Introduction. In the process of convective drying, there is a contradiction between drying speed and energy efficiency. One of the solutions to this contradiction is the use of targeted energy supply ...to the product. The method of targeted energy supply is the use of electromagnetic radiation in the drying process.
Aim of the Article. The study was aimed at obtaining the coefficients of a logarithmic model for calculating the performance of a belt IR dryer for drying carrots.
Materials and Methods. There were studied a modular belt IR dryer with the ability to control the speed of the belt and the power of the emitters. To describe the process, there were used standard models of the dependence of relative water content on drying time.
Results. An analysis of the drying rate curves showed an extreme effect of the belt speed on the drying rate. At belt speeds above 10 mm/s, an increase in belt speed leads to an increase in the duration of the drying process. To describe the kinetics of the drying process at IR powers of 170, 300, and 450 W, there was used a logarithmic model, as it most adequately describes the experimental data.
Discussion and Conclusion. For this type of dryers it is recommended to use the belt speed of about 10 mm/sec. The obtained coefficients of the logarithmic model are used to calculate the capacity of the drying unit.
Introduction. The production of modern technologies should take into account a comprehensive analysis of energy, biotechnological and thermophysical phenomena. The main processes in food technologies ...are the processes of heat and mass transfer, which need to be intensified.
Aim of the Article. The aim of the work is studying the mechanisms and modeling the kinetics of heat and mass transfer in the microware field in the technologies for complex processing of food raw materials.
Materials and Methods. The combination of thermal, hydrodynamic and diffusion driving forces with their coordinated action is able to solve problematic issues of processing raw materials, primarily food. Using the principles of the similarity theory, there is proposed a dimensionless complex – the number of energy action, which reflects the influence of the electromagnetic field.
Results. Direct, targeted energy supply to the liquid phase of raw materials makes it possible to obtain a solid phase in the apparatus. These are fundamentally new features for the dehydration process. Boil-off rates at constant electromagnetic field intensity depend only on the solvent type. As a result of processing all experimental points, a criterion equation was obtained, it establishes the dependence of the energy action number on the dimensionless pressure and the dimensionless heat of the phase transition.
Discussion and Conclusion. There are developed a new class of heat and mass exchange equipment ‒ electrodynamic apparatuses. The experimental results suggest that the flow from capillaries and nano-capillaries is initiated much faster when organizing the processes of targeted energy delivery with the involvement of pulsed microware field. An important advantage of electrodynamic extractors is the possibility of obtaining polyextracts. Food technologies with targeted energy delivery during evaporating, drying and extracting are resource- and energy-efficient and ensure full preservation of raw material potential.
Introduction. At present, the issue of production of health-improving dairy products is topical. The aim of the research is to develop the technology of producing dairy with a disired consistency, ...balanced in vitamins, enriched with microelements and antioxidants and to optimize the parameters of pasteurizing and crushing pips to prevent the shell particles into the product.
Materials and Methods. The object of the study is the technology of producing therapeutic milk-based product, the processes of pasteurization of milk and crushing of the ziziphus component without damaging the stones. For this purpose, it is important to choose the optimal design-mode parameters of the crusher. The methodology of the experiment on the rotary crusher consisted of controlling the rotor speed and the gap between the movable and not movable ribs of the crusher. We proposed a design scheme allowing crushing fruits without damaging the stone.
Results. The obtained data allowed us to formulate recommendations for optimizing the temperature of pasteurization of raw milk materials in terms of forming the specified rheological properties. It is suggested to use pectin-containing ziziphus fruits to form necessary consistency of yogurt (kefir). The kinematic parameters of the device for crushing ziziphus fruits without damage to the stones have been determined.
Discussion and Conclusion. The analysis of the product viscosity dependence on pasteurization temperature shows that the maximum product viscosity is obtained at pasteurization temperature 81–85 °C. To prevent the destruction of the shells of the stones when separating the pulp, the speed of the crusher ribs should not exceed the characteristic speed of the stones, that is in the range from 4.5 to 10.5 m/s.
Introduction. Currently, the issue of reducing electrical energy consumption in the technologies of processing agricultural products, in particular, milk is topical. In large part, these costs are ...associated with the implementation of heat treatment processes. The reduction of electrical energy consumption can be achieved in several ways, one of which is the development and application of solar-powered installations. In this case, the consumption of traditional electrical energy is significantly reduced, but the manufactures have the task of coordinating the installation parameters and the real production conditions of enterprises.
Materials and Methods. The study examined energy consumption in milk processing technologies, plate heat exchanger operation modes and heliocollector performance indicators. The heating temperature of the coolant and the product was determined with an instrument complex that allows registering the temperature values in 8 different control points and transmitting the received signals to the personal computer hard disk. The method for defining the parameters of the plant for preparing the coolant in the technologies of milk processing with the use of a complex energy-substituting unit is proposed. The new technique provides a reduction of electric energy consumption from 30 to 70%.
Results. The consumption of electrical energy for thermal processes can be reduced by using solar energy. To solve the problem of optimizing the ratio of product consumption, heating area in the heat exchanger, the area of the solar collectors of the energy-substituting installation, it is recommended to use the obtained graphical dependencies and the formula for determining the area of the solar collectors.
Discussion and Conclusion. It is possible to determinate the area of solar collectors of complex energy-substituting installation for real production conditions through using the obtained analytical dependence taking into account the dependence the specified parameter on a temperature mode of heating, the area of a surface of heating in the heat exchanger, and weight of milk being processed per unit of time. The obtained graphical dependencies make it possible to determine the product consumption and heating area for the given heating temperature values.
We present our last results on anomalous Hall effect (AHE) in (Co41Fe39B20)x(Al–O)100-x nanocomposites focusing on the possible correlation between temperature dependence of AHE and resistivity. It ...is shown that the temperature dependence of conductivity G=1/Rxx, where Rxx is resistivity, for compositions with x=49-56% at 10K<T<Tk follows the relation, where the parameters A, , Tk depend on x. For x=47% this relation changes to the exponential law “1/2” Rxx ∝ exp (Т0/T)1/2. The correlation between AHE resistivity RH (T) and resistivity Rxx (T) can be described as RH ∝ (Rxx)m , where m increases from 0.38 to 0.58 with an increase of x from 49 to 56 %.
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