Hu Shih-Cheng, Shiue Angus, Tu Jin-Xin, Liu Han-Yang, Chiu Rong-Ben
Department of Energy and Refrigerating Air-conditioning Engineering, National Taipei University of Technology, No. 1, Sec. 3, Chung Hsiao E Road, Taipei, 10608, Taiwan.
Air System Enterprise Co., LTD, Taipei, Taiwan.
Environ Sci Pollut Res Int. 2015 Dec;22(23):19264-72. doi: 10.1007/s11356-015-5091-5. Epub 2015 Aug 11.
For class II, type A2 biological safety cabinets (BSC), NSF/ANSI Standard 49 should be conformed in cabinet airflow velocity derivation, particle contamination, and aerodynamic flow properties. However, there exists a potential problem. It has been built that the cabinet air flow stabilize is influenced by the quantity of downflow of air and the height above the cabinet exhaust opening. Three air downflow quantities were compared as an operating apparatus was placed from 20 to 40 cm above the bench of the cabinet. The results show that the BSC air downflow velocity is a function of increased sampling height, displaying that containment is improvingly permitted over product protection as the sampling height decreases. This study investigated the concentration gradient of particles at various heights and downflow air quantity from the bench of the BSC. Experiment results indicate that performance near the bench was better than in the rest of the BSC. In terms of height, the best cleanliness was measured at a height of 10 cm over the bench; it reduced actually with add in height. The empirical curves accommodate, founded on the concentration gradient of particle created was elaborated for evaluating the particle concentration at different heights and downflow air quantity from the source of the bench of the BSC. The particle image velocimetry system applied for BSC airflow research to fix amount of airflow patterns and air distribution measurement and results of measurements show how obstructions can greatly influence the airflow and contaminant transportation in a BSC.
对于II类A2型生物安全柜(BSC),NSF/ANSI标准49应在柜体气流速度推导、颗粒污染和空气动力学流动特性方面得到遵守。然而,存在一个潜在问题。已经证实,柜体气流稳定性受向下气流的量以及柜体排气口上方高度的影响。当操作设备放置在柜体台面上方20至40厘米处时,比较了三种向下气流的量。结果表明,生物安全柜向下气流速度是采样高度增加的函数,表明随着采样高度降低,对产品的保护比对污染物的遏制越来越好。本研究调查了生物安全柜台面不同高度处的颗粒浓度梯度以及向下气流的量。实验结果表明,台面附近的性能优于生物安全柜的其他部分。就高度而言,在台面上方10厘米处测得的清洁度最佳;实际上随着高度增加而降低。基于所产生的颗粒浓度梯度建立了经验曲线,用于评估生物安全柜台面不同高度处的颗粒浓度以及向下气流的量。应用粒子图像测速系统对生物安全柜气流进行研究,以确定气流模式的数量和空气分布测量,测量结果显示了障碍物如何极大地影响生物安全柜内的气流和污染物传输。