A new electrostatic precipitator for breath-borne aerosol: preliminary study and tests

Abstract:

The goal of this master thesis was to preliminary study, design and test a new electrostatic precipitator (ESP) for the capture of human breath-borne aerosol. This system needs to collect aerosolized bacteria/viruses in exhaled droplets, while being compatible with an open interface micro-fluidic system, in which an integrated bio-sensor will detect their presence. The final system may constitute an efficient point-of-care test for lower respiratory tract infection diagnoses. The number of exhaled droplets and the amount of pathogenic material being extremely low, the system needs to provide a high collection efficiency, while being compatible with the technologies used in a point-of-care test.In this work, a thorough study of the state-of-the-art in particle collection systems is presented, as well as theories needed for the conception of an ESP. Based on this knowledge, the main features and solutions were chosen and integrated in a conceptual design of a novel ESP. COMSOL simulations were performed to guide the design of the collection system. A specific simulation code was written to simulate the droplets motion inside a highly simplified ESPmodel. Thereafter, an experimental setup was build, and several configurations of ESP were tested. The efficiency of each configuration was assessed by quantifying the amount of dye, initially dissolved in the dispensed liquid, collected by the ESP. An impinger, placed at the setup outlet, is used to quantify the losses inside the system.Three configurations of ESP were tested, and their collection efficiency analyzed. The best experiment has shown a very promising net collection efficiency of 45%. Conclusions were drawn from the three systems. Even though the ESP system has not met all the specifications, this preliminary study was successful.Finally, guidelines for the creation of a more efficient ESP, and for tests with pathogenic material, could be proposed.