Environment-friendly high-temperature-resistant kiln furniture with reduced nitride emission and preparation method thereof

Abstract

This invention relates to the field of kiln furniture, and more particularly to an environmentally friendly high-temperature resistant kiln furniture for reducing nitrogen oxide emissions and its preparation method. To address the technical problems of burners struggling to achieve high combustion efficiency and the significant increase in the proportion of incompletely burned nitrogen oxides when reducing the amount of flame released by the burner, this invention provides an environmentally friendly high-temperature resistant kiln furniture for reducing nitrogen oxide emissions, comprising auxiliary burners and gas collecting pipes; each auxiliary burner has a gas collecting pipe fixedly connected to its central portion. The main burner of this invention introduces combustion-supporting gas into the gas collecting pipes, and the unburned nitrogen-containing gas from the main burner is collected into the gas collecting pipes by the exhaust gas guide plate inside the kiln top. The mixed gas is then introduced into the auxiliary burner, where it undergoes combustion together with the combustion gas, enabling the unburned nitrogen-containing gas to be burned again within the auxiliary burner, thereby improving the combustion efficiency of the nitrogen-containing gas.

Description

Technical Field

[0001] This invention relates to the field of kiln furniture, and more particularly to an environmentally friendly high-temperature resistant kiln furniture that reduces nitrogen oxide emissions and its preparation method. Background Technology

[0002] Modern kiln furniture is typically assembled from highly integrated mechanized devices. The assembled kiln furniture is divided into preheating kiln furniture, flue gas exhaust equipment, firing kiln furniture, and cooling kiln furniture. The blanks to be prepared are transported sequentially through each kiln furniture by conveyor rollers to complete the corresponding processing work, thus achieving efficient batch processing.

[0003] In kiln operation, incomplete combustion of nitrides produced in the burner poses a significant pollution hazard to the atmospheric environment. To address the issue of incomplete combustion of nitrides emitted by the burner, patent CN212746452U discloses a low-NOx flat flame burner that changes the problems caused by conventional combustion methods, greatly improving the combustion efficiency of nitrides. However, this burner is located at the top of the kiln furniture. When working in conjunction with burners on both sides of the kiln furniture for heating, the nitrides emitted by the burners on both sides of the kiln furniture still do not have high combustion efficiency. Furthermore, when the kiln furniture temperature is changed, the amount of flame released by the burner needs to be reduced, which will lead to a significant increase in the proportion of incompletely burned nitrides. Summary of the Invention

[0004] To overcome the shortcomings of burners located at the top of the kiln furniture being difficult to coordinate with burners on both sides of the kiln furniture for efficient combustion, and the significant increase in the proportion of incomplete combustion of nitrogen oxides when the amount of flame released by the burners is reduced, this invention provides an environmentally friendly high-temperature resistant kiln furniture with reduced nitrogen oxide emissions and its preparation method.

[0005] The technical solution is as follows: An environmentally friendly high-temperature resistant kiln furniture for reducing nitrogen oxide emissions, comprising a kiln bottom, side walls, conveyor rollers, main burners, main gas pipes, auxiliary gas pipes, a kiln top, auxiliary burners, gas collecting pipes, auxiliary gas pipes, and exhaust gas guide plates; the kiln bottom and the side walls on both sides, together with the kiln top, form the combustion chamber of the kiln furniture; several conveyor rollers are connected between the middle of the two side walls; several main burners are installed on the inner upper walls of each of the two side walls; a main gas pipe is fixedly connected to the middle of each of the two side walls through several first fixed seats; each main burner is connected to the main gas pipe through a second conduit; an auxiliary gas pipe is fixedly connected to the upper and lower sides of each of the two side walls through several second fixed seats. Each main burner is connected to a combustion-supporting gas pipe via a third conduit; several auxiliary burners are installed in the middle of the kiln roof; each auxiliary burner has a gas collecting pipe fixed to its middle; auxiliary gas pipes are fixed to the upper side of the kiln roof via several third fixed seats; each auxiliary burner has an auxiliary gas collecting pipe connected to its upper end; each main burner located above the conveyor rollers guides the combustion-supporting gas from the combustion-supporting gas pipe into a corresponding gas collecting pipe, and the unburned nitrogen-containing gas from the main burners is collected into the gas collecting pipe by the exhaust gas guide plate inside the kiln roof. The unburned nitrogen-containing gas is then thoroughly mixed with the combustion-supporting gas by the mixing components located between the gas collecting pipe and the auxiliary burners and introduced into the auxiliary burners for re-combustion by the mixing components located between the gas collecting pipes and the auxiliary burners.

[0006] Furthermore, each main burner is equipped with an internal gas pipe, and each internal gas pipe has a main burner fixed to its outer end; the internal gas pipe of each main burner is connected to the main gas pipe through a second conduit.

[0007] Furthermore, each main burner located above the conveyor roller is connected to a first conduit on its upper side; each first conduit is fixed to the inner surface of an exhaust gas guide plate; and the upper end of each first conduit is connected to a corresponding gas collection pipe.

[0008] Furthermore, each auxiliary burner has an auxiliary burner connected to its lower end.

[0009] Furthermore, several inclined air trough structures are provided on the upper side of the outer end of each main burner located above the conveyor roller, and each inclined air trough structure is configured to be inclined upward toward the exhaust gas guide plate.

[0010] Furthermore, each gas collecting pipe has a main flame head fixed to its lower side; each main flame head is designed as a triangular structure that is narrow on the front and rear sides and wide on the left and right sides.

[0011] Furthermore, each exhaust gas guide plate has a first baffle fixedly attached to its lower side near the end of the gas collection pipe, and each first baffle has a ventilation groove structure in the middle.

[0012] Furthermore, the mixing assembly includes a small motor, a rotating shaft, a first spur gear, a second spur gear, a sleeve, an upper annular fan wheel, an internal gear ring, a lower annular fan wheel, and an external gear ring; a small motor is fixedly connected to the upper side of each gas collecting pipe; a rotating shaft is rotatably connected to the left side of each gas collecting pipe; a rotating shaft is fixedly connected to the output shaft of each small motor; a first spur gear is fixedly connected to the lower side of each rotating shaft; a second spur gear is fixedly connected to the lower end of each rotating shaft; a sleeve is fixedly connected to the outer surface of each auxiliary burner; an upper annular fan wheel is rotatably connected between each sleeve and the gas collecting pipe; an internal gear ring is fixedly connected to the lower side of each upper annular fan wheel; each first spur gear meshes with an internal gear ring; a lower annular fan wheel is rotatably connected to the lower inner side of each gas collecting pipe; an external gear ring is fixedly connected to the upper side of each lower annular fan wheel; and each second spur gear meshes with an external gear ring.

[0013] Furthermore, it also includes a range control component and a secondary flame collector; each gas collecting pipe has a secondary flame collector slidably connected to its outer surface; the exhaust gas guide plate is provided with a range control component, which includes an electric push rod, a slide rail, a second baffle, a third baffle, a first bushing, a second bushing, and a pull rod; each exhaust gas guide plate on the left side has an electric push rod fixedly connected to it; each electric push rod's telescopic end has a secondary flame collector fixedly connected to it; each exhaust gas guide plate has a slide rail fixedly connected to its front and rear lower sides; each pair of front and rear slide rails has a second baffle fixedly connected between the ends of the front and rear slide rails closest to the gas collecting pipe; each pair of front and rear slide rails has a third baffle slidably connected between the ends of the front and rear slide rails furthest from the gas collecting pipe; each third baffle has a first bushing rotatably connected to its lower side via a rotating shaft; each secondary flame collector has a second bushing rotatably connected to its left and right sides via a rotating shaft; each first bushing is fixedly connected to an adjacent second bushing with a pull rod.

[0014] A method for preparing an environmentally friendly high-temperature resistant kiln furniture that reduces nitrogen oxide emissions includes the following steps:

[0015] S1: Billet conveying, the billet is conveyed sequentially through the preheating kiln furniture, flue gas equipment, firing kiln furniture and cooling kiln furniture of the kiln furniture group by the conveying equipment;

[0016] S2: Heating and firing, gas and auxiliary gas are introduced into the main burner and auxiliary burner and ignited, so that the main burner and auxiliary burner spray flames to uniformly heat and fire the billet on the conveying equipment.

[0017] S3: Exhaust gas collection, which collects the unburned nitrogen oxide gas discharged from the main burner into the auxiliary burner and mixes it with the fuel gas and auxiliary fuel gas;

[0018] S4: Exhaust gas re-combustion, which re-combusts the mixed unburned nitrogen oxide gas, fuel gas and combustion-supporting gas in the auxiliary burner, improving the combustion efficiency of nitrogen-containing gas and reducing the emission of harmful nitrogen oxides.

[0019] The beneficial effects of this invention are as follows: In the technical solution provided by this invention, the main burners located on both sides of the kiln furniture are connected to the gas collecting pipes located on the auxiliary burners at the top of the kiln furniture. During combustion, each main burner above the conveyor roller directs the combustion-supporting gas from its combustion-supporting pipe into a corresponding gas collecting pipe. Unburned nitrogen-containing gas from the main burners is collected into the gas collecting pipes by the exhaust gas guide plates inside the kiln top. The collected unburned nitrogen-containing gas is then thoroughly mixed with the combustion-supporting gas by mixing components located between the gas collecting pipes and the auxiliary burners, and the mixed gas is then introduced into the auxiliary burners. It works in conjunction with the combustion gases in the auxiliary burner to achieve secondary combustion of unburned nitrogen-containing gases, thereby improving the combustion efficiency of nitrogen-containing gases and reducing the emission of harmful nitrogen oxides. Even if it is necessary to reduce the temperature of the kiln furniture and reduce the flame volume of each burner, the unburned nitrogen-containing gases can still be effectively collected into the gas collection pipe for secondary combustion. This solves the technical problems that the burner located at the top of the kiln furniture is difficult to cooperate with the burners on both sides of the kiln furniture to achieve high combustion efficiency, and that reducing the flame volume released by the burner will lead to a significant increase in the proportion of incomplete combustion of nitrogen oxides. Attached Figure Description

[0020] Figure 1 This is a three-dimensional structural diagram of the present application;

[0021] Figure 2 This is a partial three-dimensional structural schematic diagram of this application;

[0022] Figure 3 This is a schematic diagram of the three-dimensional structure of the kiln roof in this application;

[0023] Figure 4 This is a three-dimensional structural diagram of the main burner of this application;

[0024] Figure 5 This is a cross-sectional view of the gas collecting pipe in this application;

[0025] Figure 6 This is a schematic diagram of a first partial three-dimensional structure of the hybrid component of this application;

[0026] Figure 7 This is a schematic diagram of a second partial three-dimensional structure of the hybrid component of this application;

[0027] Figure 8 This is a schematic diagram of the first three-dimensional structure of the range control component of this application;

[0028] Figure 9 This is a schematic diagram of the second three-dimensional structure of the range control component of this application;

[0029] Figure 10 This is a three-dimensional structural diagram of the exhaust gas guide plate of this application;

[0030] Figure 11 This is a schematic diagram of the low NOx emission control system in the tunnel kiln of this application.

[0031] In the attached diagrams: 1-Kiln bottom, 2-Side wall, 21-First fixed seat, 22-Second fixed seat, 3-Transfer roller, 4-Main burner, 41-Internal gas pipe, 42-Main burner, 43-First duct, 44-Inclined air chute, 5-Main gas pipe, 51-Second duct, 6-Auxiliary gas pipe, 61-Third duct, 7-Kiln top, 71-Third fixed seat, 8-Auxiliary burner, 81-Auxiliary burner, 9-Gas collecting pipe, 91-Main flame collector, 92-Auxiliary flame collector, 10-Auxiliary... Gas pipe, 11-exhaust gas guide plate, 111-first baffle, 101-small motor, 102-rotating shaft, 103-first spur gear, 104-second spur gear, 105-pipe sleeve, 106-upper annular fan wheel, 107-internal gear ring, 108-lower annular fan wheel, 109-external gear ring, 201-electric push rod, 202-slide rail, 203-second baffle, 204-third baffle, 205-first bushing, 206-second bushing, 207-pull rod. Detailed Implementation

[0032] The invention will now be described more fully below with reference to the accompanying drawings, in which presently preferred embodiments of the invention are illustrated. However, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness and to fully convey the scope of the invention to those skilled in the art.

[0033] A method for preparing an environmentally friendly high-temperature resistant kiln furniture that reduces nitrogen oxide emissions includes the following steps:

[0034] S1: Billet conveying, the billet is conveyed sequentially through the preheating kiln furniture, flue gas equipment, firing kiln furniture and cooling kiln furniture of the kiln furniture group by the conveying equipment;

[0035] S2: Heating and firing, gas and auxiliary gas are introduced into the main burner 4 and the auxiliary burner 8 and ignited, so that the main burner 4 and the auxiliary burner 8 spray flames to uniformly heat and fire the billet on the conveying equipment.

[0036] S3: Exhaust gas collection, which collects the unburned nitrogen oxide gas discharged from the main burner 4 into the auxiliary burner 8 and mixes it with the fuel gas and auxiliary fuel gas;

[0037] S4: Exhaust gas re-combustion, which re-combusts the mixed unburned nitrogen oxide gas, fuel gas and combustion-supporting gas in the auxiliary burner 8, improving the combustion efficiency of nitrogen-containing gas and reducing the emission of harmful nitrogen oxides.

[0038] Example 1

[0039] An environmentally friendly, high-temperature resistant kiln furniture that reduces nitrogen oxide emissions, such as... Figures 1-7 and Figure 10 As shown, the kiln includes a mixing assembly, a kiln bottom 1, side walls 2, conveyor rollers 3, a main burner 4, a main gas pipe 5, an auxiliary gas pipe 6, a kiln top 7, an auxiliary burner 8, a gas collecting pipe 9, an auxiliary gas pipe 10, and a waste gas guide plate 11. A side wall 2 is fixedly connected to the left and right sides of the kiln bottom 1 by fasteners. The kiln top 7 is fixedly connected between the upper sides of the two side walls 2 by fasteners. Several conveyor rollers 3 are connected between the middle sections of the two side walls 2. Several main burners 4 are installed on the inner upper walls of each of the two side walls 2. A main gas pipe 5 is bolted to the middle section of each of the two side walls 2 by several first fixing seats 21. Each main burner 4 is connected to the main gas pipe 5 through a second conduit 51. The upper and lower sides of the two side walls 2 are respectively connected by... Several second fixed seats 22 are each bolted to a combustion-supporting pipe 6; each main burner 4 is connected to the combustion-supporting pipe 6 through a third conduit 61; several auxiliary burners 8 are installed in the middle of the kiln top 7; each auxiliary burner 8 is fixedly connected to a gas collecting pipe 9 in the middle; the upper side of the kiln top 7 is bolted to an auxiliary gas collecting pipe 10 through several third fixed seats 71; the upper end of each auxiliary burner 8 is connected to an auxiliary gas collecting pipe 10; several exhaust gas guide plates 11 are symmetrically fixed to the inner left and inner right sides of the kiln top 7; each exhaust gas guide plate 11 is connected to a gas collecting pipe 9; a mixing component is connected inside the gas collecting pipe 9; each auxiliary burner 8 is connected to a mixing component; each main burner 4 located above the conveyor roller 3 is connected to a corresponding gas collecting pipe 9.

[0040] like Figure 4 As shown, each main burner 4 has an internal gas pipe 41 inside, and a main burner 42 is fixedly connected to the outer end of each internal gas pipe 41; each internal gas pipe 41 of the main burner 4 is connected to the main gas pipe 5 through a second conduit 51.

[0041] like Figures 3-5 As shown, each main burner 4 located above the conveyor roller 3 is connected to a first conduit 43 on its upper side; each first conduit 43 is fixed to the inner surface of an exhaust gas guide plate 11; the upper end of each first conduit 43 is connected to a corresponding gas collecting pipe 9; each main burner 4 located above the conveyor roller 3 has several inclined air troughs 44 on its upper side at its outer end, and each inclined air trough 44 is configured to be inclined upward toward the exhaust gas guide plate 11.

[0042] like Figure 5As shown, each auxiliary burner 8 has an auxiliary burner 81 connected to its lower end.

[0043] like Figure 5 As shown, each gas collecting pipe 9 has a main flame head 91 fixed to its lower side; each main flame head 91 is configured as a triangular structure that is narrow on the front and rear sides and wide on the left and right sides.

[0044] like Figure 2 and Figure 10 As shown, each exhaust gas guide plate 11 is configured as an arc-shaped structure that is close to the inner surface of the kiln top 7; a first baffle 111 is fixedly connected to the lower side of each exhaust gas guide plate 11 near the end of the gas collecting pipe 9, and a ventilation groove structure is provided in the middle of each first baffle 111.

[0045] like Figure 5-7 As shown, the mixing assembly includes a small motor 101, a rotating shaft 102, a first spur gear 103, a second spur gear 104, a sleeve 105, an upper annular fan wheel 106, an internal gear ring 107, a lower annular fan wheel 108, and an external gear ring 109; each air collecting pipe 9 is bolted to the upper side of a small motor 101; each air collecting pipe 9 is rotatably connected to the left side of a rotating shaft 102; the output shaft of each small motor 101 is fixedly connected to a rotating shaft 102; each rotating shaft 102 is fixedly connected to the lower side of a first spur gear 103; and each rotating shaft 102 is fixedly connected to the lower end of a... There is a second spur gear 104; a sleeve 105 is fixedly connected to the outer surface of each auxiliary burner 8; an upper annular fan wheel 106 is rotatably connected between each sleeve 105 and the gas collecting pipe 9; an internal gear ring 107 is welded to the lower side of each upper annular fan wheel 106; each first spur gear 103 meshes with an internal gear ring 107; a lower annular fan wheel 108 is rotatably connected to the lower inner side of each gas collecting pipe 9; an external gear ring 109 is welded to the upper side of each lower annular fan wheel 108; each second spur gear 104 meshes with an external gear ring 109.

[0046] This environmentally friendly, high-temperature resistant kiln furniture that reduces nitrogen oxide emissions is the firing kiln furniture in an assembled kiln furniture group. This environmentally friendly, high-temperature resistant kiln furniture that reduces nitrogen oxide emissions, together with the external preheating kiln furniture, flue gas equipment, and cooling kiln furniture, forms a complete kiln furniture group. Hereinafter, this environmentally friendly, high-temperature resistant kiln furniture that reduces nitrogen oxide emissions will be referred to as kiln furniture. The combustion chamber of this kiln furniture is composed of the kiln bottom 1, the side walls 2 on both sides, and the kiln top 7 located at the top.

[0047] The external preheating kiln furniture transports the preheated billets to the conveyor rollers 3 of this kiln furniture. The conveyor rollers 3 transport the billets forward, passing through each main burner 4 and auxiliary burner 8 in sequence. At the same time, the main gas pipe 5 transports gas through the second conduit 51 to the internal gas pipes 41 of each main burner 4, and sprays it outward from the internal gas pipes 41 and main burners 42 of the main burner 4. Meanwhile, the auxiliary gas pipe 6 transports auxiliary gas through the third conduit 61 to the outside of the internal gas pipes 41 of each main burner 4. When the auxiliary gas mixes with the internal gas pipes 41 after passing through the main burners 42, the ignition device built into the main burners 42 ignites the mixed gas and auxiliary gas, causing each main burner 4 to spray flames outward from the main burners 42. The flames sprayed by the main burners 4 heat and fire the billets on both sides of the conveyor rollers 3.

[0048] Part of the combustion gas flowing through the main burner 4 enters the gas collecting pipe 9 along the first conduit 43. Simultaneously, the main burner 42 ejects flames carrying a large amount of incompletely burned nitrogen oxide gas. This incompletely burned nitrogen oxide gas is captured by the exhaust gas guide plate 11 as it rises and moves backward. At the same time, the output shaft of the small motor 101 drives the rotating shaft 102 to rotate. The rotation of the rotating shaft 102 simultaneously drives the first spur gear 103 and the second spur gear 104 to rotate. The first spur gear 103 meshes with the internal gear ring 107, causing the upper annular fan wheel 106 to rotate forward. This causes the rotating upper annular fan wheel 106 to draw the incompletely burned nitrogen oxide gas captured by the exhaust gas guide plate 11 into the gas collecting pipe 9. Simultaneously, the second spur gear 104 meshes with the external gear ring 109, causing the lower annular fan wheel 108 to rotate in the opposite direction. This causes the rotating lower annular fan wheel 108 to draw the incompletely burned nitrogen oxide gas into the gas collecting pipe 9. The gas mixes with the combustion-supporting gas discharged from the first conduit 43 into the gas collecting pipe 9, and the mixed unburned nitrogen gas and combustion-supporting gas are transported to the auxiliary burner 81 by the lower annular fan wheel 108. At the same time, the auxiliary gas pipe 10 transports the gas to the auxiliary burner 81 of the auxiliary burner 8. The ignition device built into the auxiliary burner 81 ignites the nitrogen gas, combustion-supporting gas and gas in the auxiliary burner 81, so that the auxiliary burner 8 sprays flames downward through the auxiliary burner 81. At the same time, the flames sprayed downward from the auxiliary burner 81 split to both sides along the main flame head 91 and wrap upward around the edge of the main flame head 91. This realizes that the auxiliary burner 8 heats and fires the blank in the middle of the conveying roller 3 through the auxiliary burner 8 and the unburned nitrogen gas sprayed from the main burner 42 is burned again in the auxiliary burner 8, which improves the combustion efficiency of nitrogen-containing gas and reduces the emission of harmful nitrogen compounds.

[0049] In this way, even if it is necessary to reduce the temperature of the kiln furniture and reduce the flame volume of each main burner 4 and auxiliary burner 8, the unburned nitrogen-containing gas can still be effectively collected into the gas collection pipe 9 for re-combustion.

[0050] Example 2

[0051] like Figures 1-10 As shown, this embodiment is a further optimization based on the embodiment, and also includes a range control component and a secondary flame collector 92; each gas collecting pipe 9 has a secondary flame collector 92 slidably connected to its outer surface; the inner bottom of the secondary flame collector 92 has a groove that fits against the outer surface of the main flame collector 91; the exhaust gas guide plate 11 is provided with a range control component, which includes an electric push rod 201, a slide rail 202, a second baffle 203, a third baffle 204, a first bushing 205, a second bushing 206, and a pull rod 207; each exhaust gas guide plate 11 on the left side is fixedly connected to an electric push rod 201; the telescopic end of each electric push rod 201 is fixedly connected to... A secondary flame collector 92; a slide rail 202 is fixedly connected to the front and rear of the lower side of each exhaust gas guide plate 11; a second baffle 203 is welded between the ends of every two front and rear slide rails 202 near the gas collecting pipe 9; a third baffle 204 is slidably connected between the ends of every two front and rear slide rails 202 away from the gas collecting pipe 9; a first bushing 205 is rotatably connected to the lower side of each third baffle 204 via a rotating shaft; a second bushing 206 is rotatably connected to the left and right sides of each secondary flame collector 92 via a rotating shaft; a pull rod 207 is fixedly connected between each first bushing 205 and an adjacent second bushing 206.

[0052] During the heating and firing process of the blanks on both sides of the conveyor roller 3, the main burner 4 sprays flames outward through the main burner 42. Some of the unburned nitride gas sprayed from the main burner 42 enters the exhaust gas guide plate 11 through the ventilation groove of the first baffle 111. At the same time, the second baffle 203 and the third baffle 204 block the combustion gas sprayed upward from around the main flame head 91, preventing the sprayed completely burned gas from entering the gas collection pipe 9 through the ventilation groove of the first baffle 111. This effectively isolates the completely burned gas from entering the gas collection pipe 9, preventing the phenomenon that the flame heat sprayed downward by the auxiliary burner 8 through the auxiliary burner 81 is insufficient.

[0053] When it is necessary to significantly reduce the temperature of the kiln furniture and decrease the flame volume of each main burner 4 and auxiliary burner 8, the telescopic rod of the electric push rod 201 pushes the auxiliary flame head 92 downward, so that the auxiliary flame head 92 is fitted onto the outer surface of the main flame head 91. This allows the main burner 4 to shorten its flame length while the auxiliary flame head 92 expands the flame spray range of the auxiliary burner 8, ensuring that the billets in each area on the conveyor roller 3 can be effectively heated and fired. Simultaneously, the downward movement of the auxiliary flame head 92 drives the third baffle 204 via the pull rod 207. Moving along the slide rail 202 towards the gas collection pipe 9 reduces the amount of air passage blocked by the first baffle 111. As the flame volume of the main burner 4 and the auxiliary burner 8 is reduced, the proportion of incompletely burned nitrogen oxide gas in the exhaust gases of the main burner 4 and the auxiliary burner 8 is relatively high. This ensures that the incompletely burned nitrogen oxide gas exhausted by the main burner 4 and the auxiliary burner 8 is effectively captured by the exhaust gas guide plate 11 and enters the auxiliary burner 8 for re-combustion, thereby improving the combustion efficiency of nitrogen-containing gases and reducing the emission of harmful nitrogen oxides.

[0054] Example 3:

[0055] The principle of the low NOx emission control system in a tunnel kiln is as follows: The tunnel kiln consists of a kiln top wall and two outer kiln side walls. An insulated inner kiln wall is arranged inside the outer kiln wall, and fuel injectors are arranged on the side walls according to load requirements. Inside the tunnel kiln, kiln cars are arranged, moving within the kiln via slide rails installed inside. Kiln furniture is arranged on the kiln car platform, and material is placed in the material loading space; this process is repeated until the height of the kiln furniture on the kiln car reaches the maximum allowable value for the tunnel kiln. The kiln car system is installed throughout the entire tunnel kiln, including the kiln head, preheating section, firing section, cooling section, and kiln tail. Flue gas baffles are arranged on the kiln top of the firing section to increase the flue gas residence time.

[0056] During normal operation, the kiln furniture and kiln cars loaded with materials move at a certain speed from the kiln head to the kiln tail. The flue gas generated by combustion flows from the firing section towards the kiln head, directly contacting and flowing over the kiln furniture and materials. The direction of flue gas flow is opposite to the direction of kiln car movement. The firing section is the main area for the generation of nitrogen oxides in the tunnel kiln. When the kiln furniture passes through the preheating section, it can be slowly heated to above 800°C, directly contacting the high-temperature flue gas carrying a large amount of nitrogen oxides flowing from the firing section. At the same time, it contacts the inner surface of the kiln body and the baffles. The oxide material coated on the surface of the kiln furniture and the kiln body uses the oxygen vacancies formed on the surface at high temperature to adsorb NO in the flue gas. Under the action of oxygen vacancies, the NO bonds break rapidly, and the NO in the flue gas is directly decomposed into N2 and O2 and released, thereby achieving the direct degradation of nitrogen oxides in the high-temperature zone and reducing the NOx concentration in the flue gas.

[0057] The inner cavity of the firing section is expanded, the surface area of ​​the kiln body is increased, and the coating is increased. At the same time, baffles are added, which further increases the surface area and coating. During the firing process, when the amount of flue gas is constant, the flue gas velocity decreases due to the expansion of the inner cavity, which prolongs the contact time between the flue gas and the coating. After the baffles are added, the flue gas moves forward due to the obstruction effect of the baffles.

[0058] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An environmentally friendly high-temperature resistant kiln furniture for reducing nitrogen oxide emissions, comprising a kiln bottom (1), side walls (2), conveyor rollers (3), main burners (4), main gas pipes (5), auxiliary gas pipes (6), and a kiln top (7); the kiln bottom (1) and the side walls (2) on both sides together with the kiln top (7) at the top form the combustion chamber of the kiln furniture; several conveyor rollers (3) are connected between the middle parts of the two side walls (2); several main burners (4) are installed on the inner upper walls of the two side walls (2); a main gas pipe (5) is fixedly connected to the middle part of the two side walls (2) through several first fixing seats (21); each main burner (4) is connected to the main gas pipe (5) through a second conduit (51); an auxiliary gas pipe (6) is fixedly connected to the upper and lower sides of the two side walls (2) through several second fixing seats (22); each main burner (4) is connected to the auxiliary gas pipe (6) through a third conduit (61). characterized in that It also includes an auxiliary burner (8), a gas collection pipe (9), an auxiliary gas pipe (10), and a waste gas guide plate (11); several auxiliary burners (8) are installed in the middle of the kiln top (7); a gas collection pipe (9) is fixedly connected to the middle of each auxiliary burner (8); the auxiliary gas pipe (10) is fixedly connected to the upper side of the kiln top (7) through several third fixed seats (71); the upper end of each auxiliary burner (8) is connected to the auxiliary gas pipe (10); each main burner (4) located above the conveyor roller (3) introduces the auxiliary gas in the auxiliary gas pipe (6) into a corresponding gas collection pipe (9), and the waste gas guide plate (11) inside the kiln top (7) collects the nitrogen-containing gas that is not fully burned in the main burner (4) into the gas collection pipe (9), and the mixing components located between the gas collection pipe (9) and the auxiliary burner (8) mix the unburned nitrogen-containing gas with the auxiliary gas and introduce it into the auxiliary burner (8) for re-burning; Each main burner (4) is provided with an internal gas pipe (41), and a main burner (42) is fixed to the outer end of each internal gas pipe (41); the internal gas pipe (41) of each main burner (4) is connected to the main gas pipe (5) through a second conduit (51). Each main burner (4) located above the conveyor roller (3) is connected to a first conduit (43); each first conduit (43) is fixed to the inner surface of an exhaust gas guide plate (11); the upper end of each first conduit (43) is connected to a corresponding gas collecting pipe (9). The main gas pipe (5) delivers gas to the internal gas pipe (41) of each main burner (4) through the second conduit (51), and sprays it outward from the internal gas pipe (41) and main burner (42) of the main burner (4). At the same time, the auxiliary gas pipe (6) delivers auxiliary gas to the outside of the internal gas pipe (41) of each main burner (4) through the third conduit (61). Part of the combustion gas flowing through the main burner (4) enters the gas collecting pipe (9) along the first duct (43).

2. The environmentally friendly high-temperature-resistant kiln furniture with reduced nitride emission according to claim 1, characterized in that, Each auxiliary burner (8) has an auxiliary burner (81) connected to its lower end.

3. The environmentally friendly high-temperature resistant kiln furniture with reduced nitride emission according to claim 1, characterized in that, Several inclined air troughs (44) are provided on the upper side of the outer end of each main burner (4) located above the conveyor roller (3). Each inclined air trough (44) is set to be inclined upward toward the exhaust gas guide plate (11).

4. The environmentally friendly high-temperature resistant kiln furniture with reduced nitride emission according to claim 1, characterized in that, Each gas collecting pipe (9) has a main flame head (91) fixed to its lower side; each main flame head (91) is configured as a triangular structure that is narrow on the front and back sides and wide on the left and right sides.

5. The environmentally friendly high-temperature resistant kiln furniture with reduced nitride emission according to claim 1, characterized in that, Each exhaust gas guide plate (11) has a first baffle (111) fixedly attached to the lower side of the end near the gas collection pipe (9), and each first baffle (111) has a ventilation groove structure in the middle.

6. The environmentally friendly high-temperature resistant kiln furniture with reduced nitride emission according to claim 1, characterized in that, The mixing assembly includes a small motor (101), a rotating shaft (102), a first spur gear (103), a second spur gear (104), a sleeve (105), an upper annular fan wheel (106), an internal gear ring (107), a lower annular fan wheel (108), and an external gear ring (109); a small motor (101) is fixedly connected to the upper side of each air collecting pipe (9); a rotating shaft (102) is rotatably connected to the left side of each air collecting pipe (9); the output shaft of each small motor (101) is fixedly connected to a rotating shaft (102); a first spur gear (103) is fixedly connected to the lower side of each rotating shaft (102); and the lower end of each rotating shaft (102) is fixedly connected to... There is a second spur gear (104); a sleeve (105) is fixedly connected to the outer surface of each auxiliary burner (8); an upper annular fan wheel (106) is rotatably connected between each sleeve (105) and the gas collecting pipe (9); an internal gear ring (107) is fixedly connected to the lower side of each upper annular fan wheel (106); each first spur gear (103) meshes with an internal gear ring (107); a lower annular fan wheel (108) is rotatably connected to the inner lower side of each gas collecting pipe (9); an external gear ring (109) is fixedly connected to the upper side of each lower annular fan wheel (108); each second spur gear (104) meshes with an external gear ring (109).

7. The environmentally friendly high-temperature resistant kiln furniture with reduced nitride emission according to claim 1, characterized in that, It also includes a range control component and a secondary flame collector (92); each gas collecting pipe (9) has a secondary flame collector (92) slidably connected to its outer surface; the exhaust gas guide plate (11) is provided with a range control component, which includes an electric push rod (201), a slide rail (202), a second baffle (203), a third baffle (204), a first bushing (205), a second bushing (206), and a pull rod (207); each exhaust gas guide plate (11) on the left side is fixedly connected to an electric push rod (201); each electric push rod (201) has a secondary flame collector (92) fixedly connected to its telescopic end; the front and lower sides of each exhaust gas guide plate (11) are... Each of the rear sections is fixedly connected to a slide rail (202); a second baffle (203) is fixedly connected between the ends of each pair of front and rear slide rails (202) near the gas collecting pipe (9); a third baffle (204) is slidably connected between the ends of each pair of front and rear slide rails (202) away from the gas collecting pipe (9); a first bushing (205) is rotatably connected to the lower side of each third baffle (204) via a rotating shaft; a second bushing (206) is rotatably connected to the left and right sides of each auxiliary flame collector (92) via a rotating shaft; a pull rod (207) is fixedly connected between each first bushing (205) and an adjacent second bushing (206).

8. A method for preparing an environmentally friendly high-temperature-resistant kiln furniture with reduced nitride emission, characterized in that: The preparation method uses an environmentally friendly high-temperature resistant kiln furniture with reduced nitrogen oxide emissions as described in any one of claims 1-7, and includes the following steps: S1: Billet conveying, the billet is conveyed sequentially through the preheating kiln furniture, flue gas equipment, firing kiln furniture and cooling kiln furniture of the kiln furniture group by the conveying equipment; S2: Heating and firing, gas and auxiliary gas are introduced into the main burner (4) and auxiliary burner (8) and ignited, so that the main burner (4) and auxiliary burner (8) spray flames to uniformly heat and fire the blanks on the conveying equipment; S3: Exhaust gas collection, collecting the incompletely burned nitrogen oxide gas discharged from the main burner (4) into the auxiliary burner (8) and mixing it with the fuel gas and auxiliary fuel gas; S4: Exhaust gas re-combustion, which re-combusts the mixed unburned nitrogen oxide gas, fuel gas and combustion-supporting gas in the auxiliary burner (8) to improve the combustion efficiency of nitrogen-containing gas and reduce the emission of harmful nitrogen oxides.

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