Experimental Investigation of the Influence of Temperature, Coal Metamorphic Stage, and of the Size of Coal–water Fuel Drop on the Fuel Drop Combustion Process

The experimental investigation carried out allowed one to determine the influence of the source coal grade, oven medium temperature, and of the CWF drop size on time and temperature correlations characterizing the process of individual fuel drop combustion in static air. It has been established that shortening of the total time of CWF drops combustion related to the oven medium temperature increase and the drop size decrease is governed by a power function. In identical conditions, the time of CWF drops combustion is shortened significantly, when anthracite is replaced by the brown source coal. The research and processing of the obtained experimental data allowed establishing empirical dependences of the CWF drop combustion time on volatile content in the source coal, and on drops sizes, taking into account the oven medium temperature and the source coal grade. It was found that in the equation describing the dependence of the combustion time on the drops sizes the exponent of the size is equal to 1.6 and does not depend on the coal grade and oven medium temperature.