Low-nitrogen burner for low-heating-value gas

Abstract

The utility model discloses a low-nitrogen burner for low-heating-value gas. The low-nitrogen burner comprises an ignition gun, an ignition gas gun, a burner body, a nozzle and an air bellow. The ignition gun and the ignition gas gun are installed at one end of the burner body, the nozzle is installed at the other end of the burner body, a plurality of gas channels are arranged on the burner body at intervals in the length direction of the burner body, and the ignition gas gun and the gas channels are all matched with air inlet channels. The multiple air inlet channels are arranged on the burner body at intervals, and the air bellow is installed on the burner body. According to the low-nitrogen combustor for the low-heating-value gas, the problem that the low-heating-value gas cannot be combusted autonomously and stably can be effectively solved, and oxynitride generated by combustion of the low-heating-value gas can be reduced; the low-heat-value gas combustion can be utilized to bake the furnace, and the low-nitrogen emission requirement can be met.

Description

Technical Field

[0001] The utility model relates to the technical field of burners, in particular to a low-nitrogen burner for low-calorific-value gas. Background Technique

[0002] At present, some low-calorific-value by-product fuel gases are generated in some steel plants or chemical plants, such as blast furnace gas, analytical gas, purge gas, or other industrial tail gases mainly composed of CO and H2. These gases have low calorific values, usually in the range of 800 - 1500 Kcal / Nm 3 , with a pressure of 3 - 10 Kpa, and cannot burn stably and sustainably. Usually, other gases are required as ignition gas guns for ignition startup. After the furnace temperature reaches above 800 °C, the high-calorific-value gas ignition gas gun can be removed. At the same time, low-nitrogen requirements for this type of gas are put forward, and in some areas, the nitrogen oxide emission is required to be lower than 50 mg / Nm 3 .

[0003] For newly built boilers, it is often necessary to carry out furnace drying. If these low-calorific-value gases can be used as fuels for furnace drying and can meet the low-nitrogen emission requirements, it will bring great benefits to environmental protection and economic benefits.

[0004] Based on this, a low-nitrogen burner for low-calorific-value gas is proposed to solve the above problems. Content of the Utility Model

[0005] The purpose of the utility model is to provide a low-nitrogen burner for low-calorific-value gas, realizing the stable combustion of low-calorific-value gas and low-nitrogen emission after combustion.

[0006] To solve the above technical problems, the utility model provides a low-nitrogen burner for low-calorific-value gas, including an ignition gun, an ignition gas gun, a burner body, a nozzle, and an air box. The ignition gun and the ignition gas gun are installed at one end of the burner body, and the nozzle is installed at the other end of the burner body. The ignition gas gun is used to input high-calorific-value combustion gas into the burner body. A plurality of gas channels are arranged at intervals along the length direction of the burner body for hierarchically inputting low-calorific-value combustion gas into the burner body. The ignition gas gun and the plurality of gas channels are all equipped with air inlet channels, and the plurality of air inlet channels are arranged at intervals on the burner body for hierarchically inputting low-oxygen combustion-supporting air into the burner body. The air box is installed on the burner body to provide oxygen-rich combustion-supporting air for the inner side and the periphery of the nozzle.

[0007] Further, the nozzle has a contraction part, and both ends of the contraction part expand outwards to form expansion parts in the shape of a frustum of a cone.

[0008] Further, spray nozzles are provided in both the gas passage and the air supply passage, and the spray nozzles adopt swirl vanes.

[0009] Further, the swirl directions of the spray nozzles in the gas passage and the air supply passage are the same.

[0010] Further, a plurality of air supply pipes are connected to the air outlet of the air box, and the plurality of air supply pipes are spaced around the periphery of the nozzle.

[0011] Further, a manual regulating damper is provided in the air box.

[0012] Further, a manual regulating damper is provided on the air supply pipe.

[0013] Further, an automatic regulating damper is provided at the air inlet of the air box.

[0014] Compared with the prior art, the utility model has at least the following beneficial effects:

[0015] The low-nitrogen burner for low-calorific-value gas provided by the utility model can effectively solve the problem that low-calorific-value gas cannot burn stably by itself, and can reduce nitrogen oxides generated by the combustion of low-calorific-value gas; that is, it realizes the ability to use the combustion of low-calorific-value gas for furnace drying and can meet the low-nitrogen emission requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is the front view of the overall structure diagram of the low-nitrogen burner for low-calorific-value gas of the utility model;

[0017] Figure 2 is the top view of the overall structure diagram of the low-nitrogen burner for low-calorific-value gas of the utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The low-nitrogen burner for low-calorific-value gas of the utility model will be described in more detail below with reference to the schematic diagrams, in which the preferred embodiments of the utility model are shown. It should be understood that those skilled in the art can modify the utility model described herein while still achieving the beneficial effects of the utility model. Therefore, the following description should be understood as a broad guidance for those skilled in the art and not as a limitation to the utility model.

[0019] The utility model will be described more specifically by way of example in the following paragraphs with reference to the drawings. The advantages and features of the utility model will be clearer according to the following description and the claims. It should be noted that the drawings are all in a very simplified form and use non-precise scales, only for the purpose of facilitating and clearly assisting in explaining the embodiments of the utility model.

[0020] Such as Figure 1-2As shown in the figure, an embodiment of the present utility model provides a low-nitrogen burner for low-calorific-value gas, which includes an ignition gun 1, an ignition gas gun 2, a burner body 3, a nozzle 4, and an air box 5. One end of the burner body 1 is installed with the ignition gun 1 and the ignition gas gun 2, and the other end of the burner body 3 is installed with the nozzle 4. A plurality of gas channels 031 are arranged at intervals along the length direction of the burner body 3. The ignition gas gun 2 and the plurality of gas channels 031 are each equipped with an air inlet channel 032. The plurality of air inlet channels 032 are arranged at intervals on the burner body 3, and the air box 5 is installed on the burner body.

[0021] Specifically, the ignition gas gun 2 is used to input high-calorific-value combustion gas into the burner body 3. The plurality of gas channels 031 are used to input low-calorific-value combustion gas into the burner body 3 in a staged manner. The plurality of air inlet channels 032 are used to input low-oxygen combustion-supporting air into the burner body 3 in a staged manner. The outlet of the air box 5 is connected to a plurality of air supply pipes 6. The plurality of air supply pipes 6 are arranged around the nozzle 4 at intervals. One end of the air supply pipe 6 is open, and the other end is communicated with the inside of the burner body 3. When the air box 5 is started, it can provide oxygen-rich combustion-supporting air for the inside and the periphery of the nozzle 4.

[0022] For the convenience of explanation, the number of the air inlet channels 032 and the gas channels 031 is defined here. For example, Figure 1 in the figure, the air inlet channels 032 are set to three, which are the ignition gas gun air inlet channel, the gas primary air inlet channel, and the gas secondary air inlet channel from left to right in sequence; the gas channels are set to two, which are the primary gas channel and the secondary gas channel from left to right respectively.

[0023] The burner body 1 is installed on the furnace body. The air supply pipes 6 are integrally formed with high-temperature refractory castable and embedded in the furnace body. During the furnace drying operation, first, the high-calorific-value combustion gas is introduced into the burner body 3 through the ignition gas gun 2. At the same time, the ignition gas gun air inlet channel inputs low-oxygen combustion-supporting air, and the ignition gun 2 is started for ignition to realize the lean-oxygen combustion of the high-calorific-value combustion gas. Then, the low-calorific-value combustion gas is divided into two levels and sequentially input into the primary gas channel and the secondary gas channel. While the primary gas channel and the secondary gas channel input the low-calorific-value combustion gas, the gas primary air inlet channel and the gas secondary air inlet channel correspondingly input low-oxygen combustion-supporting air, realizing the staged lean-oxygen combustion of the low-calorific-value combustion gas. Finally, the air box 5 is enabled, and oxygen-rich combustion-supporting air is transported to the inside and the outside of the nozzle 4 through the air supply pipes 6 to realize oxygen-rich combustion.

[0024] In the above implementation process, the high calorific value combustion gas is used as the ignition fuel for the first stage of oxygen-depleted combustion, and then the low calorific value combustion gas is used for the two-stage oxygen-depleted combustion, which can achieve stable temperature rise in the initial furnace baking stage, ensure the furnace baking quality, and effectively reduce nitrogen emissions. The final oxygen-rich combustion can reduce the temperature of the combustion area and achieve an overall reduction in nitrogen oxide emissions. Furthermore, since the air supply pipe 6 transports oxygen-rich combustion air to the outside of the nozzle 4, the flame combustion area can be increased, thereby achieving a better combustion effect.

[0025] In the above embodiment, preferably, in order to stabilize the flame, a contraction portion is provided in the casting material of the nozzle 4, and both ends of the contraction portion expand outward to form a truncated cone-shaped expansion portion. Furthermore, during operation, the temperature of the nozzle will exceed 1000°C, so the material of the nozzle 4 is heat-resistant steel 310S.

[0026] In the above embodiment, in order to adjust the air volume ratio of the oxygen-enriched combustion-supporting air entering the nozzle 4 and the air supply pipe 6 , a manually adjustable damper 8 is provided in the wind box 5 .

[0027] In the above embodiment, preferably, in order to ensure sufficient mixing between the fuel gas and the combustion-supporting air, swirl blade-shaped nozzles (not shown in the figure) are arranged in the gas channel 031 and the air supply channel 032, wherein the swirl directions of the nozzles in the gas channel 031 and the air supply channel 032 are the same.

[0028] In the above embodiment, the air inlet of the bellows 5 is provided with an automatically adjustable damper 7 to realize automatic adjustment of the air flow rate of the bellows 51 .

[0029] In summary, the low-nitrogen burner for low calorific value gas provided by the utility model can effectively solve the problem that low calorific value gas cannot burn independently and stably, and can reduce the nitrogen oxides produced by the combustion of low calorific value gas; that is, it can realize the use of low calorific value gas combustion to bake the furnace and meet the low nitrogen emission requirements.

[0030] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A low-nitrogen burner for low calorific value gas, characterized in that, It includes an ignition gun, an ignition gas gun, a burner body, a nozzle, and a wind box; The ignition gun and the ignition gas gun are installed at one end of the burner body, and the nozzle is installed at the other end of the burner body; The ignition gas gun is used to input high-calorific combustion gas into the burner body; A plurality of gas channels are arranged at intervals along the length direction of the burner body for hierarchically inputting low-calorific combustion gas into the burner body; The ignition gas gun and the plurality of gas channels are all provided with air inlet channels, and the plurality of air inlet channels are arranged at intervals on the burner body for hierarchically inputting low-oxygen combustion-supporting air into the burner body; The wind box is installed on the burner body to provide oxygen-rich combustion-supporting air for the inner side and the periphery of the nozzle; 2. The low-nitrogen burner for low calorific value gas according to claim 1, characterized in that, The nozzle has a contraction part, and both ends of the contraction part expand outwards to form frustum-shaped expansion parts; 3. The low-nitrogen burner for low calorific value gas according to claim 1, characterized in that, Spray heads are arranged in both the gas channel and the air supply channel, and the spray heads adopt swirl vanes; 4. The low-nitrogen burner for low calorific value gas according to claim 3, characterized in that, The swirl directions of the spray heads in the gas channel and the air supply channel are the same; 5. The low-nitrogen burner for low-calorific value gas according to claim 1, characterized in that, The air outlet of the wind box is communicated with a plurality of air supply pipes, and the plurality of air supply pipes are arranged around the periphery of the nozzle at intervals; 6. The low-nitrogen burner for low calorific value gas according to claim 5, characterized in that, A manual regulating air damper is arranged in the wind box; 7. The low-nitrogen burner for low calorific value gas according to claim 1, characterized in that, An automatic regulating air damper is arranged at the air inlet of the wind box.

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