Abstract: In a low NOx burner, oil and gas are distributed into the combustion zone from within a central tube, surrounded by an outer tube to define an annular channel between the central tube and the outer tube. A windbox surrounds the inner and outer tubes to introduce air into the annular channel and through openings in the inner tube into the central tube. The central tube and outer tube are sized so that the velocity of air through the outer tube is substantially greater than the velocity of air flow through the inner tube to the combustion zone so that an axial recirculating air flow is generated in the combustion zone. The difference in the velocity of the air streams is maintained small enough so that minimum turbulence is generated in the combustion. The air flow paths are constructed so that no angular rotation in the air flow occurs in the combustion zone.