Step-by-step mixed type forced guiding turbulent burner suitable for high-viscosity fuel

Abstract

The invention discloses a step-by-step mixed type forced guiding turbulent burner suitable for high-viscosity fuel, which comprises a burner shell and a full-covering type airflow forced guiding structure, the full-covering type airflow forced guiding structure is arranged at an outlet end and comprises a plurality of swirl vanes, and the connecting ends of every two adjacent swirl vanes are arranged in a laminated and staggered manner to keep an airflow gap layer. The plurality of rotational flow blades are arranged on the section of the outlet end in a full-covering manner; the tail end mixing structure comprises a radial fuel pipe arranged in the swirl vane, and a plurality of fuel spray holes are formed in the radial fuel pipe towards the outlet end. Fuel and air in a channel between the blades are fully mixed through the injection straight holes in the front edges of the blades, uniform and fully-mixed mixed gas is formed at an outlet of the combustor, and stable premixed flame with the moderate highest flame temperature can be formed in a hearth by increasing the angle of the rotational flow blades, enhancing the backflow effect and improving the flame stability; the combustion efficiency is improved, and NOx emission is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of incinerator burners, and in particular to a step-by-step mixing type forced-guide swirl burner suitable for high-viscosity fuel. Background Art

[0002] In the field of industrial incineration treatment, the burner is the core equipment, and its combustion efficiency, pollutant emission performance and fuel adaptability directly affect the operating economy and environmental protection compliance of the incineration system.

[0003] Prior art application number: 202210530621.5, discloses an air-fuel dual-stage high-proportion hydrogen-doped ultra-low nitrogen burner, method, and boiler. It is equipped with a primary mixed fuel distribution chamber, which mixes the fuel with combustion-supporting air in a premixing chamber through fuel diffusion holes. In essence, the fuel and combustion-supporting air are mixed within the burner. If the premixed gas reaches a combustible concentration within the shell, it may cause pre-ignition due to high shell temperature or sparks, requiring higher safety requirements. Otherwise, there is a risk of flashback and explosion. When the premixed gas flow rate or concentration fluctuates, the flame stability is easily affected, and flameout may occur. The premixed gas ratio must be precisely controlled to maintain the flame shape.

[0004] In addition, the swirl structure design of some burners is unreasonable, and the combustion-supporting air is prone to "short-circuiting" phenomenon. For example, the direct airflow in some areas does not participate in the swirl. For example, the low-nitrogen gas burner disclosed in Application No. 202111209131.7 and the multi-stage swirl burner disclosed in Application No. 201910253680.0 are both equipped with a swirl blade structure, but there is a partial area between the two adjacent blades that allows the airflow diameter to be blown out, resulting in insufficient swirl intensity and weak reflow effect. The underutilized airflow not only reduces the mixing efficiency, but also takes away the heat from the furnace, increases energy consumption, and is difficult to adapt to fluctuations in fuel load due to poor flame stability.

[0005] In view of the above reasons, it is necessary to propose a step-by-step mixing forced-guide swirl burner suitable for high-viscosity fuel to solve the above problems. Summary of the Invention

[0006] The purpose of the present invention is to overcome the defects in the prior art and provide a step-by-step mixing forced-guide swirl burner suitable for high-viscosity fuel.

[0007] To achieve the above object, the technical solution of the present invention is as follows: A step-by-step mixing forced-guide swirl burner suitable for high-viscosity fuel, comprising: The burner shell has a cylindrical shell with a cylindrical cavity formed inside. The combustion air enters the cylindrical cavity from its inlet end and flows out from its outlet end. A fully covered forced airflow guide structure is provided at the outlet end and includes a plurality of swirl blades. The connecting ends of two adjacent swirl blades are arranged in a stacked and staggered manner to maintain an airflow gap layer. The stacked and staggered arrangement is such that the adjacent ends of the two adjacent swirl blades form an overlapping area with an overlapping width in the axial direction, and the plurality of swirl blades are arranged to form a fully covered cross-section of the outlet end. The end mixing structure includes at least a radial fuel pipe arranged inside the swirl blade, and the radial fuel pipe is arranged in the overlapping area. A radial fuel pipe is provided in each overlapping area, and the radial fuel pipe is provided with a plurality of fuel nozzles toward the outlet end, so that the fuel sprayed from the fuel nozzles is mixed with the combustion-supporting air guided out by the air flow gap layer.

[0008] Furthermore, it also includes a fuel supply structure, which includes a central fuel pipe, the central fuel pipe is located on the internal axis of the burner shell, the front end of the central fuel pipe is connected to each swirl blade, the front end of the central fuel pipe is connected to each radial fuel pipe, and the side of the central fuel pipe is connected to a side feed pipe for fuel supply, and the side feed pipe passes through the side wall of the burner shell.

[0009] Furthermore, the central fuel pipe is divided into a front end pipe and a rear end pipe, the inner diameter of the rear end pipe is smaller than the inner diameter of the front end pipe, and the inner diameter of the side feed pipe is the same as the inner diameter of the rear end pipe.

[0010] Furthermore, the burner housing is provided with a necked tube portion, which forms an annular inner concave cavity inside the burner housing. The annular inner concave cavity is provided with a plurality of tangential nozzles around the axis on the side wall facing the outlet end. The tangential nozzles are arranged along the tangential direction of the annular inner cavity, and guide the airflow along the tangential direction. The tangential nozzles form a first separation angle A between the airflow entry direction and the axial direction; the annular inner concave cavity is connected to the outside of the burner housing with a drainage pipe.

[0011] Furthermore, an adjustment cone is provided in the burner housing along the axial direction, and the adjustment cone is arranged at the position of the necked tube portion and cooperates therewith; The adjusting cone is configured to be positionally adjustable along the axial direction, and the air flow characteristics at the throat of the constricted tube portion are adjusted by changing the position of the adjusting cone.

[0012] Furthermore, the fluid is guided and ejected from the outlet end of the burner housing through the airflow gap layer between the swirl blades, and the ejection direction of the fluid from the airflow gap layer forms a second separation angle B with the axial direction.

[0013] Furthermore, the first separation angle is smaller than the second separation angle, and (1 / 2)B<A<B.

[0014] Furthermore, 65°<the second separation angle B<85°.

[0015] The advantages and beneficial effects of the present invention include: It utilizes straight injection holes on the leading edges of the blades to thoroughly mix the fuel with the air in the passages between the blades, forming a uniform and well-mixed mixture at the burner outlet. By increasing the angle of the swirl blades, the recirculation effect is enhanced, improving flame stability. This allows for a stable premixed flame with a moderate maximum flame temperature to be formed within the furnace, thereby improving combustion efficiency and reducing NOx emissions. The novel burner structure proposed by the present invention has the advantages of being simple in structure, easy to manufacture, simple to implement, and low in cost.

[0016] This invention utilizes a Venturi constriction structure and a tangential nozzle design, combined with dynamic control of an adjustable cone, to achieve precise adjustment of the gas mixing ratio. The matching angles of 50° and 80° enhance swirl superposition, improving mixing efficiency and maintaining stable combustion over a wide load range, overcoming the limitations of traditional burners with fixed mixing ratios.

[0017] The adjustable cone position can be flexibly adjusted to ensure oxygen supply during high loads, balance energy consumption and emissions during normal loads, and suppress pollutants through high-proportion diversion during low loads. This achieves highly efficient incineration without complex equipment, achieving a combustion efficiency of 99.5% and NOx emissions as low as 120mg / m³, significantly improving the equipment's applicability and environmental performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is an axonometric diagram of a step-by-step mixing forced-guide swirl burner suitable for high-viscosity fuels according to the present invention; Figure 2 It is a front view of the outlet end of the present invention; Figure 3 It is a schematic longitudinal section of the present invention; Figure 4 It is an exploded view of the present invention; Figure 5 Schematic diagram of the necked tube portion and two separation angles of the present invention; Figure 6 It is a schematic diagram of the position of the adjustment cone of the present invention; Figure 7 It is a three-dimensional diagram of the screw rod adjustment mechanism of the present invention; Figure 8 It is an exploded view of the screw rod adjustment mechanism of the present invention; In the figure: 1. Burner shell; 2. Inlet end; 3. Outlet end; 4. Swirl blades; 5. Airflow gap layer; 6. Overlap width; 7. Radial fuel pipe; 8. Fuel nozzle; 9. Central fuel pipe; 10. Side feed pipe; 11. Front end pipe; 12. Rear end pipe; 14. Neck pipe; 15. Annular inner cavity; 16. Tangential nozzle; 17. Drain pipe; 18. Adjustment cone; A. First separation angle; B. Second separation angle; 21. Plug; 22. Guide support sleeve; 23. Drive screw; 24. Bevel gear set; 25. Drive shaft; 26. Servo motor; 27. Guide rail; 28. Partial thread; 29. ​​Screw adjustment mechanism. DETAILED DESCRIPTION

[0019] The specific embodiments of the present invention are further described below in conjunction with the examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0020] Example 1: On the basis of the existing common oil burner, the fuel injection method is changed. The fuel flows out from the internal channel of the swirl blade 4, and then is injected at the edge of the swirl blade 4 to mix with the swirling air. The mixed gas is burned in the furnace. Specifically, it includes swirl blades 4, fuel pipes, support plates, and a burner housing 1. It uses a method of spraying at the edge of the swirl blades 4 through the internal channels of the swirl blades 4 to mix with the swirl air, thereby improving combustion efficiency and reducing emissions.

[0021] The swirl blades 4 are mainly used to form backflow and fuel mixing for the burner. The setting of the swirl blades 4 enables the outlet end 3 to form a fully covered airflow forced guide structure. Specifically, the connection ends of two adjacent swirl blades 4 are in a stacked staggered setting to maintain an airflow gap layer 5. The stacked staggered setting is so that the ends of two adjacent swirl blades 4 close to each other form an overlapping area with an overlapping width 6 in the axial direction, and multiple swirl blades 4 form a fully covered arrangement on the cross section of the outlet end 3; in this embodiment, four swirl blades 4 are provided, and the swirl blades 4 are fan-shaped and arranged along a spiral path around the central fuel pipe 9, so that the edges of the two adjacent swirl blades 4 are in a stacked staggered shape and form an airflow gap layer 5, and the combustion-supporting air entering from the inlet end 2 is guided through the swirl blades 4 and ejected from the airflow gap layer 5, so that the ejected mixed gas moves around the axis. The multiple swirl blades 4 are connected head to tail in a staggered and overlapping manner, thereby avoiding the phenomenon of "short circuit" of the combustion-supporting air and allowing all the gases flowing through to participate in the swirl. When observed from the axial direction, it can be seen that the outlet end 3 of this structure is completely blocked by the swirl blades 4 to form a fully covered arrangement. At the same time, the setting angle of the swirl blades 4 is also increased (thereby increasing the second separation angle B); this design can enhance the swirl intensity and backflow effect, while improving the forced mixing ability of the fuel and the combustion-supporting air, thereby effectively maintaining flame stability and avoiding flameout.

[0022] When the burner is operating, the combustion-supporting air, guided by the swirl blades 4, forms a rotating airflow (swirl)—that is, the airflow moves along the burner's axis while also rotating in a circular motion around the axis. After exiting the burner outlet, this rotating airflow diffuses due to centrifugal force, forming a low-pressure zone in the center of the burner outlet. To fill this low-pressure zone, the high-temperature flue gas (combustion products) within the furnace reverses direction, flowing back from the furnace to the vicinity of the burner outlet (near the flame root), a process known as recirculation. The larger the second separation angle B, the greater the airflow rotation, the more pronounced the low-pressure zone at the center of the outlet, and the greater the ability to attract high-temperature flue gas backflow. Conversely, if the second separation angle B is smaller, or even if the burner is ejected in a straight-blowing manner, the airflow moves in a straight axial direction, with no low-pressure zone at the center of the outlet and virtually no recirculation. In this embodiment, the second separation angle B is set to 65° < second separation angle B < 85°.

[0023] The fuel pipe includes a radial fuel pipe 7, a central fuel pipe 9, and a side feed pipe 10. The root of the swirl blade 4 is connected to the central fuel pipe 9. The outside of the swirl blade 4 can be configured to be connected to the burner housing 1 (an outer ring fixing frame can also be fixedly connected to the outer periphery of all swirl blades 4, and connected and fixed to the burner housing 1 through the outer ring fixing frame, so as to facilitate disassembly and maintenance).

[0024] The central fuel pipe 9, located on the central axis of the burner, consists of two nested sections. The front pipe 11 is thicker, with an inner diameter identical to the outer diameter of the rear pipe 12. The rear pipe 12 is nested within the front pipe 11 to form a single, integrated central pipe. This design, based on the principles of "fluid dynamics adaptability" and "functional zoning," achieves a synergistic optimization of fuel delivery efficiency, structural adaptability, and manufacturing feasibility through its two-section structure and dimensional differences. The specific principles are as follows: The front pipe must directly connect to the radial fuel channels within the swirl vanes. Its core function is to "divide" the fuel to multiple swirl vanes, requiring a larger flow cross-section and a more complex diversion structure. The rear pipe, whose primary function is to "converge" fuel from the side feed pipes and deliver it to the front pipe, only needs to meet the requirement of linear fuel delivery, thus allowing for a thinner pipe diameter. According to the principle of fluid resistance balance, after the fuel enters the rear pipe from the side feed pipe 10, it is diverted through the front pipe to multiple swirl vane channels (a "divergence process" that increases resistance). The thinner rear end tube design compensates for pressure loss during diversion by increasing local flow velocity (according to Bernoulli's principle, smaller tube diameters increase flow velocity for the same flow rate). The thicker front end tube reduces fluid resistance before diversion, preventing uneven fuel supply due to excessive local pressure drops. Analysis of the assembly feasibility of the nested structure suggests that the front end tube has the same inner diameter as the rear end tube, allowing the two sections to nest together to form a single unit. This ensures a tight connection and simplifies the assembly process—no complex flanges or welds are required; axial positioning and fixation are achieved simply through nesting.

[0025] The head of the front pipe 11 is connected to the swirl vane 4 and communicates with the internal fuel passageway within the corresponding swirl vane 4. The head of the front pipe 11 has holes with the same cross-sectional shape, size, and channel orientation as the radial fuel pipe 7 within the corresponding swirl vane 4, and these holes are evenly distributed, thereby reducing flow resistance. The rear pipe 12 is connected to the side feed pipe 10 at a certain point and has the same diameter as the rear pipe 12. A plug 21 is provided at the end of the rear pipe 12 to facilitate the processing of the central fuel pipe 9. The side feed pipe 10 passes through the shell and communicates with the central fuel pipe 9. The outer end of the side feed pipe 10 is provided with a flange connection structure at a certain distance from the burner shell 1 for connecting to the flange of the external fuel supply system outlet. Fuel enters the side feed pipe 10 through the supply system and enters the radial fuel pipe 7 within the swirl vane 4 through the central fuel pipe 9.

[0026] A hollow structure is formed at least within the swirl outlet side of the swirl vanes 4, forming radial fuel pipes 7. These pipes 7 communicate with circumferential fuel holes formed in the central fuel pipe 9. A row of fuel nozzles 8 are evenly distributed along the radial fuel pipes 7 along the swirl vanes 4. These radial fuel pipes 7 are arranged within overlapping regions, with each overlapping region having a radial fuel pipe 7. The fuel nozzles 8 are arranged on the outer surfaces of the swirl vanes 4, directing fuel injection outward. The injected fuel then collides with the outer swirl vanes 4, dispersing the fuel and causing vertical cross-mixing of the fuel with the combustion air passing through the swirl vanes 4. This improves fuel mixing and forms a uniform mixed gas at the burner outlet. Specifically, the fuel is injected into the air gap layer 5 between the swirl vanes 4, where it mixes with the combustion air.

[0027] Example 2: This embodiment is additionally provided with a Venturi-type necking structure and a tangential nozzle 16 drainage design on the basis of the previous embodiment.

[0028] Specifically, a necked tube portion 14 is provided at a certain section of the burner housing 1 at the front end of the plug 21 to form a Venturi tube structure, thereby forming a Venturi effect. When the airflow passes through the necked portion, the flow velocity increases and the pressure decreases, and auxiliary gas, such as secondary combustion air, inert gas or reducing gas, can be inhaled through the external drainage pipe 17. An annular inner concave cavity 15 is formed in the surrounding necked tube portion 14, and a plurality of tangential nozzles 16 are provided on the side wall thereof facing the burner outlet end 3, so that the induced gas is sprayed into the burner shell 1 in a tangential direction at a first separation angle A, thereby causing the induced gas to form a circular motion in the burner shell 1, and forms a rotational mixing with the main combustion air, and drives the main combustion air to rotate synchronously, thereby forming a preliminary rotation in the burner shell 1, and then further rotationally guides the flow through the swirl blades 4, thereby enhancing the rotation effect of the fluid at the outlet end 3; it can be understood that the tangential nozzles 16 and the swirl blades 4 have the same rotational guidance direction for the fluid, and the difference lies in the difference in the guidance angles of the two. Specifically, the fluid (main combustion air and fuel mixture) ejected from the airflow gap layer 5 between the swirl blades 4 forms a second separation angle B with the axis, and is designed to be (1 / 2)B<A<B. This angular relationship ensures that the tangentially injected drainage gas can enhance the swirl intensity of the main airflow through rotational kinetic energy, while not causing airflow collision due to excessive angle, thereby achieving the synergistic effect of "supplementary mixing + enhanced swirl".

[0029] In actual use, the gas introduced by the drainage pipe 17 can be the same gas as the combustion-supporting air entering the inlet end 2, or it can be a different gas. The user can switch and select according to needs.

[0030] The tangential nozzle 16 injects the flow at angle A, creating a gradient difference with the angle B of the mixed flow at the outlet 3. This "swirl superposition" enhances the overall swirl intensity, shortening the fuel-gas mixing time by 20%-30%, improving mixing uniformity by over 15%, and reducing localized high temperatures and pollutant emissions. When processing high-viscosity fuels, high-temperature preheated air can be introduced through the flow tube 17 (to enhance atomization). To reduce NOx emissions, an inert gas (such as flue gas recirculation) can be introduced. The blending ratio is dynamically optimized by adjusting the cone 18, expanding the burner's adaptability to fuel viscosities ranging from 100 to 1500 cSt.

[0031] Example 3: This embodiment adds an adjustment cone 18 on the basis of the second embodiment, so as to match the design of the necked tube portion 14 and construct a composite airflow control system of "graded drainage-dynamic adjustment-directional mixing".

[0032] Specifically, an adjustment cone 18 is provided in the burner housing 1 along the axial direction, and the adjustment cone 18 is arranged at the position of the neck tube portion 14 and cooperates therewith; the adjustment cone 18 is configured to be adjustable in position along the axial direction, and the position of the adjustment cone 18 is changed to adjust the air flow characteristics at the throat position of the neck tube portion 14.

[0033] The adjustment cone 18 is positioned inside the constricted tube section 14 along the burner axis. Its axial position is adjustable via a drive mechanism, allowing it to be moved to the front, middle, and rear of the constricted tube section 14. Its core function is to change the flow cross-section at the constriction: as the cone approaches the front end of the constriction, the throat cross-section increases; as the cone approaches the rear end of the constriction, the throat cross-section decreases, thereby dynamically controlling the mixture ratio and flow rate of the main combustion air and the drainage gas.

[0034] The Venturi effect draws in the drainage gas, and combined with the adjustment of the throat cross-section by the regulating cone 18, the ratio of the main combustion air to the drainage gas can be flexibly controlled, resolving the problem of traditional burners with fixed gas ratios and difficulty adapting to fluctuating fuel composition. The Venturi-type constriction structure utilizes the airflow's own kinetic energy to draw in the drainage gas, eliminating the need for additional pressurization equipment and reducing energy consumption. The regulating cone 18 uses mechanical adjustment, resulting in a fast response (adjustment time <5s) and compatibility with the existing shell structure, eliminating the need for major modifications.

[0035] Specific embodiment: The following embodiment takes the incinerator burner for treating industrial mixed waste liquid as an example. The drainage pipe 17 can introduce different gases according to the working conditions, such as room temperature combustion air, flue gas recycling gas or reducing gas. The specific parameters and effects are as follows: Example 1: High-load incineration, with a processing capacity of 100%, requires enhanced combustion intensity.

[0036] Adjust the position of the cone 18: the necked tube portion 14 is closer to the front (1 / 3 of the length from the necking front end).

[0037] Throat cross-section state: the cross-section is the largest (diameter 100mm), and the main combustion air flow resistance is the smallest.

[0038] Airflow parameters: Main combustion air velocity: 18m / s, conventional wind speed, to meet high-load oxygen supply requirements; drainage gas intake: 15% of the main airflow, introducing normal temperature combustion air with an oxygen content of 21%; the tangential nozzle 16 angle A=50°, forming a gradient with the swirl blade 4 outlet airflow angle B=80°, and the drainage gas supplements the swirl kinetic energy along the tangential direction.

[0039] The main combustion effect is due to the sufficient combustion-supporting air, combined with the "secondary swirl enhancement" of the 50° tangential airflow, which allows the fuel and air to be evenly mixed. The flame length reaches 2.5m and the combustion efficiency is 99.5%. There is no local high-temperature area, and the CO emission concentration is less than 50mg / m³, meeting the needs of rapid incineration under high load.

[0040] Example 2: Conventional load incineration, with a processing capacity of 70%, requires stable combustion.

[0041] The position of the adjusting cone 18 is in the middle of the necked tube portion 14, i.e., in the middle of the necking section.

[0042] Throat cross-section: medium cross-section, 80mm diameter, balanced flow of main combustion air and drainage gas.

[0043] Airflow Parameters: Main combustion air velocity: 22m / s, a moderate flow rate that balances mixing efficiency and energy consumption. Drainage air intake: 30% of the main airflow; 50% ambient temperature combustion air + 50% flue gas recirculation, with an oxygen content of 19%. Tangential nozzles, with an angle difference of 50° (A=50°) and 80° (B=80°), create a "progressive swirl" to avoid airflow counterflow.

[0044] Combustion Performance: Excellent flame stability, with fluctuations less than ±2%, suitable for continuous operation, with an average daily run time of over 20 hours without flameout. Flue gas recirculation suppresses localized high temperatures, resulting in NOx emissions of 250mg / m³, a 15% reduction compared to operating with pure combustion air.

[0045] Example 3: Low load + low pollution incineration, processing capacity 30%, pollutant emissions need to be controlled.

[0046] The position of the adjusting cone 18 is at the rear of the necked tube portion 14 and 1 / 3 of the length from the rear end of the necking tube portion.

[0047] Throat cross-section state: the cross-section is the smallest, with a diameter of 60mm; the main combustion air velocity is the highest and the Venturi effect is the strongest.

[0048] Airflow parameters: Main combustion air velocity: 28m / s, high-speed airflow enhances drainage capacity; drainage gas intake: 50% of the main airflow, introducing 80% flue gas recycling gas + 20% reducing gas, oxygen content 16%; the rotating airflow at the tangential nozzle 16 angle A=50° and the airflow of the swirl blade 4 at B=80° form a "superimposed swirl" to extend the fuel residence time.

[0049] Combustion Performance: The low-oxygen, reducing atmosphere significantly suppresses NOx generation, reducing emission concentrations to 120 mg / m³, a 52% reduction compared to conventional operating conditions. A high draft ratio prevents the flame from being too short at low loads, maintaining a stable flame length of 1.2 m and unburned matter emissions below 30 mg / m³.

[0050] By dynamically adjusting the position of the adjusting cone 18, the burner can adapt to industrial waste liquids of different properties within a wide load range. This embodiment combines the angle matching design of the first separation angle A of 50° and the second separation angle B of 80°, which not only utilizes the superposition of swirls to enhance the mixing efficiency, but also avoids the energy loss caused by airflow collision, thereby achieving the synergistic effect of "efficient combustion + flexible regulation + low emissions".

[0051] In this embodiment, axial position adjustment can be achieved through a driving mechanism. Specifically, in this embodiment, the driving mechanism is a screw adjustment mechanism 29, which includes a screw adjustment mechanism 29 arranged at the end of the plug 21 and along the axis, and includes a guide support sleeve 22, a drive screw 23, a bevel gear set 24, a drive shaft 25, and a servo motor 26; the guide support sleeve 22 is fixedly connected to the central fuel pipe 9, and the drive screw 23 is rotatably arranged inside the guide support sleeve 22. The guide support sleeve 22 is provided with a long guide rail 27. Preferably, the end of the guide support sleeve 22 is a bullet-shaped tip, and the guide rail 27 passes through the side wall of the guide support sleeve 22. The adjusting cone 18 is sleeved on the outside of the guide support sleeve 22 and is slidably connected. The adjusting cone 18 is provided with a partial thread 28 that passes through the guide rail 27 and is threadedly connected to the drive screw 23. The drive screw 23 is connected to the drive shaft 25 in the plug 21 through the bevel gear set 24, and the other end of the bevel gear set 24 passes through the burner housing 1 and is connected to the output end of the servo motor 26.

[0052] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A step-by-step mixing forced-guide swirl burner suitable for high-viscosity fuel, characterized in that: include: The burner shell has a cylindrical shell with a cylindrical cavity formed inside. The combustion air enters the cylindrical cavity from its inlet end and flows out from its outlet end. A fully covered forced airflow guide structure is provided at the outlet end and includes a plurality of swirl blades. The connecting ends of two adjacent swirl blades are arranged in a stacked and staggered manner to maintain an airflow gap layer. The stacked and staggered arrangement is such that the adjacent ends of the two adjacent swirl blades form an overlapping area with an overlapping width in the axial direction, and the plurality of swirl blades are arranged to form a fully covered cross-section of the outlet end. The end mixing structure includes at least a radial fuel pipe arranged inside the swirl blade, and the radial fuel pipe is arranged in the overlapping area. The radial fuel pipe is provided with a plurality of fuel nozzles toward the outlet end, so that the fuel sprayed from the fuel nozzles is mixed with the combustion-supporting air guided out of the air flow gap layer.

2. The step-by-step mixing forced-guide swirl burner suitable for high-viscosity fuel according to claim 1, characterized in that: It also includes a fuel supply structure, which includes a central fuel pipe. The central fuel pipe is located on the internal axis of the burner shell. The front end of the central fuel pipe is connected to each swirl blade. The front end of the central fuel pipe is connected to each radial fuel pipe. The side of the central fuel pipe is connected to a side feed pipe for fuel supply, and the side feed pipe passes through the side wall of the burner shell.

3. The step-by-step mixing forced-guide swirl burner suitable for high-viscosity fuel according to claim 2, characterized in that: The central fuel pipe is divided into a front end pipe and a rear end pipe. The inner diameter of the rear end pipe is smaller than that of the front end pipe. The inner diameter of the side feed pipe is the same as that of the rear end pipe.

4. The step-by-step mixing forced-guide swirl burner suitable for high-viscosity fuel according to claim 1, characterized in that: The burner housing is provided with a necked tube portion, which forms an annular inner concave cavity inside the burner housing. The annular inner concave cavity is provided with a plurality of tangential nozzles around the axis on the side wall facing the outlet end. The tangential nozzles are arranged along the tangential direction of the annular inner cavity, and guide the airflow along the tangential direction. The tangential nozzles form a first separation angle A between the airflow entry direction and the axial direction; the annular inner concave cavity is connected to the outside of the burner housing with a drainage pipe.

5. The step-by-step mixing forced-guide swirl burner suitable for high-viscosity fuel according to claim 4, characterized in that: An adjusting cone is provided in the burner housing along the axial direction, and the adjusting cone is arranged at the position of the necked tube portion and cooperates with the necked tube portion; The adjusting cone is configured to be positionally adjustable along the axial direction, and the air flow characteristics at the throat of the constricted tube portion are adjusted by changing the position of the adjusting cone.

6. A step-by-step mixing forced-guide swirl burner suitable for high-viscosity fuel according to claim 1 or 4, characterized in that: The fluid is ejected from the outlet end of the burner housing through the air flow gap layer between the swirl blades, and the ejection direction of the fluid from the air flow gap layer forms a second separation angle B with the axial direction.

7. The step-by-step mixing forced-guide swirl burner suitable for high-viscosity fuel according to claim 6, characterized in that: The first separation angle is smaller than the second separation angle, and (1 / 2)B<A<B.

8. The step-by-step mixing forced-guide swirl burner suitable for high-viscosity fuel according to claim 6, characterized in that: 65°<second separation angle B<85°.

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