FLAT SIEVE SEPARATORS WITH ANNULAR PNEUMATIC SEPARATION DUCT

The search for the optimal variant of the structural ar-rangement of flat-screen separators by centrifugal-air sepa-rators with annular pneumatic separation ducts is a promis-ing direction in the development of new equipment. This will significantly improve the technological performance of grain cleaning plants. It may be considered a promising direction for such research. Therefore, it is necessary to look for new options for the layout of grain cleaning ma-chines to increase their technological efficiency. Several variants of technological schemes for the operation of ex-isting flat-sieve separators with a centrifugal-air separator with an annular pneumatic separation ducts are proposed. The technological process of the modernized grain clean-ing plant based on the A1-BIS-100 plantis described. The main parameters of the gravity transporting device are de-termined; they fully ensure the operability of the modern-ized plant.

Numerical Study on the Influence of Length-Diameter Ratio on the Performance of Dynamic Pressure Oil-Air Separator

In order to study the separation characteristics of the aeroengine dynamic pressure oil-air separator, this paper uses the coupling method of PBM and CFD two-fluid model to study the influencing factors such as cylinder diameter, cylinder length, and other factors on the separator performance. The flow field structure, velocity, gas volume distribution, separation efficiency, and gas and liquid holdup rate in the separator under different operating conditions are analyzed. Combined with the analysis results of the cylinder diameter and the cylinder length, the influence law of length-diameter ratio on separation efficiency is summarized. The optimum length-to-diameter ratio that maximizes the separation performance of the separator is obtained in this research, which provides a reference for the design and improvement of the separator. The results show that, as the diameter of the cylinder increases, the separation efficiency increases first and then decreases. When dsep = 16 mm and dsep = 18 mm, the separator reaches its maximum efficiency, which is about 93%. With the increase of the cylinder length, the separation efficiency first increases and reaches the maximum when l2 = 90 mm and then decreases slowly. When the separator cylinder is either too long or too short, it will cause the separation performance to decrease. There is an optimal aspect ratio. There is an optimal aspect ratio, and the separation performance of the separator is the best when the aspect ratio is between 5 and 6.

Performance Prediction Model of Dynamic Pressure Oil-Air Separator

Based on the aeroengine lubricating oil system test bench, this paper used a dimensional analysis method to establish a mathematical model for predicting the separation efficiency and resistance of a dynamic pressure oil-air separator suitable for engineering. The analysis of the multivariate nonlinear fitting error and the experimental data showed that the established separation efficiency and resistance model could accurately predict the separation and resistance performance of the dynamic pressure oil-air separator within a certain range; the average error of the four separation characteristic prediction models was 3.5%, and the maximum error was less than 16%. The model that was established by the least square method had the highest accuracy; the average error of the multivariate nonlinear fitting of the four resistance characteristic prediction models was less than 4%, and the maximum error was less than 15%, which could be used to predict the resistance performance of the separator. The applicable working condition of the model is lubricating oil flow rate 4.3~8.5 L/min and oil-air ratio 0.5~3.

MATHEMATICAL MODELING OF PROCESSES OF SEPARATION OF COMPONENTS OF GRAIN MATERIAL IN THE COMBINED VIBRATION-AIR SEPARATOR

Development of a mathematical model and calculated analytical dependencies for determining the trajectories and parameters of grain movement in a vibro-fluidized layer of grain material components under the action of a pulsating air flow. They are based on the methods of deterministic mathematical modeling and theoretical mechanics based on the equations of motion of a material point at a variable air flow speed and the action of a pulsating air flow. Theoretical studies were carried out using the methods of mathematical analysis and modeling. The research results were processed using elements of the theory of probability and mathematical statistics using software packages; to determine the rational parameters of the process, the method of statistical experiment planning was used. A mathematical description of the motion of the grain material particles in a combined vibration-air separator under the action of a pulsating air flow of variable speed is given. The trajectories of motion of particles with different sizes are obtained. The obtained equation of motion of a particle under the influence of a pulsating air flow makes it possible to determine the dependence of the speed of movement of the material in a vibro-fluidized layer of grain material on a number of factors: the geometric parameters of the sieve-free sieve, the feed angle of the material, the initial kinematic mode of the material, the index of the kinematic mode of the sieve-free sieve, as well as the coefficient of windage of the grain. On the basis of theoretical studies, the possibility of separating particles of grain material into fractions according to aerodynamic properties with vibropneumatic loading of grain into the channel has been determined. The use of a pulsating air flow as a separating carrier, and taking into account the deflecting forces, made it possible to significantly increase the splitting of the trajectories and the criterion for dividing the grain into fractions.

RDF from Compost-Like-Output’s Produced in the MBT Installation in the Case of Marszów, Poland

At most of the installations for the mechanical and biological treatment of waste operated in Poland, the 0–80 mm fraction, separated from the municipal waste stream, are completely stored after biostabilization. Such an action does not fit into the EU strategy focused on circular waste management. The purpose of this study was to assess the technical feasibility of recovering the mineral fractions contained in the compost-like-output (CLO) on a technological line designed for glass recovery. The research started in January 2019, lasted for the next 12 months, and covered 29 measurement series. The following two high-energy fractions were separated from the CLO: 10–35 mm light fraction after separation in the air separator (M-1) and 35–80 mm light fraction after separation in the air separator (M-2). The stabilization processing on the glass recovery line allowed for the recovery of two high energy fractions in the total amount of 24.5% of the processed, and it stabilized the product’s mass. In terms of materials, the M-1 and M-2 wastes were a mixture of organic, paper, and plastic materials. Under the Refuse Derived Fuel (RDF) classification, according to the European Committee for Standardization, the tested waste fell within the following classes: waste M-1: 4NCV2Cl4Hg and M-2: 4NCV1Cl4Hg.

Analysis of the influence of non-uniformity of air flow velocity on the trajectory of grain particles motion in a pneumatic inertial separator

Purpose. Determination of influence of non-uniform velocity field of air in horizontal channel of pneumatic inertial separator on efficiency of separation of components of grain material into fractions by aerodynamic properties. Methods. The specificity of the issue under consideration determines the analytical method of study based on the compilation and analysis of kinetic equations of motion of a particle, in the form of a ball in the air flow of a horizontal channel with uneven distribution of air flow velocity over the height of the pneumatic channel. Results. The mathematical description of the motion of particles of the grain mixture in the chamber of the gravitational-air separator under the action of air flow of variable speed air is given. The trajectories of motion of particles of different size were obtained. The obtained equation of motion of a particle under the action of air flow allows to determine the dependence of the speed of movement of the material in the layer of grain material on a number of factors: geometric parameters of the separator, the angle of feed of the material, the initial kinematic mode of the material, as well as the coefficient of sail of the particle. The technological possibilities of the proposed method of grain separation under the action of air flow are theoretically substantiated and the influence on the technological parameters of the basic parameters: air velocity, coefficient of live section taking into account the layer thickness of the material entering the channel is established. Conclusions 1.On the basis of the analysis of the force interaction of the grain material particle with the air stream, an advanced mathematical model of particle motion in a non-uniform field of air flow velocity in the horizontal channel was obtained. 2.The real possibility of controlling the process of separation of components of grain material by aerodynamic properties by changing the plot of the air flow velocity along the height of the horizontal channel is determined. Keywords: variable air velocity, trajectory, resistance of forces, fractions, air flow, wind factor, fractionation process, grain mixture, air separator.

Analytical studies of the technological parameters of the curved channel of the pneumatic separator

Purpose. Establishment of the laws governing the movement of particles in the air flow with an uneven distribution of flow velocity and the action of additional forces arising from this. Methods. Theoretical studies are based on the basic principles of theoretical mechanics, in particular dynamics, as well as the theory of differential equations of the first and second order Results. A mathematical description is obtained of the movement of particles of the grain mixture in the chamber of a gravity-air separator during the action of air flows of variable speed, as well as the trajectory of particles with different sizes. With certain assumptions, the obtained patterns of change in the velocity of a material particle (point) from coordinates. Conclusions 1.Based on theoretical studies, taking into account deflecting forces, the possibility of separating particles of grain material into fractions by aerodynamic properties in vertical channels and with a lower discharge is determined. 2.The use of air flow as a separating carrier can significantly increase the value of the splitting of the trajectories and the criterion for the separation of grain into fractions. 3.Created simplified mathematical models of the movement of the components of the grain material in air separators with vertical channels, which allow us to determine the rational modes of operation of new technical means. Keywords: air flow, variable air speed, trajectory, stability of forces, fractions, fractionation process, grain mixture, air separator, pneumatic circular flow.