Double-sided fuel gas premixing sealed hood and sintering machine flue gas circulation system

Abstract

The present application provides a double-sided inlet fuel gas premixing sealed hood and a sintering machine flue gas circulation system, the double-sided inlet fuel gas premixing sealed hood comprises a sealed hood body, two symmetrically arranged recirculating flue gas inlet pipes are connected to the same cross-sectional area of ​​the outer circumference of the sealed hood body, a fuel gas inlet pipe is inserted into the sealed hood body, a branch pipe and two fuel gas distribution rings are provided in the sealed hood body, the fuel gas inlet pipe and the branch pipe are distributed in a T shape, the two fuel gas distribution rings are connected symmetrically to both ends of the branch pipe, and each fuel gas distribution ring corresponds to one recirculating flue gas inlet pipe.

Description

[Technical field]

[0001] This application claims priority to a Chinese patent application bearing application number 202110661065.0, filed with the China Patent Office on June 15, 2021, the entire contents of which are incorporated herein by reference.

[0002] The present application belongs to the technical field of sintering production in the metallurgical industry, and relates to a sealed hood and an exhaust gas circulation system, such as a double-sided inlet fuel gas premixing sealed hood and a sinter machine exhaust gas circulation system. [Background technology]

[0003] Sintering flue gas circulation technology is the process of briefly purifying part of the waste gas after combustion and returning it to the sintering material surface to participate in sintering again. The higher the proportion of recycled waste gas, the more significant the reduction in the amount of external flue gas discharged from the sintering machine. However, as the proportion of recycled flue gas increases, a large amount of waste gas that participated in one combustion cycle returns to the sintering material surface, making it difficult for the sintering material surface to digest and absorb the excessive amount of recycled air. At the same time, the oxygen content in the recycled waste gas is too low, which causes insufficient combustion of fuel in the sintering process and a drop in the bed layer temperature, which seriously affects the sintering production process.

[0004] CN108168324A discloses a sintering flue gas circulation uniform flow hood and a sintering system, in which the uniform flow hood comprises a flue gas distribution area, a flue gas guide area and a flue gas receiving area, which are successively connected from top to bottom, the middle part of the flue gas distribution area is connected to a flue gas inlet duct, the flue gas distribution area comprises a first stage and a second stage which are symmetrical with respect to its middle position, the cross-sectional sizes of the first stage and the second stage gradually decrease along the direction away from the middle position of the flue gas distribution area, a plurality of vertical plates are provided in the flue gas guide area to allow the flue gas to flow vertically downward, and an opening is provided at the bottom of the flue gas receiving area which leads to the material surface of the sintering cart. This application optimizes the structures of the flue gas distribution area and the flue gas guidance area, so that the flue gas reaches the flue gas receiving area after being pressure-equalized and guided by the flue gas distribution area and the flue gas guidance area, thereby ensuring that the flue gas flows uniformly on the trolley surface, avoiding the phenomenon of uneven airflow inside the hood, and stably discharging the flue gas, thereby creating conditions for the sintered material to stably absorb the flue gas.

[0005] CN105066700B discloses a sealed hot air hood device and its application, including a flue gas hood installed to cover the sintering machine at the part of the sintering machine that uses the circulating flue gas, a circulation inlet pipe is provided at the top of the flue gas hood, a stop valve is installed on the circulation inlet pipe, emergency vents are provided on both sides of the flue gas hood, and an electric valve is installed on the emergency vent, and the gap between the front and rear ends of the flue gas hood and the bed surface of the sintering material layer is sealed. This application can significantly reduce the normal temperature air leaking into the flue gas hood, ensure the circulation effect of the sintering flue gas, and at the same time, improve the uniformity of the circulating flue gas in the flue gas hood.

[0006] CN110553516A discloses an oxygen-enriched sintering flue gas circulation system and its application. The oxygen-enriched sintering flue gas circulation system includes a sintering machine, a first dust remover, a first blower, an oxygen adding system, a second dust remover, a second blower and a post-treatment unit. The oxygen adding system mixes oxygen and the circulating flue gas uniformly to ensure the stability of sintering output and quality. The detection unit detects the oxygen content in the circulating flue gas in real time, and adjusts the amount of oxygen added by the control unit. The oxygen content in the mixed flue gas is detected in real time and fed back by the control unit, and the flow rate regulator adjusts the oxygen content of the circulating flue gas to be 18-30%. The oxygen addition system described in the application has a simple structure and can accurately and quickly adjust the oxygen flow rate, thereby avoiding the defect of reducing the circulating flue gas flow rate caused by the cooling waste gas or air of the external circular cooler, and can improve the flue gas circulation rate to up to 60%, thereby improving the effect of reducing flue gas emissions.

[0007] For the problem of the distribution of the flow field in the sealed hood, the relevant technology proposes optimizing the distribution of the flow field in the sealed hood by sealing and guiding, etc., in order to digest and absorb more recirculating flue gas, but as the flue gas recirculation ratio increases to more than 30%, the flue gas volume becomes huge, and the impact kinetic energy of the flue gas forms a vortex in the sealed hood, which inevitably causes the local pressure to become too high and the flue gas to overflow.For the problem of the insufficient oxygen content in the recirculating flue gas, the relevant technology proposes supplementing oxygen-enriched gas to meet the oxygen requirement of solid combustion, which is costly, and as the flue gas recirculation ratio increases, both the concentration and amount of oxygen that need to be supplemented need to be significantly increased.

[0008] Based on the above difficulties, for systems with a high circulation rate of 30% or more, it is necessary to research and develop a double-sided inlet fuel gas premixing sealed hood that can make good use of the kinetic energy of the circulating flue gas, optimize the flow field distribution in the flue gas sealed hood, enhance the fuel gas premixing effect, improve the digestion and absorption capacity of the circulating flue gas, and reduce the oxygen requirement for combustion of the sintering bed layer by. Summary of the Invention

[0009] The present application provides a double-sided inlet fuel gas premixing sealed hood and sinter flue gas circulation system.

[0010] The present application adopts the following technical proposals.

[0011] In a first aspect, the present application provides a double-sided inlet fuel gas premixing sealed hood, comprising a sealed hood body, in which two symmetrically arranged recirculating flue gas inlet pipes are connected to the same cross-sectional location on the outer periphery, a fuel gas inlet pipe is inserted therein, a branch pipe distributed in a T-shape with the fuel gas inlet pipe, and two fuel gas distribution rings are symmetrically connected to both ends of the branch pipe, each of which corresponds to one recirculating flue gas inlet pipe.

[0012] In this application, the inlet method of the double-sided inlet fuel gas premixed sealed hood is double-sided inlet, which can effectively avoid the flue gas overflowing due to excessive local pressure; the position of the two circulating flue gas inlet pipes is adjusted to improve the flue gas digestion and absorption ability of the sintering table surface; the outlet of the circulating flue gas of the double-sided inlet fuel gas premixed sealed hood is provided with a fuel gas distribution ring, which realizes sufficient and uniform mixing of the fuel gas and the circulating flue gas through counter-impinge and diffusion, thereby reducing CO2 emissions and realizing a high flue gas circulation rate of more than 30% safely and efficiently under the premise of ensuring the quality of sintered ore.

[0013] As one preferred technical solution of the present application, the sealing hood body is dome-shaped.

[0014] In addition, the present application does not require or have any special limitations on the structural features such as the size and material of the sealing hood body. The role of the sealing hood body in the present application is to provide a sealed container. Therefore, any other sealing hood body capable of achieving this type of function can be used in the present application. Those skilled in the art can understand that the size and material of the sealing hood body can be adaptively adjusted according to the usage scene and test conditions.

[0015] In one preferred technical solution of the present application, the above-mentioned recirculating flue gas inlet pipe is connected to the sealing hood body by a gradually expanding pipe stage.

[0016] Preferably, the diameter of said gradually expanding pipe stage increases gradually along the flow direction of the flue gas.

[0017] Preferably, the angle between the gradually expanding pipe stage and the horizontal plane is 15° to 75°, for example, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, but is not limited to the enumerated values, and other unenumerated values ​​within the numerical range also apply.

[0018] In addition, the gradually expanding pipe stage described in the present application may also be called the diverging pipe stage, and the present application does not require or have any special limitations on the characteristics such as the size and material of the gradually expanding pipe stage. The role of the gradually expanding pipe stage in the present application is to increase the contact area between the flue gas and the bed layer and reduce the impact of the flue gas on the bed layer. Therefore, any other gradually expanding pipe stage that can achieve this type of function can be used in the present application, and a person skilled in the art can understand that the size and material of the gradually expanding pipe stage can be adaptively adjusted according to the application scene and test conditions.

[0019] In one preferred technical solution of the present application, the fuel gas inlet pipe and the horizontal plane are perpendicular to each other.

[0020] Preferably, a fuel gas supply pipe is connected to the inlet end of the fuel gas inlet pipe.

[0021] Preferably, a control valve is provided at the connection point between the fuel gas inlet pipe and the fuel gas supply pipe.

[0022] Furthermore, the present application does not require or place any special limitations on the size, material, and other characteristics of the fuel gas inlet pipe and fuel gas supply pipe. The role of the fuel gas inlet pipe and fuel gas supply pipe in the present application is to provide a passage for fuel gas to flow. Therefore, any other fuel gas inlet pipe and fuel gas supply pipe capable of achieving this type of function can be used in the present application. A person skilled in the art can understand that the size and material of the fuel gas inlet pipe and fuel gas supply pipe can be adaptively adjusted according to the usage scene and test conditions.

[0023] In addition, the present application does not require or have any special limitations on the characteristics such as the size and material of the regulating valve. The role of the regulating valve in the present application is to control the flow rate of the fuel gas. Therefore, any other regulating valve capable of realizing this type of function can be used in the present application. Those skilled in the art can understand that the size and material of the regulating valve can be adaptively adjusted according to the usage scene and test conditions.

[0024] In one preferred technical solution of the present application, the fuel gas distribution ring comprises at least one circular perforated tube.

[0025] Preferably, said at least one circular tube with holes is distributed in concentric circles.

[0026] Preferably, the number of the at least one round of perforated circular tubes is 1 to 8 rounds, and may be, for example, 1 round, 2 rounds, 3 rounds, 4 rounds, 5 rounds, 6 rounds, 7 rounds, or 8 rounds.

[0027] Preferably, the spacing between adjacent perforated circular tubes of the at least one circumference of the perforated circular tubes is the same.

[0028] Preferably, the number of holes in each of the at least one circumference of the perforated circular tube is the same.

[0029] In addition, the present application does not require or place any special limitations on the size, material, and other characteristics of the perforated circular pipe. The role of the perforated circular pipe in this application is to circulate fuel gas, and is determined according to the size of the divergent end section of the flue gas inlet pipe and the amount of flue gas blown. Therefore, any other perforated circular pipe that can achieve this type of function can be used in the present application, and a person skilled in the art can understand that the size and material of the perforated circular pipe can be adaptively adjusted according to the usage scene and test conditions.

[0030] As one preferred technical proposal of the present application, the angle between the surface of the fuel gas distribution ring and the axis of the circulating flue gas inlet pipe is 60° to 90°, for example, 60°, 65°, 70°, 75°, 80°, 85°, 90°, but is not limited to the enumerated values, and other unenumerated values ​​within the numerical range also apply.

[0031] Preferably, the outlet end of said branch pipe is connected to the centre of a fuel gas distribution ring.

[0032] In a second aspect, the present application provides a sintering machine flue gas circulation system, which includes the above-mentioned double-sided inlet fuel gas premixed sealed hood, and further includes a belt-type sintering machine and a circulation flue, which are provided at the lower end of the sealed hood body and connected to at least ten sintering machine wind boxes at the lower end, and at least one of the at least ten sintering machine wind boxes is connected to a main flue and the circulation flue, and the flue gas passes through the at least one sintering machine wind box, enters the circulation flue and circulates, and finally returns to the sealed hood body and is sprayed onto the surface of the belt-type sintering machine.

[0033] As a preferred technical solution of the present application, the above-mentioned circulation system further includes a dust removing device and a circulation device.

[0034] Preferably, the above circulation A dust collector and a circulation device are connected to the flue gas in sequence along the flow direction of the flue gas.

[0035] Preferably, the circulation device is a circulation blower.

[0036] In addition, the present application does not require or have any special limitations on the characteristics such as the size and material of the dust removal device. The role of the dust removal device in the present application is to purify flue gas, so any other dust removal device that can achieve this type of function can be used in the present application. Those skilled in the art can understand that the size and material of the dust removal device can be adaptively adjusted according to the usage scene and test conditions.

[0037] In addition, the present application does not require or have any special limitations on the characteristics such as the size and material of the circulation device. The role of the circulation device in the present application is to circulate and circulate the flue gas. Therefore, any other circulation device capable of achieving this type of function can be used in the present application. A person skilled in the art can understand that the size and material of the circulation device can be adaptively adjusted according to the usage scene and test conditions.

[0038] As one preferred technical solution of the present application, a wind box switching valve is provided in the straight tube stage of the at least one sintering machine wind box.

[0039] In addition, in this application, the windbox switching valve generally consists of two valves, one of which is a shutoff valve for the flue gas flowing downward. When this valve is turned off, the valve that shuts off the one to the right is turned on, and the flue gas is redirected from its original downward flow into the main flue to flow into the right-hand circulation flue, that is, the flue gas enters the circulation system and is circulated and reused. Conversely, when the right valve is turned off and the lower valve is turned on, the flue gas enters the main flue, and a corresponding desulfurization and denitrification device is connected behind the main flue to treat the flue gas and then discharge it through the chimney.

[0040] In addition, the present application does not require or have any special limitations on the size, material, and other characteristics of the wind chest switching valve. The role of the wind chest switching valve in the present application is to control the flow direction of the flue gas circulation. Therefore, any other wind chest switching valve that can achieve this type of function can be used in the present application. Those skilled in the art can understand that the size and material of the wind chest switching valve can be adaptively adjusted according to the usage scene and test conditions.

[0041] In one preferred technical solution of the present application, the flue gas passes through at least one sintering machine wind box, enters the circulation flue, circulates, and finally returns to the sealed hood body, and is sprayed onto the surface of the belt-type sintering machine for sintering, completing one circulation. [Brief description of the drawings]

[0042] [Figure 1] FIG. 2 is a structural schematic diagram of a double-sided inlet fuel gas premixing sealing hood according to a specific embodiment of the present application; [Diagram 2] FIG. 2 is a structural schematic diagram of a fuel gas distribution ring according to one specific embodiment of the present application. [Diagram 3] FIG. 2 is a partial structural schematic diagram of a fuel gas distribution ring according to one specific embodiment of the present application; [Figure 4] FIG. 2 is a structural schematic diagram of a sintering machine flue gas circulation system according to a specific embodiment of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0043] In the description of this application, the orientations or positional relationships indicated by the terms "center," "longitudinal," "lateral," "up," "down," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," etc., are based on the orientations or positional relationships shown in the drawings, and are merely for the purpose of facilitating and simplifying the description of this application, and do not indicate or imply that such devices or elements must have a particular orientation, be configured and operated in a particular orientation, and therefore cannot be understood as limiting this application. In addition, the terms "first," "second," etc., are merely for the purpose of explanation, and cannot be understood as indicating or implying a relative importance or implicitly indicating the number of the technical features indicated. Thus, a feature limited by "first," "second," etc. may explicitly or implicitly include at least one of the feature. In the description of this application, unless otherwise stated, the meaning of "plurality" is at least two or more.

[0044] In the description of this application, unless otherwise clearly specified and limited, the terms "provide", "connect", and "connect" should be understood in a broad sense, and may be, for example, a fixed connection, a removable connection, an integral connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection via an intermediate medium, or an internal communication between two elements. A person skilled in the art can understand the specific meaning of the above terms in the present application according to the specific situation.

[0045] Those skilled in the art should understand that the present application necessarily includes the necessary piping, normal valves and general-purpose pump equipment to complete the process, but the above content does not belong to the main inventive point of the present application, and those skilled in the art can make their own additions and arrangements based on the selection of the process flow and equipment structure, and the present application does not make any special requirements or limitations in this regard.

[0046] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the technical solution of the present application will be described through specific embodiments with reference to the drawings.

[0047] In a specific embodiment, the present application provides a double-sided inlet fuel gas premixing sealed hood 14, as shown in Fig. 1, the double-sided inlet fuel gas premixing sealed hood 14 includes a sealed hood body 1, and for example, the sealed hood body 1 is dome-shaped. Two symmetrically arranged recirculating flue gas inlet pipes 2 are connected to the same cross-sectional area of ​​the outer circumference of the sealed hood body 1, a fuel gas inlet pipe 3 is inserted into the sealed hood body 1, and a branch pipe 5 and a fuel gas distribution ring 4 (as shown in Fig. 2 and Fig. 3) are provided in the sealed hood body 1, the fuel gas inlet pipe 3 and the branch pipe 5 are distributed in a T-shape, the fuel gas distribution ring 4 is connected symmetrically to both ends of the branch pipe 5, and each fuel gas distribution ring 4 corresponds to one recirculating flue gas inlet pipe 2.

[0048] The pipe section at the joint between the circulating flue gas inlet pipe 2 and the sealed hood body 1 is a gradually expanding pipe section 8, the diameter of which gradually increases along the flow direction of the flue gas, and illustratively the included angle between the gradually expanding pipe section 8 and the horizontal plane is 15° to 75°. The fuel gas inlet pipe 3 and the horizontal plane are perpendicular to each other, a fuel gas supply pipe is connected to the inlet end of the fuel gas inlet pipe 3, and illustratively a control valve is provided at the joint between the fuel gas inlet pipe 3 and the fuel gas supply pipe.

[0049] The fuel gas distribution ring 4 has at least one circumference of perforated circular pipes 11, and for example, the at least one circumference of perforated circular pipes 11 are distributed concentrically, the number of perforated circular pipes 11 is 1 to 8 circumferences, and specifically, the spacing between adjacent perforated circular pipes 11 among the at least one circumference of perforated circular pipes 11 is the same, the number of holes in the perforated circular pipes 11 on each circumference is the same, the angle between the surface of the fuel gas distribution ring 4 and the axis of the circulating flue gas inlet pipe 2 is 60° to 90°, and the center of the fuel gas distribution ring 4 is connected to the outlet end of the branch pipe 5.

[0050] In another specific embodiment, the circulation system of the sintering machine flue gas includes the above-mentioned double-sided inlet fuel gas premixing sealed hood 14, and further includes a belt-type sintering machine 13 and a circulation flue 20, as shown in FIG. 4, the belt-type sintering machine 13 is installed at the lower end of the sealed hood main body 1, and at least ten sintering machine wind boxes 7 are connected to the lower end of the belt-type sintering machine 13, and at least one of the at least ten sintering machine wind boxes 7 is connected to a main flue 19 and a circulation flue 20, and the flue gas passes through the at least one sintering machine wind box 7 and enters the circulation flue 20 to circulate, and finally returns to the sealed hood main body 1 and is sprayed onto the surface of the belt-type sintering machine 13.

[0051] The circulation system further includes a dust remover 16 and a circulation device. circulation flue 20 A dust removal device 16 and a circulation device are connected in sequence along the flow direction of the flue gas. For example, the circulation device is a circulation blower 15, and a wind box switching valve 17 is provided in the straight tube stage of at least one of the sintering machine wind boxes 7.

[0052] The exhaust gas passes through at least one sintering machine wind box 7, enters the circulation flue 20, circulates, and finally returns to the sealed hood body 1, where it is sprayed onto the surface of the belt-type sintering machine 13 and sintered, completing one circulation.

[0053] Example 1 This embodiment provides a double-sided inlet fuel gas premixed sealing hood 14, which is based on a specific embodiment of the double-sided inlet fuel gas premixed sealing hood 14, in which the angle between the gradually expanding pipe section 8 and the horizontal plane is 15°, the number of perforated circular pipes 11 is one round, and the angle between the surface of the fuel gas distribution ring 4 and the axis of the recirculating flue gas inlet pipe 2 is 60°.

[0054] Based on another specific embodiment of the circulation system of flue gas from a sintering machine, this embodiment provides an application method of the circulation system of flue gas from a sintering machine, in which:

[0055] The flue gas in the sintering machine wind box 7 is led out by the wind box switching valve 17 in the wind box straight tube stage 18, enters the circulation flue 20 and is sucked out, the dust is removed by the dust remover 16, and the circulation blower 15 sends it to the surface of the material layer of the sintering machine for circulating sintering. The fuel gas premixed sealed hood 14 with the two-sided inlet air is simultaneously inlet to both sides, thereby reducing the inlet air flow rate of each inlet pipe and reducing the direct impact of the large amount of circulating flue gas on the material surface. In addition, the two streams of flue gas collide and diffuse against each other to achieve a uniform distribution of the flow field inside the sealed hood, which improves the exhaust gas digestion and absorption capacity of the flue gas on the surface of the sintering material layer, and the circulation efficiency of the sintering machine flue gas circulation system is 35%.

[0056] Example 2 This embodiment provides a double-sided inlet fuel gas premixed sealing hood 14, which is based on a specific embodiment of the double-sided inlet fuel gas premixed sealing hood 14, in which the angle between the gradually expanding pipe section 8 and the horizontal plane is 30°, the number of perforated circular pipes 11 is 4, and the angle between the surface of the fuel gas distribution ring 4 and the axis of the recirculating flue gas inlet pipe 2 is 70°.

[0057] Based on another specific embodiment of the sintering machine flue gas circulation system, this embodiment provides an application method of the sintering machine flue gas circulation system, in which the flue gas in the sintering machine wind box 7 is led out by the wind box switching valve 17 in the wind box straight tube stage 18, enters the circulation flue 20 and is sucked out, is removed by the dust remover 16, and is sent to the surface of the material layer of the sintering machine by the circulation blower 15 for circulating sintering. The two-sided inlet fuel gas premixing sealed hood 14 is simultaneously inlet to both sides, thereby reducing the inlet air flow rate of each inlet pipe, reducing the direct impact of a large amount of circulating flue gas on the material surface, and the opposing collision and diffusion of the two streams of flue gas realizes a uniform distribution of the flow field in the sealed hood, thereby improving the flue gas digestion and absorption ability of the surface of the sintering material layer, and the circulation efficiency of the sintering machine flue gas circulation system is 45%.

[0058] Example 3 This embodiment provides a double-sided inlet fuel gas premixed sealing hood 14, which is based on a specific embodiment of the double-sided inlet fuel gas premixed sealing hood 14, in which the angle between the gradually expanding pipe section 8 and the horizontal plane is 75°, the number of perforated circular pipes 11 is 8, and the angle between the surface of the fuel gas distribution ring 4 and the axis of the recirculating flue gas inlet pipe 2 is 90°.

[0059] Based on another specific embodiment of the sintering machine flue gas circulation system, this embodiment provides an application method of the sintering machine flue gas circulation system, in which the flue gas in the sintering machine wind box 7 is led out by the wind box switching valve 17 in the wind box straight tube stage 18, enters the circulation flue 20 and is sucked out, is removed by the dust remover 16, and is sent to the surface of the material layer of the sintering machine by the circulation blower 15 for circulating sintering. The two-sided inlet fuel gas premixing sealed hood 14 is simultaneously inlet to both sides, thereby reducing the inlet air flow rate of each inlet pipe, reducing the direct impact of a large amount of circulating flue gas on the material surface, and the opposing collision and diffusion of the two streams of flue gas realizes a uniform distribution of the flow field in the sealed hood, thereby improving the flue gas digestion and absorption ability on the surface of the sintering material layer, and the circulation efficiency of the sintering machine flue gas circulation system is 40%.

[0060] In the present invention, two recirculating flue gas inlet pipes 2 are used to simultaneously inlet both sides of the fuel gas premixing sealed hood 14 with two inlets, thereby reducing the inlet flow rate of each inlet pipe, reducing the direct impact of a large amount of recirculating flue gas on the material surface, and the two streams of flue gas collide and diffuse to achieve a uniform distribution of the flow field in the sealed hood, improving the flue gas digestion and absorption capacity of the surface of the sintered material layer, thereby safely and efficiently achieving a high flue gas circulation rate of more than 30% under the premise of ensuring the quality of sintered ore. Meanwhile, by providing a fuel gas distribution ring 4 in the fuel gas premixing sealed hood 14 with two inlets, the kinetic energy of the recirculating flue gas entering the fuel gas premixing sealed hood 14 with two inlets and the premixing effect of the collision and diffusion are utilized to mix combustible gas into the recirculating flue gas instead of part of the sintered solid fuel, and the gas mixture is uniform, and the excess air coefficient required for homogeneous combustion is low, so that the oxygen requirement of the combustion of the sintered bed layer 6 can be reduced and the temperature of the sintered bed layer 6 can be guaranteed. The use of hydrogen-based fuel and biomass solid fuel can further reduce CO2 emissions during the sintering process. [Explanation of symbols]

[0061] 1...sealed hood body, 2...circulating flue gas inlet pipe, 3...fuel gas inlet pipe, 4...fuel gas distribution ring, 5...branch pipe, 6...sintering bed layer, 7...sintering machine wind box, 8...gradually expanding tube stage, 9...fuel gas distribution ring inlet, 10...fuel gas inlet radial branch pipe, 11...open circular tube, 12...fuel gas exhaust hole, 13...belt type sintering machine, 14...fuel gas premixed sealed hood with double-sided inlets, 15...circulating blower, 16...dust removal device, 17...wind box switching valve, 18...wind box straight tube stage, 19...main flue, 20...circulating flue

Claims

1. The hood body is provided with two symmetrically arranged recirculating flue gas inlet pipes connected to the same cross-sectional area of ​​the outer circumference, a fuel gas inlet pipe inserted therein, a branch pipe distributed in a T-shape with the fuel gas inlet pipe, and two fuel gas distribution rings symmetrically connected to both ends of the branch pipe, each of which corresponds to one recirculating flue gas inlet pipe and is located near the outlet of the corresponding recirculating flue gas inlet pipe. Premixed fuel gas sealed hood with double-sided intake.

2. The sealing hood body is dome-shaped.

2. The double-sided inlet fuel gas premixing sealed hood according to claim 1.

3. The recirculating flue gas inlet pipe is connected to the sealing hood body by a gradually expanding pipe section; 2. The double-sided inlet fuel gas premixing sealed hood according to claim 1.

4. The diameter of the gradually expanding pipe section gradually increases along the flow direction of the flue gas; 4. The double-sided inlet fuel gas premixing sealing hood according to claim 3.

5. The angle between the gradually expanding tube stage and the horizontal plane is 15° to 75°.

5. The double-sided inlet fuel gas premixing sealing hood according to claim 4.

6. The fuel gas inlet pipe and the horizontal plane are perpendicular to each other.

2. The double-sided inlet fuel gas premixing sealed hood according to claim 1.

7. A fuel gas supply pipe is connected to the inlet end of the fuel gas inlet pipe.

2. The double-sided inlet fuel gas premixing sealed hood according to claim 1.

8. A control valve is provided at the connection between the fuel gas inlet pipe and the fuel gas supply pipe.

8. The double-sided inlet fuel gas premixing sealing hood according to claim 7.

9. The fuel gas distribution ring comprises at least one circular perforated tube.

2. The double-sided inlet fuel gas premixing sealed hood according to claim 1.

10. The at least one circular tube is arranged in a concentric circle.

10. The dual inlet fuel gas premixing sealed hood of claim 9.

11. The number of the at least one circular tube having holes is 1 to 8.

10. The dual inlet fuel gas premixing sealed hood of claim 9.

12. The spacing between adjacent perforated circular tubes among the at least one circumference of the perforated circular tubes is the same. The dual inlet fuel gas premix sealing hood of claim 10.

13. The number of holes in each of the at least one circular tube is the same.

10. The dual inlet fuel gas premixing sealed hood of claim 9.

14. The angle between the surface of the fuel gas distribution ring and the axis of the recirculating flue gas inlet pipe is 60° to 90°; 2. The double-sided inlet fuel gas premixing sealed hood according to claim 1.

15. The outlet end of the branch pipe is connected to the center of the fuel gas distribution ring; 2. The double-sided inlet fuel gas premixing sealed hood according to claim 1.

16. The fuel gas premixing sealed hood with double-sided inlet according to any one of claims 1 to 15 further comprises a belt-type sintering machine provided at the lower end of the sealed hood body and having at least 10 sintering machine wind boxes connected to the lower end thereof, and a circulation flue; At least one of the at least ten sintering machine wind boxes is connected to a main flue and the circulation flue; The exhaust gas passes through the at least one sintering machine wind box, enters the circulation flue, circulates, and finally returns to the sealing hood body and is sprayed onto the surface of the belt-type sintering machine. Sintering machine flue gas circulation system.

17. Further comprising a dust removal device and a circulation device.

17. The circulation system of claim 16.

18. A dust collector and a circulation device are connected in sequence to the circulation flue along the flow direction of the flue gas; 20. The circulation system of claim 17.

19. The circulation device is a circulation blower.

20. The circulation system of claim 17.

20. A wind box switching valve is provided in the straight tube stage of the at least one sintering machine wind box.

17. The circulation system of claim 16.

21. The flue gas passes through the at least one sintering machine wind box, enters the circulation flue, and circulates, and finally returns to the sealed hood body, and is sprayed on the surface of the belt-type sintering machine to be sintered, completing one circulation.

17. The circulation system of claim 16.

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