Design of a gas extractor for minimizing the concentration of chemical aerosols in the automotive ironing and painting process

Abstract

In automotive body and paint shops, one of the main causes of exposure to chemical aerosols is poor ventilation and the lack of extraction systems, affecting workers' health. Therefore, this study will evaluate the concentration of chemical aerosols to which workers in an automotive workshop in the city of Arequipa are exposed, in order to design a localized extraction system that improves ventilation and occupational health and safety conditions. To this end, three environmental measurements were taken during the work shift, lasting one hour for each stage of the production process (normal conditions, paint mixing, and spray application), using a personal sampling pump and the NIOSH 0600 gravimetric method. Concentrations of 0.143 mg/m3, 2.36 mg/m3, and 6.19 mg/m3 were obtained, respectively, the latter exceeding the maximum permissible limit of 3 mg/m3 established in the D.S. No. 015-2005-SA for respirable particles, which demonstrates significant overexposure during the spray gun application stage. Finally, given that the maximum permissible limits for chemical aerosols to which workers are exposed are exceeded, the implementation of a 2 HP centrifugal fan, a Ø300 mm flexible duct, and a three-stage filtration system is proposed. This system captures and expels contaminated air to the outside through a metal chimney, aiming to significantly reduce the concentration of contaminants.