Patent Application
20140051030
According to various embodiments described herein, a system can be configured for applying electricity to a combustion reaction. The electricity can be applied as or applied to a flame, or as applied to a charged flame or a flue gas generated by the flame. In some examples, the system includes an electrode feeder configured to feed a sacrificial electrode proximate to a combustion reaction. The system includes a power supply configured to apply electricity (such as a voltage waveform) to the sacrificial electrode. The sacrificial electrode is configured to apply electricity to the combustion reaction. The system can include a burner configured to support the combustion reaction.
According to an embodiment, a method includes providing a sacrificial electrode proximate to a combustion reaction. In some examples, the method includes feeding the sacrificial electrode proximate to a combustion reaction. The method includes energizing the sacrificial electrode with one or more voltages selected to induce a response to the energization in the combustion reaction. The method can be employed to operate the systems and electrodes described herein or other suitable systems or electrodes capable of operation by the method.
According to embodiments, a sacrificial electrode is be provided. The sacrificial electrode can include a bar or a wire. The sacrificial electrode can include a structural component, a conductive component, or a combination of the structural component and the conductive component. The structural component can be configured to withstand an elevated temperature corresponding to exposure to a combustion reaction. The sacrificial electrode can include one or more features configured for feeding the sacrificial electrode using an electrode feeder.
According to embodiments, a non-transitory computer readable medium carries computer-readable instructions configured to cause an electronic controller to perform operations for using a sacrificial electrode proximate to a combustion reaction. The operations can include feeding the sacrificial electrode proximate to a combustion reaction. The operations can include energizing the sacrificial electrode with one or more voltages to induce a response to the energization in the combustion reaction.
In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. Other embodiments may be used and/or other changes may be made without departing from the spirit or scope of the disclosure.
In various examples, the systems described herein can include a burner 102 configured to support the combustion reaction 104. In some examples, the systems described herein can include the sacrificial electrode 110.
In various examples, the sacrificial electrode 110 can be configured with a conductive component that can include one or more conductive materials suitable for the conditions proximate to a desired combustion reaction. In some examples, suitable conductive materials can include conductive carbon, conductive ceramics, metals, metallic alloys, mixtures or composites thereof, and the like. In several examples, the conductive carbon can include articles or composites of, for example, carbon fiber, carbon rod, carbon black, graphite, graphene, carbon nanotubes, fullerenes, conducting polymers, or the like. In many examples, conductive ceramics can include, articles or composites of, for example, indium tin oxide (ITO), lanthanum-doped strontium titanate (SLT), yttrium-doped strontium titanate (SYT), yttria-stabilized zirconia (YSZ), gadolinium-doped ceria (GDC), lanthanum strontium gallate magnesite (LSGM), beta alumina, or beta” alumina, or the like, or other ceramic materials (monolithic, composites, honeycomb or porous) that are non-conductive at room temperature but become conductive at higher temperatures. In multiple examples, suitable metals and/or metallic alloys for the conductive material can include one or more of Mg, Al, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, La, Ce, Pr, or Nd, or the like. In numerous examples, metals, metallic alloys, and ceramics can be compounded or doped with one or more of Li, Na, K, Rb, Be, B, C, Si, Ge, O, N, S, F, Cl, Br, I, or the like. In various examples, the metal or metallic alloy materials can include one or more of tungsten, steel, nickel, or cobalt.
In various examples, the sacrificial electrode 110 includes one or more conductive, insulating or semiconducting materials configured as a structural component to provide structural support to the sacrificial electrode 110. For example, the sacrificial electrode 110 can include a metal tension member configured as a structural component to provide structural support. In some examples, the structural component can be coated with a sacrificial layer. In several examples, the sacrificial layer can be the conductive component.
In various examples, the sacrificial electrode 110 can include a reactive component. In some examples, the reactive component can be the sacrificial layer. The reactive component can be made of any material described herein, configured to react with the combustion reaction, to react in the combustion reaction, to react proximate to the combustion reaction, or to react in response to the combustion reaction. The reactive component can be selected to carry out any desired reaction related to or under the influence of the combustion reaction. For example, the reactive component can include any compound or composition, such as a nitrogenous chemical reductant, which chemically reduces nitrogen atoms in a nitrogen oxide (NOx) species to molecular nitrogen (N2). In many examples, the reactive material can include urea or a salt thereof, an ammine complex, or an ammonium salt. Examples of counter-ions which form ammonium salts or urea salts can include, but are not limited to, carbamate, carbonate, bicarbonate, acetate, formate, or malate. Examples of ammine complexes can include, but are not limited to, magnesium ammine chloride Mg(NH3)6Cl2, calcium ammine chloride Ca(NH3)8Cl2, or strontium ammine chloride Sr(NH3)8Cl2.
In several examples of the systems described herein, the sacrificial electrode 110 can include a carbon rod. In many examples, the sacrificial electrode 110 can include one or more of tungsten, steel, nickel, or cobalt. In multiple examples, the sacrificial electrode 110 can include a conductive ceramic. In numerous examples, the sacrificial electrode 110 can include a reactant selected to react in the combustion reaction 104. In numerous examples, the sacrificial electrode 110 may include a catalyst selected to promote selective combustion reaction paths in the combustion reaction 104.
In various examples of the systems described herein, the sacrificial electrode 110 can include a sacrificial charge electrode configured to apply a voltage or the charge to the combustion reaction 104. In various examples, the sacrificial charge electrode may be controlled by an electrode feed controller 112 to be in at least intermittent contact with the combustion reaction 104.
The electrode feed controller 112 can use a feedback circuit or sensor (not shown) to determine when and/or where the sacrificial charge electrode is placed for desired performance. For example, the sensor can include a digital imager configured to capture an image of at least the sacrificial electrode 110. A feedback circuit can include, for example, a current sensing circuit configured to measure relative continuity between the combustion reaction 104 and the sacrificial electrode 110. For example, the burner 102 can be held at ground and the relative continuity between the combustion reaction 104 and the sacrificial electrode 110 can be proportional to current. Optionally, the electrode feed controller 112 can include a human interface configured to receive feed commands from a burner operator. Desired performance of the sacrificial electrode 110 can include placement where the combustion reaction can be just “licking” a surface of the electrode, e.g., a tip of the electrode. This can provide relatively high continuity while minimizing electrode erosion. According to another embodiment, which can be especially useful when the sacrificial electrode 110 can include an ionizing electrode and/or a field electrode, the desired performance of the electrode can be satisfied when the surface, e.g. tip of the sacrificial electrode 110 is some distance away from a flame surface. In some examples, the sacrificial electrode 110 can include a reactive surface and desired placement of the electrode can include immersion of the electrode surface, e.g., tip, in the combustion reaction 104.
In various examples of the systems described herein, the sacrificial electrode 110 can include a sacrificial field electrode configured to apply an electric field to the combustion reaction 104. In some examples, the systems described herein can include an electrode feed controller 112 configured to control at least one of a timing or a rate of electrode feeding by the electrode feeder 108. In several examples, the electrode feeder 108 includes an electrode metering or driving mechanism 114. The electrode metering or driving mechanism 114 can be configured to control at least one of a timing or a rate of electrode feeding.
In various examples, the systems described herein include a sacrificial electrode supply apparatus 116 configured to provide one or more of the sacrificial electrodes 110 to the electrode metering or driving mechanism 114. In some examples, the systems described herein include an electrode transfer mechanism 118 configured to transfer one or more of the sacrificial electrodes 110 from a sacrificial electrode supply apparatus to the electrode metering or driving mechanism 114. In several examples of the systems described herein, the sacrificial electrode supply apparatus 116 can include a hopper for holding one or more of the sacrificial electrodes 110.
In various examples of the systems described herein, the sacrificial electrode supply apparatus 116 can include an unwind reel configured to unwind the wire. In some examples of the systems described herein, the electrode metering or driving mechanism 114 can include a rewind reel configured to rewind the wire. In several examples, the systems described herein can include both the unwind reel and the rewind reel. In many examples, the sacrificial electrode supply apparatus 116 and the electrode metering or driving mechanism 114 can be configured to operate the unwind reel and the rewind reel cooperatively to unwind the wire from the unwind reel and rewind the wire on the rewind reel.
In various examples, the method 301 for using a sacrificial electrode to apply electricity to a combustion reaction can include an operation 310 of feeding a sacrificial electrode proximate to a combustion reaction. In some examples, the method 301 can include an operation 312 of energizing the sacrificial electrode with one or more voltages. In some examples, the method 301 includes an operation 314 for inducing a response to the energization in the combustion reaction.
In various examples of the method 301, the operation 312 for energizing the sacrificial electrode can include applying a time-varying voltage to the sacrificial electrode. In some examples, applying the time-varying voltage to the sacrificial electrode can include applying an alternating current (AC) voltage. In several examples, applying the time-varying voltage to the sacrificial electrode can include applying a time-varying direct current (DC) voltage. In many examples, applying the time-varying voltage to the sacrificial electrode can include applying a periodic voltage between ±8000 volts and ±40,000 volts. In multiple examples, applying the time-varying voltage to the sacrificial electrode can include applying a periodic voltage at a frequency in a range from about 50 Hz to about 1000 Hz.
In various examples, applying the time-varying voltage to the sacrificial electrode can include applying a square waveform. In several examples, applying the time-varying voltage to the sacrificial electrode can include applying a sawtooth waveform. In many examples, applying the time-varying voltage to the sacrificial electrode can include applying a triangular waveform. In multiple examples, applying the time-varying voltage to the sacrificial electrode can include applying a sinusoidal waveform. In numerous examples, applying the time-varying voltage to the sacrificial electrode can include applying a wavelet waveform. In various examples, applying the time-varying voltage to the sacrificial electrode can include applying an exponential waveform. In some examples, applying the time-varying voltage to the sacrificial electrode can include applying a logarithmic waveform. In many examples, applying the time-varying voltage to the sacrificial electrode can include applying truncations of any of the waveforms. In multiple examples, applying the time-varying voltage to the sacrificial electrode can include applying combinations thereof.
In various examples of the method 301, the operation 310 for feeding the sacrificial electrode proximate to the combustion reaction can include feeding the sacrificial electrode to act as a charge electrode to apply a voltage or a majority charge to the combustion reaction. In some examples, feeding the sacrificial electrode to act as the charge electrode can include feeding the sacrificial electrode such that a surface of the sacrificial electrode can be at least intermittently in contact with the surface of the combustion reaction. In several examples, feeding the sacrificial electrode to act as the charge electrode can include feeding the sacrificial electrode such that a tip of the sacrificial electrode can be at least intermittently in contact with a surface of a flame. In many examples, feeding the sacrificial electrode to act as the charge electrode can include feeding the sacrificial electrode such that the surface of the sacrificial electrode can be immersed in the combustion reaction. In multiple examples, feeding the sacrificial electrode to act as the charge electrode can include feeding the sacrificial electrode such that the tip of the sacrificial electrode is immersed in the combustion reaction.
In various examples of the method 301, the operation 310 for feeding the sacrificial electrode proximate to the combustion reaction can include feeding the sacrificial electrode to act as a field electrode to apply the electric field to the combustion reaction. In some examples, feeding the sacrificial electrode to act as the field electrode can include feeding the sacrificial electrode such that a surface of the sacrificial electrode is maintained at a desired distance from the combustion reaction.
In various examples of the method 301, the operation 310 for feeding the sacrificial electrode proximate to the combustion reaction can include feeding the sacrificial electrode to cause a reaction in the combustion reaction with a reactive sacrificial electrode material. For example, the sacrificial electrode can be configured to include the reactive sacrificial electrode material. In some examples, the operation 310 for feeding the sacrificial electrode to cause the reaction in the combustion reaction can include feeding the sacrificial electrode to maintain a surface area of the reactive sacrificial electrode material in contact with the combustion reaction. In multiple examples of the method 301, the operation 310 for feeding the sacrificial electrode to cause the reaction in the combustion reaction can include feeding the sacrificial electrode to cause a chemical reduction of nitrogen atoms in a nitrogen oxide (NOx) species to molecular nitrogen (N2). In numerous examples of the method 301, the operation 310 for feeding the sacrificial electrode to cause the reaction in the combustion reaction can include feeding the sacrificial electrode configured to include the urea or the salt thereof, the ammine complex, or the ammonium salt.
In various examples of the method 301, the operation 310 for feeding the sacrificial electrode proximate to the combustion reaction can include feeding the sacrificial electrode configured to include a sacrificial electrode bar. In some examples of the method 301, the operation 310 for feeding the sacrificial electrode proximate to the combustion reaction can include feeding the sacrificial electrode configured to include a sacrificial electrode wire.
In various examples of the method 301, the operation 314 for inducing the response to the energization in the combustion reaction can include controlling an emission of one or more combustion products. In some examples of the method 301, the operation 314 for inducing the response to the energization in the combustion reaction can include inducing a rate of reaction. In several examples of the method 301, the operation 314 for inducing the response to the energization in the combustion reaction can include inducing an extent of reaction. In many examples of the method 301, the operation 314 for inducing the response to the energization in the combustion reaction can include inducing a flame shape. In multiple examples of the method 301, the operation 314 for inducing the response to the energization in the combustion reaction can include inducing a combustion reaction emissivity. In numerous examples of the method 301, the operation 314 for inducing the response to the energization in the combustion reaction can include inducing a heat transfer. In numerous examples of the method 301, the operation 314 for inducing the response to the energization in the combustion reaction may include inducing enhanced flame stabilization. In various examples of the method 301, the operation 314 for inducing the response to the energization in the combustion reaction can include any combination of the inducing operations described herein.
In various examples, the method 301 can include an operation 308 for loading the sacrificial electrode into an electrode feeder. In some examples, loading the sacrificial electrode into the electrode feeder can be conducted prior to the operation 310 for feeding the sacrificial electrode proximate to the combustion reaction. In some examples, the operation 308 can include receiving the sacrificial electrode into the electrode feeder. In some examples, receiving the sacrificial electrode into the electrode feeder can be conducted prior to the operation 310 for feeding the sacrificial electrode proximate to the combustion reaction.
In various examples, the method 301 can include preparing the sacrificial electrode. In some examples, preparing the sacrificial electrode can be performed by a sacrificial electrode vendor.
In various examples, a non-transitory computer readable medium can carry computer-readable instructions configured to cause an electronic controller to perform operations for using the sacrificial electrode proximate to the combustion reaction. In some examples, the operations include feeding a sacrificial electrode proximate to a combustion reaction. In several examples, the operations can include energizing the sacrificial electrode with one or more voltages. In many examples, the operations can include inducing a response to the energization in the combustion reaction.
In further examples, the non-transitory computer readable medium carrying the computer-readable instructions can include instructions for carrying out any of the operations described herein for method 301.
In many examples, the non-transitory computer readable medium carrying the computer-readable instructions can be configured to operate the systems or electrodes described herein or other suitable systems or electrodes capable of operation by such instructions, either alone or with the electronic controller.
Referring now to
In various examples of the sacrificial electrode 110, the one or more features can include a flattened side. In some examples of the sacrificial electrode 110, the one or more features can include a diameter. In several examples of the sacrificial electrode 110, the one or more features can include a length. In many examples of the sacrificial electrode 110, the one or more features can include a taper. In multiple examples of the sacrificial electrode 110, the one or more features can include a notch. In numerous examples of the sacrificial electrode 110, the one or more features can include an electrical lug. In some examples of the sacrificial electrode 110, the one or more features can include one or more fiducial marks configured to provide positioning or movement information to a sensor that can be included in or can be operatively coupled to the electrode feeder. In various examples, the sacrificial electrode 110 may include a combination of two or more of the one or more features described herein.
In various examples of the sacrificial electrode 110, the structural component can include tungsten. In some examples of the sacrificial electrode 110, the structural component can include steel. In several examples, the structural component can include nickel. In many examples, the structural component can include cobalt. In multiple examples, the structural component can include carbon. In numerous examples, the structural component can include a conductive ceramic. In various examples of the sacrificial electrode 110, the conductive component can include tungsten. In some examples of the sacrificial electrode 110, the conductive component can include steel. In several examples, the conductive component can include nickel. In many examples, the conductive component can include cobalt. In multiple examples, the conductive component can include carbon. In numerous examples, the conductive component can include the conductive ceramic. In various examples, the combination of the structural component and the conductive component may include a combination of one or more of tungsten, steel, cobalt, nickel, carbon, or the conductive ceramic. For example, the combination of the structural component and the conductive component can include the conductive ceramic.
In various examples of the sacrificial electrode 110, the one or more features can include an unwind reel configured for mounting on an unwind apparatus of the electrode feeder. In some examples of the sacrificial electrode 110, the one or more features can include one or more fiducial marks configured to provide positioning or movement information to a sensor that can be included in the electrode feeder or operatively coupled to the electrode feeder.
In various examples of the sacrificial electrode 110, the structural component includes the wire. In some examples, the wire can include tungsten. In several examples, the wire can include steel. In many examples, the wire can include nickel. In multiple examples, the wire can include cobalt. In numerous examples, the wire can include a metal tension member inside a sacrificial layer. In various examples, the metal tension member may include a metal or metal alloy described herein.
In some examples, the sacrificial layer may be configured from any material described herein. For example, the sacrificial layer can include the carbon. In several examples, the conductive component can include the sacrificial layer. In several examples, the conductive component can include the sacrificial layer including the carbon.
In various examples, the sacrificial electrode 110 can include a reactive or catalyst component configured to react upon exposure to the combustion reaction. In some examples, the reactive component can be configured to chemically reduce nitrogen atoms in a nitrogen oxide (NOx) species to molecular nitrogen (N2). In several examples, the reactive component can include the urea or the salt thereof, the ammine salt, or the ammonium salt.
While various aspects and embodiments have been disclosed herein, other aspects and embodiments are contemplated. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
The present application claims priority benefit from U.S. Provisional Patent Application No. 61/684,106, entitled “COMBUSTION SYSTEM WITH A SACRIFICIAL ELECTRODE FOR APPLYING A VOLTAGE”, filed Aug. 16, 2012; which, to the extent not inconsistent with the disclosure herein, is incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61684106 | Aug 2012 | US |
