Formation of a charged droplets cloud and corona discharge between the cloud and a grounded electrode

In order to clarify the mechanism of a discharge occurring between a space charge cloud and a grounded object, the formation of a space charge cloud with highly charged droplets and the characteristics of the corona discharge occurring from a grounded electrode in the cloud have been investigated. The droplets sprayed from an airless nozzle were charged by induction charging and transported by additional air flow. A grounded electrode was inserted into the charged droplets cloud to cause a discharge in the cloud. The faster the velocity of the charged droplets transported by the air flow, the larger is the charge quantity of droplets. The magnitude of the corona discharge depends on the charge density of the cloud and the size of the grounded electrode. The maximum pulse height of the corona discharge was 50 mA in the negatively charged droplets cloud.