A large multi-stage premixed gas hot air furnace

Abstract

The present invention discloses a large multi-stage premixed gas hot blast furnace, which belongs to the technical field of industrial combustion blast furnaces, including a furnace body, a first main gas pipeline and a branch gas pipeline for introducing gas, and an air inlet on the furnace body; a mixing area for facilitating the mixing of gas and air, a plurality of mutually sleeved flow dividers fixed to the furnace body are arranged in the mixing area, the first main gas pipeline is located at the center of the innermost flow divider, and the branch gas pipeline is fixed to the outer wall of the innermost flow divider; a first pipeline and a second pipeline are fixedly arranged on the outermost flow divider, the air inlet is connected to the first pipeline, and the first pipeline extends to one end of the furnace body for combustion and then bends back to the mixing area, one end of the second pipeline extends into the mixing area, and the other end extends into one side of the furnace body for combustion. The present invention is used to solve the problems of insufficient and unstable combustion caused by the heat recovery process of the gas blast furnace.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial combustion air furnaces, in particular to a large multi-stage premixed gas hot air furnace. Background Art

[0002] Industrial combustion furnaces mainly provide heat energy for various heat-using equipment. They are a commonly used energy supply equipment. They can be divided into many types based on their energy consumption methods. Among them, gas furnaces are the most widely used equipment.

[0003] As an energy supply equipment, combustion effect is its important technical indicator. On the one hand, it is necessary to keep the gas fully burned to provide more heat energy, and on the other hand, to reduce energy loss. At present, more and more companies are using the smoke return duct method to mix the smoke generated by combustion into the air for recycling. Although this method can recover part of the heat energy to a certain extent, the reuse of the flue gas reduces the oxygen content in the air. In this way, the combustion process will produce more nitrogen oxides and the stability of combustion will also be affected. Therefore, many gas-fired air furnaces currently have many problems in heat recovery and full combustion. Therefore, a multi-stage premixed gas-fired air furnace is proposed, which can partially recover and reuse the heat of the air furnace while maintaining stable and full combustion. Summary of the invention

[0004] In view of the above problems, the present invention provides a large multi-stage premixed gas hot blast furnace, which is used to solve the problems of incomplete and unstable combustion caused by the heat recovery process of the gas blast furnace.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A large multi-stage premixed gas hot air furnace comprises a furnace body, wherein the furnace body is provided with a first main gas pipeline and a branch gas pipeline for introducing gas, and an air inlet is also arranged on the furnace body;

[0007] The furnace body is provided with a mixing area for mixing gas and air, and a plurality of mutually sleeved flow dividers fixed to the furnace body are arranged in the mixing area, the first main gas delivery pipe is located at the center of the innermost flow divider, and the branch gas delivery pipe is fixed to the outer wall of the innermost flow divider;

[0008] A first pipe and a second pipe are fixedly arranged on the outermost diverter, the air inlet is connected to the first pipe, and the first pipe extends to one end of the furnace body combustion and then bends back into the mixing area, one end of the second pipe extends into the mixing area, and the other end extends into the side of the furnace body combustion.

[0009] Compared with the prior art, the beneficial effects of the present invention are as follows: by setting up a multi-section socket-arranged diverter, the introduced air can be isolated in layers, so that the introduced air can be introduced in multiple stages to participate in combustion, which can increase the mixing effect of gas and air when they are mixed and burned, and reduce the generation of nitrogen oxides in the gas combustion process by continuously replenishing air. Under the action of the first pipe, the introduced air can be first preheated on the combustion side and then returned to participate in combustion. During the preheating process, the air can cool the furnace body, which can not only protect the furnace body, but also collect and utilize the heat dissipated from the wall of the furnace body, and can further recover the heat without affecting the combustion stability of the gas. Secondly, under the action of the second pipe, part of the flue gas can be refluxed to participate in combustion. This method of flue gas recovery and utilization for combustion will not reduce the oxygen content in the incoming air, can increase the combustion effect, and reduce harmful substances in the flue gas.

[0010] As a further improvement of the above solution, a guide pipe is provided in the mixing area, the axis of the guide pipe is parallel to the axis of the furnace body, and one end of the outlet of the first pipe and the second pipe is bent toward the axis of the furnace body and is connected to the guide pipe;

[0011] The first pipeline is fixed on the outer side wall of the outermost flow dividing piece, and the second pipeline is fixed on the inner side wall of the outermost flow dividing piece.

[0012] The technical effect of the above improvement is: through the provision of the guide pipe, the air introduced at the air inlet can be accelerated through the inside of the guide pipe, so that during the rapid flow of the airflow in the guide pipe, the preheated air in the first pipe and the reflux smoke introduced on the second pipe will be sucked into the guide pipe and mixed with the air.

[0013] As a further improvement of the above scheme, an isolation plate is fixedly provided at the air outlet end of the innermost diverter and the middle diverter, and a spray hole for facilitating the spraying of gas and air is provided on the isolation plate, and a plurality of swirl holes are also provided at the edge of the isolation plate.

[0014] As a further improvement of the above solution, a plurality of flow dividers are arranged at intervals, and first swirl sheets for swirl the air are fixedly provided in the intervals.

[0015] The technical effect of the above improvement is that the swirl hole and the first swirl plate are used to swirl the mixed air and gas, thereby providing a better combustion effect.

[0016] As a further improvement of the above solution, a nozzle is provided at the end of the first main air supply pipe, and a plurality of air outlet holes facing the surroundings are provided on the nozzle, and a fan blade is also rotatably provided at the end of the nozzle;

[0017] The end of the branch gas transmission pipe is arranged to be inclined toward the central axis of the flow dividing piece.

[0018] The technical effect of the above improvement is: the air outlet arranged on the nozzle can make the introduced gas disperse quickly to the surroundings, and under the blowing of the introduced air, the fan blades rotate quickly, thereby stirring the mixed air and gas, mixing them evenly, to provide a better combustion effect.

[0019] As a further improvement of the above solution, an air distribution plate is provided on the air inlet, and a plurality of ventilation holes are provided on the air distribution plate;

[0020] A rotating seat is rotatably arranged in the furnace body, a driving source for driving the rotating seat is connected to the rotating seat, an adjusting piece that fits with the air equalizing plate is fixedly arranged on the rotating seat, and the adjusting piece is provided with adjusting holes that can overlap with the ventilation holes to increase the number of air outlets from the ventilation holes.

[0021] As a further improvement of the above solution, an air guide is fixedly arranged on the rotating seat, the air guide is arranged toward one side of the flow divider, and is rotatably arranged with the first main air pipe and the branch air pipe;

[0022] A plurality of matching grooves are arranged on the air guide body, and a spirally arranged second swirl plate is movably arranged in the matching groove. The second swirl plate is fixedly arranged on the first main air pipe, and is slidably arranged between the branch air pipe, and the first main air pipe and the furnace body are slidably arranged between each other.

[0023] The technical effect of the above improvement is: the arranged wind uniformity plate can ensure that the air enters the furnace body evenly when passing through the ventilation holes, and converges to the middle under the guidance of the air guide body, and the arranged adjustment member is mainly to adapt to different combustion requirements and adjust the amount of introduced air, so that the ratio of gas and air can be adjusted to ensure stable combustion. When the air guide body follows the rotation adjustment of the rotating seat, it can synchronously drive the second swirl plate to slide in and out of the matching groove. When the second swirl plate slides out completely, the wind can be swirled in a large range under the guiding action of the second swirl plate. During the large-scale swirl, the first main gas pipe is closer to the combustion end side of the furnace body, so that the flame of the furnace body combustion can be more diffused. On the contrary, when the first main gas pipe is away from the combustion end side of the furnace body, the swirl of the wind is reduced and the flame is more converged to the middle.

[0024] As a further improvement of the above scheme, a tee is fixedly provided at one air inlet end of the furnace body, a second main gas pipe interconnected with the first main gas pipe is provided in the tee, the branch gas pipe passes through the tee, and one end of the tee is connected to a gas main pipe respectively connected to the branch gas pipe and the second main gas pipe.

[0025] As a further improvement of the above solution, a plurality of through holes are respectively provided on the branch gas pipe and the second main gas pipe located in the tee pipe, and shielding members covering the through holes are also fixedly provided on the branch gas pipe and the second main gas pipe respectively;

[0026] The other end of the three-way pipe is connected with a regulating valve which injects air into the three-way pipe after being opened.

[0027] As a further improvement of the above solution, the shielding member is in the shape of a sleeve with its opening facing one side of the regulating valve, and there is a gap between the shielding member and the through hole to facilitate air circulation.

[0028] The technical effect of the above improvement is: through the setting of the gas main pipe, the injected gas can be dispersed into the first main gas pipe and the branch gas pipe to realize staged injection and combustion; when the combustion process is completed, the gas in the gas main pipe will be shut off first. At this time, by opening the regulating valve, under the condition of continuous air intake at the air inlet, the air entering the three-way pipe can enter the second main gas pipe and the first main gas pipe to squeeze out the excess gas for combustion, thereby avoiding residue. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0030] Figure 2 for Figure 1 Structural diagram of the middle A direction;

[0031] Figure 3 for Figure 1 A schematic diagram of the local enlarged structure at B in the middle;

[0032] Figure 4 for Figure 1 A schematic diagram of the local enlarged structure at C in the middle;

[0033] Figure 5 for Figure 1 Schematic diagram of the cross-sectional structure in the DD direction.

[0034] In the figure: 10, furnace body; 101, mixing area; 11, first main gas pipeline; 111, nozzle; 112, fan blade; 12, branch gas pipeline; 13, air inlet; 14, diverter; 141, isolation plate; 142, spray hole; 143, swirl hole; 15, first pipeline; 16, second pipeline; 17, guide pipe; 18, first swirl plate; 19, wind equalizing plate; 191, ventilation hole; 20, rotating seat; 21, adjusting member; 211, adjusting hole; 22, air guide body; 221, matching groove; 23, second swirl plate; 24, three-way pipe; 25, second main gas pipeline; 26, gas main; 27, through hole; 28, shielding member; 29, regulating valve. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the technical solution, the present invention is described in detail below in conjunction with embodiments. The description in this section is only exemplary and explanatory and should not have any limiting effect on the scope of protection of the present invention.

[0036] like Figure 1-5 As shown, the specific scheme of this embodiment is: a large multi-stage premixed gas hot blast furnace, including a furnace body 10, the furnace body 10 has a first main gas pipeline 11 and a branch gas pipeline 12 for introducing gas, such as Figure 1 As shown, the first main gas pipeline 11 is arranged in the middle position, and a plurality of branch gas pipelines 12 are arranged in a ring array around the first main gas pipeline 11. An air inlet 13 is also provided on the furnace body 10, so that the air introduced into the air inlet 13 is mixed with the gas introduced from the first main gas pipeline 11 and the branch gas pipeline 12 and then burned;

[0037] The furnace body 10 has a mixing area 101 for mixing gas and air. The mixing area 101 is provided with a plurality of flow dividers 14 which are fixed to the furnace body 10 and are arranged in a sleeve-connected manner. Specifically, in this embodiment, the flow divider 14 is provided with three flow divider pipes which are sleeve-connected and fixed to each other from small to large. Figure 1 As shown, the flow dividers 14 are arranged at intervals, that is, there is a space between every two flow dividers 14 for air circulation, and the outermost flow divider 14 is the longest, and the innermost flow divider 14 is the shortest, and a first swirl sheet 18 for swirling the air is fixedly arranged in the interval between the flow dividers 14; the first main gas pipe 11 is located at the center of the innermost flow divider 14, and the branch gas pipe 12 and the outer wall of the innermost flow divider 14 are fixed to each other, so that in the mixing process, the first stage of premixing is achieved between the air circulating in the first main gas pipe 11 and the innermost flow divider 14, and the second stage of premixing is achieved with the gas sprayed from the branch gas pipe 12 and the air sent over, and the air in the interval between the outermost flow divider 14 and the furnace body 10 can be further mixed with the burning flame to achieve full combustion and reduce the effect of nitrogen oxides in the combustion process;

[0038] The first pipe 15 and the second pipe 16 are fixedly arranged on the outermost flow divider 14. The air inlet 13 is connected to the first pipe 15, and the first pipe 15 extends to the end of the furnace body 10 for combustion, and then bends back to the mixing area 101. The air introduced through the air inlet 13 can be injected into the first pipe 15. After passing through the first pipe 15, the air exchanges heat with the furnace body 10 and the side wall of the flow divider 14, thereby recycling the heat and realizing the preheating treatment of the air. In addition, the cold air injected into the first pipe 15 , the furnace body 10 and the diverter 14 can be cooled, thereby protecting the furnace body 10 and the diverter 14. One end of the second pipe 16 extends into the mixing area 101, and the other end extends into the combustion side of the furnace body 10. The second pipe 16 is mainly used to return the flue gas generated during the combustion process to the mixing area 101 and then participate in the combustion. In this way, the flue gas can be recycled and utilized, and the oxygen content in the introduced air will not be reduced, thereby making the combustion effect better and the flue gas after combustion will not produce more pollutants.

[0039] like Figure 1 As shown, as a preferred embodiment of the above embodiment, a guide pipe 17 is provided in the mixing area 101, the axis of the guide pipe 17 is parallel to the axis of the furnace body 10, and a plurality of guide pipes 17 are provided in a central array. The opening of the guide pipe 17 on one side facing the air inlet 13 is a trumpet-shaped opening, which can facilitate the introduction of air through the guide pipe 17. One end of the outlet of the first pipe 15 and the second pipe 16 is bent toward the axis of the furnace body 10 and is interconnected with the guide pipe 17. Under the influence of the air flow passing through the guide pipe 17, the air and flue gas in the first pipe 15 and the second pipe 16 are accelerated to be sucked into the guide pipe 17 and mixed with the air in the guide pipe 17, thereby realizing the recovery and suction of the air and flue gas in the first pipe 15 and the second pipe 16; the first pipe 15 is fixed to the outer wall of the outermost diverter 14, and the second pipe 16 is fixed to the inner wall of the outermost diverter 14.

[0040] like Figure 1 , 2 As shown, as a preferred embodiment of the above-mentioned embodiment, an isolation plate 141 is fixedly provided at one end of the air outlet of the innermost diverter 14 and the middle diverter 14, and a spray hole 142 is provided on the isolation plate 141 for facilitating the spraying of gas and air, and a plurality of swirl holes 143 are also provided at the edge of the isolation plate 141. After the gas and air are mixed, the mixed gas in the middle part will be directly sprayed out through the spray hole 142 for combustion, and the mixed gas in the outer part will form a swirl around the gas in the middle after passing through the swirl hole 143, thereby providing a flame with good rigidity.

[0041] As a preferred embodiment of the above-mentioned embodiment, a nozzle 111 is provided at the end of the first main gas pipe 11, and a plurality of air outlets are provided on the nozzle 111 facing in all directions. The nozzle 111 is a pipe having a diameter larger than that of the first main gas pipe 11, and the air outlets are mainly used to diffuse the ejected gas in all directions so that it can be effectively and quickly mixed with the air. A fan blade 112 is also rotatably provided at the end of the nozzle 111, and the fan blade 112 can rotate under the blowing of the introduced air flow, so that the fan blade 112 can mechanically stir and mix the air and gas; the end of the branch gas pipe 12 is inclined toward the central axis of the diverter 14, and the gas ejected from the branch gas pipe 12 is mixed again with the mixed gas in the middle, and the branch gas pipe 12 is arranged in a dispersed manner, so that the gas and air can be more easily mixed evenly during mixing.

[0042] like Figure 1 , 3 As shown in FIG. 5 , as a preferred embodiment of the above embodiment, an air balancing plate 19 is provided on the air inlet 13. The air balancing plate 19 is in a truncated cone-shaped structure and is provided with a plurality of ventilation holes 191. After the air is introduced into the air inlet 13, the air is uniformly passed through the ventilation holes 191 and enters the mixing area 101 under the action of the air balancing plate 19;

[0043] A rotating seat 20 is rotatably disposed in the furnace body 10, and a driving source is connected to the rotating seat 20 to drive the rotating seat 20 to rotate. Figure 1 , 3 As shown, in this embodiment, the driving source includes a driving motor fixedly arranged on the outside of the furnace body 10. After the motor is connected to the reducer, the output shaft end extends into the furnace body 10 and is connected to a driving gear. A gear ring that can mesh with the driving gear is also provided on the rotating seat 20. Therefore, after the motor is started, it can drive the rotating seat 20 to rotate and change its position in the furnace body 10. The rotating seat 20 is fixedly provided with an adjusting member 21 that fits with the air distribution plate 19, as shown in FIG. Figure 1 As shown, the adjusting member 21 is a cover plate with the same structure as the air balancing plate 19, and the adjusting member 21 only partially covers the air balancing plate 19 but does not completely cover it, so that wind can always pass through the ventilation hole 191 to ensure the general combustion needs. The adjusting member 21 is provided with an adjusting hole 211 that can overlap with the ventilation hole 191 to increase the amount of air outlet of the ventilation hole 191. The adjusting hole 211 is a long strip groove that completely penetrates the matching groove 221. When the ventilation hole 191 and the adjusting hole 211 gradually overlap, the air entering the mixing area 101 will increase, otherwise it will gradually decrease, thereby realizing the control of the amount of introduced air so as to maintain a better combustion ratio of gas and air.

[0044] As a preferred embodiment of the above embodiment, an air guide 22 is fixedly arranged on the rotating seat 20, and the air guide 22 is arranged toward the side of the diverter 14. Specifically, the air guide 22 has a conical structure, with one end of the tip facing the diverter 14, and is rotated relative to the first main air pipe 11 and the branch air pipe 12. Figure 1 As shown, a connecting seat is fixedly provided on the first main gas pipeline 11 and the branch gas pipeline 12, and the connecting seat and the air guide body 22 are rotatably provided with each other;

[0045] The air guide body 22 is provided with a plurality of matching grooves 221, which can be referred to in the attached Figure 5 As shown, a spirally arranged second swirl sheet 23 is movably provided in the matching groove 221, the second swirl sheet 23 is fixedly provided on the first main gas pipe 11, and is slidably provided with respect to the branch gas pipe 12. Specifically, a mounting seat for mounting and supporting the second swirl sheet 23 is provided among the plurality of second swirl sheets 23, the mounting seat is fixedly provided with respect to the first main gas pipe 11, and is slidably provided with respect to the branch gas pipe 12, and the first main gas pipe 11 and the furnace body 10 are slidably provided with respect to each other. In the specific use process, the driving source provided on the furnace body 10 can drive the rotating seat 20 to rotate, thereby adjusting the air intake amount on the air balancing plate 19, and at the same time can bring The moving air guide body 22 rotates together, and during the rotation process, the second swirl piece 23 will slowly slide out of the matching groove 221. Under the guidance of the matching groove 221, the second swirl piece 23 will continue to move toward the side of the diverter 14, thereby driving the first main gas pipe 11 to move toward the side of the diverter 14. The diverter 14 reduces the convergence effect of the gas in the first main gas pipe 11, making the final combustion flame more dispersed. At the same time, the second swirl piece 23 extends from the matching groove 221 for a long length, which can effectively swirl the introduced air. Therefore, after a large amount of air enters, it is mixed with the gas more quickly.

[0046] Secondly, another embodiment is provided. Specifically, the rotating seat 20 and the air guide body 22 are not fixed to each other, but can be rotatably arranged with respect to each other. A slide groove is arranged on the air guide body 22, and a sliding pin which can be inserted into the slide groove is arranged on the rotating seat 20. In this way, the rotating seat 20 can realize independent control of the air flow within a certain range during the rotation process. When the extension amount of the second swirl plate 23 needs to be controlled, it only needs to control the rotating seat 20 to rotate a certain angle, which can be achieved under the mutual push and cooperation of the sliding pin and the slide groove. In this way, both independent control of flow regulation and integrated synchronous control can be achieved, and the control effect is better.

[0047] like Figure 1 , 4As shown, as a preferred embodiment of the above embodiment, a tee pipe 24 is fixedly provided at one air inlet end of the furnace body 10, and a second main gas pipe 25 interconnected with the first main gas pipe 11 is provided in the tee pipe 24. After the second main gas pipe 25 passes through the furnace body 10, it is mutually sleeved and connected with the first main gas pipe 11, so as to meet the sliding requirements of the first main gas pipe 11. The branch gas pipe 12 passes through the tee pipe 24, and one end of the tee pipe 24 is connected with a gas main pipe 26 which is respectively connected with the branch gas pipe 12 and the second main gas pipe 25. The gas introduced from the gas main pipe 26 enters the branch gas pipe 12 and the second main gas pipe 25 respectively, and can realize graded transportation, so as to facilitate better mixing in the mixing area 101.

[0048] A plurality of through holes 27 are respectively provided on the branch gas pipe 12 and the second main gas pipe 25 located in the three-way pipe 24, and shielding members 28 covering the through holes 27 are also fixedly provided on the branch gas pipe 12 and the second main gas pipe 25, respectively. The shielding member 28 is in the shape of a sleeve with its opening facing one side of the regulating valve 29, and there is a gap between the shielding member 28 and the through holes 27 for air circulation; the other end of the three-way pipe 24 is connected to a regulating valve 29 for injecting air into the three-way pipe 24 after opening, and the regulating valve 29 is opened only after the gas supply is stopped. After the regulating valve 29 is opened, since air is still being introduced into the air inlet 13, the residual gas in the second main gas pipe 25, the branch gas pipe 12 and the first main gas pipe 11 can be drawn into the mixing area 101 to participate in combustion, thereby reducing the residual gas.

[0049] The specific working principle of the present invention is as follows: the gas is injected into the branch gas pipe 12, the second main gas pipe 25 and the first main gas pipe 11 through the gas main pipe 26, and the air is introduced through the air inlet 13, and after passing through the air balancing plate 19, the air is evenly introduced into the mixing area 101 to mix with the injected gas. The gas is transported by the branch gas pipe 12 and the first main gas pipe 11 and the air is diverted by multiple diverters 14, so that the gas and the air can be premixed at multiple stages to improve the rigidity of the combustion flame after ignition.

[0050] For some situations where combustion needs to be changed, the driving source connected to the rotating seat 20 is started to control the rotation of the rotating seat 20, thereby driving the air distribution plate 19 to rotate, so that the air volume entering the mixing area 101 can be adjusted and changed, and the second swirl plate 23 can be extended and the active position of the first main gas pipeline 11 can be controlled synchronously, so that the incoming wind becomes a swirl to improve the mixing with the gas, and when the first main gas pipeline 11 is controlled to move, the dispersion and convergence of part of the flame can be controlled, which is suitable for the special needs of some equipment;

[0051] After the combustion is completed, the regulating valve 29 is controlled to open, and the residual gas in the branch gas pipe 12, the second main gas pipe 25, and the first main gas pipe 11 can be squeezed out and burned under the continuous circulation of air introduced into the air inlet 13, thereby reducing the residual gas in the pipeline.

[0052] It should be noted that, in this article, the terms include, contain or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. Specific examples are used in this article to illustrate the principle and implementation of the technical solution of the present invention. The above examples are only used to help understand the method of the present invention and its core idea. The above is only a preferred implementation of the present invention. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements, modifications or changes can be made, and the above technical features can also be combined in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the concept and technical solution of the invention to other occasions without improvement, should be regarded as the protection scope of the present invention.

Claims

1. A large multi-stage premixed gas hot air stove, characterized in that: The furnace body (10) comprises a first main gas pipeline (11) and a branch gas pipeline (12) for introducing gas into the furnace body (10), and an air inlet (13) is also arranged on the furnace body (10); The furnace body (10) has a mixing area (101) for facilitating mixing of gas and air, and the mixing area (101) is provided with flow dividers (14) which are arranged in a sleeve-type arrangement, the flow dividers (14) and the furnace body (10) are fixed to each other, the first main gas supply pipe (11) is located at the center of the innermost flow divider (14), and the branch gas supply pipe (12) and the outer wall of the innermost flow divider (14) are fixed to each other; A first pipe (15) and a second pipe (16) are fixedly arranged on the outermost flow divider (14); the air inlet (13) is connected to the first pipe (15); the first pipe (15) extends toward one end of the furnace body (10) for combustion and then bends back into the mixing area (101); one end of the second pipe (16) extends into the mixing area (101) and the other end extends into the side of the furnace body (10) for combustion; A flow guide pipe (17) is provided in the mixing area (101); the axis of the flow guide pipe (17) is parallel to the axis of the furnace body (10); outlet ends of the first pipe (15) and the second pipe (16) are bent toward the axis of the furnace body (10) and are in communication with the flow guide pipe (17); The first pipe (15) is fixed on the outer side wall of the outermost flow dividing piece (14), and the second pipe (16) is fixed on the inner side wall of the outermost flow dividing piece (14).

2. A large multi-stage premixed gas hot blast stove according to claim 1, characterized in that: An isolation plate (141) is fixedly provided at the air outlet end of the innermost flow divider (14) and the middle flow divider (14), and a spray hole (142) is provided on the isolation plate (141) for facilitating the spraying of gas and air, and a plurality of swirl holes (143) are also provided at the edge of the isolation plate (141).

3. A large multi-stage premixed gas hot blast stove according to claim 1, characterized in that: The plurality of flow dividers (14) are arranged at intervals, and first swirl sheets (18) for swirl air are fixedly arranged in the intervals.

4. A large multi-stage premixed gas hot blast stove according to claim 1, characterized in that: A nozzle (111) is provided at the end of the first main air delivery pipe (11), the nozzle (111) is provided with a plurality of air outlet holes facing in all directions, and a fan blade (112) is rotatably provided at the end of the nozzle (111); The end of the branch gas transmission pipe (12) is arranged to be inclined toward the central axis of the flow dividing member (14).

5. A large multi-stage premixed gas hot blast stove according to claim 1, characterized in that: An air distribution plate (19) is provided on the air inlet (13), and a plurality of ventilation holes (191) are provided on the air distribution plate (19); A rotating seat (20) is rotatably arranged in the furnace body (10), and a driving source for driving the rotating seat (20) is connected to the rotating seat (20). An adjusting member (21) that fits with the air distribution plate (19) is fixedly arranged on the rotating seat (20), and an adjusting hole (211) that can overlap with the ventilation hole (191) to increase the amount of air discharged by the ventilation hole (191) is arranged on the adjusting member (21).

6. A large multi-stage premixed gas hot blast stove according to claim 5, characterized in that: An air guide body (22) is also fixedly disposed on the rotating seat (20), the air guide body (22) being disposed toward one side of the flow divider (14) and being rotatably disposed relative to the first main air supply pipe (11) and the branch air supply pipe (12); The air guide body (22) is provided with a plurality of matching grooves (221), and spirally arranged second swirl sheets (23) are movably arranged in the matching grooves (221). The second swirl sheets (23) are fixedly arranged on the first main air supply pipe (11), and are slidably arranged between the second main air supply pipe (12), and between the first main air supply pipe (11) and the furnace body (10).

7. A large multi-stage premixed gas hot blast stove according to claim 1, characterized in that: A three-way pipe (24) is fixedly provided at one air inlet end of the furnace body (10), a second main gas pipe (25) interconnected with the first main gas pipe (11) is provided in the three-way pipe (24), the branch gas pipe (12) passes through the three-way pipe (24), and one end of the three-way pipe (24) is connected to a gas main pipe (26) which is respectively connected to the branch gas pipe (12) and the second main gas pipe (25).

8. A large multi-stage premixed gas hot blast stove according to claim 7, characterized in that: A plurality of through holes (27) are respectively provided on the branch gas pipe (12) and the second main gas pipe (25) located in the tee pipe (24), and shielding members (28) for covering the through holes (27) are also fixedly provided on the branch gas pipe (12) and the second main gas pipe (25). The other end of the three-way pipe (24) is connected to a regulating valve (29) which, when opened, injects air into the three-way pipe (24).

9. A large multi-stage premixed gas hot blast stove according to claim 8, characterized in that: The shielding member (28) is in the shape of a sleeve with its opening facing one side of the regulating valve (29), and a gap is provided between the shielding member (28) and the through hole (27) to facilitate air circulation.

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