Electrostatic Charge Measurements of Droplets of Various Liquids Falling over a Large Distance

In order to contribute to a better understanding of the electrostatic phenomena appearing during splash filling of liquids and to clarify the reasons why this process is suspected to increase static electrification especially due to atomization, accurate experiments of charge measurements were made on droplets of various liquids falling over a large distance (5 m). Eleven liquids of different conductivity and surface tension were tested. The results confirm that no charge evolution appears even over a long falling distance. A possible explanation of the static charge increase in splash filling is presented. Due to the generated electrostatic charges, the splash filling process poses some dangers. Here, the charge evolution of a single droplet is examined along its fall. From experiments with droplets of many different liquids, falling over 5 m, it is confirmed that the assumption that droplets are charged by friction with air, as still discussed in the explosion hazard community, does not hold true.