【作者】 刘世超；

【导师】 刘俊杰；

【作者基本信息】 天津大学 ， 供热、供燃气、通风与空调工程， 2009， 硕士

【摘要】 今年由北美爆发的A/H1N1流感病毒(猪流感)呼吸性传染病席卷全球,造成了全球性的恐慌,严重威胁了人们的正常生活和健康。另外,随着生物安全实验室、医药、反恐以及传染病疫情控制需求的增加,使得纤维过滤器对微生物气溶胶的过滤理论和实验的研究日益迫切。本课题从经典的过滤理论入手,针对微生物在形状和动力学特性等方面的不同。对微生物粒径进行了修正,其修正粒径与微生物颗粒的形状因子有关。通过对经典的过滤模型进行了修正,得到了纤维滤料对微生物的过滤模型。应用修正的效率理论模型,从理论上分析了滤速对物理和微生物气溶胶过滤效率的影响。实验分析验证了Laskin和Collison两种发尘器发生邻苯二酸二辛酯(DOP)气溶胶和粘质沙雷(Serratia marcescens)气溶胶的粒径分布。实验结果显示,对于DOP气溶胶,在同等发尘条件下,Laskin的发尘量要大于Collison发尘量。而对于微生物气溶胶, Laskin的发尘量要小于Collison发尘量。实验结果显示,增加菌悬液浓度,其发生的微生物气溶胶浓度不一定增加。最后,通过搭建微生物过滤效率试验台,分别采用DOP和粘质沙雷气溶胶对修正的过滤理论进行验证,并就滤速对物理气溶胶和微生物气溶胶过滤效率的影响进行了实验研究。实验发现,无论是物理气溶胶还是微生物气溶胶,各个粒径通道的过滤效率均随测试滤速的增大而降低;相同风速下,高效过滤器对DOP气溶胶的过滤效率要低于微生物气溶胶。粒径为1μm时,滤料对微生物的过滤效率要高出1个数量级。课题对高效空气过滤器进行了扫描效率检测和20%风量检漏,结果发现,同物理气溶胶一样,过滤器对微生物气溶胶的扫描效率要低于其全效率。微生物气溶胶作为尘源时,20%风量检测可以鉴别出过滤器的漏点。另外,课题通过细针在过滤器上扎洞来模拟过滤器的漏点,并采用两种不同的气溶胶对过滤器局部效率进行了测试。实验发现,漏点处的局部效率降低很明显,这说明扫描检漏能够容易的检测出过滤器的渗漏点。渗漏处,过滤器对微生物气溶胶的过滤效率大于对物理气溶胶的效率。随着风速的越低,漏点处的局部效率越低,这种趋势正好与未渗漏处的趋势相反。更多还原

【Abstract】 Arising from North America, the outbreak of severe respiratory disease caused by A/H1NA virus brought the whole word into the abyss. The severe respiratory diseases are affecting people’s life and health significantly. Additionally, with the increasing demand of bio-laboratory, pharmaceuticals, antiterrorism and control of respiratory diseases, the research on filtration disinfection performance of HEPA filter is becoming more and more crucial.The study modified the traditional air filtration theoretical model(Kuwabara airflow) considering the difference of shape and aerodynamics characteristic of two types of aerosol, DOP and Serratia Marcescens. With the modified theory, the work performed the velocity’s influence on filtration efficiency.The work validated the sizes distribution of two types of aerosol from two different generators. The results showed Collison generated less DOP particles than Laskin in the same conditions, while the results were opposite for microorganism particles. Moreover, it seemed that Serratia Marcescens particles were not increasing with the concentration of Serratia Marcescens liquid.Additionally, with the DOP and Serratia Marcescens aerosol, the modified model was validated in the new filter scan test rig. The filtration efficiency of HEPA filter was conducted with the two different aerosols in different air velocity. The measurements showed the filtration velocity declined with the increase of air velocity for DOP and microorganism particles. With the same velocity, filtration efficiency of HEPA filter to DOP was less than that of Serratia Marcescens. Finally, the research conducted the scan filtration efficiency to Serratia Marcescens particles and leakage measurements with the 20% standard airflow. The results showed, as DOP aerosol, the scan filtration efficiency of HEPA filter to Serratia Marcescens aerosol was higher than total filtration efficiency. The measurement of 20% airflow could be used to detect the leakages of the HEPA filter. Moreover, the research measured the local efficiency of the HEPA filter with the two different aerosols. The results showed the local efficiency greatly decreased due to the leakage. The efficiency of the HEPA filter to bioaerosol is higher than that to physical aerosol. With the decrease of air velocity, the local efficiency displayed opposite trend as that without leakage.更多还原