This invention relates to means for heating air and gases and more especially to gas heaters of the tubular type in which the heat energy of gases of combustion (flue gases) is utilized for the heating up of other gases or air. It is an object of this invention to provide means whereby the...

Tubular gas heater

Method of recovering oil from oil shale

A burner assembly (10) for process heaters or the like comprising a burner block (14), primary gas jets (20), secondary gas jets (22), a flame holder (26), and an air register for installation in a furnace wall or furnace floor is described. The burners are characterized in that primary fuel is introduced into the primary combustion zone (24) of the burner at an angle horizontal to the flame holder whereby the fuel induces furnace gases from the furnace into the primary combustion zone. Similarly, the secondary fuel jets introduce a secondary fuel through the burner block for consumption in a combustion zone at the surface of the burner block. The secondary fuel also draws furnace gases into the combustion zone for consumption. The design provides for intense mixing of combustion air with the fuel and furnace gases, resulting in low NOx levels.

Low NOx burner assemblies

A burner for combusting gas and/or liquid fuel and air in an enclosure includes a burner block of non-combustible material, such as ceramic material, having a central opening therethrough communicating with a combustion zone. The burner block has a plurality of spaced apart recirculation gas passageways paralleled to and spaced from the central opening, each of the recirculation gas passageways having an injection passageway communicating with the block member central opening. Fuel, which may be liquid and/or gas, is injected into said burner block central opening. Venturi action causes furnace gas to be drawn from the cool fringes of the combustion zone through the recirculation gas passageways for passage back into the central opening wherein air and fuel are thoroughly mixed and cooled for combustion within the enclosure. This recirculation system serves to reduce the temperature and oxygen content of the local combustion process to thereby reduce NO x production. An annular flame director ring positioned within the burner block central opening adjacent to and below the injection passageways augments the Venturi action to increase flow through the recirculation passageways.

Burner for combusting gas and/or liquid fuel with low NOx production

A burner for combusting fuel gas and air in an enclosure includes a block member of non-combustible material, such as ceramic material, having a central opening therethrough. The block member has a plurality of spaced apart recirculation gas passageways paralleled to and spaced from the central opening, each of the recirculation gas passageways having an injection passageway communicating with the block member central opening. A fuel gas jet is positioned within each of the recirculation gas passageways for injecting fuel gas into the injection passageways to cause the injected fuel gas by Venturi action, to draw furnace gas from the cool fringes of the combustion zone through the recirculation gas passageways for passage back into the central opening after local combustion wherein modified air and fuel gas are thoroughly mixed and cooled for combustion within the enclosure. This recirculation system serves to reduce the temperature and oxygen content of the local combustion process to thereby reduce NOx production.

Tubular gas heater

Citations

Method of recovering oil from oil shale

Low NOx burner assemblies

Burner for combusting gas and/or liquid fuel with low NOx production

Burner for combusting gas with low NOx production

Heavy fuel burner with combustion gas recirculating means

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