Development of the technology of using mechanically activated microgrinded coals for firing and lighting of coal boilers of acting thermal power stations

A new technology of using the microgrinded coals in power boilers as well as the results of experimental studies and numerical modeling of microgrinding processes, preparing the air-dust mixture, and combustion of mechanically activated coals are presented. Pilot combustion of microgrinded coals on a firing stand with a power of 5 MW using disintegrator mills showed the possibility of reaching the stable autothermal combustion mode for coals with various degrees of metamorphism. Using mathematical modeling, the design solution for a two-step burner, which provides a stable high level of temperatures of the air-dust mixture at the output from the second step as well as makes it possible to minimize the cost for the production of mechanically activated coal, is suggested. These results indicate the possibility to develop burners intended for using mechanically activated coal, involving the replacement of the highly reactive liquid fuel used for firing the combustion chambers.