An experimental method to determine enzyme particle emission rate in workplace

The enzyme preparation industry has been developing rapidly in recent years whose products, such as food and detergents, benefit human life in many ways. However, enzyme particles emitted during feed-in processes at workplaces can impose great risks to the workers. Local exhausts are often used to improve the indoor air quality under such conditions. To design local exhausts efficiently, information about the movement and transport of enzyme particles in workplace is required. With Computational Fluid Dynamics (CFD), the workplace enzyme particle level can be predicted from given particle source emission factors. However, no research at present relates to the determination of this emission factor with respect to particle contaminant at micro-level. We used Elutriation Dust Column (EDC) experimental method to determine enzyme particle emission factors at workplace. The principle and operation of EDC were described in detail. By introducing the particle source emission factor obtained from EDC experiment into CFD calculation, enzyme concentration level was calculated for a workplace having one feed-in machine operated intermittently. Good agreements were observed between the calculated enzyme particle concentration distributions and onsite collected sample results. It concludes that EDC can be used to predict particle emission rate in the feed-in operation and may offer a way to predict enzyme particle emission rate in similar feed-in operation processes.