【作者】 李刚；

【导师】 邹声华；

【作者基本信息】 湖南科技大学 ， 供热、供燃气、通风及空调工程， 2009， 硕士

【摘要】 工业粉尘污染是安全生产和环境保护的瓶颈问题。随着绿色安全生产的轨道化,粉尘治理日益成为环保工作的重点。目前,人们从产尘机理、降尘机理到降尘技术等方面进行了广泛的研究,研究成果对粉尘的防治起到了一定的促进作用,但粉尘治理问题还未从根本上得到解决,如降尘效率低、成本消耗大等。因此,在现有技术的基础上,不断研究新的高效降尘技术是关系到改善环境、保护人民生命安全与健康、文明生产、降低生产成本、顺利发展生产的一项重要工作,因此,本论文开展高效水雾降尘技术的研究具有十分重要的意义。水雾降尘技术是治理开放性粉尘最简便、最经济的方法,但实际应用效果并不理想。其主要原因有以下几个方面,一是水雾的形成受现有技术的制约,大多采用喷雾技术,对喷雾降尘的理论缺乏详尽研究,还不能定量描述喷雾降尘的机理,导致应用技术的盲目性;二是喷雾系统参数不尽合理,特别是雾滴直径与粉尘粒径的良好匹配难以确定,影响了喷雾降尘效果;三是喷雾降尘过程还不能微观测量,新技术的开发受到了局限。为解决上述问题,本文借助流体力学、空气动力学和气溶胶力学理论及其它相关理论,在水雾形成、水雾降尘机理和影响水雾降尘效果的诸多因素等方面,采用理论推导、实验室实验和现场试验相结合的方法对水雾降尘技术进行研究,设计出了一种经济的高效水雾降尘方法,现场应用取得了较好的降尘效果。主要研究内容有以下几个方面。(1)对比研究各种水雾产生方式。对喷雾除尘技术进行系统理论研究,分析其捕尘理论。研究喷雾效果与各雾化参数的相互关系,寻求喷雾除尘的最佳匹配参数,提高对呼吸性粉尘及全尘的沉降率。采用压力型喷嘴产生水雾时,除尘效率主要取决于供水压力,不同粒径的粉尘需要的水压力不同。压力越大,喷嘴直径越小,雾滴越细,对于微细粉尘的除尘效果越好,然而,不同粒径的粉尘颗粒有不同的最佳水雾粒度。然而,水质不好,或使用环境差时,喷嘴容易堵塞,影响喷雾效果。另外,喷雾流容易受风流干扰,也影响除尘效果。本文提出喷射流自激雾化降尘技术,并对此进行了探讨。(2)采用降尘剂喷雾降尘,提高雾滴对粉尘的捕集能力,主要研究降尘剂溶液表面张力与降尘剂浓度的关系,湿润速度与降尘剂浓度的关系,以及水量、水压与除尘效率的关系等。(3)针对湘潭钢铁公司某料场装载机工作系统的现场情况,提出并使用喷射流自激雾化降尘技术,取得了良好的降尘效果。(4)微细水雾有利于呼吸性粉尘的捕集。对于微细水雾捕尘,因粉尘与捕尘水滴粒径都较小,需采取一定的措施加强颗粒间的碰撞结合、凝并沉降。本文在压力型喷嘴喷雾降尘技术的基础上进行发展,提出了喷雾帷幕降尘技术,并对此进行了探讨。综上所述,本文采用湿润型降尘剂水雾对细微粉尘及全尘去除率进行研究,具有良好的净化效果,同时提出了喷雾帷幕降尘技术和喷射流自激雾化降尘技术,这为我国在处理粉尘污染方面提供一条有效的治理途径。更多还原

【Abstract】 Industry dust pollution has become one of the main obstacles for the safety production and environmental protection. With normalized business of green safe manufacture, dust control has been increasingly become the focus of environmental protection work. Although exsiting research about dust production mechanism and promotion of dust-settling technology have done some thing to prevent dust pollution, but dust pollution problem has not been resolved. So while we are using exsiting technology, we have to study new dust-settling technology. Dust-settling work relates environment improvement, safety and the health of the people, the enlightened production, the production cost reduction, and a smooth development production. So, it is extremely significant to develop the reseach of the efficient water spraying dust-settling technology.Water spraying dust-settling technology is an economical and simple way to control open dust, however, its actual application effect is unsatisfying and inefficient, and it has great comsuption. The main reasons are as follows: the first one is that the formation of water spraying is restricted by technology and theoretic research on spray dust-controling is not comprehensive, and it is difficult to match the droplet diameter with the dust size, which leads to blind application; The other is that the unreasonable parameters of spray system affect the spray dust-settling effect; The third is that the process of spraying dust-settling can not be observed by microscopic means and the developing of new technology is restricted. In this thesis, for solving the above problems, through research on water spraying, water spraying dust-controling and factors influencing water spraying dust-controling effect, by aid of hydromechanics, aerodynamics and aerosol mechanics as well as some other corresponding theories, by means of conbining theoretical derivation, laboratory experiment with field investigation, the research on spray dust-controling is carried out, an economical and efficient method of water spray dust-controling is schemed out, and the dust laying effect is much satisfying in fied application. The main research contents are as follows.(1) Contrastive study of the formation of water spraying. The systematic theoretic research on the spray dust-controling analyze out the dust-catching theory. Research on the relation between spray effct and every atomization parameters find out best matching parameters of spray dust abatement, and to promote the sedimentation rate of respiratory dust and total dust. It was obtained that the smaller the water fume is, grain the higher the efficiency of reducing dust, and different diameter dust grain has a relevant best water fume grain. When a dopting pressure type atomized spray nozzle to reduce float dust, the efficiencymainly depends on water pressure. Different diameter dust grains need different water pressures. However, some exogenous conditions can influence dust removal effect, such as bad water quality, inferio application environment and interference of airflow. This paper proposes and discusses water spraying dust-settling technology of self-impingement liquid jet.(2) Dust laying spray with dust agent is used for enhacing fogdrops’ ability to trap dusts. Most research on relation between surface tension of dust agent solution and concentration of dust agent, relation between mosit speed and concentration of dust agent, as well as relation between water volumn, hydraulic pressure and efficiency of dust collection etc.(3) Focus on on-site situation of dust in the shovel loader work system of Xiangtan steel company, spray dust-controling system is taken, and it makes good dust-controling effect.(4) Fine water-spray makes for capturing respirable dust.as to fine water-spray dust-catching, some certain measures must be adopted to enforce combination of collision, condensing and falling between particles, because grain diameter of dust and dust-catching waterdrops. This paper proposes and discusses the water spraying film dust-settling technology based on the water spraying dust-settling technology by pressured mist nozzle.To sum up, in the thesis, the removal percentage of respirable dust and total dust arereseached with water-fog-dust-agent, and it proposes the water spraying film dust-settling technology and the water spraying dust-settling technology of self-impingement liquid jet. This way makes better purification effect, therefor, it provides an efficient approach to control dust pollution.更多还原