Experimental studies of the plant raw material drying processes in the conditions of infrared and microwave fields

Abstract

The object of research is the process of drying food plant raw materials. Among the existing methods of drying, convective has become the most common in industry, due to its practicality and ease of organization. However, modern convective drying technologies are accompanied by high-energy consumption, which is a serious problem in the conditions of global energy shortage. An analysis of options for solving drying problems proposed by the scientific community was carried out. The paper presents a solution to the problem through the use of electrodynamic dehydration technologies based on directed energy action. The principle of operation of such technologies is that the electromagnetic field directly interacts with polar molecules, which includes water, which leads to a significant increase in the energy efficiency of the drying process and a reduction in its duration. A set of experimental studies aimed at determining the effect of regime parameters, namely specific power, thickness of the product layer and type of edible vegetable raw materials on the drying process under the conditions of infrared and microwave fields, was carried out. The obtained graphic dependences indicate that the treatment of raw materials with ultra-high frequency radiation significantly reduces the time of the drying process and, as a result, is characterized by a low thermal load on the product, which is a significant advantage when processing heat-labile raw materials. This is due to the deeper penetration of the microwave field (up to 30 mm) compared to infrared (up to 0.003 m). In order to determine the effectiveness of innovative equipment, the paper presents the number of energy action, thanks to which a generalization of the experimental data base was carried out. As a result, criterion equations were obtained, which with an accuracy of ±16 % make it possible to calculate drying devices with infrared and microwave energy sources.