Removing painting-generated VOCs in a commercial airplane hangar with multiple portable exhaust hoods

摘要

Ventilation is an important means of reducing the concentration of volatile organic compounds (VOCs) in airplane painting hangars. Currently both an upside-supply and floor-exhaust (UF) system and an upside-supply and downside-exhaust (UD) system are used. However, these two conventional systems have low ventilation efficiency. To improve the VOCs exhaust efficiency, this study proposed a novel upside-supply and multiple airexhaust (UM) system. The new system delivers conditioned air through ceiling inlets, as do the UF and UD systems, but it uses multiple portable exhaust hoods to extract VOCs. The VOC emission sources move with the painting locations; in response, the exhaust hoods should also be moved so that they are adjacent to the sources. The ventilation performance of the proposed UM system, and that of the UF and UD systems, was modelled with computational fluid dynamics (CFD). In addition, the UM system was measured on site after putting it into engineering application. The results revealed that the flow pattern of the UM system is similar to that of the pushpull ventilation, and the airborne pollutants are efficiently exhausted. Both the measured and simulated VOC concentrations in the occupied zone are significantly reduced as compared with the conventional UF and UD systems.