Substantiation of the operating parameters of walnut drying equipment

Abstract

The most important operation in walnut processing technology is drying to achieve the required moisture content. It is the most energy-consuming, and therefore, of course, there is an attempt to increase the energy efficiency of this process. Recent research and publications have shown many ways and means to dry nuts. According to the authors’ developments, the most effective are convective dryers, which can intensify the process by vibrating the material layer, which increases the heat transfer ratio. To determine the rational parameters of the drying process, a mathematical model was developed in which the nut is represented by a complex geometric shape – a sphere in a sphere, where the kernel is the inner sphere, and the shell is the outer sphere. The presence of harmful internal heat sources modeled the process of moisture removal. An equation was obtained in the criterion form that allowed temperature determination at an arbitrary point of the inner sphere at an arbitrary time depending on specific initial and boundary conditions, as well as the operating parameters of the drying process. The obtained mathematical model made it possible to reliably simulate the process of drying walnuts in a convective-vibration dryer and control the change in material temperature to ensure the high quality of the final product.