Using vibration to attenuate the adhesive friction behavior between screw conveyor blades and wet coal particles

Abstract

Screw conveyors are widely used in the transportation of materials in the mining field. The characteristics of material the water content and material shape differences make it different from other powdery and other uniform particle adhesion and friction phenomena, which affects the conveying performance. In order to improve the capability of conveying particles, this paper adds the consideration of vibration factors on the basis of the existing particle lifting test, aiming to study the adhesion and friction mechanism of multi-shaped wet particles under the influence of vibration, and to determine the work parameter that can help improve the conveying performance. The trajectory of microscopic particles under radial and axial vibration conditions, the wear amount of particles on blades and the statistics of particle adhesion and friction intensity are analyzed by discrete element method. The test results show that the adhesion strength of wet coal particles will increase with the increase of water content, and vibration can reduce its adhesion and friction characteristics, and the impact of amplitude and frequency changes is different. The improvement of the amplitude and frequency of the axial vibration of the screw blade can improve the wet coal conveying rate and reduce the wear of the blade. In radial vibration, the transportation rate of wet coal first increases and then decreases with the increase of the amplitude, but the wear amount gradually increases and causes adhesion phenomenon. The transportation rate increases with the increase of frequency, but the wear amount first decreases after increasing. The direction of the radial vibration has an effect on the wear and has little effect on the transportation rate. These results can provide guidance for reducing the adhesion of wet particles and improving the conveying rate in screw conveying.