Development of a high flow aerosol sampling device

Abstract: Small biological airborne particles (aerosols) reside in the atmosphere and can influence human health, the climate and the environment. Whereas aerosol sampling technology is well-known, there is currently no satisfactory high-volume flow impinger for health and atmospheric monitoring applications. The aim of this thesis was to design and construct a working prototype of an impinger, a sampling device that collects aerosols from high air flows. It was to be based on a prototype impinger taken from the water of an Kärcher DS 5.800 vacuum cleaner. The designing methodology used here was based on The Ulrich & Eppinger Generic Product Development Process. A 3D CAD-model of the water tank of the vacuum cleaner was created in Creo Parametrics, and thereafter imported in fluid simulation software (Autodesk CFD 2017) to predict fluid interactions inside the mixing chamber of the tank. Based on results from CFD analysis of the water tank and demands derived from interviews, specifications for the product were established and three main solutions concepts for the impinger were developed. Changes were made in an iterative process, and small adjustments were made in a CAD model for each concept, which were later simulated in CFD and evaluated. Two prototypes were developed. A 3D prototype was made to convey the visual design intention of the final product. A physical prototype was 3D printed and on which tests were performed to visually examine air and water mixing, water losses during operation and ergonomics. The developed impinger prototype worked as well as the simulations, had higher inlet efficiency than the original prototype impinger and was far more ergonomic. However, water losses remain high and this needs to be addressed in further work.