负压降尘技术及其应用

本文提出的负压降尘技术，是利用高压水通过降尘装置内的引射装置产生高速水雾射流，从而在降尘装置的吸气部分产生负压，使含尘气流被不断地吸入降尘装置，从而得到洗涤和净化，达到降尘的目的．运用均匀设计方法进行了详细的实验室实验，得出了负压降尘技术的优化参数．根据实验结果，设计了采煤机负压降尘装置，在工业性试验中取得了较好的降尘效果.     

综放面多尘源粉尘分布规律数值模拟及实测

为解决综放工作面粉尘浓度高的问题,掌握各作业工序粉尘浓度空间分布规律,有效指导粉尘控制工作,依据气固两相流理论,运用Fluent软件对综放工作面割煤、移架、放顶煤、转载各工序单独及同时作业时的粉尘分布规律进行数值模拟,并与现场实测数据进行对比分析.结果表明:割煤作业粉尘沿采煤机机道扩散的同时向人行道空间扩散,需在滚筒尘源处控尘,并在采煤机外侧采取水幕帘除尘措施;移架作业时人行道粉尘浓度高于机道粉尘浓度,需在机道空间和人行道空间均设置架间喷雾;放煤作业粉尘沿人行道空间分布较大,需在放煤口采取隔尘措施;转载点局部风速大,粉尘影响范围较广,应采取密封等措施.还应在放煤和割煤作业之间增加全断面喷雾降尘装置.     

A new design of foaming agent mixing device for a pneumatic foaming system used for mine dust suppression

To overcome the drawbacks of the conventional foam technology used for dust suppression,including large pressure loss,high water pressure and low driving pressure,a new pneumatic foaming system is introduced.Then an original design of foaming agent mixing device is proposed,and its performance is investigated and evaluated under different pressure compensations.Experimental results show that the maximum absorption amount increases by 2.9-6.7 times at a pressure compensation of 0.04-0.2 MPa compared with no pressure compensation.The pressure loss and pressure fluctuation both reduce significantly with increasing pressure compensation.The critical outlet pressure increases by30.4-240%.Field application indicates that the proposed mixing device ensures the reliable addition of foaming agent used for foam dust suppression.The effect of foam on dust suppression is remarkable,and the economic cost of foam is low.Therefore,there is reason to believe that the new mixing device will greatly promote foam technology to be widely used for suppressing dust in underground coal mines.     

Controlling the coal dust at transshipment point: A study of the foam-sol foaming device

In order to effectively control the dust at the transshipment point with foam-sol, this paper attempted to study the characteristics of dust diffusion at transshipment point and the foam-sol foaming device with diffusion outlet was also designed in this paper. To study the diffusion rules of coal dust, fluent discrete phase model was utilized in the numerical simulation, as the coal dust was thrown down at a horizontal velocity of 2.5 m/s. A foam-sol foaming device was designed, through which foaming agent could be automatically sucked into the Venturi by the negative pressure. The automatic controller was also equipped, which could transform the energy of the compressed air into the constant pressure difference so that the gelling agent could be qualitatively added into the gel container. The diffusion outlet that could spray out foam-sol in a continuous, conical and 3D manner was also designed. Moreover, this paper also carried out the contrast experiments on dust removal efficiency among water, aqueous foam and foam-sol. The results clearly show that the symmetrical whirlpools appeared below the inlet where the largest whirlpool diameter was 0.52 m, and the horizontal distance from swirl range to the inlet was approximately 0.69 m. By using the self-designed foaming device, the foaming was multiplied by 30 times and the volume ratio with water and foaming agent reached 95%:5%. In this context, the gas pressure was controlled at 0.3 MPa, with gas flow at 15 m³/h and water flow at 0.5 m³/h, with water pressure controlled between 0.34 and 0.36 MPa. The foam-sol has the highest dust removal efficiency than other agents.     

在线加湿压力和加湿流量对PM_(10)排放的影响

利用实验室粉体物料自由下落在线加湿模拟试验装置,研究气水两相喷嘴中的加湿压力和加湿流量对不同粉体物料中PM10排放的影响。通过实验,获得的最佳加湿压力为0.30MPa,最佳加湿流量为2.4 L/h。利用最佳加湿压力和最佳加湿流量可以优化在线加湿条件,达到最佳的降尘效果和节约降尘成本。     

煤层干式钻孔粉尘质量浓度分布规律的数值模拟

干式钻孔过程中,风力排渣系统将钻屑沿钻孔环状狭缝高速排出,会产生高浓度粉尘.为有效地控制煤层干式钻孔粉尘污染,探寻影响粉尘分布的主要因素,确定出粉尘质量浓度较低的钻孔工艺参数配置,运用SolidWorks联合DesignModeler建模、Mesh划分网格、Fluent解算、CFD-Post后处理等手段,对不同边界条件下煤层干式钻孔粉尘质量浓度分布进行数值模拟,并与现场实测数据对比分析,两者基本吻合.研究结果表明:压风自环状狭缝喷出后速度急剧衰减,整体呈锥体分布,大颗粒钻屑喷出孔口后就地沉降,细小颗粒悬浮在空气中并随风流继续扩散;钻场内粉尘质量浓度沿程先急剧上升至一个最大值,后快速下降,再逐步缓慢降低;水平方向上,机道中央粉尘质量浓度最高、巷道中央次之、人行道中央最低;竖直方向上,粉尘质量浓度呈现出中间高、上下两侧低的分布规律;钻场风速、钻杆转速、供气压力、钻杆型式及钻孔类型是影响粉尘分布的5个主要因素;当钻场风速为0.5 m/s、钻杆转速为2 r/s、供气压力为0.8 MPa时,采用外平钻杆钻进斜平行预抽钻孔,可取得良好的减尘效果.研究成果可有效地指导现场钻孔作业和防尘装置研发.     

综采工作面割煤时煤尘污染状况的现场实测研究

在对平沟煤矿综采工作面采煤机割煤时煤尘浓度和分散度现场实测和分析的基础上,得出了综采工作面采煤机割煤时煤尘的污染特征.在一定风速条件下采煤机割煤时,距底板和煤壁较近处煤尘的总粉尘浓度沿程分布曲线出现2个极大值,然后随着煤尘运移距离的增加,煤尘的总粉尘浓度沿程分布曲线趋向于1个稳定值;距顶板和液压支架较近处煤尘的总粉尘浓度沿程分布曲线仅出现1个极大值,然后随着煤尘运移距离的增加,煤尘的总粉尘浓度沿程分布曲线也趋于1个稳定值.     

掘进工作面高压水细射流除尘规律研究

通过井下高压水细射流辅助破岩系统的掘进机工作面在掘进期间变化压力水释放的压力进行除尘的一系列试验，并综合已有的井下掘进工作面高压水细射流除尘的资料，总结出掘进期间压力水释放压力与粉尘产尘率之间的关系，并由此推出高压水细射流除尘的最佳水压范围。     

Numerical simulation of dust distribution at a fully mechanized face under the isolation effect of an air curtain

At a fully mechanized working face of a coal mine as prototype, we investigated, by simulation, the flow field and dust distribution during the process of its isolation by a curtain of air, using the CFD software,Fluent. The results show that the air curtain installed on the shearer can effectively prevent the dust (especially the respirable dust) from diffusing into the work area of the operator, reducing the dust concentration on the side of the operator and greatly improving his working environment The field application of the air curtain shows that the dust-isolation effect of an air curtain is quite noticeable. The isolation efficiency for respiratory dust is over 70% and, as well, it has good dust-isolation effect for nonrespiratory dust. The air curtain is a useful way to resolve the problem of dust-isolation at a fully mechanized working face. It has a practical background elsewhere with more extensive applications.     

Surface characteristics and wetting mechanism of respirable coal dust

In this study,FTIR and XPS spectroscopy,specific surface area and pore size analyses,wetting and other experimental means have been applied to investigate respirable coal dust surface properties and wetting mechanism.The research shows that coal dust surface structures,chemical and element compositions are changed in the refining process of coal dust.Compared with large particle coal dust,respirable coal dust is a weak hydrophilic and strong hydrophobic substance.The reason:the smaller the particle size of coal dust,the more unsaturated its surface.The absorption of air is strong and it is easy to form an air film on coal dust surfaces.Coal dust contact with water is actually a compound contact of liquid in contact with a solid and gas in contact with a solid.The smaller the particle size,the larger the pore volume and the higher the degree of surface roughness,the larger the area of gas in contact with a solid and the worse the coal dust wettability.Another reason is that the changes in the composition of atoms on the dust surface and structures affect coal dust wettability.The results of this study establish a theoretical basis for the invention of effective reduced-dust technology.     

高温滤料对去除有害气体方面的研究

钢铁、水泥、煤电等高耗能企业生产中所产生的高温烟尘不仅导致空气中含尘量增大,同时还伴随有大量的氮氧化物、硫化物等有害气体的排放,导致雾霾产生,大气污染严重。烟尘的治理集中于除尘及脱硫脱硝以除去有害气体。分析了当前烟尘治理的研究现状,对袋式除尘器及其滤袋的研究成果及现有脱硝技术予以归纳总结,为今后研究思路和方向提供借鉴。     

煤粉—惰性介质混合体系爆炸特性实验研究

为深入认识煤粉—惰性介质混合体系爆炸行为,在Siwek 20 L球形爆炸测试系统内研究了煤粉—惰性介质混合体系的爆炸威力(最大爆炸压力、最大升压速率、燃烧持续时间)、敏感度(爆炸上、下限)和惰性介质的抑爆效力,并重点考察了点火能量、煤粉热值、惰性介质组分、煤粉浓度、煤/惰性介质混合比等因素的影响。结果表明,添加惰性介质能显著降低煤粉爆炸威力,其抑爆效力随点火能量增加而下降,并由此建议采用5～10 kJ点火能量考察惰化效应;煤粉热值增加可显著提高混合体系的爆炸威力;就惰化效应而言,湿分的抑爆效力优于磷酸二氢铵和碳酸钙,而磷酸二氢铵的抑爆效力又优于碳酸钙,其中煤粉完全惰化所需惰化剂量与煤尘浓度密切相关,在200～400 g/m3处有最大值,为"最危险浓度";增加惰性介质添加量可降低爆炸上限,提高爆炸下限,有效压缩煤粉尘可爆浓度范围。研究结果对深入理解粉尘爆炸规律、优化惰化标准,完善测试方法有参考价值。     

烟尘浓度检测装置的设计

为了更有效地测量环境中的烟尘浓度,监测和改善空气质量,利用光电技术将尘粒浓度转换为成比例的电信号,以16位SPCE061A凌阳单片机为控制核心,设计实现了对烟雾浓度的检测,并给出了单元模块设计电路和配套的软件流程图。该装置可检测锅炉、工业、汽车尾气等污染源的烟尘浓度,并能进行连续监测,实现超值报警。实验表明,该装置烟尘浓度检测精度为0.1%,稳定性高。     

Floor dust erosion during early stages of coal dust explosion development

An ignition of methane and air can generate enough air flow to raise mixtures of combustible coal and rock dust. The expanding high temperature combustion products ignite the suspended dust mixture and will continue to propagate following the available combustible fuel supply. If the concentration of the dispersed rock dust is sufficient, the flame will stop propagating. Large-scale explosion tests were conducted within the National Institute for Occupational Safety and Health (NIOSH) Lake Lynn Experimental Mine (LLEM) to measure the dynamic pressure history and the post-explosion dust scour depth. The aim of this effort is to provide quantitative data on depth of dust removal during the early stages of explosion development and its relationship to the depth of floor dust collected for assessing the incombustible content most likely to participate in the combustion process. This experimental work on dust removal on is not only important for coal mine safety but also for industrial dust explosions.     

Migration law of respirable dust on a super-long fully mechanized double-shearer working face

In order to understand the migration law of respirable dust and gain reasonable design parameters for dust control on a super-long double-shearer fully mechanized working face, this paper describes research carried out using a numerical simulation package(Fluent) based on gas-solid coupling dispersed multiphase flow model and field measurement to research different technology modes, dust distribution law at different intervals where shearers work in opposite directions on the lower 9303 face, No. 2 Jining Mine,Yankuang Coal Mining Co. Results show that the concentration of dust 3–6 m away from the shearers working in the same directions was large, while the impact area of respirable dust near the shearer increased significantly to 5–6 m with the distance between two shearers working in opposite directions.The concentration of dust on a double-shearer face was considerably higher than that of a face with one shear under the combined effect of wind speed on the face and disturbed wind around the shearer, while the dust concentration near the shearer on the return side was considerably higher than that on the inlet side. The concentration of dust on a double-shearer face along the airflow declined slowly so that dust was hard to control. Simulation results confirmed the results of field measurement, which could provide reference for dust prevention design.     

煤流加湿抑制粉尘散发的实验研究

本文提出了用煤流加湿机加湿煤流抑制粉尘散发的方案,并介绍了其工业实验。对煤流进行加湿能显著地降低煤流散发的粉尘量,是用水治理煤粉尘污染方法的一个发展。该方案还可用于其它物料加湿以抑制粉尘散发。     

FGD系统烟气流速测量仪表选型

FGD的全称为湿法烟气脱硫,是火力发电厂、化工厂厂用高压蒸汽锅炉等应用最广泛的脱硫装置.烟气流速是环保监测和数据上传环保局采集终端的一个重要参数,涉及与环保部门的排放总量的结算.因为湿法烟气脱硫系统入口烟气温度和流速较高,且含有大量的燃煤灰尘,因此对风量测量装置提出了较高的要求,甚至需要特殊的风量测量装置.而湿法烟气脱硫系统出口烟气中温度虽然较低(一般在48℃～52℃之间),但是因其含有大量的水蒸气和石膏浆液,热导式风量测量装置、文丘里风量测量装置、机翼式风量测量装置、节流差压风量测量装置、超声波风量测量装置等都无法正常使用,因此湿法烟气脱硫系统出口、入口烟气流速测量装置的选型工作是十分重要的工作,错误的选型会导致后续工作极度被动,因此有必要介绍一下相关经验.     

Application of foam technology for dust control in underground coal mine

In order to effectively control the dust in the underground coal mine, this study proposes and develops a new technology for dust control by foam, and briefly demonstrates the advantage of the foam technology for dust control, such as the good isolation performance, large contact area, high wetting ability, strong adhesion and so on. Besides, the details of the technology are introduced, including the foam agent, foam generator, and foam production process. Then the paper studies the relationship between the foaming agent concentration and liquid surface tension, and explains the principle of the foam generator. The technology is applied in heading face. The application results show that the foam has a remarkable effect on dust control in underground coal mines.     

A new adding method of foaming agent used for foam dust suppression in underground coal mines

To realize a stable addition of foaming agent used for foam technology, a new adding method using the jet cavitation was introduced, and its performance was investigated experimentally under different operating conditions. Experimental results show that the bubble region in the jet device has a constant vapor pressure, which creates a good condition for liquid absorption, while it shrinks with increasing outlet pressure. The liquid absorption amount keeps unchanged when the outlet pressure is lower than a critical value. The critical outlet pressure increases by 40% with decreasing cavitation absorption amount, which is especially suitable for mini-flow quantitative addition of foaming agent used for foam dust suppression. Its effectiveness on suppressing mine dust was evaluated in a heading face of underground coal mines. Field application indicates that the reliable and simple foaming system adopting the new adding method makes a marked dust suppression effect. The working environment of heading face is significantly improved, ensuring the safe tunneling and personal security.     

原粮除尘装置的研究设计

研究设计了一种新型的原粮加工除尘装置。该装置既可提升粮食,又可分离粉尘和轻杂,有效地控制了粉尘外扬,耗电少,磨损小,除灰、除杂效率高。操作安全、方便。