破碎硐室物料尘化机理及时空污染效应和控制方法研究

To effectively solve the dust pollution in crushing chamber,improve the conventional spraying dust-settling technology of high water consumption and its poor dust-settling effect,this project aims to reveal the nonlinear variation mechanism of induced airflow in crushing chamber and the mechanism of material dusting by exploring the relationships between the crusher induced air,dust production and the various factors.Firstly,building the similar experimental device of dust space-time pollution in crushing chamber is to explore interaction mechanism between factors that influence dust space-time distribution and its quantitative relation. The three-dimensional mathematical model of dust space-time pollution in crushing chamber is based on force analysis,then the tensor matrix factorization method and gradient descent method are used to correct the theoretical model gradually by analyzing,decomposing,filling and comparing the actual measurement and theoretical data.The visual computer simulation software made for dynamic simulation of dust movement,dispersal and settlement rules can visually reveal the dust space-time pollution effects in crushing chamber. A research about a new type of air-water mist nozzle determines the optimum structure parameters and optimal operating point and it has found out the relationship between dust suppression effect and influencing factors.Also,the air-water spray dust suppression device suitable for crushing chamber and its physicochemical properties control system have been developed. By determining the installation program and the industrial test,it can reduce the dust concentration in airflow of the crushing chamber and achieve the purpose of dust control.

为有效地解决破碎硐室粉尘污染严重的问题，改善常规喷雾降尘技术耗水量大、降尘效果差的现状，本项目通过探寻破碎机诱导空气量、产尘量与各影响因素间的相互关系，揭示破碎硐室诱导气流非线性变化规律及物料尘化机理；构建破碎硐室粉尘时空污染的相似实验装置，探明影响粉尘时空分布的多因素间相互作用机理及其量化关系；基于受力分析，建立破碎硐室粉尘时空污染的三维数学模型，运用张量矩阵分解法及梯度下降法对实测和理论数据进行分析、分解、填充及对比，逐步修正理论模型。编制可视化的计算机仿真软件，对粉尘运动、扩散及沉降规律进行仿真模拟，动态直观地揭示破碎硐室粉尘时空污染效应；研究一种新型气水雾化喷嘴，确定其最佳结构参数及最佳工况点，得出降尘效果与各影响因素间的相互关系；研制适合于破碎硐室的气水喷雾降尘装置及其雾化性能调控系统，确定现场安装方案并进行工业性试验，使破碎硐室风流中粉尘浓度大幅度降低，达到粉尘控制的目的。

为有效地解决破碎硐室粉尘污染严重的问题，改善常规喷雾降尘技术耗水量大、降尘效果差的现状，本项目以西石门铁矿和安徽开发矿业有限公司李楼铁矿井下破碎硐室作为研究背景，采用现场调研、理论分析、实验研究、仿真模拟、现场应用等研究方法，深入探索破碎硐室诱导气流非线性变化规律、粉尘时空分布特征和气水喷雾降尘技术，并取得了一系列研究成果。研究成果表明：破碎硐室内粉尘主要来源于板式给矿机给矿及颚式破碎机破碎过程，硐室空间全尘浓度及呼尘浓度分布规律基本保持一致，均为在板式给矿机及颚式破碎机附近区域内达到最大值，并以该区域为中心在呼吸带高度平面内径向逐步降低。此外，在风流上游区域内，粉尘浓度较低，风流下游浓度较高。安装抽风除尘系统后，除了破碎机下料口处粉尘浓度达到10mg/m3以外，其余区域粉尘浓度基本保持在2mg/m3以内，平均除尘率高达90%以上。水压一定的条件下，气压分布为0.5~0.7MPa时，气水喷嘴雾化效果较好。扇形、锥形气水喷嘴气液比分别为20和28时，雾化效果最好。当喷嘴孔径为2mm时，雾滴粒径主要分布在20~30μm，喷嘴适用范围更广。破碎硐室现场安装气水喷雾降尘装置后，粉尘浓度大幅度降低，全尘平均降尘效率达94.6%，呼尘平均降尘效率达85.3%。整体来看，使用气水喷雾降尘后，破碎硐室空间内全尘浓度及呼尘浓度均下降至4mg/m3以内，达到了国家相关卫生标准。本项目研制出的新型气水喷雾降尘技术可以有效地改善破碎硐室的作业环境，保障工人的身体健康，对于促进金属矿山安全高效开采具有十分重要的现实意义。此外，本项目的实施为解决金属矿山井下粉尘问题提供了新的思路和方法，研制出的新型、高效、实用的气水喷雾降尘装置在行业内具有良好的推广应用价值，由此可带来巨大的社会和经济效益。