Self-cooled oxygen-fuel burner for use in high-temperature and high-particulate furnaces

A burner apparatus comprising:

• a) a burner block having a fuel conduit, the fuel conduit having an inlet and an outlet, the outlet of the fuel conduit opening into a substantially conical oxidant expansion chamber;
• b) the burner block further having a substantially annular oxidant passage, the fuel conduit positioned within the substantially annular oxidant passage;
• c) the substantially annular oxidant passage having an inlet end proximate the fuel inlet and an outlet proximate the fuel conduit outlet, and having positioned therein at least one swirler for creating a swirling oxidant flow;
• d) the substantially annular oxidant passage fluidly communicating at its outlet end with the substantially conical oxidant expansion chamber in the burner block, the substantially conical oxidant expansion chamber having an inlet diameter Ds and an outlet diameter Dc such that Dc is at least 110% of Ds;
• e) a substantially cylindrical combustion chamber having diameter Dc and having an inlet and an outlet, the outlet of the substantially conical oxidant expansion chamber positioned in fluid communication with the inlet of the substantially cylindrical combustion chamber, the outlet of the substantially cylindrical combustion chamber opening to a furnace chamber;
• f) the outlet of the fuel conduit being recessed a distance Lr from the substantially cylindrical combustion chamber outlet, where Lr=Lc+Le, where Lc=length in axial direction of the substantially cylindrical combustion chamber, and Le=length in axial direction of the substantially conical oxidant expansion chamber;
• and
• g) wherein Le is about 10% to about 50% of Lr.