Numerical Simulation Of Air Distribution Mode And Optimization On Biological Safety Cabinets

As the first layer of isolation, with the protection on human, product and environment, Biological Safety Cabinets play an important role in biological safety laboratory. As the fast development of biologic technology, medical treatment and hygiene, more and more biological safety laboratories and Biological Safety Cabinets have been put into use in the area of virus research, biological technology development and gene project. So the requirement of biological safety is much stricter. The study on Biological Safety Cabinets must be based on the deep understanding of the development, performance principle, criterion and performance requirements. Besides that, the problems that proposed by the experts must be taken into consideration.According to the measurement in Ruiyang Company, CFD is used in this paper to study the air distribution in the BSC, and the optimization is also based on the measurement data and CFD. Besides that, CFD is used to optimized a proper airflow outlet way for BSC Class III.The study results indicate that the down flow velocity range in YY0569 and NSF/ANSI 49-2002e should be modified, and after numerical simulation this velocity range should be modified to 0.25~0.405m/s. In the BSC there are two air split lines after the down flow air has passed through the HEPA, the form of air split line is only influenced by the negative pressure in the grilles, the down flow air and the inflow air. Through numerical simulation, it is proved that when the down flow air velocity and the inflow velocity change 0.05m/s, there is no leak of down flow and no perforation of inflow, as a result of this, numerical simulation can be used instead of microbe method. Online measurement shows that the air mode is influenced when there is human walking after the worker during performance and when the worker's arm is put in and out quickly, and universal probe is more accurate than single-direction probe. Through numerical simulation both at-rest and operational, the perforated panel is more suitable than grille panel to be the outlet way for BSC Class III.