RI 2943 Tests of Bituminuous Coking Coal

"Wien bituminous coal is burned in a hand-fired up-draft boiler used for heating purposes it has a decided tendency to produce smoke. A design of furnace and a method of firing and attendance that are satisfactory for fuels low in volatile matter, as anthracite or coke, are not necessarily Satisfactory for bituminous coals. It is therefore becoming common practice to use a special design of furnace for bituminous coals, in order to facilitate the combustion of the volatile matter and soot. This is done by (1) providing a larger combustion space to give more time for the combustion, (2) construction that will produce a better mixing of the gases and secondary air supplied over the fuel bed, or (3) keeping the gases at a higher temperature by preheating the secondary air, as may be done by surrounding them with refractory surfaces, or causing them to pass through a fuel bed of hot coke. A furnace may be built to use any or all of these methods of smoke prevention.In Bureau of Mines Technical Paper 303, Blizard5 and others give tests on a large heating boiler when burning coke, anthracite, and bituminous coal. Certair alternative furnace arrangements were used, but there was no material change in the furnace design for the various fuels. Since that time the manufacturer has made modifications in design to adapt it for use of bituminous coal, and additional tests have been made to determine how this change affected the production of smoke and the efficiency of the boiler."