A low NOx burner

Abstract

The present invention discloses a low NOx burner, comprising: an air inlet housing, a fuel spray gun, a burner nozzle, a graded air distribution device, a protective air duct and a hydrogen-oxygen gas duct. The low NOx burner of the present invention, on the one hand, utilizes the high-speed spraying of hydrogen-oxygen gas greater than 200m / s and the protective air to form a spray port at the outer part of the burner nozzle, forming jets of different angles to roll up the flue gas in the furnace, and utilizes the catalytic characteristics of hydrogen-oxygen gas to improve the burnout rate and reduce the carbon black in the flue gas. At the same time, the graded air distribution device is utilized to control the combustion speed of the fuel through graded air distribution, reduce the local high temperature of the flame, and utilize a rotating airflow adjustment structure to achieve the change between the length of the combustion flame under the condition of unchanged combustion power, so that the combustion flame shape and combustion process of the fuel are controlled, thereby achieving low NOx emissions of different fuels.

Description

Technical Field

[0001] The invention relates to the field of industrial heating burners, in particular to a low NOx burner which utilizes hydrogen and oxygen injection and graded air distribution to form flue gas circulation in a furnace. Background Art

[0002] Reducing the emission of nitrogen oxides (NOx) during fuel combustion is an environmental problem that needs to be solved urgently. At present, the combustion technology for reducing NOx emissions can be divided into three major technologies: pre-combustion, combustion and post-combustion treatment. Pre-combustion denitrification mainly adopts fuel purification treatment, that is, converting the fuel into low-nitrogen fuel; during combustion, denitrification mainly adopts staged combustion to change the combustion conditions in the furnace to reduce NOx generation: such as air staging, fuel staging and flue gas circulation combustion; post-combustion treatment methods include selective catalytic reduction, non-catalytic selective reduction, flue gas denitrification, etc. Summary of the invention

[0003] The main technical problem solved by the present invention is to provide a low NOx burner, which can use hydrogen and oxygen injection and its graded air distribution to form flue gas circulation in the furnace, use the catalytic properties of hydrogen and oxygen to improve the burnout rate and reduce the carbon black in the flue gas, and use the graded air distribution device to control the combustion flame shape and combustion process of the fuel, thereby achieving low NOx emissions from different fuels.

[0004] In order to solve the above technical problems, a technical solution adopted by the present invention is to provide a low NOx burner, including: an air inlet housing, a fuel spray gun, a burner nozzle, a graded air distribution device, a protective air guide pipe and a hydrogen and oxygen guide pipe,

[0005] The air inlet housing comprises an internal cavity, an air inlet, an air outlet and a rear cover;

[0006] The burner nozzle is connected to the air outlet;

[0007] The graded air distribution device includes an air regulating device, a primary air flow channel, a secondary air flow channel and a rotating air flow regulating structure; the air regulating device is installed at the air inlet of the air inlet shell; the primary air flow channel and the secondary air flow channel are located in the internal cavity of the air inlet shell, and the primary air flow channel and the secondary air flow channel are relatively independent; the air regulating device includes an air regulating plate, the air regulating plate can rotate and stay in at least two extreme positions, when the air regulating plate is in the middle position, the inlet of the primary air flow channel and the inlet of the secondary air flow channel are opened at the same time; when the air regulating plate is in the first extreme position, the inlet of the secondary air flow channel is closed, and the inlet of the primary air flow channel is opened; when the air regulating plate is in the second extreme position, the inlet of the primary air flow channel is closed, and the inlet of the secondary air flow channel is opened; the rotating air flow regulating structure includes an air inlet channel, the air inlet channel is connected to the first air flow channel, the rotating air flow regulating structure is provided with a first state and a second state, when the rotating air flow regulating structure is in the first state, the air inlet channel forms a cyclone channel; when the rotating air flow regulating structure is in the second state, the air inlet channel forms a straight air channel;

[0008] The fuel spray gun is mounted on the rear cover of the air inlet housing, and extends through the air inlet passage of the rotating airflow regulating structure to the burner nozzle, the air inlet end of the fuel spray gun is located outside the air inlet housing, and the nozzle end of the fuel spray gun is connected to the burner nozzle;

[0009] The protective air duct is installed at the rear cover of the air inlet housing and extends to the burner nozzle. The hydrogen and oxygen duct is sleeved in the protective air duct and extends to the burner nozzle.

[0010] In a preferred embodiment of the present invention, the fuel spray gun comprises a centrally located fuel nozzle and an atomizing gas nozzle, and the centrally located fuel nozzle and the atomizing gas nozzle are in the form of concentric sleeves and form an integral body.

[0011] In a preferred embodiment of the present invention, the hydrogen and oxygen gas conduit includes a hydrogen and oxygen gas ring pipe and a plurality of hydrogen and oxygen gas straight pipes. The hydrogen and oxygen gas interface is connected to the hydrogen and oxygen gas ring pipe inside the air inlet shell outside the air inlet shell, and then the hydrogen and oxygen gas are guided to the nozzle by the plurality of hydrogen and oxygen gas straight pipes.

[0012] In a preferred embodiment of the present invention, the combined injection port formed by the nozzle of the protective air duct and the nozzle of the hydrogen and oxygen duct forms an annular uniform distribution shape on the outer side of the burner nozzle, the hydrogen and oxygen nozzles are made at different angles, and the protective air injection port is made into a swirl shape.

[0013] In a preferred embodiment of the present invention, the position adjustment range of the air regulating plate is between 0°-180°, the percentage of the primary airflow and the secondary airflow obtained is between 5%-95%, and by adjusting the state of the rotating airflow regulating structure, the primary airflow can be converted between direct current wind, swirl wind and direct current swirl mixed wind.

[0014] In a preferred embodiment of the present invention, a front partition and a rear partition are provided in the internal cavity of the air inlet shell, the front partition is located at the air outlet of the air inlet shell, and the rear partition is located at the air inlet of the air inlet shell, and the rear partition divides the internal cavity into a first cavity through which the primary airflow passes and a second cavity through which the secondary airflow passes.

[0015] In a preferred embodiment of the present invention, the secondary airflow channel includes a plurality of secondary airflow ducts, the front end of the secondary airflow duct is installed on the front baffle and is connected to the nozzle of the burner nozzle; the rear end of the secondary airflow duct is installed on the rear baffle and is connected to the second cavity through which the secondary airflow passes, the second cavity, the secondary airflow duct and the nozzle form the secondary airflow channel, and a secondary airflow nozzle is provided at the burner nozzle, and the secondary airflow nozzle is a nozzle hole at different angles or a nozzle hole composed of blades at a certain angle.

[0016] In a preferred embodiment of the present invention, the rotating airflow regulating structure includes an air guide pipe, a cyclone, a vortex regulator and a regulator;

[0017] The air guide pipe is located at the outlet of the nozzle;

[0018] The vortex adjuster and the cyclone are located in the internal cavity. The vortex adjuster includes a rear sleeve and a vortex adjusting tube. The rear sleeve is installed at the tail end of the internal cavity. The vortex adjusting tube includes a slotted section and a sealing section. The slotted section of the vortex adjusting tube is sleeve-connected with the rear sleeve.

[0019] One end of the cyclone is connected to the sealing section of the swirl regulating tube, and the other end of the cyclone is connected to the air guide tube;

[0020] The regulator is connected to the swivel tube, and the regulator adjusts the forward and backward movement of the swivel tube between the rear sleeve and the air guide tube;

[0021] When the cyclone regulating tube is located at the rear end, the cyclone device is connected with the air guide tube to form a cyclone channel;

[0022] When the swirl regulating tube is located at the front end, the swirl regulating tube is connected with the air guide tube to form a straight air channel.

[0023] In a preferred embodiment of the present invention, the fuel of the fuel spray gun located at the coaxial center is liquid fuel, gas fuel, powdered solid fuel or a mixture of multiple fuels.

[0024] In a preferred embodiment of the present invention, the fuel spray gun also includes a fuel flow adjustment rod and a spray gun telescopic adjustment device. The fuel flow adjustment rod is located in the channel of the fuel nozzle at the center position and is used to adjust the area of ​​the fuel nozzle cross-section. The spray gun telescopic adjustment device is used to adjust the fuel injection position.

[0025] In a preferred embodiment of the present invention, the fuel spray gun also includes an ignition gas nozzle, an ignition air nozzle, and an ignition detection electrode at an outer position, the fuel nozzle at the center position, the atomizing gas nozzle, the ignition gas nozzle at the outer position, and the ignition air nozzle are in the form of concentric sleeves and form a whole, the nozzle of the ignition gas nozzle and the nozzle of the ignition air nozzle are connected to a premixing chamber, the premixing chamber is connected to an ignition burner combustion chamber, the ignition burner combustion chamber is connected to an ignition flame nozzle, the ignition detection electrode is located in the channel of the combustion-supporting air nozzle, and the ignition end of the ignition detection electrode is located in the ignition burner combustion chamber.

[0026] In a preferred embodiment of the present invention, the internal cavity of the air inlet shell is divided into an independent air chamber by a rear partition, and the central air outside the air inlet shell is connected to the independent air chamber inside the air inlet shell and then divided into two parts, one part of which enters the protective air duct to surround the hydrogen and oxygen duct until the protective nozzle, and the other part enters the channel of the ignition air nozzle and enters the premixing chamber as the ignition air of the ignition gas burner.

[0027] In a preferred embodiment of the present invention, the gas of the ignition gas nozzle is turned off after the main fuel of the fuel spray gun is stably burned, while the ignition air of the ignition air nozzle is kept on. As a part of the combustion-supporting air, another function of the ignition air is to effectively isolate the influence of the high-temperature combustion-supporting air on the fuel spray gun.

[0028] In a preferred embodiment of the present invention, the flame ignition signal of the ignition gas nozzle is monitored by the ion signal of the ignition electrode or by installing UV in the internal observation port.

[0029] The beneficial effects of the present invention are as follows: the low NOx burner of the present invention, on the one hand, utilizes the high-speed ejection of hydrogen and oxygen gas greater than 200m / s and the protective air to form an ejection port at the outer part of the burner nozzle, forms jets at different angles to roll up the smoke in the furnace, utilizes the catalytic characteristics of hydrogen and oxygen gas to improve the burnout rate, and reduces the carbon black in the smoke. At the same time, a graded air distribution device is utilized to control the combustion speed of the fuel through graded air distribution, reduce the local high temperature of the flame, and utilize a rotating air flow adjustment structure to achieve the change between the length of the combustion flame under the condition of constant combustion power, so that the combustion flame shape and combustion process of the fuel are controlled, thereby achieving low NOx emissions of different fuels. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a three-dimensional structural schematic diagram of a preferred embodiment of the low NOx burner of the present invention;

[0031] Figure 2 yes Figure 1 A schematic cross-sectional view of a low NOx burner is shown;

[0032] Figure 3 yes Figure 2 BB cross-sectional structure diagram;

[0033] Figure 4 yes Figure 2 Schematic diagram of CC cross-sectional structure;

[0034] Figure 5 yes Figure 2 EE cross-sectional structure diagram;

[0035] Figure 6 yes Figure 5 Schematic diagram of the left view structure;

[0036] Figure 7 yes Figure 5 A schematic diagram of the structure of the right view;

[0037] Figure 8 It is a three-dimensional structural schematic diagram of a preferred embodiment of the graded air distribution device used in the low NOx burner of the present invention;

[0038] Fig. 9 yes Figure 8 The rear view structural diagram of the graded air distribution device shown;

[0039] Fig.10 yes Fig. 9 AA cross-sectional structural diagram;

[0040] Fig.11 yes Fig.10 EE cross-sectional structure diagram;

[0041] Fig.12 yes Fig.10 A schematic diagram of a local enlarged structure;

[0042] Fig.13 yes Figure 8 A schematic cross-sectional view of the structure of the first working state of the graded air distribution device shown;

[0043] Fig.14 yes Figure 8 A cross-sectional structural schematic diagram of the second working state of the graded air distribution device shown;

[0044] Fig.15 yes Figure 8 A cross-sectional structural schematic diagram of the third working state of the graded air distribution device shown;

[0045] Fig.16 yes Figure 8 A schematic cross-sectional view of the structure of the graded air distribution device in a fourth working state;

[0046] Fig.17 yes Figure 8 A cross-sectional structural schematic diagram of the fifth working state of the graded air distribution device shown;

[0047] The markings of the components in the accompanying drawings are as follows: 100-air inlet housing, 140-rear cover, 141-protective air interface, 142-internal observation monitoring hole, 143-external observation hole, 144-hydrogen and oxygen interface, 200-fuel spray gun, 210-fuel nozzle, 220-atomizing gas nozzle, 221-fuel flow adjustment rod, 222-spray gun telescopic adjustment device, 230-ignition gas nozzle, 240-ignition air nozzle, 241-ignition air inlet, 250-ignition detection electrode, 260-premixing chamber, 270-ignition burner combustion chamber, 280-ignition flame nozzle, 290-central fuel nozzle, 300-burner nozzle, 400-grading Air distribution device, 421-air adjustment plate, 422-air adjustment indication handle, 431-primary air flow nozzle, 432-secondary air flow nozzle, 451-secondary air flow duct, 460-rotating air flow adjustment structure, 461-air guide pipe, 463-blade, 464-cyclone rear cover, 465-rotating adjustment pipe, 466-connecting rod, 468-rear sleeve, 469-adjustment structure, 4691-outer spiral pipe 4692-inner spiral pipe, 4693-handle, 471-front partition, 472-rear partition, 500-protective air guide pipe, 510-protective air nozzle, 600-hydrogen and oxygen air guide pipe, 610-hydrogen and oxygen nozzle, 700-furnace body mounting plate. DETAILED DESCRIPTION

[0048] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0049] See also Figure 1-Figure 17 It should be noted that the diagrams provided in this embodiment illustrate the basic concept of the present invention, and the components of the present invention in the diagrams are drawn according to the number, shape and size of components in actual implementation. The embodiments of the present invention include:

[0050] Combination Figures 1 to 7 As shown, a low NOx burner includes: an air inlet housing 100, a fuel spray gun 200, a burner nozzle 300, a graded air distribution device 400, a protective air guide pipe 500 and a hydrogen and oxygen guide pipe 600.

[0051] The air inlet housing 100 includes an internal cavity, an air inlet, an air outlet and a rear cover 140. As shown in the structure of this embodiment, the air inlet housing 100 is L-shaped, and the air inlet and the air outlet are respectively at the two ends of the L. The rear cover 140 and the air outlet form a cylindrical cavity space. Figure 6 As shown, the rear cover is provided with a protective air interface 141, a hydrogen and oxygen interface 144, a fuel spray gun 200 mounting hole, an internal observation monitoring hole 142 and an external observation hole 143.

[0052] The burner nozzle 300 is installed at the air outlet. In this embodiment, a furnace body mounting plate 700 is installed at the connection between the burner nozzle 300 and the air outlet. The furnace body mounting plate 700 is provided with a plurality of mounting holes. The burner is mounted on the outer wall of the furnace body through the mounting holes through bolts and other connecting parts. The burner nozzle 300 extends into the furnace. Figure 2 and Figure 7 As shown, the burner nozzle 300 is provided with a central fuel nozzle 290, an ignition flame nozzle 280, a primary airflow nozzle 431, a secondary airflow nozzle 432, a hydrogen-oxygen nozzle 610 and a protective air nozzle 510 in sequence from the center to the periphery. The hydrogen-oxygen nozzle 610 is located at the axis of the protective air nozzle 510, and the two are combined into a combined nozzle. A plurality of secondary airflow nozzles 432 and a plurality of combined nozzles are arranged at intervals around the outer circle of the burner nozzle 300. The secondary airflow nozzles 432 entering in stages can be made into spray holes of different angles, or can be made into blades of a certain angle, and the injection ports composed of the hydrogen-oxygen and protective air are evenly arranged and comprehensively applied at the outer part of the burner nozzle 300, further improving the flue gas circulation effect in the furnace, and meeting the combustion requirements of different fuel characteristics.

[0053] The graded air distribution device 400 includes an air regulating device, a primary air flow channel, a secondary air flow channel and a rotating air flow regulating structure; the air regulating device is installed at the air inlet of the air inlet housing 100; the primary air flow channel and the secondary air flow channel are located in the internal cavity of the air inlet housing 100, and the primary air flow channel and the secondary air flow channel are relatively independent; the air regulating device includes an air regulating plate, which can rotate and stay in at least two extreme positions. When the air regulating plate is in the middle position, the inlet of the primary air flow channel and the inlet of the secondary air flow channel are opened at the same time; when the air regulating plate is in the first extreme position, the inlet of the secondary air flow channel is closed, and the inlet of the primary air flow channel is opened; when the air regulating plate is in the second extreme position, the inlet of the primary air flow channel is closed, and the inlet of the secondary air flow channel is opened; the rotating air flow regulating structure includes an air inlet channel, which is connected to the first air flow channel, and the rotating air flow regulating structure is provided with a first state and a second state. When the rotating air flow regulating structure is in the first state, the air inlet channel forms a cyclone channel; when the rotating air flow regulating structure is in the second state, the air inlet channel forms a straight air channel.

[0054] The rotating airflow regulating structure can change the swirl intensity of the airflow at the primary airflow nozzle 431, forming a conversion from direct current to strong swirl, and the flame length and diameter can be changed without changing the combustion power, which is suitable for the heating requirements of different furnace volumes.

[0055] The graded air distribution device 400 allows the combustion air to enter the air housing in grades, and the air adjustment plate position can be adjusted arbitrarily between 0°-180° by controlling the air adjustment indicator handle outside the air housing, so that the primary airflow and the secondary airflow can be adjusted between 5%-95%, so that the mixing speed of air and fuel can be controlled, graded combustion can be achieved, the high temperature zone of combustion can be controlled, and the generation of thermal NOx can be reduced. When the air flow and pressure of the main pipe allow, the total flow of the combustion air of the graded air distribution device 400 is close to twice that of the primary airflow or the secondary airflow, so that the burner can obtain a larger adjustment ratio.

[0056] The fuel spray gun 200 is installed on the rear cover of the air inlet housing 100, and extends through the air inlet channel of the rotating airflow regulating structure to the burner nozzle 300. The air inlet end of the fuel spray gun 200 is located outside the air inlet housing 100, and the nozzle end of the fuel spray gun 200 is connected to the burner nozzle 300. The fuel spray gun 200 also includes a fuel nozzle 210 at a central position, an atomizing gas nozzle 220, an ignition gas nozzle 230 at an outer position, an ignition air nozzle 240, and an ignition detection electrode 250. The fuel nozzle 210 at the central position, the atomizing gas nozzle 220, the ignition gas nozzle 230 at an outer position, and the ignition air nozzle 240 are in the form of concentric sleeves and form a whole. The nozzle of the ignition gas nozzle 230 and the nozzle of the ignition air nozzle 240 are connected to the premixing chamber 260, and the premixing chamber 260 is connected to the ignition burner combustion chamber 270, and the ignition burner combustion chamber 270 is connected to the ignition flame nozzle 280. The ignition detection electrode 250 is located in the channel of the combustion-supporting air nozzle, and the ignition end of the ignition detection electrode 250 is located in the ignition burner combustion chamber 270.

[0057] The coaxial periphery of the fuel spray gun 200 is equipped with a gas burner capable of independent ignition and combustion. The ignition gas and ignition air are mixed in the premixing chamber 260 and enter the combustion chamber to be ignited by the electrode. The ignition and combustion power can be selected according to the fuel characteristics. An annular flame is formed on the periphery of the fuel spray gun 200 to form an ignition source. The fuel from the fuel spray gun 200 can be effectively ignited. The gas of the ignition burner can be turned off after the main fuel of the fuel spray gun 200 is stably burned, while the ignition air is always on. As a part of the combustion-supporting air, the ignition air has another function of effectively isolating the influence of the high-temperature combustion-supporting air on the fuel spray gun 200. The flame ignition signal of the ignition burner can be the ion signal of the ignition electrode, or UV monitoring can be installed at the internal observation hole.

[0058] The fuel of the fuel spray gun 200 located at the coaxial center is liquid fuel, gas fuel, powdered solid fuel or a mixture of multiple fuels. The fuel spray gun 200 also includes a fuel flow adjustment rod 221 and a spray gun telescopic adjustment device 222. The fuel flow adjustment rod is located in the channel of the fuel nozzle at the center position and is used to adjust the area of ​​the fuel nozzle cross section. The spray gun telescopic adjustment device is used to adjust the fuel injection position. The fuel and the oxidant can obtain a better mixing point, which is conducive to the combustion of different fuels.

[0059] The protective air duct 500 is installed at the rear cover of the air inlet housing 100 and extends to the burner nozzle 300. The hydrogen-oxygen air duct 600 is sleeved in the protective air duct 500 and extends to the burner nozzle 300. The hydrogen-oxygen conduit includes a hydrogen-oxygen ring pipe and a plurality of hydrogen-oxygen straight pipes. The hydrogen-oxygen interface 144 is connected to the hydrogen-oxygen ring pipe in the air inlet housing 100 outside the air inlet housing 100, and then the hydrogen-oxygen straight pipes guide the hydrogen-oxygen to the nozzle. The protective air nozzle 510 of the protective air conduit and the hydrogen-oxygen nozzle 610 of the hydrogen-oxygen conduit form a combined injection port, which is uniformly distributed in an annular shape at the outer part of the burner nozzle 300. The hydrogen-oxygen nozzle 610 is made at different angles, and the protective air injection port is made into a swirl shape to expand the area of ​​hydrogen-oxygen injection, and also protect the hydrogen-oxygen nozzle 610 on the inside. At the same time, the protective air can isolate the influence of the high temperature of the combustion-supporting air on the hydrogen-oxygen conduit and the nozzle. The injection nozzle composed of hydrogen and oxygen and protective air utilizes the high-speed injection of hydrogen and oxygen greater than 200m / s to form jets of different angles at the outer side of the burner nozzle 300 in the furnace to entrain the flame gas in the furnace, so that the flame gas circulates and diffuses in the furnace to form a low-oxygen combustion atmosphere, and utilizes the catalytic properties of hydrogen and oxygen to improve the burnout rate, reduce the excess air coefficient, reduce the carbon black in the flue gas, save fuel, and achieve low NOx emissions.

[0060] The internal cavity of the air inlet housing 100 is divided into an independent air chamber by a rear partition. The protective air outside the air inlet housing 100 is connected to the independent air chamber inside the air inlet housing 100 and is divided into two parts. One part enters the protective air duct to surround the hydrogen and oxygen duct until the protective nozzle, and the other part enters the channel of the ignition air nozzle 240 and enters the premixing chamber 260 as the ignition air of the ignition gas burner.

[0061] Combination Figures 8 to 17 The graded air distribution device 400 includes: an air inlet housing 100 , an air regulating device, a nozzle (ie, a burner nozzle 300 ), a primary air flow channel, a secondary air flow channel and a rotating air flow regulating structure 460 .

[0062] The air inlet housing 100 includes an internal cavity, an air inlet and an air outlet. In this embodiment, the air inlet housing 100 is L-shaped, and the air inlet and the air outlet are located at two ends of the L-shape.

[0063] The burner nozzle 300 is installed at the air outlet of the air inlet housing 100, and the tail end of the burner nozzle 300 is connected to the air outlet of the air inlet housing 100. In this embodiment, the tail end of the burner nozzle 300 is detachably connected and fixed to the air outlet of the air inlet housing 100 by bolts or other connecting parts, and can also be fixed in other ways. A primary airflow nozzle 431 and a secondary airflow nozzle 432 are provided at the outlet of the burner nozzle 300. The secondary airflow nozzle 432 is a nozzle with different angles or a nozzle composed of blades at a certain angle, which can be replaced according to different combustion characteristics.

[0064] The air regulating device is installed at the air inlet of the air inlet housing 100. The air regulating device includes an air regulating plate 421 and an air regulating indicating handle 422 which are connected to each other. The air regulating plate 421 is installed in the air inlet housing 100, and the air regulating indicating handle 422 is installed outside the air inlet housing 100. The angle position of the air regulating plate 421 can be adjusted by twisting the air regulating indicating handle 422. The air regulating plate 421 can rotate and can stay in at least two extreme positions: a first extreme position and a second extreme position. When the air regulating plate 421 is in the middle position, the inlet of the primary air flow channel and the inlet of the secondary air flow channel are opened at the same time; when the air regulating plate 421 is in the first extreme position, the inlet of the secondary air flow channel is closed, and the inlet of the primary air flow channel is opened; when the air regulating plate 421 is in the second extreme position, the inlet of the primary air flow channel is closed, and the outlet of the secondary air flow channel is opened.

[0065] The primary airflow channel and the secondary airflow channel are located in the internal cavity of the air inlet housing 100, the primary airflow channel and the secondary airflow channel are relatively independent, the inlet of the primary airflow channel and the inlet of the secondary airflow channel are located at the air inlet of the air inlet housing 100, and the outlet of the primary airflow channel and the outlet of the secondary airflow channel are located at the air outlet of the air inlet housing 100. Specifically, a front baffle 471 and a rear baffle 472 are provided in the internal cavity of the air inlet housing 100, the front baffle 471 is located at the air outlet of the air inlet housing 100, the rear baffle 472 is located at the air inlet of the air inlet housing 100, and the rear baffle 472 divides the internal cavity into a first cavity through which the primary airflow passes and a second cavity through which the secondary airflow passes. The secondary airflow channel includes a plurality of secondary airflow ducts 451, the front end of which is mounted on the front baffle 471 and communicated with the burner nozzle 300; the rear end of which is mounted on the rear baffle 472 and communicated with the second cavity through which the secondary airflow passes, and the second cavity, the secondary airflow duct 451 and the burner nozzle 300 form the secondary airflow channel. The first cavity through which the primary airflow passes is the primary airflow channel.

[0066] The rotating airflow regulating structure 460 includes an air inlet channel, which is connected to the first airflow channel. The rotating airflow regulating structure 460 is provided with a first state and a second state. When the rotating airflow regulating structure 460 is in the first state, the air inlet channel forms a cyclone channel; when the rotating airflow regulating structure 460 is in the second state, the air inlet channel forms a straight air channel.

[0067] Specifically, the rotating airflow regulating structure 460 includes an air guide pipe 461, a cyclone, a swirl regulator and a regulator; the air guide pipe 461 is located at the outlet of the burner nozzle 300; the swirl regulator and the cyclone are located in the internal cavity, the swirl regulator includes a rear sleeve 468 and a swirl regulating pipe 465, the rear sleeve 468 is installed at the tail end of the internal cavity, the swirl regulating pipe 465 includes a slotted section and a sealing section, the slotted section of the swirl regulating pipe 465 is sleeved and connected to the rear sleeve 468; the cyclone One end of the regulator is connected to the sealing section of the swirl regulating tube 465, and the other end of the cyclone is connected to the air guide tube 461; the regulator is connected to the swirl regulating tube 465, and the regulator regulates the forward and backward movement of the swirl regulating tube 465 between the rear sleeve 468 and the air guide tube 461; when the swirl regulating tube 650 is located at the rear end, the cyclone is connected to the air guide tube 461 to form a cyclone channel; when the swirl regulating tube 650 is located at the front end, the swirl regulating tube is connected to the air guide tube 461 to form a straight wind channel.

[0068] The cyclone includes a cyclone front cover, a cyclone rear cover 464 and blades 463. The blades 463 are installed between the cyclone front cover and the cyclone rear cover 464. The sealing section of the cyclone regulating tube 465 is connected to the cyclone rear cover 464. The air guide tube 461 is connected to the cyclone front cover 620. In this embodiment, the cyclone front cover is a part of the front partition 471. Fig.10 As an example, the blade 463 is a single body, with 6 blades evenly distributed and installed in a positive direction, and the airflow is guided by the blade 463 to form a right-handed rotating wind. The inner diameter of the cyclone rear cover 464 is consistent with the inner edge contour of the blade 463, and is flexibly matched with the outer diameter of the sealing section of the swirl regulating tube 465.

[0069] The vortex adjuster is located in the internal cavity, one end of the vortex adjuster is connected to the cyclone, and the other end is connected to the rear end of the air inlet housing 100. The vortex adjuster includes a vortex adjusting tube 465 and a rear sleeve 468, the rear sleeve 468 is installed at the rear end of the internal cavity, and the tail end of the rear sleeve 468 is closed. The vortex adjusting tube 465 includes a slotted section and a sealing section, and the slotted section of the vortex adjusting tube 465 is sleeve-connected with the rear sleeve 468; further preferably, the inner diameter of the rear sleeve 468 and the slotted section of the vortex adjusting tube 465 are matched or the outer diameter is movably matched. The sealing section of the vortex adjusting tube 465 is connected to the rear cover 4 of the cyclone, and the air guide pipe 461 is connected to the front cover of the cyclone. As an example, the sealing section of the vortex adjusting tube 465 is a smooth tube, and the slotted section of the vortex adjusting tube 465 is a pipe with 6 evenly distributed slots on the surface. As an example, the slotted equivalent cross-section of the slotted section of the swivel adjusting tube 465 is consistent with the equivalent cross-section formed by the blade 463, and both are in the shape of a long slot. The regulator adjusts the swivel adjusting tube 465 to be able to move forward and backward between the rear sleeve 468 and the air guide tube 461. In order to limit the displacement distance of the swivel adjusting tube 465, the outer wall of the swivel adjusting tube 465 in this embodiment has a protruding structure, and is located at the connection between the sealing section and the slotted section of the swivel adjusting tube 465. Fig.10 As shown, when the swirl regulating tube 465 is located at the front end, the protruding structure contacts the cyclone rear cover 464, limiting the swirl regulating tube 465 from further moving forward.

[0070] The regulator includes an adjustment structure 469 and a connecting rod 466. The adjustment structure 469 is installed on the outside of the air inlet housing 100. One end of the connecting rod 466 is connected to the adjustment structure 469, and the other end is connected to the rotary adjustment tube 465. In order to facilitate the connection with the connecting rod 466, the outer wall of the rotary adjustment tube 465 has a protruding ear-shaped connection structure, and the connecting rod 466 is connected to the ear-shaped connection structure. The ear-shaped connection structure is located at the connection between the sealing section and the slotted section of the rotary adjustment tube 465. The adjustment structure 469 is a threaded rotation conversion linear pulling method, located on the outside of the air inlet housing 100 and connected to the connecting rod 466. Specifically, the adjustment structure 469 includes an outer spiral tube 4691 and an inner spiral tube 4692, the front end of the outer spiral tube 4691 is fixed to the outside of the air inlet housing 100, the front end of the inner spiral tube 4692 is connected to the rear end of the outer spiral tube 4691 by threads, the connecting rod 466 is sleeved in the outer spiral tube 4691 and the inner spiral tube 4692, the front end of the connecting rod 466 is connected to the adjusting tube 465, and the rear end of the connecting rod 466 is connected to the rear end of the inner spiral tube 4692. For the convenience of adjustment, the rear end of the inner spiral tube 4692 is provided with a handle 4693 structure.

[0071] The operation process of the adjustment structure 469 shown in this embodiment is as follows: by rotating the handle 4693 on the outside of the adjustment structure 469, the connecting rod 466 can be driven to move forward or backward, thereby linking the adjustment tube 465 to move forward and backward, so that the airflow can be converted between the air inlet groove formed by the tangential blades and the straight groove at the rear end of the adjustment tube.

[0072] The action process of the rotating airflow regulating structure 460 shown in this embodiment is as follows: Fig.10 and Fig.13 As shown, when the swirl regulating tube 650 is located at the rear end, the cyclone is connected to the air guide pipe 461 to form a cyclone channel. Specifically, when the swirl regulating tube 650 is located at the rear end, the slotted section of the swirl regulating tube 650 is located at the rear sleeve 468, the straight slot of the slotted section is closed by the rear sleeve 468, and the air inlet slot formed by the tangential blades of the cyclone is opened. In this way, the airflow enters the primary airflow channel from the air inlet of the air inlet shell 100, then flows through the air inlet slot formed by the tangential blades of the cyclone to form a rotating airflow, and finally is discharged from the air guide pipe 461. Combined with Fig.14As shown, when the swirl regulating tube is located at the front end, the swirl regulating tube is connected with the air guide tube to form a straight air channel. Specifically, when the swirl regulating tube 650 is located at the front end, the slotted section of the swirl regulating tube 650 leaves the rear sleeve 468, the straight slot of the slotted section is opened, and the sealing section of the swirl regulating tube 650 is located in the cyclone, so the air inlet slot formed by the tangential blades of the cyclone is closed. In this way, the airflow enters the primary airflow channel from the air inlet of the air inlet housing 100, and then flows through the straight slot of the slotted section of the swirl regulating tube 650 and enters the sealing section of the swirl regulating tube 650. An axial airflow is formed and finally discharged from the air guide tube 461.

[0073] The rear end of the air guide pipe 461 is installed on the front baffle 471, and the front end of the air guide pipe 461 is installed at the air outlet of the burner nozzle 300 and extends outside the air outlet of the burner nozzle 300. The air guide pipe 461 is located at the coaxial center position of the burner nozzle 300, and a plurality of secondary air flow ducts 451 are installed around the air guide pipe 461.

[0074] The angle position of the air regulating plate 421 of the graded air distribution device 400 can be adjusted arbitrarily between 0°-180°, and the primary airflow and the secondary airflow can be adjusted between 5%-95%. At the same time, the primary airflow is adjustable between direct air and swirl air. Thus, the ratio and rotation intensity of the primary and secondary air ejected at the nozzle can be changed, and flames of different shapes can be obtained when used on the burner. The primary airflow and the secondary airflow can flow into a maximum of 95% of the combustion air, and the air regulating plate 421 is located in the middle state. When the air flow and pressure of the main pipe allow, the total flow of the combustion air is close to twice that of the primary airflow or the secondary airflow, so that the burner can obtain a larger adjustment ratio.

[0075] Combination Fig.13 As shown, the first working state of the graded air distribution device 400 is: the rotating airflow regulating structure 460 is adjusted to the first state, that is, the swirl regulating tube 650 is located at the rear end, the air inlet channel is a cyclone channel, the air regulating plate 421 is adjusted to the first extreme position, the secondary airflow channel is closed, and the primary airflow forms a pressure chamber between the front baffle 471 and the rear baffle 472. 95% of the combustion-supporting air blown into the air inlet shell 100 forms a rotating airflow after passing through the cyclone channel, and a tangential swirl wind, that is, a radial diffusion airflow, is formed at the primary airflow nozzle 431. The secondary airflow located on the outside is very small and is controlled at about 5%.

[0076] Combination Fig.14As shown, the second working state of the graded air distribution device 400 is: the rotating airflow regulating structure 460 is adjusted to the second state, that is, the swirl regulating tube 650 is located at the front end, the air inlet channel is a straight air channel, the air regulating plate 421 is adjusted to the first extreme position, the secondary airflow channel is closed, and the primary airflow forms a pressure chamber between the front partition 471 and the rear partition 472. 95% or more of the combustion-supporting air blown into the air inlet shell 100 passes through the cyclone channel to form axial wind, and axial direct current wind is formed at the primary airflow nozzle 431. The secondary airflow located on the outside is controlled at about 5%.

[0077] Combination Fig.15 As shown, the third working state of the graded air distribution device 400 is: adjust the air regulating plate 421 to the second extreme position, close the primary air flow channel, and the secondary air flow forms a pressure chamber in front of the secondary air flow nozzle 432 through the secondary air flow duct 451, and 95% or more of the combustion-supporting air blown into the air inlet shell 100 forms a diffused airflow at the secondary air flow nozzle 432, and the primary airflow on the inner side is controlled at about 5%.

[0078] Combination Fig.16 As shown, the fourth working state of the graded air distribution device 400 is: the air regulating plate 421 is adjusted to the middle position, and the combustion-supporting air blown into the air inlet housing 100 forms 50% primary airflow and 50% secondary airflow. The swirl airflow regulating structure 460 is adjusted to the swirl position, and 50% of the primary airflow is swirl wind.

[0079] Combination Fig.17 As shown, the fifth working state of the graded air distribution device 400 is: the air regulating plate 421 is adjusted to the middle position, and the combustion-supporting air blown into the air inlet housing 100 forms 50% primary airflow and 50% secondary airflow. A rotating airflow regulating structure 460 is adjusted to the DC position, and 50% of the primary airflow is DC air.

[0080] The other working states of the graded air distribution device 400 are not listed one by one. The graded air distribution device 400 can change the ratio and rotation intensity of the primary and secondary air ejections at the nozzle through the above-mentioned rotating airflow adjustment structure 469 and the air adjustment plate position. When used on the burner, flames of different shapes can be obtained, which can be suitable for different furnace shapes and improve the fuel mixing effect. The combustion speed of the fuel can be controlled by graded air distribution, thereby effectively reducing the emission of NOx in the flue gas.

[0081] The low NOx burner of the present invention integrates an injection port composed of hydrogen and oxygen and protective air, a graded air distribution device 400, a rotating airflow adjustment structure, a fuel spray gun 200 located at the coaxial center, and a burner located at the coaxial periphery of the fuel spray gun 200 that can form an independent ignition and combustion, so that the combustion effect of the burner is comprehensively improved, and the fuel cost advantage can be better reflected in the combustion of inferior fuels.

[0082] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "inside", "outside", "front", and back, etc., are based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the inventive product is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0083] Therefore, the present invention effectively overcomes various shortcomings in the prior art and has a high industrial utilization value. The above embodiments are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology can modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A low NOx burner, characterized in that: include: Air inlet housing, fuel spray gun, burner nozzle, graded air distribution device, protective air duct and hydrogen and oxygen duct, The air inlet housing comprises an internal cavity, an air inlet, an air outlet and a rear cover; The burner nozzle is connected to the air outlet; The graded air distribution device includes an air regulating device, a primary air flow channel, a secondary air flow channel and a rotating air flow regulating structure; the air regulating device is installed at the air inlet of the air inlet shell; the primary air flow channel and the secondary air flow channel are located in the internal cavity of the air inlet shell, and the primary air flow channel and the secondary air flow channel are relatively independent; the air regulating device includes an air regulating plate, the air regulating plate can rotate and stay in at least two extreme positions, when the air regulating plate is in the middle position, the inlet of the primary air flow channel and the inlet of the secondary air flow channel are opened at the same time; when the air regulating plate is in the first extreme position, the inlet of the secondary air flow channel is closed, and the inlet of the primary air flow channel is opened; when the air regulating plate is in the second extreme position, the inlet of the primary air flow channel is closed, and the inlet of the secondary air flow channel is opened; the rotating air flow regulating structure includes an air inlet channel, the air inlet channel is connected to the primary air flow channel, the rotating air flow regulating structure is provided with a first state and a second state, when the rotating air flow regulating structure is in the first state, the air inlet channel forms a cyclone channel; when the rotating air flow regulating structure is in the second state, the air inlet channel forms a straight air channel; The fuel spray gun is mounted on the rear cover of the air inlet housing, and extends through the air inlet passage of the rotating airflow regulating structure to the burner nozzle, the air inlet end of the fuel spray gun is located outside the air inlet housing, and the nozzle end of the fuel spray gun is connected to the burner nozzle; The protective air duct is installed at the rear cover of the air inlet housing and extends to the burner nozzle. The hydrogen and oxygen duct is sleeved in the protective air duct and extends to the burner nozzle. The fuel spray gun comprises a fuel nozzle and an atomizing gas nozzle at a central position, wherein the fuel nozzle and the atomizing gas nozzle at the central position are in the form of concentric sleeves and form an integral body; The fuel spray gun also includes an ignition gas nozzle, an ignition air nozzle, and an ignition detection electrode at an outer position. The fuel nozzle at the center position, the atomizing gas nozzle, the ignition gas nozzle at the outer position, and the ignition air nozzle are in the form of concentric sleeves and form a whole. The nozzle of the ignition gas nozzle and the nozzle of the ignition air nozzle are connected to a premixing chamber, the premixing chamber is connected to an ignition burner combustion chamber, the ignition burner combustion chamber is connected to an ignition flame nozzle, the ignition detection electrode is located in the channel of the combustion-supporting air nozzle, and the ignition end of the ignition detection electrode is located in the ignition burner combustion chamber. The inner cavity of the air inlet housing is divided into an independent air chamber by the rear partition plate. The central air outside the air inlet housing is connected to the independent air chamber inside the air inlet housing and then divided into two parts, one of which enters the protective air duct to surround the hydrogen and oxygen air duct until the protective nozzle, and the other enters the channel of the ignition air nozzle and enters the premixing chamber as the ignition air of the ignition gas burner; The gas of the ignition gas nozzle is turned off after the main fuel of the fuel spray gun is stably burned, while the ignition air of the ignition air nozzle is always turned on. As a part of the combustion-supporting air, another function of the ignition air is to effectively isolate the influence of high-temperature combustion-supporting air on the fuel spray gun.

2. The low NOx burner according to claim 1, characterized in that: The hydrogen and oxygen gas guide pipe includes a hydrogen and oxygen ring pipe and a plurality of hydrogen and oxygen straight pipes. The hydrogen and oxygen interface is connected to the hydrogen and oxygen ring pipe in the air inlet shell outside the air inlet shell, and then the hydrogen and oxygen are guided to the nozzle by the plurality of hydrogen and oxygen straight pipes.

3. The low NOx burner according to claim 1, characterized in that: The combined injection port formed by the nozzle of the protective air duct and the nozzle of the hydrogen and oxygen duct forms a uniformly distributed annular shape outside the burner nozzle. The hydrogen and oxygen nozzles are made at different angles, and the protective air injection port is made into a swirl shape.

4. The low NOx burner according to claim 1, characterized in that: The position adjustment range of the air regulating plate is between 0°-180°, and the percentage of the primary airflow to the secondary airflow obtained is between 5%-95%. By adjusting the state of the rotating airflow regulating structure, the primary airflow can be converted between direct current wind, swirl wind and direct current swirl mixed wind.

5. The low NOx burner according to claim 1, characterized in that: A front baffle and a rear baffle are provided in the internal cavity of the air inlet shell. The front baffle is located at the air outlet of the air inlet shell, and the rear baffle is located at the air inlet of the air inlet shell. The rear baffle divides the internal cavity into a first cavity through which the primary airflow passes and a second cavity through which the secondary airflow passes.

6. The low NOx burner according to claim 5, characterized in that: The secondary air flow channel includes a plurality of secondary air flow ducts, the front end of which is mounted on the front baffle and communicated with the nozzle of the burner nozzle; the rear end of which is mounted on the rear baffle and communicated with the second cavity through which the secondary air flow passes, the second cavity, the secondary air flow duct and the nozzle form the secondary air flow channel, and a secondary air flow nozzle is provided at the burner nozzle, and the secondary air flow nozzle is a nozzle hole at different angles or a nozzle hole composed of blades at a certain angle.

7. The low NOx burner according to claim 6, characterized in that: The rotating airflow regulating structure comprises an air guide pipe, a cyclone, a cyclone regulator and a regulator; The air guide pipe is located at the outlet of the nozzle; The vortex adjuster and the cyclone are located in the internal cavity. The vortex adjuster includes a rear sleeve and a vortex adjusting tube. The rear sleeve is installed at the tail end of the internal cavity. The vortex adjusting tube includes a slotted section and a sealing section. The slotted section of the vortex adjusting tube is sleeve-connected with the rear sleeve. One end of the cyclone is connected to the sealing section of the swirl regulating tube, and the other end of the cyclone is connected to the air guide tube; The regulator is connected to the rotatable tube, and the regulator regulates the forward and backward movement of the rotatable tube between the rear sleeve and the air guide tube; When the cyclone regulating tube is located at the rear end, the cyclone device is connected with the air guide tube to form a cyclone channel; When the swirl regulating tube is located at the front end, the swirl regulating tube is connected with the air guide tube to form a straight air channel.

8. The low NOx burner according to claim 1, characterized in that: The fuel of the fuel spray gun located at the coaxial center is liquid fuel, gas fuel, powdered solid fuel or a mixture of multiple fuels.

9. The low NOx burner according to claim 1, characterized in that: The fuel spray gun also includes a fuel flow adjustment rod and a spray gun telescopic adjustment device. The fuel flow adjustment rod is located in the channel of the fuel nozzle at the center position and is used to adjust the area of ​​the fuel nozzle cross-section. The spray gun telescopic adjustment device is used to adjust the fuel injection position.

10. The low NOx burner according to claim 1, characterized in that: The flame ignition signal of the ignition gas nozzle is monitored by the ion signal of the ignition electrode or by installing UV monitoring at the internal observation port.

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