Active and passive combustion stabilization for burners for highly and rapidly changing fuel gas compositions.

Abstract

A burner apparatus and method are described. The burner apparatus includes an inlet chamber in communication with a combustion chamber. A primary conduit delivers fuel gas to the combustion chamber. A plurality of primary tips are each disposed within a throat of a burner tile. A plurality of cavities are each disposed in a downstream wall of the burner tile to stabilize a flame. The primary tips have an end port and a side port. A secondary conduit delivers fuel gas to a plurality of secondary tips. In a passive control mode, the fuel gas to the primary and secondary tips is a mixed gas including flue gas and fuel gas. In an active mode, a valve is provided to proportionally supply an amount of fuel gas supplied to the primary tip and an amount of flue gas supplied to the secondary tip.

Description

[Technical field]

[0001] (Statement of priority) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 167,286, filed on March 29, 2021, which is incorporated herein by reference in its entirety.

[0002] FIELD OF THEINVENTION The present disclosure relates generally to features of mixed fuel gas burners, and more particularly to burners having a cavity that allows stable combustion over a wide range of fuel gas compositions for use in passive or active burner control systems, as well as methods of operating such burners. [Background technology]

[0003] Waste gas burner systems are used to combust low BTU mixed gas streams produced by various processes in chemical processing facilities. Such processes include furnaces with many burners that burn fuel to produce heat. It is important to achieve efficient and stable combustion of mixed gas streams with various contents while minimizing the use of high BTU fuel gases.

[0004] In the future, increased regulations of gas streams emitted to the atmosphere can be expected. Additionally, current and future carbon dioxide (CO2) removal technologies for natural gas streams result in waste gas streams with varying fuel content. Process heaters and furnaces for low carbon and carbon capture processes must accommodate highly and rapidly varying fuel gases and operate seamlessly. For example, fuel gas compositions can vary widely and rapidly, e.g., from 100% methane to 100% hydrogen, or 100% natural gas to 100% PSA purge gas, with or without CO2 in the purge gas. Also, available fuel pressures can vary from 1 or 2 psig to about 30 psig (0.07 to 2.07 barg).

[0005] Operators require furnaces, heaters, and their burners to operate continuously, reliably, efficiently, and with low NOx emissions regardless of available fuel gas. Current burners cannot accommodate highly variable fuels such as those that may be required for low carbon or carbon sequestration operation, but this disclosure facilitates these highly variable fuel gases.

[0006] Therefore, there is a need for a burner system that can operate and be integrated with existing separation systems. There is also a need for a burner system that is designed to enhance burner stability over a wide range of operating conditions, thereby minimizing NOx production. Summary of the Invention

[0007] The present invention provides a burner comprising: a plenum; a burner tile configured to provide combustion air from the plenum through the burner tile to a combustion zone, the burner tile having an upstream portion, a throat, and a downstream portion, the downstream portion having a wall and a plurality of cavities disposed in the wall; and at least one primary conduit having a plurality of primary tips configured to inject a fuel stream including a fuel gas into the combustion zone, each of the primary tips including a plurality of ports.

[0008] A second aspect of the present invention is a burner comprising: a plenum; a burner tile arranged such that combustion air from the plenum flows from the plenum through the burner tile to a combustion zone, the burner tile having an upstream portion, a throat, and a downstream portion, the downstream portion having a wall, the burner tile further comprising a plurality of cavities disposed in the wall; at least one primary conduit having a plurality of primary tips configured to inject a fuel stream including a fuel gas into the combustion zone; at least one secondary conduit having a plurality of secondary tips configured to inject a second fuel stream; at least one sensor configured to sense one or more aspects of the combustion zone; a valve in fluid communication with the primary conduit and the secondary conduit; and a controller that receives input from the at least one sensor and is configured to operate the valve to control one or more aspects of the combustion zone.

[0009] A third aspect of the invention is a process for operating a burner, the process including injecting combustion air into a combustion zone associated with a burner tile, the burner tile having an upstream portion, a throat, and a downstream portion, the downstream portion having a wall, the burner tile further comprising a plurality of cavities disposed in the wall; and injecting a first portion of a fuel gas into the combustion zone through a plurality of primary tips, the combustion air and the first portion of the fuel gas generating a flame in the combustion zone.

[0010] A fourth aspect of the invention is a process for controlling a burner, the process including: injecting combustion air into a combustion zone associated with a burner tile, the burner tile having an upstream portion, a throat, and a downstream portion, the downstream portion having a wall, the burner tile further including a plurality of cavities disposed in the wall; injecting a first portion of a fuel gas from a primary conduit through a plurality of primary tips into the combustion zone, the first portion of the fuel gas and the combustion air generating a flame in the combustion zone; injecting a second portion of the fuel gas from a secondary conduit through a plurality of secondary tips; detecting one or more aspects of the combustion zone; and controlling a ratio of the first portion of the fuel gas to the second portion of the fuel gas using a valve in fluid communication with the primary conduit and the secondary conduit.

[0011] Further aspects, embodiments and details of the invention, all of which may be combined in any manner, are set out in the following detailed description of the invention. [Brief description of the drawings]

[0012] One or more exemplary embodiments of the present disclosure are described below in conjunction with the following drawing figures. [Figure 1] FIG. 2 is a detailed cross-sectional view of the burner system. [Diagram 2] FIG. 2 is a detailed cross-sectional view of a further burner system. [Diagram 3] FIG. 2 is a detailed cross-sectional view of one embodiment of the present burner system. [Figure 4] FIG. 1 is a cross-sectional view of one embodiment of the present burner system. [Diagram 5] FIG. 2 illustrates an end view of one embodiment of the present burner system. [Figure 6A] FIG. 1 is a perspective view of one embodiment of the present burner system. [Figure 6B] FIG. 1 is a cross-sectional view of one embodiment of the present burner system. [Figure 7A] FIG. 2 is a perspective view of a further embodiment of the present burner system. [Figure 7B]FIG. 4 is a cross-sectional view of a further embodiment of a burner system of the present invention. [Figure 8] FIG. 4 is a cross-sectional view of a further embodiment of a burner system of the present invention. [Figure 9A] FIG. 1 is a cross-sectional view of an embodiment of a burner system of the present invention. [Figure 9B] FIG. 1 is a cross-sectional view of an embodiment of a burner system of the present invention. [Figure 9C] FIG. 1 is a cross-sectional view of an embodiment of a burner system of the present invention. [Figure 9D] FIG. 1 is a cross-sectional view of an embodiment of a burner system of the present invention. [Figure 9E] FIG. 1 is a cross-sectional view of an embodiment of a burner system of the present invention. [Figure 9F] FIG. 1 is a cross-sectional view of an embodiment of a burner system of the present invention. [Figure 10A] FIG. 1 illustrates an embodiment of the present burner system in an exemplary process. [Figure 10B] FIG. 1 illustrates an embodiment of the present burner system in an exemplary process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] As mentioned above, the burner system of the present disclosure includes multiple cavities for burner flame stabilization.

[0014] With these general principles in mind, one or more embodiments of the invention are described, with the understanding that the following description is not intended to be limiting.

[0015] Stabilization cavities can be used as flame holders in supersonic combustors and, to a lesser extent, in subsonic burners due to their excellent potential to stabilize combustion without excessive total pressure loss. The stabilization cavity creates an environment for establishing a stable and continuously operable flame front over a reasonable operating range for a given set of combustion operating conditions. The operating conditions can vary, and some of the variables can include the composition of the fuel gas, the available pressure, and the heating value. Additionally, the oxygen content, temperature, and pressure of the combustion air or oxidant can vary. As an example, the fuel gas composition can vary to consist of 0% to 100% methane by volume, 0% to 100% hydrogen by volume, 0% to 100% CO2 or N2 by volume, 0% to 100% propane by volume, etc., with the remainder consisting of various combustible and non-combustible gases. Additionally, the fuel pressure available to the burner can vary from near 0 psig to over 100 psig (0 to 6.9 barg). Meanwhile, the air pressure available to the burner can vary from near 0 psig to over 100 psig (0 to 6.9 barg), and the change in variables can occur within a matter of seconds. The oxygen content of the combustion air or oxidizer can vary from 100% oxygen by volume to less than 5% by volume, and the temperature can vary from -50 to 1,200°F (-45.5 to 649°C).

[0016] Burners utilizing cavities for stabilization are typically optimized for a relatively narrow variability in operating conditions; for example, 100% natural gas (nearly 100% methane, i.e., fuel gas "A" in FIG. 1) may be made available to the burner at 1-20 psig (0.07-1.38 barg) at ambient atmospheric conditions, 21% oxygen at temperatures of -20 to 120°F (-29 to 49°C) at WC 0.5 inches above available atmospheric pressure. A detailed view of a burner 10 having a burner tile 30 with a single cavity 44 is shown in FIG. 1. The cavity 44 has dimensions L×D and is positioned a distance M downstream from the fuel gas injection port 40 and within the combustion air stream, and may be optimized to establish (ignite) and maintain (burn) a stable flame front 50 over a range of operating conditions. The burner system 10 has a burner tile 30 with an upstream wall 32 and a downstream wall 33 on either side of the cavity 40. The fuel tip 42 has a fuel gas injection port 40 near its distal end within the combustion zone 56 .

[0017] Alternatively, for example in the case of a burner burning Pressure Swing Absorber (PSA) off-gas, the fuel may consist of 20%-25% hydrogen, 10%-15% methane, 40%-60% CO2, the remainder other combustible and non-combustible gases, available for the same natural gas burner as above, but at pressures from less than 3 psig to nearly 0 psig (0.21 to 0 barg) (Figure 2, Fuel Gas "B"). This alternative fuel can make up 0% to 100% of the burner's heat input, firing duty.

[0018] It has been discovered that control of NOx production can be achieved by providing a NOx reduction medium, such as PSA tail gas. The NOx reduction fluid can include, but is not limited to, flue gas from the combustion chamber, flue gas from the furnace heater or boiler exhaust, steam (water vapor), nitrogen, carbon dioxide, and even fuel gases, such as methane. It is known that inert gases, such as water vapor, nitrogen, and carbon dioxide, injected into the burner fuel gas or air stream can help reduce NOx emissions by lowering the partial pressure of both the fuel and air reactants, cooling them, and by transferring heat away from the combustion section of the combustion zone. Additionally, water vapor and water vapor-containing flue gas promote the water gas shift reaction (WGSR) mechanism, which catalyzes and solvates the combustion reaction. Thus, in various configurations of the present disclosure, some or all of the NOx reduction medium passes through ports in the primary and / or secondary tips to facilitate selective and targeted distribution of the NOx reduction medium at the optimal location(s) to stabilize the flame 150 in the combustion zone(s). See FIG. 3.

[0019] The burner system 20 of Figure 2 has a burner tile with flat continuous surfaces on the upstream wall 32, the intermediate wall 35, and the downstream wall 33. A cavity 44 is provided at a downstream location relative to the cavity of Figure 1. When burning 100% PSA off-gas, a cavity 44 of dimensions l x d located in the combustion air stream a distance m downstream from the fuel gas injection point, as shown in Figure 2, can be optimized to establish (ignite) and maintain (combust) a stable flame front 50 over a range of operating conditions.

[0020] In most existing dual fuel burner designs, i.e. burners designed to operate on both natural gas and PSA off-gas, some percentage of natural gas (assist gas) must always be present to provide a stable flame front which is then utilized to stabilize the subsequently injected PSA off-gas. The cavity simply does not exist to stabilize 100% combustion of the PSA off-gas under all conditions from light-off to normal operation.

[0021] In some cases, refinery fuel gas, i.e., fuel gas synthesized as part of refinery fuel gas (RFG), is used instead of natural gas as the assist gas. In these cases, the cavity of FIG. 1 can be optimized for RFG service.

[0022] The configuration shown in FIG. 3 comprises a burner system 60 having multiple cavities 144a-b in close proximity to the combustion zone 101. Either separate or combined fuel streams of any proportion may be injected at multiple distances (m, M, m') from the cavities at multiple injection locations and multiple cavity shapes (D×L' or d×l'). For optimal performance, the geometry is modified and further optimized from single fuel optimal dimensions of m, M, d, D, l, or L to m', M', d', D', l', or L'. In so doing, the burner can operate continuously and stably, delivering the designed process required heat (fuel gas flow rate) at the designed efficient excess air level (efficiency) and at the required flue gas exhaust emissions, e.g., of nitric oxide (NOx) formation, without interruptions or instabilities in the heater or furnace combustion process or petrochemical or refinery process as the fuel changes from 100% natural gas to 100% PSA off-gas.

[0023] In the passive case, the tip 142 of the burner system 60 is a set of manifolded fuel gas delivery pipes used to inject one or both of the premixed fuels as shown in Figure 3. In the illustrated embodiment, fuel gas A, which contains an assist gas (methane), and fuel gas B, which contains a NOx reduction mediator (such as CO2) as a PSA tail gas, are premixed. In the passive case, no information about the fuel composition or quality is required to maintain a stable flame front regardless of the fuel gas rate fed to the burner. In the passive case, the burner responds instantaneously to changes in fuel gas flow and composition.

[0024] The burner tile 130 has a substantially flat inner wall with a first portion 131 adjacent the tip 142, a first cavity 144a, an intermediate portion 133, a second cavity 144b, and a downstream portion 135, as shown in Figure 3. The first cavity has a depth D' and a length L, and has substantially flat sidewalls and rounded corners. In the illustrated embodiment, a stable flame front 150 spans the first cavity and the second cavity 144b.

[0025] Tip 142 (which may be a primary or secondary tip) includes a side port 154 and an end port 156. Side port 154 is located on the side of the primary tip and is angled toward a first portion 131 of the inner wall of burner tile 130. End port 156 is also angled toward the inner wall of burner tile 130.

[0026] When tip 142 is a secondary tip (see FIG. 4), the side ports located on the sides of the secondary tip are angled toward the outer wall 160 of the burner tile 130, and the end ports located at the distal end of the secondary tip are also angled toward the outer wall of the burner tile.

[0027] In the active case, the burner system uses separately piped and valved injection jets as shown separately in Figures 1 and 2. In this active case, information regarding the composition and flow rate of the fuel gas supplied to the burner may be used to determine which injector position(s) will be utilized at any given moment. In the active case, the flame front conditions and states are sensed with either an AI-enabled camera or high speed pressure sensors and, via computer logic, assist in determining which injection positions may be used at any given moment. See Figures 9C-9F.

[0028] In the illustrated embodiment, the number of fuel gas tips 142 is between 3 and 24, while the number of fuel gas injectors can range from 1 to 100. The cavities 144 may be of a wide variety of shapes and may have curved and undulating surfaces. This means that the cavities can be of unlimited shapes and effective quantities to accommodate a wide range of highly variable fuel gas compositions and pressures. The cavities may be applied to flat surface, flat flame burners with lengths ranging from 1 inch to 10 feet in length. The cavities may also be applied to round burners with inner diameters of 1 inch to 10 feet or larger. The cavities may be internal to the burner in the airflow stream or external to the burner.

[0029] The flue gas or other inert gas medium may be one of multiple gases supplied as fuel gas, either premixed and manifolded or injected separately, as shown in Figures 1, 2 and 3, for purposes of NOx reduction or flame temperature control.

[0030] This burner system feature can be applied to the primary, secondary, or tertiary fuel gas injection locations on the burner.

[0031] Although a dual fuel configuration has been described, this is by no means limiting and a multitude of fuel gases having highly varying fuel compositions, pressures and qualities may be delivered to the burner using the present invention, including but not limited to PSA purge gases where the CO2 has been removed (possibly for CO2 sequestration) and the fuel gas composition ranges from 40%-70% methane and 5%-30% hydrogen or CO content, with the remainder made up of other combustible and non-combustible gases.

[0032] Furthermore, the burner system is particularly well suited for applications where the fuel gas can vary from 100% natural gas (mostly methane) or liquefied petroleum gas (LPG) to 100% hydrogen combustion.

[0033] In the more general case, the burner systems of the present disclosure may be used with burners designed to accept an unlimited variety of fuel gas and combustion air compositions.

[0034] The combustion air may be turbine exhaust gas with 5% to 25% oxygen at 500-1,500°F (260-816°C).

[0035] In the illustrated embodiment, the variables M, m, L, l, and D are distances on the order of 1 / 4 to 24 inches.

[0036] Although the present invention describes in detail the nature of cavity stabilization, the ideas can be extended to another common form of combustion stabilization referred to in the literature as bluff body stabilization. The discussion of cavity stabilized combustion devices, burner configurations and specific geometries can be expanded and adapted to describe bluff body stabilized burners and burners having a combination of bluff body and cavity stabilization, which includes the majority of all low pressure drop subsonic burners.

[0037] As shown in Figure 4, the burner system 100 of the present disclosure includes an air inlet section 102 and an upstream body 105. An inlet damper 109 is provided to regulate the air inlet flow. A number of nozzles 112 are provided to monitor the burner from the upstream end of the burner tile 130. An access port 114 is provided to access the upstream portion of the burner.

[0038] A plenum chamber 124 is provided upstream of the burner tile. The burner tile 130 is made of a refractory material 128 and has an upstream wall 132 in an upstream zone, a throat 134, an inner wall downstream of the throat 134, and an outer wall downstream of the throat 134. In the illustrated embodiment, the inner wall 138 and the outer wall 160 converge toward a burner tile outlet 170.

[0039] The first fuel gas 104 and the second fuel gas 106 (which may be methane and PSA tail gas, respectively) are mixed in a mixing device 108 to provide a mixed fuel gas 110. A first portion 118 of the mixed fuel gas 110 flows through a primary conduit 140 having a plurality of fuel gas tips 142a-c. A mounting bracket for a bluff body 143 is provided adjacent the throat 134 of the burner tile. A second portion 120 of the mixed fuel gas 110 flows through a secondary conduit 141 having a plurality of secondary tips 150a-c.

[0040] A sensor 180, which may be a camera, is located downstream of the burner tile outlet 170 and pointed toward the combustion zone 101. One or more sensors 180, 182 are used to detect one or more parameters of the flame to determine and control flame stability. A controller 190 having a microprocessor is in communication with the sensors 180 and 182. Control of the fuel gas flow is further described herein in connection with the active mode.

[0041] An end view of the burner tile shows the primary and secondary chips as shown in Figure 5. Ports 152a-152c for additional secondary chips (see Figure 8) are provided between the secondary chips 150a-150c.

[0042] As shown in Figure 6A, a perspective view of the burner tile 130 shows a square base section. The downstream portion of the burner tile has an annular cross section with two cavities located in the inner wall of the downstream portion. The burner tile has ports 149a-149c for secondary tips (not shown) near the outer wall of the downstream portion. Further ports 152a-152c for further secondary tips (not shown) are provided.

[0043] FIG. 6B shows a cross-section of the burner tile. In the illustrated embodiment, the upstream portion 132, the throat 134, and the downstream portion are symmetrical about the longitudinal axis A of the burner tile. The inner wall includes a shoulder at the downstream end of the throat. The cavities 144a-144b are disposed downstream of the throat 134 and each have a circular cross-section. In the illustrated embodiment, the inner wall 138 is sloped, with the upstream cavity 144a having a diameter Da that is smaller than the diameter Db of the downstream cavity 144b. The middle portion 133 of the inner wall 138 is disposed between the cavities 144a-144b and is flat. While the illustrated embodiment shows a burner tile 130 having a circular cross-section, in other embodiments, it is contemplated that the burner tile may have one or more flat walls that preferably form a square cross-section.

[0044] The outer portion of the burner tile includes a port 149 for a secondary tip (not shown) and a further port 152 for a further tip (not shown). The outer wall 160 of the burner tile tapers inwardly to an outlet portion 170 having an annular cross section. In the illustrated embodiment, the cavity is provided in the inner surface. However, in alternative embodiments, the cavity is located on the outer surface of the burner tile adjacent the secondary tip.

[0045] As shown in Figures 7A and 7B, a further embodiment of the burner tile 230 has five cavities 244a-244e. The upstream portion 232 is inclined and the throat 234 is flat. Each of the plurality of cavities 244a-244e is disposed at a different distance relative to the throat 234 of the tile 230 in the combustion zone 201. The diameters Da-De of each of the plurality of cavities 244a-244e increase in the downstream direction. As shown in Figure 7B, the upstream cavity 244a has a minimum diameter Da and the downstream cavity 244e has a maximum diameter De. The intermediate portions 233 of the inner wall 238 disposed between the cavities 244a-244e are flat.

[0046] As shown in Figure 8, a second embodiment of a burner system 200 is shown. The burner system has a further first portion 218 of fuel gas in a further primary conduit 240 and a further second portion 220 of fuel gas in a further secondary conduit 248. A further fuel gas stream 204 is also included. The further fuel gas stream comprises a NOx reducing medium, preferably PSA tail gas. The further primary conduit comprises further primary tips 242a-242c and the further secondary conduit comprises further secondary tips 250a-250c.

[0047] As shown in Figures 9A-9F, various passive and active burner schemes for the burner systems 100, 200 are provided.

[0048] Passive Mode FIG. 9A shows the passive mode of operation. This figure shows the burner system 100 in cylindrical cross section for the passive mode of operation. It is a mixed fuel gas, fuel stream C is a premix of natural gas trim fuel 104 and PSA tail gas 106. The ratio of the smaller inner gas nozzles (primary tips 142a-142c) or primary fuel gas to the outer larger fuel gas nozzles (secondary tips 150a-150c) or tiered fuel gas is fixed by the proportional sizing of the gas jets or orifices at the end of each gas nozzle. Although only three primary (center) gas tips and three tiered or secondary (peripheral) gas tips are shown, there may be multiple of each tip on a given burner. In most cases, there are many similar burners in a given furnace service.

[0049] In this passive embodiment, the fuel gas naturally finds flame stability in a suitable cavity or cavities 144a, 144b located immediately downstream of the primary gas injection nozzles (primary tips 142a-142c). As the fuel gas composition, flow rate, and pressure change and the overall stoichiometry of the burner changes, the location or locations of the fuel gas stabilization will naturally move utilizing the cavities 144a, 144b in search of stabilization.

[0050] 9B shows a further passive mode with two fuel streams. This scheme shows two separate fuel gas streams 104, 106 to two separate sets of primary tips (primary tips 142a-c and further primary tips 242a-c) and secondary fuel gas nozzles (secondary tips 150a-c and further secondary tips 250a-c). This arrangement is passive in that all gas streams from the process unit are received by the burner(s) when fuel stream B is PSA tail gas. Fuel stream A can represent trim fuel, natural gas, or refinery gas that is adjusted to achieve the process outlet temperature requirements.

[0051] This scheme is passive for the same reasons as Scheme A. In either Scheme A or B, the ratio of primary fuel to secondary fuel, either fuel or any fuel gas stream, can vary from 0% to 100%. For example, fuel stream A may be 100% magnitude to the burner primary and fuel stream B may be 100% secondary or stepped. These ratios are fixed by design in the passive case.

[0052] Active Mode 9C illustrates an active mode. In the active case, one or more sensors or operational data can be used to monitor or predict flame conditions, flame stability and shape, and NOx and other emission levels. In the active case, sensors may be used alone or in concert with other sensors. A microprocessor or similar device regulates a valve located in the fuel flow stream between the primary and secondary gas streams. In the illustrated embodiment, the valve 208 may be one or more control valves, preferably a three-way control valve.

[0053] Sensors for adjustment of the proportioning valve may include, but are not limited to, flow meters, pressure sensors, thermocouples, chromatographs, calorimeters, oxygen sensors, cameras, flame ionization detectors, photoionization detectors, multispectral flame detectors including infrared and ultraviolet flame scanners, and combination UV / IR detectors. Cameras include field of view cameras, infrared cameras, and full spectrum cameras.

[0054] The fuel gas flow rate is measured in the first conduit and / or the second conduit, allowing the burner system to sense changes in fuel supply conditions. Changes in fuel pressure and temperature to the burner(s) can also be measured in the first and second conduits.

[0055] The fuel composition can be confirmed from an online gas chromatograph, as can the fuel heating value from an online calorimeter.

[0056] Other downstream parameters can be measured to reflect the operating conditions of the burner. Furnace operating parameters include firebox and combustion air duct pressures, flue gas oxygen, nitric oxide, carbon monoxide, unburned hydrocarbon, and volatile organic compound emission concentrations in the flue gases, radiant section flue gas temperature, and process inlet and outlet temperatures.

[0057] The sensor 180 in the illustrated embodiment is a field of view or multispectral (into the IR or UV spectrum) camera for artificial intelligence imaging (depicted in FIG. 4). It is important that the camera 180 is positioned so that it can view the flame present on the multiple cavities 144a-144b in the burner tile walls within the combustion zone 101.

[0058] An additional sensor 182 is a fast furnace combustion chamber pressure transmitter (shown in FIG. 4). Additional UV and / or IR flame detectors are not shown.

[0059] Thus, additional furnace or process unit operating history or predictive data can be used in conjunction with parameters obtained from the sensors described herein to control flame stability. The operating data can include, but is not limited to, predicted fuel gas composition in relation to fuel gas pressure; burner stability predictions for various combustion cases or sets of operating conditions; emissions of NOx, CO, oxygen, unburned hydrocarbons, and volatile organic compounds.

[0060] The burner system is operated in an active mode by monitoring a series of operating conditions via sensors 180 and 182. A controller 190 receives input signals and generates output signals to control one or more valves, thus optimizing flame stability.

[0061] For example, at ignition or start-up, the firebox temperature is cool, close to ambient, and much lower than 1,400°F (760°C), and substantially all or a greater percentage of the fuel can be directed to the inner primary gas tip, thereby ensuring flame stability while minimizing CO emissions. In this mode, the multispectral camera can function as a flame detector. Then, as the firebox temperature rises near or above 1,400°F (760°C), some of the fuel can be directed to the stage gas nozzle, and CO emissions should go to zero and NOx emissions will rise. As the firebox temperature increases further, the fuel gas flow through the primary tip can be shut off entirely, minimizing NOx formation.

[0062] If the AI ​​camera imagery indicates unstable operation or operation outside of baseline image tolerances, fuel may be diverted more toward the primary gas tip and less toward the secondary gas tip.

[0063] Additionally, the fast pressure transmitter data is compared to a baseline stable / unstable pressure fluctuation signature and the primary fuel gas can be reduced until the onset of instability is reached and the primary fraction can be increased slightly to achieve operational stability with the lowest NOx for a given fuel gas.

[0064] This high speed pressure transmitter 182 is primarily a control sensor rather than an alarm or shutdown sensor. The pressure sensor data is used to adjust the primary / secondary fuel split or ratio.

[0065] The lowest NOx emissions may be produced when the burner 10 is receiving the highest percentage of NOx reduction media, but this may also be the initiation point of burner instability. However, this initiation instability can be detected by a high speed pressure transmitter and associated instability detection software similar to that described in U.S. Patent No. 7,950,919 to Johnson et al. However, unlike U.S. Patent No. 7,950,919 where primarily the combustion chamber oxygen is controlled and adjusted in response to the instability, in the present disclosure the speed and position of the NOx reduction media can be controlled.

[0066] Typically, NOx emissions from the heater can be monitored along with stack oxygen and combustion chamber pressure or draft. The rate and amount of NOx reduction media supplied is increased at the desired location in the flame zone until the required NOx reduction is achieved. Once the desired NOx level is achieved, no additional NOx reduction media can be introduced. If the burner becomes unstable, the rate and / or location of the NOx reduction media can be controlled or excess air, oxygen levels can be adjusted as suggested in U.S. Pat. No. 7,950,919 until burner stability is achieved.

[0067] It is further contemplated that a field of view or infrared camera may be used to monitor flame stability and quality aspects using artificial intelligence (AI) as described in U.S. Patent Application Publication No. 2020 / 0386404. If instability or other anomalies in the flame image are detected by the AI, other control aspects of the heater control system, such as the amount and location of NOx reduction media and / or excess oxygen, can be adjusted and controlled to deliver minimum levels (or at least required levels) of NOx while simultaneously providing good burner flame stability.

[0068] Even if there is a loss of NOx reduction media at any time or moment, the burner 10 of the present invention operates safely as a conventional low NOx burner. NOx emissions may increase, but otherwise the burner 10 remains stable and continues to reliably provide heat to the process in the heater, boiler, or furnace. Moreover, from the burner operator's point of view, the burner 10 operates exactly the same as a conventional burner would operate, without any special operational problems.

[0069] The introduction of the NOx reduction media is by fixed static control devices or by automatic computer control. Thus, from the operator's perspective, the burner is operated conventionally with draft and oxygen management as specified in API Recommended Practice 535, Third Edition, May 2014, Burners for Fired Heaters in General Refinery Service. That is, draft and oxygen are controlled by stack dampers and burner air inlet registers and / or induced draft and forced draft fan control settings.

[0070] Those skilled in the art will recognize and understand that various other components, such as valves, pumps, filters, coolers, etc., may not be shown because the details thereof are within the knowledge of those skilled in the art and the description of them is not believed to be necessary to make or understand embodiments of the present invention.

[0071] Any of the above lines, conduits, units, devices, vessels, ambient environments, zones, or the like may be equipped with one or more monitoring components, including sensors, measurement devices, data capture devices, or data transmission devices. Signals, process, or condition measurements, and data from the monitoring components may be used to monitor conditions in, around, and on the process equipment. Signals, measurements, and / or data generated or recorded by the monitoring components may be collected, processed, and / or transmitted over one or more networks or connections, which may be private or public, general or specific, direct or indirect, wired or wireless, encrypted or unencrypted, and / or combination(s) thereof. This specification is not intended to be limiting in this respect.

[0072] Signals, measurements, and / or data generated or recorded by the monitoring components may be transmitted to one or more computing devices or systems. The computing devices or systems may include at least one processor and a memory storing computer-readable instructions that, when executed by the at least one processor, cause the one or more computing devices to perform a process that may include one or more steps. For example, the one or more computing devices may be configured to receive data related to at least one piece of equipment associated with the process from the one or more monitoring components. The one or more computing devices or systems may be configured to analyze the data. Based on the analysis of the data, the one or more computing devices or systems may be configured to determine one or more recommended adjustments to one or more parameters of one or more processes described herein. The one or more computing devices or systems may be configured to transmit encrypted or unencrypted data including one or more recommended adjustments to one or more parameters of one or more processes described herein.

[0073] The computing devices of the system units may comprise, for example, any type of general-purpose microprocessor or microcontroller, a digital signal processing (DSP) processor, a central processing unit (CPU), an integrated circuit, a field programmable gate array (FPGA), a reconfigurable processor, other suitably programmed or programmable logic circuitry, or any combination thereof.

[0074] The memory may be any suitable known or other machine-readable storage medium. The memory may include a non-transitory computer-readable storage medium, such as, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. The memory may include any suitable combination of any type of computer memory located either internal or external to the device, such as, for example, random access memory (RAM), read-only memory (ROM), compact disc read-only memory (CD-ROM), electro-optical memory, magneto-optical memory, erasable programmable read-only memory (EPROM), and electrically erasable programmable read-only memory (EEPROM), ferroelectric RAM (FRAM), etc. The memory may include any storage means (e.g., device) suitable for removably storing computer-executable instructions executable by a controller or computing device.

[0075] The methods and processes described herein may be implemented in a high-level procedural or object-oriented programming or scripting language, or a combination thereof, to communicate with or assist in the operation of a controller or computing device. Alternatively, the methods and systems described herein may be implemented in assembly or machine language. The language may be a compiled or interpreted language. Program code for implementing the methods and systems for controlling gas flow to a burner described herein may be stored on a storage medium or device, such as a ROM, a magnetic disk, an optical disk, a flash drive, or any other suitable storage medium or device. The program code may be readable by a general-purpose or special-purpose programmable computer to configure and operate the computer when the storage medium or device is read by the computer to perform the procedures described herein.

[0076] Computer-executable instructions may be in many forms, including program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Typically the functionality of the program modules may be combined or distributed as desired in various embodiments.

[0077] 9D shows a further active mode. Whereas scheme C accommodates a single fuel flow stream to a single set of primary and secondary tips, scheme D can be used to accommodate multiple sets of primary and secondary tips. One set of injection nozzles (primary tips 142a-c and secondary tips 150a-c) is designed for high pressure natural gas or refinery gas nozzles, and a further set (further primary tips 242a-c and further secondary tips 250a-c) is designed for 14.5-29 psig (1-2 barg). The second set of tips (further primary tips 242a-c and further secondary tips 250a-c) is designed for lower pressure process off-gas or tail gas, preferably about 2-5 psig (0.14-0.34 barg). As the input data on fuel composition and pressure changes and the sensor data changes, the percentage for each set of gas chips can be changed proportionally via control valve 208 from 100% for one set to 100% for the other set, changing the ratio between the two.

[0078] By changing the proportion of fuel gas delivered to the primary tips 142a-142c and secondary tips 150a-150c in Scheme C, or the high / low pressure in Scheme D, the stabilization cavity(ies) for which a set of gas nozzles is optimized to deliver and produce a stable flame is changed.

[0079] 9E shows a further active mode. Using scheme E, the burner system 200 can actively accommodate two or more highly variable fuel sources 104, 106 and a further fuel gas stream 111 that varies in both composition and pressure. Multiple control valves 208a, 208b are used to separately vary the mixed fuel gas flow to separate sets of gas nozzles with variable primary / secondary gas ratios and direct the gas to specific stabilization cavities as optimized for different cases.

[0080] 9F shows a further active mode. In scheme F, highly variable mixtures or single fuel sources can be actively accommodated. Three control valves 208a-c are used to vary both composition and pressure by separately varying the primary / secondary split of two or more separate sets of gas tips with the ability to fully switch from one set to another. One set of nozzles (primary tips 142a-c and secondary tips 150a-c) is optimized for high pressure fuel gas with a design pressure above 14.5 psig (1 barg) and the other set (additional primary tips 242a-c and additional secondary tips 250a-c) is designed for low pressure fuel gas with a design pressure below 3 psig (0.2 barg). EXAMPLES

[0081] 10A and 10B, the fuel stream entering the burner system 100 (or burner system 200) in the exemplary process 300, 400 is shown with a CO2 capture mode and a bypass mode. In the illustrated embodiment, the burner system 100 is attached to a steam methane reforming unit (SMR). The first fuel source is natural gas and the second fuel gas stream is a PSA tail gas stream.

[0082] Additionally, fuel gas streams, whether mixed or separated, can further vary in composition from 100% natural gas (mostly methane), to 100% pure hydrogen, to refined fuel gas blends (composed of varying amounts of methane, hydrogen, and heavier gaseous hydrocarbons).

[0083] There may be one, two, three or more rapidly changing fuel gas streams fed to these burners.

[0084] Note that the chemical processing unit produces PSA tail gas and all produced PSA tail gas must be sent to and consumed by the burner. However, this PSA tail gas is not sufficient to maintain the process outlet temperature requirements, so additional "trim" gas is used to achieve the desired process temperature.

[0085] The following table shows an exemplary embodiment. In an embodiment where the fuel gases are premixed, the mixed fuel column shows the components of the mixed fuel stream. In an embodiment where the first fuel gas is PSA tail gas (a fuel stream containing one or more NOx reducing media) and the second fuel gas is natural gas (NG), the following table shows the composition of the fuel stream.

[0086] [Table 1]

[0087] [Table 2]

[0088] In the above table, when operating in passive mode, the mixed fuel represents the content of the common fuel gas stream sent to the primary and secondary chips. The above table shows how the Cl content increases dramatically and the CO2 decreases when the system changes from bypass mode to carbon dioxide capture mode.

[0089] In active mode, NG (natural gas) stream 104 is the fuel gas sent to the primary chip, and PSA tail gas 106 is the secondary fuel stream sent to the secondary chip. In bypass mode, shown in Figure 14B, PSA tail gas is received from the hydrogen PSA system. In CO2 capture mode, shown in Figure 14A, PSA tail gas is generated from an additional PSA system.

[0090] Specific Embodiments While the following is described in conjunction with specific embodiments, it will be understood that this description is illustrative of the foregoing description and appended claims and is not intended to be limiting.

[0091] A first embodiment of the present invention is a burner comprising: a plenum; a burner tile configured to provide combustion air from the plenum through the burner tile to a combustion zone, the burner tile having an upstream portion, a throat, and a downstream portion, the downstream portion having a wall and a plurality of cavities disposed in the wall; and at least one primary conduit having a plurality of primary tips configured to inject a fuel stream comprising a fuel gas into the combustion zone, each of the primary tips including a plurality of ports. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the first embodiment of this paragraph, further comprising at least one secondary conduit having a plurality of secondary tips configured to inject a second portion of a second fuel stream downstream of the primary tips. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the first embodiment of this paragraph, wherein the secondary tips are disposed radially outward relative to the primary tips, and the secondary tips are disposed along an outer wall of the burner tile. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the first embodiment of this paragraph, where the wall of the burner tile is an inner wall with a curved shoulder and a planar portion, and each of the plurality of cavities is disposed on the planar portion. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the first embodiment of this paragraph, where the burner tile has an annular cross-section, and each of the plurality of cavities is defined by a curved cross-section. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the first embodiment of this paragraph, where each of the plurality of cavities has a different diameter and is disposed at a different distance relative to the throat of the burner tile. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the first embodiment of this paragraph, where each primary tip comprises a side port and an end port, and the side port is disposed on a side of the primary tip and angled toward the inner wall of the burner tile.An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the first embodiment of this paragraph, where each end port is located at a distal end of the primary tip and angled towards the wall of the burner tile. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the first embodiment of this paragraph, where each secondary tip comprises a side port and an end port, where the side port of each secondary tip is located at a side of the secondary tip and angled towards the outer wall of the burner tile, and where the end port of each secondary tip is located at a distal end of the secondary tip and angled towards the outer wall of the burner tile. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the first embodiment of this paragraph, where the first conduit comprises a plurality of further secondary tips and the second conduit comprises a plurality of further primary tips.

[0092] A second embodiment of the present invention is a burner comprising: a plenum; a burner tile arranged such that combustion air from the plenum flows from the plenum through the burner tile to the combustion zone, the burner tile having an upstream portion, a throat, and a downstream portion, the downstream portion having a wall, the burner tile further comprising a plurality of cavities disposed in the wall; at least one primary conduit having a plurality of primary tips configured to inject a fuel stream including a fuel gas into the combustion zone; at least one secondary conduit having a plurality of secondary tips configured to inject a second fuel stream; at least one sensor configured to sense one or more aspects of the combustion zone; a valve in fluid communication with the primary conduit and the secondary conduit; and a controller receiving input from the at least one sensor, the controller configured to operate the valve to control one or more aspects of the combustion zone. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, up to and including the second embodiment of this paragraph, wherein the second portion of the fuel gas is injected downstream relative to the first portion of the fuel gas. An embodiment of the invention is any one, any or all of the previous embodiments of this paragraph, including up to the second embodiment of this paragraph, where the wall of the burner tile is an inner wall. An embodiment of the invention is any one, any or all of the previous embodiments of this paragraph, including up to the second embodiment of this paragraph, where the sensor is one of a camera, a pressure sensor, a thermocouple, a flame detector, a calorimeter, or a chromatograph. An embodiment of the invention is any one, any or all of the previous embodiments of this paragraph, including up to the second embodiment of this paragraph, where the valve is a three-way control valve configured to control a proportion of the fuel gas flow in the primary conduit and a proportion of the fuel gas flow in the secondary conduit. An embodiment of the invention is any one, any or all of the previous embodiments of this paragraph, including up to the second embodiment of this paragraph, where the first conduit comprises a plurality of additional secondary tips and the second conduit comprises a plurality of additional primary tips.An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the second embodiment of this paragraph, where the valve is a three-way control valve configured to control the proportion of fuel gas flow in the primary conduit and the proportion of fuel gas flow in the secondary conduit, and the further control valve is configured to control the proportion of fuel gas flow in the plurality of further secondary chips and the plurality of further primary chips. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the second embodiment of this paragraph, where the valve is a three-way control valve configured to control the proportion of fuel gas flow in the primary conduit and the proportion of fuel gas flow in the secondary conduit, and the further three-way control valve is configured to control the proportion of fuel gas flow in the plurality of further secondary chips and the plurality of further primary chips, and a main valve is provided in communication with a mixed gas source, controlling the proportion of the mixed gas to the three-way control valve and the further control valve. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the second embodiment of this paragraph, where the burner tile has an annular cross-section, and each of the plurality of cavities is defined by a curved wall.

[0093] A third embodiment of the present invention is a process of operating a burner, the process including injecting combustion air into a combustion zone associated with a burner tile, the burner tile having an upstream portion, a throat, and a downstream portion, the downstream portion having a wall, the burner tile further comprising a plurality of cavities disposed in the wall, and injecting a first portion of a fuel gas into the combustion zone through a plurality of primary tips, the combustion air and the first portion of the fuel gas generating a flame in the combustion zone. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including through the third embodiment of this paragraph, and injecting a second portion of the fuel gas through a plurality of secondary tips, the second portion of the fuel gas including a NOx reduction medium. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including through the third embodiment of this paragraph, and the second portion of the fuel gas is injected downstream relative to the first portion of the fuel gas. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the third embodiment of this paragraph, where each of the primary tips injects a first portion of the fuel gas through a side port and an end port. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the third embodiment of this paragraph, where the side port is located on a side of the tip and angled towards the inner wall of the burner tile. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the third embodiment of this paragraph, where each end port is located at a distal end of the primary tip and angled towards the inner wall of the burner tile. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the third embodiment of this paragraph, where each secondary tip comprises a side port and an end port, where the side port of each secondary tip is located on a side of the tip and angled towards the outer wall of the burner tile.One embodiment of the present invention is one, any, or all of the previous embodiments in this paragraph, including the third embodiment in this paragraph, wherein the end port of each secondary tip is located at a distal end of the secondary tip and angled toward the outer wall of the burner tile.

[0094] A fourth embodiment of the present invention is a process for controlling a burner, the process including: injecting combustion air into a combustion zone associated with a burner tile, the burner tile having an upstream portion, a throat, and a downstream portion, the downstream portion having a wall, the burner tile further including a plurality of cavities disposed in the wall; injecting a first portion of a fuel gas from a primary conduit through a plurality of primary tips into the combustion zone, the first portion of the fuel gas and the combustion air generating a flame in the combustion zone; injecting a second portion of the fuel gas from a secondary conduit through a plurality of secondary tips; detecting one or more aspects of the combustion zone; and controlling a ratio of the first portion of the fuel gas to the second portion of the fuel gas using a valve in fluid communication with the primary conduit and the secondary conduit. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including through the fourth embodiment of this paragraph, where the second portion of the fuel gas is injected downstream relative to the first portion of the fuel gas. An embodiment of the invention is one, any, or all of the previous embodiments of this paragraph, including through the fourth embodiment of this paragraph, further comprising providing a second portion of the fuel gas from a pressure swing absorption vessel.An embodiment of the invention is one, any, or all of the previous embodiments of this paragraph, including through the fourth embodiment of this paragraph, further comprising providing a second portion of the fuel gas that bypasses the pressure swing absorption vessel.An embodiment of the invention is one, any, or all of the previous embodiments of this paragraph, including through the fourth embodiment of this paragraph, further comprising monitoring at least one NOx value of the flame and adjusting the flow rate of the flue gas based on the at least one NOx value. One embodiment of the present invention is one, any or all of the previous embodiments of this paragraph up to the fourth embodiment of this paragraph, wherein the first conduit comprises a plurality of further secondary chips, the second conduit comprises a plurality of further primary chips, the valve is a three-way control valve configured to control the proportion of fuel gas flow in the primary conduit and the proportion of fuel gas flow in the secondary conduit, and the further three-way control valve is configured to control the proportion of fuel gas flow in the plurality of further secondary chips and the plurality of further primary chips.An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph up to and including the fourth embodiment of this paragraph, where the valve is a control valve configured to control a proportion of fuel gas flow in the primary conduit and a proportion of fuel gas flow in the secondary conduit, and the further control valve is configured to control a proportion of fuel gas flow in the plurality of further secondary chips and the plurality of further primary chips, and a main valve is provided in communication with a source of mixed gas and controls a proportion of the mixed gas to the control valve and the further control valve. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph up to and including the fourth embodiment of this paragraph, where the second portion of the fuel gas comprises a NOx reduction medium.

[0095] A fifth embodiment of the present invention is a burner comprising: a plenum; a burner tile configured to provide combustion air from the plenum through the burner tile to the combustion zone, the burner tile having an upstream portion, a throat, and a downstream portion, the downstream portion having a wall and a plurality of cavities disposed in the wall; and at least one primary conduit having a plurality of primary tips configured to inject a fuel stream comprising a fuel gas into the combustion zone, each of the primary tips including a plurality of ports. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including through the fifth embodiment of this paragraph, further comprising at least one secondary conduit having a plurality of secondary tips configured to inject a second portion of a second fuel stream downstream of the primary tips. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including through the fifth embodiment of this paragraph, wherein the secondary tips are disposed radially outward relative to the primary tips, and the secondary tips are disposed along an outer wall of the burner tile. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the fifth embodiment of this paragraph, where each secondary tip comprises a side port and an end port, the side port of each secondary tip being located on a side of the secondary tip and angled towards the outer wall of the burner tile, and the end port of each secondary tip being located at a distal end of the secondary tip and angled towards the outer wall of the burner tile. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the fifth embodiment of this paragraph, where at least one primary conduit comprises a plurality of further secondary tips, and at least one secondary conduit comprises a plurality of further primary tips. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the fifth embodiment of this paragraph, where the wall of the burner tile is an inner wall comprising a curved shoulder and a planar portion, and where each of the plurality of cavities is located on the planar portion.An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the fifth embodiment of this paragraph, where each primary tip comprises a side port and an end port, the side port being located on a side of the primary tip and angled towards the inner wall of the burner tile. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the fifth embodiment of this paragraph, where each end port is located at a distal end of the primary tip and angled towards the wall of the burner tile. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the fifth embodiment of this paragraph, where the burner tile has an annular cross-section and each of the plurality of cavities is defined by a curved cross-section. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including up to the fifth embodiment of this paragraph, where each of the plurality of cavities has a different diameter and is located at a different distance relative to the throat of the burner tile.

[0096] A sixth embodiment of the present invention is a burner comprising: a plenum; a burner tile arranged such that combustion air from the plenum flows from the plenum through the burner tile to the combustion zone, the burner tile having an upstream portion, a throat, and a downstream portion, the downstream portion having a wall, the burner tile further comprising a plurality of cavities disposed in the wall; at least one primary conduit having a plurality of primary tips configured to inject a first fuel stream comprising a fuel gas into the combustion zone; at least one secondary conduit having a plurality of secondary tips configured to inject a second fuel stream; at least one sensor configured to sense one or more aspects of the combustion zone; a valve in fluid communication with the primary conduit and the secondary conduit; and a controller receiving input from the at least one sensor, the controller configured to operate the valve to control one or more aspects of the combustion zone. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph, including through the sixth embodiment of this paragraph, wherein the second fuel stream is injected downstream relative to the first fuel stream. An embodiment of the invention is any one, any or all of the previous embodiments of this paragraph up to and including the sixth embodiment of this paragraph, where the wall of the burner tile is an inner wall. An embodiment of the invention is any one, any or all of the previous embodiments of this paragraph up to and including the sixth embodiment of this paragraph, where the at least one sensor is one of a camera, a pressure sensor, a thermocouple, a flame detector, a calorimeter, or a chromatograph. An embodiment of the invention is any one, any or all of the previous embodiments of this paragraph up to and including the sixth embodiment of this paragraph, where the valve is a three-way control valve configured to control a proportion of a flow rate of the first fuel stream in the at least one primary conduit and a proportion of a flow rate of the second fuel stream in the at least one secondary conduit. An embodiment of the invention is any one, any or all of the previous embodiments of this paragraph up to and including the sixth embodiment of this paragraph, where the at least one primary conduit comprises a plurality of further secondary tips, and the at least one secondary conduit comprises a plurality of further primary tips.An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph up to and including the sixth embodiment of this paragraph, wherein the valve is a three-way control valve configured to control a proportion of a flow rate of the first fuel stream in the at least one conduit and a proportion of a flow rate of the second fuel stream in the at least one secondary conduit, and further comprising a further control valve configured to control a proportion of a flow rate of the first fuel stream in a plurality of further secondary tips and a proportion of a flow rate of the second fuel stream in a plurality of further primary tips.An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph up to and including the sixth embodiment of this paragraph, wherein the burner tile has an annular cross-section and each of the plurality of cavities is defined by a curved wall.

[0097] A seventh embodiment of the present invention is a process of operating a burner, the process including: injecting combustion air into a combustion zone associated with a burner tile, the burner tile having an upstream portion, a throat, and a downstream portion, the downstream portion having a wall, the burner tile further including a plurality of cavities disposed in the wall; injecting a first portion of a fuel gas into the combustion zone through a plurality of primary tips, the combustion air and the first portion of the fuel gas generating a flame in the combustion zone; and injecting a second portion of the fuel gas through a plurality of secondary tips. An embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph through the seventh embodiment of this paragraph, further including detecting one or more aspects of the combustion zone and controlling a ratio of the first portion of the fuel gas to the second portion of the fuel gas using valves in fluid communication with the primary and secondary tips.

[0098] Without further elaboration, it is believed that, using the preceding description, one skilled in the art can utilize the present invention to its fullest extent and easily ascertain the essential characteristics of the present invention without departing from the spirit and scope of the present invention, and can make various changes and modifications to the present invention to adapt it to various uses and conditions. The preceding preferred specific embodiments are therefore to be construed as merely illustrative, and are not limitative of the remainder of the disclosure in any way, but are intended to cover various modifications and equivalent arrangements falling within the scope of the appended claims.

[0099] Above, all temperatures are set forth in degrees Celsius and all parts and percentages are by weight unless otherwise stated.

[0100] In the above detailed description of the present invention, at least one exemplary embodiment has been presented, but it should be understood that a vast number of variations exist. It should also be understood that the exemplary embodiment is merely illustrative and is not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the above detailed description provides those skilled in the art with a convenient guide for implementing the exemplary embodiments of the invention, and it should be understood that various changes may be made in the functions and arrangement of elements described in the exemplary embodiments without departing from the scope of the invention as set forth in the appended claims and their legal equivalents. <Additional Notes> [Form 1] A burner (10), The plenum and a burner tile (30, 130, 230) arranged such that combustion air from the plenum flows from the plenum through the burner tile to a combustion zone (101, 201), the burner tile having an upstream portion (132, 232), a throat (134, 234), and a downstream portion (135), the downstream portion (135) having a wall, the burner tile further comprising a plurality of cavities (44, 144a, 144b, 244a-244e) disposed in the wall; at least one primary conduit (140, 240) having a plurality of primary tips (142a-142c, 242a-242c) configured to inject a first fuel stream comprising a fuel gas into the combustion zone; at least one secondary conduit (141, 248) having a plurality of secondary tips (150a-150c, 250a-250c) configured to inject a second fuel stream; at least one sensor (180, 182) configured to sense one or more aspects of the combustion zone; a valve (208) in fluid communication with the primary conduit and the secondary conduit; a controller (190) receiving input from the at least one sensor (180, 182), the controller being configured to operate the valve to control the one or more aspects of the combustion zone. [Form 2] 2. The burner (10) of claim 1, wherein the second fuel stream is injected downstream relative to the first fuel stream. [Form 3] 2. The burner (10) of claim 1, wherein the wall of the burner tile (30, 130, 230) is an inner wall. [Form 4] 2. The burner (10) of claim 1, wherein the at least one sensor (180, 182) is one of a camera, a pressure sensor, a thermocouple, a flame detector, a calorimeter, or a chromatograph. [Form 5] 5. The burner (10) of any one of the preceding claims, wherein the valve (208) is a three-way control valve configured to control a proportion of a flow rate of a first fuel stream in the at least one primary conduit and a proportion of a flow rate of a second fuel stream in the at least one secondary conduit. [Form 6] The burner (10) according to any one of the preceding embodiments, wherein the at least one primary conduit is provided with a plurality of further secondary tips (150a-150c, 250a-250c), and the at least one secondary conduit is provided with a plurality of further primary tips (142a-142c, 242a-242c). [Form 7] the valve (208) is a three-way control valve configured to control a proportion of a flow rate of the first fuel stream in the at least one conduit and a proportion of a flow rate of the second fuel stream in the at least one secondary conduit; The burner (10) of claim 6, further comprising a further control valve (208a-208c) configured to control a proportion of a flow rate of the first fuel stream in the plurality of further secondary tips and a proportion of a flow rate of the second fuel stream in the plurality of further primary tips. [Form 8] The burner (10) according to any one of the first to fourth embodiments, wherein the burner tile (30, 130, 230) has an annular cross-section, and each of the plurality of cavities (44, 144a, 144b, 244a-244e) is defined by a curved wall. [Form 9] A process for operating a burner, comprising: injecting combustion air into a combustion zone associated with a burner tile (30, 130, 230), the burner tile (30, 130, 230) having an upstream portion (132, 232), a throat (134, 234), and a downstream portion (135), the downstream portion having a wall, the burner tile further comprising a plurality of cavities (44, 144a, 144b, 244a-244e) disposed in the wall; injecting a first portion of a fuel gas into the combustion zone through a plurality of primary tips (142a-142c, 242a-242c), wherein the combustion air and the first portion of the fuel gas generate a flame within the combustion zone; and injecting a second portion of the fuel gas through a plurality of secondary tips (150a-150c, 250a-250c). [Form 10] detecting one or more aspects of the combustion zone; 10. The process of claim 9, further comprising controlling a ratio of the first portion of the fuel gas to the second portion of the fuel gas using a valve (208) in fluid communication with the primary chip (142a-142c, 242a-242c) and the secondary chip (150a-150c, 250a-250c).

Claims

1. A burner (10), The plenum and a burner tile (30, 130, 230) arranged such that combustion air from the plenum flows from the plenum through the burner tile to a combustion zone (101, 201), the burner tile having an upstream portion (132, 232), a throat (134, 234), and a downstream portion (135), the downstream portion (135) having a wall, the burner tile further comprising a plurality of cavities (44, 144a, 144b, 244a-244e) disposed in the wall; at least one primary conduit (140, 240) having a plurality of primary tips (142a-142c, 242a-242c) configured to inject a first fuel stream comprising a fuel gas into said combustion zone; at least one secondary conduit (141, 248) having a plurality of secondary tips (150a-150c, 250a-250c) configured to inject a second fuel stream; at least one sensor (180, 182) configured to sense one or more aspects of the combustion zone; a valve (208) in fluid communication with the primary conduit and the secondary conduit; a controller (190) receiving input from the at least one sensor (180, 182), the controller being configured to operate the valve to control the one or more aspects of the combustion zone; Each of the plurality of cavities has a different diameter and is positioned a different distance relative to the throat of the burner tile.

2. The burner (10) of claim 1, wherein the wall of the burner tile (30, 130, 230) is an interior wall.

3. A burner (10) as described in claim 1 or 2, wherein the valve (208) is a three-way control valve controlling the proportion of the first fuel stream passing through the at least one primary conduit and the proportion of the second fuel stream passing through the at least one secondary conduit.

4. A process for operating a burner, comprising: injecting combustion air into a combustion zone associated with a burner tile (30, 130, 230), the burner tile (30, 130, 230) having an upstream portion (132, 232), a throat (134, 234), and a downstream portion (135), the downstream portion having a wall, the burner tile further comprising a plurality of cavities (44, 144a, 144b, 244a-244e) disposed in the wall, each of the plurality of cavities having a different diameter and disposed at a different distance relative to the throat of the burner tile; injecting a first portion of a fuel gas into the combustion zone through a plurality of primary tips (142a-142c, 242a-242c), wherein the combustion air and the first portion of the fuel gas generate a flame within the combustion zone; injecting a second portion of the fuel gas through a plurality of secondary tips (150a-150c, 250a-250c).

5. The process described in claim 4, further comprising controlling the proportion of the first portion of the fuel gas passing through the plurality of primary chips and the proportion of the second portion of the fuel gas passing through the plurality of secondary chips using a three-way control valve.

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