Burner for combusting gas with low NO.sub.x production

A low NO.sub.x burner for combusting fuel gas and air in an enclosure comprising:

• a burner block having an inlet end and an outlet end and a central opening therethrough between the ends, the burner block outlet end being in communication with an enclosure to be heated by burning fuel gas, and the block having a plurality of spaced apart recirculation gas passageways extending between said inlet and outlet ends, the gas passageways being at least generally paralleled to and spaced from said central opening and having an injection passageway communicating each gas recirculation passageway with said central opening;
• gas directors positioned within said central opening in said block in alignment with said injection passageways, each gas director means being oriented to support primary combustion and to cause mixing action of gas and air passing into said central opening;
• and
• a fuel gas jet positioned within each of said recirculation gas passageways for injecting fuel gas into said injection passageways to cause the injected gas to mix with recycled gas within said injection passageways to provide a fuel gas/recycled gas mixture that impinge upon said gas directors, recycled gas being drawn through said recirculation gas passageways for recirculation back through said injection passageways into said central opening for mixing with and cooling a fuel/air mixture therein to thereby reduce the production of oxides of nitrogen.