Application of Electrohydrodynamic Atomisation to Surface Disinfection

Abstract

The development of improved methods for surface disinfection has gained renewed interest during the first waves of the SARS-COV2 Pandemic when the need to assure massive disinfection of objects and spaces goes against that of reducing the consumption of chemicals and minimize the impact of disinfectants on exposed persons. Electrohydrodynamic atomization is considered a valuable option to improve disinfection efficiency, thanks to the benefits associated with the droplets charge. This paper presents preliminary experimental and model results on the application of an induction charging electrohydrodynamic atomisation process to the spraying of water solution of a conventional disinfectant under model conditions. In particular, electrospraying under simple jet mode with a whipping breakup has been tested. Experiments are aimed to characterize the droplet size distribution, the energy requirements and the spray coverage area over a target surface, while a simplified physical mathematical model is used to estimate the amount of disinfectant lost upon evaporation and the distribution of the droplets over the target surface. The electrospray is able to disperse droplets having a charge-to-mass ratio of around 1.67 mC/kg with an energy consumption of 23.4±7.8 J/L, being more efficient than other conventional hydraulic nozzles. These preliminary findings indicate a good matching between modelled and experimental data and suggest that electrospraying under simple jet mode with a whipping breakup can be a possible option for the spraying of disinfectants over surfaces.