Abstract: A method of operating a combustion burner to heat a furnace. Fuel and combustion air are supplied into a combustion zone and ignited. Additional combustion air is supplied into the atmosphere outside of the combustion zone. The amount of additional combustion air supplied outside of the combustion zone is decreased as a temperature of the atmosphere inside the furnace increases such that the content of nitrogen oxides (NOx), as corrected for 3% O2 (cNOx (3% O2)), in the gases generated by combustion of the fuel and the combustion air and emitted from the furnace maintained below a predetermined value.

Abstract: A method and apparatus for heating a furnace using a burner system having first and second burner assemblies, each including a burner and a regenerative media bed, the method including operating the first burner assembly in a firing mode and the second burner assembly in a regeneration mode, switching the first burner assembly from the firing mode to the regeneration mode and the second burner assembly from the regeneration mode to the firing mode, and operating the second burner assembly in the firing mode and the first burner assembly in the regeneration mode. The burner assembly in the firing mode may be fired in either a first operating mode where the burner is supplied with preheated low calorific fuel and the burner is supplied with oxidizing gas or a second operating mode where the burner is supplied with preheated oxidizing gas and the burner is supplied with high calorific fuel.

Abstract: Regenerative burner for non-symmetrical combustion and a method of firing the burner. The burner includes a burner housing enclosing a burner plenum; a fuel conduit extending longitudinally within the housing and positioned coaxial with a line spaced from a central axis of the burner, with the fuel conduit defining a fuel exit opening; and a baffle positioned at least partially around the fuel conduit and defining an air conduit extending into the housing and defining an air opening on an opposite side of the burner central axis from the fuel exit opening. The baffle also defines a cavity adjacent the fuel exit opening and in communication with the fuel conduit through the fuel exit opening. The sidewall of the cavity converges from a central axis of the fuel conduit to provide further jet penetration into the furnace and achieve greater levels of products of combustion entrainment prior to combustion.

Abstract: A burner port block assembly having a refractory block with a central passageway therethrough and a ceramic extension piece disposed at least partially in the central passageway of the refractory block. The extension piece has a distal end, a proximal end, and a sidewall that defines a central passageway extending between the distal end and the proximal end. The central passageway of the refractory block is provided with a first engagement structure and the sidewall of the extension piece is provided with a second engagement structure. Engagement of the first engagement structure with the second engagement structure connects the extension piece to the refractory block. The burner port block assembly may further include at least one ceramic fiber board having a hole therethrough disposed at the distal end of the refractory block and/or a gasket positioned between the refractory block and the extension piece.

Abstract: A method of firing a melting furnace to which flux or fining additions are made, comprising supplying the burner systems with a fuel mixture containing at least 10% glycerin wherein the glycerin contains sodium chloride (NaCl), potassium chloride (KCl), or a combination thereof. The glycerin can advantageously be raw glycerin, a by-product of biodiesel production. It can be co-fired with natural gas or fuel oil or fired alone in traditional combustion burner systems. Alternatively, the glycerin may be supplied with NaCl and KCl in the same proportion as the flux used in the melting furnace. Significant fuel cost savings and potential flux cost savings may be realized using this method. The method is applicable to furnaces used in the production of aluminum or glass having similar burner systems and utilizing NaCl and/or KCl additions as part of the melting process.

Abstract: A refractory member for use in insulating a support beam or other heat-absorptive element in a high temperature furnace as well as a method of producing such members is provided. The refractory member includes a vacuum-formed refractory shape comprised of a fiber material and at least one binder, a reticulated, interconnected mesh embedded within the refractory shape, and an anchor element for securing the refractory member to the heat-absorptive element.

Abstract: A thermo-insulation article for a heat absorptive element, e.g., a water-cooled pipe, in a furnace has two parts joined to form a member for covering the pipe. Each part has an interconnected reticulated metal structure embedded in a refractory material. A thermo-insulating mat mounted over inner surface of the parts has a thermal conductivity lower, e.g., equal to or less than 25% lower, than thermal conductivity of the refractory material of the part. In one non-limiting embodiment of the invention, the thermo-insulating mat has a thermal conductivity equal to or less than 0.15 Btu's/hour/ft/degrees Fahrenheit, and the refractory material has a thermal conductivity in the range of 0.30-0.60 Btu's/hour/foot/degrees Fahrenheit. A surface of the mat is embedded in the refractory material and, optionally, a protective layer covers outer exposed surface of each of the mats to protect the mats during shipping and handling.

Abstract: An arrangement for protecting heat-absorptive elements in a high-temperature furnace includes a refractory member comprised of an interconnected metal structure embedded within the member and a tubular insert element capable of attaching the refractory member to the heat-absorptive element. The tubular insert has a hollow tubular body that is capable of sliding within a passageway through the embedded metal structure. The tubular insert has a rib or lip with an outer diameter larger than the passageway through the metal structure that engages the structure. When the other end of the tubular insert is connected to the heat-absorptive element, the rib holds the refractory member in place without a need to weld the tubular insert directly to the metal structure.

Abstract: An apparatus and method for using staged air combustion. The apparatus includes a burner body (10) secured to a port block (42), and a fuel passageway (12) extending through the burner body (10), terminating in a fuel nozzle (22), which injects fuel into the burner throat (40). Primary air jets (20) are configured to inject primary air into a primary combustion region (24), which is normally in the burner throat (40). A dish with a dish surface (28) is connected to the burner throat (40); the dish surface (28) extending in a divergent angle with respect to a burner centerline (35). Secondary air jets (34) are connected to the air passageway (14) and extend through the port block (42). The secondary air jets (34) inject secondary air into a secondary combustion region (38), which may be at the dish surface (28) or the hot face (30) of the burner.

Abstract: A burner for non-symmetrical combustion generally includes a burner housing enclosing a burner plenum. A fuel conduit extends within the housing and is positioned coaxial with a line spaced from a central axis of the burner. The fuel conduit defines a fuel exit opening. A baffle defining an air conduit extends longitudinally within the housing. The air conduit has an air opening on an opposite side of the burner central axis from the fuel exit opening. At least one oxygen injection lance extends longitudinally within the housing and partially through the air conduit. A burner port block is located adjacent to the baffle and downstream of the air opening, and is in fluid communication with the fuel conduit and the air conduit.

Abstract: A burner for non-symmetrical combustion includes a burner housing enclosing a burner plenum. A fuel conduit extends longitudinally within the housing and is positioned coaxial with a line spaced from a central axis of the burner. The fuel conduit defines a fuel exit opening. An air conduit extends into the housing and defines an air opening on an opposite side of the burner central axis from the fuel exit opening. The air opening is positioned a greater distance away from the burner central axis than the fuel exit opening. The air conduit has a cross-sectional shape in the form of a segment of a circle. A baffle is positioned at least partially around the fuel conduit and defines the air conduit. A burner port block is connected to the baffle downstream of the fuel exit opening. The burner port block has a sidewall diverging from the burner central axis.

Abstract: A radiant tube assembly comprises a radiant tube having a burner leg, an exhaust leg and a recuperator inside the exhaust leg and in a stream of products of combustion flowing in the exhaust leg. The recuperator has an air intake port at a first end and a mixing baffle at a second, hot end. The mixing baffle causes combustion air and products of combustion to be mixed at the hot end of the recuperator and provided to the burner leg for combustion. The mixing baffle includes a flow director which increases the amount of products of combustion mixed with the combustion air. The mixing baffle can also include a dome-shaped end which extends into the stream of products of combustion for reducing turbulence of the stream of products of combustion flowing in the exhaust leg.

Abstract: A radiant tube assembly includes a radiant tube having a burner leg with a burner therein, an exhaust leg and a connector leg. A recuperator is located inside the exhaust leg in a stream of products of combustion flowing through the exhaust leg. The recuperator has an air inlet port at the outer end and a mixing baffle at the inner end. The mixing baffle causes combustion air and products of combustion to be mixed at the inner end of the recuperator and the mixture is supplied to the burner for combustion.

Abstract: A regenerative burner having heat storage units with combustion effluent/combustion air ducts therethrough, fuel intake means and a burner body, wherein the burner is designed to suppress NOx formation and to control flame shape and characteristic in the regenerative system during combustion. The regenerative burner may include a burner baffle, or may include a plurality of gas jets entrained in generally converging fashion for control of the flame charactaristics and shape dispositive of NOx formation. The burner may provide for staged combustion, either by means of sequential fuel injection or sequential provision of combustion air, or the burner may depress NOx formation by vitiation of combustion air with products of combustion. The present regenerative burners suppress NOx formation yet preserve the remaining characteristic features of regenerative systems.

Abstract: A device for locking refractory insulation members on support elements in a heat treating furnace, boiler or other piping has a first strap end with a ramp and a second strap end with a raised bearing tab. The ramp engages the bearing tab with an interference-fit to capture the first strap end on the second strap end. The first embodiment of the invention includes a hook insertable in a window. The hook has a deflectable ramp with a bearing edge which engages a lock surface on the raised bearing tab to lock opposing strap ends to one another. The second embodiment of the invention includes an angled edge on the first strap end which engages the raised bearing tab on the second strap end. The first and second strap ends have opposing slots. The first strap end includes a notched back which, when the opposing slots are fully interengaged, receives the bearing tab to capture the first strap end on the second strap end.

Abstract: A regenerative burner having heat storage units with combustion effluent/combustion air ducts therethrough, fuel intake means and a burner body, wherein the burner is designed to suppress NOx formation and to control flame shape and characteristic in the regenerative system during combustion. The regenerative burner may include a burner baffle, or may include a plurality of gas jets entrained in generally converging fashion for control of the flame characteristics and shape dispositive of NOx formation. The burner may provide for staged combustion, either by means of sequential fuel injection or sequential provision of combustion air, or the burner may depress NOx formation by vitiation of combustion air with products of combustion. The present regenerative burners suppress NOx formation yet preserve the remaining characteristic features of regenerative systems.

Abstract: A method for providing uniform temperature in a furnace, such as a soaking pit or a reheat furnace is disclosed. Temperatures at a front wall and a burner wall within the heating chamber are constantly monitored by a computer, and the computer operates a direct-fired burner, or for example, a pair of regenerative burners, in one of two modes to place heat either at the front wall or the burner wall. The burner is oversized in relation to a maximum firing rate required by the heating chamber design. To heat the front wall, an impulse firing mode is initiated by the computer wherein the burner is fired at its full, overrated capacity for a time proportionally less than a normal firing cycle. To heat the burner wall, the computer initiates a proportional firing mode wherein the burner is fired for the full normal cycle, but at a rate which is equivalent to the actual firing rate demand calculated by the computer.

Abstract: A regenerative burner having heat storage units with combustion effluent/combustion air ducts therethrough, fuel intake means and a burner body, wherein the burner is designed to suppress NOx formation and to control flame shape and characteristic in the regenerative system during combustion. The regenerative burner may include a burner baffle, or may include a plurality of gas jets entrained in generally converging fashion for control of the flame characteristics and shape dispositive of NOx formation. The burner may provide for staged combustion, either by means of sequential fuel injection or sequential provision of combustion air, or the burner may depress NOx formation by vitiation of combustion air with products of combustion. The present regenerative burners suppress NOx formation yet preserve the remaining characteristic features of regenerative systems.

Abstract: A furnace for controlling flame temperature and emission of NOx comprising a burner to which fuel and air are supplied and product of combustion are discharged, wherein said air is vitiated with said products of combustion; a means for sensing furnace operating parameters including a flow rate sensor for sensing a flow rate of fuel to said burner and a first temperature sensor for sensing furnace temperature; and a means for controlling the amount of air vitiated with products of combustion, said controlling means in communication with said sensing means such that the amount of products of combustion vitiated with the air is controlled as a function of at least one of the rate of flow of fuel to said burner, the air temperature, and the furnace temperature, said control means is responsive throughout a firing range of said burner.

Abstract: A method and apparatus for repressing NOx formation in twinned regenerative burner pairs includes inducing a stream of hot flue gas, preferably containing enriched products of combustion, from the main hot flue gas exhaust stream and vitiating the preheated combustion air with the hot flue gas in the firing burner. An interconnecting duct communicating with the twinned burner pair includes a coaxial gas nozzle for injecting a high kinetic energy gas stream into the exhausting hot flue gas to induce a portion of the hot flue gas into the interconnecting duct to pass the hot flue gas to the firing burner for vitiation purposes.