袋式除尘器除尘特性的实验与数值研究

发布时间：2018-02-02 09:18

本文关键词： 袋式除尘器运行阻力除尘效率湿式滤袋　出处：《山东大学》2017年硕士论文　论文类型：学位论文

【摘要】：近几年来,PM2.5等颗粒物污染日益严重,对人类的生存环境和身体健康构成了严重的威胁,所以提高除尘器的除尘效率势在必行。本文以袋式除尘器为主要研究对象,旨在为除尘器的优化发展提供一定的帮助与支持。本文分别通过实验研究与数值计算两种手段对传统式和旋转式两种结构下的袋式除尘器展开了研究。并通过对获得的运行阻力结果的比较确定了实验与数值模拟的统一性。文中结合湿式除尘技术提出了将袋式除尘器的干式滤袋改进为湿式滤袋的湿式除尘技术。理论分析认为,对滤袋加湿以后,可以降低滤袋的孔隙率,过滤时筛分效应增强,并减少了粉尘颗粒对滤料纤维孔隙的填充,促使过滤模式更早的过渡到表层过滤,可以有效提高除尘效率而且清灰更加方便。同时喷水加湿以后,粉尘颗粒表面的粘附力增大,细小颗粒物团聚成为大颗粒从而更容易被捕集。综上,采用湿式袋式除尘器可以有效地提高除尘器的除尘效率,但也会使运行阻力上升。所以本文主要对两种结构除尘器的运行阻力和对粉尘的捕集效率两种除尘特性进行了研究。对于传统式袋式除尘器,气流分布的均匀性是衡量袋式除尘器设计优劣的标准之一。文中通过数值计算对其内部的流场进行分析,得到气流的流动与分配规律,并根据评价气流均匀性的三个指标—对进行定量的评价。结果显示,各项指标均在允许范围之内,可以认为气流分布基本均匀。对于传统式除尘器共计研究了介于1.00m/min～3.00m/min之间的九种过滤风速下,分别采用干式与湿式滤袋时除尘系统的运行阻力和过滤效率变化规律。研究结果显示随着过滤风速增加,在干式与湿式滤袋状态下,运行阻力都在逐渐增加,而除尘效率呈现出先降低后升高的规律。采用湿式滤袋时,系统的运行阻力约变为干式滤袋时的3倍左右,除尘效率有明显的提高,增幅约在0.6%～0.8%之间,粉尘排放浓度降低至干式时的75%到82.9%之间不等。对于文中新提出的旋转式袋式除尘器,首先通过数值计算对两个结构参数比间距和充填比进行最优化设计计算,并最终选取比间距为20,充填比为14时的参数组合进行实验研究。实验中对介于0.3m/s～1.4m/s之间的8种迎面风速下,分别采用干式和湿式滤袋时除尘器的运行阻力和对粉尘的捕集效率进行研究。结果显示采用干式和湿式滤袋时系统的运行阻力和对粉尘的捕集效率都随着风速的增加而逐渐提高。采用湿式滤袋后,旋转式的运行阻力和除尘效率都有所增加,其中运行阻力约上升为干式滤袋的2.6～2.7倍,除尘效率的增幅约在0.4%～0.6%之间,除尘器出口排烟粉尘浓度降为干式的82.8%～91.8%之间不等。文中提出的湿式滤袋除尘技术可以有效地提高除尘器的除尘效率,大幅度降低排烟的粉尘浓度,但是阻力增幅较大,适用于作为除尘器的二级或者末级除尘设备,用于除去细小的粉尘颗粒,并避免过大的阻力和发生结露。对于本文中提出的旋转式袋式除尘器,其运行阻力低,但是也在一定程度上降低了除尘效率。所以旋转式袋式除尘器适用于对粉尘的性质和除尘效率要求不高的场合,也可以用作除尘器的初级除尘单元,或者通过适当的增加滤层数目在控制阻力的前提下提高除尘效率。本文的研究对湿式滤袋除尘技术和袋式除尘器的优化设计提供了参考,具有一定的理论研究和实际应用价值。
[Abstract]:In recent years, PM2.5 particulate pollution is becoming increasingly serious, constitutes a serious threat to human living environment and health, so it is imperative to improve the dust efficiency. This paper bag filter as the main research object, aims to provide some help and support for the optimization of development by precipitator. Experimental study and numerical calculation of two kinds of means of bag type dust collector of traditional and rotary two kinds of structures were studied. By comparing the results obtained by running resistance to determine the unity of experiment and numerical simulation. This paper proposed combined wet dedusting technology node will dry the filter bag of bag type dust collector improvement for wet dedusting technology of wet bag. According to the theoretical analysis, the bag bag can be reduced after humidification, porosity, filtering sieve effect enhancement, and reduce dust particles on the filter fiber Pore filling, the filtering mode earlier transition to surface filtration, can effectively improve the dedusting efficiency and cleaning more convenient. At the same time spray humidification after increasing the adhesion of dust particles, fine particles agglomeration become large particles and thus more easily captured. To sum up, the wet bag filter can effectively improve the the dust efficiency, but also make the running resistance increase. This paper mainly focuses on two kinds of running resistance and the dust collecting efficiency of two kinds of dust removal characteristics were studied. The traditional bag type dust collector, the airflow distribution uniformity is one of the standard measure of the quality of design of bag type dust collector for in this paper. Through numerical calculation of the internal flow field analysis, obtains the flow and distribution of airflow, and according to the three indexes to evaluate the airflow distribution of the quantitative evaluation. The results show that the indicators are within the allowable range, that air distribution is essentially uniform. For the traditional type dust collector were studied from 1.00m/min to nine kinds of filtration velocity between 3.00m/min, respectively by dry and wet bag when the dust removal system running resistance and filtration efficiency variation. Research results show that with the increase of filtration velocity. In the dry and wet bag under the condition of running resistance are increased, and the removal efficiency showed first decreased and then increased by wet bag law. When the system is running resistance of about 3 times the dry condition, the dust removal efficiency is obviously improved, an increase of about 0.6% ~ 0.8%, dust emission when the concentration is reduced to 75% to 82.9% dry range. For rotary bag type dust collector new is proposed in this paper, firstly, through numerical calculation of two structural parameters than distance and charge Fill ratio optimization design calculation, and finally select space ratio was 20, 14 for filling ratio parameters for the experimental study. In the experiment of 8 between 0.3m/s ~ 1.4m/s wind speed, using dry and wet bag and the dust collecting efficiency of the running resistance when the dust collector. The results show the running resistance by dry and wet bag system and dust collection efficiency with wind speed increased. The wet bag, rotary operation resistance and efficiency are increased, the running resistance increased to about 2.6 to 2.7 times of the dry bag, the dust removal efficiency increase about 0.4% ~ 0.6%, the dust outlet dust concentration is reduced to 82.8% ~ 91.8% range between the dry - wet bag filter techniques proposed in this paper can effectively improve the dust efficiency, large Reduce the dust concentration of the smoke, but the resistance is increased greatly, apply as precipitator two or final dedusting equipment, used to remove dust particles, and avoid excessive resistance and condensation. The rotary type bag filter in this paper, the low running resistance, but also reduces the dust efficiency in a certain extent. So the rotary bag type dust collector is suitable for the nature of the dust and the dust removal efficiency of less demanding occasions, primary dust removing unit can also be used as precipitator, or increase the number of filter layer to improve the efficiency in the premise of controlling resistance under proper. This study provides a reference for optimization design the wet bag filter technology and bag type dust collector, has certain theoretical and practical value.

【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X701.2

【相似文献】