Partially premixed flue gas internal circulation low-nitrogen burner

Abstract

The utility model relates to the technical field of combustors, and discloses a partially premixed flue gas internal circulation low-nitrogen combustor which comprises an air channel and a central fuel gas channel, a peripheral fuel gas chamber is arranged at the inner bottom end of the air channel, a peripheral fuel gas inlet is fixedly connected to the front end of the peripheral fuel gas chamber, and the central fuel gas channel is communicated with the peripheral fuel gas inlet. An air contraction opening is formed in the top side of the air channel, a plurality of peripheral gas injection pipes are fixedly connected to the top end of the peripheral gas chamber, and the top sides of the peripheral gas injection pipes penetrate through the top side of the outer wall of the air contraction opening and are fixedly connected with an annular cavity. According to the utility model, the central injection pipe is arranged to be a bent pipe for outward injection, so that central fuel gas and air are fully mixed and combusted, the robustness of central flame is improved, and meanwhile, a plurality of holes are formed in the front end of the annular chamber, so that flue gas in a hearth and peripheral fuel gas are fully mixed in the annular chamber, and the temperature of peripheral flame is reduced; and the effect of reducing nitrogen oxides is achieved.

Description

Technical Field

[0001] This utility model relates to the field of burner technology, and in particular to a partially premixed flue gas internal circulation low-NOx burner. Background Technology

[0002] Industrial burners play a vital role in modern industry, widely used in energy production, chemical, metallurgical, papermaking, and ceramics industries. However, with increasingly stringent national environmental policies, demands for higher energy efficiency, and technological advancements, industrial burners face numerous challenges, such as low combustion efficiency, emission control, and the stability and control of the combustion process. Current burner designs must closely comply with national environmental regulations, achieving high efficiency while maintaining low pollutant emissions. This presents a contradiction between operational stability and low-emission operation. Therefore, it is necessary to optimize existing burner structures to further balance combustion stability and low pollutant emissions. Current nitrogen reduction technologies used in industrial burner design mainly include external flue gas recirculation, diffusion combustion, fuel-air staged combustion, rich-lean combustion, and premixed combustion. However, a single combustion technology is insufficient to achieve a balance between low emissions and stability. Therefore, to achieve stable low-NOx combustion, this invention combines multiple technologies such as fuel-air staged combustion, internal flue gas recirculation, fuel-air premixing, and rich-lean combustion to design a burner that achieves complete fuel combustion, low NOx emissions, and highly stable operation.

[0003] Currently, most industrial burners use a single combustion technology, making it difficult for them to achieve a balance between low emissions and stability. This results in excessive emissions or low efficiency. To address this technical problem, this application proposes a partially premixed flue gas recirculation low-NOx burner. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a partially premixed flue gas internal circulation low-NOx burner, which aims to solve the problems of high NOx emissions, incomplete combustion, and unstable combustion in commonly used industrial boiler gas burners.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A partially premixed flue gas recirculation low-NOx burner includes an air passage and a central gas passage. An outer gas chamber is located at the bottom of the air passage, and an outer gas inlet is fixedly connected to the front end of the outer gas chamber. An air contraction port is located on the top side of the air passage. Multiple outer gas ejector pipes are fixedly connected to the top of the outer gas chamber. The top side of each outer gas ejector pipe penetrates the top wall of the air contraction port and is fixedly connected to an annular chamber. A front expansion port is located on the bottom side of the annular chamber, and multiple small holes are located at the bottom end of the front expansion port. Multiple bent-tube injection pipes are fixedly connected to the top side of the central gas passage.

[0007] Furthermore, a flame stabilizer is fixedly connected to the top of the outer wall of the curved jet pipe, and multiple air holes are opened on the top side of the flame stabilizer.

[0008] Furthermore, a central flame hood is fixedly connected to the outer wall of the flame stabilizing disc.

[0009] Furthermore, a central partition is fixedly connected inside the annular chamber, and multiple peripheral annular injection pipes are fixedly connected to the top side of the annular chamber.

[0010] Furthermore, the number of the curved injection pipes is four to eight.

[0011] Furthermore, the number of peripheral gas ejector tubes is four to eight.

[0012] Furthermore, the number of the peripheral annular cavity injection pipes is six to sixteen.

[0013] Furthermore, the number of air holes is six to thirty.

[0014] This utility model has the following beneficial effects:

[0015] 1. In this utility model, by setting the central injection pipe as a curved pipe to inject outward, the central combustion gas and air are fully mixed and combusted, improving the stability of the central flame. At the same time, by setting several holes at the front end of the annular chamber, the flue gas in the furnace and the external combustion gas are fully mixed in the annular chamber, reducing the temperature of the external flame and achieving the effect of reducing nitrogen oxides.

[0016] 2. In this utility model, by dividing the gas into central gas and peripheral gas, and classifying the air through the central flame hood, the burner can achieve uniform and stable combustion in the furnace while reducing nitrogen oxide emissions. Attached Figure Description

[0017] Figure 1 This is a perspective view of a partially premixed flue gas internal recirculation low-NOx burner proposed in this utility model;

[0018] Figure 2This is a schematic diagram of the internal structure of a partially premixed flue gas internal circulation low-NOx burner proposed in this utility model;

[0019] Figure 3 This is a schematic diagram of the front structure of a partially premixed flue gas internal circulation low-NOx burner proposed in this utility model;

[0020] Figure 4 This is a schematic diagram of the flame stabilizer structure of a partially premixed flue gas internal circulation low-NOx burner proposed in this utility model.

[0021] Legend:

[0022] 1. External gas inlet; 2. Air contraction port; 3. Annular chamber; 4. Central gas passage; 5. Bent-type injection pipe; 6. Flame stabilizer; 7. External annular injection pipe; 8. External gas ejector pipe; 9. Air passage; 10. External gas chamber; 11. Central gas passage; 12. Middle partition; 13. Front expansion and contraction port; 14. Central flame hood; 15. Air hole. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] Reference Figure 1-3 This utility model provides an embodiment of a partially premixed flue gas internal circulation low-NOx burner, comprising an air channel 9 and a central gas channel 11. An outer gas chamber 10 is provided at the bottom of the air channel 9, and an outer gas inlet 1 is fixedly connected to the front end of the outer gas chamber 10. An air contraction port 2 is provided on the top side of the air channel 9 to accelerate air ejection, allowing air and gas to mix fully at the top. Multiple outer gas ejector pipes 8 are fixedly connected to the top of the outer gas chamber 10. The top side of the outer gas ejector pipes 8 penetrates the top side of the outer wall of the air contraction port 2 and is fixedly connected to an annular chamber 3. A front end expansion port 13 is provided on the bottom side of the annular chamber 3, and multiple small holes are provided at the bottom end of the front end expansion port 13 for absorbing entrained flue gas. The entrained flue gas is mixed with the outer gas in the annular chamber 3 to reduce nitrogen oxides. Multiple curved injection pipes 5 are fixedly connected to the top side of the central gas channel 11, allowing the central gas to be dispersed and fully mixed with the surrounding air for combustion, greatly improving combustion stability.

[0025] Reference Figure 1 , Figure 2 and Figure 4A flame stabilizer 6 is fixedly connected to the top of the outer wall of the curved injection pipe 5. Multiple air holes 15 are opened on the top side of the flame stabilizer 6 to classify the air flowing into the central flame hood 14, so that the gas and air are mixed and burned at the same time, which greatly improves the combustion efficiency and reduces the emission of nitrogen oxides. The central flame hood 14 is fixedly connected to the outer wall of the flame stabilizer 6, which plays the role of further classifying the air and saturating the central flame, so that the central flame burns stably. A middle partition 12 is fixedly connected inside the annular chamber 3. Multiple peripheral annular injection pipes 7 are fixedly connected to the top side of the annular chamber 3. The number of curved injection pipes 5 is four to eight, the number of peripheral gas ejector pipes 8 is four to eight, and the number of peripheral annular injection pipes 7 is six to sixteen.

[0026] Working principle: During use, gas is supplied to both the outer gas inlet 1 and the central gas channel 11. The gas supplied to the central gas channel 11 is ejected through the curved injection pipe 5 on the top side of the central gas channel 11. The gas supplied to the outer gas chamber 10 enters the annular chamber 3 through the outer gas ejector pipe 8. Since the central partition 12 separates the annular chamber 3, the gas supplied into the annular chamber 3 is ejected through the small hole on the bottom side of the front expansion port 13. When the gas ejected from the curved injection pipe 5 is ignited, it is blocked by the central flame shroud 14, thereby achieving the effect of air classification and central flame smothering.

[0027] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A partially premixed flue gas recirculating low-NOx combustor comprising an air passage (9) and a central gas passage (11), characterized in that: The inner bottom end of the air channel (9) is provided with a peripheral gas chamber (10), the front end of the peripheral gas chamber (10) is fixedly connected with a peripheral gas inlet (1), the top side of the air channel (9) is provided with an air contraction port (2), the top end of the peripheral gas chamber (10) is fixedly connected with a plurality of peripheral gas injection pipes (8), the top side of the peripheral gas injection pipe (8) penetrates the outer wall top side of the air contraction port (2) and is fixedly connected with a ring cavity (3), the bottom side of the ring cavity (3) is provided with a front end expansion port (13), the bottom end of the front end expansion port (13) is provided with a plurality of small holes, and the top side of the central gas channel (11) is fixedly connected with a plurality of elbow type injection pipes (5).

2. A partially premixed flue gas recirculation low-NOx burner according to claim 1, wherein: The outer wall top end of the elbow type injection pipe (5) is fixedly connected with a flame stabilizing disc (6), and the top side of the flame stabilizing disc (6) is provided with a plurality of air holes (15).

3. A partially premixed flue gas recirculation low-NOx burner according to claim 2, wherein: The outer wall of the flame stabilizing disc (6) is fixedly connected with a central fire ring cover (14).

4. A partially premixed flue gas recirculation low-NOx burner according to claim 1, wherein: The inner part of the ring cavity (3) is fixedly connected with a middle partition plate (12), and the top side of the ring cavity (3) is fixedly connected with a plurality of peripheral ring cavity injection pipes (7).

5. A partially premixed flue gas recirculation low-NOx combustor as set forth in claim 1, characterized by: The number of the elbow type injection pipe (5) is four to eight.

6. A partially premixed flue gas recirculation low-NOx combustor as set forth in claim 1, characterized by: The number of the peripheral gas injection pipe (8) is four to eight.

7. A partially premixed flue gas recirculation low-NOx combustor as set forth in claim 4, characterized by: The number of the peripheral ring cavity injection pipe (7) is six to sixteen.

8. A partially premixed flue gas recirculation low-NOx combustor according to claim 2, wherein: The number of the air hole (15) is six to thirty.

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