Abstract: A burner assemblage includes an elongated, round burner assembly having a central axis and including internal baffle structure. The baffle structure is arranged to cause concentric primary and secondary air flows to move in a direction generally parallel to said axis. The secondary air flow is generally annular in shape and the same is disposed in generally surrounding relationship relative to said primary air flow. The assemblage also includes a swirler structure for swirling the air primary and secondary air flowing through the central portions of the burner. The swirler structure includes a first swirler component located in a position for swirling the primary air flow. The first swirler component has an outer circumferential edge that extends around the axis of the burner in radially spaced relationship thereto. The swirler also includes a second generally annular swirler component located in a position for swirling the secondary air flow independently of the swirling of the primary air flow.

Abstract: A round burner capable of being operated with reduced CO and NOx emissions includes a venturi tube positioned to direct a flow of air through the burner and into a combustion zone in a combustion chamber through an entrance in a wall of the combustion chamber. The venturi tube has inlet and outlet ends and a throat. The outlet end of the venturi tube has a larger internal diameter than either the inlet end or the throat and the same is positioned adjacent the entrance to the combustion chamber. The inlet end of the venturi tube is also positioned further from the entrance than the outlet end of the venturi tube. The burner may include a duct system that includes an inlet disposed in fluid communication with the combustion zone and an outlet disposed in fluid communication with the venturi tube adjacent the throat thereof.

Abstract: A round burner capable of being operated with reduced CO and NOx emissions includes a venturi tube positioned to direct a flow of air through the burner and into a combustion zone in a combustion chamber through an entrance in a wall of the combustion chamber. The venturi tube has inlet and outlet ends and a throat. The outlet end of the venturi tube has a larger internal diameter than either the inlet end or the throat and the same is positioned adjacent the entrance to the combustion chamber. The inlet end of the venturi tube is also positioned further from the entrance than the outlet end of the venturi tube. The burner may include a duct system that includes an inlet disposed in fluid communication with the combustion zone and an outlet disposed in fluid communication with the venturi tube adjacent the throat thereof.