Electric arc confining device

Abstract

An arc chute for a high voltage load interrupter switch has a pair of closely spaced side walls defining an arc chamber. An inner side of each wall has at least one groove between an open outer end of the chamber and an inner area of the chamber where blade contact is first broken resulting in a electrical arc. The longer axes of the grooves are generally perpendicular to the direction of flow of expanding arc gases that form at an inner end of the chamber when the switch is opened under load. The grooves have a semi-teardrop shaped cross section with the deeper portions of the grooves nearer the outer end of the chamber. As the expanding arc gases flow toward the chamber opening, some gas flows into the grooves which function as vortex generators causing the gases to swirl. The swirling gases then reverse direction and impede the flow of additional gases coming from the inner end of the chamber, and increase the pressure within said chamber fostering arc interruption by aiding molecular recombination by reducing the distance between ions.