The analysis of fuel, gas, water, and lubricants . oker boiler, showing tile baffling. aggregate this is more than that produced by factories and smallestablishments combined. In the case of large installations the conditions under (a) and(6) are the most readily provided through the use of stokerswhich avoid the intermittent conditions which accompany handfiring. A steady accession of fuel results in a uniform dischargeof volatile combustible, which can be met with reasonable accu-racy by a definite admission of air above the fuel. Varying loadsand varying draft pressures however complicate t
The analysis of fuel, gas, water, and lubricants . oker boiler, showing tile baffling. aggregate this is more than that produced by factories and smallestablishments combined. In the case of large installations the conditions under (a) and(6) are the most readily provided through the use of stokerswhich avoid the intermittent conditions which accompany handfiring. A steady accession of fuel results in a uniform dischargeof volatile combustible, which can be met with reasonable accu-racy by a definite admission of air above the fuel. Varying loadsand varying draft pressures however complicate the problem. The most difficult condition of all to meet is that under (c) or(b) and (c) combined. The ignition temperature of the morecommon gases discharged into the combustion chamber such as 68 FUEL, GAS, WATER AND LUBRICATION methane, for example, is from 650 to 750°C. or a mean of 700°C.(1,300°F.) and for hydrogen it has an average ignition tempera-ture of 585°C. or l,085° The temperature of the flues in a water tube boiler doubtless. Fig. 17.—Sectional view of stoker and boiler. never exceeds 200°C., (425°F.) at 300-lb. gage pressure.^ Amongthe more common methods for securing the necessary tempera-tures are those which provide a longer combustion may be secured horizontally, as in the tile baffling of the 1 Dixon and Coward, Jour. Chem. See, vol. 95, p. 519, Marks and , Steam Tables, Longmans, Green Co. COMBUSTION OF COAL 69 lower flues, Fig. 16, or by elevating the boiler above the fuel bed asshown in Fig. 17, where the extreme height between the fire andflues may average as much as 15 ft. A good illustration isshown in Fig. 18 of the effect of cooling the gases discharged fromthe fuel bed below the temperature of ignition before combustionis complete.
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectchemist, bookyear1922
