Research on Slurry Transportation and Wear in Underground Coal Mines

Abstract

Purposes: As a conveying method that uses fluid energy to transport materials in pipelines, pneumatic conveying offers advantages including simple structure and flexible pipeline layout. However, long-distance pneumatic conveying in coal mine shotcreting systems faces problems such as poor performance of shotcreting machines, severe equipment wear, which seriously endanger the safety of workers and hinder the construction speed of bolt-shotcrete support. Therefore, determining appropriate operating parameters and developing reliable wear prediction models have become important research objectives. Method: Based on the Eulerian–Lagrangian method and the coupled CFD-DEM approach, the influence laws of three parameters, namely particle size (6–10 mm), particle mass flow rate (3–7 t/h), and fluid flow velocity (10–20 m/s), on the wear of the rotor were investigated. Furthermore, a three-factor, three-level orthogonal experiment was designed, with particle size, particle mass flow rate, and fluid flow velocity selected as experimental factors, to determine the significance ranking of each parameter’s effect on wear. Findings: Experimental results show that when the particle size is 8 mm, the particle mass flow rate is 5t/h, and the fluid flow velocity is 15m/s, the rotor exhibit low wear volume and good conveying stability. It is also found that the particle mass flow rate has the most significant effect on the wear of the rotor, while the effects of fluid flow velocity and particle size are relatively minor. Conclusions: This study overcomes the cumbersome operation issues of traditional process experiments. By combining parameter optimization with CFD-DEM coupled simulation, it provides a new method for selecting the optimal parameter combination.