煤矿井下高效喷雾降尘实验研究

发布时间：2018-06-12 02:22

本文选题：表面活性剂 + 表面张力　；参考：《湖南科技大学》2017年硕士论文

【摘要】：煤尘爆炸造成大量的人员伤亡和巨大的经济损失,煤尘的安全隐患和职业健康问题日益严峻。目前,喷雾降尘是煤矿井下最常用的防尘技术措施,然而其喷雾降尘效果较差,尤其是对呼吸性粉尘,因此针对喷雾降尘技术、煤尘的润湿性开展进一步研究,对控制井下作业环境的粉尘浓度,确保煤矿安全生产具有十分重要的意义。论文主要针对以下三个方面进行了实验研究;(1)论文从表面张力、接触角和沉降实验三个方面对表面活性剂与煤尘的湿润性进行实验研究。在表面活性剂溶液中加入高价阴离子电解质(Na2SO4等),通过对其溶液的表面张力测定,发现在表面活性剂溶液中加入高价阴离子电解质能够提高表面活性剂溶液的润湿能力;就不同粒径的煤粉压片进行接触角的实验测定,发现不同粒径的煤粉压片的接触角差异很大,其粒径越小,接触角越大,润湿性越差;同时通过对接触角的测量研究了不同煤质对其湿润性的影响,发现灰分含量越高,其湿润性越强。通过接触角测量和沉降实验分析发现,所选四种表面活性剂对润湿煤尘的效果有差异,其中非离子表面活性剂OP-10在质量浓度为0.005%左右时效果最好。(2)为了分析煤矿井下气水喷雾雾化特性,基于自行设计的气水喷雾试验平台,采用电磁流量计、空气质量流量计及马尔文实时高速喷雾粒度分析仪对空气雾化喷嘴流量特性、雾化粒度的空间分布规律及影响因素开展了实验研究。并就气水混合喷嘴与压力式螺旋喷嘴进行对比,发现气水混合喷嘴具有很明显的优势,在较低的供水压强和供气压强条件下的雾滴粒径D[3,2]就能达到螺旋式喷嘴在超高压强下的雾滴粒径D[3,2],而且耗水量远比螺旋式喷嘴的小,可以很大程度上节约成本,减少资源的浪费。最后就添加表面活性剂对雾化效果的影响进行实验研究,发现在喷雾介质中添加表面活性剂,其喷雾雾滴粒径随浓度增加而缓慢减小,当浓度达到其临界约束浓度后,喷雾的雾滴粒径D[3,2]会随浓度增加而增大。(3)基于可仿真煤矿井下采掘工作面通风、产尘及喷雾等状态的气水喷雾实验系统上,运用实验的方法,针对影响喷嘴喷雾降尘效率的因素开展了研究。通过对比气水混合喷嘴和螺旋式喷嘴在不添加表面活性剂和添加表面活性剂两种情况下的全尘和呼吸性粉尘的降尘效率,发现这两种喷嘴在其雾化特性最好的工况下,其降尘效果也较好,而且气水混合喷嘴的呼吸性粉尘降尘效果比螺旋式喷嘴要好。在添加表面活性剂后,气水混合喷嘴的全尘和呼吸性粉尘的降尘效率都比未添加时的高,降尘效率随表面活性剂浓度的增加而逐渐升高,当浓度达到其临界约束浓度后,降尘效率升高的幅度变缓。综合实验结果,在气水混合喷雾中添加表面活性剂可以增强雾滴表面活性,改善雾化效果,提高降尘效率,为以后喷雾降尘深入研究提供参考。
[Abstract]:Coal dust explosion has caused a large number of casualties and huge economic losses, and the safety risks and occupational health problems of coal dust are becoming increasingly serious. At present, spray dust control is the most commonly used dust control technology in coal mines. However, the effect of spray dust reduction is poor, especially for breathing dust. Therefore, the wettability of coal dust is further studied in the light of spray dust control technology. It is of great significance to control the dust concentration in underground working environment and to ensure the safety of coal mine production. In this paper, the wettability of surfactant and coal dust was studied from three aspects: surface tension, contact angle and sedimentation. The surface tension of surfactant solution was determined by adding high valence anionic electrolyte (Na _ 2SO _ 4) to surfactant solution. It was found that the wetting ability of surfactant solution could be improved by adding high-valence anionic electrolyte to surfactant solution. The contact angle of pulverized coal pressed pieces with different particle sizes is measured by experiments. It is found that the contact angle of different particle sizes is very different, the smaller the particle size is, the greater the contact angle is and the worse the wettability is. At the same time, the influence of different coal quality on its wettability is studied by measuring the contact angle. It is found that the higher the ash content is, the stronger the wettability is. Through contact angle measurement and settlement analysis, it is found that the four surfactants have different effects on wetting coal dust. The Nonionic surfactant OP-10 has the best effect when the mass concentration is about 0.005%. In order to analyze the atomization characteristics of gas-water spray in coal mine, an electromagnetic Flowmeter is used based on the air-water spray test platform designed by ourselves. The air quality Flowmeter and Ma Erwen real time high speed spray particle size analyzer were used to study the flow characteristics of air atomizing nozzle, the spatial distribution of atomizing particle size and the influencing factors. By comparing the air-water mixing nozzle with the pressure spiral nozzle, it is found that the air-water mixing nozzle has obvious advantages. Under the condition of low water supply pressure and air supply pressure, the droplet diameter D [3N 2] can reach the diameter D of the spiral nozzle under the super high pressure, and the water consumption is much smaller than that of the spiral nozzle, which can save the cost to a great extent. Reduce the waste of resources. Finally, the effect of adding surfactant on the atomization effect was studied. It was found that the particle size of spray droplet decreased slowly with the increase of concentration, and when the concentration reached its critical confinement concentration, the spray droplet size decreased slowly with the increase of the concentration of surfactant in the spray medium. Spray droplet diameter D [3N 2] will increase with the increase of concentration.) based on the air-water spray experimental system which can simulate the ventilation, dust production and spray of underground mining face, the experimental method is used. The factors influencing the efficiency of spray dust removal were studied. By comparing the dedusting efficiency of total dust and breathing dust between air-water mixed nozzle and spiral nozzle without surfactant and surface active agent, it is found that the two nozzles have the best atomization characteristics under the working conditions. The dust control effect of the air-water mixing nozzle is better than that of the spiral nozzle. After the addition of surfactant, the dust removal efficiency of the air-water mixing nozzle was higher than that of the non-added nozzle. The dust removal efficiency increased gradually with the increase of surfactant concentration, and when the concentration reached its critical confinement concentration, the dust removal efficiency increased gradually with the increase of surfactant concentration. The extent of the increase in dust reduction efficiency has slowed down. The experimental results show that the surface activity of droplets can be enhanced, the atomization effect can be improved and the dedusting efficiency can be improved by adding surfactants to the air-water mixed spray, which provides a reference for the further study of spray dust control.
【学位授予单位】：湖南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD714.4

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