Influence of Grinding Methodology and Particle Size on Coal and Wood Co-Combustion via Injection Flame Opening Angle

Abstract

Today, more than 61% of the world’s electricity is generated by burning fossil fuels. The search for reducing the negative impact of such thermal power plants on the environment does not stop for a minute, one of the solutions to this problem is the partial replacement of coal with biomass. This method has proven itself most effective over the past five years. Co-pulverized combustion of coal and biomass has not found wide practical application, since the processes of grinding, mixing and subsequent spraying of such mixed fuels have not been fully studied. This study compares the influence of the method of grinding, mixing coal and biomass on the processes of spraying mixtures with a change in the pressure of the atomizing air. The results of the research showed that the joint grinding of coal and biomass contributes to the achievement of the minimum size of coal and wood and, as a result, leads to an increase in the opening angle of the torch, which will significantly improve the efficiency of flame combustion in the furnace space at the station. The most effective spray pressure of the mixed fuels was established, which was 3 bar. An analysis of the results obtained during the course of the research allows us to conclude that the mixing of coal and sawmill waste, followed by joint grinding in a ball mill, contributes to the effective grinding of biomass and coal particles to a finely dispersed state, which subsequently leads to a significant increase in the opening angle of the torch at any concentration of the mixture composition fuels.