Abstract: A coaxial fuel and oxygen pipe apparatus can include a fuel pipe and an oxygen pipe, wherein the fuel pipe is contained within the oxygen pipe and the oxygen pipe comprises an internal diameter that is continuous without diameter changes along a length of the oxygen pipe. The fuel pipe can include an internal diameter that is continuous without diameter variations along a length of the fuel pipe. A discharge block includes a diverging section and a discharge that forms a final outlet with respect to the fuel pipe and the oxygen pipe. The discharge block is configured with two angles that can facilitate conditions for eliminating recirculation, wherein the two angles are matched to an expansion rate of the products of combustion to maintain a positive pressure throughout a final discharge from the final outlet.

Abstract: A coaxial fuel and oxygen pipe apparatus can include a fuel pipe and an oxygen pipe, wherein the fuel pipe is contained within the oxygen pipe and the oxygen pipe comprises an internal diameter that is continuous without diameter changes along a length of the oxygen pipe. The fuel pipe can include an internal diameter that is continuous without diameter variations along a length of the fuel pipe. A discharge block includes a diverging section and a discharge that forms a final outlet with respect to the fuel pipe and the oxygen pipe. The discharge block is configured with two angles that can facilitate conditions for eliminating recirculation, wherein the two angles are matched to an expansion rate of the products of combustion to maintain a positive pressure throughout a final discharge from the final outlet.