A submerged combustion burner having co-axial fuel and oxidant tubes forming an annular space therebetween, wherein the outer tube extends beyond the end of the inner tube. A burner nozzle having an outside diameter corresponding to the inside diameter of the outer tube is connected to the outlet end of the inner tube and forms a centralized opening in fluid communication with the inner tube and at least one peripheral longitudinally oriented opening in fluid communication with the annular space. In accordance with one embodiment, a longitudinally adjustable rod is disposed within the inner tube for adjustment of fluid flow therethrough, and a cylindrical insert having at least one flame stabilizer for stabilizing a flame produced by the burner is attached to the outlet end of the outer tube. In accordance with another embodiment, fluid flow through the inner tube is achieved by a flow control valve operably connected to the inner tube.