Pneumatic conveying technology is an efficient, energy-saving and environmentally friendly means of solid feed conveying. In the process of pneumatic conveying, wind speed has a decisive influence on conveying characteristics. Here, computational fluid dynamics coupled with a discrete element method simulation and experiment were combined, and the conveying wind speed was used as the experimental variable to study the conveying characteristics of the conveying material in the tube, such as particle distribution state, solid phase mass concentration, coupling force on solid feed, average speed and pressure drop of solid feed in the pipe. The results show that when the conveying wind speed increases from 18 m/s to 20.6 m/s, the solid feed changes from sedimentary flow to suspended flow, the particle accumulation gradually decreases and the conveying efficiency is significantly improved. The particle slug greatly reduces the collision and friction between the internal particles and the pipe and reduces the crushing rate to a certain extent. When the conveying wind speed is about 23.2 m/s, there are almost no trapped particles in the pipeline, which can achieve rapid feed delivery, and conveying efficiency is greatly improved. Therefore, this paper provides a good theoretical basis for improving conveying efficiency and reducing crushing rate in the process of pneumatic conveying.

Intermittent tilting pouring is widely utilized in metal casting due to its operational simplicity and cost-effectiveness. However, this method faces challenges such as difficult manual tuning and inconsistency in achieving constant flow rates. Targeting pouring equipment at a high-purity metal smelting company, this study proposes a closed-surface flux calculation method based on the Gauss divergence theorem to determine molten metal volume at any given instant. A mathematical model for pouring processes involving ladles with non-cylindrical inner surfaces is established. Based on this model, pouring characteristics are analyzed. Through piecewise fitting, angular velocity functions for constant flow rate pouring are derived, which provides theoretical guidance for practical industrial operations.