The fully-mechanized mining face is a key site for coal mine dust control. For some fully-mechanized mining faces with a large mining height, the massive amount of fine dust generated by coal-cutting shearer drum and lowering column and moving frame of hydraulic support tends to diffuse to the upper working face and float at high levels. To reduce the pollution at working face, this study innovatively proposed a novel method combining dust extraction at top support beam and pneumatic micro-mist dust removal. Combining the numerical simulation with a three-dimensional high-fidelity solid model and the underground test of the negative-pressure dust removal and micro-mist purification technology, the influence of air volume on the airflow and dust migration and distribution at the working face was analyzed in detail. It was concluded that the floating dust settlement at the working face was the most remarkable when the air volume of the dust collectors was 120 m~3/min and their spacing was 35 m. Based on these key parameters, a dust remover integrating powered dust extraction and micro-mist removal was independently developed. An experimental system was established to test the performance of the developed dust remover, revealing that the dust reduction efficiency averaged 98.31% and 95.29% for total dust and respirable dust, respectively. The device was applied to the 22408 fully-mechanized coal face of the Shendong Bulianta coal mine of China Energy Investment Corporation. The field test results showed that the total dust reduction efficiency at the working face exceeded 80% and the respiratory dust reduction efficiency surpassed 70%. The total dust concentration in the respiratory zone of the pedestrian area was reduced to below 15.3 mg/m~3,and the respiratory dust concentration became less than 10.3 mg/m~3. The proposed dust remover effectively solved the problem of high-level floating dust pollution in the fully-mechanized face with a large mining height and greatly improved its working environment, providing a new way to create a safe, healthy, and green coal mine production environment.

针对曹家滩122109综放工作面采煤机滚筒截煤产尘严重、粉尘扩散速度快的问题,在详细调研的基础上,重新优化设计了 一系列喷雾,主要包括煤机上风侧L形喷雾、采煤机控降尘喷雾、机面顺风喷雾、机面集中喷雾、破碎机护罩喷雾和破碎机挡板喷雾,实现了对采煤机尘源的高效抑、控、降尘.现场应用结果表明:优化后的采煤机喷雾对司机处的总粉尘降尘效率达到67.50％,呼吸性粉尘降尘效率达到56.95％,极大地改善了现场工作环境,并且现场视线清晰,无水雾现象产生.

In order to study the influence of the internal structural parameters of the gas-water nozzle on the atomization performance, the atomization characteristics of the nozzles with different structural parameters were analyzed based on the self-built test platform and the Doppler laser fog particle counter, and field test verification was carried out. The research shows that when the water pressure is constant, with the increase of the air supply pressure, the size of the three key internal structural parameters of the nozzle and the air consumption, and the range of the nozzle gradually increase; the larger the diameter, the wider the range of particle size distribution, and the smaller the proportion of small-sized particles. At the same time, when the diameter of the air cap is constant, appropriately increasing the diameter of the air passage and water passage can optimize the atomization effect; the 4# nozzle with the best atomization effect in the test results is carried out in the underground coal mine field test, and it is concluded that the dust reduction efficiency at the side of the driver and 15 m to 20 m on the downwind side of the shearer is 61%, 62%, 62%, and 63% respectively, showing good dust reduction effects.

针对大采高综采工作面支架间人行道粉尘污染严重的问题,以补连塔煤矿12513工作面为研究对象,通过现场调研,得出降柱移架的主要产尘点.基于封闭控尘原理,优选出U形结构作为封闭控尘装置的主体,并采用滑轨补偿移架位移的方式设计了一种新型的支架滑移式封闭控尘装置,并对其有效性和可靠性进行了现场试验.现场应用表明,该装置粉尘降尘效率达92％以上,显著改善了大采高工作面有人作业区域的环境卫生条件.

大采高综采工作面生产效率高、产能大,粉尘污染问题严重.为解决大采高综采工作面现有喷雾降尘措施效果不佳的问题,以红柳林煤矿24205工作面为工程背景,在分析大采高综采工作面采煤机割煤产尘特点的基础上,通过高压喷雾降尘工艺参数优化,重点开展了采煤机高压外喷雾降尘技术、尘源跟踪喷雾降尘技术的应用研究,解决了喷嘴堵塞、喷雾量不足、喷雾射程短、覆盖面积小的问题,实现了滚筒割煤过程中尘源处的立体覆盖式喷雾.应用结果表明:采煤机司机处总粉尘和呼吸性粉尘平均质量浓度分别从1362.4、289.1 mg/m3降低到97.4、31.7 mg/m3,降尘效率分别为92.85％、89.02％;采煤机下风侧10 m处总粉尘和呼吸性粉尘平均质量浓度分别从456.8、97.3 mg/m3降低到45.1、9.7 mg/m3,降尘效率分别为90.13％、89.76％.工作面作业环境得到了明显改善.

针对采煤机割煤过程中的粉尘污染问题,遵循"先抑、后控、再降"的治理思路,提出了利用高效抑尘喷雾快速湿润破碎煤体,再利用控尘喷雾控制含尘气流沿煤壁一侧运移,最后利用机载喷雾引射除尘器沉降粉尘的综合治理措施.采用实验室实验和现场试验相结合的方法,重点开展了支架顶部组合喷雾抑尘、采煤机喷雾控降尘、采煤机机载除尘等关键技术及装备的研究,并在高产尘强度综采工作面进行了应用,将采煤机正常割煤时司机处的总粉尘质量浓度由3097.0 mg/m3降至52.6 mg/m3,取得了显著的降尘效果.

Abstract In order to solve the problem of high dust concentration in fully mechanized top-coal caving face with difficult wetting and high dust production, a combined water injection test of “long period static pressure, alternating dynamic static pressure and static pressure in stress-affected zone” was carried out in Wangjialing Coal Mine with the engineering background of fully mechanized top-coal caving face in 20107 and combined with the previous water injection test and field actual situation. By comparing and studying the wetting and dust-reducing effects of different water injection methods and borehole spacing, the water injection process parameters suitable for this kind of coal seam are obtained. The field practice shows that the wetting radius can be increased to 3 m by the combined water injection process. In the water injection area with 5 m drilling spacing, the total dust removal efficiency can reach 57% and the respirator dust removal efficiency can reach 70%. It can effectively solve the dust hazard problem of the working face, and the effect is re-markable.

Aiming at the serious dust pollution problem at the shearer driver position while coal cutting by the shearer against wind,based on the analysis of dust generation and migration laws and the relevant theory of spray jet,a technical measure of using ejection spray and dust curtain to control dust-laden air flow around the shearer was put forward,and study was carried out on its control principle and effect through theoretical analysis and field tests.The results showed that under the optimum parameter conditions,using this technology can effectively control dust-ladden air flow around the shearer to move along the coal wall side,and the total dust and respiratory dust concentrations at the shearer driver position in the fully mechanized coal face can be respectively reduced by 91.3％ and 88.5％.

基于综掘工作面分步立体式控降尘系统在现场应用中出现的不足之处,对系统中掘进机环形外喷雾装置及通风除尘用吸尘罩的结构进行了优化,并选用了更加简便的调风控尘装置工艺配套方式,在保证了系统原有控降尘效果的同时,极大地提高了系统在井下恶劣作业环境中的适用性及可靠性.

我国商业地产融资模式单一,对银行资金的依赖性过大,难以满足商业地产巨额的资金需求.这一方面是因为我国金融市场发展滞后于房地产业的发展,融资渠道单一;另一方面也与我国目前商业地产供给过剩,商业地产自身资金需求量大、投资回报周期长、风险较大有关.为了解决我国商业地产融资困境,本文建议可以加大对以下五种融资模式的应用:房地产金融租赁、互联网融资、房地产投资信托基金、房地产私募基金、典当.这几种新型的融资模式,对解决我国商业地产融资难的问题,起到了非常大的作用.

Based on the statistical analysis of dust concentrations in the fully mechanized heading face,discussion was made on the variation rule of dust concentration at the heading machine driver position with the height of the cutting head,and study was carried out on the dust movement and settlement in the heading face and the dust diffusion regularity in the horizontal and longitudinal sections.It came to the conclusions that the largest amount of dust generated while the heading machine cut the top coal,the dust concentration in the three areas did not uniformly distribute,and the respirable dust amounted to a large proportion and settled down difficultly.Corresponding proposes and measures for dust control were put forward according to the dust generation and movement law,and the reference basis were provided for the dust prevention and control in the fully mechanized heading face.

在分析采煤机割煤产尘特点的基础上,根据两相流理论建立采煤工作面粉尘运移的离散相数学模型,设定不同的边界条件,得到不同巷道风速情况下采煤机逆风割煤时前滚筒垮落产尘时粉尘浓度的分布,并分析得到高风速综采面采煤机产尘的运移规律.据此有针对性的开展采煤机含尘气流控制及喷雾降尘技术的研究,并在实验工作面进行现场应用,结果表明,降尘效率可以达到90％.

The weakly expansive nonGshrinkage grouting materials were applied to borehole sealing by water inj ection?The adj ustment of corresponding technical parameters guaranteed the sealing effect and enhanced the wetting degree of coal mass by water inj ection?The field applicaG tion showed that the total dust falling efficiency increased from 25?0 % to 40?0 % and the respirG able dust falling efficiency rose to 47?9 % from 33?2 % after borehole sealing by nonGshrinkage grouting materials at the working face.

By taking the fully mechanized heading face of 20105 auxiliary haulage way in a coal mine of Shanxi Huajin Energy Co. , Ltd. , as the research object and using the methods of numerical simulation and field measurement, the dust concentration distribution in the heading face was obtained, the dust migration law in the process of coal cutting by the tunneling machine was analyzed and summarized. Corresponding measures such as water infusion in seam, high-pressure outer water spraying, regulating duct location, dust collector and dust capture net were proposed for comprehensive dust control. The site application results showed that the total dust suppression efficiency at the operator position and in the place 10m behind the tunneling machine respectively reached 96. 2% and 98. 2%.

Analysis was made on the air flow distribution and dust concentration distribution in different distance from the air duct outlet to the heading face by taking 20105 heading face of Wangjialing Mine as the research object and by means of the numerical simulation, the variation regularity of the dust concentration with the air flow distribution in the heading face and the optimal distance from the air duct outlet to the face were obtained according to the site measuring results, and the spray pressure, flow-rate and direction of the high-pressure external spraying system on the heading machine were accordingly optimized. The practice showed that the total dust removal efficiency at the machine operator reached 88. 4%, the respirable dust removal efficiency reached 82. 6%;the total dust removal efficiency at 10m place behind the heading machine reached 89. 9%, and the respirable dust removal efficiency reached 85. 1%.