When the rollers run on the layered coal , Effect of particle size distribution on the friction characteristics

Abstract

Coal-fired power plants are responsible for about 40% of electricity generation in the world, and it is expected that the energy demand will be large in the future and will be playing a leading role in energy. So, it has become important to grinding a large amount of coal in the vertical roller mill. However, there is a problem that self-excited vibration occurs when pulverizing coal. We believe that it will occur when powder characteristics and pulverization conditions become specific conditions. Therefore, in this report, we examined the relation between particle size distribution and abnormal vibration by changing the particle diameter ratio, which is one of the powder properties, by rolling experiment. As a result, it was found that the vibration characteristics change when the particle diameter ratio changes. In addition, abnormal vibration was confirmed at a certain ratio, and it was found that there was dependency on the friction characteristics and the degree of slippage.