CN219640245U - Fuel spray gun and combustor - Google Patents

Abstract

The utility model discloses a fuel spray gun and a burner, wherein the fuel spray gun comprises a spray gun body, the spray gun body is provided with a first chamber, an ignition gas pipe and an igniter are arranged in the first chamber, the rear end of the spray gun body is provided with a natural gas pipe communicated with the ignition gas pipe, and an ignition electrode of the igniter is arranged at a nozzle of the ignition gas pipe; the outer wall of spray gun body is provided with the first air passage of intercommunication first cavity, and first air passage is used for connecting the fan, and the spout end of spray gun body is provided with a plurality of first gas passages that set up around the ignition gas pipe, and first gas passage intercommunication first cavity is and slope towards the spout direction of ignition gas pipe, and the middle part of first gas passage is provided with first shrink ring, and the flow area of first shrink ring is less than the flow area of first gas passage entry. According to the fuel spray gun provided by the embodiment of the first aspect of the utility model, oxygen can be timely supplemented for ignition fuel gas sprayed out of the fuel spray gun, so that the ignition fuel gas can be stably combusted.

Description

Fuel spray gun and combustor

Technical Field

The utility model relates to the technical field of combustors, in particular to a fuel spray gun and a combustor.

Background

In the production process of an industrial roughing system, a large amount of smelting tail gas with high availability efficiency is generated, but the smelting tail gas has low heat value, large fluctuation, unstable combustion and easy extinction, so that a great potential safety hazard is brought to production, and along with the release and implementation of environmental standards of boiler atmospheric pollutant emission standards (DB 44/765-2019) in Guangdong province, the traditional coal-fired boiler is continuously transformed to a gas-fired boiler, so that the safety problem is urgently solved. In the related art, the energy conservation and consumption reduction are realized by using the producer gas instead of anthracite as a pilot light source for burning smelting tail gas, but the combustion of the producer gas is not stable enough and has SO ₂ And the like.

In another related technology, natural gas which can generate high heat value and stably burn is adopted as a pilot source for burning smelting tail gas, but most fuel spray guns which use natural gas as ignition fuel gas in the market use natural flowing air as ignition fuel gas combustion-supporting wind to be input into the fuel spray guns, so that the flow speed of the ignition fuel gas combustion-supporting wind is slow, the speed of the ignition fuel gas spraying is faster, the ignition fuel gas combustion-supporting wind can not timely supplement oxygen for the ignition fuel gas sprayed by the fuel spray guns, the sprayed ignition fuel gas can not be completely burned, the flame sprayed by the fuel spray guns is unstable, the main fuel gas sprayed by the burner at high speed can not be fully ignited, the burning speed of the main fuel gas is lower than the speed sprayed by the main fuel gas, the phenomenon of fire removal easily occurs, and the production is dangerous.

Disclosure of Invention

The present utility model aims to solve at least one of the technical problems existing in the prior art. Therefore, the utility model provides the fuel spray gun which can timely supplement oxygen for the ignition fuel gas sprayed out of the fuel spray gun, so that the ignition fuel gas can be stably combusted.

In a second aspect, the utility model also provides a burner employing the fuel lance described above.

According to a first aspect, the present utility model proposes a fuel lance comprising: the spray gun comprises a spray gun body, wherein the spray gun body is provided with a first chamber, an ignition gas pipe and an igniter are arranged in the first chamber, the rear end of the spray gun body is provided with a natural gas pipe communicated with the ignition gas pipe, and an ignition electrode of the igniter is arranged at a nozzle of the ignition gas pipe; the outer wall of spray gun body is provided with the intercommunication first air passage of first cavity, first air passage is used for connecting the fan, the spout end of spray gun body is provided with a plurality of first gas passage, and is a plurality of first gas passage centers on ignition gas pipe sets up, first gas passage intercommunication first cavity and orientation the spout direction slope of ignition gas pipe, the middle part of first gas passage is provided with first shrink ring, the flow area of first shrink ring is less than the flow area of first gas passage entry.

The fuel spray gun according to the above embodiment of the utility model has at least the following advantageous effects:

the ignition combustion-supporting air which is conveyed into the first cavity by the fan is sprayed out through the first gas channel, under the condition that the power of the fan is unchanged, when the ignition combustion-supporting air passes through the first contraction ring, the gas flow area is reduced, the gas flow speed is increased, so that jet flow which faces the direction of the nozzle of the ignition gas pipe is formed, and the jet flow can be directly mixed with ignition gas which is sprayed out at high speed by the ignition gas pipe, so that oxygen can be provided for the ignition gas in time, the ignition gas can be fully and stably combusted, and the speed of the ignition gas for igniting main gas can be adapted to the speed of the main gas spraying when the fuel spray gun is applied to a combustor, so that the occurrence of a fire-removing phenomenon is prevented.

According to some embodiments of the utility model, the flow area of the first gas passage outlet is greater than the flow area of the first constriction ring.

According to some embodiments of the present utility model, a nozzle end of the ignition gas pipe is provided with a plurality of first spray holes and second spray holes, the first spray holes extend along an axial direction of the ignition gas pipe, a direction of the second spray holes is perpendicular to a direction of the first spray holes, and a peripheral wall of the ignition gas pipe is uniformly provided with a plurality of first through holes communicated with the first chamber.

According to some embodiments of the utility model, the lance body is provided with a flame detector integral with the ignition gas pipe in the form of a concentric sleeve, the flame detector being located in the centre of the ignition gas pipe.

In a second aspect, a burner according to the present utility model comprises the fuel lance of any one of the embodiments of the first aspect.

The burner according to the embodiment of the utility model has at least the following beneficial effects:

by adopting the fuel spray gun of the embodiment of the first aspect, the ignition combustion-supporting air which is conveyed into the first cavity by the fan is sprayed out through the first gas channel, under the condition that the power of the fan is unchanged, the gas flow speed is increased due to the fact that the gas flow area is reduced when the ignition combustion-supporting air passes through the first contraction ring, jet flow which faces the direction of the nozzle of the ignition gas pipe is formed, and the jet flow can be directly mixed with the ignition gas which is sprayed out at a high speed by the ignition gas pipe, so that oxygen can be timely provided for the ignition gas, the ignition gas can be fully and stably combusted, the speed of the ignition gas for igniting the main gas can be adapted to the speed of the main gas spraying, and the occurrence of a fire-escaping phenomenon is prevented.

According to some embodiments of the utility model, further comprising: the shell is connected with a rear cover and a fire cover, the rear cover and the fire cover are arranged oppositely, a second cavity is formed by surrounding the shell, the fire cover is provided with a central nozzle, a first nozzle and a second nozzle, the spray gun body is positioned in the center of the second cavity, and the nozzle of the ignition gas pipe is communicated with the central nozzle; the main gas channel is arranged in the second chamber, the rear cover is provided with a diversion chamber communicated with the main gas channel, the rear cover is connected with a main gas pipe communicated with the diversion chamber, and the main gas channel is communicated with the first nozzle; the main combustion-supporting air channel is arranged in the second cavity, the shell is provided with a second air channel communicated with the main combustion-supporting air channel, the second air channel is used for being connected with a fan, and the main combustion-supporting air channel is communicated with the second nozzle.

According to some embodiments of the utility model, the spray gun body is mounted to the rear cover, the spray gun body extends through the second chamber, the air inlet end of the spray gun body is located outside the shell, the first air channel is arranged at the air inlet end of the spray gun body, a flame detector is arranged in the spray gun body, and a viewing port of the flame detector extends out of the air inlet end of the spray gun body.

According to some embodiments of the utility model, the lance body, the main gas passage and the main combustion air passage are arranged in the second chamber from the center to the outside in sequence, and the main gas passage and the main combustion air passage are all arranged around the lance body.

According to some embodiments of the utility model, the main gas channel comprises a second gas channel, an outlet of the second gas channel is communicated with the first nozzle, a middle part of the second gas channel is provided with a second contraction ring, a flow area of the second contraction ring is smaller than that of an inlet of the second gas channel, the main combustion air channel comprises a third gas channel, an outlet of the third gas channel is communicated with the second nozzle, and a middle part of the third gas channel is provided with a third contraction ring, and a flow area of the third contraction ring is smaller than that of an inlet of the third gas channel.

According to some embodiments of the utility model, the flow area of the second gas passage outlet is greater than the flow area of the second constriction ring, and the flow area of the third gas passage outlet is greater than the flow area of the third constriction ring.

Additional aspects and advantages of the utility model will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the utility model.

Drawings

The foregoing and/or additional aspects and advantages of the utility model will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic illustration of the construction of a fuel lance according to some embodiments of the present utility model;

FIG. 2 is a schematic partial structural view of a fuel lance according to some embodiments of the present utility model;

FIG. 3 is a schematic view of a burner in accordance with some embodiments of the utility model;

FIG. 4 is a schematic partial structure of a burner according to some embodiments of the utility model.

Wherein, the reference numerals:

a spray gun body 100; a first chamber 110; an ignition gas pipe 120; a first nozzle hole 121; a second nozzle hole 122; a natural gas pipe 130; an igniter 140; a first air passage 150; a first gas passage 160; a first shrink ring 161; a first through hole 170; a flame detector 180;

a housing 200; a second chamber 210; a second air passage 220;

a rear cover 300; a diversion chamber 310; a main gas pipe 320;

a fire cover 400; a center spout 410; a first spout 420; second spout 430;

a main gas channel 500; a second gas channel 510; a second constriction ring 511; a second through hole 520;

a main combustion air passage 600; a third gas channel 610; a third shrink ring 611.

Detailed Description

Embodiments of the present utility model are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the utility model.

In the description of the present utility model, it should be understood that references to orientation descriptions such as upper, lower, front, rear, left, right, etc. are based on the orientation or positional relationship shown in the drawings, are merely for convenience of description of the present utility model and to simplify the description, and do not indicate or imply that the apparatus or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present utility model.

In the description of the present utility model, a number means one or more, a number means two or more, and greater than, less than, exceeding, etc. are understood to not include the present number, and above, below, within, etc. are understood to include the present number. The description of the first and second is for the purpose of distinguishing between technical features only and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present utility model, unless explicitly defined otherwise, terms such as arrangement, installation, connection, etc. should be construed broadly and the specific meaning of the terms in the present utility model can be reasonably determined by a person skilled in the art in combination with the specific contents of the technical scheme.

Referring to fig. 1 and 2, a fuel spray gun according to the present utility model includes a spray gun body 100, the spray gun body 100 is provided with a first chamber 110, an ignition gas pipe 120 and an igniter 140 are provided in the first chamber 110, a natural gas pipe 130 communicating with the ignition gas pipe 120 is provided at the rear end of the spray gun body 100, and an ignition electrode of the igniter 140 is provided at a nozzle of the ignition gas pipe 120; the outer wall of the spray gun body 100 is provided with a first air channel 150 communicated with the first chamber 110, the first air channel 150 is used for being connected with a fan, the nozzle end of the spray gun body 100 is provided with a plurality of first gas channels 160 which are arranged around the ignition gas pipe 120, the first gas channels 160 are communicated with the first chamber 110 and incline towards the nozzle direction of the ignition gas pipe 120, the middle part of the first gas channels 160 is provided with a first contraction ring 161, and the flow area of the first contraction ring 161 is smaller than that of the inlet of the first gas channels 160.

It can be understood by those skilled in the art that the catalytic combustion of natural gas can play an irreplaceable role in the heat supply, food industry, chemical industry and kiln, partial metallurgical industry and agriculture due to the stability of combustion, complete combustion and near zero pollution, therefore, the utility model preferably adopts natural gas as ignition gas to provide ignition source for the combustion of smelting tail gas, and achieves the effects of igniting the smelting tail gas and stabilizing the combustion of the smelting tail gas by utilizing the high heat value, stable combustion, low fuel consumption and flame length as the same as that of a torch when the natural gas is combusted.

It will be appreciated that when the ignition source is provided for the combustion of the smelting tail gas as the main gas, the natural gas is used as the ignition gas and is input into the ignition gas pipe 120 through the natural gas pipe 130, the ignition combustion-supporting air which is conveyed into the first chamber 110 by the fan is sprayed out through the first gas channel 160, under the condition that the fan power is unchanged, when the ignition combustion-supporting air passes through the first contraction ring 161, the gas flow speed is increased due to the reduced gas flow area, so that jet flow towards the direction of the nozzle of the ignition gas pipe 120 is formed, and the jet flow can be directly mixed with the natural gas sprayed out at a high speed by the ignition gas pipe 120, so that oxygen is provided for the natural gas in time, so that the natural gas is fully and stably combusted to provide the ignition source, and the speed of the ignition source for igniting the smelting tail gas can be adapted to the speed of the spraying of the smelting tail gas, so as to prevent the occurrence of the fire-off phenomenon.

Referring to fig. 2, according to some embodiments of the utility model, the flow area of the outlet of the first gas channel 160 is greater than the flow area of the first constriction ring 161. It will be appreciated that the flow rates of the ignition combustion air ejected from the fuel guns using different fuels may be different, so that the flow rate of the ignition combustion air may be controlled by adjusting the flow area of the outlet of the first gas channel 160, and in some embodiments, the flow area of the outlet of the first gas channel 160 may be smaller than or equal to the flow area of the first contraction ring 161, so as to ensure that the flow rate of the ignition combustion air can adapt to the flow rate of the ignition combustion air according to the actual situation.

Referring to fig. 1 and 2, the nozzle end of the ignition gas pipe 120 is provided with a plurality of first injection holes 121 and second injection holes 122, the first injection holes 121 extending along the axial direction of the ignition gas pipe 120, the second injection holes 122 being oriented perpendicular to the first injection holes 121. It can be appreciated that by arranging the first nozzle holes 121 and the second nozzle holes 122 in a plurality of directions perpendicular to each other, the diffusion area of the ignition gas can be increased, so that the ignition gas can be mixed with the ignition combustion-supporting air more easily, the combustion area of the ignition gas can be enlarged while the ignition gas can be fully and stably combusted, and then when the fuel spray gun is applied to a burner, the ignition gas can fully and quickly ignite the main gas, so that the main gas injected at a high speed can be fully combusted, and the fire-escaping phenomenon caused by that the combustion speed of the main gas is smaller than the injection speed is avoided.

Referring to fig. 1 and 2, according to some embodiments of the present utility model, the outer circumferential wall of the ignition gas pipe 120 is uniformly provided with a plurality of first through holes 170 communicating with the first chamber 110. It will be appreciated that the ignition combustion air enters the first chamber 110 through the first air passage 150, and the high-speed air flow generated by the ignition gas flowing at a high speed in the ignition gas pipe 120 can bring part of the ignition combustion air into the ignition gas pipe 120 through the first through hole 170, so that the ignition gas and the ignition combustion air are primarily premixed, thereby ensuring that the ignition gas can obtain sufficient oxygen for combustion.

Referring to fig. 1 and 2, according to some embodiments of the present utility model, a spray gun body 100 is provided with a flame detector 180, the flame detector 180 and an ignition gas pipe 120 are integrated in a concentric sleeve form, the flame detector 180 is located at the center of the ignition gas pipe 120, and the flame detector 180 is used for detecting a combustion condition in real time according to a combustion characteristic of flame, so as to ensure normal operation. In some embodiments, the fuel spray gun is further provided with a control circuit, the control circuit comprises a flameout control circuit, the flameout control circuit is connected with a gas electric control valve for controlling the supply of ignition gas, the flame detector 180 is connected with the control circuit through an electric wire, when the combustion flame formed on the outer side of the flame detector 180 is flameout due to the poor supply of the ignition gas or the blockage of a flow path of the ignition gas pipe 120, and the like, the flame detector 180 transmits a flameout signal to the flameout control circuit, and then the flameout control circuit controls the gas electric control valve to be closed so as to cut off the supply of the ignition gas.

According to the burner provided by the utility model, the fuel spray gun comprises any one of the embodiments, and the burner adopts all the technical schemes, so that the burner has the same beneficial effects and is not repeated herein.

Referring to fig. 3, a burner according to the present utility model further includes a housing 200, a main gas passage 500, and a main combustion air passage 600. The shell 200 is connected with a rear cover 300 and a fire cover 400 which are oppositely arranged, the shell 200, the rear cover 300 and the fire cover 400 are surrounded with a second chamber 210, the fire cover 400 is provided with a central nozzle 410, a first nozzle 420 and a second nozzle 430, the spray gun body 100 is positioned at the center of the second chamber 210, and the nozzle of the ignition gas pipe 120 is communicated with the central nozzle 410, so that the ignition gas pipe 120 can ignite the ignition gas at the central nozzle 410 to form an ignition source. The main gas passage 500 is disposed in the second chamber 210, the rear cover 300 is provided with a flow dividing chamber 310 communicating with the main gas passage 500, the rear cover 300 is connected with a main gas pipe 320 communicating with the flow dividing chamber 310, the main gas passage 500 is communicated with the first nozzle 420, and main gas can be delivered into the flow dividing chamber 310 through the main gas pipe 320 and then is input into the main gas passage 500 and is injected to the outside through the first nozzle 420 at a high speed. The main combustion air channel 600 is disposed in the second chamber 210, the housing 200 is provided with a second air channel 220 communicated with the main combustion air channel 600, the second air channel 220 is connected with a fan, the main combustion air channel 600 is communicated with the second nozzle 430, and the main combustion air can be conveyed into the main combustion air channel 600 through the second air channel 220 and is mixed with the main fuel gas from the outside through the second nozzle 430, so that oxygen is provided for the combustion of the main fuel gas.

Referring to fig. 3, according to some embodiments of the present utility model, the spray gun body 100 is mounted to the rear cover 300, the spray gun body 100 extends through the second chamber 210, the air inlet end of the spray gun body 100 is located outside the housing 200, the first air passage 150 is provided at the air inlet end of the spray gun body 100, the flame detector 180 is provided in the spray gun body 100, and the viewing port of the flame detector 180 extends out of the air inlet end of the spray gun body 100.

Referring to fig. 3, according to some embodiments of the present utility model, the lance body 100, the main gas passage 500 and the main combustion air passage 600 are disposed in the second chamber 210 from the center to the outside, and the main gas passage 500 and the main combustion air passage 600 are disposed around the lance body 100.

Referring to fig. 3 and 4, according to some embodiments of the present utility model, the main gas passage 500 includes a second gas passage 510, an outlet of the second gas passage 510 communicates with the first nozzle 420, a second constriction ring 511 is provided at a middle portion of the second gas passage 510, a flow area of the second constriction ring 511 is smaller than a flow area of an inlet of the second gas passage 510, and a flow area of an outlet of the second gas passage 510 is larger than a flow area of the second constriction ring 511. The main combustion air channel 600 includes a third air channel 610, an outlet of the third air channel 610 is communicated with the second nozzle 430, a third contraction ring 611 is disposed in the middle of the third air channel 610, a flow area of the third contraction ring 611 is smaller than a flow area of an inlet of the third air channel 610, and a flow area of an outlet of the third air channel 610 is larger than a flow area of the third contraction ring 611.

It will be appreciated that the flow rates of the main fuel gas ejected from the burners using different fuels are different, if the main combustion air cannot timely supplement oxygen to the main fuel gas, so that the main fuel gas cannot be sufficiently combusted, there is a risk of fire loss, so that the flow rates of the main fuel gas and the main combustion air can be controlled by adjusting the flow areas of the inlets and outlets of the second gas channel 510 and the third gas channel 610 and the flow areas of the second constriction ring 511 and the third constriction ring 611, so that fire loss caused by too fast flow rate of the main fuel gas can be avoided, and the flow rate of the main combustion air is adapted to the flow rate of the main fuel gas, thereby ensuring that sufficient oxygen can be provided to the main fuel gas.

Referring to fig. 3, according to some embodiments of the present utility model, the second air passage 220 is provided with two air inlets, one of which is connected with an air line capable of inputting combustion air, and the other of which is connected with an air return line for connecting with an exhaust gas treatment device of a boiler, and part of the boiler flue gas can be extracted and fed into the second air passage 220, so that the boiler flue gas and the combustion air are mixed to form a mixed combustion gas having a low oxygen concentration, thereby effectively reusing the boiler flue gas.

Referring to fig. 4, according to some embodiments of the present utility model, the main gas passage 500 is provided with a second through hole 520 communicating with the main combustion air passage 600 so that a portion of the main combustion air can be preliminarily premixed with the main gas, thereby providing more oxygen.

Further, the burner may be provided with an interlock control circuit, the interlock control circuit being connected to the control circuit of the fuel injection lance, while the burner is connected to an exhaust gas electric control valve for controlling the supply of smelting exhaust gas, and when the control circuit controls the gas electric control valve to close so as to cut off the supply of ignition gas, the interlock control circuit controls the exhaust gas electric control valve to close so as to cut off the supply of smelting exhaust gas.

It will be appreciated by those skilled in the art that when the burner provided by the present utility model is applied to a large boiler, it is necessary to use a plurality of burners for ignition of smelting off-gas in order to ensure that the boiler is full of heat in a short period of time. The method can use the mode that the plurality of burners are distributed in a stepped mode, and when the boiler works, compared with the mode that the plurality of burners are distributed in a straight line or matrix mode, the smelting tail gas is ignited simultaneously by the plurality of burners distributed in the stepped mode, so that the boiler can be filled with heat more rapidly with fewer burners, and the production efficiency is improved through a reasonable burner distribution mode.

In other embodiments, in the multiple combustors distributed in a stepped manner, the multiple fuel spray guns can be used for igniting the smelting tail gas in steps, namely after the fuel spray gun of the upper stage ignites the smelting tail gas sprayed by the corresponding combustor, the fuel spray gun of the lower stage ignites the smelting tail gas sprayed by the corresponding combustor, meanwhile, the smelting tail gas ignited by the upper stage can be used as a ignition source to ignite part of the smelting tail gas of the lower stage, so that the combustion speed of the smelting tail gas of the lower stage is accelerated, and the ignition fuel is saved.

In other embodiments, in the plurality of combustors distributed in a stepped manner, only one fuel spray gun can be provided as an ignition source, for example, only one fuel spray gun serving as an ignition source is provided at the topmost end of a step, when the plurality of combustors simultaneously spray smelting tail gas, the ignition source firstly ignites the smelting tail gas sprayed by the combustor positioned at the topmost end of the step, then the ignited smelting tail gas is utilized as an ignition source to ignite the smelting tail gas of the next stage, and so on, so that all the smelting tail gas is gradually ignited, and a large amount of ignition fuel is saved.

Furthermore, in the multiple burners of the boiler of the above embodiment, an interlock protection circuit may be provided, and the multiple burners are connected with an exhaust gas electric control valve for controlling the supply of the smelting exhaust gas, and simultaneously detect the states of all the fuel spray guns through setting up sensors, and when detecting that the flames of all the fuel spray guns are extinguished, the sensors transmit signals to the interlock protection circuit, and the interlock protection circuit immediately controls all the exhaust gas electric control valves to be closed so as to cut off the supply of all the smelting exhaust gas.

In the embodiment of the present utility model, the connecting member may be a clip or a plate with other shapes, and the connecting manner may be a fastening manner, a screw fixing manner, or a welding manner, which will not be described herein.

The embodiments of the present utility model have been described in detail with reference to the accompanying drawings, but the present utility model is not limited to the above embodiments, and various changes can be made within the knowledge of one of ordinary skill in the art without departing from the spirit of the present utility model.

Claims (10)

1. A fuel lance, comprising:

the spray gun comprises a spray gun body, wherein the spray gun body is provided with a first chamber, an ignition gas pipe and an igniter are arranged in the first chamber, the rear end of the spray gun body is provided with a natural gas pipe communicated with the ignition gas pipe, and an ignition electrode of the igniter is arranged at a nozzle of the ignition gas pipe;

the outer wall of spray gun body is provided with the intercommunication first air passage of first cavity, first air passage is used for connecting the fan, the spout end of spray gun body is provided with a plurality of first gas passage, and is a plurality of first gas passage centers on ignition gas pipe sets up, first gas passage intercommunication first cavity and orientation the spout direction slope of ignition gas pipe, the middle part of first gas passage is provided with first shrink ring, the flow area of first shrink ring is less than the flow area of first gas passage entry.

2. The fuel lance of claim 1 wherein the flow area of the first gas passage outlet is greater than the flow area of the first constriction ring.

3. The fuel spray gun according to claim 2, wherein the nozzle end of the ignition gas pipe is provided with a plurality of first spray holes and second spray holes, the first spray holes extend along the axial direction of the ignition gas pipe, the direction of the second spray holes is perpendicular to the direction of the first spray holes, and the outer peripheral wall of the ignition gas pipe is uniformly provided with a plurality of first through holes communicated with the first chamber.

4. A fuel lance according to claim 3, in which the lance body is provided with a flame detector integral with the ignition gas tube in the form of a concentric sleeve, the flame detector being located in the centre of the ignition gas tube.

5. A burner comprising a fuel lance as claimed in any one of claims 1 to 4.

6. The burner of claim 5, further comprising:

the shell is connected with a rear cover and a fire cover, the rear cover and the fire cover are arranged oppositely, a second cavity is formed by surrounding the shell, the fire cover is provided with a central nozzle, a first nozzle and a second nozzle, the spray gun body is positioned in the center of the second cavity, and the nozzle of the ignition gas pipe is communicated with the central nozzle;

the main gas channel is arranged in the second chamber, the rear cover is provided with a diversion chamber communicated with the main gas channel, the rear cover is connected with a main gas pipe communicated with the diversion chamber, and the main gas channel is communicated with the first nozzle;

the main combustion-supporting air channel is arranged in the second cavity, the shell is provided with a second air channel communicated with the main combustion-supporting air channel, the second air channel is used for being connected with a fan, and the main combustion-supporting air channel is communicated with the second nozzle.

7. The burner of claim 6, wherein the lance body is mounted to the rear cover, the lance body extends through the second chamber, the intake end of the lance body is located outside the housing, the first air passage is disposed at the intake end of the lance body, a flame detector is disposed within the lance body, and a viewing port of the flame detector extends beyond the intake end of the lance body.

8. The burner of claim 7, wherein the lance body, the main gas passage and the main combustion air passage are disposed in the second chamber from the center to the outside in sequence, the main gas passage and the main combustion air passage each being disposed around the lance body.

9. The burner of claim 8, wherein the primary gas passage includes a second gas passage, an outlet of the second gas passage communicates with the first nozzle, a middle portion of the second gas passage is provided with a second constriction ring, a flow area of the second constriction ring is smaller than a flow area of an inlet of the second gas passage, the primary combustion air passage includes a third gas passage, an outlet of the third gas passage communicates with the second nozzle, a middle portion of the third gas passage is provided with a third constriction ring, and a flow area of the third constriction ring is smaller than a flow area of an inlet of the third gas passage.

10. The burner of claim 9 wherein the flow area of the second gas passage outlet is greater than the flow area of the second constriction ring and the flow area of the third gas passage outlet is greater than the flow area of the third constriction ring.