EXOTHERMIC REACTIONS AND METHODS

摘要

Exothermic reaction mixtures are electrically ignited with a low cost fo il strip of two conductive strips separated by a layer of insulation. One or mo re holes are formed in the ignitor to create shaped spark plasma on one side an d a venting plasma on the opposite side of the hole. The spark with low energy requirements is sufficient to ignite exothermic reactions for welding, casti ng and other uses. The ignitor may be part of reusable crucibles and molds, or expendable packages, containers, and molds, or smaller squibs for igniting larger charges. The ignitor may be immersed in or substantially adjacent the charge of exothermic material. The spark forming hole or holes is made and shaped by a punch in a simple and low cost manner. The ignitor eliminates the need for starting powders or materials and flint gun ignitors.