140 MANAGEMENT OF DAIRY PLANTS 



or the interior of the boiler with scale. The exterior of the tubes 

 is readily cleaned and should be done daily. The formation of 

 scale on the inside of the boiler is more difficult to prevent. The 

 most common impurities in water causing formation of scales 

 are sulphates and chlorides of lime and magnesia and bicarbon- 

 ate of magnesia and lime; also iron silica and other ingredients 

 are found. It is recommended to use caustic soda in the propor- 

 tion of one fourth pound per horse power; the boiler is then 

 steamed for a day before cleaning. The scales become soft 

 and are readily removed. Soda ash or carbonate of soda will 

 decompose sulphates and chlorides of lime and magnesia. 



4. Insulation of Boiler and Steam Pipes. — Losses of steam 

 from boiler, pipes, and engine due to radiation and leakage are 

 estimated variously by writers. Such losses may be estimated 

 for the average creamery at 10 per cent of the steam produced. 

 This loss may be reduced by having boiler and steam pipes 

 properly insulated and by preventing leakage from pipes and 

 valves. 



Cost of Power When Operating a Steam Engine. — Con- 

 sider that I pound of coal produces 5.5 pounds of steam and 

 that the cost of such coal is $5.50 per ton of 2,000 pounds. If 40 

 pounds of steam are used for a horse power per hour then the 



amount of coal required is — or 7.27 pounds. The cost of a 

 horse power per hour is equivalent to. 



7.27 X i?!;© 



' ' ^ ^^ . or 2 cents 



GASOLINE FOR POWER 



The gasoline engines have during recent years been installed 

 in several creameries. The principaL advantages claimed for 

 them are: 



1. Economical in cost of fuel and attendance. 



2. Automatic in operation. 



