Inhalation and deposition of gas-droplet contaminant in the human microenvironment in an industrial building

Gas-droplet contaminants such as HCl gas and hydrochloric droplets are typical pollutants in industrial indoor environments. They are harmful to workers. As the transportation modes of the gas and droplet phases are different, they cause different exposure characteristics for human beings. This study numerically investigated the transport of HCl gas and hydrochloric droplets emitted from a pickling tank to a human microenvironment. Meanwhile, inhalation and deposition of hydrochloric acid gas and hydrochloric acid droplets by humans were also studied, which were influenced by the droplet initial diameter (10-100 mu m), air draught (0.1-0.5 m/s) and the distance between the source and the manikin (0.5-1.5 m). The results showed that the cases considering an initial droplet diameter of 50 mu m could cause the largest droplet deposition on the manikin, which was influenced by the combination of droplet gravity and plume. The velocity of the air draught could significantly enhance the inhalation of HCl gas and droplet deposition on the manikin when the velocity was >= 0.3 m/s. Furthermore, when the distance was increased from 1.0 to 1.5 m, the thermal plume enhanced the inhalation of HCl gas.