Abstract: A burner assembly that produces very low NOx emissions includes a plurality of furnace gas openings for receiving a portion of furnace gasses back into a combustion cylinder. The burner assembly includes the combustion cylinder, a plurality of combustion air inlet conduits that extend into the cylinder and a plurality of fuel gas discharge nozzles that also extend into the cylinder. The burner assembly is mounted within a combustion chamber of a furnace, wherein the walls of the combustion chamber are provided with or are made up of heat transfer pipes.

Abstract: A method and apparatus for preheating a furnace during a warm-up phase of furnace operation. The furnace has main burners with a tubular fuel supply surrounded by a main combustion air duct defining an annular space between the supply and the duct that extends in an axial direction of the main burner. A pilot nozzle in the annular space extends in an axial direction of the burner towards an interior of the furnace and discharges readily ignitable fluid fuel jets through orifices in the nozzle toward the interior of the furnace. Combustion air from the duct is directed past the nozzle and is mixed with the fuel discharged from the orifices to form an ignitable mixture that is ignited to form the furnace heating pilot flame downstream of the nozzle.

Abstract: A burner assembly that produces very low NOx emissions includes a plurality of furnace gas openings for receiving a portion of furnace gasses back into a combustion cylinder. The burner assembly includes the combustion cylinder, a plurality of combustion air inlet conduits that extend into the cylinder and a plurality of fuel gas discharge nozzles that also extend into the cylinder. The burner assembly is mounted within a combustion chamber of a furnace, wherein the walls of the combustion chamber are provided with or are made up of heat transfer pipes.

Abstract: A burner for installation in a furnace having a combustion chamber defined by at least a furnace front wall, two side walls, a top wall and a bottom wall as well as heat transfer pipes through which a heat transfer medium flows and which are arranged on at least one of the top, bottom and side walls. A burner assembly is mounted to the furnace front wall and has a tubular member with an open distal end that is located inside the combustion chamber. The other end of the tubular member is attached to the furnace front wall. Several combustion air ports extend into the tubular member from the other, proximal end thereof and are coupled to a source of combustion air. Several fuel gas discharge nozzles also extend into the tubular member from the other end thereof and are coupled to a fuel source.

Abstract: A burner assembly that produces very low NOx emissions includes a plurality of furnace gas openings for receiving a portion of furnace gasses back into a combustion cylinder. The burner assembly includes the combustion cylinder, a plurality of combustion air inlet conduits that extend into the cylinder and a plurality of fuel gas discharge nozzles that also extend into the cylinder. The burner assembly is mounted within a combustion chamber of a furnace, wherein the walls of the combustion chamber are provided with or are made up of heat transfer pipes.

Abstract: Embodiments of the present invention are directed to a low NOx duct burner or heater for efficiently heating turbine exhaust gases (TEG) in a less polluting manner. In one embodiment, a heater for heating a gaseous stream flowing in a downstream direction through a duct comprises a heating gas supply pipe extending at least partially across the duct. The heating gas supply pipe includes a plurality of spaced-apart gas pipe outlets to discharge a portion of a heating gas into the duct generally in the downstream direction. A flame shield extends from a location at or near the heating gas supply pipe at least partially across the duct. A plurality of gas supply spuds are disposed upstream of the flame shield. The gas supply spuds include a plurality of gas spud outlets to discharge another portion of the heating gas into the duct.

Abstract: Heat is extracted from an oxidizable component in an anode gas generated by a fuel cell. A heat exchanger is in fluid communication with the fuel cell, and the anode gas flows through a first portion of the heat exchanger. The heat exchanger is further in fluid communication with a source of an oxygen-containing gas, such as air, and has a second portion through which the air flows, so that the temperatures of the anode gas and the oxygen-containing gas tend to equalize in the heat exchanger. A downstream end of the heat exchanger is in fluid communication with a space where the anode gas and the air mix and form a mixture of anode gas and air. A first burner located upstream of the heat exchanger heats the air. A catalytic oxidizer is in fluid communication with the space and oxidizes the mixture. The catalytic oxidizer emits a heated effluent that is directed back to the fuel cell. A second burner heats the effluent during at least portions of the time during the operation.

Abstract: A heater for heating turbine exhaust gas (TEG) flowing in a downstream direction through a duct formed by sets of opposing side walls is described. A flame shield has first and second plates which extend symmetrically with respect to a horizontal center line substantially across the duct, diverge in the downstream direction, and terminate in plate edges which are spaced from proximate duct side walls. Each plate defines spaced-apart, first and second slits which communicate an upstream side of the plate with a downstream side thereof. The slits are spaced from the center line and from the plate edges. A heating gas supply pipe extends parallel to the center line across the duct and has a plurality of spaced-apart orifices that face in a downstream direction and are in flow communication with the downstream side of the plate.

Abstract: A low NO.sub.x burner includes a refractory lined plate with a refractory side facing a combustion chamber. A multiplicity of combustion air passages extend through the plate toward the combustion chamber. A multiplicity of spaced-apart primary fuel nozzles each have a discharge opening being surrounded by one of the combustion air passages for directing fuel therethrough to mix with combustion air passing through the air passages. A multiplicity of anchor fuel nozzles project through the plate for directing fuel into the combustion chamber. The anchor fuel nozzles are spaced apart from each other and from the combustion air passages. The flows of fuel and combustion air through the primary and anchor nozzles and the air passages into the combustion chamber are controlled to generate a flame. In applications that require low excess air, such as boiler applications, the burner is modified by providing a secondary fuel and flue gas injection assembly to form a two-stage burner.

Abstract: An industrial fuel gas burner fired with a mixture of combustion air having up to about 45% flue gas which flows in a downstream direction along an annular combustion air conduit disposed about an axially movable core of the burner that terminates in an end cone that faces the combustion chamber of the furnace. Within the conduit and upstream of a discharge end thereof is a fuel gas discharge header formed by concentric, radially inner and outer tubular ring-shaped fuel gas headers which are concentrically disposed about an axis of the burner and in fluid communication with a source of pressurized fuel gas. The headers have a multiplicity of fuel gas discharge orifices which form three-dimensionally oriented gas streams directed into the combustion air-flue gas flow in the annular conduit. The orifices have a diameter of at least about 0.1 inch.

Abstract: A low NO.sub.x burner includes a primary air and fuel discharge assembly which, in turn, includes a burner plate having a plurality of slots from which fuel gas jets and combustion air are discharged. The slots are arranged such that the width of the recirculation zones between adjacent slots substantially varies between the central region of the burner plate and its perimeter. With this construction, the local ignition patterns vary such that local oscillations of flame front occur at different frequencies so that vibrations are greatly dampened and resonance problems in the furnace minimized or eliminated. In applications where high excess air is not desirable, such as boiler applications, the burner is modified by providing a secondary fuel and flue gas injection assembly to form a two stage burner. In the preferred embodiment, the secondary injection assembly includes a plurality of discrete fuel and flue gas injection tubes arranged around the primary air and fuel gas discharge assembly.

Abstract: A low NO.sub.x burner includes a burner plate having a plurality of slots from which fuel gas jets and combustion air are discharged. A plurality of fuel tubes are aligned with the slots for discharging the fuel gas therethrough. The fuel tubes are spaced from the slots so that combustion air, provided by a wind box, also can flow through the slots. The fuel gas and combustion air are discharged at high velocity, thereby generating very high turbulence in the combustion chamber downstream from the burner. The slots are arranged such that the width of the recirculation zones between adjacent slots substantially varies between the central region of the burner plate and its perimeter. With this construction, the local ignition patterns vary such that local oscillations of flame front occur at different frequencies and are not synchronized so that vibrations are greatly dampened and resonance problems in the furnace minimized or eliminated.

Abstract: A cooling system including a cooling duct adjacent to the hot air duct of an air heater. The cooling duct includes a first wall and a second wall spaced from the first wall such that a passageway is formed therebetween. A wire mesh sheet is arranged in the duct passageway. The wire mesh sheet comprises a plurality of layers of wire mesh and has an undulate configuration which together with its density prevents substantial heat radiation from the first wall of the cooling duct to the second wall without significantly impeding airflow through the cooling duct. Cooling air introduced into the cooling duct flows through the duct, removes heat, radiated by the first wall and absorbed by the wire mesh sheet, and carries that heat away from the duct as it exits through the outlet opening. In this way, the system cools the first wall and prevents any significant heat transfer to the second wall of the cooling duct and elements in the vicinity thereof.

Abstract: A burner suitable for use in conjunction with an air heater. The burner has a burner plate including a plurality of slots. The burner plate slots are aligned with and spaced from fuel supply tubes. The tubes have spaced apart orifices that discharge fuel gas in conical patterns and direct the gas jets through the slots in the burner plate and into the combustion chamber downstream from the burner. A baffle plate is positioned above the fuel supply tubes and extends across an air supply plenum. The baffle plate includes air discharge orifices through which the air from the plenum enters the burner in substantially uniform flow. The baffle plate orifices direct the air toward the burner plate for cooling. The air heated by the burner plate eventually flows toward and through the burner plate slots where it forms a layer between the fuel gas jets and the perimetrical surfaces and edges of the burner plate slots and, thus, maintains the fuel gas spaced from these surfaces and edges.

Abstract: An air flow stabilizer having a pleated baffle system for attenuating turbulence and correcting non-uniform velocity distribution of gaseous flow through a flow conduit. The stabilizer is constructed from a plurality of baffle segments connected together in an accordion-like configuration edge to edge and angularly to one another. Each baffle segment has apertures to facilitate flow-through of gaseous flow parallel to and laterally across the axis of the flow stream. The baffle segments are secured to the flow conduit with support combs at the upstream end and the downstream end of the pleated baffle and reinforced by lateral stabilizing supports to provide a rigid structure.

Abstract: A constant energy, constant spark rate ignitor system suitable for use in high energy ignition systems. The ignitor system includes a vacuum interrupter switch through which an energy storage capacitor discharges to fire a surface gap spark plug. Discharge of the energy storage capacitor through the vacuum interrupter can only occur upon actuation of the switch. The quantity of energy stored in the energy storage capacitor and the timing of capacitor discharge is therefore not a function of ambient operating conditions or the dielectric properties of the switch and can therefore be independently controlled. A voltage comparator and spark rate clock are used to trigger closure of the vacuum interrupter switch and fire the plug when the capacitor contains the desired quantity of energy and a clock signal is present. A current proving circuit is also provided to verify that current passes through the spark plug.

Abstract: A flame scanning system for monitoring a combustion process by detecting flame emission characteristics in the ultraviolet light spectrum. A metered relative flame intensity signal, flame-off signal, and flame-on signal are provided. A self-diagnostic feature produces a flame marginal signal indicative of substandard flame operation; a tube marginal signal indicative of imminent UV tube failure is also produced. A scanner shutter mechanism includes a check failure feature for detecting UV tube failure. An electronic assisted sighting indicator is also included to assist during on-sight scanner positioning and to provide optimum scanner placement.

Abstract: A burner for placement in an airstream that flows in a downstream direction comprising a gas pipe having fuel ports for admitting fuel gas into the airstream, a flame retainer for preventing a flame originating at the manifold from lifting off the fuel ports and moving down the airstream, and a flame shield extending from opposite sides of the gas pipe and away from the gas jet for shielding the flame base from the airstream. The flame shield has a baffle assembly disposed on opposite sides of the gas pipe for forming an air passage for directing a portion of the airstream to flow along the downstream surfaces of the flame shield and flame retainer. In one embodiment of the burner, the baffle assembly directs a first portion of the airstream to flow along the downstream surface of the flame shield toward the flame retainer and directs a second portion of the airstream to flow along the downstream surface of the flame shield and away from the flame retainer.

Abstract: A burner especially adapted for use with pulverized fuel slurries, such as pulverized coal-water slurries. The burner has an atomizing nozzle which disperses the slurry in the form of multiple, diverging spray cones issuing from a corresponding number of atomizing orifices. Each orifice is formed by a central atomizing air flow. The slurry is brought into contact with the air flow and is atomized thereby. Before the atomized air flow is discharged, it is enveloped by a rotating auxiliary air flow and constricted to generate a venturi effect which facilitates the formation of the diverging, cone-shaped discharge pattern. A combustion air spinner surrounds the nozzle and is constructed of multiple vanes which have circularly arcuate shapes and a length, in the direction of the air flow, which is least proximate the nozzle and greatest at the periphery of the vanes. This assures an even combustion air flow rate over the entire radial extent of the spinner.

Abstract: A burner especially adapted for use with pulverized fuel slurries, such as pulverized coal-water slurries. The burner has an atomizing nozzle which disperses the slurry in the form of multiple, diverging spray cones issuing from a corresponding number of atomizing orifices. Each orifice is formed by a central atomizing air flow. The slurry is brought into contact with the air flow and is atomized thereby. Before the atomized air flow is discharged, it is enveloped by a rotating auxiliary air flow and constricted to generate a venturi effect which facilitates the formation of the diverging, cone-shaped discharge pattern. A combustion air spinner surrounds the nozzle and is constructed of multiple vanes which have circularly arcuate shapes and a length, in the direction of the air flow, which is least proximate the nozzle and greatest at the periphery of the vanes. This assures an even combustion air flow rate over the entire radial extent of the spinner.