高效过滤器现场试验荧光素钠法中采样滤膜的性能研究

Performance study on sampling filters for sodium fluorescein method of HEPA filter field test

根据荧光素钠法的采样要求,建立了以荧光素钠为气溶胶介质的采样滤膜性能测试装置和方法,实测了7种玻璃纤维滤膜的阻力、本底荧光值及流速0.92~2.75 m/s下的过滤效率,并分析了各种滤膜性能对过滤器净化系数检测结果的影响。结果显示,滤膜本身过滤效率对高效过滤器系统净化系数的影响较小,其中的CF-A、FP5211、GC90滤膜的相对误差分别为0.014%、0.063%、0.082%;浸泡液浓度较低时,本底荧光值对系统净化系数的影响比较明显;而阻力过大限制了滤膜上荧光素钠的收集量,进而相对增加了本底荧光值的干扰。研究结果可以为采样滤膜的评价、选择、使用提供指导。

By the sampling requirement of sodium fluorescein method,a sampling filter performancetesting device was established using sodium fluorescein as aerosol agent. Seven glass fiber filter ’s resistance,background fluorescence and filtration efficiency of sampling flow rates from 0. 92 to 2. 75 m /s were measured,and then filter performance’s influence on the purification factor was analyzed. Results show that the filtration efficiency of filter membrane has little effects on the purification factor of HEPA filter for the tested relative error of CF- A,FP5211 and GC90 are as low as 0. 014%,0. 063% and0. 082% respectively. Mean while,effects of background fluorescence on system purification factor is obvious when the concentration of soaking solution is low; if the resistance were too large to limit collection of sodium fluorescein,it could increase interference of background fluorescence values. This study can provide guidance for evaluation,selection and usage of sampling filter.