CN116293686A

CN116293686A - Burner with adjustable flame

Info

Publication number: CN116293686A
Application number: CN202310528219.8A
Authority: CN
Inventors: 刘永才; 王绥德; 张龙; 高鲁斌; 黄世峰
Original assignee: Shenzhen Jiayuntong Electronics Co Ltd
Current assignee: Shenzhen Jiayuntong Electronics Co Ltd
Priority date: 2023-05-11
Filing date: 2023-05-11
Publication date: 2023-06-23

Abstract

The invention relates to the technical field of burners, and discloses a burner with adjustable flame, which comprises a burner air inlet section and a gas pipe, wherein the burner air inlet section and the gas pipe are coaxially arranged: the air inlet section of the burner is sequentially and coaxially provided with a peripheral air pipe and a fire gathering cover; the peripheral diameter of the fire gathering cover is smaller than the inner diameter of the peripheral air pipe, and the fire gathering cover can slide in the peripheral air pipe; the burner also comprises an adjusting device, wherein the adjusting device is connected with the fire gathering cover and is used for adjusting the relative position of the fire gathering cover and the peripheral air pipe. The invention realizes the proportioning of secondary air by adjusting the position of the fire gathering cover, and simultaneously realizes the relative positions of the burner nozzle and the fire gathering cover outlet, thereby realizing the change of flame form, adapting to reasonable air distribution under different working conditions and enhancing the adaptability to different hearths. The time of the operation of the field technology and after-sales personnel is greatly reduced, and the time efficiency of the whole burner debugging period is improved, so that the waste of personnel is reduced.

Description

Burner with adjustable flame

Technical Field

The invention belongs to the technical field of burners, and particularly relates to a burner with adjustable flame.

Background

The gas burner has the advantages of safety, high efficiency, simple operation and the like, is core equipment for providing heat energy for an industrial boiler, the combustion head of the burner is a key core component of the whole burner, the component is used for mixing fuel gas and combustion air and conducting organized combustion, the structural type of the component determines the reliability and stability of the combustion process, and the speed and temperature distribution of the whole combustion area, and the key factors influence the smoke emission.

The boiler or the heating furnace type is affected by the use condition and the application function, the type and the hearth type are different, the process structures of different factories are different, and the common boiler or the heating furnace has a plurality of smoke range types such as single return stroke, two return strokes, three return strokes and the like, and even the heating furnace of one manufacturer also has a vacuum phase-change furnace, a water jacket furnace, a fire tube furnace and the like. Such a large number of types of hearths, the heat exchange pattern and the radiant section of which are not uniform, results in a burner that needs to be matched to a wide variety of types of flames. However, the flame form of the existing burner is unchanged when the existing burner is operated, and the same burner is used in different furnaces and is limited to different use effects.

Patent CN 204829918U proposes a secondary air adjusting device, which realizes secondary air proportion by adjusting the distance between a flame stabilizing disc and an adjusting cylinder, and the adjusting mode solves the problem of reasonable air distribution under different working conditions, but does not provide a specific adjusting mechanism, and has limited adjusting effect on flame form.

Therefore, there is a need for a flame cover structure that can adjust the burner head to achieve dynamic adjustment of flame morphology.

Disclosure of Invention

The purpose of the invention is that: aims to provide a burner with adjustable flame, which is used for solving the problems that the flame form of the burner cannot be changed and the burner cannot be suitable for various hearths in the prior art.

In order to achieve the technical purpose, the invention adopts the following technical scheme:

the utility model provides a combustor of adjustable flame, includes combustor air inlet section and gas pipe, combustor air inlet section and the coaxial setting of gas pipe:

the air inlet section of the burner is sequentially and coaxially provided with a peripheral air pipe and a fire gathering cover; the peripheral diameter of the fire gathering cover is smaller than the inner diameter of the peripheral air pipe, and the fire gathering cover can slide in the peripheral air pipe; the burner also comprises an adjusting device, wherein the adjusting device is connected with the fire gathering cover and is used for adjusting the relative position of the fire gathering cover and the peripheral air pipe.

Further, a gear shaft mounting seat is arranged on the air inlet section of the combustor; the gear shaft mounting seat is provided with a gear shaft hole; the axis of the gear shaft hole is perpendicular to the axis of the air inlet section of the burner; the adjusting device comprises an electric servo, a coupler, an adjusting gear shaft and a gear shaft bearing which are sequentially arranged from top to bottom; the electric servo comprises an electric servo rotating shaft; one end of the adjusting gear shaft, which is far away from the coupler, is provided with an adjusting gear, and the other end of the adjusting gear shaft sequentially penetrates through the gear shaft hole, the gear shaft bearing and the coupler; the adjusting gear shaft is in clearance fit with the gear shaft hole; the electric servo rotating shaft and the adjusting gear shaft are sleeved in the coupler to realize coaxial same-frequency rotation;

the fire gathering cover comprises a gear bar pull rod and a fire gathering cover body; one end of the gear bar pull rod is connected with the fire gathering cover body, and the other end of the gear bar pull rod is matched with the adjusting gear.

Further, one end of the gear bar pull rod, which is close to the adjusting gear, is provided with a gear bar, and the gear bar can be in matched linkage with the adjusting gear.

Further, a gear rack sliding rail is further arranged in the middle of the gear rack pull rod; the middle part of the gear bar pull rod is sleeved in the gear bar slide rail, and the gear bar pull rod is in clearance fit with the gear bar slide rail.

Further, peripheral air pipe limiting grooves are uniformly formed in the tail ends of the peripheral air pipes; fire gathering cover limiting blocks are uniformly arranged on the fire gathering cover body at positions corresponding to the peripheral air pipe limiting grooves; the fire gathering cover limiting block is positioned in the peripheral air pipe limiting groove, and the fire gathering cover limiting block and the peripheral air pipe limiting groove are in clearance fit.

Further, the fire gathering cover also comprises a fire gathering cover contraction section; the fire gathering cover contraction section is arranged at one end of the fire gathering cover far away from the peripheral air pipe, the aperture of one end of the fire gathering cover contraction section close to the fire gathering cover is larger than that of one end of the fire gathering cover contraction section far away from the fire gathering cover, and the aperture of the fire gathering cover contraction section is gradually changed.

Further, the gas pipe is provided with a flame stabilizing disc which is positioned at the gas outlet end of the flame gathering cover; the flame stabilizing disc is provided with a conical expansion section of the flame stabilizing disc.

Further, the flame stabilizing disc is provided with a swirler.

Further, a pointer is arranged on the adjusting gear shaft and is positioned between the coupler and the gear shaft bearing; the surface of the gear shaft mounting seat is carved with a dial, and the dial is positioned in the direction pointed by the pointer.

Further, the electric servo is externally connected with the burner controller, a position database of fire gathering covers corresponding to different hearth sizes is arranged in the burner controller, and the proper positions of the fire gathering covers can be adjusted according to the different hearth sizes.

The invention adopting the technical scheme has the following advantages:

(1) The position of the fire gathering cover can be adjusted, which is beneficial to adjusting the flame form;

(2) The adaptability of the burner to different hearth types is enhanced;

(3) The secondary air ratio can be adjusted, so that the mixing of fuel gas and air is facilitated, and the emission is reduced;

(4) The time of the operation of the field technology and after-sales personnel is greatly reduced, and the time efficiency of the whole burner debugging period is improved, so that the waste of personnel is greatly reduced.

Drawings

The invention can be further illustrated by means of non-limiting examples given in the accompanying drawings;

FIG. 1 is a schematic view of a burner for automatically adjusting flame according to the present invention;

FIG. 2 is a perspective view of a burner for automatically adjusting flame in accordance with the present invention;

FIG. 3 is a partial schematic view of an adjusting gear and rack bar pull rod in an automatically flame adjusting burner of the present invention.

The main reference numerals are as follows:

a burner air inlet section 1; a gear shaft mount 11; a gear shaft hole 12; a dial 13; a mounting flange 2; a peripheral air tube 3; a peripheral air tube limit groove 31; a fire gathering cover 4; a fire-gathering cover limiting block 41; a fire hood contraction section 42; an adjusting gear 5; an adjustment gear shaft 51; a pointer 52; a gear strip 6; a rack bar lever 61; a gear rack slide rail 62; an electric servo 7; an electric servo rotation shaft 71; a coupling 72; gear shaft bearings 73; a gas pipe 8; a flame stabilizing plate 81; a flame stabilizing disk conical expansion section 82; a burner controller 9.

Detailed Description

The present invention will be described in detail below with reference to the drawings and the specific embodiments, wherein like or similar parts are designated by the same reference numerals throughout the drawings or the description, and implementations not shown or described in the drawings are in a form well known to those of ordinary skill in the art. In addition, directional terms such as "upper", "lower", "top", "bottom", "left", "right", "front", "rear", etc. in the embodiments are merely directions with reference to the drawings, and are not intended to limit the scope of the present invention.

As shown in fig. 1-3, a flame-adjustable burner comprises a burner air inlet section 1 and a gas pipe 8, wherein the burner air inlet section 1 and the gas pipe 8 are coaxially arranged;

the air inlet section 1 of the burner is sequentially and coaxially provided with a peripheral air pipe 3 and a fire gathering cover 4; the installation flange 2 is arranged at the joint of the peripheral air pipe 3 and the air inlet section 1 of the burner, and the installation flange 2 is convenient for installing the burner into a combustion hearth and is convenient for disassembly and maintenance; the peripheral diameter of the fire gathering cover 4 is smaller than the pipe inner diameter of the peripheral air pipe 3, the fire gathering cover 4 is partially arranged in the peripheral air pipe 3, and the fire gathering cover 4 can slide in the peripheral air pipe 3; the burner also comprises an adjusting device, wherein the adjusting device is connected with the fire gathering cover 4 and is used for adjusting the relative position of the fire gathering cover 4 and the peripheral air pipe 3 so as to change the shape of combustion flame. The adjusting device can be a manual adjusting device, and the tool is used for manually rotating or moving the fire gathering cover 4 to adjust the position and the angle of the fire gathering cover to control the flame shape. The flame-gathering cover 4 can also be a hydraulic or pneumatic adjusting device, and the position and the angle of the flame-gathering cover 4 can be adjusted through a hydraulic system or a pneumatic system to control the flame form. The adjusting device can also be an electric adjusting device, and the position and the angle of the fire gathering cover 4 can be automatically adjusted through a motor and a control system, so that the flame form is controlled.

When the burner is used, the gas pipe 8 supplies gas to the burner, the air inlet section 1 of the burner and the peripheral air pipe 3 supply air to the burner, and finally the gas and the air are mixed in the fire gathering cover 4 and burnt. The flame-holding cover 4 is an important component in the burner, which can influence the combustion efficiency and flame morphology of the burner. When the fire gathering cover 4 is close to the combustion head, combustion gas can be burnt in a smaller space, and more concentrated flame is generated; when the fire gathering cover 4 is far away from the combustion head, combustion gas can be burnt in a larger space, and more diffuse flame is generated. Thus, the shape and size of the flame can be controlled by adjusting the position of the flame holding cover 4.

Compared with the prior art, the flame form of the burner designed by the invention can be adjusted: the form of the combustion flame can be changed by adjusting the relative positions of the fire gathering cover 4 and the peripheral air pipe 3, so that the flame can be adjusted, and different combustion requirements can be met. The operation is simple and convenient: the adjusting device of the burner is connected with the fire gathering cover 4, and can be conveniently adjusted without professional skills. The installation and maintenance are convenient: the mounting flange 2 of the burner is convenient for mounting the burner in a combustion hearth and is convenient for disassembly and maintenance. The combustion efficiency is high: by adjusting the flame form, the combustion can be more sufficient, and the combustion efficiency is improved. The application range is wide: the burner can be applied to various industrial combustion equipment, such as boilers, industrial furnaces and the like, and has higher applicability.

In some embodiments, the air inlet section 1 of the burner is provided with a gear shaft mounting seat 11; a gear shaft hole 12 is formed in the center of the gear shaft mounting seat 11; for the adjusting gear shaft 51 to pass through, the axis of the gear shaft hole 12 is perpendicular to the axis of the air inlet section 1 of the burner; the adjusting device comprises an electric servo 7, a coupler 72, an adjusting gear shaft 51 and a gear shaft bearing 73 which are sequentially arranged from top to bottom; the electric servo 7 comprises an electric servo rotating shaft 71; one end of the adjusting gear shaft 51, which is far away from the coupler 72, is provided with an adjusting gear 5, and the other end sequentially passes through the gear shaft hole 12, the gear shaft bearing 73 and the coupler 72; the adjusting gear shaft 51 is in clearance fit with the gear shaft hole 12; the electric servo rotating shaft 71 and the adjusting gear shaft 51 are sleeved in the coupler 72, so that coaxial same-frequency rotation is realized.

The fire gathering cover 4 comprises a gear bar pull rod 61 and a fire gathering cover 4 body; one end of the gear bar pull rod 61 is connected with the fire gathering cover contraction section 42, and the other end is matched with the adjusting gear 5. In some embodiments, the end of the gear bar pull rod 61 near the adjusting gear 5 is provided with a gear bar 6, and the gear bar 6 can be matched and linked with the adjusting gear 5.

According to the flame-adjustable burner, the gear shaft mounting seat 11 and the adjusting device are arranged, so that the relative positions of the flame gathering cover 4 and the peripheral air pipe 3 can be accurately adjusted, and the form of combustion flame is changed, and the flame-adjustable burner is suitable for different combustion working conditions and industrial production requirements. Specifically, when it is necessary to adjust the flame height, width, color, shape, etc., the position of the flame-gathering cover 4 can be changed by adjusting the rotation of the gear shaft 51, thereby adjusting the flame shape.

In operation, the electric servo shaft 71 is connected to the adjustment gear shaft 51 via the coupling 72, and when the electric servo 7 is in operation, it drives the adjustment gear shaft 51 in the coupling 72 to rotate. One end of the gear bar pull rod 61 is connected with the fire gathering cover 4 body, and the other end is connected with the adjusting gear 5 through the gear bar 6. When the electric servo rotating shaft 71 rotates, the adjusting gear shaft 51 drives the adjusting gear 5 to further drive the gear bar pull rod 61 and the fire gathering cover 4 to correspondingly move, so that the relative position of the fire gathering cover 4 and the peripheral air pipe 3 is changed, and the flame shape is changed. Meanwhile, the clearance fit between the gear shaft and the gear shaft hole 12 can reduce abrasion, and long-term stable operation of the combustor is ensured.

The burner air inlet section 1, the peripheral air pipe 3 and the fire gathering cover 4 are combined to form an air circulation channel; the fuel gas enters the burner from the fuel gas pipe 8, and the fuel gas pipe 8 guides the fuel gas to the boiler hearth; the boiler and the burner are installed through the installation flange 2;

in the running or debugging process of the burner, the electric servo 7 is controlled to realize the rotation of the electric servo rotating shaft 71 and drive the coupler 72 and the adjusting gear shaft 51 at the other end of the coupler 72 to coaxially rotate at the same frequency; the coupling 72 compensates for misalignment between the shafts due to manufacturing and mounting inaccuracies, deformation during operation, thermal expansion, and the like, and also mitigates shock and absorbs vibration.

The adjusting gear shaft 51 rotates to drive the adjusting gear 5 to rotate, and the gear strip 6 meshed and linked with the adjusting gear 5 drives the gear strip pull rod 61 to move along the axial direction of the air inlet section 1 of the burner, and the fire collecting cover 4 fixed at the other end of the gear strip pull rod 61 moves along the axial direction of the air inlet section 1 of the burner at the moment, so that the position adjustment of the fire collecting cover 4 is realized; the electric servo 7 has different rotation directions, so that the flame gathering cover 4 can axially move in a direction far away from or close to the air inlet section, and the form of combustion flame is adjusted.

In some embodiments, a gear rack sliding rail 62 is further disposed at the middle position of the gear rack pull rod 61; the middle part of the gear bar pull rod 61 is sleeved in the gear bar slide rail 62, and the gear bar pull rod 61 and the gear bar slide rail 62 are in clearance fit. When the adjusting gear 5 is driven by the adjusting gear shaft 51, the gear bar pull rod 61 is driven to move horizontally, and the sliding is smoother due to the fact that the middle of the gear bar pull rod 61 is sleeved in the gear bar sliding rail 62, and the sliding direction can be ensured to be the horizontal direction. The middle part of the gear bar pull rod 61 is sleeved in the gear bar slide rail 62, so that the gear bar pull rod 61 can be prevented from loosening or deviating from the position in the moving process, the gear bar pull rod 61 is limited to move only along the axial direction, the falling off of the fire gathering cover 4 can not occur in the adjusting process, and the engagement failure of the adjusting gear 5 and the gear bar 6 is avoided.

Specifically, when the electric servo 7 rotates, the adjusting gear 5 also rotates, so that the gear bar pull rod 61 is driven to slide left and right through the gear bar slide rail 62, and the fire gathering cover 4 also changes the relative position. The clearance fit of the gear rack slide rail 62 can ensure the stable sliding of the gear rack pull rod 61, reduce friction and abrasion with the gear rack slide rail 62, simultaneously be favorable for ensuring the fit precision of the gear rack pull rod 61 and the adjusting gear 5, and improve the adjusting precision and reliability of the burner.

In some embodiments, peripheral air pipe limiting grooves 31 are uniformly arranged at the tail end of the peripheral air pipe 3; fire gathering cover limiting blocks 41 are uniformly arranged on the fire gathering cover 4 body at positions corresponding to the air pipe limiting grooves; the fire gathering cover limiting block 41 is positioned in the peripheral air pipe limiting groove 31, and the two are in clearance fit. Because the fire gathering cover limiting block 41 is positioned in the peripheral air pipe limiting groove 31, no matter the fire gathering cover 4 moves forwards or backwards under the drive of the gear bar pull rod 61, the distance range of the peripheral air pipe limiting groove 31 cannot be exceeded. On the one hand, the flame-holding hood 4 is prevented from rotating in the circumferential direction, and on the other hand, the adjustment range of the flame-holding hood 4 in the axial direction is defined.

Such a design may ensure that the relative position of the fire gathering cap 4 is fixed relative to the position of the peripheral air tube 3 because the clearance fit of the fire gathering cap stopper 41 and the air tube stopper groove may prevent excessive movement or rotation of the fire gathering cap 4 during use. The limiting structure can also ensure that the fire gathering cover 4 can keep proper positions under different working conditions, thereby achieving better combustion effect.

In some embodiments, the fire gathering cover 4 further includes a fire gathering cover contraction section 42, the fire gathering cover contraction section 42 is disposed at an end of the fire gathering cover 4 away from the peripheral air tube 3, an aperture of an end of the fire gathering cover contraction section 42 near the fire gathering cover 4 is larger than an end of the fire gathering cover contraction section 42 away from the fire gathering cover 4, and the aperture of the fire gathering cover contraction section 42 is gradually changed. The aperture size of the contraction section 42 of the fire gathering cover is gradually changed, so that the adjustment of flame shape can be realized, and the combustion effect of the burner is further affected. During combustion, the fuel and gas entering the combustion chamber of the burner need to pass through the contraction section 42 of the flame-gathering cover, and the fuel and gas at different positions are limited and blocked to different degrees due to different pore sizes, so that the shape, size and position of the flame are changed, and the combustion efficiency and stability are affected. Therefore, the variation in the pore size of the converging shroud constriction 42 can be used to optimize the combustion of the burner by adjusting the flame shape. When the gas enters the contracted section 42 of the flame cover from the gas pipe 8, the gas flow rate and pressure are changed due to the change of the pore size, so that the gas is diffused and focused. This diffusion and focusing action allows for a more uniform mixing of the gas and air and a high velocity jet at the outlet of the squib constriction 42, resulting in a more stable and efficient combustion. In addition, the shape of the converging shroud constriction 42 can also help the mixture achieve a better flow condition, making combustion more uniform and stable.

In some embodiments, the gas pipe 8 is provided with a flame stabilizing disc 81, and the flame stabilizing disc 81 is positioned at the air outlet end of the flame gathering cover 4; the flame stabilizing tray 81 is provided with a flame stabilizing tray conical expansion section 82. The flame stabilizing disc 81 functions to provide a stable flame pattern for the combustion gases at the outlet by resistance and diffusion. The conical expansion section of the flame stabilizing disc 81 can play a role in increasing the gas flow, and meanwhile, the gas is fully mixed in the expansion section, so that a better combustion effect is achieved. In addition, the geometry of the tapered expansion section may also be optimized for gas flow and characteristics for better stability and combustion efficiency.

In some embodiments, the flame stabilizing plate 81 is provided with a cyclone, and a cyclone wind can be formed through the cyclone, so that the mixing of air and fuel gas is promoted, and a cyclone flame is formed downstream, which is more beneficial to heat exchange of different flame areas and stabilizes the flame. In addition, before the fuel gas enters the flame stabilizing disc 81, the swirler on the flame stabilizing disc 81 can forcibly rotate the fuel gas to form a rotating fluid, so that the fuel gas and the air are better mixed, and the combustion efficiency and the stability are further improved. Meanwhile, the cyclone can also increase the residence time of the fuel gas in the flame stabilizing disc 81, so that the combustion is more sufficient, and the exhaust emission and the energy waste are reduced.

In some embodiments, the adjustment gear shaft 51 mounts a pointer 52 thereon, the pointer 52 being located between the coupler 72 and the gear shaft bearing 73; the surface of the gear shaft mounting seat 11 is carved with a dial 13 and is positioned in the direction pointed by the pointer 52, and the dial 13 is carved with the moving numerical value of the fire gathering cover 4, so that the observation and the adjustment are convenient.

The function of the setting pointer 52 and dial 13 is to provide an intuitive way to display the position of the adjustment gear shaft 51, enabling the user to more accurately control the flame size and temperature. When a user needs to change the flame size or temperature, the flame size or temperature can be adjusted by rotating the adjusting gear shaft 51, and meanwhile, the current gear shaft position can be read through the pointer 52 and the dial 13 so as to know the change condition of the flame size and temperature. The design is simple and easy to use, the flame is convenient to adjust by a user, and the working efficiency is improved.

In the invention, the flame stabilizing disc 81 arranged at the tail end of the gas pipe 8 is positioned in the flame collecting cover 4, and a secondary air channel is formed between the edge of the flame stabilizing disc 81 and the end surface of the contraction section 42 of the flame collecting cover; when the flame gathering cover 4 moves axially, the relative distance between the edge of the flame stabilizing disc 81 and the flame gathering cover contraction section 42 changes, and the passage area of the secondary air also changes at the moment, so that the secondary air is adjusted, and the adjustment is simple and convenient. The invention relates to a secondary air and flame form regulating principle, which comprises the following steps: the initial position of the flame holding cover 4, namely the zero position of the dial 13, the flame holding cover contraction section 42 and the flame stabilizing disk conical expansion section 82 are basically flush in the direction perpendicular to the axis of the flame holding cover 4; when the fire gathering cover 4 moves from the initial position to the air inlet section direction during adjustment, the passage area of secondary air is increased, the air quantity of the secondary air is increased, the secondary air direction is mainly influenced by the conical expansion section 82 of the flame stabilizing disc, short and thick flames are formed at the downstream, and the longer the moving distance is, the shorter and thicker the flames are; if the fire gathering cover 4 moves from the initial position in the direction away from the air inlet section, the passage area of the secondary air becomes larger, the air quantity of the secondary air becomes larger, the secondary air direction is mainly influenced by the fire gathering cover contraction section 42, thin and long flame is formed at the downstream, and the longer the moving distance is, the thinner and longer the flame is.

In some embodiments, the electric servo 7 is externally connected with the burner controller 9, a position database of the fire gathering cover 4 corresponding to different hearth sizes is built in the burner controller 9, and the position of the fire gathering cover 4 can be adjusted appropriately according to the different hearth sizes.

The arrangement enables the burner to be adaptively adjusted according to different hearth sizes so as to obtain the best combustion effect and energy-saving effect. Through the built-in database, the burner controller 9 can select the most suitable position of the fire gathering cover 4 according to the size of the hearth input by a user, and realize automatic adjustment through a servo motor, thereby realizing efficient, stable and reliable combustion control. Thus, the adjusting time and manpower can be saved, and the efficiency and performance of the burner can be improved.

The above description is provided for a flame-adjustable burner according to the present invention. The description of the specific embodiments is only intended to aid in understanding the method of the present invention and its core ideas. It should be noted that it will be apparent to those skilled in the art that various modifications and adaptations of the invention can be made without departing from the principles of the invention and these modifications and adaptations are intended to be within the scope of the invention as defined in the following claims.

Claims

1. The utility model provides a combustor of adjustable flame, includes combustor air inlet section (1) and gas pipe (8), combustor air inlet section (1) and gas pipe (8) coaxial setting, its characterized in that:

the burner air inlet section (1) is sequentially and coaxially provided with a peripheral air pipe (3) and a fire gathering cover (4); the peripheral diameter of the fire gathering cover (4) is smaller than the inner diameter of the peripheral air pipe (3), and the fire gathering cover (4) can slide in the peripheral air pipe (3); the burner further comprises an adjusting device, wherein the adjusting device is connected with the fire gathering cover (4) and used for adjusting the relative position of the fire gathering cover (4) and the peripheral air pipe (3).

2. A flame adjustable burner as recited in claim 1, wherein:

a gear shaft mounting seat (11) is arranged on the air inlet section (1) of the burner; the gear shaft mounting seat (11) is provided with a gear shaft hole (12); the axis of the gear shaft hole (12) is perpendicular to the axis of the air inlet section (1) of the burner; the adjusting device comprises an electric servo (7), a coupler (72), an adjusting gear shaft (51) and a gear shaft bearing (73) which are sequentially arranged from top to bottom; the electric servo (7) comprises an electric servo rotating shaft (71); one end, far away from the coupler (72), of the adjusting gear shaft (51) is provided with an adjusting gear (5), and the other end of the adjusting gear shaft (51) sequentially penetrates through the gear shaft hole (12), the gear shaft bearing (73) and the coupler (72); the adjusting gear shaft (51) is in clearance fit with the gear shaft hole (12); the electric servo rotating shaft (71) and the adjusting gear shaft (51) are sleeved in the coupler (72) to realize coaxial same-frequency rotation;

the fire gathering cover (4) comprises a gear bar pull rod (61) and a fire gathering cover (4) body; one end of the gear bar pull rod (61) is connected with the fire gathering cover (4) body, and the other end of the gear bar pull rod (61) is matched with the adjusting gear (5).

3. A flame adjustable burner as recited in claim 2, wherein:

one end of the gear bar pull rod (61) close to the adjusting gear (5) is provided with a gear bar (6), and the gear bar (6) can be matched and linked with the adjusting gear (5).

4. A flame adjustable burner as claimed in claim 3, wherein:

a gear rack sliding rail (62) is further arranged in the middle of the gear rack pull rod (61); the middle part of the gear bar pull rod (61) is sleeved in the gear bar slide rail (62), and the gear bar pull rod (61) and the gear bar slide rail (62) are in clearance fit.

5. A flame adjustable burner as recited in claim 4, wherein:

peripheral air pipe limiting grooves (31) are uniformly formed in the tail ends of the peripheral air pipes (3); fire gathering cover limiting blocks (41) are uniformly arranged on the fire gathering cover (4) body at positions corresponding to the peripheral air pipe limiting grooves (31); the fire gathering cover limiting block (41) is positioned in the peripheral air pipe limiting groove (31), and the two are in clearance fit.

6. A flame adjustable burner as recited in claim 5, wherein:

the fire gathering cover (4) also comprises a fire gathering cover contraction section (42); the fire gathering cover contraction section (42) is arranged at one end of the fire gathering cover (4) far away from the peripheral air pipe (3), the aperture of one end of the fire gathering cover contraction section (42) close to the fire gathering cover (4) is larger than that of one end of the fire gathering cover contraction section (42) far away from the fire gathering cover (4), and the aperture of the fire gathering cover contraction section (42) is gradually changed.

7. A flame adjustable burner as recited in claim 6, wherein:

the gas pipe (8) is provided with a flame stabilizing disc (81), and the flame stabilizing disc (81) is positioned at the gas outlet end of the flame gathering cover (4); the flame stabilizing disc (81) is provided with a conical expansion section (82) of the flame stabilizing disc.

8. A flame adjustable burner as recited in claim 7, wherein:

the flame stabilizing disc (81) is provided with a cyclone.

9. A flame adjustable burner as recited in claim 8, wherein:

the pointer (52) is arranged on the adjusting gear shaft (51), and the pointer (52) is positioned between the coupler (72) and the gear shaft bearing (73); the surface of the gear shaft mounting seat (11) is carved with a dial (13), and the dial (13) is positioned in the direction pointed by the pointer (52).

10. A flame adjustable burner as recited in claim 9, wherein:

the electric servo (7) is externally connected with a burner controller (9), a position database of fire gathering covers (4) corresponding to different hearth sizes is arranged in the burner controller (9), and the positions of the fire gathering covers (4) can be adjusted appropriately according to the different hearth sizes.