АЛГОРИТМ ПРОЕКТУВАННЯ АВТОМАТИЗОВАНИХ ЗМІШУВАЛЬНИХ КОМПЛЕКСІВ БЕЗПЕРЕРВНОЇ ДІЇ ДЛЯ СИПКИХ МАТЕРІАЛІВ

Purpose. Creation of design algorithm of continuous action mixing complexes that will allow defining parameters of the equipment proceeding from requirements to quality, productivity and the set compounding of mixture.Methodology. The method of discrete elements, classical mechanics positions, theory of solids contact interaction, method of mathematical modeling are used in the work.Findings. The paper proposes a generalized algorithm for designing a continuous mixing complex for bulk materials. The procedure for designing a centrifugal mixer, the flow shapers, plate feeders and conical-cylindrical hoppers are presented. Calculations of design and technological parameters are carried out on the basis of information about the physical and mechanical properties of bulk components particles, requirements for equipment performance and the mixture homogeneity. The results of calculations of the mixing complex for the three-component mixture used for the production of polyethylene film are presented. To test the proposed algorithm, a mathematical model based on the discrete elements method is created. The mixing process is modeled and the coefficients of inhomogeneity of each of the components in the finished mixture are determined. The obtained results confirmed that the proposed algorithm allows to determine the parameters of the mixing complex, which ensure compliance with the specified requirements for the quality and the equipment performance.Originality. Mathematical models of bulk motion dynamics in mixing complexes are improved, which include bunker devices, plate feeders, flow shapers and continuous centrifugal mixer, taking into account the bulk motion discrete nature.Practical value. The obtained results allow calculating the design and technological parameters of the equipment that is a part of the continuous mixing complex according to the set productivity, recipe and requirements to the mixture homogeneity.

Research and Optimization Design of Mixing Characteristics of High-speed Centrifugal Mixer Based on DEM

Aiming at the special production process of an environmental protection building material, a new mixing equipment, high-speed centrifugal mixer, was designed. In this paper, the mixing characteristics of high-speed centrifugal mixer were studied by using discrete element method (DEM). By constructing the contact model and establishing the evaluation system, the mixing process was simulated and analyzed by EDEM software, and the mixing situation of the two raw materials in the centrifugal mixer was obtained. At the same time, according to the two important factors affecting the mixing results, the comparative experimental analysis was carried out under different conditions, and finally the optimization suggestions for the equipment were put forward.

Determining the loose medium movement parameters in a centrifugal continuous mixer using a discrete element method

The processes to form the compositions of loose materials in centrifugal mixers of continuous action have been considered. Based on the method of discrete elements, a mathematical model of the movement of particles in the rotor of the centrifugal mixer was built, taking into consideration their geometric and physical-mechanical parameters. To assess the extent of influence of these parameters on the nature of particle movement, a well-known mathematical model in the form of a system of differential equations was used, which was built on the basis of classical laws of mechanics. The process of mixing particles of two loose materials under different initial conditions of movement was modeled. The trajectories of individual particles along the bottom and side wall of the rotor were calculated. The results of the research reported here have established that the model built on the basis of the discrete element method makes it possible to improve the accuracy of determining the parameters of the movement of loose materials in the mixing zone. Calculations that involved this method show that the length of the particle trajectory is 2.9, and the movement time is 9 times greater than those calculated by the system of differential equations. The built and known mathematical models demonstrated the same nature of the distribution of components in the mixer. The value of the Pearson correlation coefficient between the calculated values of the coefficients of variation is 0.758. The best homogeneity is achieved by separating the flows of the mixture components and reducing the distance between their centers. The experimental study was carried out using a centrifugal mixer of continuous action with a conical rotor. Particle trajectories were constructed; it was established that the shape of the trajectory built by a discrete element method is closer to the experimental one. The results reported in this paper make it possible to predict the impact of the structural and technological parameters of the mixers of continuous action on the uniformity of the mixture

Development and research of centrifugal mixer for baby food

The study was carried out on two mixers of different designs: basic and developed. To evaluate and analyze the finished mixture, the method of high performance liquid chromatography was used. Taurine was used as a key component. The paper describes how the rational parameters of the mixer were selected, according to which recipes the mixture was prepared, and also how the final assessment of the effectiveness of the mixing equipment was carried out. The mixtures were prepared on the equipment according to three recipes. According to the first recipe, 81 experiments were carried out, with various parameters of the mixer operation, which helped to determine their rational value. For two different mixers, they turned out to be identical, so further mixing took place with the same parameters. Based on the data obtained, graphs of dependences were built, which clearly demonstrated the difference in the obtained values of the coefficient of heterogeneity. And they made it possible to judge the influence of each individual parameter. The developed mixer design showed a lower coefficient of heterogeneity in comparison with the base one. It did not exceed 10%, unlike the latter.