Fan-shaped flame ultralow-nitrogen combustion burner with low temperature and high temperature

Abstract

The invention discloses a low-temperature and high-temperature fan-shaped flame ultralow-nitrogen combustion burner which is characterized in that a burner block is arranged on the lower side of a body, a gas inlet and smoke exhaust channel is arranged on the upper portion of the body and communicated with a combustion channel of the burner block, and an ignition device is used for ignition; a central gas pipe is arranged, the front end of the central gas pipe is a central gas nozzle communicated with the combustion channel, and a central gas pipe control valve is arranged on the central gas pipe; a plurality of peripheral fuel nozzles are arranged on the burner block and connected with the front end of the first gas pipe, and all the peripheral fuel nozzles are located on the same side of the diameter of the central gas nozzle. According to the ultra-low-nitrogen combustion burner, all the peripheral fuel nozzles are located on the same side of the diameter of the central fuel gas nozzle and arranged on the single side, an incomplete combustion area of the peripheral combustion nozzles is formed on the single side of the surface of the burner block during combustion, and the ultra-low-nitrogen combustion burner has excellent low-temperature performance of inhibiting CO generation during low-temperature combustion; and the catalyst has excellent high-temperature performance for preventing generation of NOx during high-temperature combustion.

Description

Technical Field

[0001] This invention relates to the field of industrial heating furnace technology, specifically to a fan-shaped flame ultra-low nitrogen combustion burner that combines low and high temperatures. Background Technology

[0002] Considering stringent environmental protection requirements and heating efficiency, industrial furnaces for heating workpieces are increasingly adopting regenerative combustion, i.e., regenerative combustion industrial furnaces.

[0003] Regenerative thermal ignition (RTI) industrial furnaces can heat ambient air in a short time. The heated air enters the furnace and entrains surrounding flue gas, forming a lean, high-temperature gas stream with an oxygen content significantly lower than 21%. Simultaneously, fuel is injected near this lean air stream, where combustion occurs in a low-oxygen (2%–20%) environment. Meanwhile, the hot flue gas from combustion is exhausted through another RTI burner, storing its sensible heat in that burner. The two RTI burners operate in alternating heat storage and release states, thus achieving energy savings.

[0004] In existing regenerative combustion industrial furnaces, when used at low temperatures, the preheated air and furnace gas mix inside the furnace and the temperature drops below a certain value. When the air preheating temperature is lower than the HTAC temperature, the conventional theory suggests that the air preheating temperature should be higher than the HTAC temperature. This makes incomplete combustion of the regenerative burner very likely, resulting in a large amount of CO in the furnace gas. This not only wastes fuel but also causes harmful CO emissions to humans.

[0005] In existing regenerative combustion industrial furnaces, the central burner ignites at a low temperature, gradually increasing the furnace temperature. Once the furnace reaches a certain temperature, the temperature of the furnace or flue gas is higher than the ignition point of the fuel, so the gas does not need to be ignited; the gas entering the furnace or burner combustion channel through the fuel pipe can spontaneously combust. Regenerative combustion industrial furnaces operating at higher temperatures are more prone to producing large amounts of NOx. Existing technologies typically employ flat-flame combustion, forming a near-disc-shaped flame. However, due to the high temperature of the combustion furnace, the NOx produced, especially thermal NOx, remains high, causing the NOx content in the furnace gas to exceed national or local emission standards. This necessitates additional treatment of the furnace gas, increasing the operating cost of the furnace and requiring additional investment in equipment for gas treatment. Summary of the Invention

[0006] To address the shortcomings of the existing technology, the technical problem to be solved by this invention is: how to provide a fan-shaped flame ultra-low NOx combustion burner that combines low and high temperatures, so that in the low-temperature combustion stage of regenerative combustion industrial furnaces, incomplete combustion can be reduced, preventing the generation of large amounts of harmful CO in the furnace gas; and in the high-temperature stage, NOx generated during combustion can be significantly reduced, meeting national or local emission standards for direct emission.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A fan-shaped flame ultra-low nitrogen combustion burner that combines low temperature and high temperature features includes a body, a burner brick on the lower side of the body, a combustion channel inside the burner brick, an air intake and exhaust channel on the upper part of the body that communicates with the combustion channel, a heat storage body inside the air intake and exhaust channel, and an ignition device for igniting the gas in the combustion channel; characterized in that a central gas pipe is provided, the front end of which is a central gas nozzle that communicates with the combustion channel, and a central gas pipe control valve is provided on the central gas pipe; Several peripheral fuel nozzles are set on the burner brick. The front end of the first gas pipe is connected to the peripheral fuel nozzles to pass gas into each peripheral fuel nozzle. The peripheral combustion nozzles are arranged around the central gas nozzle, and all peripheral fuel nozzles are located on the same side of the diameter or the extension line of the diameter of the central gas nozzle.

[0008] Thus, in the ultra-low NOx combustion burner of the present invention, all peripheral fuel nozzles are located on the same side of the diameter of the central gas nozzle, and are arranged on one side. During combustion, an incomplete combustion area of ​​peripheral combustion nozzles is formed on one side of the burner brick surface. It has excellent low-temperature performance in suppressing CO generation during low-temperature combustion and excellent high-temperature performance in preventing NOx generation during high-temperature combustion.

[0009] Furthermore, the peripheral combustion nozzles have the same diameter in the circumferential direction around the central gas nozzle, forming a concentric circle structure.

[0010] Furthermore, the peripheral combustion nozzle is located on the left, right, upper, or lower side of the burner brick.

[0011] Furthermore, when the gas is introduced for combustion, all peripheral combustion nozzles form an incomplete combustion zone on one side of the burner brick surface.

[0012] Furthermore, the incomplete combustion area of ​​the peripheral combustion nozzle is a fan-shaped area no larger than 180º.

[0013] In summary, the beneficial effects of the present invention are as follows: 1. The ultra-low nitrogen combustion burner of the present invention has excellent low-temperature performance in suppressing CO generation; by setting a central fuel pipe and a central combustion nozzle on the burner brick, the method of inputting gas through the central fuel pipe and combustion through the central combustion nozzle in the low-temperature stage can largely avoid the phenomenon of incomplete combustion, avoid the generation of a large amount of CO in the furnace gas, and prevent the harmful effects of emitted CO on people; it can also save fuel and improve combustion efficiency.

[0014] 2. The ultra-low NOx combustion burner of the present invention has excellent high-temperature performance in preventing NOx generation; around the central combustion nozzle in the middle part, several peripheral combustion nozzles are set. All of these peripheral combustion nozzles are located on the same side of the diameter of the central combustion nozzle, that is, all peripheral combustion nozzles are set on one side of the burner brick. When the gas ejected from these peripheral combustion nozzles burns, it forms a fan-shaped area, which is a fan-shaped area of ​​less than 180º.

[0015] 2. After the control valve of the first gas pipe of the present invention is opened, fuel flows out from the peripheral combustion nozzle set on one side of the burner brick. The fuel supply on this side is 100% of the set amount of gas, while the air supply to the gas supply area is only <50%. This side area is in an oxygen-deficient state, forming an incomplete combustion flame area. Because the flame temperature of incomplete combustion of gas is relatively low, the NOx generation is very low. On the opposite side, the burner area without a peripheral combustion nozzle is supplied with air mixed with furnace gas with an oxygen content of about 3% to form a low-oxygen state. The maximum oxygen content = (21% (air oxygen content) + furnace gas oxygen content) / 2. Taking the furnace gas oxygen content of 3% as an example, the oxygen content of the low-oxygen gas is only about 12%, which is far lower than the normal oxygen content of air of 21%. According to the High Temperature Air Combustion (HTAC) theory, when the air preheating temperature reaches above 800℃, the fuel can burn completely in a low-oxygen environment with an oxygen content of only 3%. Low-oxygen combustion inhibits the formation of thermal NOx, producing extremely low NOx levels that meet national or local emission standards and can be directly emitted.

[0016] 4. The ultra-low NOx combustion burner of this invention has been tested and found to reduce NOx emissions to below 50mg, demonstrating excellent NOx reduction effects. The current minimum local standard for NOx emissions is 100mg, while the present invention's level of below 50mg allows for direct emission; no additional treatment of the furnace gas is required, reducing the operating cost of the combustion furnace and eliminating the need for additional furnace gas treatment equipment. Attached Figure Description

[0017] Figure 1 This is a schematic diagram (cross-sectional view) of the burner structure of the present invention. Figure 2 yes Figure 1 Sectional view along line A-A; Figures 3-1, 3-2, 3-3, and 3-4 are diagrams of four embodiments of the present invention with one side configured (direction B). Figures 4-1, 4-2, 4-3, and 4-4 are schematic diagrams of the fan-shaped flames formed in the four embodiments of the present invention.

[0018] 1—Body, 2—Burner brick, 3—Combustion channel, 4—Intake and exhaust channel, 5—Heat storage body, 6—Blowbox, 7—Central gas pipe, 8—Central gas nozzle, 9—Central gas pipe control valve, 10—Ignition device, 11—Flame monitoring device, 15—Peripheral combustion nozzle, 16—First gas pipe, 17—First gas pipe control valve, 100—Incomplete combustion area of ​​peripheral combustion nozzle. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0020] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the figures, or the orientation or positional relationship commonly used when the product is in use. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. In addition, the terms "horizontal," "vertical," etc., do not indicate that the component is required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] Example: The present invention provides a fan-shaped flame ultra-low nitrogen combustion burner that combines low and high temperature characteristics, such as... Figure 1 , 2 As shown.

[0022] The furnace includes a main body 1, with a burner brick 2 on its lower side. A combustion channel 3 is provided inside the burner brick 2. An air intake and exhaust channel 4 is provided on the upper part of the main body 1, and a heat storage body 5 is installed inside the air intake and exhaust channel 4. The air intake and exhaust channel 4 serves as the inlet channel for combustion air or the outlet channel for flue gas in a regenerative alternating combustion system, and it is connected to the combustion channel 3. The end of the combustion channel 3 facing the furnace is typically shaped like a funnel to facilitate the formation of a flat flame combustion state on the surface of the burner brick 2 after combustion. Some industrial furnaces have a bellows 6 installed at the upper end of the air intake and exhaust channel 4, through which combustion air enters the air intake and exhaust channel 4. The above is prior art and will not be further described here.

[0023] The ultra-low nitrogen flat flame burner of this invention features a central gas pipe 7, with a central gas nozzle 8 at its front end connected to a combustion channel 3. Fuel input through the central gas pipe 7 is mixed with combustion air introduced through the intake and exhaust channels 4 within the combustion channel 3. An ignition device 10, extending deep into the combustion channel 3 and close to the central gas nozzle 8, ignites the combustible mixture under the ignition spark of the ignition device 10. A central gas pipe control valve 9 is installed on the central gas pipe 7, electrically connected to a control device. Under the control of the control device, the valve 9 is opened or closed to control the volume of combustible gas passing through the central gas pipe 7, meeting the requirements of the combustion process. The central gas nozzle 8 is typically located in the middle of the burner brick 2. A flame monitoring device 11 is installed within the combustion channel 3, or near the central gas nozzle 8, to monitor whether the fuel ejected from the central gas nozzle 8 is ignited, i.e., whether there is a flame within the combustion channel 3.

[0024] Several peripheral fuel nozzles 15 are set on the burner brick 2. The front end of the first gas pipe 16, which inputs gas into the combustion furnace, is connected to the peripheral fuel nozzles 15, so that the gas is passed into each peripheral fuel nozzle 15 and then injected into the furnace. The peripheral combustion nozzles 15 are arranged around the central gas nozzle 8 (combustion channel 3), and all the peripheral fuel nozzles 15 are located on the same side of the diameter (or the extension line of the diameter) of the central gas nozzle 8, that is, all the peripheral fuel nozzles 15 are set on one side of the burner brick; as shown in the figure, several peripheral combustion nozzles 15 are arranged with equal diameters in the circumferential direction around the central gas nozzle 8, forming a concentric circle structure.

[0025] This invention provides a plurality of peripheral combustion nozzles 15 arranged on one side of the burner brick 2 around the central gas nozzle 8. These nozzles can be arranged in various configurations, such as on the left, right, upper, or lower side of the burner brick 2, as long as the number meets the process requirements of industrial furnace combustion. As shown in Figure 4, when gas is introduced for combustion, all the peripheral combustion nozzles 15 arranged on one side of the burner brick 2 form a fan-shaped combustion area on one side of the burner brick 2 surface. This fan-shaped area, specifically the incomplete combustion area 100 of the peripheral combustion nozzles, is no larger than 240º, and is typically less than 180º.

[0026] In the industrial furnace of the present invention, after ignition and during the low-temperature combustion stage, after the central gas pipe control valve 9 of the central gas pipe 7 is opened, fuel flows out from the central peripheral combustion nozzle 15. In the combustion channel 3, the fuel mixes with the gas introduced from the air intake and exhaust channel 4 and is ignited under the action of the ignition device 10 generating an ignition flame, gradually heating and providing the furnace temperature.

[0027] During the high-temperature stage, due to the high temperature inside the furnace (exceeding the process-set temperature), the central gas pipe 7 can be shut off. During the high-temperature stage, after the first gas pipe control valve 17 of the first gas pipe 16 of the present invention is opened, fuel flows out from the peripheral combustion nozzle 15 on one side. The fuel supply on this side is 100% of the set amount of gas, while the air supply to the gas supply area is only <50%. This side area is in an oxygen-deficient state, forming an incomplete combustion flame area, as shown in the fan-shaped area in Figure 4. Because the flame temperature of incomplete combustion is relatively low, the NOx generation is very low. On the opposite side, in the burner area where no combustion nozzle is set, the supplied air mixes with the furnace gas with an oxygen content of about 3% to form a low-oxygen state. The maximum oxygen content = (21% (air oxygen content) + furnace gas oxygen content) / 2. Taking the furnace gas oxygen content of 3% as an example, the oxygen content of the low-oxygen gas is only about 12%, which is far lower than the normal oxygen content of air of 21%. According to the High Temperature Air Combustion (HTAC) theory, when the air preheating temperature reaches above 800℃, the fuel can burn completely in a low-oxygen environment with an oxygen content of only 3%. Low-oxygen combustion inhibits the formation of thermal NOx, producing extremely low NOx levels that meet national or local emission standards and can be directly emitted.

[0028] Therefore, the fan-shaped flame ultra-low NOx combustion burner of the present invention, which combines low temperature and high temperature, has excellent low-temperature performance in suppressing CO generation during low-temperature combustion and excellent high-temperature performance in preventing NOx generation during high-temperature combustion.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described with reference to preferred embodiments, those skilled in the art should understand that various changes in form and detail can be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A fan-shaped flame ultra-low nitrogen combustion burner that combines low temperature and high temperature, comprising a body (1), the present invention The lower side of the body (1) is a burner brick (2), and a combustion channel (3) is provided inside the burner brick (2). The air intake and exhaust channel (4) provided on the upper part of the body (1) is connected to the combustion channel (3). The ignition device (10) is used to ignite the gas in the combustion channel (3); characterized in that, A central gas pipe (7) is provided, with a central gas nozzle (8) at its front end connected to the combustion channel (3). A central gas pipe control valve (9) is provided on the central gas pipe (7). Several peripheral fuel nozzles (15) are set on the burner brick (2). The front end of the first gas pipe (16) is connected to the peripheral fuel nozzles (15) to pass gas into each peripheral fuel nozzle (15). The peripheral combustion nozzles (15) are set around the central gas nozzle (8). All peripheral fuel nozzles (15) are located on the same side of the diameter or diameter extension line of the central gas nozzle (8).

2. The fan-shaped flame ultra-low nitrogen combustion burner with both low and high temperature characteristics according to claim 1, characterized in that, The peripheral combustion nozzles (15) have the same diameter in the circumferential direction as the central gas nozzle (8), forming a concentric circle structure.

3. The fan-shaped flame ultra-low nitrogen combustion burner with both low and high temperature characteristics according to claim 1, characterized in that, The peripheral combustion nozzle (15) is located on the left, right, upper or lower side of the burner brick (2).

4. The fan-shaped flame ultra-low nitrogen combustion burner with both low and high temperature characteristics according to any one of claims 1-3, characterized in that, When the gas is introduced for combustion, all peripheral combustion nozzles (15) form an incomplete combustion zone (100) on one side of the burner brick (2) surface.

5. The fan-shaped flame ultra-low nitrogen combustion burner with both low and high temperature characteristics according to claim 4, characterized in that, The incomplete combustion area (100) of the peripheral combustion nozzle is a fan-shaped area no larger than 240º.

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