Sweetened Condensed Milk — Condensing 67 



in the pan is very small, making possible the operation- of the lower 

 coils independent of the upper coils and thereby avoiding the danger 

 of burning the milk, which inevitably occurs when the heated coils 

 are not completely submerged. This arrangement increases the 

 heating efificiency of the pan, heat can be turned on the lowest coil 

 almost immediately after starting operation, and toward the end 

 of the batch, when the milk again boils low, some of the coils are 

 still covered and can be used. The shorter length of these coils 

 from inlet to exhaust also makes possible the simultaneous utilization 

 of a greater volume of steam. These combined features materially 

 increase the rapidity of evaporation and augment the capacity of the 

 pan. These improved coils have the further advantage that their 

 exhausts do not have to be carried through the jacket, but pass 

 through the body of the pan. 



Jacket and coils are connected independently with the direct 

 steam main from the boiler. Each connection at the pan should 

 carry a valve and a steam gauge on the pan-side of the valve. The 

 main steam line and connections leading to pan should be properly 

 insulated by proper pipe coverings, in order to supply the pan with 

 as dry steam as possible. 



The drips or discharge ends of the jacket and coils are con- 

 nected with the boiler feed water tank. If the pan has sufficient 

 heating surface and is operated properly, the drip ends of the jacket 

 and coils should discharge warm water only, and not free steam. 

 The jacket and coils should be free at the drip or discharge ends 

 so that all condensation water may be quickly and continuously 

 removed. This is necessary in order to make the most economical 

 use of the steam and to secure high efificiency of evaporation. In 

 order to guard against back pressure the drips may be equipped 

 with suitable check valves. 



Through the walls of the body of the pan also enters the milk 

 draw pipe. This pipe connects with the hot well and through it the 

 milk rushes into the pan. Immediately outside of the pan the milk 

 pipe should be equipped with a valve to regulate the inflow. The 

 size of the milk draw pipe and valve is governed by the capacity of 

 the pan ; usually two to three inches in diameter. Inside of the pan 

 the milk pipe should be turned down. If this provision is not made, 

 the milk shoots straight across the pan atomizing into a dense spray, 

 which is partly drawn over into the condenser, causing loss of milk. 



