涂装废气漆雾分离的流场模拟与试验研究

Simulative and experimental study on separation of paint mist from exhaust gas generated by paint spraying

在处理含有大量漆雾、挥发性有机物等有害物质的喷漆废气时,干式过滤法与湿式净化技术相比更经济有效,但容易产生堵塞问题。本文分析了漆雾的特性及干式过滤器堵塞的机理,提出了拦截-过滤耦合工艺和自制了实验装置。首先采用流体动力学的计算方法建立数值模型,优化了折流板拦截装置的结构和运行参数。数值模拟研究的结果表明:在板间距20 mm、折角90°、入口气流速度8 m/s的条件下,折流板拦截装置的压降为220.2 Pa,对直径15μm的漆雾的分离效率为84.7%。在上述优化条件下进行了试验验证,实测折流板拦截装置的压降和漆雾分离效率分别为303.3Pa和78.34%,整个拦截-过滤耦合装置的漆雾分离效率达到96.38%。

For treating the exhaust gas generated from paint spraying which contains a large amount of paint mist,volatile organic compounds,and other hazardous substances,dry filtration is more cost-effective than wet purification,but confronted with the clogging problem.The characteristics of paint mist and the clogging mechanism of dry filter were analyzed.A process combining interception and filtration was developed for separation of paint mist from paint spraying exhaust gas,and a corresponding device was made for experiments.A numerical model was established to optimize the structure and operation parameters of the baffle interceptor by hydrodynamics.The simulation results showed that the separation efficiency was 84.7%for the paint mist with a diameter of 15μm and the pressure drop of the baffle interceptor was 220.2 Pa under the following conditions:plate spacing 20 mm,folding angle 90°,and inlet airflow velocity 8 m/s.The application experiments using the homemade device were conducted under the said conditions,and the results showed that the pressure drop of the baffle interceptor was 303.3 Pa,and the paint mist separation efficiency was 78.34%for the baffle interceptor and 96.38%for the combined interceptor-filter device.