Preheated fuel and oxidant combustion burner

A burner apparatus comprising an upper refractory burner block and a lower refractory burner block, and further comprising:

• a) a conduit adapted to convey preheated oxidant and having outlet and inlet ends;
• b) a conduit adapted to convey preheated fuel and having outlet and inlet ends, the conduit adapted to convey preheated fuel being substantially parallel to the conduit adapted to convey preheated oxidant, the conduit adapted to convey preheated oxidant being positioned in the upper refractory burner block and substantially vertically above the conduit adapted to convey preheated fuel which is positioned in the lower refractory burner block;
• c) the conduit adapted to convey preheated oxidant positioned within its own elongate cavity in the upper refractory burner block and the conduit adapted to convey preheated fuel positioned within its own respective elongate cavity in the lower refractory burner block, each of said conduits positioned in their respective cavity such that a substantially annular region is present between an outer surface of each said conduit and its respective cavity;
• d) each conduit inlet end extending through a respective plenum for receiving an ambient temperature fluid, the plenums adapted to pass said ambient temperature fluid into the respective annular regions,
• e) with the provision that the conduit adapted to convey preheated fuel extends almost entirely the length of the refractory block to an expansion point which is machined into the refractory burner block lower section, and a passage adapted to flow at least a portion of said ambient oxidant there through is provided, the passage positioned to give a substantial tangential-axial momentum to the ambient oxidant to cause it to swirl in the ambient fuel cavity, causing delayed combustion of the ambient fuel and preheated fuel.