SWEETENED CONDENSED MILK CONDENSING 



73 



Fig. 19. Steam coils in Harris pan 



Courtesy of Arthur Harris & Co. 



face in different makes of pans, ranging from about 120 to 205 

 square feet, in the case of six foot pans. 



In the latest improvement 

 in coils each independent coil 

 makes only one turn in the pan 

 and the inner and outer coils 

 have the same inlet and dis- 

 charge and are placed on the 

 same level. This permits of 

 the installation of a larger 

 number of independent coils, 

 each placed at a different level. 

 Tn this manner the coils can be 

 utilized to better advantage. 

 This is especially significant 

 when the volume of milk in the 

 pan is very small, making pos- 

 sible 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 sub- 

 merged. This arrangement increases the heating efficiency 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 



