对云锡公司红旗坑2250中段与塘子凹坑进风井能否贯通的看法

1 问题的提出 云锡公司马拉格矿塘子凹坑1950中段至红旗坑2340中段的进风井,垂高390m,井筒直径3.2m,打通后,形成了对角式通风系统,改变了塘子凹坑通风不良的状况。以后,在1950中段进风井井底车场安装了1台75kW的风机作压入式进风,在2000中段回风井也安装一台75kW风机作抽出式回风,形成压抽混合式通风方式。各工作面和用风地点都安装了局部风机（共70多台）,形成局部通风系统。 红旗坑2340中段的通风,主要通过安装在2340中段的一台55kW的主扇,新鲜风从2340坑口压入,再通过2台辅扇,16台局扇形成压入式通风。污风从1~#矿群回风道回风,也有从采空区回风的。     

沛城煤矿进风井风流反向原因分析及治理

1 问题的提出 沛城煤矿为小型矿井,采用竖井下山开拓,中央混合抽出式通风。中央风井安装2台4-72-11№20B离心式通风机,1台运转,1台备用。中央风井回风风量24m~3/s左右,扇风机房水柱计读值1.079kPa。东风井安装4-72-11№16B离心式风机,风量约16m~3/s,水柱计读值2.511kPa。 该矿主井与副井闭合回路的局部通风系     

是谁拿命开玩笑——来宾煤矿瓦斯爆炸事故分析

1998年 11月 2 9日 ,云南省宣威市来宾煤矿二号井发生瓦斯爆炸事故 ,42人丧生。在死难者中 ,年纪最大的 3 5岁 ,最小的才 2 0岁。一来宾煤矿位于云南省宣威市东北 14公里处 ,始建于 195 8年 ,属全国 3 6家特困煤炭企业之一。二号井的生产能力为年产煤 3 0万吨 ,斜井开拓 ,主井箕斗提升运煤 ,副井串井提升 ;矿井为分区通风 ,共装有离心式风机 6台。该矿井为低瓦斯矿井。井下主采区为 1780水平北翼下山三采区。上半年已准备好的 3 3 0 4工作区因遇规模较大断层而无法开采 ,故被迫在尚未准备好的 3 3 0 5工作区进行前进式开采。当推进到 72米时…     

FS系列风机在狮子山铜矿通风系统改造中的应用

一、通风系统现状狮子山铜矿为竖井开拓,分为三个分区:东山、西山、老鸦岭.该矿采用多井口、多风机联合作业的多翼对角式抽出式通风,根据开拓系统的实际情况,通风系统分为东山,西山和老鸦岭等三个分区。通风系统安设了三台主扇,总装机容量670kW,实测主扇总功率为439.70kW,年耗电量约290多万kWh。这个通风系统存在以下问题: (1)东西回风井断面小,回风阻力大: (2)采空区较大,且部分地表已塌陷,     

FSC—18型节能风机在我矿的应用

辅扇在我矿的应用,主要用于小分区回风系统的排风和阻力大的分支回路的辅助通风。我矿二期扩建后,为解决东部2#群区域的污风排出问题,曾采用2台JBT-28kW风机并联抽出,但风量较小,仅13m~3/s,满足不了通风要求,且能量消耗较大。1986年起改用K系列风机。风量增加到16～28m~3/s,能耗降低30％,基本解决了该区域的通风问题。南部2#风井主扇由于受二氧化硫气体腐蚀和排风道碎砂磨损,机体严重损坏,叶片更换频繁。加上农民在上部闭坑中段采矿损坏通风构筑物,造成上部中段大量漏风,下部作业中段风量减少,通风困难。为了解决     

某矿独头工作面炮烟中毒事故分析

某矿为平窿与盲竖井联合开拓,采用主平窿进风,主风井回风的对角抽出式通风系统。主扇是一台70B_2-2№18#(电机容量310kW)轴流式风机。四中段以上为主风流系统,五、六中段正在开拓,没有形成主风流。独头掘进工作面依靠局扇通风,一般采用混合式布置。     

泗顶铅锌矿多风机多级机站通风系统优化的研究

为改善泗顶铅锌矿井下作业条件,对该矿南矿通风系统进行技术改造,要求采用新技术、新设备,建成一个安全可靠又满足通风要求且节能的通风系统。南矿的通风方式为单一抽出式,风流由主平峒经斜井进到230中段后,通过自然分风经各人行井到240、250、260、270各中段,由总回风井(南风井)排出地表。地表装有二台70B_2-21-№18风机,电机分别为210kW和180kW,交替使用,实测风量为46.0m~3/s,效率为23.70％。调查测定表明,由于作业中段多,作业面分布较广,采空区大又互相联通,造成南矿通风系统有效风量率低,内部漏风严重,采场电耙处风量不足,风机效率过低。通风系统的改造,将有助于提高有效风量率,排出炮烟粉尘,改善作业条件,保护工人的身     

铸造车间的净化

美国新泽西州研磨机械公司最近在俄亥俄州代顿市的代顿钢铁公司铸造车间安装了一套空气净化装置。据称,这套净化装置能把炉子散发出来的灰尘除掉99.7%,其工作流程见附图。 这套净化装置设有八座过滤器,每座过滤器配备一台40马力的风机和216个用的确凉织物做的滤袋。每座过滤器每分钟可处理10000立方英尺、温度高达华氏 275°(摄氏132°)的空气。滤袋直径为5英寸,长15英尺。主管道直径为5英尺,通过空气的流速为每分钟4000英尺。如果管道内的温度超过华氏250° (摄氏121勺,此时来自大气的冷空气就由阀门流人员节。每座过滤器和主管道连接处均…     

某印染厂SHL20—2．45／400锅炉过热器爆管原因分析

2005年嘉兴市某印染厂新安装了1台型号为SHL20—2．45／400的双锅筒横置式链条锅炉．该炉投产后半年内先后共有13根低温过热器管爆管．被迫停炉大修。本文根据调查和试验，对低温过热器爆管的一些原因进行探讨分析。     

测量四种通风参数的携带式仪器

为监测氡气,美国矿山局,装制了一台四种参数的测量仪,以便精确地确定矿井空气的相对湿度、温度、气压和风速。这种新仪器装在手提箱里,外形尺寸为17×20×8英寸,净重不超过15磅测量矿井空气的相对湿度用H—5型湿度计。这个组件有一个S型曲线的非线性输出,并可使之线性化,以便在计数器上的湿度读数可达到±3％的精度。测量温度采用Rdf公司21701—121铂电阻探头和放射仪表4001—100信号调节组     

徐庄煤矿主要通风机性能测定及分析研究

系统介绍矿井主要通风机的测试过程及相关方法,并以徐庄煤矿的风机测定为例,应用合理的测试及计算方法,进行相关参数的计算并绘制风机性能曲线图;同时,对主通风机出厂曲线和风机初始安装性能曲线进行对比,得出徐庄煤矿主要通风机的运行变化规律,为保证其安全高效运行和风量调节提供可靠的理论依据。对测定结果进行总结、对比和分析的同时,还提出应注意的问题。     

同忻井田地应力测量与回采巷道稳定性研究

为保证同忻煤矿安全、高效开采,采用应力解除法对大同矿区同忻井田3-5#煤层的地应力场进行了测量,结合理论分析、数值模拟与现场监测,分析了在该类型应力场中不同巷道布置方向与巷道围岩稳定性之间的关系。测得同忻井田最大主应力为20.42 MPa,方位角为245.18°,确定了同忻井田地应力场属于σHv型。理论计算和数值模拟的结果表明,有利于回采巷道稳定性的布置方向为与最大水平主应力方向成30°,并采用巷道顶板离层监测仪对其进行了验证。     

基于Markov过程理论的矿用通风机系统可靠性研究

结合矿井通风系统中通风机分支系统实际,依据可靠性工程理论中Markov过程理论及相关知识,探讨了矿井通风机系统可靠性分析的新方法;推导出了通风机系统的可靠度及首次故障前平均寿命的计算公式;结合现场实际,进行了实例验证;根据通风机系统可靠性各项主要指标数据,分析了影响通风机系统可靠性的因素.为现场通风技术管理人员进一步掌握矿井通风机的可靠性运行状况提供了参考依据.     

An automatic approach for the control of the airflow volume and concentrations of hazardous gases in coal mine galleries

Intelligently controlling ventilation networks after an abnormal air branch is difficult. The key variable-frequency mine ventilator control factors that are used to correct this phenomenon were discussed. To improve the fitting accuracy of the mine ventilator characteristic curves, a database of characteristic curves for mine ventilators operating at different frequencies was established using the interpolation method for optimizing uniform approximations by Chebyshev. The concept of frequency sensitivity analysis by analyzing the sensitive branch in the ventilation network was proposed. The linear function between the mine ventilator working frequency and branch wind quantity was fitted out by experiments. A model based on Tikhonov regularization measured the branch wind quantity to calculate the wind resistance in the ventilation network, which yielded a unique branch resistance model solution. The mine air was monitored by calculating the variable wind resistance from the branch wind quantity. The sensitive branch coupling in the mine ventilator variable-frequency controlled ventilation was analyzed and combined with the control theory for ventilation networks. Two types of variable frequency were controlled to adjust the branch wind quantity, the frequency-concentration (f-w) servo control method and the curve search method. The experimental model was established for the Da Liu-ta coal mine ventilation system using the mine ventilator variable-frequency system controller to adjust the branch wind quantity. Because gas is explosive, CO₂ was used instead of gas for this experiment. The results indicate that the mine ventilator variable-frequency control automatically adjusted the branch wind quantity, which strictly followed the frequency-concentration servo control method and curve search method. Increasing the CO₂ concentration caused the mine ventilator variable-frequency controller to increase the branch wind quantity automatically to maintain the CO₂ concentration under the threshold value. The experimental results also demonstrated both the practicability of variable-frequency regulation for air branch systems and the feasibility of the branch quantity adjusted theory. Theoretical guidance for adjusting the ventilation branch quantity for a variable-frequency mine ventilator was provided.     

某山坡露天矿边坡稳定性的FLAC3D研究

某山坡露天矿,原设计的最终边坡角约为46°。为了探索最终边坡角的合理性,应用快速拉格朗日有限差分法FLAC3D在摩尔-库伦准则下搜索该岩质山坡露天边坡的潜在受拉区,判定其稳定性。结果表明:经济合理的最终边坡角是50°38';应用8 m长的锚索加固局部台阶可减小其潜在受拉区中的拉应力;并段将减小边坡的稳定性;爆破开挖时的同段最大装药量与爆距对边坡稳定性影响明显。该方法确定最终边坡角技术可行,它适用于研究岩质边坡的稳定性,克服了用极限平衡法研究边坡稳定性必须事先假定滑动面的弱点。     

金川公司二矿区矿井火灾救灾决策支持系统研究

井下属于受限空间,一旦发生火灾,避灾和救护都比较困难。发生矿井火灾时,火灾参数不易测定,但在制定火灾应急救援预案时,则是必须考虑的问题,因此,数值模拟就成为一种分析矿井火灾的有力工具。笔者利用地下工程火灾理论,从流体网络的角度给出了污染范围的确定及最佳避灾路线的数学模型;从实用的角度出发,根据金川公司二矿区的具体情况,构建了金川公司二矿区矿井火灾救灾决策支持系统;可为火灾时期火情预测、避灾、救灾及制定火灾应急救援预案提供支持。     

Pilot sample risk analysis for underground coal mine fires and explosions using MSHA citation data

After three decades of sustained continuous improvement of mine safety performances in the US, mine disasters in 2006 and 2007 compromised an excellent record and presented new challenges and vulnerabilities for the underground coal mining industry. In the aftermath of the incidents, formal investigations and new scrutiny of mine safety by the US Congress and expert study groups followed. The US Congress passed the Mine Improvement and New Emergency Response Act of 2006 (MINER Act), which mandated new laws to address the issues, including those related to mine fires and explosions from which miners must be protected. The National Mining Association-sponsored Mine Safety Technology and Training Commission report highlighted the role of risk analysis and management in identifying and controlling major hazards, such as fires and explosions. In this paper an approach is given for analyzing the risks for fires and explosions based on the Mine Safety and Health Administration citation database. Using 2006 citation data and focusing on subsystem failures, the methodology is applied to a database for a pilot sample of underground coal mines stratified by mine size and state.     

Sources of underground CO: Crushing and ambient temperature oxidation of coal

As a harmful gas in underground coal mine, CO seriously threatened the safety of miners. Currently, the spontaneous combustion of residual coal in goaf is generally considered as the main source of underground CO. CO gas is also widely used as an indicator gas in fire prediction in mines. However, high concentrations of CO are also detected in some mines without spontaneous combustion of coal. Therefore, in the paper, with four ranks of coal, we studied other two potential CO sources: crushing and oxidation at ambient temperature. The more completely crushed coal produces more CO. The concentration of generated CO is inversely proportional to moisture content in coal. Therefore, the addition of water can inhibit the generation process of CO during the crushing process of coal. Lignite with low metamorphic grade can be oxidized to produce CO at ambient temperature (25 °C), and anthracite with high coal rank can be only oxidized to produce CO at 60 °C. Infrared spectra indicated that the coal with rich aliphatic hydrocarbons and oxygen-containing functional groups are more susceptible to oxidation at room temperature. Moreover, the smaller particle size of coal is more beneficial to the oxidation at ambient temperature to generate CO. CO generation during coal oxidation is also closely related to the ventilation rate.     

Low temperature autoignition of Jet A and surrogate jet fuel

An experimental study of the low-temperature and low-pressure autoignition of Jet A and surrogate fuels was conducted using the ASTM-E659 standardized test method. Two surrogate fuels (Aachen and JI mixtures), their individual components and two batches (POSF-4658 and POSF-10325) of standardized Jet A were tested using the ASTM-E659 method for a range of fuel concentrations and temperatures. The ignition behaviors were categorized into four distinct ignition modes. The individual hydrocarbon components had a wide range of ignition behaviors and minimum autoignition temperatures (AIT) values depending on the molecular structure. The two Jet A batches showed similar ignition behavior with measured AITs of 229 ±3°C and 225 ±3°C respectively. Both surrogates exhibited similar ignition behavior to Jet A with comparable AITs of 219 ±3.1°C (Aachen) and 228 ±3°C (JI) with the JI mixture proving to be a more suitable surrogate to Jet A in the low-temperature thermal ignition regime.     

Response of the Head,Neck and Torso to Pendulum Impacts on the Back

Pendulum impacts on the back were conducted to determine human head, neck and torso biomechanics. Eight unembalmed cadavers were subjected to 23.4 kg pendulum impacts at 4.4 m/s and 6.6 m/s at T1 and T6. Twenty-four tests were conducted with accelerometers on the pendulum, spine, torso, and head in the WSU 3-2-2-2 array. High-speed photography was taken. Impact displaces the torso forward, deflects the chest, displaces and rotates the head, and extends the neck. Average responses and corridors were determined for head kinematics and chest force-deflection. The head-neck response occurs in two phases. First, the head displaces upwards and rearwards 30—40 mm with respect to the torso along a 45° trajectory. Head rotation is 1O°-15° with essentially no neck moment, but high neck compression forces. Second, the head rotates from 10°-15° to 40°-55° starting with a rapid rise in neck moment and displaces 80–100 mm rearward. Anterior cervical fractures correlate with neck tension. Rib fractures correlate with impact force and chest deflection. This study provides chest bio-mechanical responses for rear impacts resulting in head displacement and rotation, neck extension and cervical-thoracic injury.