CN216744351U - Burner and industrial furnace - Google Patents

Abstract

The utility model provides a burner and an industrial furnace, the burner is used for a furnace or a boiler, the burner receives input gas and outputs the gas to the furnace or the boiler, a first gas channel and a second gas channel for conveying the gas are configured in the burner, an outlet of the first gas channel and an outlet of the second gas channel are arranged on the same side of the burner in a spaced mode, wherein the cross-sectional area of the outlet of the first gas channel is larger than that of the outlet of the second gas channel, and the cross-sectional shape of the outlet of the first gas channel is configured to be triangle-like.

Description

Burner and industrial furnace

Technical Field

The utility model relates to the technical field of combustion, in particular to a combustor for a furnace or a boiler and an industrial furnace with the combustor.

Background

In industrial kilns or boilers, fuel and oxidant are typically passed through burners into the interior space of the kiln or boiler and ignited by the burners. However, many times, combustion in a kiln or boiler may result in the production of a large amount of nitrogen oxides (NOx) due to high combustion temperatures, uneven mixing of fuel and air, etc., thereby possibly causing environmental pollution.

In industrial combustion, there are generally methods for reducing the amount of NOx formed during combustion as follows:

1. premixed combustion, the combustion air and fuel are already mixed before entering the combustion chamber. This often requires a high amount of excess air to achieve low NOx combustion;

2. staged combustion, in which fuel or air is gradually mixed in a combustion chamber in a layered manner and then combusted, wherein the early combustion is carried out under the condition of excessive air quantity or excessive fuel quantity, and the later combustion is accompanied with the combustion of flame mixed with flue gas in a furnace, so that the low NOx combustion of low excess air is realized;

3. and (3) circulating combustion of external flue gas, namely returning the flue gas generated by partial combustion from the smoke exhaust part to the combustor to mix with air or fuel gas, and then combusting.

In staged combustion, it is important how the flue gas is entrained as much as possible by the jet of gas output by the burner and a suitable flame length is produced, so that a uniform and temperature-suitable combustion is achieved in the furnace. The number and distribution of the channels of the burner output gas, the cross-sectional shape of the channel outlets, the center-to-center spacing of the channel outlets, and the included angle of the output gas jets, all affect the entrainment of the flue gas and the change in the length of the flame. In existing burners, the outlet of the passage for the burner output gas usually takes a circular cross-sectional shape, and the burner is usually designed to be large in size.

SUMMERY OF THE UTILITY MODEL

The technical problem to be solved by one aspect of the present invention is how to reduce the content of nitrogen oxides generated by combustion in a kiln or boiler.

In addition, other aspects of the present invention are directed to solving or alleviating other technical problems in the prior art.

The utility model provides a burner and an industrial furnace, in particular, according to one aspect of the utility model, the utility model provides:

a burner for a kiln or boiler, which receives an input of gas and outputs the gas into the kiln or boiler, wherein a first gas channel and a second gas channel for conveying the gas are formed in the burner, and an outlet of the first gas channel and an outlet of the second gas channel are arranged on the same side of the burner at a distance from each other, wherein the cross-sectional area of the outlet of the first gas channel is larger than the cross-sectional area of the outlet of the second gas channel, and the cross-sectional shape of the outlet of the first gas channel is formed in a triangular-like shape.

Alternatively, according to one embodiment of the utility model, an igniter is configured on the burner, the ignition head of which is arranged on the side of the burner which outputs the gas and outside the first gas channel and the second gas channel.

Optionally, according to an embodiment of the utility model, a third gas channel is also formed in the burner, the outlet of the third gas channel being arranged in the first gas channel or in the second gas channel, an igniter being formed on the third gas channel, the ignition head of the igniter being arranged at the outlet of the third gas channel.

Optionally, in accordance with an embodiment of the present invention, the first gas channel is configured to input one of an oxidant and a fuel, and the second gas channel is configured to input the other of the oxidant and the fuel.

Optionally, according to an embodiment of the utility model, the first and second gas channels are configured to input the same type of gas, the first and second gas channels are configured to input one of an oxidant and a fuel, and the third gas channel is configured to input the other of the oxidant and the fuel.

Alternatively, according to an embodiment of the utility model, the oxidant is air or pure oxygen or oxygen-enriched gas.

Optionally, according to an embodiment of the utility model, the sides of the cross-section of the triangle-like shape of the outlet of the first gas channel are configured as straight lines or arcs or curves.

Alternatively, according to an embodiment of the present invention, the cross-section of the outlet of the second gas channel is configured in a triangular shape or a fan shape or a rectangular shape.

Alternatively, according to an embodiment of the present invention, the cross-sectional shape of the outlet of the first gas passage is configured as an equilateral triangle, and/or the cross-sectional shape of the outlet of the second gas passage is configured as an equilateral triangle.

Alternatively, according to an embodiment of the present invention, the cross section of the outlet of the first gas passage is configured in a triangular shape, the number of the second gas passages is one and the cross section of the outlet thereof is configured in a triangular shape, and one side of the cross section of the outlet of the first gas passage and one side of the triangular cross section of the outlet of the second gas passage are parallel to and face each other.

Alternatively, according to an embodiment of the utility model, the cross-section of the outlet of the second gas channel is configured as an equilateral triangle and the cross-section of the outlet of the first gas channel is configured as an equilateral triangle.

Alternatively, according to an embodiment of the utility model, the cross-sectional shape of the side of the burner outputting gas is square, the cross-section of the outlet of the first gas channel is arranged in the centre of the square, and the cross-section of the outlet of the second gas channel is in the corner area of the square in the square cross-section of the burner.

Optionally, according to an embodiment of the utility model, the geometric center of the cross-section of the outlet of the first gas channel coincides with the center of the square.

Optionally, in accordance with an embodiment of the present invention, the first gas channel and the second gas channel are configured such that an angle between a jet of gas flowing out of the first gas channel and a jet of gas flowing out of the second gas channel is 45 ° or less.

Optionally, in accordance with an embodiment of the present invention, the first gas channel and the second gas channel are configured such that an angle between a jet of gas flowing out of the first gas channel and a jet of gas flowing out of the second gas channel is 15 ° or less.

Alternatively, according to an embodiment of the present invention, the number of the second gas channels is 2 to 3.

Alternatively, according to an embodiment of the present invention, a center-to-center distance ratio n of the first gas passage and the second gas passage satisfies the following formula:

n=s/(R1+R2);

s is the distance between the geometric centers of the cross-sections of the outlets of the first and second gas channels; r1 is the radius of an equivalent circle having an area equal to the cross section of the outlet of the first gas passage; r2 is the radius of an equivalent circle having an area equal to the cross section of the outlet of the second gas channel;

and n has a value between 2 and 5.

According to another aspect of the utility model, the utility model provides an industrial furnace, wherein the industrial furnace has a burner as described above.

The beneficial effects of the utility model include: the triangular cross section is adopted as the outlet of the first gas channel of the burner, the capacity of smoking smoke gas output from the burner is improved under the condition of keeping the size of the burner to reduce the length of flame and ensure the proper flame direction, thereby reducing the amount of nitrogen oxide generated by combustion in a furnace or a boiler to a great extent, improving the uniformity of flame temperature and playing a role in protecting the environment.

Drawings

The above and other features of the present invention will become apparent with reference to the accompanying drawings, in which,

fig. 1 shows a longitudinal sectional view of a proposed burner according to a first embodiment of the utility model;

fig. 2 shows a side view of the proposed burner from the side of the output gas according to a first embodiment of the utility model;

fig. 3 shows a longitudinal sectional view of a proposed burner according to a second embodiment of the utility model;

fig. 4 shows a side view of the proposed burner from the side of the output gas according to a second embodiment of the utility model;

fig. 5 shows a longitudinal sectional view of the proposed burner according to a third embodiment of the utility model;

fig. 6 shows a side view of the proposed burner from the side of the output gas according to a third embodiment of the utility model;

fig. 7 shows a longitudinal sectional view of the proposed burner according to a fourth embodiment of the utility model;

fig. 8 shows a side view of the proposed burner from the side of the output gas according to a fourth embodiment of the utility model;

fig. 9 shows a longitudinal sectional view of the proposed burner according to a fifth embodiment of the utility model;

fig. 10 shows a side view of the proposed burner from the side of the output gas according to a fifth embodiment of the utility model.

Detailed Description

It is easily understood that according to the technical solution of the present invention, a person skilled in the art can propose various alternative structural modes and implementation modes without changing the essential spirit of the present invention. Therefore, the following detailed description and the accompanying drawings are merely illustrative of the technical aspects of the present invention, and should not be construed as all of the present invention or as limitations or limitations on the technical aspects of the present invention.

The terms of orientation of up, down, left, right, front, back, top, bottom, and the like referred to or may be referred to in this specification are defined relative to the configuration shown in the drawings, and are relative terms, and thus may be changed correspondingly according to the position and the use state of the device. Therefore, these and other directional terms should not be construed as limiting terms. Furthermore, the terms "first," "second," "third," and the like are used for descriptive and descriptive purposes only and not for purposes of indication or implication as to the relative importance of the respective components.

Referring to fig. 1 and 2, there are shown a longitudinal sectional view of a proposed burner 100 according to a first embodiment of the present invention and a side view from the side of the burner 100 from which gas is output. The burner 100 is used for a kiln or a boiler, and includes a first gas passage 101, a second gas passage 102, a burner body 103, and an igniter 104. For convenience of expression, a direction in which the gas flows along the first or second gas passage is defined as a longitudinal direction of the burner 100, and a direction perpendicular to the longitudinal direction is defined as a lateral direction of the burner 100. The burner 100 receives input gas and outputs the gas to a kiln or boiler, and the input gas may be burned in the burner 100 or on the side of the burner 100 from which the gas is output, depending on the type of igniter 104 and the location in the burner 100 where the igniter 104 is disposed. The combustion of the gas in the burner 100 produces flames, and the different lengths and shapes of flames may limit the application of the burner 100, for example if the length of the flame produced by the burner 100 is too long, it may not be suitable for a smaller size boiler or kiln, thus achieving as small a flame length in the burner 100 as possible. The gas output side of the burner 100 is generally square or circular in cross-section, although other shapes are possible. In the embodiment of the utility model only a square-shaped cross-section is shown, but the structural and technical features of the burner of the utility model can also be applied in burners with cross-sections of other shapes.

In the first embodiment, the number of the first gas passages 101 and the second gas passages 102 is one. The outlets of the first gas channel 101 and the second gas channel 102 are arranged on the same side of the burner 100 at a distance from each other, and the inlets of the first gas channel 101 and the second gas channel 102 are arranged on the other side of the burner 100 opposite thereto, although the inlets may also be arranged on the other side of the burner 100, either together or separately, differently from the outlets. The cross-sectional area of the outlet of the first gas channel 101 is larger than that of the outlet of the second gas channel 102. The first gas channel 101 is configured to input one of an oxidant and a fuel, and the second gas channel 102 is configured to input the other of the two, for example, the first gas channel 101 is configured to input air, and the second gas channel 102 is configured to input fuel, and the types of gases input into the first gas channel 101 and the second gas channel 102 may be selected depending on the ratio between the gases to be input. In the present invention, the oxidant mentioned may be air or pure oxygen or oxygen-enriched gas, where oxygen-enriched gas refers to oxygen-containing gas for combustion supporting having an oxygen concentration greater than that in air. The cross-sectional shape of the outlet of the first gas channel 101 is configured into a triangle-like shape, which is defined herein to include a triangular shape and a shape that assumes a triangle-like shape as a whole, and the sides of the cross-section that form the triangle-like shape may be straight lines, inwardly or outwardly protruding arcs, or irregular curves. The cross-sectional shape of the outlet of the second gas passage 102 is also configured into the triangular-like shape, and further, can be configured into a fan shape or a rectangular shape. In the first embodiment, as shown in fig. 2, the cross-sectional shapes of the outlets of the first gas passage 101 and the second gas passage 102 are both configured as equilateral triangles, but may be configured as other types of triangles, such as isosceles triangles and right-angled triangles. Through testing and experiments on different cross-sectional shapes, it can be known that when the cross-sectional shape of the outlet of the first gas channel 101 and/or the second gas channel 102 is designed to be triangular, especially when the cross-sectional shape of the outlet of the first gas channel 101 is designed to be triangular, the gas jet output therefrom can efficiently and more uniformly entrain flue gas in a furnace or a boiler, and can enable the flame length to be smaller, so that the burner 100 can be suitable for boilers or furnaces with different sizes. The equilateral triangular design at the cross section of the outlet promotes better entrainment of the flue gases and facilitates processing. Further, in the first embodiment, one side of the triangle of the cross section of the outlet of the first gas passage 101 and one side of the triangle of the cross section of the outlet of the second gas passage 102 are parallel to each other and face each other. The expression "facing each other" means that there are no other sides of the two triangles between the straight lines of the sides of the two triangles parallel to each other, that is to say there is only a part of the body of the burner 100 between them and no gas channel or part thereof, such an arrangement being able to increase the efficiency of the entrainment of the fumes and also being advantageous to adjust the angle between the jets of gas output from the first gas channel 101 and the second gas channel 102.

In the first embodiment, the igniter 104 is a spark plug igniter, and the ignition head 105 of the igniter 104 is arranged on the side of the burner 100 that outputs gas and outside the first gas passage 101 and the second gas passage 102. In this way, the gases do not burn in the first gas channel 101 and the second gas channel 102, but flow out of the first gas channel 101 and the second gas channel 102, are mixed and burned after being ignited by the igniter 100. In this combustion, the amount of NOx produced can be greatly reduced.

Referring to fig. 3 and 4, there are respectively shown a longitudinal sectional view of the proposed burner 200 according to the second embodiment of the present invention and a side view from the side of the burner 200 from which gas is output. In the second embodiment, the burner 200 includes a first gas passage 201, a second gas passage 202, and a third gas passage 203, a burner body 204, and an igniter 205, the number of the first gas passage 201, the second gas passage 202, and the third gas passage 203 being one, respectively. As in the first embodiment, the outlet of the first gas passage 201 and the outlet of the second gas passage 202 are arranged on the same side of the burner 200 at a distance from each other and the cross-sectional area of the outlet of the first gas passage 201 is larger than that of the outlet of the second gas passage 200. In contrast to the first exemplary embodiment, the burner 200 has a third gas channel 203 more gas channels than in the first exemplary embodiment, the gas outlet of the third gas channel 203 being arranged in the first gas channel 201. The inlets of the first gas channel 201 and the second gas channel 202 are connected to a common inlet 207 of the burner 200, so that the first gas channel 201 and the second gas channel 202 are configured to input the same type of gas. The first gas passage 201 and the second gas passage 202 are configured to input one of an oxidant and a fuel, and the third gas passage 203 is configured to input the other of the oxidant and the fuel. The igniter 205 is configured on the third gas channel 203, and an ignition head 206 of the igniter 205 is arranged at an outlet of the third gas channel 203. Of course, the igniter 205 of the second embodiment may be directly configured as the igniter 205 having the third gas channel 203, and the gas may be output to the ignition head 206 of the igniter 205 through the third gas channel 203, in which case the third gas channel 203 is a part of the igniter 205. Thus, the gas of the third gas channel 203 is introduced into the first gas channel 201 and mixed with the gas in the first gas channel 201, and ignited by the igniter 205 and then burned to form a mixed gas, and finally outputted from the first gas channel 201. The output of the burner 200 in the second embodiment is a mixture of the fuel and the oxidant after combustion and one of the fuel and the oxidant.

In the second embodiment, as in the first embodiment, one side of the triangle of the cross section of the outlet of the first gas passage 201 and one side of the triangle of the cross section of the outlet of the second gas passage 202 are parallel to and face each other, and the cross section of the outlet of the first gas passage 201 is configured as an equilateral triangle. In contrast to the first embodiment, in the second embodiment, the geometric center of the cross-section of the outlet of the first gas channel 201 (here embodied as the center of gravity of a triangle) coincides with the geometric center of the square cross-section of the burner 200. The cross section of the outlet of the second gas channel 202 is configured as an isosceles right triangle and it is arranged at the corner area of said square cross section, the two legs of the isosceles right triangle facing the two legs of the square respectively and being parallel to the two legs of the square. The cross-section of the second gas channel outlet 202 can also be configured as a sector with a central angle of 90 °. Such an arrangement makes it possible to make the distance between the first gas channel 201 and the second gas channel 202 as large as possible in the square cross section, thereby improving the efficiency of the two gases output to entrain the flue gas, without increasing the volume of the burner 200, and making full use of the limited cross-sectional area of the burner 200.

Referring to fig. 5 and 6, there are respectively shown a longitudinal sectional view of a proposed burner 300 according to a third embodiment of the present invention and a side view from a side of the burner 300 from which gas is output. In the third embodiment, the burner 300 has the third gas channel 303 as in the second embodiment and the igniter 305 is also arranged as in the second embodiment. Unlike the second embodiment, the burner 300 has two second gas passages 302 in the third embodiment. Both the second gas channels 302 are configured as isosceles right triangles (which may also be configured as sectors with a central angle of 90 °) and are arranged respectively at two corner regions of the square cross-section of the burner 300, i.e. in the regions close to the four vertices of the square cross-section, the two legs of the isosceles right triangles facing respectively and being parallel to the two legs of the square. The cross section of the outlet of the first gas channel 301 is also configured as an equilateral triangle and its center coincides with the center of the square cross section of the burner 300. This allows the two second gas channels 302 to be located at the same distance from the first gas channel 301 and makes full use of the square cross-sectional area, so that the overall burner 300 is not too bulky.

Referring to fig. 7 and 8, there are respectively shown a longitudinal sectional view of a burner 400 proposed according to a fourth embodiment of the present invention and a side view seen from a side from which gas is output from the burner 400. In the fourth embodiment, the burner 400 has a third gas passage 403 as in the third embodiment and a first gas passage 401, an igniter 405 are also arranged in a burner body 404 as in the third embodiment. In the fourth embodiment, the burner 400 has three second gas channels 402 and is arranged at three corner regions of the square cross section of the burner 400, respectively, unlike the third embodiment, and likewise, the outlet shapes of the three second gas channels 402 are configured as isosceles right triangles, and two legs of the isosceles right triangles face and are parallel to two legs of the square cross section of the burner 400, respectively. This also achieves that the distances between the geometric centers of the cross-sections of the outlets of the three second gas channels 402 and the geometric centers of the cross-sections of the outlets of the first gas channels 401 are equal.

Referring to fig. 9 and 10, there are respectively shown a longitudinal sectional view of a proposed burner 500 according to a fifth embodiment of the present invention and a side view from a side of the burner 500 outputting gas. In the fifth embodiment, the burner 500 also has three second gas passages 502, and the first gas passage 501, two of the second gas passages 502, and the igniter 505 are arranged in the burner body 504 in the same manner as in the third embodiment. While the triangular cross-section of the outlet of the other second gas channel 502 is parallel to and faces each other with its one side and the triangular cross-section of the outlet of the first gas channel 501 and is arranged in the middle of the two gas channels 502 in the corner regions of the square cross-section of the burner 500.

It should be understood that in the second, third, fourth and fifth embodiments, the outlet of the third gas passage 203, 303, 403, 503 can also be arranged in the second gas passage 202, 302, 402, 502, when the gas is combusted in the second gas passage 202, 302, 402, 502 to form a mixed gas and discharged from the second gas passage 202, 302, 402, 502, the gas discharged from the first gas passage 201, 301, 401, 501 being one of a fuel or an oxidant.

Furthermore, it is advantageous in all the embodiments described above that the first gas channel 101, 201, 301, 401, 501 and the second gas channel 102, 202, 302, 402, 502 are configured such that the angle between the jet of gas flowing out of the first gas channel 101, 201, 301, 401, 501 and the jet of gas flowing out of the second gas channel 102, 202, 302, 402, 502 is less than or equal to 45 °, and preferably less than or equal to 15 °, which can be achieved by adjusting the direction of extension of the first gas channel 101, 201, 301, 401, 501 and the second gas channel 102, 202, 302, 402, 502 in the burner 100, 200, 300, 400, 500. The positive and negative included angle between the jets is defined herein, positive if the two jets exit the burner in a direction away from each other, and negative if the two jets exit the burner in a direction towards each other. In this case, 45 ° and 15 ° are described as defining the absolute value of the included angle. The included angle between the efflux can influence the efficiency that the gas efflux carries out the entrainment to the flue gas. With a large positive included angle between the jets, the two jets mix later, entraining the flue gas for a long duration, but possibly making the flame length larger. Under the condition that a large negative included angle (the absolute value of the negative included angle is large) exists between the jet flows, the flame length is small, the application of a combustor is facilitated, but the two jet flows are mixed early, the combustion occurs early, the duration of entrainment smoke is short, and the efficiency of entrainment smoke is possibly influenced. Therefore ± 15 ° is generally chosen as the optimum for the angle between the jets.

In addition, the center-to-center ratio defining the first gas channel 101, 201, 301, 401, 501 and the single second gas channel 102, 202, 302, 402, 502 is n = s/(R1+ R2), where s is the distance between the first gas channel 101, 201, 301, 401, 501 and the geometric center of the cross section of the outlet of the second gas channel 102, 202, 302, 402, 502, R1 is the radius of an equivalent circle having an area equal to the cross section of the outlet of the first gas channel 101, 201, 301, 401, 501, and R2 is the radius of an equivalent circle having an area equal to the cross section of the outlet of the single second gas channel 102, 202, 302, 402, 502. Then the center-to-center ratio n should satisfy 2 ≦ n ≦ 5 in all the embodiments described above. The center-to-center ratio is a parameter that can comprehensively consider the distance between the first gas channel 101, 201, 301, 401, 501 and the second gas channel 102, 202, 302, 402, 502 and the size of the outlet cross section of each of the first gas channel 101, 201, 301, 401, 501 and the second gas channel 102, 202, 302, 402, 502. The range of 2 ≦ n ≦ 5 gives the criterion how to determine the distance between the gas channels of different cross-sectional areas in order to be able to achieve a high efficiency of entrainment of the flue gas.

The gas jet speed of combustor output has the influence to the ability of combustor entrainment flue gas, and the gas jet's speed is high to be favorable to the flue gas entrainment, reduces NOx's content, thereby also can accelerate the mixture of air and gas simultaneously and influence the flue gas entrainment, makes the burning aggravate and influence the control to NOx. Therefore, in all the embodiments described above, the flow rate of the gas flowing out of the first gas passage 101, 201, 301, 401, 501 is generally controlled to be 30 to 150m/s, and the flow rate of the gas flowing out of the second gas passage 102, 202, 302, 402, 502 is controlled to be 80 to 250 m/s.

In the second, third, fourth and fifth embodiments, the degree of classification of the gas also affects the entrainment of the flue gas. The degree of classification of the gases is primarily the proportion by mass of the gases fed directly from outside the burner 200, 300, 400, 500 into the first gas duct 201, 301, 401, 501 to the total gases fed directly from outside the burner 200, 300, 400, 500 into the first gas duct 201, 301, 401, 501 and into the second gas duct 202, 302, 402, 502. When the mass ratio is lower, the flame burner is beneficial to absorbing smoke, slowing down the mixing of air and fuel gas and reducing the generation of NOx, but the flame form may be deteriorated, the length is increased, and the application of the burner is limited. At higher mass ratios, the flame length is lower, but the efficiency of entraining the flue gas is reduced. In the utility model, the mass ratio is controlled to be 15-60%, which is more beneficial to the consideration of entrainment efficiency and flame length.

According to another aspect of the utility model, an industrial furnace is also claimed, having a burner according to the utility model.

It should be understood that all of the above preferred embodiments are exemplary and not restrictive, and that various modifications and changes in the specific embodiments described above, which would occur to persons skilled in the art upon consideration of the above teachings, are intended to be within the scope of the utility model.

Claims (18)

1. A burner for a kiln or boiler, which burner receives an input of gas and outputs gas into the kiln or boiler, in which burner a first gas channel and a second gas channel for conveying gas are configured, the outlet of the first gas channel and the outlet of the second gas channel being arranged at a distance from each other on the same side of the burner, characterized in that the cross-sectional area of the outlet of the first gas channel is larger than the cross-sectional area of the outlet of the second gas channel, the cross-sectional shape of the outlet of the first gas channel being configured as a triangle-like shape.

2. The burner of claim 1, wherein an igniter is configured on the burner, an ignition head of the igniter being disposed on a side of the burner output gas and being disposed outside the first gas passage and the second gas passage.

3. The burner of claim 1, wherein a third gas channel is also formed in the burner, the outlet of the third gas channel being arranged in the first gas channel or the second gas channel, an igniter being formed on the third gas channel, the ignition head of the igniter being arranged at the outlet of the third gas channel.

4. The burner of claim 2, wherein the first gas passage is configured to input one of an oxidant and a fuel and the second gas passage is configured to input the other of the oxidant and the fuel.

5. The burner of claim 3, wherein the first and second gas passages are configured to input the same type of gas, the first and second gas passages are configured to input one of an oxidant and a fuel, and the third gas passage is configured to input the other of the oxidant and the fuel.

6. A burner according to claim 4 or 5, wherein the oxidant is air or pure oxygen or oxygen-enriched gas.

7. The burner according to any one of claims 1 to 5, wherein the sides of the cross-section of the triangle-like shape of the outlet of the first gas channel are configured as straight lines or circular arcs or curves.

8. The burner according to any one of claims 1 to 5, wherein the cross-section of the outlet of the second gas channel is configured in a triangular shape or a fan shape or a rectangular shape.

9. The burner according to any one of claims 1 to 5, wherein the cross-sectional shape of the outlet of the first gas channel is configured as an equilateral triangle, and/or the cross-sectional shape of the outlet of the second gas channel is configured as an equilateral triangle.

10. The burner according to any one of claims 1 to 5, wherein the cross section of the outlet of the first gas passage is configured in a triangular shape, the number of the second gas passages is one and the cross section of the outlet thereof is configured in a triangular shape, and one side of the cross section of the outlet of the first gas passage and one side of the triangular cross section of the outlet of the second gas passage are parallel to and face each other.

11. The burner of claim 10, wherein the cross-section of the outlet of the second gas passage is configured as an equilateral triangle and the cross-section of the outlet of the first gas passage is configured as an equilateral triangle.

12. A burner according to claim 3, wherein the cross-sectional shape of the side of the burner outputting gas is square, the cross-section of the outlet of the first gas channel being arranged in the centre of the square, and the cross-section of the outlet of the second gas channel being in the corner area of the square in the square cross-section of the burner.

13. The burner of claim 12, wherein a geometric center of a cross-section of an outlet of the first gas channel coincides with a center of the square.

14. The burner of any one of claims 1 to 5, wherein the first gas channel and the second gas channel are configured such that an angle between a jet of gas flowing out of the first gas channel and a jet of gas flowing out of the second gas channel is 45 ° or less.

15. The burner of claim 14, wherein the first gas channel and the second gas channel are configured such that an angle between a jet of gas flowing from the first gas channel and a jet of gas flowing from the second gas channel is 15 ° or less.

16. A burner according to claim 3, wherein the number of the second gas channels is 2 to 3.

17. The burner according to any one of claims 1 to 5, wherein a center-to-center distance ratio n of the first gas passage and the second gas passage satisfies the following formula:

n=s/(R1+R2);

s is the distance between the geometric centers of the cross-sections of the outlets of the first and second gas channels; r1 is the radius of an equivalent circle having an area equal to the cross section of the outlet of the first gas channel; r2 is the radius of an equivalent circle having an area equal to the cross section of the outlet of the second gas channel;

and n has a value between 2 and 5.

18. An industrial furnace characterized by having a burner according to any one of claims 1 to 17.

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