WAYS TO INCREASE THE INTENSITY OF THE WALNUT DRYING PROCESS

Drying is the most important process in the processing of plant products, including walnuts. Convective heat dryers are the most common in agriculture due to their high energy efficiency, relative simplicity of design and reliability in operation. Modern serial convective dryers consume 5-7 times more energy than an "ideal" dryer. Intensification of the drying process can be carried out in two main ways – by increasing the temperature difference between the drying agent and the material and improving the heat exchange conditions between them. When drying walnuts, the most acceptable way is to increase the heat exchange coefficient between the coolant and the nuts. To accomplish this goal, the authors suggest applying a vibrational effect to a layer of nuts. The versatile direction of the vibration action makes it possible to reduce the aerodynamic resistance of the layer, increase the contact area of the material and the drying agent, and turbulize the boundary layer between them. To implement the presented provisions, a fundamentally new structural and technological scheme of a convective-vibration dryer was proposed. The innovative approaches used in its functioning made it possible to improve the quality indicators of walnuts in the process of storage and processing. The use of a complex convective-vibration method of drying walnuts made it possible to reduce the value of energy for the evaporation of 1 kg of moisture to 3.9 MJ compared to 5-6 MJ for modern serial dryers. The results of the production inspection confirmed the correctness of the proposed approaches. Further research in the intensification of the convective-vibration dryer should be aimed at determining the rational parameters of the vibration effect, choosing a compromise solution between the costs of implementing vibrational vibrations of the walnut layer and the energy spent on their creation.