Abstract: A fired heater unit is disclosed having at least one radiant heating section with each of the at least one radiant heating section having a heating element located therein. The unit includes a convection section operatively connected to the at least one radiant heating section, wherein the convection section having at least one vertically oriented convection tube. Each of the at least one convection tube being operatively connected to the at least one radiant heating section. Each of the at least one convection tube includes an inner tube having process fluid flowing therethrough, wherein the process fluid being heated by the at least one radiant heating section, and an outer tube extending along a predetermined portion of the inner tube, wherein the outer tube is spaced from the inner tube to form a flow path therebetween.

Abstract: A fired heater unit is disclosed having at least one radiant heating section with each of the at least one radiant heating section having a heating element located therein. The unit includes a convection section operatively connected to the at least one radiant heating section, wherein the convection section having at least one vertically oriented convection tube. Each of the at least one convection tube being operatively connected to the at least one radiant heating section. Each of the at least one convection tube includes an inner tube having process fluid flowing therethrough, wherein the process fluid being heated by the at least one radiant heating section, and an outer tube extending along a predetermined portion of the inner tube, wherein the outer tube is spaced from the inner tube to form a flow path therebetween.

Abstract: An improved process for heating furnaces using a burner design that produces very low level of undesirable nitrogen oxides is provided. The process recirculates a large volume of furnaces gases back to the burner where it is mixed with fuel gas in a plurality of recirculation ports prior to combusting with air in a primary combustion zone. Dispersion of the fuel gas in the recirculated furnace gases is believed to result in lower peak flame temperatures and therefore minimizing the formation of the pollutants, such as nitrogen oxides.

Abstract: In its simplest sense, the burner of the present invention includes a swirl chamber for creating a swirling flow path for primary combustion air. The burner also includes means communicating with the swirl chamber for introducing low heating value gas to the primary combustion air for discharge with the air into a flame zone. Also provided are means adjacent to each other for introducing secondary air and for introducing secondary low heating value gas positioned so that the secondary air and secondary low heating value gas intersect the flame zone, preferably above the region of the recirculating core of the flame and at such a point that the secondary air and low heating value gas have a minimal effect on the swirl aerodynamics of the flame.

Abstract: A staged air burner having a swirl chamber for providing a swirl flow path for primary combustion air, a tangential duct system for providing a tangential flow path for primary combustion air flowing toward the swirl flow path, and a converging passage structure for providing a converging flow path for secondary air which flows along the converging flow path inwardly toward an axis of the swirl chamber downstream of the latter. At least two fuel supply systems are respectively situated at two of the above flow paths for supplying combustible fuel thereto so that it is possible to fire fuel simultaneously at least at two of the flow paths.