论煤矿巷道掘进防尘措施

在煤矿生产各作业环节中，都会产生大量的煤尘和岩尘，统称为粉尘。通过对煤矿巷道掘进产生粉尘的各环节进行分析总结和现场监测，及时完善防尘控制技术措施，有效地解决了掘进工作面存在的产尘量大、粉尘质量浓度高以及职工作业环境差的难题，进一步促进了矿井安全生产和保障职工生命健康。     

纸盒包装生产线粉尘运移规律研究

目的 研究全自动高速纸盒包装生产线上气流和粉尘的运移规律,从而提供合理的控尘方案.方法 利用Ansys Fluent软件对某制药厂纸盒生产线上气流与粉尘的运动进行仿真模拟,并与现场实测数据进行比较.结果 气流与粉尘的运移轨迹基本一致;在开盒工位,含尘气流互相掺杂,粉尘扩散范围广,落尘严重;在说明书堆叠工位,粉尘受阻碍回流大量散落在承载台表面;在合盒工位,粉尘易团聚落入机构内部;在纸盒料仓工位,部分粉尘因静电吸附在传送带上,未降落粉尘随气流进入开盒区域.结论 文中控尘方案在说明书和纸盒料仓工位设置了吸尘口,以减少粉尘的输出,在开盒工位处设置了吸尘口以阻断粉尘的运移,达到了有效的除尘和控尘效果.     

矿井局部通风机变频控制方法的探讨

文章分析了矿井掘进巷道瓦斯涌出的来源和掘进过程中传统局部通风机由于不能方便的调整风压所带来的局部通风问题,提出了基于瓦斯浓度序列值的矿井局部通风机变频控制的方法。提出了一种利用瓦斯浓度巡检序列差值变化来判断生产工序是否发生变化的方法 ,并针对不同的生产工序分别提出了相应的局部通风机变频控制的方法。针对非掘进工序,提出了利用瓦斯浓度巡检绝对值来控制风机变频等级的方法;针对掘进工序,提出了利用瓦斯巡检浓度值变化来控制风机变频等级的方法,结合现场瓦斯浓度数据进行验证,认为该方法有一定的实用性。     

浅谈煤矿掘进工作面的防尘举措

掘进工作面是煤矿井下最主要的产尘点之一。随着机械化程度的不断提高,巷道不断加大加长,采用单一的降（除）尘技术和措施无法满足生产需要。本文从掘进工作面粉尘的构成人手,确定了粉尘产生的根源,通过对截齿破煤机理、煤层性质、工作结构与参数、掘进机工作方式等方面的研究、分析,确立了掘进防尘的举措。     

掘进机载式临时支护装置在城郊煤矿的应用

基于煤矿掘进巷道临时支护技术的现状,介绍了与掘进机配套的机载式临时支护装置结构和工作原理。分析了机载式临时支护装置与其他临时支护装置的优缺点。机载式临时支护装置增加了支护的强度,实现了综掘临时支护的机械化,缩短了工序时间,为综掘巷道的安全高效掘进和施工安全提供了条件。     

大倾角巷道中激光指向仪的使用

文中介绍了孟津煤矿井下矿井西区底抽巷下山掘进中激光指向仪标示巷道腰线测量方法进行探索。有效地解决了激光指向仪在大倾角巷道中测量安设使用等关联问题。为类似问题提出了解决方案,取得了较好的效果。     

煤巷掘进高效机械化作业线建设与实践

某矿1513运输顺槽针对巷道掘进效率低、机械化程度低、人员劳动强度大和安全系数差的问题,结合现场情况对作业线进行优化升级,通过使用悬臂式掘进机、液压锚杆钻车、液压探水钻车、转载机、可伸缩带式输送机等掘进及运输设备,建立了巷道掘进的机械化作业线,提高了巷道掘进的机械化程度,促进了巷道掘进安全系数和单进水平的有效提升。     

新型除尘技术在中泰矿业选煤厂的应用

本文阐述了选煤厂粉尘的危害及常用灭尘方法,介绍了中泰矿业选煤厂利用新型负压诱导除尘技术对粉尘进行了有效的治理,同时详细说明了负压诱导除尘技术的工作原理,并通过在中泰矿业选煤厂现场布置新型负压诱导除尘喷雾及对其除尘效果的测定,证明新型负压诱导除尘技术达到了预期的灭尘效果,确保了选煤厂员工的身心健康和安全生产。     

掘进工作面综合防尘技术的应用

粉尘是煤矿生产中的主要危害之一,本文介绍了一种新型除尘器及其配套的防尘措施控制掘进工作面粉尘的实践。在生产实践中通过采取该措施,综合机械化掘进工作面的粉尘浓度得到大幅度降低,给操作人员创造了良好的工作环境。     

光散射式数字粉尘测试仪的标定及其应用

环境粉尘浓度的测定一般使用滤膜称重方法测得,该方法费时费力,且不能得到瞬时粉尘浓度的变化。由于光散射式数字式粉尘测试仪性能稳定、灵敏度高,测量方便而广泛的应用于各类测尘应用。文中介绍了光散射式数字粉尘测试仪各项指标的具体标定方法,并结合实际应用,总结了使用过程中应注意的事项。     

Study of high-pressure air curtain and combined dedusting of gas water spray in multilevel ore pass based on CFD-DEM

In order to solve the problem of dust pollution caused by ore unloading in ore pass, this paper, taking Li Lou Mining as a case study, conducted the wind speed variation law in the fluid domain and the impact of the collision between the ore in the unloading process on the fluid to determine the key dust control point based on the CFD-DEM coupling software. By Fluent software, the air curtain dust-proof efficiency under the action of unloading airflow is analyzed, and the relationship between the dust-control wind speed and the impinging airflow is known. And an experimental model of gas water spray is established to analyze the effect of spray dust removal. By analyzing the impact airflow and dust migration caused by ore unloading and the effect of air curtain dust control through numerical simulation, it can be seen that when the ore discharging quantity M_o = 4000 kg, the dust production is mainly concentrated in the fourth middle section. By high-pressure air shield assisting dust removal, dust diffusion can be better controlled when the ratio of impact wind speed of ore pass wellhead (denoted as λ) to high-pressure air curtain wind speed (denoted as ζ) is at least 1:8. When the dust removal effect is optimal, the ratio δ of the water supply amount q_l and the gas supply amount Q_g is determined by the gas water spray dust control experimental platform.     

Fragility analysis of curtain walls based on wind-borne debris considering wind environment

Increasing attention has been attached to the risk assessment and fragility analysis of envelopes of high-rise buildings subjected to the impact of wind-borne debris in hurricanes or typhoons. A probabilistic model of wind-borne debris is proposed in the present paper for risk assessment and fragility analysis of high-building curtain walls based on the numerical solution of three-dimensional flight trajectories of debris and the computational fluid dynamics simulation of local wind environment in a residential area. The influence of sources of randomness in the generation of debris, such as generated location, size, and initial attack angle, as well as local wind environment, on the location of debris impacting on the building curtain wall and the impact damage effect, are considered in the proposed model. The evolution of the probability characteristics of debris is driven by its physical flying behavior in the local wind environment, and the failure probability of each piece of glass of building curtain walls impacted by debris can be determined. Furthermore, a numerical algorithm is given for the fragility analysis under different incoming wind speeds, which can be used to determine the vulnerability and the fragility curve. Finally, two numerical examples for application to residential areas are provided. Results show that the proposed model can provide evaluation and prediction for wind disaster risk and fragility of high-rise buildings in urban areas.     

风震联合作用下高层建筑主体结构和玻璃幕墙的性能研究

为研究风、地震单独及联合作用下,主体结构和玻璃幕墙的性能变化和相互影响,基于高烈度区98 m高框筒结构,依据规范要求增设玻璃幕墙形成总体有限元分析模型,选取3组三向地震动记录,并通过比例为1∶440的缩尺模型风洞试验获得不同重现期的风压时程数据,采用动力弹塑性分析方法,研究风、地震单独与联合作用下主体结构和玻璃幕墙的受力变化。结果表明:主体结构对玻璃幕墙的受力影响大于玻璃幕墙对主体结构的,在风、地震单独及联合作用下,主体结构的层间变形大于玻璃幕墙自身变形。在设防大震和超烈度大震作用下,主体结构的响应和玻璃幕墙的损毁范围随荷载增大而增大,结构变形增长大于结构基底剪力;玻璃幕墙在风荷载作用下未坏,主体结构完好,结构基底剪力、顶部楼层位移和楼层层间位移角呈线性增长;与单独大震作用相比,在1.1倍100年重现期风压和大震联合作用时,结构出现扭转现象,楼层层间位移角之比由1.0增至1.3,主体结构和玻璃幕墙的非线性响应大于风震单独作用的叠加,其中结构顶点位移和最大层间位移角为单独作用时求和值的121%、106%。在大震及风震联合作用下,玻璃幕墙容易发生破坏的位置为平行地震作用主向的侧面。     

Effects of air volume ratio parameters on air curtain dust suppression in a rock tunnel’s fully-mechanized working face

To investigate the effects of the air volume ratio parameters (axial-to-radial flow ratio of the wall-attached air cylinder “δ” and the forced-to-exhaust ratio of the ventilation system “β”) on the air curtain dust suppression in a rock tunnel’s fully-mechanized working face, the eastern belt fully-mechanized working face in Huipodi mining company (Shanxi Mineral Group Co., Ltd., China) was numerically simulated by CFD software in this study. First, a mathematical model for describing the airflow-dust migration in a fully-mechanized working face was established using the Euler-Lagrange method. A full-scale geometrical model of the tunnel was also developed. The effectiveness of the established models and the related parameter settings were then verified by making comparisons between the field measured values and the numerical simulation results. Finally, the airflow migration and dust dispersion rules under different ventilation conditions (δ?=?5:5–1:9 and β?=?0.5–1.5) were simulated. According to the simulation results, a decrease in δ and β contributed to the formation of an effective axial dust-suppression air curtain in the fully-mechanized excavating region. For eastern belt fully-mechanized working face and those under similar production conditions, an effective axial dust-suppression air curtain can be formed when δ?=?1:9–2:8 and β?=?0.5–0.75. When δ?=?1:9 and β?=?0.5–0.75, the high-concentration dust were blocked in the space in front of the driver of heading machine (i.e., within 7?m from the head-on section), which achieved a better dust suppression effect.     

单面碰撞TMD及其桥梁涡激振动控制研究

单面碰撞调谐质量阻尼器(SS-PTMD)是一种新型减振装置,通过惯性力和黏弹性碰撞进行结构减振,针对SS-PTMD动力性能、碰撞力模型与验证、SS-PTMD桥梁节段模型涡振控制等开展了理论与试验研究。根据质量块单边运动受限和碰撞的特点,获得了SS-PTMD的动力特性;开展了钢-黏弹性材料碰撞试验,提出了碰撞力模型,根据试验数据识别了碰撞力模型参数,并验证了碰撞力模型;通过1∶40桥梁节段模型涡激振动风洞试验,发现+7°风攻角下出现了明显的涡激振动,根据简谐力涡激力模型识别了模型气动参数;采用仿真分析评估了SS-PTMD控制桥梁涡激振动的效果,在质量比2%及最大涡振振幅风速条件下的减振效率达到87%;通过风洞试验研究了SS-PTMD涡激振动控制效果,在质量比2%及最大涡振振幅风速条件下的减振效率达到92%;理论分析和试验结果表明,SS-PTMD对桥梁涡激振动具有很好的减振效果。     

Simulation analysis and engineering application of distribution characteristics about multi-stage atomization field for cutting dust in fully mechanized mining face

To improve the dust suppression efficiency of the external spray systems of shearers, a dust reduction method consisting of shearer external multi-stage atomization and dust removal fan was proposed. Computational fluid dynamics-based numerical simulation was combined with atomization experiments to analyze the migration and distribution of the cutting dust and multi-stage atomization field under airflow at the 2307 fully mechanized mining face of the Tangkou mine. The results show that with adding dust removal fan and multi-stage atomization points, the peak area of wind speed appeared on both sides of the shearer, and the wind speed was greater than 2.7 m/s, the dust concentration on the downside side of the shearer decreased, the spray coverage area increased significantly, and the droplet concentration at the shearer drum was the largest, exceeding 0.05 kg/m³. According to the research results, the multi-stage atomization arrangement of single-fluid water nozzles of shearer was put forward, and the field application was carried out. Compared with the engineering application results of the single-stage atomization dust suppression system, the total dust reduction rate of the synergistic effect of multi-stage atomization external spray with dust removal fan for the shearer is 87.12%, which is 38.59% higher than that of the conventional single-stage atomization dust suppression system.     

Formation mechanisms of a dust-removal air curtain in a fully-mechanized excavation face and an analysis of its dust-removal performances based on CFD and DEM

A high concentration of dust in a fully-mechanized excavation face is a serious threat to the safety of production underground and miners’ health. This paper discusses the use of a novel air curtain generator and proposes a novel dust control and prevention technique. Based on the k-ε two-equation turbulence model, Hertz-Mindlin model and the CFD-DEM coupled interface compiled with C++ language, this paper firstly constructs a simulation model of the coupling between airflows and dust in a fully-mechanized excavation face, and then simulates the airflow fields and dust fields under forced/exhaust ventilation conditions with and without a novel air curtain generator being utilized. The results show that when only the forced/exhaust ventilation was used, a high concentration of dust spread throughout the entire tunnel space and no effective air curtain was formed. Furthermore, after the air curtain generator was turned on, as the radial-to-axial forced air ratio (P_FQ) increased, the horizontal vortex in the front of the head-on section weakened gradually, and the originally disordered airflows behind the heading machine moved uniformly towards the head-on section. As the P_FQ further increased, the distance (d) between the formed air curtain and head-on section decreased overall; through a curve fitting, this relationship can be written as: d = ?5.247 ln(P_FQ) + 13.569. When the P_FQ > 5:5, the average negative-pressure-induced dust-exhaust capacity increased, the distance between the formed air curtain and the head-on section decreased, and the re-entrainment of dust did not take place in a straightforward manner. Finally, some field measurements were carried out in order to validate the simulated results, with the subsequent comparison showing that the numerical simulated results were basically accurate.     

无人机静电喷雾治理开放性粉尘的数值模拟

将静电喷雾技术与无人机技术相结合用于治理开放性粉尘,使用Fluent对粉尘的扩散模型进行数值模拟.模拟得出无人机工作高7m,喷雾压力为0.2MPa时,无人机静电喷雾的平均降尘效率能达到85.87％,并在自然风速为1m/s、空气相对湿度为70％时,局部区域的降尘效率高达95.93％.本文提出的无人机静电喷雾控制开放性粉尘...     

野营折叠网壳结构表面定常风场的数值模拟研究

基于流体动力学基本原理和大气边界层基本理论,运用计算流体动力学软件Fluent6.3对野营折叠网壳结构表面风压分布进行数值模拟技术的基础性研究,对比与风洞试验数据,确定复杂体型结构数值模拟时的计算域尺寸、网格划分方式、网格数量、湍流模型等基本参数设定,得到野营折叠网壳在不同风向角下的表面风压分布及其结构体形系数,同风洞试验结果对比,吻和较好。分析表明风速对结构风荷载体形系数影响较小,而风向角对风荷载体形系数的影响较大;所得结构的体形系数,为类似体型结构的抗风设计提供依据。     

移动型下击暴流及其作用下高层建筑风荷载的数值模拟

下击暴流造成了大量的输电线塔、风机等结构的破坏,对其风场及其引起的结构风荷载研究非常迫切。该文基于RANS,利用SST k-ω湍流模型模拟了下击暴流风速特性及其作用下高层建筑的风荷载。对静止型下击暴流及其作用下高层建筑的风荷载进行了三维定常数值模拟,并将模拟结果与风洞试验结果相对比,结果表明:所建立的CFD计算模型能较好地模拟下击暴流及其作用下高层建筑的风荷载。借助于滑移网格技术对移动型下击暴流进行数值模拟,探究了相应的下击暴流风场及其对位于射流口中心移动路径上的高层建筑的风荷载。将该文模拟得到的移动型下击暴流径向风剖面与实测结果以及其他学者模拟结果相比较,吻合度较高,验证了凭借滑移网格技术能逼真地模拟出下击暴流的风场特性及其作用下高层建筑的风荷载。将静止型和移动型下击暴流的风场特性及其对建筑物的风压作用进行详细对比,研究结果表明:射流口的移动增强了运动方向的径向风速,减小了负方向的风速,并增大了建筑物表面的风压系数,这在结构设计中应予以考虑。