Mixed fuel burner of industrial kiln

Abstract

The invention provides a mixed fuel burner for an industrial kiln. The mixed fuel burner comprises a burner body, a nozzle and a flame stabilizing disc which are arranged in sequence. The flame stabilizing disc is arranged at the end of the nozzle, a center through hole, a plurality of baffling holes and a plurality of peripheral holes are formed in the surface of the flame stabilizing disc, the center through hole is formed in the center of the flame stabilizing disc, the peripheral holes are formed in the periphery of the flame stabilizing disc, and the peripheral holes are evenly distributed in the circumferential direction of the flame stabilizing disc at intervals with the axis of the flame stabilizing disc as the center. And the baffling holes are formed between the central through hole and the peripheral hole, the multiple baffling holes are evenly distributed in the circumferential direction of the flame stabilizing disc at intervals with the axis of the flame stabilizing disc as the center, the side wall of each baffling hole is provided with a baffling plate, and the baffling plates are used for changing the flow direction of fuel oil sprayed out of the fuel oil spraying flow channel. According to the invention, the long injection distance of the methanol fuel can be ensured, and the methanol fuel and the fuel oil fuel can be efficiently mixed before entering a combustion area.

Description

Technical Field

[0001] The invention relates to a burner, in particular to an industrial kiln mixed fuel burner, and belongs to the technical field of industrial burners. Background Art

[0002] Existing industrial kilns generally use fossil fuels such as heavy oil as their energy source. This type of fuel has many problems, such as high carbon emissions, stricter policy restrictions, low energy utilization efficiency, and high risks of manual operation. Therefore, there is an urgent need to carry out clean transformation of industrial kiln combustion systems.

[0003] To achieve clean combustion, the use of green fuels, such as methanol, to replace traditional fossil energy has become a research hotspot. However, methanol, as an alternative fuel, also faces problems in combustion startup, stability, and heat transfer efficiency in practical applications.

[0004] Taking industrial kilns as an example, due to their high operating temperatures, radiation heat transfer plays a dominant role in their heat transfer process, accounting for approximately 70% to 80% of the heat transferred. However, the soot generated during the combustion process significantly reduces the flame's radiative heat transfer efficiency, thereby affecting the kiln's overall thermal efficiency. Traditional fuels produce soot due to partial incomplete combustion, which enhances radiative heat transfer. However, complete substitution with methanol results in complete combustion, producing only small molecules such as water and carbon dioxide, which have significantly weaker radiative capacity, resulting in insufficient radiative heat transfer efficiency of the combustion products. When radiative heat transfer efficiency decreases, the effective heat absorbed by the kiln also decreases. To meet the process's thermal energy requirements, fuel consumption must increase, resulting in reduced energy utilization and economic efficiency.

[0005] At the same time, methanol's latent heat of vaporization is much higher than that of traditional fuels. During the spray combustion process, methanol vaporizes and absorbs a significant amount of heat from the furnace, causing the mixture temperature to drop and the fuel ignition temperature to increase significantly, which in turn affects the initial combustion temperature and the overall efficiency of the kiln. Since methanol's low calorific value is only about half that of traditional fuels such as heavy oil and diesel, its fuel consumption increases significantly under conditions of the same power output. This also causes the theoretical combustion temperature in the furnace to drop, further affecting combustion stability and even causing significant difficulties during cold starts.

[0006] While ensuring stable methanol combustion, co-firing with traditional high-radiative fuels can optimize overall radiative heat transfer characteristics and improve kiln heat transfer efficiency and thermal utilization. This is an effective approach to addressing the shortcomings of methanol-only fuel. However, existing industrial multi-fuel burners typically employ direct fuel injection and mixing within the combustion chamber during co-firing. Due to their different physical properties, methanol and traditional high-radiative fuels are prone to inadequate mixing, fuel agglomeration, and localized excessive concentrations after exiting the nozzle. Premature and incomplete mixing of methanol fuel with air at the nozzle can lead to insufficient injection distance, resulting in the fuel dispersing into excessively fine droplets before reaching the combustion zone, making it difficult to effectively anchor the flame and stabilize the combustion core. Furthermore, fuel oil and methanol exhibit different ignition characteristics and combustion temperatures during injection and combustion. Improper premixing of the two fuels can result in a sudden temperature drop during the initial combustion phase or uneven fuel distribution within the combustion zone. This not only affects combustion efficiency but also poses emissions risks and safety risks. Summary of the Invention

[0007] Based on the above background, the purpose of the present invention is to provide an industrial kiln mixed fuel burner, which can achieve stratification and isolation of each fuel in the early stage of injection of mixed methanol fuel and fuel oil, extend the injection distance of methanol fuel, and enable each fuel and air to quickly reach an ideal pre-mixing ratio.

[0008] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0009] An industrial kiln mixed fuel burner comprises a burner body, a nozzle and a flame stabilizing disc arranged in sequence; the burner body is provided with a methanol fuel flow channel, a fuel oil fuel flow channel and an air flow channel in sequence from the center of the burner body to the periphery; the nozzle is provided with a methanol injection flow channel, a fuel oil injection flow channel and an air injection flow channel in sequence from the center of the nozzle to the periphery, the methanol injection flow channel is connected to the methanol fuel flow channel, the fuel oil injection flow channel is connected to the fuel oil fuel flow channel, and the air injection flow channel is connected to the air flow channel; the flame stabilizing disc is provided at the end of the nozzle, and the flame stabilizing disc is provided at the end of the nozzle. A central through hole, a plurality of deflection holes and a plurality of peripheral holes are provided on the surface, the central through hole is provided in the central part of the flame-stabilizing disc, the peripheral holes are provided in the peripheral part of the flame-stabilizing disc, and the plurality of peripheral holes are evenly distributed along the circumference of the flame-stabilizing disc with the axis of the flame-stabilizing disc as the center, the deflection hole is provided between the central through hole and the peripheral holes, and the plurality of deflection holes are evenly distributed along the circumference of the flame-stabilizing disc with the axis of the flame-stabilizing disc as the center, and a deflection plate is provided on the side wall of each deflection hole, and the deflection plate is used to change the flow direction of fuel ejected from the fuel injection channel.

[0010] This industrial furnace mixed fuel burner uses a nozzle with a concentric circle wrapped cross-section structure. The fuel in the middle layer isolates methanol and air, preventing violent mixing of methanol and air at the beginning of injection, thereby reducing uneven mixing caused by premature atomization. Under the wrapping effect of the fuel, methanol can maintain a long injection distance, which is conducive to forming an ideal combustion center. The air injection flow channel in the outermost layer can be introduced with oxygen-enriched air. After the fuel as the first stage fuel is burned, the oxygen-enriched air continues to support the combustion of methanol, forming a relay combustion mode. The flame-stabilizing disc at the end of the nozzle realizes controllable quantitative injection and preliminary mixing of the two fuels and air through the partitioning design of central through hole, deflection hole and peripheral hole. The deflector of the deflection hole changes the fuel flow direction, generating a strong turbulent effect, breaking up fuel agglomerations, and promoting sufficient mixing at the micro level. In this way, the two fuels quickly reach the ideal pre-mixed ratio after injection. The flame-stabilizing disc combined with the nozzle structure can ensure that the methanol fuel maintains a long injection distance and achieve efficient mixing before the methanol fuel and the fuel oil fuel enter the combustion zone.

[0011] Preferably, the flame-stabilizing dish is an inverted frustum structure that is through-through from top to bottom, and the outer wall contour line and the inner wall contour line are parallel to each other, and the top diameter of the flame-stabilizing dish is larger than the bottom diameter.

[0012] Preferably, the central through hole is directly connected to the methanol injection channel, the deflection hole is directly connected to the fuel injection channel, and the peripheral hole is directly connected to the air injection channel.

[0013] Preferably, the central through hole is arranged on the bottom surface of the flame stabilizing disk, the deflection holes and the peripheral holes are both arranged on the side conical surface of the flame stabilizing disk, the central through hole and the peripheral holes are both circular holes, and the deflection holes are triangular holes.

[0014] Preferably, the portion of the deflection hole adjacent to the peripheral hole is the pointed end of the triangular hole, and the portion of the deflection hole adjacent to the central through hole is the blunt end of the triangular hole.

[0015] Preferably, the shortest distance between the highest point of the pointed end of the deflection hole on the side conical surface of the flame stabilizing disk and the top of the side conical surface of the flame stabilizing disk is smaller than the shortest distance between the highest point of the peripheral hole on the side conical surface of the flame stabilizing disk and the top of the side conical surface of the flame stabilizing disk.

[0016] Preferably, the number of the deflection holes and the peripheral holes is the same, and each deflection hole is located between two adjacent peripheral holes.

[0017] Preferably, the baffle has the same shape as the baffle hole, and each baffle covers a portion of a baffle hole.

[0018] Preferably, an extension line of the deflector in the extending direction forms an angle with a tangent line of the inner wall of the flame-stabilizing disk at a portion where the deflector and the flame-stabilizing disk meet.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] The present invention provides an industrial kiln mixed fuel burner, and the nozzle adopts a wrapped structure, so that heavy oil forms a protective layer on the periphery, isolating methanol from air, ensuring that the methanol fuel can maintain a long injection distance, and avoiding excessive atomization due to premature mixing in the early stage of injection; the flame-stabilizing disc at the end of the nozzle realizes controllable quantitative injection and preliminary mixing of the two fuels and air, and the deflector of the deflection hole changes the flow direction of the fuel, produces a strong turbulent effect, breaks up fuel agglomerations, and promotes sufficient mixing at the microscopic level, so that the two fuels quickly reach an ideal pre-mixing ratio after injection; the flame-stabilizing disc cooperates with the nozzle structure to ensure that the methanol fuel maintains a long injection distance and achieves efficient mixing before the methanol fuel and the fuel oil enter the combustion zone. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0022] Figure 1 This is a schematic diagram of the overall external structure of a mixed fuel burner for an industrial kiln according to the present invention;

[0023] Figure 2 It is a schematic diagram of the internal partial structure of the burner body of the present invention;

[0024] Figure 3 It is a schematic diagram of the internal partial structure of the nozzle of the present invention;

[0025] Figure 4 It is a schematic diagram of the three-dimensional structure of the flame stabilizing dish in the present invention;

[0026] Figure 5 : is a schematic side view of the flame-stabilizing disk of the present invention, wherein a represents the top diameter of the flame-stabilizing disk, b represents the bottom diameter of the flame-stabilizing disk, c represents the shortest distance between the highest point of the sharp end of the deflection hole on the side conical surface of the flame-stabilizing disk and the top of the side conical surface of the flame-stabilizing disk, and d represents the shortest distance between the highest point of the peripheral hole on the side conical surface of the flame-stabilizing disk and the top of the side conical surface of the flame-stabilizing disk;

[0027] Figure 6The following are comparison diagrams of combustion flame simulations of the present invention. The left diagram is a simulation diagram of the combustion flame of an industrial furnace mixed fuel burner that does not utilize the combined structure of the nozzle and flame stabilizing disk of the present invention, while the right diagram is a simulation diagram of the combustion flame of an industrial furnace mixed fuel burner that utilizes the combined structure of the nozzle and flame stabilizing disk of the present invention.

[0028] In the figure: 1. Burner body; 2. Nozzle; 3. Flame stabilizing disc; 101. Methanol fuel flow channel; 102. Fuel oil fuel flow channel; 103. Air flow channel; 201. Methanol injection flow channel; 202. Fuel oil injection flow channel; 203. Air injection flow channel; 301. Center through hole; 302. Deflection hole; 303. Peripheral hole; 304. Deflector. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any form of modification and / or change made to the present invention will fall within the scope of protection of the present invention.

[0030] In the present invention, unless otherwise specified, all parts and percentages are by weight. The equipment and raw materials used are commercially available or commonly used in the art. The methods in the following embodiments, unless otherwise specified, are conventional methods in the art. The components or equipment in the following embodiments, unless otherwise specified, are all universal standard parts or components known to those skilled in the art. Their structures and principles are known to those skilled in the art through technical manuals or routine experimental methods.

[0031] The following detailed description of the embodiments of the present invention is made in conjunction with the accompanying drawings. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present invention. However, one or more embodiments may be implemented by those skilled in the art without these specific details.

[0032] like Figure 1-3 As shown, an embodiment of the present invention discloses an industrial kiln mixed fuel burner, comprising a burner body 1, a nozzle 2 and a flame stabilizing disc 3 arranged in sequence. The burner body 1 is provided with a methanol fuel flow channel 101, a fuel oil fuel flow channel 102 and an air flow channel 103 in sequence from the center portion of the burner body 1 to the peripheral portion. The nozzle 2 is provided with a methanol injection flow channel 201, a fuel oil injection flow channel 202 and an air injection flow channel 203 in sequence from the center portion of the nozzle 2 to the peripheral portion, the methanol injection flow channel 201 is connected to the methanol fuel flow channel 101, the fuel oil injection flow channel 202 is connected to the fuel oil fuel flow channel 102, and the air injection flow channel 203 is connected to the air flow channel 103. The flame stabilizing disc 3 is provided at the end of the nozzle 2, as shown Figure 4As shown, a central through hole 301, a plurality of deflection holes 302 and a plurality of peripheral holes 303 are provided on the surface of the flame-stabilizing disc 3. The central through hole 301 is provided in the central part of the flame-stabilizing disc 3, and the peripheral holes 303 are provided in the peripheral part of the flame-stabilizing disc 3, and the plurality of peripheral holes 303 are evenly distributed along the circumference of the flame-stabilizing disc 3 with the axis of the flame-stabilizing disc 3 as the center. The deflection holes 302 are provided between the central through hole 301 and the peripheral holes 303, and the plurality of deflection holes 302 are evenly distributed along the circumference of the flame-stabilizing disc 3 with the axis of the flame-stabilizing disc 3 as the center. A deflector 304 is provided on the side wall of each deflection hole 302, and the deflector 304 is used to change the flow direction of fuel ejected from the fuel injection channel 202.

[0033] Specifically, such as Figure 5 As shown, the flame-stabilizing disc 3 is a vertically through-hole inverted truncated cone structure, with its outer and inner wall contours parallel to each other. The top diameter a of the disc 3 is larger than the bottom diameter b. To ensure that each fuel maintains its predetermined supply path after entering the disc 3 and to reduce energy loss and unintended mixing during fuel flow, the central through-hole 301 is directly connected to the methanol injection channel 201, the deflecting holes 302 are directly connected to the fuel injection channel 202, and the peripheral holes 303 are directly connected to the air injection channel 203.

[0034] Specifically, a central through-hole 301 is provided on the bottom surface of the flame-stabilizing disc 3, while deflecting holes 302 and peripheral holes 303 are provided on the side conical surface of the disc 3. Both the central through-hole 301 and the peripheral holes 303 are circular, while the deflecting holes 302 are triangular. The circular central through-hole 301 on the bottom surface facilitates stable and uniform methanol ejection, while the circular peripheral holes 303 on the side conical surface ensure uniform air introduction. The triangular deflecting holes 302, due to their unique shape, facilitate directional disturbance of the fuel flow, thereby assisting the fuel in entering the mixing zone in a predetermined manner.

[0035] Specifically, the portion of the deflecting hole 302 adjacent to the peripheral hole 303 is the pointed end of the triangular hole, while the portion of the deflecting hole 302 adjacent to the central through hole 301 is the blunt end of the triangular hole. The shortest distance between the highest point on the conical surface of the flame-stabilizing disc 3 and the top of the conical surface is smaller than the shortest distance between the highest point on the conical surface of the peripheral hole 303 and the top of the conical surface.

[0036] Specifically, the number of deflection holes 302 and peripheral holes 303 is the same, and each deflection hole 302 is located between two adjacent peripheral holes 303. This balanced arrangement ensures uniform supply of fuel fluid in all areas of the flame stabilization disk 3, thereby achieving consistent disturbance and mixing effects for the fuel and air when entering the premixing zone.

[0037] Specifically, the baffles 304 have the same shape as the baffle holes 302, and each baffle 304 covers a portion of a baffle hole 302. The extension of the baffle 304 forms an angle with a tangent line to the inner wall of the flame-stabilizing disc 3 at the junction of the baffle 304 and the disc 3. This helps guide the fuel flow in a predetermined direction.

[0038] This industrial kiln mixed-fuel burner utilizes a nozzle 2 with a concentric, wrapped cross-section. The fuel in the middle layer isolates the methanol and air, preventing intense mixing of the two during the initial injection phase. This reduces uneven mixing caused by premature atomization. The fuel's wrapping effect allows the methanol to maintain a long injection distance, facilitating the formation of an ideal combustion center. The outermost air injection channel 203 allows oxygen-enriched air to flow in. After the fuel, the primary fuel, is burned, the oxygen-enriched air continues to support the methanol's combustion, creating a relay combustion mode. The flame-stabilizing disc 3 at the end of the nozzle 2 realizes controllable quantitative injection and preliminary mixing of the two fuels and air through the partition design of the central through hole 301, the deflection hole 302 and the peripheral hole 303. The deflector 304 of the deflection hole 302 changes the flow direction of the fuel, produces a strong turbulent effect, breaks up the fuel agglomeration, and promotes sufficient mixing at the microscopic level. In this way, the two fuels quickly reach the ideal pre-mixing ratio after being ejected. The flame-stabilizing disc 3 cooperates with the structure of the nozzle 2 to ensure that the methanol fuel maintains a longer injection distance and achieves efficient mixing before the methanol fuel and the fuel oil enter the combustion zone.

[0039] This embodiment simulates the combustion of the combined structure of the nozzle 2 and the flame stabilizing disk 3 before and after the application of the industrial furnace mixed fuel burner. Figure 6 The combustion flame simulation comparison diagram shows that the industrial furnace mixed fuel burner with the combined structure of nozzle 2 and flame stabilizing disk 3 has a more uniform and lower temperature distribution at the short distance from the flame outlet (within the box in the figure), which helps reduce NOx generation and carbon dioxide emissions while also saving fuel. This shows that the combined design of the nozzle and flame stabilizing disk achieves stratified isolation and efficient premixing of the fuel, not only enabling methanol to maintain a longer injection distance, thereby ensuring flame anchoring stability, but also reducing the formation of local high-temperature areas before the fuel enters the combustion zone.

[0040] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from the principles of the present invention, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. An industrial kiln mixed fuel burner, characterized by: The industrial kiln mixed fuel burner comprises a burner body (1), a nozzle (2) and a flame stabilizing disc (3) which are arranged in sequence; the burner body (1) is provided with a methanol fuel flow channel (101), a fuel oil fuel flow channel (102) and an air flow channel (103) in sequence from the center of the burner body (1) to the periphery; the nozzle (2) is provided with a methanol injection flow channel (201), a fuel oil injection flow channel (202) and an air injection flow channel (203) in sequence from the center of the nozzle (2) to the periphery, the methanol injection flow channel (201) is connected to the methanol fuel flow channel (101), the fuel oil injection flow channel (202) is connected to the fuel oil fuel flow channel (102), and the air injection flow channel (203) is connected to the air flow channel (103); the flame stabilizing disc (3) is provided at the end of the nozzle (2), and the flame stabilizing disc (3) is provided at the end of the nozzle (2). A central through hole (301), a plurality of deflection holes (302) and a plurality of peripheral holes (303) are provided on the surface, wherein the central through hole (301) is provided at the central portion of the flame-stabilizing disc (3), the peripheral holes (303) are provided at the peripheral portion of the flame-stabilizing disc (3), and the plurality of peripheral holes (303) are evenly distributed along the circumference of the flame-stabilizing disc (3) with the axis of the flame-stabilizing disc (3) as the center, the deflection hole (302) is provided between the central through hole (301) and the peripheral holes (303), and the plurality of deflection holes (302) are evenly distributed along the circumference of the flame-stabilizing disc (3) with the axis of the flame-stabilizing disc (3) as the center, and a deflection plate (304) is provided on the side wall of each deflection hole (302), and the deflection plate (304) is used to change the flow direction of fuel sprayed from the fuel injection channel (202).

2. The mixed fuel burner for an industrial kiln according to claim 1, characterized in that: The flame stabilizing disc (3) is an inverted frustum structure that is passed through from top to bottom, and the outer wall contour line and the inner wall contour line are parallel to each other. The top diameter of the flame stabilizing disc (3) is larger than the bottom diameter.

3. The mixed fuel burner for an industrial kiln according to claim 1, characterized in that: The central through hole (301) is directly connected to the methanol injection flow channel (201), the deflection hole (302) is directly connected to the fuel injection flow channel (202), and the peripheral hole (303) is directly connected to the air injection flow channel (203).

4. The mixed fuel burner for an industrial kiln according to claim 1, characterized in that: The central through hole (301) is provided on the bottom surface of the flame stabilizing disc (3), the deflection hole (302) and the peripheral hole (303) are both provided on the side conical surface of the flame stabilizing disc (3), the central through hole (301) and the peripheral hole (303) are both circular holes, and the deflection hole (302) is a triangular hole.

5. The industrial furnace mixed fuel burner according to claim 4, characterized in that: The portion of the deflection hole (302) adjacent to the peripheral hole (303) is the pointed end of the triangular hole, and the portion of the deflection hole (302) adjacent to the central through hole (301) is the blunt end of the triangular hole.

6. The industrial furnace mixed fuel burner according to claim 5, characterized in that: The shortest distance between the highest point of the pointed end of the deflection hole (302) on the side conical surface of the flame stabilizing disc (3) and the top of the side conical surface of the flame stabilizing disc (3) is smaller than the shortest distance between the highest point of the peripheral hole (303) on the side conical surface of the flame stabilizing disc (3) and the top of the side conical surface of the flame stabilizing disc (3).

7. The industrial furnace mixed fuel burner according to claim 1, characterized in that: The number of the deflection holes (302) and the peripheral holes (303) is the same, and each deflection hole (302) is located between two adjacent peripheral holes (303).

8. The mixed fuel burner for an industrial kiln according to claim 1, characterized in that: The baffles (304) have the same shape as the baffle holes (302), and each baffle (304) covers a portion of a baffle hole (302).

9. The mixed fuel burner for an industrial kiln according to claim 1, characterized in that: An extension line of the deflector (304) in the extending direction forms an angle with a tangent line of the inner wall of the flame stabilizing disc (3) at a position where the deflector (304) and the flame stabilizing disc (3) meet.

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