다중노즐을 이용한 정전분무 특성 연구

Abstract

An experimental investigation was performed on multi-nozzle electrospray that was operated in the cone-jet mode. The effects of liquid flow rate, applied voltage to the guard plate, and electrospray geometry on droplet size, droplet velocity, and spray angle were systematically investigated. Operating the electrospray in the cone-jet mode, charged micro droplets can be obtained in almost uniform size. Thus the cone-jet mode electrospray has been applied to some interesting fields such as medical powder production, film coating process, electrostatic painting, etc. We designed an electrospray system with multi-nozzle for overcoming low flow rate of electrospray in the cone-jet mode. At the standard condition, the cone-jet mode is generated by supplying ethanol at a various liquid flow rate (5~40 μL/min) through the syringe pump and applying a high voltage (0~5 kV) to a stainless-steel capillary tip (0.5 mm i.d., 0.9 mm o.d.). There were no differences in the generated droplet size distribution between the single- and multi-nozzle electrospray with a guard plate which made the spray angle became smaller. The droplet velocity increased with the increase of voltage applied to the guard plate.