【作者】 吕有厂；

【导师】 林柏泉；

【作者基本信息】 中国矿业大学 ， 安全技术及工程， 2012， 博士

【摘要】 煤矿井下瓦斯抽采钻孔风力排粉施工过程中产生大量的粉尘，这种扬尘不仅对施工人员造成矽肺疾患，而且是煤尘爆炸和燃烧的事故隐患，对煤矿形成重大威胁。因此必须研究一种高效的除尘设备对粉尘进行治理。本文分析了井下钻孔施工过程中钻孔孔口及巷道煤尘扩散、流动、沉降的规律，研究了钻孔孔口集尘、捕尘、消尘方法，综合运用多相流流动理论、水射流负压理论、引射理论、射流泵理论，确定了钻孔孔口除尘装置设计方案，主要工作和取得的研究成果如下：（1）研究了井下钻孔风力排粉钻孔粉尘运动及浓度分布规律：粉尘从尘源处产生后，大于1.5～2mm的颗粒迅速沉降，落向底板；其余大部分游离粉尘迅速从孔口向外扩散充满巷道并沿风流方向运动，由于风流是湍流运动，粉尘运动不规则的呈雾状充满巷道，易对人体健康和生产安全造成危害。（2）提出了以中压为力源的水射流负压除尘技术：首先以集尘装置将钻孔施工时产生的粉尘控制在相对密封的空间内，用压力泵将水压达到16MPa，并安装在一定直径管道内的喷头高速喷出，这样在喷头的后方形成负压区，通过小阻力的管路与集尘器连接并将钻进过程中产生的粉尘抽入管道内，抽放管道内的粉尘高速与喷头喷出的水雾流混合，并在水雾流中悬浮，高速水雾流以高粘度的特性与粉尘高速摩擦并完全湿润，在一定速度下不产生沉降而被排出管道外，达到除尘的效果。（3）设计了水射流负压除尘装置：装置主要由集尘装置、支撑装置、除尘装置、动力装置和连接管线集成，通过ANSYS CFX数值模拟软件对喷嘴个数、喷嘴安装角度、混合管长度和侧向吸尘管位置进行参数优化，实现高效除尘；用FLUENT流体模拟软件模拟分析喷孔情况下除尘装置内压力分布，结果表明在喷孔情况下装置仍可使用。（4）进行了40多组数值模拟、60多次地面模拟实验和12个矿30多个测点160多次井下现场施工测试记录：测定钻孔除尘系统的性能参数和除尘效率，现场使用结果表明，打钻过程中巷道粉尘降低90%以上，浓度由原来的300～400mg/m~3降低到3.5mg/m~3。更多还原

【Abstract】 Heavy dust is produced while use wind power to exhaust dust in coal minedrilling. The dust brings not only silicosis disorders to the workers, but also exists as amajor threat and a potential trigger of accidents, fire and explosion included. So it isessential to develop an efficient dust removal equipment to control the dust. In thisessay, the diffusion of dust caused by drilling under the ground was discussed and therules of the flow and sedimentation of the dust produced in the drilling hole and theroadway were studied. Then based on the principles of multiphase flow, water jetvacuum theory, ejector theory and jet pump theory, a dust removal device in drillingholes was designed. The main results are shown as follows:1. The rules of distribution and movement of the dust exhausted by wind underthe ground were studied. The dust leaves from the coal and the particles whose sizebeyond2mm rapidly down on the plate, while other runs out of the drilling hole andspreads outward, which fills the roadway fully and moves with the airflow. Because ofthe turbulent motion of the airflow, the dust moves irregularly, making the roadwaymisty, which is harmful to individuals and serves as a threat to production.2. The mechanism of a pressurized water jet vacuum dust removal process wasgiven. To begin with, the dust is controlled in a relatively sealed space. When waterpressure reaches16MPa, it is erupted at speeds from a nozzle in the pipe with acertain diameter, so that a negative pressure zone is formed at the rear of the nozzle.This negative pressure was linked to a collector through little resistant pipes. Dust inthe drainage pipe mixes with spray erupted from the nozzle, and suspended in thespray stream. This high-speed and high-viscosity stream rubs against dust so rapidlyto wet the dust, then the dust will not come into sedimentation at certain speed, and itis discharged from the pipe to reach the goal of dust removal.3. A water jet vacuum dust removal device was designed, which is mainlyconsisted of a dust collection device, a supporting device, a dust removal device, apower device and several connecting lines. To get a efficient goal of dust removal, wehave carried on a series of parameter optimization experiment about the number ofnozzles, angle of nozzles, mixing tube length and position of lateral direction through the numerical simulation software ANSYS CFX. Also the internal pressuredistribution is simulated in the case of nozzles is installed by fluid simulation softwareFLUENT. The result shows the device can still be used in the case of nozzle.4. In order to test the performance parameters and collection efficiency ofdrilling dust removal system, more than20groups of numerical simulation,10experiments of ground simulation and test records of12mines and more than30measurement points, over160site operation under the ground were done. The resultsshow that the content of dust in the tunnel decreases by more than90%, concentrationtransforms from300~400mg/m~3to3.5mg/m~3.更多还原