ОСНОВНІ ПІДХОДИ В ДОСЛІДЖЕННЯХ ТЕРМОМЕХАНІЧНИХ ПРОЦЕСІВ ПЕРЕНЕСЕННЯ ПОТЕНЦІАЛУ ТЕПЛОТИ І МАСИ ПРИ СУШІННІ ХАРЧОВИХ ПРОДУКТІВ.

І. М., Ощипок

The article develops the thermo-moist mechanics of drying food products based on systems of differential equations of heat and mass transfer and describes various such processes. The task of improving the process of thermal drying of products in the forced mode is considered, which consists in determining the relationships between the process parameters: the temperature of the drying agent at each stage, the exposure time, the initial drying temperature and the initial and final moisture content of the product, which will allow without reducing the quality of the finished product product to carry out the process with the minimum total drying time with minimum energy consumption. Adsorption and desorption isotherms of water in food products, which depend on water content and temperature, were constructed. The desorption curve is shown, which is divided into 3 zones. Zone 1 (0 ≤ 0.2): characterized by the formation of a molecular monolayer on the surface of the product (van der Waals forces between hydrophilic groups and water molecules). Zone 2 (0.2 ≤0.6): Adsorption of hydrogen molecules occurs on the initial monolayer or by the inclusion of water molecules by capillary action. Zone 3 (> 0.6): water present in a liquid state in the pores of the material. Microcapillary water is the continuous phase. This evaluation of the application of the diffusion theory model for biological materials governed by the diffusion equation. In this context, the position of the theory of capillarity, in which the flow of moisture is determined by capillary forces, and not by the moisture concentration gradient, was studied. On the basis of the evaporation-condensation theory, evaporation and condensation were considered as a connecting mechanism of mass transfer and internal heat, where the mass goes into a vapor state, and heat is exchanged with the environment by condensation of steam or evaporation of water. The mechanisms of moisture transfer inside food products in the form of a solid body are shown.

VAN der Waals forces; DRYING agents; MASS transfer; FOOD dehydration; HEAT equation; DRYING

Scientific Works, 2024, Vol 87, Issue 1, p99

2073-8730

Academic Journal

10.15673/swonaft.v88i1.2967