PASTEURIZATION I57 



nected with metal strips which insures a more complete spread- 

 ing of the milk or cream.. 



3. Steam Boiler. — It is important that the boiler is of suffi- 

 cient size. The capacity of a boiler is rated by the amount of 

 water it is able to evaporate. A horse power is equivalent to the 

 evaporation of 34 1/2 pounds of water per hour at 212° F. If 

 milk is pasteurized to a temperature of 145° F. from initial 

 temperature of 60° F. then it will require approximately one 

 horse power for every 400 pounds of milk pasteurized per hour 

 or it wiU require approximately one horse power for 300 pounds 

 of milk per hour if it is heated to 180° or 185° F. It is advisable 

 to provide for surplus boiler capacity, as forcing the boiler 

 results in excessive fuel requirements. 



