It is common today to weld or cut metal by using an exothermic oxygen lance, which is a steel pipe filled with rods and having oxygen passing along the rods through the pipe to an ignited end of the pipe. In one method of igniting the pipe, one end of the pipe is heated by an acetylene torch or the like and then oxygen is supplied to the heated end until it begins to burn. Then the acetylene or other gas is shut off. Another method is to connect a 12 volt battery to the lance and strike an arc much like conventional arc welding. In a further method, piezeo-electricity creates an ignition spark, but this method uses an integrated system that requires specialized pipes and compatible holders therefor.
I have invented an oxygen lance igniter that not only obviates the need for acetylene or other gas, a 12 volt battery, or a specialized pipes to start exothermic lance operation. My igniter also permits easier, quicker lance ignition than existing methods. The igniter has an inner wall about the lance, the inner wall defining teeth to center the lance in the igniter and hold lances of differing diameters. The teeth also space the inner wall from the lance to form a flue between the inner wall, and the lance and this flue can receive oxygen during the lance ignition process. Concentrically surrounding the inner wall is an outer wall thicker than the inner wall. A flammable substance, typically a Thermit mixture, is between the inner and outer walls and is more rapidly combustible than the walls. A match head element at one end of the igniter initiates combustion of the flammable substance. A gap between the match head element and the lance allows oxygen from the lance to enter the flue to aid that combustion.