Improving the Mechanical-mathematical Model of Pneumatic Vibration Centrifugal Fractionation of Grain Materials Based on Their Density

This paper has substantiated the mechanical-mathematical modeling of the process of fractionation of grain material into fractions. It has been established that this could optimize the process parameters and would make it possible to design new or improve existing working surfaces of centrifugal separators. A mechanical-mathematical model of the pneumatic vibratory centrifugal separation of grain material by density has been improved. This research is based on the method of hydrodynamics of multiphase media. The improved mechanical-mathematical model takes into consideration the interaction between the discrete and continuous phases of grain material by introducing conditions of interaction at the interface of these phases. In the hydrodynamic modeling of the movement of the circular layer of seeds, the coefficient of dynamic viscosity of discrete and continuous phases was taken into consideration. It was established that the pneumatic vibratory centrifugal separation process parameters are critically affected by the circular frequency of rotation of the cylindrical working surface, the frequency and amplitude of its oscillations. As well as such process characteristics as the airflow rate, dynamic viscosity coefficient, the average thickness of a grain material layer, and the mean density of its particles. Rational values for the technical parameters of the grain material pneumatic vibratory centrifugal fractionation process in terms of density have been determined by using the improved mechanical-mathematical model. The amplitude and oscillation frequency of the working surface are in the ranges A=(35…50)·10–5 m, ω=15.0...15.6 rad/s. The circular rotation frequency of the working surface, ω=24...25 rad/s. The airflow rate, V=2 m/s. It was established that using the improved mechanical-mathematical model of fractionation makes it possible to improve the performance of a pneumatic vibratory centrifugal separator by 9 %. At the same time, the effectiveness of grain material separation could reach 100 %

Improving the Mechanical-mathematical Model of Pneumatic Vibration Centrifugal Fractionation of Grain Materials Based on Their Density

This paper has substantiated the mechanical-mathematical modeling of the process of fractionation of grain material into fractions. It has been established that this could optimize the process parameters and would make it possible to design new or improve existing working surfaces of centrifugal separators. A mechanical-mathematical model of the pneumatic vibratory centrifugal separation of grain material by density has been improved. This research is based on the method of hydrodynamics of multiphase media. The improved mechanical-mathematical model takes into consideration the interaction between the discrete and continuous phases of grain material by introducing conditions of interaction at the interface of these phases. In the hydrodynamic modeling of the movement of the circular layer of seeds, the coefficient of dynamic viscosity of discrete and continuous phases was taken into consideration. It was established that the pneumatic vibratory centrifugal separation process parameters are critically affected by the circular frequency of rotation of the cylindrical working surface, the frequency and amplitude of its oscillations. As well as such process characteristics as the airflow rate, dynamic viscosity coefficient, the average thickness of a grain material layer, and the mean density of its particles. Rational values for the technical parameters of the grain material pneumatic vibratory centrifugal fractionation process in terms of density have been determined by using the improved mechanical-mathematical model. The amplitude and oscillation frequency of the working surface are in the ranges A=(35…50)·10–5 m, ω=15.0...15.6 rad/s. The circular rotation frequency of the working surface, ω=24...25 rad/s. The airflow rate, V=2 m/s. It was established that using the improved mechanical-mathematical model of fractionation makes it possible to improve the performance of a pneumatic vibratory centrifugal separator by 9 %. At the same time, the effectiveness of grain material separation could reach 100 %

Determining the Effect of Formulation Components on the Physical-chemical Processes in a Semi-finished Flour Whipped Product Under Programmed Changes in Temperature

The method of a differential thermal analysis has been applied to investigate the physical-chemical and chemical processes that occur in a semi-finished whipped flour product under conditions of a programmed change in temperature. Qualitative assessment of the processes that take place in the examined samples during thermal transformations has been performed.We have explored the influence of formulation components of a semi-finished whipped flour product on mass losses, the rate of transformations, and the dehydration processes occurring under non-isothermal conditions at a constant heating rate of 10±1 °C/min while heating up to a temperature of 300 °C.Synergetic interaction between xanthan and gelatin has been confirmed. It was established that the introduction of a xanthan solution to a gelatin solution, the base of a semi-finished whipped flour product, improves structure and enhances its thermal stability during heating. It is likely that this occurs due to the redistribution of associated and non-associated hydroxyl groups, which contributes to forming a large number of inter-molecular hydrogen bonds.We have proven the catalytic effect of the enzyme transglutaminase in the system gelatin-xanthan on the interaction between the amino groups of lysine and the γ-carboxyamide group of glutamine residues bound by a peptide bond. This effect ensured a higher level of crosslinking the macromolecules of a protein framework and substantially slows down the dehydration process in a semi-finished whipped flour product.Our study has established minimum losses of the adsorption-bound moisture in semi-finished whipped flour product, which is likely due to an increase in the degree of binding the groups of -ОН and flour proteins, which predetermines the formation of intermolecular hydrogen bonds with the proteins of a gluten complex.The influence of xanthan, sugar, transglutaminase enzyme, flour, on the ranges of dehydration has been investigated, which depend on different forms of moisture binding in a semi-finished whipped flour product. We have determined the temperature intervals of moisture loss at different shapes and binding energy in a semi-finished whipped flour product.The results obtained have practical significance for establishing the rational temperature conditions for baking a semi-finished whipped flour product, namely 140±5 °