Application of FLUENT in simulation of diffusion of airborne cyclohexanone in screen-printing process

Objective To understand the diffusion characteristics of airborne cyclohexanone from several pollution sources in the working area of screen-printing process, and then explore the control measures.

Methods The diffusion characteristics of airborne cyclohexanone from several pollution sources in the working area of screen-printing was simulated by FLUENT software. Based on the monitoring results and the calculation results, the spatial distribution characteristics of airborne cyclohexanone concentration in the working area of screen-printing process were discussed. The effects of installation location of ventilation, inlet wind speed, inlet area and obstacles on the diffusion of cyclohexanone were studied.

Results The monitoring data visually revealed that concentration of airborne cyclohexanone was higher near both the corners and the sources of pollution. The simulation results, according to different inlet wind speed, inlet areas and/or air supply forms, showed that:(1) while the inlet air velocity was 0.8 m/s, the airborne cyclohexanone in the workshop was lower than that while the inlet air velocity was 0.2 m/s, which indicated inlet air velocity was one of the key factors for the diffusion of airborne cyclohexanone; (2) enlargement of the inlet area would change both the airflow form and velocity in the workshop, resulting in the change of dilution of airborne cyclohexanone concentration, which indicated the inlet area was also one of the key factors for the diffusion of airborne cyclohexanone; (3) the airflow forms varied with different air supply forms, such as from left window or right window, and the airflow coming from the upper wind of the pollution source would benefit the emission of chemical hazards in the workshop along with the air flow through the exhaust hood installed above the screen-printing machine.

Conclusion Using FLUENT software to simulate the diffusion of airborne cyclohexanone in screen-printing process could visually reveal both distribution and accumulation pattern of chemical hazards in three-dimensional space. It would be conducive to the monitoring and prevention of occupational hazards.