Diffuse Electrical Discharges in the Absence of Flames

Abstract

KARLOVITZ^1,2 has proposed and investigated a device in which a high voltage electrical discharge is superimposed on a flame seeded with an alkali metal salt. The distinctive feature of this device is the spreading of the discharge through the flame volume. Usually discharges tend to contract as a result of feedback, causing an increase in the temperature of the discharge, which in turn causes a further increase in conductivity. Addition of an easily ionizable salt (in this case potassium carbonate) overcomes this instability by providing a better conducting path at lower temperatures and reducing the temperature coefficient of electrical conductivity. Because the discharge is dispersed through the flame volume higher voltages are possible than with an arc column and consequently currents used are comparatively small (5–15 A). Most of the subsequent work on such systems has concerned electrical properties and heat-transfer measurements^3–5.