, the installation of the pan inconveniently 

 high and requires somewhat more expensive machinery than is the 

 case with the wet-vacuum condenser. The chief difference between 



