Effectiveness of Biomass Pellet Parameters on Their Fractal Dimension

Abstract

In order to perform quantitative analysis and predict the wear of the forming channel, this study makes biomass pellets as experimental samples. The surface morphology was scanned by a scanning electron microscope (SEM), and the surface morphology data and images were collected by a roughness instrument. Then, we collected the data of arithmetical average deviation Ra, density ρ, as well as hardness HD, and further calculated the fractal dimension D, which help to study the influencing factors of fractal dimension on the circular surface morphology of biomass pellet. The results show that, the density ρ and hardness HD of biomass pellets both decreased and with the increase in diameter d, the arithmetical average deviation Ra increased with the diameter d, the quality of the pellet is reduced, meanwhile, the fractal dimension D also shows a downward trend. Using the value, trend of fractal dimension D to analyze the quality of biomass pellet can predict the wear status and life of forming channel in biomass briquette machine. It is concluded that, the fractal expression of surface morphology in biomass pellet relates to inner surface morphology of forming channel in biomass pelleting machine. Additionally, fractal dimension of the surface morphology of biomass pellet can be the basis of preliminary research for friction and wear detection and prediction of forming channel.