破碎硐室粉尘质量浓度分布的数值模拟及实验

Numerical simulation and experimental research on dust concentration distribution in crushing chamber

摘要:

为了改善破碎硐室粉尘质量浓度超标的现状,获取合理的通风除尘参数,根据相似原理,结合气固两相流的运动方程,导出了模拟破碎硐室粉尘运动的相似准则数,建立了破碎硐室相似模型,运用Fluent软件对破碎硐室相似模型粉尘质量浓度分布进行数值模拟,并与相似实验数据对比分析,模拟结果与实验数据基本吻合．研究结果表明：捕捉壁面条件下粉尘质量浓度较之反弹壁面要低；入口风速为0.2~0.5 m/s时,粉尘质量浓度随风速的增大逐步降低．安装抽风除尘系统后,粉尘质量浓度基本保持在2 mg/m³以内,平均除尘率高达90%以上．

Abstract:

To improve the situation of dust concentration exceeds in crushing chamber and obtain rational parameters for the design of dust removal by ventilation, due to the similarity theory and the motion equations of gas-solid two-phase flow, the similarity index was educed and a similarity model device was designed for the specific situation in the crushing chamber. Furthermore, the dust concentration distribution of similarity model in crushing chamber was simulated by using software named Fluent. After the comparison with similar experimental data analysis, the result showed that the simulation result was consistent with the experimental data. Therefore, the results indicated that dust concentration in chamber under trap wall condition is lower than it under the reflect condition. When the wind velocity at entrance was in the range of 0.2 m/s to 0.5 m/s, dust concentration gradually reduced with the increasement of wind velocity. Finally, after the installation of downdraught dedusting system, the dust concentration was below 2 mg/m³, and the average removal rate reached 90%.