Premix burner for steel wire rope heat treatment furnace

Abstract

The application discloses a premixing burner for a steel wire rope heat treatment furnace, which comprises a gas pipe, an air pipe, a mixing chamber and a burner head, wherein the gas pipe and the air pipe are communicated with the mixing chamber respectively to respectively deliver gas and air to the mixing chamber; the mixing chamber is connected with the burner head to deliver mixed gas of the air and the gas to a furnace chamber; wherein the burner head is provided with a jet channel, the jet channel comprises a first swirl section, a connecting section and a second swirl section which are connected in sequence; wherein the first swirl section is communicated with the mixing chamber, the first swirl section is provided with first swirl vanes, and the cross-sectional diameter of the first swirl section gradually decreases along the jet direction; the second swirl section is communicated with the furnace chamber, the second swirl section is provided with second swirl vanes, and the cross-sectional diameter of the second swirl section gradually increases along the jet direction. The application can improve the uniformity of gas and air mixing, promote the complete combustion reaction, improve the combustion stability, and thus realize an efficient, low-pollution and high-stability combustion process.

Description

Technical Field

[0001] This application relates to the field of burner technology, and in particular to a premixed burner for wire rope heat treatment furnaces. Background Technology

[0002] Steel wire heat treatment furnaces typically employ counter-flow open-flame natural gas tunnel kilns. Each furnace houses multiple burners, with individual burner power ranging from 2kW to 8kW. The furnace temperature is between 900℃ and 1050℃, and the temperature difference between the furnace and the set temperature must be ≤±10℃. To prevent the steel wire from reacting with oxygen in the air, zoned atmosphere control is necessary within the furnace. For example, the furnace is divided into a heating section, a first soaking section, and a second soaking section from the steel wire inlet to the outlet. The heating section requires a CO content of 0-1%, the first soaking section requires 1%-2%, and the second soaking section requires 2%-3%. Since the flue gas outlet is located in the heating section, the heating section requires an equivalence ratio <1, while the soaking section requires an equivalence ratio ≥1. In related technologies, premixed gas burners mix air and fuel gas before injecting it into the furnace of the steel wire rope heat treatment furnace for combustion. When the steel wire heat treatment furnace is running, it is necessary to control the furnace temperature within a reasonable range and to control the atmosphere inside the furnace in different zones. Therefore, the burners in each zone of the furnace need to be started and stopped frequently, and the air-fuel ratio needs to be precisely controlled.

[0003] However, existing burners have poor combustion performance, requiring a significant increase in air supply to maintain a reducing atmosphere in the furnace. This leads to incomplete combustion of a large amount of fuel gas, resulting in severe carbon buildup at the furnace exhaust ports and CO levels exceeding 5% in the flue gas. Furthermore, existing burners do not achieve low-NOx combustion, and NO content in the flue gas is high. X The content is >100mg / Nm³. Summary of the Invention

[0004] This application aims to address at least one of the technical problems existing in the prior art. Therefore, the purpose of this application is to provide a premixed burner for wire rope heat treatment furnaces, aiming to solve the problems of unstable combustion, CO and NO emissions, etc., in the prior art. X The problem of high emissions.

[0005] This application discloses a premixed burner for a wire rope heat treatment furnace. The premixed burner includes a gas pipe, an air pipe, a mixing chamber, and a burner head. The gas pipe and air pipe are respectively connected to the mixing chamber to supply gas and air to the mixing chamber. The mixing chamber is connected to the burner head to supply a mixture of air and gas to the furnace. The burner head is provided with a jet channel, which includes a first swirl section, a connecting section, and a second swirl section connected in sequence. The first swirl section is connected to the mixing chamber and is provided with a first swirl blade. The cross-sectional diameter of the first swirl section gradually decreases along the jet direction. The second swirl section is connected to the furnace and is provided with a second swirl blade. The cross-sectional diameter of the second swirl section gradually increases along the jet direction.

[0006] According to the premixed burner for wire rope heat treatment furnaces of this application, by improving the uniformity of gas and air mixing, the combustion reaction is promoted to be more complete and efficient, and CO and NO emissions are reduced. X Emissions; through two-stage swirl, the risk of backfire in premixed combustion is avoided and combustion stability is improved, thereby achieving a highly efficient, low-pollution, and highly stable combustion process.

[0007] According to some embodiments of this application, the first swirl blade and the second swirl blade have the same swirl direction, and the swirl angle of the second swirl blade is greater than or equal to the swirl angle of the first swirl blade.

[0008] According to some embodiments of this application, a first swirl channel is formed between two adjacent first swirl blades, and a second swirl channel is formed between two adjacent second swirl blades; wherein, the flow velocity at the outlet end of the first swirl channel is greater than or equal to the flow velocity at the inlet end of the second swirl channel, and the flow velocity at the inlet end of the second swirl channel is greater than the tempering velocity.

[0009] According to some embodiments of this application, the number of first swirl blades is greater than or equal to the number of second swirl blades.

[0010] According to some embodiments of this application, a flow equalization plate is provided in the mixing chamber.

[0011] According to some embodiments of this application, the burner head is further provided with a mixing gas jet port, which connects the mixing chamber and the furnace and extends along the axial direction of the burner head; wherein, multiple mixing gas jet ports and multiple jet channels are alternately spaced along the circumferential direction.

[0012] According to some embodiments of this application, the cross-sectional area of ​​the mixed gas jet orifice is smaller than the cross-sectional area of ​​the jet channel.

[0013] According to some embodiments of this application, an air pipe is sleeved around the gas pipe to form an air passage between the air pipe and the gas pipe, and the air passage connects to the mixing chamber; a gas passage is formed inside the gas pipe, and the end of the gas pipe near the mixing chamber is closed, and a gas jet port is provided on the peripheral wall of the gas pipe, which connects the gas passage and the air passage.

[0014] According to some embodiments of this application, the premixed burner further includes a first electrode sleeve and a second electrode sleeve, which are respectively disposed through the gas pipe, the mixing chamber and the burner head, and the ends of the first electrode sleeve and the second electrode sleeve extend to the outer end of the burner head; wherein, the first electrode sleeve is provided with an ignition electrode and the second electrode sleeve is provided with an ion probe.

[0015] According to some embodiments of this application, the air duct is connected to the outlet of the ventilation fan, and the fan is used to draw flue gas from the furnace and deliver flue gas and air to the air duct.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a front view of the structure of a premixed burner according to some embodiments of this application; Figure 2 This is a left view of the structure of a premixed burner according to some embodiments of this application; Figure 3 This is a structural cross-sectional view of a premixed burner according to some embodiments of this application; Figure 4 This is a cross-sectional view of the mixing chamber and burner head according to some embodiments of this application; Figure 5 This is a schematic diagram of the end face structure of the burner head according to some embodiments of this application.

[0018] Figure label: Gas pipe 10; gas jet port 11; gas flange 12; air pipe 20; air flange 21; mixing chamber 30; flow equalization plate 40; burner head 50; jet channel 51; first swirl section 511; connecting section 512; second swirl section 513; first swirl blade 52; second swirl blade 53; mixed gas jet port 54; first electrode sleeve 60; second electrode sleeve 70. Detailed Implementation

[0019] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0020] The following is for reference. Figures 1-5 This application describes a premixed burner for a wire rope heat treatment furnace, according to an embodiment of the present application.

[0021] This application proposes a premixed burner for a wire rope heat treatment furnace. The premixed burner includes a gas pipe 10, an air pipe 20, a mixing chamber 30, and a burner head 50. The gas pipe 10 and the air pipe 20 are respectively connected to the mixing chamber 30 to supply gas and air to the mixing chamber 30. The mixing chamber 30 is connected to the burner head 50 to supply a mixture of air and gas to the furnace. The burner head 50 is provided with a jet channel 51, which includes a first swirl section 511, a connecting section 512, and a second swirl section 513 connected in sequence. The first swirl section 511 is connected to the mixing chamber 30 and is provided with a first swirl blade 52. The cross-sectional diameter of the first swirl section 511 gradually decreases along the jet direction. The second swirl section 513 is connected to the furnace and is provided with a second swirl blade 53. The cross-sectional diameter of the second swirl section 513 gradually increases along the jet direction.

[0022] The gas pipe 10 is used to supply gas into the mixing chamber 30, and the air pipe 20 is used to supply air into the mixing chamber 30. The air and gas are mixed in the mixing chamber 30, and then transported to the furnace via the burner head 50 for combustion. The burner head 50 is equipped with a jet channel 51, which connects the mixing chamber 30 and the furnace to facilitate the transmission of the mixed gas. Specifically, as shown... Figure 4 As shown, the jet channel 51 is divided into a first swirl section 511, a connecting section 512, and a second swirl section 513. The cross-sectional diameter of the first swirl section 511 gradually decreases along the jet direction. It contains first swirl blades 52, which can increase the swirl velocity through the tapered structure, thereby enhancing the mixing characteristics of air and fuel gas, improving the uniformity of mixing, promoting complete combustion, and reducing CO emissions. Simultaneously, uniform mixing of air and fuel gas helps improve the uniformity of the combustion flame distribution, reducing the high-temperature zone, and thus reducing NO emissions. XEmissions. The cross-sectional diameter of the second swirl section 513 gradually increases along the jet direction. It contains second swirl blades 53, which, through their gradually expanding structure, create a reasonable combustion flow field, thereby improving flame stability, combustion efficiency, and reducing pollutant emissions. The first swirl section 511 and the second swirl section 513 constitute a two-stage swirl, with a connecting section 512 between them. This provides development space for the first-stage swirl, further enhancing the uniform mixing effect. Simultaneously, the connecting section 512, in conjunction with the first swirl section 511 and the second swirl section 513, establishes a flashback acceleration flow field, effectively preventing flashback.

[0023] According to the premixed burner for wire rope heat treatment furnaces of this application, by improving the uniformity of gas and air mixing, the combustion reaction is promoted to be more complete, the uniformity of combustion flame distribution is improved, and CO and NO emissions are reduced. X Emissions; through two-stage swirl, the risk of backfire in premixed combustion is avoided and combustion stability is improved, thereby achieving a highly efficient, low-pollution, and highly stable combustion process.

[0024] Experimental testing has shown that the premixed burner described in this application can achieve the following: NO content in the furnace flue gas composition... X The content of CO is ≤50mg / Nm³, and the CO emission in the furnace tail gas is ≤50mg / Nm³.

[0025] In some embodiments, the connecting section 512 is a cylindrical section, and the outlet cross-sectional area of ​​the first swirl section 511 is the same as the inlet cross-sectional area of ​​the second swirl blade 53.

[0026] According to some embodiments of this application, the first swirl blade 52 and the second swirl blade 53 have the same swirl direction, and the swirl angle of the second swirl blade 53 is greater than or equal to the swirl angle of the first swirl blade 52. The increased swirl angle of the second swirl blade 53 compared to the first swirl blade 52 can increase the range of the central recirculation zone, thereby forming a stable combustion flame structure and further improving combustion stability and flame distribution uniformity.

[0027] According to some embodiments of this application, a first swirl channel is formed between two adjacent first swirl blades 52, and a second swirl channel is formed between two adjacent second swirl blades 53. The flow velocity at the outlet of the first swirl channel is greater than or equal to the flow velocity at the inlet of the second swirl channel, and the flow velocity at the inlet of the second swirl channel is greater than the flashback velocity. Since both the flow velocity at the outlet of the first swirl channel and the flow velocity at the inlet of the second swirl channel are greater than the flashback velocity, a flashback prevention effect can be achieved. Furthermore, the flow velocity at the outlet of the first swirl channel is greater than the flow velocity at the inlet of the second swirl channel, providing a double protection effect. Even when fluctuations in air or gas pressure cause a decrease in the flow velocity at the inlet of the second swirl channel, a flashback prevention effect can still be effectively achieved.

[0028] According to some embodiments of this application, the number of first swirl blades 52 is greater than or equal to the number of second swirl blades 53. Since the outlet cross-sectional area of ​​the first swirl section 511 is the same as the inlet cross-sectional area of ​​the second swirl section 513, when the number of first swirl blades 52 is greater than or equal to the number of second swirl blades 53, the increased cross-sectional area of ​​the swirl blades leads to a decrease in the flow area, thereby achieving an outlet velocity of the first swirl channel that is greater than or equal to the inlet velocity of the second swirl channel.

[0029] According to some embodiments of this application, a flow equalization plate 40 is provided inside the mixing chamber 30. For example, Figure 3 , 4 As shown, by setting the flow equalization plate 40, the mixed gas can be uniformly delivered to the burner 50. In some embodiments, the flow equalization plate 40 is constructed as a perforated plate, which utilizes the local drag effect and turbulence reorganization mechanism to achieve uniform flow field distribution.

[0030] According to some embodiments of this application, the burner head 50 is further provided with a mixing gas jet port 54, which connects the mixing chamber 30 and the furnace, and extends axially along the burner head 50; wherein, a plurality of mixing gas jet ports 54 and a plurality of jet channels 51 are alternately spaced circumferentially. For example, Figure 5 As shown, the axial jet from the mixed gas jet nozzle 54 can penetrate deep into the furnace, elongating the combustion zone axially, thereby resulting in a more uniform flame distribution and more complete combustion within the furnace. Furthermore, the alternating circumferential arrangement of multiple mixed gas jet nozzles 54 and multiple jet channels 51 can combine the swirling and jetting effects to disperse the flame, prevent excessive flame concentration, and achieve a more uniform temperature distribution within the furnace, thus promoting complete combustion within the furnace.

[0031] In some embodiments, such as Figure 5 As shown, a plurality of mixed gas jet ports 54 are arranged radially between two adjacent jet channels 51; specifically, the number of mixed gas jet ports 54 located between two adjacent jet channels 51 can be set to 1 to 3, and the specific number can be determined according to the specifications of the premixed burner.

[0032] According to some embodiments of this application, the cross-sectional area of ​​the mixed gas jet port 54 is smaller than the cross-sectional area of ​​the jet channel 51. For example, Figure 5 As shown, the cross-sectional area of ​​the gas-mixing jet orifice 54 is relatively small, which can increase the jet velocity and thus ensure flame length and penetration. The cross-sectional area of ​​the jet channel 51 is relatively large, which can generate a stable recirculation zone. The cross-sectional area of ​​the gas-mixing jet orifice 54 is smaller than that of the jet channel 51, which can prevent axial jet from disrupting the recirculation zone. The specific sizes of the cross-sectional areas of the gas-mixing jet orifice 54 and the jet channel 51 can be flexibly determined according to combustion requirements to jointly achieve high-stability, low-emission combustion.

[0033] According to some embodiments of this application, an air pipe 20 is sleeved around the gas pipe 10 to form an air passage between the air pipe 20 and the gas pipe 10, the air passage connecting to the mixing chamber 30; a gas passage is formed inside the gas pipe 10, and the end of the gas pipe 10 near the mixing chamber 30 is closed, and a gas jet port 11 is provided on the peripheral wall of the gas pipe 10, the gas jet port 11 connecting the gas passage and the air passage. Wherein, as Figure 3 As shown, the gas passage is located at the center of the burner, and the air passage is located on the outer periphery of the gas passage. Gas from the gas pipe 10 enters the air passage through a gas jet port 11 located on the peripheral wall, and flows into the mixing chamber 30 together with air. By providing the gas jet port 11 on the peripheral wall of the gas pipe 10, the gas jet can form a radial jet, causing disturbance and turbulent mixing of the air in the air passage, thereby promoting the premixing uniformity of air and gas in the mixing chamber 30, which is beneficial for complete combustion.

[0034] In some embodiments, the gas pipe 10 is provided with a plurality of gas jet ports 11, which are evenly spaced circumferentially on the peripheral wall of the gas pipe 10 near the mixing chamber 30.

[0035] In some embodiments, such as Figure 3 As shown, one end of the air pipe 20 is connected to the peripheral wall of the mixing chamber 30, and the other end of the air pipe 20 is sealed to the outer wall of the gas pipe 10. Figure 1-3 As shown, the end of the air pipe 20 away from the mixing chamber 30 is connected to an air flange 21 for connection to an air supply unit; the air flange 21 is connected to the periphery of the air pipe 20 via a pipe.

[0036] In some embodiments, such as Figure 1 , 2 As shown, the end of the gas pipe 10 away from the mixing chamber 30 is connected to the gas flange 12 for connection to the gas supply unit; the gas flange 12 is connected to the periphery of the gas pipe 10 through a pipeline.

[0037] According to some embodiments of this application, the premixed burner further includes a first electrode sleeve 60 and a second electrode sleeve 70. The first electrode sleeve 60 and the second electrode sleeve 70 are respectively disposed through the gas pipe 10, the mixing chamber 30, and the burner head 50, and their ends extend to the outer end of the burner head 50. The first electrode sleeve 60 is provided with an ignition electrode, and the second electrode sleeve 70 is provided with an ion probe. Ignition is achieved by assembling the ignition electrode using the first electrode sleeve 60; flame detection is achieved by assembling the ion probe using the second electrode sleeve 70. Figure 2 , 3 As shown, one end of the first electrode sleeve 60 and the second electrode sleeve 70 extend to the outer end of the gas pipe 10, respectively; Figure 3, 5 As shown, the other ends of the first electrode sleeve 60 and the second electrode sleeve 70 extend to the outer end of the burner head 50, respectively.

[0038] According to some embodiments of this application, the air duct 20 is connected to a fan outlet. The fan is used to extract flue gas from the furnace and deliver flue gas and air to the air duct 20. The fan can be part of an air supply unit, used to extract flue gas from the furnace, mix the flue gas with air, and then deliver it to the air duct 20. The air duct 20 delivers flue gas and air to the mixing chamber 30, which can reduce the oxygen content in the mixture of fuel gas and air, thereby diluting the flame, preventing the formation of a high-temperature zone, and promoting complete combustion of the fuel gas, thus reducing NO. X Emissions. Based on the stable combustion effect of the premixed burner structure of this application, this embodiment can achieve ultra-low nitrogen combustion by utilizing flue gas external recirculation technology, further reducing pollutant emissions.

[0039] Through experimental testing, combined with flue gas external recirculation technology, the premixed burner of this application can achieve the reduction of NO in flue gas composition. X <30mg / Nm³.

[0040] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application 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 this application.

[0041] In the description of this application, "first feature" and "second feature" may include one or more of the features.

[0042] In the description of this application, "multiple" means two or more.

[0043] In the description of this application, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or it may include the first and second features not being in direct contact but being in contact through another feature between them.

[0044] In the description of this application, the terms "above," "over," and "on top" for the first feature and the second feature include the first feature being directly above or diagonally above the second feature, or simply indicate that the first feature is at a higher horizontal level than the second feature.

[0045] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0046] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A premixed burner for a wire rope heat treatment furnace, characterized in that, It includes a gas pipe, an air pipe, a mixing chamber, and a burner head, wherein the gas pipe and the air pipe are respectively connected to the mixing chamber to supply gas and air to the mixing chamber; the mixing chamber is connected to the burner head to supply the mixture of air and gas to the furnace; wherein, The burner head is provided with a jet channel, which includes a first swirl section, a connecting section, and a second swirl section connected in sequence; wherein, the first swirl section is connected to the mixing chamber, the first swirl section is provided with a first swirl blade, and the cross-sectional diameter of the first swirl section gradually decreases along the jet direction; the second swirl section is connected to the furnace, the second swirl section is provided with a second swirl blade, and the cross-sectional diameter of the second swirl section gradually increases along the jet direction.

2. The premixed burner for a wire rope heat treatment furnace according to claim 1, characterized in that, The first swirl blade and the second swirl blade have the same swirl direction, and the swirl angle of the second swirl blade is greater than or equal to the swirl angle of the first swirl blade.

3. The premixed burner for a wire rope heat treatment furnace according to claim 1, characterized in that, A first swirl channel is formed between two adjacent first swirl blades, and a second swirl channel is formed between two adjacent second swirl blades; wherein, the flow velocity at the outlet end of the first swirl channel is greater than or equal to the flow velocity at the inlet end of the second swirl channel, and the flow velocity at the inlet end of the second swirl channel is greater than the tempering velocity.

4. The premixed burner for a wire rope heat treatment furnace according to claim 3, characterized in that, The number of the first swirl blades is greater than or equal to the number of the second swirl blades.

5. The premixed burner for a wire rope heat treatment furnace according to claim 1, characterized in that, The mixing chamber is equipped with a flow equalization plate.

6. The premixed burner for a wire rope heat treatment furnace according to claim 1, characterized in that, The burner head is also provided with a mixing gas jet port, which connects the mixing chamber and the furnace and extends along the axial direction of the burner head; wherein, a plurality of the mixing gas jet ports and a plurality of the jet channels are alternately spaced along the circumference.

7. The premixed burner for a wire rope heat treatment furnace according to claim 6, characterized in that, The cross-sectional area of ​​the mixed gas jet orifice is smaller than the cross-sectional area of ​​the jet channel.

8. The premixed burner for a wire rope heat treatment furnace according to claim 1, characterized in that, The air pipe is sleeved around the outer periphery of the gas pipe to form an air passage between the air pipe and the gas pipe, and the air passage connects to the mixing chamber; A gas passage is formed inside the gas pipe, and the end of the gas pipe near the mixing chamber is closed. A gas jet port is provided on the peripheral wall of the gas pipe, and the gas jet port connects the gas passage and the air passage.

9. The premixed burner for a wire rope heat treatment furnace according to claim 8, characterized in that, Also includes: A first electrode sleeve and a second electrode sleeve are respectively disposed through the gas pipe, the mixing chamber, and the burner head, and the ends of the first electrode sleeve and the second electrode sleeve extend to the outer end of the burner head; wherein... The first electrode sleeve is equipped with an ignition electrode, and the second electrode sleeve is equipped with an ion probe.

10. The premixed burner for a wire rope heat treatment furnace according to claim 1, characterized in that, The air duct is connected to the outlet of the ventilation fan, and the fan is used to draw out the flue gas in the furnace and deliver the flue gas and air to the air duct.

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