Model parameter setting.

Based on the engineering background of the Huaibei Coal Preparation Plant in Anhui Province, China, this study aims to effectively mitigate dust pollution during the blanking process at coal transfer points. Given the limitations of conventional dust control measures, a numerical simulation was conducted using the Euler model and discrete element method (DEM) for simulating particulate matter. The simulation incorporated the two-way coupling effect between gas-solid two-phase flow and the collision-adhesion dynamics among particles. We examined the migration behavior of dust within an unpowered dust removal system under various technical parameters. Results indicate that installing a return pipe significantly reduces dust overflow caused by impact airflow during blanking. Specifically, when the return pipe diameter is 500 mm, and the horizontal distance between the drainage port of the return pipe and the bottom of the blanking pipe is 2000 mm, the dust removal efficiency reaches its optimal level. Field tests confirmed that after implementing the improved dust removal system, the ambient air dust concentration decreased to less than 2 mg/m³, representing a reduction of approximately 92.02% compared to pre-transformation levels. This approach overcomes the limitations of traditional dust prevention technologies, inhibits dust generation at its source within the coal conveying system, effectively reduces working space dust concentrations, and ensures occupational health and safety for workers.

本研究以中国安徽省淮北选煤厂的工程背景为依托，旨在有效缓解煤炭转运点落料工序中的粉尘污染问题。鉴于传统粉尘防控措施存在局限性，本研究采用欧拉模型与离散单元法（Discrete Element Method，DEM）开展颗粒物数值模拟研究，模拟过程纳入气固两相流的双向耦合效应以及颗粒间的碰撞-黏附动力学行为。本研究考察了无动力除尘系统内粉尘在不同技术参数下的迁移特性。结果表明，加装返料管可显著降低落料过程中冲击气流引发的粉尘外溢问题；具体而言，当返料管管径为500mm，且返料管排出口与落料管底部的水平间距为2000mm时，除尘效率达到最优水平。现场测试证实，改进后的除尘系统投用后，环境空气粉尘浓度降至2mg/m³以下，较改造前降低约92.02%。该方案克服了传统防尘技术的局限，从源头抑制了煤炭输送系统内的粉尘产生，有效降低了作业空间的粉尘浓度，保障了作业人员的职业健康与安全。