A staged combustion gas ejection chemical industry low-nitrogen combustor

Abstract

The application discloses a staged combustion gas ejection chemical low-nitrogen burner, which comprises peripheral gas spray guns, main gas guns, refractory bricks, flame stabilizing discs, a shell, a gas collecting pipe, an air inlet and regulating valves. The air inlet is arranged on the side of the shell, and the regulating valves are arranged on the air inlet. The main gas guns are coaxially arranged in the shell, the flame stabilizing discs are coaxially arranged with the main gas guns, and the refractory bricks are coaxially arranged on the top flange plate of the shell. The peripheral gas spray guns are arranged on the top flange plate of the shell, the outer edges of the refractory bricks are provided with flue gas ejection channels arranged coaxially with the peripheral gas spray guns, the bottoms of the peripheral gas spray guns are connected with the gas collecting pipe, and the inner sides of the refractory bricks are provided with shunt channels arranged in parallel with the flue gas ejection channels.

Description

Technical Field

[0001] This invention relates to the field of burner technology, and specifically to a staged combustion gas ejector low-NOx burner for chemical processing. Background Technology

[0002] With the technological development of tubular furnace burners in the petrochemical industry, there is a growing demand for burners with a high heat release regulation ratio, stable flame, and emissions below industry-mandated standards. As new burner technologies continue to evolve, a burner with a high regulation ratio, stable flame, and reduced NOx emissions is needed to meet the process requirements of heating furnaces. Key technical factors include the distribution of combustion air, the opening method of the fuel gun, the design shape of the refractory bricks, and the size of the nozzle openings. The distribution of combustion air involves controlling the incoming air velocity at the refractory brick throat. The fuel injected from the fuel gun must quickly and thoroughly mix with the combustion air for intense combustion, and the amount of air required for fuel combustion must be properly matched, with the excess air coefficient controlled to a minimum. During stable combustion, the refractory bricks must have sufficient heat storage, and there should be no flameout, flame flickering, or backfire after the fuel is injected from the fuel gun.

[0003] Most existing burners employ diffusion combustion. To ensure complete combustion, burners generally use a design that achieves good fuel-air mixing. This type of combustion results in high flame temperatures and a large high-temperature zone, easily producing large amounts of NOx. Designing a burner that reduces the oxygen concentration in the tail gas, further lowers NOx, and ensures stable and complete combustion is a pressing problem for R&D personnel. Currently, NOx emission reduction is mainly achieved through staged fuel combustion, flue gas recirculation, and low-oxygen combustion technologies. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a staged combustion gas ejector low-NOx burner for chemical industries. This invention applies staged combustion of gas and internal flue gas recirculation technology to forced draft / natural draft burner technology, aiming to solve the problems of high NOx emissions and unstable combustion in commonly used chemical tubular furnace gas burners.

[0005] This invention provides a staged combustion gas ejector low-NOx chemical burner, comprising: an outer gas nozzle, a main gas nozzle, refractory bricks, a flame stabilizer, a shell, a gas collecting pipe, an air inlet, and a regulating valve; the air inlet is located on the side of the shell, and the regulating valve is located on the air inlet; the main gas nozzle is coaxially disposed inside the shell, the flame stabilizer is coaxially disposed with the main gas nozzle, and the refractory bricks are coaxially disposed on the top flange plate of the shell; the outer gas nozzle is disposed on the top flange plate of the shell, the outer edge of the refractory bricks is provided with a flue gas ejection channel coaxially arranged with the outer gas nozzle, the bottom of the outer gas nozzle is connected to the gas collecting pipe, and the inner side of the refractory bricks is provided with a diversion channel arranged parallel to the flue gas ejection channel.

[0006] Furthermore, the number of peripheral gas spray guns is 6 to 18, and the peripheral gas spray guns are radially evenly distributed around the axis of the housing.

[0007] Furthermore, the diameter of the flue gas ejector channel is 50mm to 80mm, the number of the flue gas ejector channels is the same as the number of the peripheral gas injection guns, and the flue gas ejector channels are radially evenly distributed around the axis of the housing.

[0008] Furthermore, the diameter of the diversion channel is 40mm to 60mm, the number of the diversion channels is the same as the number of the peripheral gas spray guns, and the diversion channels are radially evenly distributed around the axis of the housing.

[0009] Furthermore, the diameter of the nozzle of the peripheral gas spray gun is 3mm to 10mm.

[0010] Furthermore, the nozzle angle of the main gas gun is 45° to 75°.

[0011] This invention offers the following advantages: The present invention provides a staged combustion gas ejector low-NOx burner. Air enters the casing through the air inlet, with the opening size adjusted by a regulating valve to control the airflow. At the main gas nozzle, it mixes and burns with primary fuel gas, forming the first combustion zone. Peripheral nozzles coaxially inject fuel gas from the flue gas ejector channel. The fuel gas, through the ejector, carries in a portion of the return flue gas, which mixes with the fuel gas in the flue gas ejector channel and the diversion channel before entering the upper part of the burner. There, it mixes and burns with unburned air and flue gas from the first zone, forming the second combustion zone. By using a specially designed injection method and refractory brick structure, the mixing of fuel and air is controlled, thereby controlling the entire combustion process of the fuel gas, enhancing flame stability, controlling flame height, and reducing NOx generation. The staged combustion of air and fuel creates a multi-stage flame, lowering the flame temperature and significantly reducing NOx emissions. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is an isometric view of the staged combustion gas ejector chemical low-NOx burner of the present invention;

[0014] Figure 2 This is a top view of the staged combustion gas ejector low-NOx burner of the present invention;

[0015] Figure 3 This is a front cross-sectional view of the staged combustion gas ejector chemical low-NOx burner of the present invention;

[0016] Figure 4 This is a bottom view of the staged combustion gas ejector chemical low-NOx burner of the present invention;

[0017] Diagram description: 1-External gas spray gun; 2-Main gas gun; 3-Refractory brick; 4-Flame stabilizer plate; 5-Shell; 6-Gas collection pipe; 7-Air inlet; 8-Regulating valve; 9-Continuous light; 10-Top flange plate; 11-Fluorescence ejector channel; 12-Diverter channel. Detailed Implementation

[0018] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be pointed out that the following detailed description is illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0019] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0020] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of this application is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art. In the drawings, for clarity, the thickness of layers and regions has been enlarged, and the same reference numerals are used to denote the same devices, and therefore their description will be omitted.

[0021] Please see Figures 1 to 4 This invention provides a staged combustion gas ejector chemical low-NOx burner, comprising: an outer gas spray gun 1, a main gas gun 2, refractory bricks 3, a flame stabilizer 4, a shell 5, a gas collecting pipe 6, an air inlet 7, a regulating valve 8, a continuous lamp 9, and a top flange plate 10.

[0022] The air inlet 7 is located on the side of the housing 5, and the regulating valve 8 is located on the air inlet 7. Air enters the housing 5 through the air inlet 7 and the regulating valve 8 adjusts the opening size to control the air volume.

[0023] The main gas gun 2 is coaxially mounted inside the housing 5, the flame stabilizer 4 is coaxially mounted with the main gas gun 2, and the refractory brick 3 is coaxially mounted on the top flange plate 10 of the housing 5; the peripheral gas spray gun 1 is mounted on the top flange plate 10 of the housing 5 and is fixedly mounted on the top flange 10 of the housing 5. A continuous lamp 9 is also installed inside the housing 5 as an ignition and stable flame source.

[0024] The outer edge of the refractory brick 3 is provided with a flue gas injection channel 11 arranged coaxially with the outer gas gun 1. The bottom of the outer gas gun 1 is connected to the gas collecting pipe 6. The inner side of the refractory brick 3 is provided with a diversion channel 12 arranged parallel to the flue gas injection channel 11.

[0025] The peripheral gas spray gun 1 is used to classify the gas, spray secondary gas and induced flue gas to return; the main gas gun 2 is used to uniformly spray primary gas and form a good mixture with air; the refractory brick 3 is used to organize stable combustion and guide the diversion channel 12 of the induced flue gas and gas mixture; the flame stabilizer 4 is used to form a stable air and gas mixing area to stabilize the central combustion.

[0026] The outer gas torch 1 has an axial high-speed nozzle at its nozzle head, which sprays directly into the coaxially arranged flue gas ejection channel 11, forming a negative pressure zone to guide the flue gas back into the upper part of the burner and the diversion channel 12 of the refractory brick 3, thereby forming a multi-stage diversion of flue gas and gas mixture inside and outside; the main gas torch 2 is fixedly installed on the housing 5, including a flame stabilizer plate 4, with an upward-sloping hole at its nozzle head, which fully mixes with the air passing through the housing 5 to form a combustion zone in the middle of the inner side of the refractory brick; the flame stabilizer plate 4 is fixedly installed at the head of the main gas torch 2, with 10-12 elongated holes on the plate surface, each 30mm-40mm long and about 10mm wide, and the plate diameter is about 250mm.

[0027] In this embodiment, the number of peripheral gas spray guns 1 is 6 to 18, and the peripheral gas spray guns 1 are radially evenly distributed around the axis of the housing 5. The diameter of the flue gas ejector channel 11 is 50 mm to 80 mm, and the number of flue gas ejector channels 11 is the same as the number of peripheral gas spray guns 1, and the flue gas ejector channels 11 are radially evenly distributed around the axis of the housing 5. The diameter of the diversion channel 12 is 40 mm to 60 mm, and the number of diversion channels 12 is the same as the number of peripheral gas spray guns 1, and the diversion channels 12 are radially evenly distributed around the axis of the housing 5. The diameter of the nozzle of the peripheral gas spray gun 1 is 3 mm to 10 mm. The nozzle inclination angle of the main gas gun 2 is 45° to 75°.

[0028] Air enters the housing 5 through the air inlet 7, and the air volume is controlled by the regulating valve 8. It mixes and burns with the primary gas at the main gas nozzle 2 to form the first combustion zone. The peripheral spray gun 1 injects gas coaxially from the flue gas injection channel 11. The gas is carried in by the injection and a portion of the return flue gas mixes with the gas. It enters the upper part of the burner through the flue gas injection channel 11 and the diversion channel 12, where it mixes and burns with the unburned air and flue gas in the first zone to form the second combustion zone.

[0029] This invention utilizes a specially designed internal structure to achieve fuel staging and flue gas recirculation, ensuring thorough mixing and combustion of air and fuel gas to achieve low NOx emissions. More specifically, this invention employs a specially designed injection method and refractory brick structure to control the mixing of fuel and air, thereby controlling the entire combustion process of the fuel gas. This enhances flame stability, controls flame height and NOx formation, and creates a multi-stage flame by staging air and fuel, reducing flame temperature and significantly decreasing nitrogen oxide emissions.

[0030] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0031] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in sequences other than those illustrated or described herein.

[0032] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A staged combustion gas ejector low-NOx burner for chemical industry, characterized in that, include: The outer gas spray gun (1), the main gas gun (2), the refractory brick (3), the flame stabilizer (4), the shell (5), the gas collecting pipe (6), the air inlet (7), and the regulating valve (8); The air inlet (7) is located on the side of the housing (5), and the regulating valve (8) is located on the air inlet (7); the main gas gun (2) is coaxially located inside the housing (5), the flame stabilizer (4) is coaxially located with the main gas gun (2), and the refractory brick (3) is coaxially located on the top flange plate of the housing (5). The peripheral gas spray gun (1) is mounted on the top flange plate of the housing (5). The outer edge of the refractory brick (3) is provided with a flue gas ejection channel (11) arranged coaxially with the peripheral gas spray gun (1). The bottom of the peripheral gas spray gun (1) is connected to the gas collecting pipe (6). The inner side of the refractory brick (3) is provided with a diversion channel (12) arranged parallel to the flue gas ejection channel (11). The diameter of the flue gas ejector channel (11) is 50mm to 80mm, and the number of the flue gas ejector channels (11) is the same as the number of the peripheral gas spray guns (1). The flue gas ejector channels (11) are radially evenly distributed around the axis of the housing (5). The diameter of the diversion channel (12) is 40mm to 60mm, and the number of the diversion channel (12) is the same as the number of the peripheral gas spray guns (1). The diversion channel (12) is radially evenly distributed around the axis of the housing (5).

2. The staged combustion gas ejector low-NOx burner for chemical industry as described in claim 1, characterized in that, The number of peripheral gas spray guns (1) is 6 to 18, and the peripheral gas spray guns (1) are radially evenly distributed around the axis of the housing (5).

3. The staged combustion gas ejector low-NOx burner for chemical industry as described in claim 1, characterized in that, The diameter of the nozzle of the peripheral gas spray gun (1) is 3mm to 10mm.

4. The staged combustion gas ejector low-NOx burner for chemical industry as described in claim 3, characterized in that, The nozzle angle of the main gas gun (2) is 45-75 degrees.

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