72 



Indiana University Studies 



Cost of Boiler Settings. 



cost of boiler settings: 



Gebhardt gives the following 



Horizontal water-tube: Cost equals 400 + 0.8 X rated horse-power. 

 Return tubular: Cost equals 300 + 0.7 X rated liorse-power. 



The only form of stack in use in the district is the guyed steel 

 stack, and for all kinds of service it is the best as well as the 

 lowest in first cost. There is a tendency here, as elsewhere, 

 not to allow sufficient draft to burn properly the coal on the grate; 

 and a large loss of coal is the result. Any unburned gases that 



ti: 



1?£ 



t.zhr. 



mi 



0 



U6 



IT, 



Ml 



99$ 



2ZQ 



Plot 2 gives the approximate cost of boilers and is taken from the same source 

 as Plot 1 (p. 89). 



escape from a chimney are money out of the owner's pocket. 

 The best practice is to have ample draft and control it by dampers, 

 instead of running the risk of having insufficient draft in unfavor- 

 able weather. Ordinarily the draft should be one-third more 

 than enough for the usual run in order to give a sufficient draft 

 for overloads or times of poor draft. The breechings should be 

 large and free from obstructing turns or unnecessary dampers. 

 Lack of adequate draft can more often be traced to defective 

 breechings than to lack of stack capacity. 



The most reliable method of boiler feeding is by means of a 

 direct-acting single pump. A second pump or an injector should 

 always be held in reserve. The single pump is usually superior to 

 the duplex pump because the single pump is far more economical 

 of steam and has fewer parts to keep in running order. In all 

 duplex pumps each steam piston is controlled and reversed by a 



