Method of heating a lightguide preform

摘要

This disclosure is directed to an oxy-hydrogen torch (10) comprised of a nozzle plate (16) captured between first and second outer members (12 and 14). Each outer member has a plenum (18) which open towards, and is separated by, the plate (16). The nozzle plate (16) has a plurality of spaced grooves (32-32) in one major surface (34) which are arranged in an interleaved relationship with the spaced grooves (36-36) on the opposite surface (38). The grooves (32 and 36) extend from an edge of the plate (16) to the respective plenums (18-18) in the outer members (12 and 14). Oxygen is directed into one plenum (18) and hydrogen urged into the other plenum. The gases pass through the respective grooves (32 and 36) to the surface (46) of the torch (10) for surface mixing and ignition.