多层级喷嘴对置式洗涤塔对粉尘颗粒脱除特性的研究

发布时间：2019-04-24 03:56

【摘要】：日益严峻的粉尘污染已经成为制约我国大气环境质量的瓶颈问题。近年来,我国社会经济和城镇化进程得到了高速的发展,但人们赖以生存的大气环境却受到了严重的破坏。因此,粉尘治理问题已经成为社会各阶层广泛讨论的话题和环保学家研究的重要课题。目前,人们对各类除尘器的除尘机理已经进行了深入的研究,所取得的成果对于大气环境治理起到了一定的促进作用,但是并没有从根本上解决除尘器降尘效率低、高能耗、成本消耗大、结构复杂等问题。因此,本文在现有湿法除尘技术的基础上,提出采用多层级对置喷雾的方式解决传统湿法除尘存在的效率低、水耗大、耗能高等问题,对于除尘技术的研究具有十分重要的意义。以往对于喷雾除尘的研究大多关注其总的除尘效率,而忽略了喷雾压力变化导致的雾化粒径变化对除尘效率的影响。因此本文在传统喷雾除尘机理的基础上,采用图像测量技术对喷嘴的雾化粒度进行测量,所得结果显示雾化粒径变化的总趋势为:随着喷雾压力的升高,平均雾化粒径逐渐减小。当喷雾压由0.2MPa提高到0.4MPa时,平均雾化粒径的变化幅度较大,由456μm下降到219μm,呈近似线性关系;当压力在0.5~0.6MPa变化时,平均雾化粒径的变化较为平稳,由176μm下降到165μm。重复多次测试喷雾压力与水流量之间的对应关系,其结果显示喷雾压力由0.1MPa上升到0.8MPa时,对应洗涤水的平均流量由0.6L/min上升到2.1L/min,上升曲线呈线性趋势。本文通过搭建多层级对置喷雾洗涤塔实验台,根据喷雾粒度实验所得结果,以空气、水和粉尘颗粒作为介质,研究了多层级喷雾洗涤塔内液气体积比、塔内气体平均流速、粉尘浓度、喷雾压力等参数对除尘效率的影响规律。研究结果表明:洗涤塔内喷雾层数对除尘效率的影响最为显著,与传统的单层相比,除尘效率可以提高15%以上;并且在实验条件下,入口粉尘浓度的变化对其除尘效率的影响较小;增大喷雾压力可以有效提升除尘效率,当喷雾压力为0.5~0.6MPa时,除尘效率变化趋于稳定;在相同操作参数下,适当降低气体在塔内平均流速有利于提高洗涤塔的除尘效率,对于三层喷雾洗涤,最佳的气体塔内平均流速为0.6~0.8m/s;当喷雾压力为0.6MPa、塔内气体平均气速为0.6m/s、液气体积比为5.27、入口粉尘浓度为16g/m3的条件下,三层喷雾除尘的效率可以达到98.3%。
[Abstract]:Increasingly severe dust pollution has become a bottleneck problem restricting the quality of atmospheric environment in China. In recent years, China's social economy and urbanization process has been developed at a high speed, but the atmospheric environment that people rely on for survival has been seriously destroyed. Therefore, dust control has become a widely discussed topic in all levels of society and an important topic studied by environmentalists. At present, the dedusting mechanism of all kinds of precipitators has been deeply studied, and the results obtained have played a certain role in improving the atmospheric environment, but they have not fundamentally solved the low dust reduction efficiency and high energy consumption of the precipitators. Large cost consumption, complex structure and other issues. Therefore, on the basis of the existing wet dedusting technology, this paper proposes to adopt multi-level counter-spray method to solve the problems of low efficiency, high water consumption and high energy consumption in traditional wet dust removal, and so on. It is of great significance for the research of dust removal technology. In the past, most of the researches on spray dust removal were concerned about the total dust removal efficiency, but ignored the influence of atomization particle size change caused by the change of spray pressure on the dust removal efficiency. Therefore, on the basis of the traditional spray dust removal mechanism, the atomization particle size of the nozzle is measured by image measurement technology. The results show that the total trend of atomization particle size change is as follows: with the increase of spray pressure, The average atomization particle size decreased gradually. When the spray pressure increased from 0.2MPa to 0.4MPa, the average atomization particle size changed greatly, from 456 渭 m to 219 渭 m, showing an approximate linear relationship. When the pressure changes in 0.5~0.6MPa, the average atomization particle size changes steadily, from 176 渭 m to 165 渭 m. When the spray pressure increased from 0.1MPa to 0.8MPa, the average flow rate of the corresponding washing water increased from 0.6L/min to 2.1 L 路min, and the results of repeated tests showed that the spray pressure increased from 0.6L/min to 2.1L 路min, and the average flow rate of corresponding washing water increased from 0.6L/min to 2.1L 路min. The rising curve shows a linear trend. According to the experimental results of spray particle size experiment, the volume ratio of liquid to gas and the average velocity of gas in multi-level spray washing tower were studied by using air, water and dust particles as medium. The influence of dust concentration, spray pressure and other parameters on dust removal efficiency. The results show that the number of spray layers in the scrubbing tower has the most significant effect on the dust removal efficiency. Compared with the traditional single layer, the dust removal efficiency can be increased by more than 15%. Under the experimental conditions, the change of the inlet dust concentration has little effect on the dust removal efficiency, increasing the spray pressure can effectively improve the dust removal efficiency, when the spray pressure is 0.5~0.6MPa, the change of the dust removal efficiency tends to be stable. Under the same operating parameters, properly reducing the average velocity of gas in the column is beneficial to improve the dust removal efficiency of the scrubbing tower. For the three-layer spray washing, the optimum average flow rate in the gas column is 0.6 脳 0.8 mm2 路m ~ (- 1) 路m ~ (- 1); When the spray pressure is 0.6 MPA, the average gas velocity in the tower is 0.6 m / s, the volume ratio of liquid to gas is 5.27, and the inlet dust concentration is 16g/m3, the dust removal efficiency of the three layers can reach 98.3%.
【学位授予单位】：东北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X701

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