The electro-spraying characteristics of ethanol for application in a small-scale combustor under combined electric field

Abstract A small-scale combustor with electro-spraying technique was investigated. It consisted of vertical quartz glass tubes with an inner diameter of 16.0 mm. A stainless steel ring and a stainless steel mesh were used as an extractor and a collector, respectively. A capillary tube with an inner diameter of 0.9 mm was used as a nozzle. The nozzle and the steel ring were connected to the positive electrode of Direct Current power sources. The steel mesh was the droplets collector and a flame holder. Stable combustion flame was observed under combined electric fields. The electro-spraying modes of pulsed-jet, cone-jet, skewed cone-jet, and multi-jet were observed. The operating ranges were divided into several regions at various voltages and flow rates. The whole fluid field was divided into the jet region and spraying region. The driving force in the jet region came from the electrostatic induction field between the nozzle and the steel ring. The electric field between the steel ring and steel mesh supplied the driving force to move liquid droplets in the spraying region. The steel mesh is a key component for the directional movement of liquid droplets. Taylor angles measured at cone-jet mode were in the range of 75.18°–82.45°.

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