Design On Hot-blast Drying System Of Biomass Briquetting Fuel And Experiment Of Drying Dynamics

There are very abundant crop straw resources in China. Without reasonable treatment, many of them have been wasted and result in serious problems. The crop straw has the advantages of high quantity, less pollution and renewability, it can be briquetted also then be used as fuel blocks. At the same time, in rural areas, drying mainly depends on the direct sun which occupies many areas because of natural limitation. Many data indicated that provision loss reaches to 5% because of not drying on time. It is the background of this article. In this article, the hot-air stove using straw molded briquitting fuel has been designed and the performance has been tested. Its heat efficiency reaches 49.5%, which indicates that the stove structure is reasonably designed. The hot-air stove is easy to make and convenient to operate. The related drying apparatus is designed also. And we did experiment of drying on it which showed that the designed drying system meets the necessity of the coin drying characteristic and is suitable to do the drying test. We have done drying dynamics experiment and analyses of the coin, soybean, the peanut in different original water containing rate. Under different temperature and the hot-air speed, according to the drying curves, they have shown that the most notable factor influencing the drying speed and drying quality is air temperature, air speed sits secondly. Models which can be used to describe the maize thin-layer drying are: exponential model, single entry diffusion model and Page model have been selected. The related three models equations and the corresponding parameters have been defined. From the comparison among the actual data and the significance check of regression equation, it has been discovered that the single entry diffusion analogue effect is the best, the Page equation analogue effect is better, especially during the speed reduction drying process. Due to the heat sensibility of the things to be desiccated, it requires strictly of the quality after drying, especially the seed drying, because when temperature is higher than 60°C,the rate of kernel cracking increases greatly. In that case, the drying process should be separated and the reasonable drying craft must be selected which provides the basis for the afterward design of the drying equipment.