Rice Flat Bed Desiccation Pilot Study

The mechanization in cultivation and harvest of grains has been mostly realized in main regions of cereal production, but there has been scarcely mechanization in drying of harvested grains. Because the harvested cereals could not be dried immediately, millions tons of grains were wasted each year. Therefore, farmers eagerly require for grain dryers which are cheap and effective and can be used in variant conditions. In this study, a drying installation, which was made of planks, a ventilating fanner, ventilating boards and a burning device etc., was installed firstly, and then eight experiments were carried Out to research characteristics of the, dryer and deep-thickness drying properties of paddy. The results showed that wind velocities, paddy temperatures and paddy moisture water contents along the face of fixed-bed were unanimous and the temperature and moisture content of paddy changed with the layer thickness. The relationships between average temperatures of paddy and drying times could be described as following: 鰚 =at2+bt+c The paddy being layered occurred in drying processes. As the layer thickness was high, moisture contents of the paddy at bottom layer fallen a lot, the one at middle layer reduce slowly and the one at face layer changed a little. If only a simple average moisture content of paddy on the fixed-bed was necessary to take into account, following equation could be established by regression analyses: Ru = Aexp(梑t) The paddy cracking additional percent was effected by wind temperature and moisture content of dried paddy. It inclined to rising with increasing in the wind temperature. The bad drying of paddy could bring about sharply increasing in crack rate. However, keeping the moisture content of dried paddy from dropping below 14% would avoid to such a case occurring.