84 ILLINOIS ACADEMY OP SCIENCE 



coke or anthracite it is often customary to make fuel 

 charges of perhaps 700 or 800 pounds at a time in a 6 ft. 

 set and after cleaning the fire it is often the practice to 

 make double or even triple charges to build the fuel bed 

 rapidly up to the proper operating depth. If this pro- 

 cedure is followed with bituminous coal, within an hour or 

 so the caking of the coal has progressed to such an extent 

 that an arch of partially caked fuel, almost impenetrable 

 to the air blast, is formed. The result is that the rate of 

 combustion is greatly slackened, the fuel bed becomes 

 relatively cold, and the gas-making reactions of the steam 

 run are also slackened. Under these conditions the rate 

 of production falls far below that ordinarily obtainable 

 with coke. The only remedy for this condition after it has 

 taken place is to break up the caked fuel frequently, with 

 heavy iron bars, a laborious time-consuming operation. 

 The remedy applied at Streator and elsewhere was to avoid 

 all double fuel charges and rather make the charges 

 lighter and more frequent at the start until the fuel had 

 been brought up to working depth. By this procedure 

 barring the fire could be entirely avoided. While the rate 

 of gas production was increased, it did not equal the pro- 

 duction with coke, and a method developed at Streator for 

 increasing production will be discussed a little later. 



The smoke problem was also one which caused much 

 concern to the gas operator, but especially to other estab- 

 lishments located in proximity to the gas plant. Water- 

 gas sets do not usually have high stacks which dissipate 

 smoke in the upper atmosphere. The combustion products 

 are usually expelled just above roof level; consequently 

 near neighbors get the full benefit when smoke is pro- 

 duced. The greatest difficulty was experienced after the 

 machine had been idle for several hours and the fuel bed 

 and checkerwork had cooled somewhat. If a charge of 

 fresh coal were added to the fire and the blast commenced, 

 the blast gas produced in the generator at first would not 

 be rich enough to burn upon the addition of secondary air, 

 or if it were the temperature of the checkerwork might be 

 too low to ignite it. As a result, the tar vapors formed 

 from incomplete combustion of the coal would pass 

 through the carburetor and superheater unconsumed, and 

 even the pilot light kept constantly burning at the stack 

 would only partially ignite them if at all. The result was 



