Energetics and Kinetics of Plant Raw Material Dehydration Processes

Abstract

The aim of this work is the energy-efficient equipment creation for production of a highquality dry product from a plant raw material and development of scientific and engineering foundation for the design of such an equipment. The achievement of this aim lies in a deep analysis of tendency in the development of a drying theory and technique. The graph is presented, on the basis of which the development of heat and moisture transfer model of A.V. Lykov is given, taking into account the P. A. Rebinder moisture bond forms specificity. The problems of convective drying modern technologies are determined; the reasons of high-energy consumption during their work are substantiated. The electrodynamic dehydrators classification is given, which considers the combined simple modes (drying) and hybrid dehydration modes. On the basis of the first law of thermodynamics, the possibility of a significant decrease in energy consumption is shown by the organization of a “vapordynamic” effect. The most significant result of the work is the construction of the electrodynamic apparatus module for dehydration of food and medicinal plant raw material. By the combination of electromagnetic field with the filtration process the specific energy consumptions were 1.9 MJ per 1 kg of the removed moisture, at the hybrid processes — juice yield exceeded vapor yield by 3.5 times. The significance of the work consists in the fact that the scientific conception of the authors on the possibilities of the significant decrease in energy consumption during the raw material dehydration at the innovative electrodynamic type apparatuses was practically proven

Study of the features of modeling microwave vacuum evaporation

“…The heat fluxes Qst, QV and the change in the internal energy of the body are determined according to the recommendations, for example [27] (2…”

“…The system of equations (6)(7)(8)(9)(10)(11)(12)(13)(14) describes a non-stationary temperature field, as well as material and energy balances in the evaporation process. For a more detailed system description, specification is required, including the addition of initial conditions and coupling equations.…”

“…For such special evaporation conditions in an electromagnetic, microwave field, the following key process parameters are proposed. These parameters follow from the proposed model (6)(7)(8)(9)(10)(11)(12)(13)(14), concretized considering the formulated hypothesis, and are presented in Table 2. Microwave field power…”

“…Concentration of the product by removing water is one way. This can be done through evaporation, freezing, and membrane separation methods [4][5][6][7]. Nevertheless, membrane methods are often used only for cleaning products.…”

“…Freezing allows to preserve the original product properties [8]. Block freezing is one of the new directions [7,[9][10][11]. Evaporation is the most common concentration method [12,13].…”