Condensed Milk and Milk Powder 



7i 



Samsung of Batch. — The samples can be drawn from the pan 

 by operating the two valves at the bottom. While the milk is con- 

 densing, the partial vacuum in the pan makes impossible the draw- 

 ing off of the sample by simply 

 opening the outlet. Instead of caus- 

 ing the milk to come out, air would 

 rush in with violent force and 

 would cause the milk in the pan to 

 be thrown over into the condenser, 

 besides dangerously jolting the ma- 

 chinery. For this reason, the outlet 

 is equipped with two valves, both 

 of which are closed during the con- 

 densing process. For taking sam- 

 ples, open the upper valve. This 

 Fig. 20. a con- allows the condensed milk to run 



venient device . , 



for sampling into the nipple between the two 



the condensed .. , T 



milk in the pan valves. JNow close the upper valve 

 Anhur te Hlr°rL and °P en the lower one. The milk 

 & Co - will run out freely. The first 



sample should be rejected, as it may contain water caught in the 

 nipple. For greater convenience, specially constructed sample 

 testers attached to the side of body of the pan may be used. 



Drawing off the Condensed Milk. — As soon as the evaporation 

 is completed, the steam is shut off from the jacket and coils, the 

 water 'valve is closed, the vacuum pump stopped and the vacuum 

 broken by opening the "blow-down" valve. The manhole cover is 

 then removed and the vacuum pump started again in order to re- 

 move the hot air over the milk. The milk is drawn into 40-quart 

 cans. The condensed milk should be drawn from the pan as rap- 

 idly as possible to prevent its superheating while in the pan. In 

 some factories a wire mesh or cloth strainer is attached to the out- 

 let of the- pan, so that the condensed milk is strained before it runs 

 into the cans. This practice is unnecessary and objectionable, as it 

 tends to retard the removal of the milk from the pan. 



Fig. 31. A convenient 



device for sampling 



condensed milk 



in the pan 



Courtesy of 

 Arthur Harris & Co. 



COOLING 



The condensed milk in the 40-quart cans has now a tempera- 

 ture of about 115 degrees F. to 130 degrees F. If it were allowed 



