煤矿胶带转载点多径向旋流卷吸除尘技术

Multi-radial cyclone suction dust removal technology at coal mine belt transfer points

  • 摘要: 胶带转载点粉尘危害与治理是实现煤矿高效、安全、清洁生产的重要问题之一。为解决转载点粉尘污染问题,降低转载点粉尘危害,根据旋流卷吸理论,提出胶带转载点多径向旋流卷吸除尘技术。该技术是在竖直设立的落料管侧壁上安设一定数量和射流角度的进风口,抽风口设置在落料管正上方。工作原理是落料管侧壁射入的风流遇到侧壁改变方向,进风口射流相互作用下,在落料管内形成向上流动的旋流,抽风口负压牵引旋流携带粉尘流入除尘器,实现粉尘净化。通过建立高度仿真的3D实体模型和搭建胶带转载点多径向旋流卷吸除尘技术试验平台,采用数值模拟和试验测试相结合对转载点内风流分布、粉尘运移分布进行研究。数值模拟和试验测试中在落料管4个侧壁上分别设有8个倾斜向上且与水平面夹角为10°的进风口,导料槽上设有4个进风口,进风口朝向与下级胶带上粒子释放位置的圆相切。根据旋流卷吸理论得出:落料管上进风风速越大,落料管边界与中心压力差越大,对粉尘的聚集效果越好。模拟结果得出:多径向旋流卷吸除尘技术最佳进风速度为8 m/s,此时可收集下落过程中粒径小于50 μm的粉尘和煤料与下级胶带撞击产生的粒径小于30 μm的粉尘。对比试验中下落前后煤料分散度得出:除尘技术应用后下级胶带上煤料中粒径小于50 μm的颗粒占比减小47.96%,粒径小于5 μm的颗粒减小44.62%,降低煤料中有害颗粒的占比;通过测定导料槽两端及入料口处粉尘质量浓度,试验确定多径向旋流卷吸除尘技术最佳进风速度为8 m/s,此时,导料槽左右两端及入口处粉尘质量浓度最低,除尘效率分别为97.71%和99.92%,转载点整体的除尘效率可达95%以上。证明转载点多径向旋流卷吸除尘技术可以解决转载点粉尘污染难题,改善转载点处工作环境。

     

    Abstract: The dust hazard and management at the belt transfer point is one of the most important issues in achieving efficient, safe and clean production in coal mines. To address the problem of dust pollution at the transfer point and to reduce the dust hazard at the transfer point, a multi-radial cyclone suction dust removal technology is proposed for the belt transfer point based on the cyclone suction theory. The technology is based on a certain number of inlets and jet angles on the side wall of the vertical drop pipe, with the suction outlet set above the drop pipe. The principle of operation is that the incoming air-flow from the side wall of the drop pipe changes direction when it meets the side wall and the inlet jets interact with each other to form an upward flowing cyclone in the drop pipe. A simulated 3D solid model and a test platform for multi-radial cyclone suction dust removal at the belt transfer point are built. A combination of numerical simulations and experimental tests is used to study the distribution of air-flow and dust transport in the transfer point. In the numerical simulation and experimental tests, eight air inlets are provided on each of the four-side walls of the drop pipe at an angle of 10° to the horizontal, and four-air inlets are provided on the guide chute, with the air inlets oriented tangential to the circle of the particle release position on the lower belt. According to the cyclonic suction theory, the greater the inlet air velocity on the drop pipe, the greater the pressure difference between the boundary of the drop pipe and the center, and the better the effect on dust collection. The simulation results show that the best inlet air speed for the multi-radial cyclone suction technology is 8 m/s, where the dust of less than 50 μm and the dust of less than 30 μm from the impact of the coal with the lower belt can be collected during the drop. Comparing the dispersion of the coal before and after falling in the test, it is concluded that the proportion of particles smaller than 50 μm in the coal on the lower belt is reduced by 47.96%, and the proportion of particles smaller than 5 μm is reduced by 44.62% after the application of the dust removal technology. It reduces the proportion of harmful particles in the coal. By measuring the dust concentration at the ends of the guide chute and at the inlet, the test determines that the best inlet air speed for the multi-radial cyclone suction dust removal technology is 8 m/s. At this time, the dust concentrations at the left and right ends of the guide chute and at the inlet are the lowest, and the dust removal efficiency is 97.71% and 99.92% respectively, and the overall dust removal efficiency at the transfer point can reach more than 95%. The study proves that the multi-radial cyclone suction dust removal technology at the transfer point can solve the problem of dust pollution , improve the working environment .

     

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