Abstract: An apparatus for melting a metal load includes a furnace having a melting chamber with a hearth and a molten metal outlet. The apparatus further includes non-regenerative burners that are operative to fire into the melting chamber, and regenerative burners that also are operative to fire into the melting chamber. The method includes the steps of firing non-regenerative burners into the chamber to provide heat for melting the load, and also firing regenerative burners into the chamber to provide heat for melting the load.

Abstract: A burner has a port facing into a combustion chamber along an axis. A secondary fuel injector structure has secondary fuel injection ports that face into the combustion chamber at locations spaced radially outward from the burner port. A tertiary fuel injector structure has tertiary fuel injection ports that face into the combustion chamber in directions perpendicular to the axis at locations spaced axially downstream from the secondary fuel injection ports.

Abstract: A burner has a port facing into a combustion chamber along an axis. A secondary fuel injector structure has secondary fuel injection ports that face into the combustion chamber at locations spaced radially outward from the burner port. A tertiary fuel injector structure has tertiary fuel injection ports that face into the combustion chamber in directions perpendicular to the axis at locations spaced axially downstream from the secondary fuel injection ports.

Abstract: A vertical shaft melting furnace is operated in a method that includes firing a plurality of burners to generate combustion products, and directing jets of the combustion products into the shaft in a bottom region of the shaft. The method further includes directing a jet of hot gas into the shaft in an upper region of the shaft in a non-radial direction, whereby the jet of hot gas can induce a swirl to disperse a concentrated channel of combustion products rising from the bottom region to the upper region through a void in unmelted portions of a load of metal pieces in the shaft. The jet of hot gas directed into the upper region of the shaft can include recirculated flue gas, a mixture of air and recirculated flue gas, or combustion products that are generated by a burner. If the jet of hot gas includes combustion products that are generated by a burner, the burner is a secondary burner that preferably is fired into the shaft with a relatively low heat input.

Abstract: A method and apparatus provide combustion in a radiant tube in first, second and third stages, with flue gas recirculation that begins at the second stage.

Abstract: An apparatus includes a furnace structure defining a reaction zone. A burner structure communicates with the reaction zone through a burner port. The burner port is centered on a burner axis and has a radius. A fuel inlet structure communicates with the reaction zone through a fuel port. The fuel port is centered on a fuel port axis that is spaced radially from the burner axis a distance within a range from about twice the radius to about six times the radius. The fuel port axis is skewed relative to the burner axis to direct the fuel emerging from the fuel port to flow into the reaction zone along a spiral flow path.

Abstract: A method includes the step of extinguishing a flame fired from a burner in a reaction zone upon determining that a sensed combustion chamber temperature is at or above the auto-ignition temperature of a fuel. A subsequent step is performed before the sensed combustion chamber temperature drops below the auto-ignition temperature. The subsequent step provides a flow of the fuel through the burner and into the combustion chamber through a reaction zone outlet. This initiates diffuse combustion of the fuel by auto-ignition in the combustion chamber in the absence of a flame fired from the burner in the reaction zone.

Abstract: An apparatus to automatically raise and lower a planar member, particularly a seat, that includes a number of pivotally connected support members, all attached directly or indirectly to a base member, one of the support members being mechanically actuable, vertically extending, and vertically extendable. The seat or planar member has a range of motion that is restricted to the middle portion of the base member, the base member having a portion extending forwardly therefrom.

Abstract: A portable device is provided for generating a current in a vessel having a side-wall, the vessel containing a fluid. The device includes a housing having an inlet and an outlet, and a motor attached to the housing. A propeller, driven by the motor, is positioned in the housing. A float is attached to the housing to create a buoyant force sufficient to keep the portable device afloat in the fluid. Fluid is drawn into the housing through the inlet side and forced out of the housing through the outlet side to generate the current in the vessel.

Abstract: An apparatus is provided including a furnace structure defining a reaction chamber in which oxidant and fuel are reacted to form combustion products and having an anchor surface having an opening through which the oxidant and fuel are introduced into the reaction chamber. The reaction chamber is configured to recirculate the combustion products back toward the anchor surface. The apparatus also includes an anchor outlet configured to create a layer of combustion products directed along the anchor surface under the influence of the recirculated combustion products. The apparatus further includes a primary outlet configured to direct primary fuel to flow into the reaction chamber through the opening and the layer of combustion products so as to ignite the primary fuel.

Abstract: A burner apparatus is operated in a plurality of distinct modes. In a startup mode, flows of oxidant and primary fuel are ignited by an igniter and are provided simultaneously with a flow of secondary fuel until a process chamber reaches the auto-ignition temperature of the secondary fuel. In a subsequent mode, flows of oxidant and secondary fuel are provided simultaneously to the exclusion of a flow of primary fuel.

Abstract: Primary fuel and preheated oxidant are injected into a combustion zone to produce a flame with a predetermined adiabatic flame temperature. The preheated oxidant is injected at a target rate of oxidant injection. The primary fuel is injected at a first reduced rate which is less than a corresponding target rate of fuel injection. Secondary fuel is simultaneously injected into the combustion zone separately from the flame at a second reduced rate which is equal to the difference between the first reduced rate and the target rate of fuel injection. In this manner, combustion of the fuel with the preheated oxidant provides the amount of heat expected from the target rates of injection, while maintaining an adiabatic flame temperature that is lower than it might otherwise be if the target rate of fuel injection were provided entirely at the flame. The lower adiabatic flame temperature provides a correspondingly lower rate of NOx production.

Abstract: A capacitance measuring circuit having a sensor electrode and a reference electrode that are spaced apart so that a material can be positioned between the two electrodes. A first polarity and a second polarity voltage source are used to charge the sensor electrode and a switch controller controls the charging and discharging of a capacitor by the sensor electrode. The charge on the capacitor after being charged and at least partially discharged by the sensor electrode represents the capacitance between the sensor electrode and the reference electrode. The charge on the capacitor is used to measure the position of the material relative to the sensor and reference electrode. The measuring circuit also has a system parasitic controller to measure and adjust for system parasitic capacitance in the measuring circuit.

Abstract: An apparatus including a housing defining a heating process chamber. The housing has an opening communicating the process chamber to the ambient atmosphere. A burner is included that fires into a combustion chamber to heat gas. Also included is a collector structure located outside the opening. The collector structure is configured to collect air and exfiltrated gas from an outside area adjacent to the opening. The apparatus also includes a duct structure communicating the collector structure with the burner so as to supply the collected air and exfiltrated gas to the burner and thereby to supply combustion oxidant to the burner.

Abstract: A premix burner apparatus includes a burner structure and a firing rate control system. The burner structure defines a premix reaction zone configured to communicate with a process chamber. The burner structure further defines a plurality of separate entrances to the reaction zone, and a corresponding plurality of separate premix flow paths, each of which is configured to direct both oxidant and fuel to a respective one of the entrances to the reaction zone. The firing rate control system is operative to control flows of oxidant and fuel along at least one of the flow paths separately from flows of oxidant and fuel along at least one other flow path.

Abstract: A spreader for spreading a fabric having upper and lower sides, transversely spaced edges and longitudinally extending reenforcing cords spaced laterally across said fabric between said edges preparatory to treating the fabric in a calender, as the fabric moves in a given path to the calender. The spreader includes a mandrel having an outer generally cylindrical surface concentric with a rotational axis. The cylindrical surface has a helical groove having convolutions with a pitch generally equal to a desired cord distribution laterally of the fabric. The mandrel is rotatably mounted to a support structure such that the mandrel is positioned transverse to the fabric with the cylindrical surface of the mandrel aligned with the fabric path to be generally tangential to a side of the fabric as the fabric moves in the given path. A first motor positioned on the support structure rotates the mandrel about the axis at a given rotational speed.

Abstract: A low NOx burner and related method are disclosed including the steps of supplying a first reactant stream and introducing a second reactant stream into the first reactant stream at a first point so as to produce co-flowing streams. This resulting fuel/oxidant stream is discharged into a furnace environment having inert combustion products substantially equilibrated to furnace temperature, so as to entrain the combustion products and mix them together with the co-flowing stream. The temperature of the co-flowing stream is increased by the entrained products until it ignites in a combustion region displaced from the first point. Thus ignition cannot occur until the reactant stream has been diluted by inert products of combustion, reducing both oxygen concentration and peak flame temperature, so as to suppress NOx production.

Abstract: A spreader for spreading a fabric having upper and lower sides, transversely spaced edges and longitudinally extending tire reenforcing cords spaced laterally across said fabric between said edges preparatory to rubberizing said fabric in a calender, where the fabric moves in a given path to the calender, the spreader comprising a cantilever mounted mandrel having an outer generally cylindrical surface concentric with a rotational axis, with the cylindrical surface having a helical groove having convolutions with a pitch equal to a desired cord distribution laterally of the fabric; a mandrel support structure adjacent one edge of the fabric and having means for rotatably mounting the mandrel in a position transverse of the fabric with said cylindrical surface aligned with the fabric path to be generally tangential to a side of the fabric as the fabric moves in the given path; a first motor on the support structure for rotating the mandrel about the axis at a given rotational speed; a second motor for moving t

Abstract: A spreader for spreading a fabric having upper and lower sides, transversely spaced edges and longitudinally extending reenforcing cords spaced laterally across said fabric between said edges preparatory to treating the fabric in a calender, as the fabric moves in a given path to the calender. The spreader includes a mandrel having an outer generally cylindrical surface concentric with a rotational axis. The cylindrical surface has a helical groove having convolutions with a pitch generally equal to a desired cord distribution laterally of the fabric. The mandrel is rotatably mounted to a support structure such that the mandrel is positioned transverse to the fabric with the cylindrical surface of the mandrel aligned with the fabric path to be generally tangential to a side of the fabric as the fabric moves in the given path. A first motor positioned on the support structure rotates the mandrel about the axis at a given rotational speed.

Abstract: A method and apparatus is disclosed for heating metal billets or other separate pieces of metal in a continuous furnace using two different burner systems. The primary burner system provides the majority of available heat at relatively high flame temperatures. The secondary high velocity burner system extrains how furnace products of combustion that impinge around on the load. Thus, heat transfer and temperature uniformity is improved by forcing hot gases between the metal pieces.