Numerical simulation of the particle flow and sieving behaviour on sieve bend/low head screen combination

This paper presents a numerical study of the particle flow and sieving behaviour of a sieve bend/low head screen combination in coal preparation. The particle flow is simulated by discrete element method while the water flow on the sieve bend is modelled by computational fluid dynamics. The effects of operational conditions are investigated by a series of controlled numerical experiments. The particle flow on the screen is analysed in terms of the velocity field, particle spatial distribution and residence time, while the sieving behaviour is analysed in terms of the overall percentage passing and percentage passing distribution along the screen. For the sieve bend, a large amount of water with slow velocity is preferable for overcoming cohesion between particles and controlling particle velocities, which can improve the percentage passing. For the low head screen, increasing the incline angle and the vibration amplitude in the horizontal direction can increase the throughput while maintaining the percentage passing.

Discrete element method has been used to simulate the screening process on the sieve bend and low head screen combination in coal preparation. The effects of key operational variables, such as the water flow on the static sieve bend and the vibration conditions on the vibrating low head screen, on the flow and sieving behaviour are examined on a particle scale.Figure optionsDownload as PowerPoint slideHighlights
► DEM is used to simulate particle flow on a sieve bend/low head screen combination.
► The effects of key operational variables on sieving performance are studied.
► Methods for improving sieving performance are discussed.