The Experimental Investigation For Pneumatic Drying Of Stalk Particles

Biomass burning causes lower pollution compared to coal, with no emission of carbon dioxide, which can effectively alleviate the greenhouse effect and the shortage of energy in China. The harvested fresh biomass fuel contains more moisture, so the ignition and stable combustion is difficult when burned in layer combustion boiler. Injecting a certain amount of grinding and drier biomass fuels into the top of grate can effectively solve these problems. To achieve a large-scale use of high moisture biomass straw in layer combustion, the research of biomass drying has practical significance.A large number of experiments had been done, in order to explore the drying regularity of straw particles, according to the physicochemical properties of common straw (corn straw, rice straw, etc.). The optimal dry conditions had been summarized, and the straw particles drying process had been simulated and analyzed.According to the experiment result, it showed with the length of change, the moisture content is reduced, and it was faster in the first half than the other; The result showed that the sequence of importance about the influences of the drying parameters on the dry velocity was following: Hot air temperature>feed rate>air volume> initial moisture content, while the sequence of importance about the influences of these dry parameters on the consumption of unit energy was obtained: feed rate > Hot air temperature > air volume >initial moisture content.Through the analysis of the characteristics of the drying process of biomass fuel particles, a numerical model to describe the heat and mass transfer process in pneumatic drying of biomass fuel particles in horizontal tube has been established, based on two-phase flow theory. This model is solved by numerical method. The experiment result shows that the model can reflect the actual drying process precisely.