Grain drying in pneumatic transport mode

In the pneumatic conveying of grain material there is such a concept as "choking speed", indicating the environment speed, at which the flow is saturated with material and there comes a violation and termination of the system - the grain stops moving in a set direction. At pneumatic conveying it is profitable to work with the minimum velocity of conveying air, due to which the least energy consumption for transport is obtained, and the erosion of the working chamber is reduced. We propose the construction of a grain dryer with fluidization of the grain layer and simultaneous pneumatic conveying from the hopper to the outlet pipe. The working chamber of the dryer consists of drying and cooling parts. The drying part is a pneumatic groove with inclined walls, located above the gas-distributing grid on the size of the gap required for the circulation of grain material. During the drying process, the temperature of a single grain does not increase constantly, but along a wavelike curve. The maximum values of grain heating alternates with minimum values, but the maximum ones are gradually increasing. The overall curve of grain heating is an averaged curve between the maximum and minimum values. We studied the drying of grain material by method of recirculation with oscillating mode, which allows by alternating the cycles of heating-cooling of grain to prevent overheating, preserve food and sowing qualities.