CEM - Abstract

Abstract Information :

High temperature metallurgical processes use metals most of the time in powder form in the manufacturing process. However, it is well known that these generate fine particle production. The French regulation tend to enforce particle and gas emission reduction in the workplace and the environment. In spite of this requirement, the nature of these emissions is not well known yet. In this context, many stakeholders of this sector of which the members of this project (CaRPE) underline the necessity to master the effluent flow particles originating from the manufacturing processes. The main objective of this project was to focus on three processes (Thermal spraying, additive manufacturing, atomization) and to characterize the waste stream to better control it. Thus, different kind of emissions were broached in the project. Channeled emissions were characterized upstream and downstream the filtering system and filtration efficiency was assessed. Diffuse emissions were dealt with in the vicinity of the production processes. In the framework of the CaRPE project, several sites were selected to characterize different kind of emissions as indicated above. Three measurement campaigns resorting to a full panel of instruments dedicated to particle and gas detection were carried out on these sites. The results of this presentation are only focused on thermal spraying. Results evidence in some cases production of nanostructured particles. Despite a rather high filtering efficiency, some processes release nanoparticles with high number concentrations in the environment. Diffuse emissions were observed at different stages of the production. In conclusion, the improvement of the filtration system could help controlling release at stack emission. Good manufacturing practices could reduce diffuse emissions. In view of future developments, knowledge of the morphologies, sizes, and structures of the particles should help the manufacturer dimensioning the filtration systems and avoiding pollution. Work remains to be done to avoid as much as possible particle release to the environment and diffuse emissions.