Preparation of charged droplets via electro-hydrodynamic spraying of polyelectrolyte solutions for the removal of floating particles with less than 10 um (PM10)

摘要

Ambient air quality tends to be worse due to the particle pollution in the region where the rapid commercialization is going on. Particulate matter (PM) describes fine inhalable particles with the specific diameter and smaller, and air quality monitors measure concentrations of PM throughout certain area. Generally, high-concentrated particles in atmosphere can be harmful to human health and fine particles, called PM2.5, are more dangerous because they can get into the deep parts of human organisms or even into the blood. Due to environmental concerns, various dust collection systems (cyclonic separators, filters, wet scrubbers, electrostatic precipitators) are applied for the degradation of fine particle concentration. These system have each pros and cons but they commonly need more energy or resource to maintaint the efficiency as the particles size become smaller. In this study, electro-hydrodynamic spraying process is applied in an air-flowing chamber system in order to generate very small charged liquid droplet which is used for the enhancement of particulate material aggregation on the surface of droplets. The spraying process is based on the phenomena that conductive liquids pushed through a thin capillary may form conically shaped menisci as a result of electrostatic forces and surface tension when an electrical field is applied. We investigate the formation of various size of charged droplets at optimal electric conditions by using the specific polyelectrolyte solution. Droplet formation phenomena at the single-tip nozzle are also monitored by high speed camera and the morphology of charged droplets is correlated with polyelectrolyte solution parameters such as surface tension, viscosity, conductivity.