CN212132430U - gas burner - Google Patents

Abstract

The utility model provides a gas burner, include: the combustion chamber is of a cylindrical structure with openings at two ends and is provided with an inner cavity; the circulating sleeve is of a stepped structure and is positioned in the inner cavity, the large-diameter section of the circulating sleeve is abutted against the inner wall of the first end of the combustion chamber, a plurality of premixing cavities for connecting input air are arranged on the large-diameter section, the first end of the small-diameter section is connected with the large-diameter section, the second end of the small-diameter section is in an open shape and is opposite to the second end of the combustion chamber, an annular space is formed between the small-diameter section and the inner wall of the combustion chamber, the premixing cavities are communicated with the annular space, and a smoke port group is arranged on the periphery of the small-diameter section; a plurality of first-stage gas spray guns are correspondingly arranged in each premixing cavity in a penetrating manner; and the secondary gas spray gun axially penetrates through the circulating sleeve, and the outlet end of the secondary gas spray gun is arranged outside the circulating sleeve and faces the second end of the combustion chamber. The embodiment keeps the original characteristics of high-speed combustion of jet-enhanced convection heating, and has the low-nitrogen combustion effect.

Description

gas burner

technical field

The utility model relates to the field of industrial heating and heat treatment, in particular to a gas burner.

Background technique

The high-speed burner has the characteristics of compact structure, high convective heat transfer coefficient and good degree of automation, and is widely used in various heat treatment furnaces and heating furnaces. With the current increasingly serious air pollution problems forcing the implementation of more stringent ultra-low pollutant emission standards all over the country, the realization of clean and low-nitrogen combustion of industrial heating and heat treatment equipment is of great significance for green and sustainable development.

The traditional high-speed burner focuses on the full mixing of fuel and air in the combustion chamber to obtain high-intensity combustion in a compact combustion volume, so as to achieve high-speed jet air velocity and ensure the convective heat transfer coefficient in the furnace to adapt to many processes. need. However, it is difficult for traditional high-speed burners to meet the current increasingly stringent ultra-low emission requirements for emission standards.

In recent years, there have also been many high-speed burners that use various staged combustion technologies to achieve low-polluting emissions, but such so-called high-speed burners essentially make part of the fuel enter the interior of the furnace and then burn, reducing the combustion intensity in the combustion chamber. Although it can achieve the effect of low-nitrogen combustion, it sacrifices the jetting speed of the airflow for high-speed combustion, which affects the convective heat transfer effect, which is not conducive to uniform heating and energy saving.

Utility model content

The utility model provides a gas burner, so as to achieve the purpose of reducing the generation of pollutants on the premise of ensuring the injection speed.

The technical scheme adopted by the utility model to solve the technical problem is as follows: a gas burner, comprising: a combustion chamber, in the form of a cylindrical structure with two ends open, the combustion chamber has an inner cavity; In the inner cavity, the large-diameter section of the circulating sleeve is in contact with the inner wall of the first end of the combustion chamber, the large-diameter section is provided with a plurality of premixing cavities for connecting the input air, and the first end of the small-diameter section is connected to the large-diameter section. The second end of the small diameter section is open and opposite to the second end of the combustion chamber, there is an annular space between the small diameter section and the inner wall of the combustion chamber, the premixing cavity is communicated with the annular space, and the outer circumference of the small diameter section is provided with an annular space. A group of flue gas ports; a plurality of primary gas lances, each premixing chamber is provided with a primary gas lance; The outlet end is placed outside the annular flow sleeve and faces the second end of the combustion chamber.

Further, the plurality of premixing cavities are evenly spaced along the circumference of the large diameter section.

Further, there are multiple smoke port groups, and the positions of the multiple smoke port groups are in one-to-one correspondence with the positions of the multiple premixing chambers.

Further, each flue gas port group includes a main flue gas flow hole and a secondary flue gas flow hole. The diameter of the hole is larger than that of the auxiliary flue gas guide hole.

Further, the main flue gas flow hole is located at the first end of the small diameter section, there are multiple secondary flue gas flow holes, and the plurality of auxiliary flue gas flow holes are evenly spaced between the main flue gas flow hole and the second end of the small diameter section. between.

Further, the diameter of the opening of the first section of the combustion chamber is larger than the diameter of the opening of the second end of the combustion chamber, and an arc guide structure is provided at the connection between the opening of the second end of the combustion chamber and the inner cavity wall.

Further, the flow velocity of the nozzle of the primary gas lance is 40m/s～200m/s, and the primary gas ratio at the primary gas lance is 50～90%.

Further, the flow velocity of the nozzle of the secondary gas lance is 60m/s～150m/s, and the secondary gas ratio at the secondary gas lance is 10～50%.

Further, the gas burner further includes an air pipeline connected to the plurality of premixing chambers.

Further, the gas burner also includes a gas pipeline, which is connected to both the secondary gas lance and the multiple primary gas lances.

The beneficial effect of the utility model is that high-speed flue gas is formed by combustion at the primary gas lance, and after entering the annular space of the combustion chamber, under the guiding action of the circulation sleeve, a circulation effect is formed around the circulation sleeve, thereby reducing the peak value of the primary combustion temperature And suppress nitrogen oxides, and under the reduction effect of the gas injected by the secondary gas lance, it is completely burned and ejected from the second end of the combustion chamber, forming a high-speed jet of ultra-low emission.

Description of drawings

The accompanying drawings forming a part of the present application are used to provide further understanding of the present invention, and the schematic embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

1 is a structural diagram of an embodiment of the present utility model;

Fig. 2 is the layout drawing of the first-level gas spray gun of the present utility model;

FIG. 3 is a structural diagram of the circulating flow sleeve of the present invention.

Reference symbols in the figure: 1. Air pipeline; 2. Gas pipeline; 3. Primary gas lance; 4. Premixing chamber; 5. Secondary gas lance; 6. Combustion chamber; 7. Flue gas outlet; 8 , Circulation sleeve; 9. Main flow hole for flue gas; 10. Secondary flow hole for flue gas.

Detailed ways

It should be noted that the embodiments in the present application and the features of the embodiments may be combined with each other in the case of no conflict. The present utility model will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

As shown in FIGS. 1 to 3 , an embodiment of the present invention provides a gas burner, including a combustion chamber 6 , a circulating sleeve 8 , a plurality of primary gas lances 3 and secondary gas lances 5 . The combustion chamber 6 has a cylindrical structure with two ends open, and the combustion chamber 6 has an inner cavity. The circulation sleeve 8 has a stepped structure and is located in the inner cavity. The large-diameter section of the circulation sleeve 8 is in contact with the inner wall of the first end of the combustion chamber 6. The large-diameter section is provided with a plurality of preheaters for connecting the input air. In the mixing chamber 4, the first end of the small diameter section is connected with the large diameter section, the second end of the small diameter section is open and is opposite to the second end of the combustion chamber 6, and there is an annular space between the small diameter section and the inner wall of the combustion chamber 6, The premixing chamber 4 is communicated with the annular space, and the outer periphery of the small diameter section is provided with a group of flue gas ports. A first-stage gas lance 3 is correspondingly penetrated in each premixing chamber 4 . The secondary gas lance 5 is axially penetrated in the annular flow sleeve 8 , and the outlet end of the secondary gas lance 5 is placed outside the annular flow sleeve 8 and faces the second end of the combustion chamber 6 .

The first-stage gas lance 3 burns to form high-speed flue gas. After entering the annular space of the combustion chamber 6, under the guidance of the annular flow sleeve 8, a circulation effect is formed around the annular flow sleeve 8, thereby reducing the primary combustion temperature peak and inhibiting nitrogen oxidation. Under the reduction effect of the gas injected from the secondary gas lance 5, it is completely burned and ejected from the second end of the combustion chamber 6 to form a high-speed jet of ultra-low emission (nitrogen oxides below 150mg/m3).

The primary combustion at 3 of the primary gas lance adopts pre-mixing of gas and excess air. Since the primary gas is in a pre-mixed lean combustion state, it can ensure stable combustion of the flame and dilution of excess air at the same time. The peak temperature of the combustion flame is low, avoiding the need for Substantial generation of high temperature thermal nitrogen oxides in primary combustion.

The number of the primary gas lances 3 can be increased as required, and distributed in an annular array along the circumferential direction. The outlets of the primary gas lances 3 are all placed in the annular space, that is, the combustion area is formed by the inner surface of the combustion chamber 6 and the outer side of the annular flow sleeve 8 In the annular space, the positions of the plurality of premixing chambers 4 correspond to the positions of the primary gas lances 3 . After the high-temperature flue gas flow generated by the primary combustion flows out of the annular space, a part of the flue gas flows back from the inside of the annular flow sleeve 8 due to the effect of the ejection negative pressure, and flows back into the annular space at the position of the flue gas port group, thereby further diluting the combustion area. The oxygen concentration and gas concentration can reduce the intensity of the combustion reaction and further reduce the production of nitrogen oxides.

Another part of the flue gas is sprayed out at a high speed from the opening of the second end of the combustion chamber 6 (the flue gas outlet 7) and enters the furnace space, while the part of the gas sprayed by the secondary gas spray gun 5 can continue before the high temperature flue gas is sprayed out. During combustion, the oxygen concentration in the high _- temperature flue gas is greatly reduced, so the combustion reaction is relatively mild, and the production of a large amount of pollutants can also be avoided. The oxides play a reducing role, further reducing the pollutants produced in the combustion chamber.

It should be noted that the shape of the nozzle of the primary gas lance 3 may be a circular or non-axisymmetric special-shaped nozzle. The shape of the nozzle of the secondary gas lance 5 can be a circular or non-axisymmetric special-shaped nozzle, and the number of openings of the nozzle of the secondary gas lance 5 can be one or more combinations.

Specifically, there are multiple smoke port groups, and the multiple smoke port groups correspond to the positions of the multiple premixing chambers 4 one-to-one. Corresponding the flue gas port group with the premixing chamber 4 can make the flue gas flow back into the annular space, thereby further diluting the oxygen concentration and gas concentration in the combustion area, reducing the intensity of the combustion reaction, and further reducing the production of nitrogen oxides .

As shown in FIG. 1 and FIG. 3 , each smoke port group in the embodiment of the present invention includes a main flue gas flow hole 9 and a secondary flue gas flow guide hole 10 , and the main flue gas flow hole 9 and the secondary flue gas flow guide hole 10 . The holes 10 are arranged at intervals along the axial direction of the circulating sleeve 8 , and the diameter of the main flue gas flow holes 9 is larger than that of the secondary flue gas flow holes 10 . The purpose of arranging the main flue gas flow hole 9 and the secondary flue gas flow hole 10 is to increase the smoothness of the backflow of the flue gas, so as to prevent the flue gas from being sprayed out of the outlet due to the slow backflow of the flue gas.

Preferably, the main flue gas flow hole 9 is located at the first end of the small diameter section, there are multiple secondary flue gas flow holes 10, and the plurality of auxiliary flue gas flow holes 10 are evenly spaced between the main flue gas flow hole 9 and the small diameter section between the second ends. The main purpose of arranging the flue gas main flow hole 9 at the first end of the small diameter section is to make most of the flue gas start to dilute the oxygen concentration and gas concentration in the combustion area at the initial position of the annular space, and reduce the intensity of combustion reaction. The shapes of the main flue gas guide holes 9 and the secondary flue gas guide holes 10 may be circular, rectangular or other shapes.

As shown in FIG. 1 , the diameter of the opening of the first section of the combustion chamber 6 is larger than the diameter of the opening of the second end of the combustion chamber 6 , and an arc guide structure is provided at the connection between the opening of the second end of the combustion chamber 6 and the inner cavity wall. The arc guide structure is arranged corresponding to the position of the annular space, which can guide the flue gas ejected at a high speed in the annular space, so as to facilitate the return of the flue gas.

The flow velocity of the nozzle of the primary gas lance 3 is 40m/s～200m/s, and the primary gas ratio at the primary gas lance 3 is 50～90%. The flow velocity of the nozzle of the secondary gas lance 5 is 60m/s～150m/s, and the secondary gas ratio at the secondary gas lance 5 is 10～50%.

The gas burner further includes an air pipeline 1, which is connected to a plurality of premixing chambers 4. The gas burner further includes a gas pipeline 2 , which is connected to the secondary gas lance 5 and the plurality of primary gas lances 3 .

In the embodiment of the present invention, the air pipeline 1 and the gas pipeline 2 are provided to respectively provide air and gas to the combustion chamber, and the air and gas volume can be controlled independently, which is convenient to adjust the gas ratio.

From the above description, it can be seen that the above-mentioned embodiment of the present utility model achieves the following technical effects: the present utility model not only retains the characteristics of the original injection-enhanced convection heating of high-speed combustion, but also has the effect of low-nitrogen combustion, It realizes high-intensity and low-polluting combustion in a compact combustion space, and meets the low-polluting emission requirements of various heat treatment furnaces and heating furnaces that rely on convection heat transfer.

The above descriptions are only specific examples of the present invention, and cannot limit the scope of implementation of the present invention. Therefore, the replacement of the equivalent components thereof, or the equivalent changes and modifications made according to the scope of the patent protection of the present invention, shall still belong to the scope of the present invention. Scope covered by this patent. In addition, the technical features and technical features, the technical features and the technical solutions, and the technical solutions and the technical solutions can be freely combined and used in the present invention.

Claims (10)

1. A gas burner, comprising:

the combustion chamber (6) is of a cylindrical structure with openings at two ends, and the combustion chamber (6) is provided with an inner cavity;

the circulating sleeve (8) is of a stepped structure and is positioned in the inner cavity, a large-diameter section of the circulating sleeve (8) is abutted to the inner wall of the first end of the combustion chamber (6), a plurality of premixing cavities (4) used for connecting input air are arranged on the large-diameter section, the first end of a small-diameter section of the circulating sleeve (8) is connected with the large-diameter section, the second end of the small-diameter section is open and opposite to the second end of the combustion chamber (6), an annular space is formed between the small-diameter section and the inner wall of the combustion chamber (6), the premixing cavities (4) are communicated with the annular space, and a smoke port group is arranged on the periphery of the small-diameter section;

a plurality of first-stage gas spray guns (3), wherein one first-stage gas spray gun (3) correspondingly penetrates through each premixing cavity (4);

and the secondary gas spray gun (5) is axially arranged in the circulation sleeve (8) in a penetrating manner, and the outlet end of the secondary gas spray gun (5) is arranged outside the circulation sleeve (8) and faces to the second end of the combustion chamber (6).

2. The gas burner according to claim 1, characterized in that a plurality of said premixing chambers (4) are distributed at intervals along the circumference of said large diameter section.

3. The gas burner according to claim 2, characterized in that said group of flue gas ports is a plurality of groups, a plurality of said groups of flue gas ports being in one-to-one correspondence with the positions of a plurality of said premixing chambers (4).

4. The gas burner according to claim 3, characterized in that each group of flue gas ports comprises a flue gas main flow guiding hole (9) and a flue gas secondary flow guiding hole (10), the flue gas main flow guiding hole (9) and the flue gas secondary flow guiding hole (10) are arranged at intervals along the axial direction of the circulation sleeve (8), and the diameter of the flue gas main flow guiding hole (9) is larger than that of the flue gas secondary flow guiding hole (10).

5. The gas burner of claim 4, wherein the main flue gas guiding hole (9) is located at a first end of the small diameter section, the plurality of secondary flue gas guiding holes (10) are provided, and the plurality of secondary flue gas guiding holes (10) are uniformly distributed at intervals between the main flue gas guiding hole (9) and a second end of the small diameter section.

6. The gas burner according to claim 1, characterized in that the first section opening diameter of the combustion chamber (6) is larger than the second end opening diameter of the combustion chamber (6), and the junction of the second end opening of the combustion chamber (6) and the inner cavity wall is provided with an arc-shaped guide structure.

7. The gas burner of claim 1, wherein the jet velocity of the primary gas injection lance (3) is 40-200 m/s, and the primary gas proportion at the primary gas injection lance (3) is 50-90%.

8. The gas burner of claim 1, wherein the jet velocity of the secondary gas lance (5) is 60-150 m/s, and the proportion of the secondary gas at the secondary gas lance (5) is 10-50%.

9. Gas burner according to claim 1, characterized in that it further comprises an air line (1) connected to each of said premixing chambers (4).

10. Gas burner according to claim 1, characterized in that it further comprises a gas conduit (2) connected both to said secondary gas injection lance (5) and to said plurality of primary gas injection lances (3).

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