Purpose. Conduct numerical modeling of the process of bulk material separation under the action of air flow, vibrating sieve and solid vibrating surface in order to develop appropriate physical and mathematical models and to develop the proposed research methods.
Methods. The bulk material separation process was investigated in three stages of modeling in the STAR-CCM + software package by finite element method based on k-ɛ split-flow turbulence model, Van der Waals real-gas model, discrete element model and multiphase interaction model. The first step was to simulate the process of bulk material moving under the action of airflow. Separation of bulk material on a small-sized cyclone-type aerodynamic separator was investigated. Also, for the implementation of the first stage of numerical modeling, a computational diagram of the process of the falling particles moving under the action of air flow was compiled. The second stage was aimed at modeling the process of moving the bulk material under the action of a vibrating sieve. The task of the third stage of modeling was to determine the particle distribution function of the bulk material by fractions under the action of a vibrating surface.
Results. The numerical simulation of the bulk material separation process on a cyclone-type small-scale aerodynamic separator resulted in the mass distribution of components by volume mass at the outputs of heavy and light components on the effective particle diameter and air velocity. As a result of numerical simulation of the mechanical and technological process of the bulk material moving under the action of air flow, the dependences of the distribution of each fraction of particles of the bulk material along the length of the region (fill factor, distribution coefficient) on the effective particle diameter, air flow rate and flow of bulk material were obtained. As a result of numerical simulation of the process of the bulk material moving under the action of the vibrating sieve, the dependence of the change of the total concentration and productivity on the bulk material flow, the angle of the sieve, the frequency of oscillations of the sieve and the amplitude of oscillations of the sieve are obtained. As a result of numerical simulation of the process of the bulk material moving under the action of the vibrating surface, the dependences of the change of the filling factor, the distribution coefficient and the productivity on the bulk material flow, the angles of inclination of the vibrating surface, the oscillation frequency, the amplitude of oscillations and the airflow velocity are obtained.
Scientific novelty. The general coefficients of technological process quality in separation of bulk material (coefficients of filling and distribution and total concentration of seeds) are offered. The article obtains the mathematical models of the technological process of precision separation of the bulk material by its aerodynamic properties, geometric dimensions, bulk mass, which describe the change of the proposed quality coefficients depending on the regime parameters.
Practical importance. The obtained dependencies can be used in the designing of automated control systems of the constructive and mode parameters of bulk materials separators.
Keywords: bulk material, separation, modeling, aerodynamic properties, geometric dimensions, bulk weight.
1. Richard, G. Holdich. (2002). Fundamentals of Particle Technology. Midland Information Technology and Publishing. Shepshed, Leicestershire, U.K. 173 p.
2. Gary W. Delaney, Paul W. Cleary, Marko Hilden, Rob D. Morrison. (2009). Validation of dem predictions of granular flow and separation efficiency for a horizontal laboratory scale wire mesh screen. Seventh International Conference on CFD in the Minerals and Process Industries CSIRO. Melbourne, Australia. 9-11 December. P 1-6.
3. Hans, J. Herrmann. (1993). Molecular dynamics simulations of granular materials. International Journal of Modern Physics C. Vol. 4. No. 2. P. 309–316.
4. Ferrara, G., Preti, U., Schena, G. D. (1987). Computer-aided Use of a Screening Process Model. APCOM 87. Proceeding of the Twentieth International Symposium on the Application of Computers and Mathematics in the Mineral Industries. Volume 2: Metallurgy. Johannesburg, SAIMM. P. 153–166.
5. Pertti Broas. (2001). Advantages and problems of CAVE-visualisation for design purposes. Trans. VTT Symposium Virtual prototyping. Espoo, Finland, February 1 st. P. 73–81.
6. Bai C. (1996). Modelling of spray impingement processes. Ph.D Thesis. University of London.
7. Dominik Kubicki, Simon Lo. (2012). Slurry transport in a pipeline – Comparison of CFD and DEM models. Ninth International Conference on CFD in the Minerals and Process Industries. CSIRO, Melbourne, Australia (10-12 December 2012). P. 1-6.
8. Sang Won Han, Won Joo Lee, Sang Jun Lee. (2012). Study on the Particle Removal Efficiency of Multi Inner Stage Cyclone by CFD Simulation. World Academy of Science, Engineering and Technology. Vol. 6. P. 411–415.
9. Satish G., Ashok Kumar K., Vara Prasad V., Pasha Sk. M. (2013). Comparison of flow analysis of a sudden and gradual change of pipe diameter using fluent software. IJRET: International Journal of Research in Engineering and Technology. Vol. 2. P. 41–45.
10. Bai, C., Gosman, A. D. (1995). Development of methodology for spray impingement simulation. SAE Technical Paper Series. 21 p.
11. Khalid M. Saqr, Hossam S. Aly, Mazlan A. Wahid, Mohsin M. Sies. (2009). Numerical Simulation of Confined Vortex Flow Using a Modified k-e Turbulence Model. CFD Letters. Vol. 1(2). P. 87-94.
12. Wallin, S. (2000). Engineering turbulence modeling for CFD with a focus on explicit algebraic Reynoldce stress models. Doctoral thesis. Norsteds truckeri, Stockholm, Sweden. 124 p.