CN214664385U

CN214664385U - Ultra-low NOXCyclone burner

Info

Publication number: CN214664385U
Application number: CN202022689865.7U
Authority: CN
Inventors: 武学谦; 相明辉; 崔星源; 李明; 刘鹏飞; 张超群; 方永旭; 李强; 秦学堂; 李驰; 刘平
Original assignee: Yantai Longyuan Power Technology Co Ltd
Current assignee: Yantai Longyuan Power Technology Co Ltd
Priority date: 2020-11-19
Filing date: 2020-11-19
Publication date: 2021-11-09
Anticipated expiration: 2030-11-19

Abstract

The utility model relates to a combustor technical field discloses an ultralow NO_XA cyclone burner. The air conditioner comprises a central air pipe, a primary air pipe, a transition air pipe, a secondary air pipe, an air quantity adjusting device and a porous plate which are coaxially arranged from inside to outside in sequence. The transition tuber pipe and secondary air pipe are configured to the inside wind that leads to of furnace to the boiler, and the wind in the transition tuber pipe is the direct current wind, the tuber pipe is configured to the inside wind powder mixture that lets in of furnace to the boiler once, central tuber pipe is configured to the inside wind or the wind powder mixture that leads to of furnace to the boiler, still be provided with the oil gun in the central tuber pipe, air regulation device sets up in the income wind gap department of transition tuber pipe, the perforated plate sets up in the spout end of transition tuber pipe, and connectBetween the transition air pipe and the primary air pipe. The arrangement of the transition air can avoid the early mixing of the secondary air and the air-powder mixture, and ensure a reasonable air-coated powder flow field so as to solve the problems of burner burning loss, coking and NO existing when the low-ash-melting-point coal is used_XThe problem of high emission.

Description

Ultra-low NOXCyclone burner

Technical Field

The utility model relates to a combustor technical field especially relates to an ultralow NO_XA cyclone burner.

Background

A burner is a device for ejecting and mixing fuel and air (or mixing and ejecting) in a certain manner to burn, and is a device for converting a substance into heat energy by a chemical reaction of combustion. The combustor can be divided into multiple types according to the difference such as fuel, use object and application, for example, the combustor can be divided into pulverized coal burner, oil burner and gas burner according to the difference of fuel that burns, and pulverized coal burner can divide spiral-flow type and open-flow type again in two, and wherein spiral-flow type combustor is a comparatively practical novel combustor, mainly is applicable to power boiler.

At present, thermal power generation is still the main electricity generation form in China, fuel cost is the most key factor for profitability of a thermal power plant, most power plants improve enterprise benefits by adjusting coal-fired structures, and some coal-fired power plants adopt low-ash-melting-point coal for reducing operation cost due to price advantage of low-ash-melting-point coalThe coal is used as the coal quality of the furnace. However, the coal quality characteristics of low ash fusion point coal with strong dirt-staining property and short slag and easily forming a local high temperature area have larger deviation from the designed coal type, and the phenomena of burner burning loss and coking are easily caused by mixing and burning the low ash fusion point coal under the condition that the thermal parameters of the boiler such as the volume thermal load, the cross-section thermal load, the wall surface thermal load and the like are not changed, so that the flow field of the outlet of the burner is seriously deviated from the designed working condition, and the NO is caused to cause_XThe discharge amount is increased, and the safe operation of the boiler is influenced in severe cases.

Thus, there is a need for an ultra-low NO_XThe cyclone burner can solve the problems of burner burning loss and coking phenomena and NO in the furnace existing when low-ash-melting-point coal is used_XThe problem of high emission.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an ultralow NO_XThe cyclone burner can solve the problems of burner burning loss and coking phenomena and NO in the furnace existing when low-ash-melting-point coal is used_XThe problem of high emission.

As the conception, the utility model adopts the technical proposal that:

ultra-low NO_XA cyclone burner comprising:

the air-powder mixing device comprises a central air pipe, a primary air pipe, a transition air pipe and a secondary air pipe which are coaxially arranged from inside to outside in sequence, wherein the transition air pipe and the secondary air pipe are configured to introduce air into a hearth of the boiler, the air in the transition air pipe is direct-current air, a vortex generator is arranged in the secondary air pipe, the primary air pipe is configured to introduce air-powder mixtures into the hearth of the boiler, the central air pipe is configured to introduce air or air-powder mixtures into the hearth of the boiler, and an oil gun is further arranged in the central air pipe;

the porous plate is arranged at the nozzle end of the transition air pipe and is connected between the transition air pipe and the primary air pipe;

and the air quantity adjusting device is arranged at an air inlet of the transition air pipe, so that the air speed at the nozzle end of the transition air pipe is 5-18 m/s.

Furthermore, the transition air pipe and the secondary air pipe are both connected to a secondary air box, the primary air pipe is connected to an air powder pipeline for conveying an air-powder mixture, the central air pipe is communicated with the air powder pipeline through an air guide pipe, a conical separation device is arranged in the air powder pipeline, and the conical separation device is configured to separate exhaust air in the air-powder mixture into the air guide pipe.

Furthermore, an adjusting valve is further arranged in the air guide pipe and used for adjusting the flow of the exhaust air in the air guide pipe.

Furthermore, the transition air pipe and the secondary air pipe are both connected to a secondary air box, the primary air pipe is connected to an air-powder pipeline for conveying air-powder mixture, and the central air pipe is communicated with the secondary air box through an air guide pipe.

Furthermore, one end of the transition air pipe, which extends into the hearth, is provided with a frustum-shaped pipe, the small-diameter end of the frustum-shaped pipe is connected with the transition air pipe, and the included angle between the extension direction of the conical wall of the frustum-shaped pipe and the axial direction of the transition air pipe is 15-45 degrees.

Furthermore, a concentration separation device is arranged in the primary air pipe, the concentration separation device is a spindle body structure provided with a through hole in the axial direction, and the spindle body structure is sleeved at the nozzle end of the central air pipe.

Furthermore, an annular blunt body is further arranged in the primary air pipe, the annular blunt body is coaxial with the central air pipe, the spindle body structure comprises a first portion and a second portion which are connected, the outer diameter of the first portion is gradually increased along the flowing direction of air in the primary air pipe, the outer diameter of the second portion is gradually decreased, and the annular blunt body surrounds the second portion.

Further, the wall thickness of the annular blunt body close to the nozzle end of the primary air pipe is larger than that of the annular blunt body far away from the nozzle end of the primary air pipe.

Further, still be equipped with the mounting bracket on the annular blunt body, the mounting bracket can dismantle connect in the inner wall of primary air pipe.

Furthermore, a plurality of stable combustion teeth which are distributed circumferentially are also arranged at the nozzle end of the primary air pipe.

The utility model has the advantages that:

the utility model provides an ultralow NO_XThe cyclone burner comprises a central air pipe, a primary air pipe, a transition air pipe, a secondary air pipe, an air quantity adjusting device and a porous plate. The utility model discloses a boiler, including central tuber pipe, the primary air pipe, transition tuber pipe and secondary air pipe by interior and outer coaxial setting in proper order, transition tuber pipe and secondary air pipe are configured to the inside wind that leads to of furnace to the boiler, and the wind in the transition tuber pipe is the direct current wind, be provided with vortex generator in the secondary air pipe, the primary air pipe is configured to the inside wind powder mixture that lets in of furnace to the boiler, the central tuber pipe is configured to the inside wind or the wind powder mixture that leads to of furnace to the boiler, still be provided with the oil gun in the central tuber pipe, the perforated plate sets up in the spout end of transition tuber pipe, and connect between transition tuber pipe and primary air pipe, air regulation apparatus sets up in the income wind gap department of transition tuber pipe, the wind speed that makes the spout end of transition tuber pipe is 5 ~ 18 m/s. The air quantity adjusting device and the porous plate are arranged, so that the air speed at the nozzle end of the transition air pipe can be changed by adjusting the air quantity at the inlet of the transition air pipe on the premise of not damaging the reducing atmosphere of the high-temperature low-oxygen return zone, and the high-temperature return flue gas quantity and the size of the return zone of the combustor can be adjusted; the arrangement of the transition air can also adjust the respective mixing time of the transition air in the transition air duct and the air-powder mixture in the primary air duct and the respective mixing time of the transition air in the transition air duct and the secondary air in the secondary air duct, so that the premature mixing of the secondary air and the air-powder mixture is avoided, a reasonable air-coated powder flow field is ensured, and the generation amount of NOx is reduced; in addition, the arrangement of the perforated plate also enables the transition wind to be further accelerated at the nozzle end so as to realize the cooling of the nozzle of the combustor. Thus, the ultra-low NO_XThe cyclone burner can solve the problems of burner burning loss and coking phenomena and NO in the furnace existing when low-ash-melting-point coal is used_XThe problem of high emission.

Drawings

FIG. 1 shows an ultra-low NO provided by the first embodiment of the present invention_XThe structure schematic diagram of the cyclone burner;

FIG. 2 shows the ultra-low NO provided by the second embodiment of the present invention_XThe structure schematic diagram of the cyclone burner;

FIG. 3 shows the ultra-low NO provided by the third embodiment of the present invention_XThe structure schematic diagram of the cyclone burner;

FIG. 4 shows an ultra-low NO provided by the fourth embodiment of the present invention_XThe structure of the cyclone burner is shown schematically.

In the figure:

1. an oil gun; 2. a central air duct; 3. a primary air duct; 4. a transition air duct; 5. a secondary air duct; 6. a combustion stabilizing tooth; 7. a secondary air box; 8. a frustum-shaped tube; 9. a concentration separation device; 10. an annular bluff body; 11. a perforated plate; 12. an air volume adjusting device; 13. a conical separation device; 14. an air-powder duct; 15. an air guide pipe.

Detailed Description

In order to make the technical problem solved by the present invention, the technical solution adopted by the present invention and the technical effect achieved by the present invention clearer, the technical solution of the present invention will be further explained by combining the drawings and by means of the specific implementation manner. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some but not all of the elements related to the present invention are shown in the drawings.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, detachably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "left", "right", and the like are used in the orientation or positional relationship shown in the drawings only for convenience of description and simplicity of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

The technical solution of the present invention is further explained by the following embodiments with reference to the accompanying drawings.

Example one

As shown in FIG. 1, the present example provides an ultra-low NO_XThe cyclone burner comprises a central air pipe 2, a primary air pipe 3, a transition air pipe 4, a secondary air pipe 5, an air quantity adjusting device 12 and a porous plate 11. The central air pipe 2, the primary air pipe 3, the transition air pipe 4 and the secondary air pipe 5 are coaxially arranged from inside to outside in sequence, the transition air pipe 4 and the secondary air pipe 5 are configured to introduce air into a hearth of the boiler, the air in the transition air pipe 4 is direct current air, a vortex generator is arranged in the secondary air pipe 5, the primary air pipe 3 and the central air pipe 2 are configured to introduce an air-powder mixture into the hearth of the boiler, and an oil gun 1 is also arranged in the central air pipe 2; the porous plate 11 is arranged at the nozzle end of the transition air pipe 4 and is connected between the transition air pipe 4 and the primary air pipe 3; the air volume adjusting device 12 is arranged at an air inlet of the transition air duct 4, so that the air speed at the nozzle end of the transition air duct 4 is 5-18 m/s.

The air volume adjusting device 12 and the porous plate 11 are arranged, so that the air volume at the inlet of the transition air pipe 4 can be adjusted on the premise of not destroying the reducing atmosphere of the high-temperature low-oxygen backflow area, the air speed at the nozzle end of the transition air pipe 4 is changed, and the high-temperature backflow flue gas volume and the size of the backflow area of the combustor can be adjusted; furthermore, the provision of the perforated plate 11 also allows the transition wind to be further accelerated at the port end to effect cooling of the burner ports. In the present embodiment, the perforated plate 11 is annular, and the small holes are uniformly distributed along the circumferential direction of the perforated plate 11, preferably, the small holes are generally arranged in one layer to three layers along the radial direction of the perforated plate 11, and the number of the small holes of a single layer is generally 12-50.

Further, as shown in fig. 1, the transition air duct 4 and the secondary air duct 5 are both connected to the secondary air box 7, the primary air duct 3 is connected to an air powder duct 14 for conveying the air-powder mixture, the central air duct 2 is communicated with the air powder duct 14 through an air guide duct 15, a conical separation device 13 is arranged in the air powder duct 14, and the conical separation device 13 is configured to separate exhaust air in the air-powder mixture into the air guide duct 15. In particular, the conical separation device 13 is prior art, and the specific structure and operation thereof will not be described in detail herein. In the embodiment, the conical separation device 13 is made of silicon carbide material, the content of silicon carbide is not less than 65%, the conical separation device has better wear resistance and long service life, and the conical separation device 13 is arranged in the air powder pipeline 14 and mainly contacts with the air powder mixture, the ambient temperature is generally 60-120 ℃, even in individual cases, hot air is adopted for feeding powder, the ambient temperature is generally 130-200 ℃, and therefore, the silicon carbide material is completely suitable.

It can be understood that, under the arrangement, the primary air pipe 3 is filled with the air-powder mixture, the central air pipe 2 is filled with the exhaust air obtained by separation through the conical separation device 13, the concentration of the coal powder in the exhaust air is lower than that of the coal powder in the air-powder mixture, so that the concentration of the coal powder in the outer layer of the air-powder mixture is high, and the concentration of the coal powder in the inner layer of the air-powder mixture is low at the nozzle of the burner, and the arrangement can optimize the concentration and dilution separation performance of the air-powder mixture at the nozzle of the burner. Furthermore, the temperature of the recirculation zone at the outlet of the burner is often more than 1100 ℃, while the exhaust gas comes from the air-powder mixture, and the temperature of the exhaust gas is far lower than the air temperature in the secondary air pipe 5, so that the exhaust gas introduced into the central air pipe 2 can also play a role in reducing the wall temperature of the nozzle end of the central air pipe 2.

Furthermore, the transition air duct 4 is clamped between the primary air duct 3 and the secondary air duct 5, the air speed of the nozzle of the transition air duct 4 is set to be 5-18 m/s, the air speed of the nozzle of the primary air duct 3 is 14-26 m/s, the air speed of the nozzle of the secondary air duct 5 is 38-55 m/s, the transition air adopts low air speed, the form of a backflow area is not damaged, but the respective mixing time of the transition air in the transition air duct 4 and the air-powder mixture in the primary air duct 3 and the transition air in the transition air duct 4 and the secondary air in the secondary air duct 5 can be adjusted, the premature mixing of the secondary air and the air-powder mixture is avoided, a reasonable air-coated powder flow field is ensured, the generation amount of NOx is reduced, the combustor can have wide coal quality adaptability, can better adapt to low ash melting point coal, the high-load coal, the Shenhua coal and other coal types with extremely strong pollution characteristics and short slag characteristics are prevented from high-temperature backflow and entrainment near the combustor nozzle, and coking phenomenon appears at the nozzle end of the burner. Specifically, the proportion of the transitional air is small, and the proportion of the air volume of the transitional air to the air volume of the secondary air is generally 1: 3-1: 7, so that the form of a backflow area at a nozzle of the combustor cannot be damaged under the condition that the transitional air is further accelerated to be sprayed at the nozzle end.

Furthermore, an adjusting valve is arranged in the air guide pipe 15 connected with the central air pipe 2 and used for adjusting the flow of exhaust air in the air guide pipe 15. In this embodiment, the regulating valve is preferably a remote pneumatic valve or an electric regulating valve, and the regulating valve is externally connected with a DCS (distributed control system), so that the proportion of the exhaust gas entering the air duct 15 can be regulated in real time according to the actual working condition requirements, so as to meet the combustion requirements of different coal types. In addition, preferably, in this embodiment, a wear-resistant part is disposed at a contact portion of the air guide pipe 15 and the air powder duct 14, so that the problem of leakage of pulverized coal at a connection portion of the air guide pipe 15 and the air powder duct 14 due to excessive washing of the air-powder mixture can be effectively avoided. In particular, the wear part is preferably a 20mm steel plate lined with ceramic to ensure stability of the joint. Of course, in other embodiments, the material of the wear-resistant member may be silicon carbide.

In order to further optimize the combustion effect, a concentration separation device 9 is arranged in the primary air pipe 3, the concentration separation device 9 is a spindle body structure with a through hole arranged in the axial direction, and the spindle body structure is sleeved at the nozzle end of the central air pipe 2. The wind-powder mixture that flows in the primary air pipe 3 is when via this spindle structure, the great buggy granule of diameter among the wind-powder mixture is owing to inertial action, will continue to move forward along the inner wall of keeping away from central tuber pipe 2 one side of primary air pipe 3 after passing through the spindle structure, and the less buggy granule of diameter and gas are then because inertial action is less and to the gathering of one side that is close to central tuber pipe 2, it is high to form outer buggy concentration at the combustor nozzle department finally, the wind-powder mixture that inlayer buggy concentration is low.

As shown in fig. 1, an annular blunt body 10 is further arranged in the primary air pipe 3, the annular blunt body 10 is coaxial with the central air pipe 2, the spindle structure comprises a first portion and a second portion which are connected, the outer diameter of the first portion is gradually increased along the flowing direction of the air in the primary air pipe 3, the outer diameter of the second portion is gradually decreased, and the annular blunt body 10 is arranged around the second portion. Specifically, the annular blunt body 10 can be combined with a spindle body structure to form a flow field shape with thick outside and thin inside of the wind-powder mixture, and can replace a stable combustion tooth 6 structure to improve the turbulence degree of the outlet end of the combustor and strengthen combustion, which is particularly effective for poor-quality coal.

Further, the wall thickness of the annular blunt body 10 close to the nozzle end of the primary air pipe 3 is greater than that of the annular blunt body far away from the nozzle end of the primary air pipe 3. Specifically, the wall thickness of the nozzle end close to the primary air pipe 3 is large, so that a mat rolling and guiding effect can be further formed on the dense side air flow of the air-powder mixture in the primary air pipe 3, and the dense-dilute effect of the air-powder mixture in the radial direction of the nozzle of the combustor is better. In this embodiment, in order to ensure that the annular blunt body 10 can still remain undeformed for a long time under the high-temperature heat radiation inside the furnace, so as to ensure the gas flow form at the outlet of the burner, preferably, the annular blunt body 10 is cast and formed by silicon carbide, and in the circumferential direction, the annular blunt body 10 is composed of four sub blunt bodies, and a certain expansion gap is maintained between each sub blunt body, and the expansion gap is preferably 3-20 mm.

Furthermore, the annular blunt body 10 is further provided with a mounting bracket, and the mounting bracket is detachably connected to the inner wall of the primary air duct 3. Specifically, in the present embodiment, the mounting frame is a fin structure in which the outer wall of the annular blunt body 10 is arranged along the radial direction, and at least one outer fin is arranged on each sub-blunt body and detachably connected to the inner wall of the primary air duct 3, preferably, the detachable connection is a bolt connection.

As shown in fig. 1, one end of the transition air duct 4 extending into the furnace is provided with a frustum-shaped duct 8, the small-diameter end of the frustum-shaped duct 8 is connected to the transition air duct 4, and the extending direction of the conical wall of the frustum-shaped duct 8 forms an included angle of 15-45 degrees with the axial direction of the transition air duct 4. Specifically, transition tuber pipe 4 forms the node functional area together with frustum venturi tube 8, can effectively adjust the ignition point for the distribution of wind moves backward, strengthens air classification, not only can further strengthen the function of surely firing, can reduce NO by a wide margin moreover_XThe amount of formation in the initial stage of combustion. Because the air quantity of the transition air is equivalent to the isolation air with ultra-small air rate, and the transition air is direct-current air, the layer of isolation air can weaken the direct influence of the swirling air in the secondary air pipe 5 on the combustion area at the nozzle end of the primary air pipe 3, and the characteristic that the combustion area at the nozzle end of the primary air pipe 3 is long and narrow is kept.

Example two

This example discloses an ultra-low NO_XCyclone burner, ultra low NO in this example_XCyclone burner and ultra-low NO in example one_XThe difference of the cyclone burner lies in: the central air duct 2 is configured to introduce air into the furnace of the boiler, as shown in fig. 2, the transition air duct 4 and the secondary air duct 5 are both connected to the secondary air box 7, the primary air duct 3 is connected to an air-powder duct 14 for conveying an air-powder mixture, and the central air duct 2 is communicated with the secondary air box 7 through an air guide duct 15. During combustion, air is introduced from the central air pipe 2 and ignited, air-powder mixture is introduced from the primary air pipe 3, and the air-powder mixture enters the hearth of the boiler to be combusted in an annular manner at the nozzle end of the primary air pipe 3.

In addition, the ultra-low NO provided in this example_XUltra low NO in the remaining structure of the cyclone burner and in the first embodiment_XThe cyclone burners are the same and will not be described in detail herein.

EXAMPLE III

This example discloses an ultra-low NO_XCyclone burner, ultra low NO in this example_XCyclone burner and ultra-low NO in example one_XThe difference of the cyclone burner lies in: as shown in fig. 3, the nozzle end of the primary air pipe 3 is further provided with a plurality of circumferentially distributed combustion stabilizing teeth 6, and it should be particularly noted that, when low ash fusion point coal is used, the design of the burner needs to provide a reasonable backflow zone and airflow expansion angle to ensure the coal powder burnout performance and low NO_XThe performance, therefore the combustor can regard as main bluff body with surely fire ring, central dryer, guide cone etc. form certain backward flow region at combustor exit, guarantee enough big backward flow district size and reasonable initial position.

Example four

This example discloses an ultra-low NO_XCyclone burner, ultra low NO in this example_XCyclone burner and ultra-low NO in example one_XThe difference of the cyclone burner lies in: as shown in fig. 4, the transition air duct 4 and the secondary air duct 5 are both connected to the secondary air box 7, the primary air duct 3 is connected to an air-powder duct 14 for conveying air-powder mixture, and the central air duct 2 is communicated with the secondary air box 7 through an air guide duct 15. Furthermore, in order to ensure that the combustor has a reasonable backflow zone and airflow expansion angle to ensure the pulverized coal burnout performance and low NO_XThe performance, the spout end of the primary air pipe 3 is also provided with a plurality of stable combustion teeth 6 which are distributed circumferentially.

The above embodiments have been described only the basic principles and features of the present invention, and the present invention is not limited by the above embodiments, and is not departing from the spirit and scope of the present invention. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. Ultra-low NO_XA cyclone burner, comprising:

the air-powder mixing device comprises a central air pipe (2), a primary air pipe (3), a transition air pipe (4) and a secondary air pipe (5) which are coaxially arranged from inside to outside in sequence, wherein the transition air pipe (4) and the secondary air pipe (5) are configured to introduce air into a hearth of a boiler, the air in the transition air pipe (4) is direct current air, a vortex generator is arranged in the secondary air pipe (5), the primary air pipe (3) is configured to introduce air-powder mixtures into the hearth of the boiler, the central air pipe (2) is configured to introduce air or air-powder mixtures into the hearth of the boiler, and an oil gun (1) is further arranged in the central air pipe (2);

the porous plate (11) is arranged at the nozzle end of the transition air pipe (4), and is connected between the transition air pipe (4) and the primary air pipe (3);

and the air volume adjusting device (12) is arranged at the air inlet of the transition air pipe (4), so that the air speed of the nozzle end of the transition air pipe (4) is 5-18 m/s.

2. Ultra-low NO according to claim 1_XThe cyclone burner is characterized in that the transition air pipe (4) and the secondary air pipe (5) are connected to a secondary air box (7), the primary air pipe (3) is connected to an air-powder pipeline (14) for conveying air-powder mixture, the central air pipe (2) is communicated with the air-powder pipeline (14) through an air guide pipe (15), a conical separation device (13) is arranged in the air-powder pipeline (14), and the conical separation device (13) is configured to separate exhaust air in the air-powder mixture from the air-powder mixture to the air guide pipeThe air pipe (15).

3. Ultra-low NO according to claim 2_XThe cyclone burner is characterized in that an adjusting valve is further arranged in the air guide pipe (15) and used for adjusting the flow of exhaust gas in the air guide pipe (15).

4. Ultra-low NO according to claim 1_XThe cyclone burner is characterized in that the transition air pipe (4) and the secondary air pipe (5) are connected to the secondary air box (7), the primary air pipe (3) is connected to an air-powder pipeline (14) for conveying air-powder mixture, and the central air pipe (2) is communicated with the secondary air box (7) through an air guide pipe (15).

5. Ultra-low NO according to claim 1_XThe cyclone burner is characterized in that one end of the transition air pipe (4) extending into the hearth is provided with a frustum-shaped pipe (8), the small-diameter end of the frustum-shaped pipe (8) is connected with the transition air pipe (4), and the included angle between the extension direction of the conical wall of the frustum-shaped pipe (8) and the axial direction of the transition air pipe (4) is 15-45 degrees.

6. Ultra-low NO according to claim 1_XThe cyclone burner is characterized in that a concentration separation device (9) is arranged in the primary air pipe (3), the concentration separation device (9) is a spindle body structure with a through hole formed in the axial direction, and the spindle body structure is sleeved at the nozzle end of the central air pipe (2).

7. Ultra-low NO according to claim 6_XThe cyclone burner is characterized in that an annular blunt body (10) is further arranged in the primary air pipe (3), the annular blunt body (10) is coaxial with the central air pipe (2), the spindle body structure comprises a first portion and a second portion which are connected, the first portion and the second portion are arranged along the flowing direction of air in the primary air pipe (3), the outer diameter of the first portion is gradually increased, the outer diameter of the second portion is gradually decreased, and the annular blunt body (10) surrounds the second portion.

8. Ultra-low NO according to claim 7_XThe cyclone burner is characterized in that the wall thickness of the annular blunt body (10) close to the nozzle end of the primary air pipe (3) is larger than that of the annular blunt body far away from the nozzle end of the primary air pipe (3).

9. Ultra-low NO according to claim 8_XThe cyclone burner is characterized in that an installation frame is further arranged on the annular blunt body (10), and the installation frame is detachably connected to the inner wall of the primary air pipe (3).

10. Ultra-low NO according to claim 6_XThe cyclone burner is characterized in that a plurality of combustion stabilizing teeth (6) which are circumferentially distributed are further arranged at the nozzle end of the primary air pipe (3).