【作者】 郭佳佳；

【导师】 刘俊杰；

【作者基本信息】 天津大学 ， 供热、供燃气、通风及空调工程， 2012， 硕士

【摘要】 随着现代空调建筑的兴起,微生物气溶胶在空调建筑内引起的污染问题也更加重视。微生物气溶胶可以引起呼吸道感染和病态建筑综合症。微生物气溶胶的存在严重威胁着人类的居住环境和身体健康,对室内环境空气质量造成了影响。现在控制微生气溶胶污染的主要手段包括紫外消毒、化学涂料和空气过滤。空气过滤是一种既经济又安全的手段。过滤材料是空气过滤过程的重要部件。过滤材料主要有玻璃纤维和化学纤维两种。玻璃纤维在高效过滤材料中有着广泛的应用,而化学纤维能够加载静电,从而获得更高的过滤效率却不会引起阻力的增加。因此带静电的化学纤维也有着非常广泛的市场。到目前为止,对颗粒物气溶胶的过滤效率的研究已经非常成熟,但是对微生物气溶胶的研究还存在很多问题。究其原因在于研究人员使用的“标识”微生物气溶胶都不相同,微生物气溶胶和颗粒物在形状、密度其他特性等方面与颗粒物气溶胶存在着很大的不同。李全鹏和韩贵媛在微生物气溶胶空气过滤效率的研究做了大量的工作,他们研究了中效滤料的过滤效率以及容尘量等对微生物过滤的影响。此项研究是在上述研究的基础上进行的,研究高效滤料不同滤速下微生物气溶胶的过滤效率。结果表明亚高效和高效滤料对以粘质沙雷为代表的微生物气溶胶有很高的过滤效率,接近100%。因此在微生物要求不高的场合,采用亚高效滤料或者高效滤料已经可以达到要求。随着滤速的升高,高效滤料对微生物气溶胶的过滤效率虽然在减小,但是趋势不明显。而早在1930年静电力在过滤器中的实际应用就己经开始。但是静电过滤材料使用中会由于各种原因使荷电强度逐渐减弱,滤材上的电荷可能被中和,致使过滤性能下降。过滤性能的下降会导致控制的空气质量达不到标准。对于静电滤料而言,其去除静电后的效率就是“最低效率”。测量带静电过滤材料效率的方法大多采用欧盟标准EN779中推荐的测量方法,采用异丙醇浸泡方法对静电滤料进行消静电处理后再进行过滤效率测试。本实验在上述方法的基础上对三种带电滤料又进行了异丙醇熏蒸和蒸汽消静电处理,进行比对实验。分别测量了初始效率处理后4小时、8小时、24小时和48小时的过滤效率。结果发现熏蒸和蒸汽方法得到的效率趋势相同,静电滤料在最初的4小时内过滤效率下降得最快且基本达到稳定值。而采用浸泡方法的到的最低效率远高于其余两种方法得到的效率值。三种处理方法没有造成滤料的结构改变。更多还原

【Abstract】 With the development of the air conditioning, bioaerosol contaminant goes into people’s eyes. Bioaerosol can lead to the sick building symptom and respiratory infection. The existence of bioaerosol threatens people’s health and indoor air environment. Until now the methods of controlling bioaerosol are UV disinfection, chemical coating and filtration. Air filtration is the most economical and safe method of all. Filter medias are an important part of filtration process. Filtration media can be divided into glass fibers and chemical fibers. Fiber glass filter material has a wide range of applications in high efficiency air filters. And chemical filter material can be loaded with electrostatic, which leads to higher efficiency and lower resistance. So electrostatic filters are also widely used in markets.Filtration of indoor particulates has been studied extensively[1]. However, the experimental and theoretical study for indoor bioareosol is not comprehensive and systemic because people paid less attention to it before. Three are some reasons for this. The characterized bioaerosol is different from each other. And bioaerosol is different from particles in shape, density and other characters and so on. Senior students did lots of work in bioaerosol filtration. They studied the efficiency of medium efficiency filters and dust loading influence. Our study is based on the former work and studies the bioaerosol efficiency of high efficiency filters at different velocities. The results indicated that the efficiency of Serratia marcescens as the representative of the microbial aerosol on sub-high efficiency and high efficiency filters is very high, close to 100%. Therefore, in microbial less demanding situations, the use of sub-high efficiency or high efficiency filter can already meet the requirements. With the increase of filtration rate, high efficiency filter media for aerosol filtration efficiency of micro-organisms becomes smaller, but the trend is not obvious.As early as in 1930, the practical application of electrostatic in the filter had begun. However, charge strength of electrostatic filter material decreases owing to various reasons, the charge on the filter and may be discharged, resulting the reduce of filtration performance. Filtration performance degradation will lead to the air quality down to standard. For the electrostatic filters, the efficiency after the removal of static electricity is "minimum efficiency." The method of measuring the minimum efficiency with electrostatic filter material is recommended in the EU standard EN779, which is the use of isopropyl alcohol dipping method for anti-static treatment electrostatic filter and then tests the filtration efficiency. The experimental methods we used are fumigation and steaming treatment besides the dipping method. We make comparisons with the three experiments. We measured the filtration efficiency of processing in the initial 4 hours, 8 hours, 24 hours and 48 hours. The results showed that the efficiency obtained by fumigation and steaming shows a similar trend. In the first four hours, the filtration efficiency declines fastest and then keeps stable. The efficiency of dipping approach to the minimum efficiency is much higher than the other two methods, the efficiency. Above all, three kinds of treatment did not cause structural changes in the filter.更多还原