Complex Effects of Drum Hub Forms and Structural Parameters on Coal Loading Performance

Kuidong Gao,Kao Jiang,Qingliang Zeng,Liqing Sun,Xiaodi Zhang

doi:10.1155/2020/7036087

Abstract

The extremely poor loading performance of a thin coal shearer drum affects the mining efficiency in thin seam mining seriously on account of the restriction by the complicated mining environment and seam thickness. The coal loading performance of the drum is influenced by several complex factors, such as motion parameters and structural parameters, including the structure and form of the hub. The form of the drum hub is cylindrical in general, and in order to study the influence of the hub form on the coal loading rate of the drum, seven drums with different hub forms and structures were designed. The influence of the complexity of hub structures on the coal loading performance was studied by discrete element method (DEM) simulation in this paper. The change curves with the research object of different drums, such as coal loading rate, velocity field distribution, and contact force between fallen coal particles, were obtained. The results showed that the conical hub drum can improve the coal loading performance than the cylindrical hub drum, and the curve-shaped hub drum had a more obvious promotion on the coal loading performance. The coal loading rate increased first and then decreased with the increase of hub cone angle. Compared with the conical hub drum, the curve-shaped hub drum can not only improve the coal loading rate, but also has a larger space containing coal. This study has proposed a drum with a new form hub which could increase the coal loading rate, and the methods and conclusions provide the guidance for drum hub design.

Highlights

Potyondy and Cundall [26] proposed that the discrete element method (DEM) can simulate the bulk properties of the real coal rock after crushing, and the crushed coal rock had the properties of the granular material, so the DEM can be applied to the analysis of the coal loading performance of the drum
In the process of mining thin coal seam, the coal cutting and loading mainly depend on the front drum. erefore, this paper only focused on the coal loading performance with the drum ejection method
DEM was employed in this paper to study the loading performance of the drums above with different rotational speeds. e complex influence mechanism of the drum hub on the coal loading performance was analyzed and studied by some research objects, including the particle velocity, drum space capacity, and contact force between particles

Summary

Simulation Model Establishment

In an ideal coal mining process, the coal cutoff from the coal face could be loaded by the drum onto the middle chute of the conveyor and transported out of the working face. Based on the above problems, the effect of the drum on particle ejection speed and axial velocity has an important impact on the coal loading performance. E equipment of the coal mining working face is mainly composed of a shearer, a hydraulic support, and a chain conveyor, for coal cutting and loading, supporting the roof, and transportation, respectively. It has been proved that the ranging arm of the shearer and the relative position relationship between the chain conveyor and the drum have a significant effect on the coal loading rate [13, 30], so the ranging arm and the chain conveyor model were established in simulation. In order to reveal the coal loading mechanism and the drum-particle interaction mechanism of drums with different hubs, the number and

III IV V VI VII VIII Drum

Analysis of the Simulation Results and Discussion

III IV V VI VII VIII

Findings

Conclusion