Abstract: An improved collimator for a plasma arc torch consists of an annular holder member and an insert member. The insert member includes a tubular stem portion ending in an integrally formed, radially extending face plate. When the stem portion is fitted into the central bore of the holder member with a predetermined clearance fit therebetween, a cooling water passage is created. The improved collimator is characterized by the absence of any welds between the holder member and the insert member that would be exposed to conductive gases given off during use of the plasma arc torch and a lesser resistance to cooling water flow than prior art collimator designs.

Abstract: To protect the collimator of a transferred plasma arc torch from premature failure due to corrosion, an anti-corrosive covering is applied on the exposed face surface and a portion of the inner exit bore of the collimator. The specification describes several methods for producing the collimator for a plasma torch having an anti-corrosive coating or cladding on the exposed surfaces thereof, including electroplating, electroless plating, flame spraying, plasma spraying, plasma transferred arc, hot isostatic pressing and explosive cladding.

Abstract: A method for gasifying a wide variety of biomass into hydrogen and carbon monoxide (syngas) using plasma torch technology. Generally, biomass is converted into syngas by feeding biomass into a reaction chamber, directing the beam of a plasma torch across the face of the biomass in the chamber, and extracting hydrogen and carbon monoxide rich gas from the reaction chamber. The extracted gas can then be used as a gaseous fuel substitute for natural gas or as a feedstock for conversion to synthetic liquid fuels.