固态气溶胶吸湿生长对过滤器检测效率的影响

本文使用加湿串联差分迁移分析仪（HTDMA）系统，研究了荧光素钠气溶胶在不同相对湿度（RH）环境中粒径的变化规律及对现场过滤效率的影响，且与NaCl气溶胶进行了对比。研究结果表明，荧光素钠气溶胶无潮解点，其粒径随相对湿度的增大而增大；NaCl有明显的潮解点，在小于75%相对湿度时，其粒径基本不变。随相对湿度的增加，直径为100 nm的荧光素钠测得的效率逐渐降低，而直径为100 nm的NaCl测得的效率在75%相对湿度以下时基本保持不变，但在大于75%相对湿度环境中大幅下降。因此，从气溶胶吸湿性能的角度来说，作为现场检测用的固态气溶胶，若保证环境相对湿度小于75%，NaCl和荧光素钠均可用于过滤器现场检测，且前者性能优于后者，但当相对湿度大于75%时，NaCl气溶胶已不能用于现场检测用途。

Effect of Solid Aerosol Hygroscopic Growth on Filter Testing Efficiency

In this paper,a hygroscopic tandem differential mobility analyzer(HTDMA)system was used to study the mechanism involving the variation of particle size of sodium fluorescein aerosol under different relative humidities(RHs)and its influence on in-place filter efficiency,and then the result was compared with that of NaCl aerosol.The results indicate that no obvious abrupt deliquescence is observed in sodium fluorescein aerosol and the particle size of sodium fluorescein aerosol increases with RH.However,for NaCl aerosol,the obvious deliquescence point is determined and the particle size remains constant within the range of RH at 0％-75％.Meanwhile,for sodium fluorescein aerosol of diameter with 100 nm,the filter efficiency decreases with the increase of RH.For NaCl aerosol of diameter with 100 nm,the filter efficiency remains unchanged when RH is below 75％,but decreases dramatically when RH is over 75％.Therefore,from the view of aerosol hygroscopic growth,when RH is below 75％,both NaCl and sodium fluorescein aerosols can be used for in-place testing,and NaCl aerosol is more superior.When RH is over 75％,NaCl aerosol is not recommended to be used for in-place testing.