384 ECONOMIC OPERATION OF CREAMERY 



there are no additional expenses and very little extra labor 

 required. 



Cleaning the Boiler. The amount of coal used will vary with 

 several factors, viz., cleanliness of flues, sediment in the boiler, 

 condition of fire, kind of boiler, steam leaks, pipe insulation, etc. 

 The two first factors are frequently neglected. The flues should 

 be cleaned every morning before the day's run. The inside of 

 the boiler should be kept clean. Heavy scale on the inside of the 

 boiler and flues, and heavy sediments on the bottom of the boiler, 

 should never be allowed to accumulate. Some water naturally 

 contains a large amount of minerals and leaves a heavy deposit 

 in the boiler. The operator should learn to know the condition 

 of the water, and the frequency of cleaning the inside of the boiler 

 should be governed accordingly. One cleaning per month is 

 sufficient with most water. In some instances, one cleaning per 

 week is necessary. 



The collection of scale and sediment within the boiler affects 

 the economic operation in at least three ways: First, more fuel 

 is needed; second, the boiler itself is likely to warp; third, 

 foaming or priming of the boiler is likely to occur. If scale 

 clings to the flues when washed, it may be removed by putting 

 some sal-soda and water into the boiler and boiling for several 

 hours. Some use a boiler compound for preventing scales. 

 This is not necessary nor to be recommended except in extreme 

 cases where the mineral content of the water is very high. The 

 boiler should be frequently blown off at low pressure. 



Priming of Boilers. When considerable water passes over 

 with the steam the boiler is said to be priming. This water in the 

 steam interferes with the running of the engine, filling the engine- 

 cylinder and resulting in broken piston or cylinder-head. The 

 engine jerks and thumps to such an extent that there is danger of 

 breaking other parts of the machinery. 



The foaming or priming of boilers is due chiefly to: 



1 . Too much water in the boiler. 



2. Working the boiler beyond its capacity. 



3. Allowing mud and minerals to accumulate in boiler. 



4. Using too much of certain boiler compounds. 



