Experimental Research on the Drying Characteristics of Flexible Fibrous Biomass Fuels in the Baffled-Rotary Cylinder

Drying was significant and challenging for wet nonspherical biomass fuels in the pretreatment process. In the study, a series of researches were conducted to determine the drying characteristics of flexible fibrous biomass particles. Cut rolled stems were taken as experimental materials due to their spreading application and structural features. Here, heat- and mass-transfer characteristics for flexible fibrous biomass particles were investigated under various drum temperatures, gas temperatures, velocities of gas flow, and rotational speeds. Moreover, the moisture content, temperature, and moisture loss rate of flexible fibrous biomass particles were calculated. The experimental results demonstrated that the drying capacity of biomass particles was counted through the temperature difference between the particles and the atmosphere. Thus, the high temperature of particles could reduce their drying capacity. Furthermore, the temperature and moisture content of the particles were greatly affected by the cylinder temperature and gas flow. The heat and mass transfer between the particles and the gas phases would be enhanced by large gas flow velocity, especially for mass convection. The exiting heat and mass characteristics of flexible fibrous biomass particles could provide valuable guidance to make further studies on other wet fuels with nonspherical structure.