Numerical And Experimental Study On Indoor Particle Contamination In Enzyme Preparation Industrial Workplace

With the rapid development of bio-technology industry, bio-paricle contaminants become the focus of people's attention. Ventilation is an important way for particle elimination. The effectiveness of ventilation system determines indoor particle condition. Computational Fluid Dynamics (CFD), if reasonably applied, can help efficiently in industrial ventilation system upgrading for its costless. By coupling numerical analysis and experiments, a certain enzyme preparation workshop was taken as an example to investigate its contaminated condition and the effectiveness of the ventilation system.With detailed expatiation of turbulent flow and gas-particle calculation method, standard k-εmodel and lagrange particle calculation model were adopted with nonstructural method used for the discretization of gas-particle govering equations. As for the solve strategy, the grid methods, relaxation factors and boundary conditions, etc. were fully discussed.The transportation and distribution of particles are dependent on many factors, like the physical properties of particles, geometrical condition of the studied room and particle forces, which make every problem special. The experimentation, measurement and theoretical analysis were combined in this research to determine enzyme particle size, contaminant resource emission intensity and forces on the particles. It was found that mainly drag force and gravity exerted on 3.0-10.0μm particles in transportation. Mass balance analysis is not applicable for single resource emission intensity determination in spacious condition, while an elutriation dust column prosed here can work for this purpose in feed-in process. Additionally, with sufficient discussion on exposure mothod, transient calculation was applied here for risk level determination, which provides help for health protection and workshop contamination control.As a conclusion, Lagrange particle model, with high quality grid and sound numerical control, can be applicable in steady and transient calculation of capacious workshops for particle transportation and movement determination. Programs for Fluent DPM (Discrete Phase Model) calculation result make it possible to get discreted result, thus provide effective tools for detailed numerical analysis on local area condition. The pollution control methods,"source method"and"conflux method", are helpful in the control of contaminants of different properties in spacious condition.