CN109855096B

CN109855096B - Multistage cyclone burner

Info

Publication number: CN109855096B
Application number: CN201910253680.0A
Authority: CN
Inventors: 苏波; 林继铭; 杨建红; 张勇; 乐光明
Original assignee: Huaqiao University
Current assignee: Huaqiao University
Priority date: 2019-03-30
Filing date: 2019-03-30
Publication date: 2024-06-07
Anticipated expiration: 2039-03-30
Also published as: CN109855096A

Abstract

The invention discloses a multistage cyclone burner, which comprises an outer air cylinder, an inner air cylinder, a blunt disk, an inner ring cyclone blade, an outer ring cyclone blade, a primary fuel pipe and a blunt disk through hole, wherein the front end opening of the outer air cylinder is connected with a conical hood; the second-stage fuel pipe is matched with the inner ring swirl vane, and the third-stage fuel pipe is matched with the outer ring swirl vane. The fuel and the air are mixed in layers, which is beneficial to enhancing the mixing effect of the fuel gas and the air. And the heat radiation transfer between the component and the surrounding high-temperature environment is slowed down, so that the service life of the component is prolonged.

Description

Multistage cyclone burner

Technical Field

The invention relates to a combustor, in particular to a multi-stage cyclone combustor, wherein air and fuel are mixed and combusted in multiple stages.

Background

The industrial revolution is continuously advancing, and the shortage of energy supply and environmental pollution become the main problems in the field of human society industry, representing insufficient combustion, and at the same time, there is also a great waste of energy. The geometry of the burner as a fuel combustion generating device influences various combustion characteristics, so that an excellent burner structure is provided, and the combustion characteristics of the burner are improved better and improved, which is an important research problem for those skilled in the industry. Different combustor structures have different influence effects on the mass, momentum and heat transfer of the combustion process, so that the whole combustion process is further influenced, and therefore, the design of the high-efficiency combustor structure has very important practical significance and application value for industrial furnaces and even the combustion field.

The prior burner has the technical problems that: the fuel is rapidly ignited by surrounding high-temperature flue gas air after being sprayed out, released heat is concentrated at the upstream of the burner, so that the temperature near a flame stabilizing disc, a nozzle and a head cover which are formed by inner ring swirl blades and a blunt disc is too high, and under the condition that high temperature and excessive air exist simultaneously, a workpiece is oxidized and decarburized, the hardness of the workpiece is reduced, and the service life is greatly reduced; the fuel and air are not uniformly mixed, the combustion is insufficient, the combustion efficiency is low, and a large amount of polluted gas is generated.

Disclosure of Invention

The invention provides a multistage cyclone burner which overcomes the defects existing in the background technology. The technical scheme adopted for solving the technical problems is as follows:

The utility model provides a multistage cyclone burner, includes along the outer dryer and the interior dryer of coaxial setting, this outer dryer front end opening connection toper hood, still includes: the blunt disk is arranged in the center of the front opening of the inner air duct and is perpendicular to the central axis of the inner air duct, the center of the blunt disk is provided with a through hole, and a plurality of ventilation holes are uniformly distributed around the through hole; a plurality of inner ring swirl blades which are arranged in an annular array with the blunt disk as a center, wherein the inner end surface is connected with the outer peripheral surface of the blunt disk, and the outer end surface is connected with the inner peripheral surface of the inner air duct; the mounting ring is arranged at the front end opening of the outer air duct and is coaxial with the inner air duct and the outer air duct; the inner wind barrel is taken as a center, a plurality of outer ring swirl blades are distributed in an annular array, the inner end face is connected with the outer circumferential face of the inner wind barrel, the outer end face is connected with the inner circumferential face of the mounting ring, an annular wind channel is formed between the outer circumferential face of the mounting ring and the inner circumferential face of the outer wind barrel, and the deflection directions of the inner ring swirl blades and the outer ring swirl blades are the same; the primary fuel pipe is axially arranged and is in butt joint with the through hole; a plurality of secondary fuel pipes which are axially arranged in the inner air duct and are circularly arrayed by taking the blunt disk as a center, wherein the front end of each secondary fuel pipe extends out of the inner air duct and is provided with a nozzle, and the nozzle is positioned in the head cover; the front ends of the three-level fuel pipes extend out of the head cover and incline and shrink towards the central axis of the burner.

Compared with the background technology, the technical proposal has the following advantages:

1. The air in the inner air cylinder and the outer air cylinder is divided into four parts by the vent hole, the inner ring swirl blades, the outer ring swirl blades and the annular air channel on the blunt disk, the primary fuel pipe is connected with the central through hole of the blunt disk, the secondary fuel pipes are uniformly distributed in the inner ring swirl blades, and the tertiary fuel pipes are uniformly distributed in the outer ring swirl blades, so that the mixing of fuel gas and air is enhanced.

2. When the incoming cold air enters the inner air duct, part of the air generates rotary motion through the inner ring swirl blades, is mixed with the secondary fuel, and part of the air forms straight jet flow through the vent holes, carries the primary fuel to move towards the outlet direction of the burner, and simultaneously mixes, and ignites the mixed gas under the action of high-temperature flue gas. Because of the effect of the direct jet flow, the ignition position of the primary fuel moves downstream, combustion occurs at the downstream of the flame stabilizing disc, the high-temperature area is at a certain distance from the flame stabilizing disc, and in the certain distance, the radiation of heat to the components is reduced, so that the service life of the flame stabilizing disc is prolonged. Also, after the secondary air and the secondary fuel are rotationally mixed, the ignited position of the secondary mixed gas moves towards the downstream of the burner, combustion does not occur near the nozzle of the secondary fuel pipe, and the service life of the nozzle is prolonged.

3. After the cold air flows through the annular air duct, a large amount of heat on the wall surface of the head cover can be taken away, the temperature of the head cover is reduced, and the service life of the head cover is prolonged.

4. The air of the vent hole of the blunt disk pushes the central backflow area to the downstream of the burner, so that the backflow area is longer and wider, the residence time of the high-temperature smoke products is increased, and the backflow area is used as a continuous ignition source of peripheral mixed gas, so that the combustion is more stable, and flameout and other phenomena are not easy to occur. The widening of the backflow area is beneficial to improving the flame combustion surface, so that the mixed gas is combusted more fully and has uniform temperature distribution, and local high temperature is avoided, so that the combustion condition is effectively improved, the emission of pollutants such as CO and NOx is reduced, the convection and radiation heat exchange with the surrounding environment is improved, and the heat exchange efficiency is enhanced.

5. In the tertiary air area, the direction of the nozzle of the tertiary fuel pipe points to the central axis to form a certain contraction angle, and meanwhile, the hood is contracted in an inclined way, so that flame generated by combustion is gathered to the central axis, and the rigidity of the flame is improved.

6. The nozzle of tertiary gas pipe surpasses the hood front end, carries the rear portion to burn gas, is favorable to abundant and the completion of burning, and temperature distribution is even simultaneously.

Drawings

The invention is further described below with reference to the drawings and examples.

FIG. 1 is a schematic perspective view of a multi-stage swirl burner of the present invention.

FIG. 2 is a right side schematic view of the multi-stage swirl burner of FIG. 1.

FIG. 3 illustrates a schematic cross-sectional view of the multi-stage swirl burner of FIG. 1.

Detailed Description

Referring to fig. 1 to 3, a multi-stage swirl burner includes an outer air duct 10 and an inner air duct 20 coaxially arranged, wherein the front end opening of the outer air duct 10 is connected with a conical hood 30, and the structures of the inner air duct 20, the outer air duct 10 and the hood 30 are now as structures, and refer to the invention patent application of application number 201110144131.3. The multi-stage swirl burner further includes a blunt disk 40, inner swirl vanes 50, mounting ring 60, outer swirl vanes 70, primary fuel pipe 81, secondary fuel pipe 82, and tertiary fuel pipe 83.

The blunt disk 40 is arranged in the center of the front opening of the inner air duct 20 and is perpendicular to the central axis of the inner air duct, the center is provided with a through hole 42, and six ventilation holes 44 are uniformly distributed around the through hole.

The inner ring swirl blades 40 are arranged in an annular array with the blunt disk 40 as a center, the inner end surface is connected with the outer peripheral surface of the blunt disk 40, and the outer end surface is connected with the inner peripheral surface of the inner air duct 20.

The mounting ring 60 is disposed at the front end opening of the outer air duct 10 and is coaxial with the outer air duct 10, and is used for fixing the outer ring swirl vanes 70, i.e. the mounting ring 60 is sleeved between the inner air duct and the outer air duct, and the mounting ring is supported and fixed inside the outer air duct 10 through a connecting rod.

The outer ring swirl vanes 70 are arranged in an annular array with the inner air duct 20 as a center, the inner end face is connected with the outer peripheral face of the inner air duct 20, and the outer end face is connected with the inner peripheral face of the mounting ring 60. An annular air duct 90 is formed between the outer circumferential surface of the mounting ring 60 and the inner circumferential surface of the outer air duct 10. The inner ring swirl vanes 50 and the outer ring swirl vanes 70 have the same yaw direction, and the air passes through the vanes and then rotates counterclockwise.

1. The two-stage and three-stage fuel pipes 81, 82, 83 are axially arranged and are provided with nozzles at the ends. The primary fuel pipe 81 is on the central axis of the burner and the front nozzle interfaces with the through hole 42. The secondary fuel pipes 82 are arranged in the inner air duct 20 in a circular array with the blunt disk 40 as a center, and the front ends of the secondary fuel pipes extend out of the inner air duct 20.

Six tertiary fuel pipes 83 are arranged in the mounting ring 60 in a circular array with the inner wind tube 20 as a center, and the front ends of the tertiary fuel pipes extend out of the head cover 30 and are inclined and contracted towards the central axis of the burner.

During combustion, primary air flows through the vent holes 44 of the blunt disk 40 to form a straight jet flow, the straight jet flow is mixed with primary fuel to form mixed gas, the combustion position moves downstream under the pushing of the straight jet flow, secondary fuel is evenly mixed with secondary rotating air flowing through the inner ring swirl vanes 50 after being sprayed out, and the secondary mixed gas is ignited and starts to fully burn under the combustion supporting effect of high-temperature products of the primary fuel combustion, and the same combustion position moves downstream. After being sprayed out, the three-stage fuel is uniformly mixed with the three-time rotating air flowing through the outer ring swirl vanes 70, and is combusted outside the hood, so that the combustion is complete and the flame length is adjusted.

The inner ring swirl vanes 50 and the outer ring swirl vanes 70 are each of a flat plate structure. Preferably, the outer ring swirl vanes 70 are angled with respect to the axis more than the inner ring swirl vanes 50 are angled with respect to the axis. Therefore, the swirl intensity of tertiary air is larger than that of secondary air, so that the heat and mass transfer of a mixed layer of peripheral and secondary mixed gas is stronger, the combustion is more sufficient, the heat and mass exchange of a flame frontal surface is facilitated, and the service life of important parts and the pollutant emission level are improved. Preferably, the outer ring swirl vanes 70 are angled 35-50 degrees from the axis and the inner ring swirl vanes 50 are angled 30-40 degrees from the axis.

The diameter of the through hole 42 in the center of the blunt disk is gradually increased along the axial direction, and the through hole is gradually expanded, after the fuel gas flows through the gradually expanded section, the flow velocity of the fuel gas is reduced, the surface area is enlarged, after leaving the nozzle, the contact area with air is large when mixing, the stay time is long because of the low flow velocity, the mixing effect with air is greatly enhanced, and the flameout phenomenon is not easy to generate. Preferably, the primary fuel pipe 81 nozzle divergence is 35-65 degrees.

The secondary fuel pipe 82 is provided with a plurality of nozzle openings uniformly arranged in the circumferential direction at the front end thereof, and the secondary fuel pipe sprays the material radially outwards, preferably with a radius of 2-5mm.

The tertiary fuel pipe 93 has an included angle 145-155 degrees from the central axis. The flame condensing effect of the flame form can be ensured, the flame length is adjusted, the flame rigidity is ensured, the flame beacon surface area is also improved, and the heat exchange efficiency is improved.

A suspension bracket 12 is provided on the inner wall of the outer tub 10 corresponding to the tertiary fuel pipe 83, and the tertiary fuel pipe 83 is axially movably mounted on the suspension bracket 12. Through adjusting the moving distance of the tertiary fuel pipe 83, the length of flame can be adaptively adjusted under the condition of not changing wind pressure, the working condition adaptability of the burner is improved, the working efficiency of the burner is improved, the operation is convenient, and the maintenance is simple. Preferably, the distance between the front nozzle of the tertiary fuel pipe 83 and the front end face of the head cover 30 is less than or equal to 300mm.

In this embodiment,: the blunt disk 40, inner ring swirl vanes 50, outer ring swirl vanes 70, and mounting ring 60 are on a single plane. The front ends of the gas branch pipes are provided with flow valves, the flow of the gas at each stage is precisely controlled by the flow valves, and the equivalence ratio of the mixed gas is precisely controlled, so that the energy saving and the full combustion are facilitated, and the flame length is adjusted. The primary fuel pipe has an inner diameter of 10-20mm and a wall thickness of 1-2mm; the inner diameter of the secondary fuel pipe is 8-12mm, and the wall thickness is 1-2mm; the inner diameter of the three-stage fuel pipe is 5-12mm, and the wall thickness is 1-2mm; the diameter of the inner wind tube is 380-430mm. The distance between the outer peripheral surface of the mounting ring 60 and the inner peripheral surface of the outer air duct 10 is 40-60mm, so that the annular air duct 90 has proper width, and the effect of reducing the temperature of the wall surface of the hood is improved. Preferably, the hood 30 is shrunk by an angle of 155-165 degrees.

The foregoing description is only illustrative of the preferred embodiments of the present invention, and therefore should not be taken as limiting the scope of the invention, for all changes and modifications that come within the meaning and range of equivalency of the claims and specification are therefore intended to be embraced therein.

Claims

1. The utility model provides a multistage cyclone burner, includes along the outer dryer and the interior dryer of coaxial setting, this outer dryer front end opening connection toper hood, its characterized in that: the air conditioner also comprises a blunt disk which is arranged in the center of the front opening of the inner air duct and is perpendicular to the central axis of the inner air duct, a through hole is arranged in the center, and a plurality of ventilation holes are uniformly distributed around the through hole; a plurality of inner ring swirl blades which are arranged in an annular array with the blunt disk as a center, wherein the inner end surface is connected with the outer peripheral surface of the blunt disk, and the outer end surface is connected with the inner peripheral surface of the inner air duct; the mounting ring is arranged at the front end opening of the outer air duct and is coaxial with the inner air duct and the outer air duct; the inner wind barrel is taken as a center, a plurality of outer ring swirl blades are distributed in an annular array, the inner end face is connected with the outer circumferential face of the inner wind barrel, the outer end face is connected with the inner circumferential face of the mounting ring, an annular wind channel is formed between the outer circumferential face of the mounting ring and the inner circumferential face of the outer wind barrel, and the deflection directions of the inner ring swirl blades and the outer ring swirl blades are the same; the primary fuel pipe is axially arranged and is in butt joint with the through hole; a plurality of secondary fuel pipes which are axially arranged in the inner air duct and are circularly arrayed by taking the blunt disk as a center, wherein the front end of each secondary fuel pipe extends out of the inner air duct and is provided with a nozzle, and the nozzle is positioned in the head cover; a plurality of tertiary fuel pipes which are axially arranged in the mounting ring and are circularly arrayed by taking the inner air duct as a center, and the front ends of the tertiary fuel pipes extend out of the head cover and incline and shrink towards the central axis of the burner; a suspension bracket is arranged on the inner wall of the outer air cylinder corresponding to the tertiary fuel pipe, the tertiary fuel pipe can axially move, and the distance between a nozzle arranged at the front end of the tertiary fuel pipe and the front end surface of the head cover is less than or equal to 300mm; the blunt disk, the inner ring swirl vane, the outer ring swirl vane and the mounting ring are arranged on a plane, and the front ends of the first, second and third fuel pipes are respectively provided with a flow valve.

2. The multi-stage swirl burner of claim 1, wherein: the inner ring swirl blades and the outer ring swirl blades are of flat plate structures, and the included angle between the outer ring swirl blades and the axis is larger than that between the inner ring swirl blades and the axis.

3. The multi-stage swirl burner of claim 2, wherein: the included angle between the outer ring swirl vane and the axis is 35-50 degrees, and the included angle between the inner ring swirl vane and the axis is 30-40 degrees.

4. The multi-stage swirl burner of claim 1, wherein: the diameter of the primary fuel pipe nozzle is gradually expanded forward, and the material is sprayed forward axially.

5. The multi-stage swirl burner of claim 4, wherein: the primary fuel pipe nozzle divergence angle is 35-65 degrees.

6. The multi-stage swirl burner of claim 1, wherein: the front end of the secondary fuel pipe is uniformly provided with a plurality of nozzle openings in the circumferential direction, the secondary fuel pipe sprays materials outwards along the radial direction, and the radius of the nozzle opening of the secondary fuel pipe is 2-5mm.

7. The multi-stage swirl burner of claim 1, wherein: the included angle between the three-stage fuel pipe nozzle and the central axis is 145-155 degrees.

8. The multi-stage swirl burner of claim 1, wherein: the primary fuel pipe has an inner diameter of 10-20mm and a wall thickness of 1-2mm; the inner diameter of the secondary fuel pipe is 8-12mm, and the wall thickness is 1-2mm; the inner diameter of the three-stage fuel pipe is 5-12mm, and the wall thickness is 1-2mm; the diameter of the inner wind barrel is 380-430mm; the distance between the outer peripheral surface of the mounting ring and the inner peripheral surface of the outer air duct is 40-60mm; the hood shrinks by 155-165 degrees.