External premixing device for fuel coal blending combustion raw material of thermal power plant

Abstract

The invention discloses an external premixing device for fuel coal blending combustion raw materials of a thermal power plant, relates to the technical field of external premixing of fuel coal, and aims to solve the problem that the raw materials are deposited at the bottom or a local area of the premixing device because different raw materials are different in physical property before fuel enters a boiler. The main shaft rod is driven to rotate through the driving motor, bottom-layer fire coal deposited on the bottom plate is extracted and poured to the screening disc through the auger, the bottom-layer fire coal and upper-layer fire coal make full contact and are mixed, traditional mixing limitation is broken, mixing uniformity is improved, and meanwhile the mixing effect is further optimized in cooperation with hot air; the transmission assembly drives a series of components to cooperatively operate when the main shaft rod rotates, the flowing direction of hot air is changed, fire coal mixing is promoted, many problems existing in a traditional out-of-furnace premixing device are effectively solved, the premixing effect and combustion performance of fire coal blending combustion in thermal power generation are improved, and energy waste and pollutant emission are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of coal premixing outside a furnace, in particular to a raw material premixing device outside a furnace for coal-fired blending in a thermal power plant. Background Art

[0002] Thermal power plant premixing equipment is used to evenly mix different types of coal or coal with other additives before the coal enters the boiler for combustion. Its purpose is to optimize the performance of the fuel, improve combustion efficiency, reduce pollutant emissions and many other advantages.

[0003] In this regard, the patent publication number CN212819207U discloses a raw material premixing device, which collects a variety of raw materials conveyed by a conveyor belt in a premixing barrel. When the raw materials in the premixing barrel are conveyed from the discharge port to the mixer, they are blocked by a flip plate and divided from the middle by the flip plate. The various materials are premixed before entering the mixer, which can significantly improve the uniformity of the mixing of the various materials, thereby ensuring the excellent quality of the finished product.

[0004] In this regard, the patent publication number CN210699884U discloses a coal-fired additive mixing device, which solves the problems of uneven mixing and low mixing efficiency in the production of coal-fired additives.

[0005] Before the fuel enters the boiler, due to the differences in physical properties of different raw materials, they are easily affected by the combined effects of gravity, friction and other factors during the mixing process, resulting in the deposition of raw materials at the bottom of the premixing device or in local areas. Once deposition occurs, it will not only destroy the uniform mixing state of the raw materials, making the fuel composition entering the boiler unstable, affecting the stability and consistency of combustion, but also the deposited raw materials may cause the blockage of the premixing device, affecting the normal operation of the equipment, increasing the frequency and difficulty of equipment maintenance, and reducing the reliability and availability of the entire power generation system.

[0006] In view of the above problems, a raw material premixing device outside the furnace for coal-fired co-firing in a thermal power plant is proposed. Summary of the invention

[0007] The purpose of the present invention is to provide a device for premixing raw materials outside the furnace for coal-fired power plants, which solves the problem of sedimentation during raw material premixing in the background technology.

[0008] To achieve the above-mentioned object, the present invention provides the following technical solution: a raw material premixing device outside the furnace for coal-fired mixed combustion in a thermal power plant, comprising a premixing bin, an over-temperature component is embedded in the interior of the premixing bin, the over-temperature component comprises an outer cover bin, an outer cover bin is embedded in the interior of the premixing bin, an inner bin is embedded in the interior of the outer cover bin, a cover plate is connected to the top of the inner bin, an inlet is provided on one side of the inner bin close to a feed pipe, and a feed port is provided on the inner wall of the inner bin;

[0009] A feed pipe is connected to one side of the premixing bin, a hot air pipe is embedded in the feed pipe, the feed pipe and the hot air pipe penetrate the interior of the premixing bin and extend to the interior of the inner bin, a balance pipe is also embedded in the premixing bin, one end of the balance pipe is embedded in the interior of the inner bin, and the other end of the balance pipe is embedded in the feed pipe, and a discharge pipe is connected to the other side of the premixing bin, and the discharge pipe is in communication with the interior of the inner bin;

[0010] The bottom end of the premixing bin is connected to a premixing assembly, which includes a driving motor, an output end of the driving motor is connected to a main shaft rod, the bottom end of the inner wall of the inner bin is connected to a bottom plate, the middle end of the inner bin is connected to a screening disc, the screening disc and the inner bin are rotatably connected, and the bottom end of the screening disc is connected to a conveying pipe.

[0011] Preferably, a channel for introducing raw materials is reserved between the outer cover bin and the inner bin, and the raw materials enter the interior of the feed pipe through the introduction port to the conveying channel, and are finally conveyed to the interior of the inner bin through the feed port.

[0012] Preferably, the hot air pipe is a tubular structure made of iron, and the hot air pipe is arranged at the center of the feed pipe, and the end thereof is embedded in the interior of the inner bin.

[0013] Preferably, the outer surface of the delivery pipe is fixedly connected with guide plates, and the inclination angles of each group of guide plates are different, and the guide plates are evenly mounted around the outer wall of the delivery pipe.

[0014] Preferably, a paddle is connected to the bottom end of the delivery tube, the bottom surface of the paddle is attached to the bottom plate, and the paddle is arranged in an arc shape.

[0015] Preferably, the main shaft rod is embedded in the interior of the conveying pipe, and an auger is provided on the outer surface of the main shaft rod. The rotation of the main shaft rod drives the auger to convey the raw materials from the bottom plate to the screening disc.

[0016] Preferably, the top end of the main shaft rod is connected with a driving gear, and the driving gear is arranged at the top end of the cover plate. The top end of the cover plate is also connected with a transmission assembly, and the transmission assembly includes a driven gear, and the driven gear is arranged at the bottom end of the cover plate and is rotatably connected to the cover plate. The bottom end of the driven gear is connected with a positioning rod, and the bottom end of the positioning rod is connected with a driving tooth. An inner nest is embedded in the driving tooth, and the bottom end of the inner nest is connected to a grinding disc. The inner nest is connected to a compression spring, and the top end of the compression spring is connected with a positioning plate, and the positioning plate is sleeved on the positioning rod.

[0017] Preferably, the driven gear and the driving gear are meshed with each other, and the grinding disc is vertically suspended on the upper surface of the screening disc.

[0018] Preferably, a transmission gear ring is connected to the edge of the screening disk, and the transmission gear ring is meshed with the driving teeth. The rotation of the main shaft drives the driving gear to rotate, thereby driving the driven gear to rotate. The rotation of the driven gear drives the driving teeth to rotate, thereby driving the transmission gear ring.

[0019] Preferably, the screening disc is arranged in the middle of the inner bin, and the screening disc divides the interior of the inner bin into two parts, an upper part and an lower part. The inlet and the feed port convey the raw materials to the bottom end of the screening disc.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention provides an off-furnace premixing device for raw materials for coal-fired co-combustion in a thermal power plant. The main shaft is driven by a driving motor to rotate, and the bottom layer of coal deposited on the bottom plate is extracted by an auger and poured onto a screening plate, so that the bottom layer and the upper layer of coal are fully contacted and mixed, breaking the limitations of traditional mixing, improving the mixing uniformity, and further optimizing the mixing effect with hot air. The transmission assembly drives a series of components to work together when the main shaft rotates, changing the flow direction of hot air to promote coal mixing, effectively solving many problems existing in traditional off-furnace premixing devices, improving the premixing effect and combustion performance of coal-fired co-combustion in thermal power generation, and reducing energy waste and pollutant emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 This is a schematic diagram of the structure of the premixing bin and the discharge pipe of the present invention;

[0024] Figure 3 It is a schematic diagram of the cross-sectional structure of the premixing bin of the present invention;

[0025] Figure 4 It is a structural schematic diagram of the driving motor and the base plate of the present invention;

[0026] Figure 5 It is a schematic diagram of the cross-sectional structure of the over-temperature component of the present invention;

[0027] Figure 6 It is a schematic diagram of the exploded structure of the over-temperature component of the present invention;

[0028] Figure 7 It is a schematic diagram of the structure of the premixing assembly of the present invention;

[0029] Figure 8 It is a schematic diagram of the exploded structure of the premixing assembly of the present invention;

[0030] Fig. 9 It is a schematic structural diagram of the transmission assembly of the present invention.

[0031] In the figure: 11, premixing bin; 12, feed pipe; 13, hot air pipe; 14, balance pipe; 15, discharge pipe; 2, overtemperature component; 21, outer cover bin; 22, inner bin; 23, cover plate; 24, inlet; 25, feed port; 3, premixing component; 31, drive motor; 32, bottom plate; 33, conveying pipe; 34, paddle; 35, screening disc; 36, transmission gear ring; 37, main shaft rod; 38, driving gear; 39, guide plate; 4, transmission component; 41, driven gear; 42, positioning rod; 43, driving gear; 44, inner nesting; 45, positioning disc; 46, compression spring; 47, grinding disc. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the accompanying drawings.

[0034] Combination Figure 1-Figure 9 The present invention discloses a raw material premixing device for coal-fired mixed combustion in a thermal power plant, comprising a premixing bin 11, an over-temperature component 2 is embedded in the premixing bin 11, the over-temperature component 2 comprises an outer cover bin 21, the outer cover bin 21 is embedded in the premixing bin 11, an inner bin 22 is embedded in the outer cover bin 21, a cover plate 23 is connected to the top of the inner bin 22, an inlet 24 is provided on the side of the inner bin 22 close to the feed pipe 12, a feed port 25 is provided on the inner wall of the inner bin 22, a channel for introducing raw materials is reserved between the outer cover bin 21 and the inner bin 22, the raw materials enter the inside of the feed pipe 12 through the inlet 24 until they enter the conveying channel, and are finally conveyed to the inside of the inner bin 22 through the feed port 25;

[0035] A feed pipe 12 is connected to one side of the premixing bin 11, and a hot air pipe 13 is embedded in the feed pipe 12. The hot air pipe 13 is a tubular structure made of iron. The hot air pipe 13 is arranged at the center of the feed pipe 12, and its end is embedded in the inner bin 22. The feed pipe 12 and the hot air pipe 13 penetrate the interior of the premixing bin 11 and extend to the interior of the inner bin 22. A balance pipe 14 is also embedded in the premixing bin 11, and one end of the balance pipe 14 is embedded in the interior of the inner bin 22, and the other end of the balance pipe 14 is embedded in the interior of the feed pipe 12. A discharge pipe 15 is connected to the other side of the premixing bin 11, and the discharge pipe 15 is connected to the interior of the inner bin 22.

[0036] In the transportation of materials, the raw materials are first transported to the interior of the premixing bin 11 through the feed pipe 12, wherein a combustion aid and a sulfur-fixing agent are added to the coal. The addition of the combustion aid can play a catalytic role in the combustion process, reduce the ignition temperature of the coal, and make the combustion more complete. In addition, the sulfur-fixing agent is added to the coal to reduce the emission of sulfur dioxide into the atmosphere;

[0037] First, the coal passes through the feed pipe 12 and the inside of the introduction port 24, and is finally transported to the inside of the inner bin 22 through the feed port 25. When the coal is inside the feed pipe 12, the coal is blown into the inside of the inner bin 22 through the blowing device. In addition, hot air is blown into the inside of the inner bin 22 through the hot air pipe 13. The addition of hot air can promote the flow of the coal inside, and part of the heat diffuses into the inside of the feed pipe 12 through the hot air pipe 13. Because the addition of coal is slow, the coal is preheated inside the feed pipe 12 at this time. The overheated coal is gradually added to the inside of the inner bin 22 for mixing, and a part of the fine particles of coal are mixed in the blowing device. Under the blowing of the wind device, the coal is directly blown into the interior of the inner warehouse 22 through the balance pipe 14. Some of the larger ones, when all the coal is transported to the interior of the inner warehouse 22, the blowing device stops. At this time, the coal cannot be transported to the interior of the inner warehouse 22 through the inlet 24 and the feed port 25. Since there is still a part of the coal in the gap between the outer cover warehouse 21 and the inner warehouse 22, this part of the coal can play the role of isolating the outlet, which also makes the interior of the inner warehouse 22 relatively sealed. In addition, as the hot air pipe 13 blows hot air into the interior of the inner warehouse 22, the coal stored in the channels of the outer cover warehouse 21 and the inner warehouse 22 can be preheated, which is convenient for the next addition.

[0038] In order to improve the mixing effect, the internal coal is mixed by driving the premixing component 3 and added for processing, so that the premixing effect is more excellent. The specific operation is as follows:

[0039] The bottom end of the premixing bin 11 is connected to a premixing assembly 3, which includes a driving motor 31. The output end of the driving motor 31 is connected to a main shaft rod 37. The bottom end of the inner wall of the inner bin 22 is connected to a bottom plate 32. The middle end of the inner bin 22 is connected to a screening disc 35. The screening disc 35 is arranged in the middle position of the inner bin 22. The screening disc 35 divides the interior of the inner bin 22 into two parts, the upper and lower parts. The inlet 24 and the feed port 25 convey the raw materials to the bottom end of the screening disc 35. The screening disc 35 is rotatably connected to the inner bin 22. The bottom end is connected to a conveying pipe 33, and a guide piece 39 is fixedly connected to the outer surface of the conveying pipe 33, and the inclination angles of each group of guide pieces 39 are different. The guide pieces 39 are evenly mounted on the outer wall of the conveying pipe 33. The bottom end of the conveying pipe 33 is connected to a paddle 34, and the bottom surface of the paddle 34 is attached to the bottom plate 32. The paddle 34 is arranged in an arc shape, and a main shaft rod 37 is embedded in the interior of the conveying pipe 33. An auger is arranged on the outer surface of the main shaft rod 37. The rotation of the main shaft rod 37 drives the auger to convey the raw materials from the bottom plate 32 to the screening disc 35.

[0040] After the coal is transported to the interior of the inner bin 22, the main shaft 37 is driven to rotate by the driving motor 31. When the main shaft 37 rotates, the coal stored on the bottom plate 32 is transported. At this time, the coal will be transported upward as the main shaft 37 drives the auger to rotate, and finally transported to the screening plate 35. At this time, the coal is poured onto the screening plate 35. Along with the holes on the screening plate 35, this part of the coal will pass through the holes and float down again. At this time, with the hot air blown in by the hot air pipe 13, the coal particles come into contact with the hot air flow, which can increase the fluidity of the coal under the action of the hot air flow, and can also increase the contact with the hot air during the flow process and preheat it.

[0041] The reason for adopting such a premixing method is that when the coal exists on the bottom plate 32, the rotation of the main shaft 37 extracts the coal deposited at the bottom, and the coal at the bottom layer is covered by the coal at the upper layer and is not easily heated. In addition, when mixing and stirring, the interaction between the coal at the bottom layer and the coal at the middle layer or the coal at the upper layer is poor. By extracting the coal at the bottom layer and sprinkling it, the coal at the bottom layer and the coal at the upper layer are in contact and mixed. Such a mixing effect breaks the defects of traditional mixing and improves the mixing efficiency.

[0042] In addition, in order to further process the coal premix, a transmission component 4 is provided to improve the effect, and the specific operation is as follows:

[0043] The top of the main shaft rod 37 is connected to a driving gear 38, which is arranged at the top of the cover plate 23. The top of the cover plate 23 is also connected to a transmission assembly 4, which includes a driven gear 41, which is arranged at the bottom of the cover plate 23 and is rotatably connected to the cover plate 23. The bottom end of the driven gear 41 is connected to a positioning rod 42, and the bottom end of the positioning rod 42 is connected to a driving tooth 43. The inside of the driving tooth 43 is embedded with an inner nest 44, and the bottom end of the inner nest 44 is connected to a grinding disc 47, and the inside of the inner nest 44 is connected to a pressure Spring 46, the top of the compression spring 46 is connected with a positioning plate 45, the positioning plate 45 is sleeved on the positioning rod 42, the driven gear 41 and the driving gear 38 are meshed with each other, the grinding disc 47 is vertically suspended on the upper surface of the screening disc 35, the edge of the screening disc 35 is connected with a transmission gear ring 36, the transmission gear ring 36 and the driving gear 43 are meshed, the main shaft rod 37 rotates to drive the driving gear 38 to rotate, thereby driving the driven gear 41 to rotate, the driven gear 41 rotates to drive the driving gear 43 to rotate, thereby driving the transmission gear ring 36 to rotate.

[0044] When the driving motor 31 drives the main shaft 37 to rotate, it drives the driving gear 38 to rotate. When the driving gear 38 rotates, it drives the driven gear 41 to rotate. When the driven gear 41 rotates, it drives the driving gear 43 to rotate, and finally drives the sieve plate 35 to rotate. In addition, the rotation of the sieve plate 35 drives the rotation of the conveying pipe 33 and the guide piece 39 and the paddle 34 at the same time. When the conveying pipe 33 rotates, the paddle 34 can make the coal scattered on the bottom plate 32 gather to the middle. Under the paddle 34, the coal gradually approaches the main shaft 37, which is convenient for the main shaft 37 For the extraction of coal, in addition, in order to change the flow direction of the hot air inside the inner bin 22, four groups of guide plates 39 are provided, and the inclination degree of each group of guide plates 39 is different. When the hot air is blown into the inner bin 22 from the hot air pipe 13, the hot air contacts the guide plates 39. At this time, the hot air will be guided by the guide plates 39. Since the angles of each group of guide plates 39 are different, and the guide plates 39 rotate with the conveying pipe 33, the flow direction of the airflow is changed by the guide plates 39. This also allows the lower layer of coal to be more freely mixed with the upper layer of coal.

[0045] Secondly, when a part of the coal is lifted up to the screening disc 35 through the main shaft rod 37, the screening disc 35 drives the teeth 43 to rotate while the teeth 43 rotates. When the teeth 43 rotate, the compression spring 46 is driven to rotate. When there are large particles of coal on the screening disc 35, the large particles of coal can be crushed by the rotation of the grinding disc 47. During the crushing process, the large particles of coal are pre-treated to ensure the quality of coal in subsequent processing.

[0046] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants 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.

[0047] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A device for premixing raw materials outside the furnace for coal-fired power plant, comprising a premixing chamber (11), characterized in that: An over-temperature component (2) is embedded in the pre-mixing bin (11), the over-temperature component (2) comprises an outer cover bin (21), the outer cover bin (21) is embedded in the pre-mixing bin (11), the inner bin (22) is embedded in the outer cover bin (21), the top of the inner bin (22) is connected to a cover plate (23), a side of the inner bin (22) close to the feed pipe (12) is provided with an inlet (24), and an inner wall of the inner bin (22) is provided with a feed port (25); A feed pipe (12) is connected to one side of the premixing bin (11), a hot air pipe (13) is embedded in the feed pipe (12), the feed pipe (12) and the hot air pipe (13) penetrate the interior of the premixing bin (11) and extend to the interior of the inner bin (22), a balance pipe (14) is also embedded in the interior of the premixing bin (11), one end of the balance pipe (14) is embedded in the interior of the inner bin (22), and the other end of the balance pipe (14) is embedded in the interior of the feed pipe (12), and a discharge pipe (15) is connected to the other side of the premixing bin (11), and the discharge pipe (15) is communicated with the interior of the inner bin (22); The bottom end of the premixing bin (11) is connected to a premixing assembly (3), the premixing assembly (3) comprises a driving motor (31), the output end of the driving motor (31) is connected to a main shaft rod (37), the bottom end of the inner wall of the inner bin (22) is connected to a bottom plate (32), the middle end of the inner bin (22) is connected to a screening disc (35), the screening disc (35) and the inner bin (22) are rotatably connected, and the bottom end of the screening disc (35) is connected to a conveying pipe (33).

2. The device for premixing raw materials outside the furnace for coal-fired power plant according to claim 1, characterized in that: A passage for introducing raw materials is reserved between the outer cover bin (21) and the inner bin (22). The raw materials enter the interior of the feed pipe (12) through the introduction port (24) to the conveying channel, and are finally conveyed to the interior of the inner bin (22) through the feed port (25).

3. The device for premixing raw materials outside the furnace for coal-fired power plant according to claim 1, characterized in that: The hot air pipe (13) is a tubular structure made of iron. The hot air pipe (13) is arranged at the center of the feed pipe (12), and its end is embedded in the interior of the inner bin (22).

4. The device for premixing raw materials outside the furnace for coal-fired power plant according to claim 1, characterized in that: The outer surface of the delivery pipe (33) is fixedly connected with a guide piece (39), and the inclination angles of each group of the guide pieces (39) are different. The guide pieces (39) are evenly mounted around the outer wall of the delivery pipe (33).

5. The device for premixing raw materials outside the furnace for coal-fired power plant according to claim 1, characterized in that: The bottom end of the delivery pipe (33) is connected to a paddle (34), the bottom surface of the paddle (34) is attached to the bottom plate (32), and the paddle (34) is arranged in an arc shape.

6. The device for premixing raw materials outside the furnace for coal-fired power plant according to claim 1, characterized in that: The main shaft rod (37) is embedded in the interior of the conveying pipe (33), and an auger is arranged on the outer surface of the main shaft rod (37). The main shaft rod (37) rotates to drive the auger to convey the raw materials from the bottom plate (32) to the screening plate (35).

7. The device for premixing raw materials outside the furnace for coal-fired power plant according to claim 1, characterized in that: The top end of the main shaft rod (37) is connected to a driving gear (38), and the driving gear (38) is arranged at the top end of the cover plate (23). The top end of the cover plate (23) is also connected to a transmission assembly (4), and the transmission assembly (4) comprises a driven gear (41), and the driven gear (41) is arranged at the bottom end of the cover plate (23) and is rotatably connected to the cover plate (23). The bottom end of the driven gear (41) is connected to a positioning rod (42), and the bottom end of the positioning rod (42) is connected to a driving tooth (43). An inner nest (44) is embedded in the driving tooth (43), and the bottom end of the inner nest (44) is connected to a grinding disc (47). The inner nest (44) is connected to a compression spring (46), and the top end of the compression spring (46) is connected to a positioning disc (45), and the positioning disc (45) is sleeved on the positioning rod (42).

8. The device for premixing raw materials outside the furnace for coal-fired power plant according to claim 7, characterized in that: The driven gear (41) and the driving gear (38) are meshed with each other, and the grinding disc (47) is vertically suspended on the upper surface of the screening disc (35).

9. The device for premixing raw materials outside the furnace for coal-fired power plant according to claim 8, characterized in that: A transmission gear ring (36) is connected to the edge of the screening disc (35), and the transmission gear ring (36) is meshed with the driving gear (43). The rotation of the main shaft (37) drives the driving gear (38) to rotate, thereby driving the driven gear (41) to rotate. The rotation of the driven gear (41) drives the driving gear (43) to rotate, thereby driving the transmission gear ring (36) to rotate.

10. The device for premixing raw materials outside the furnace for coal-fired co-firing in a thermal power plant according to claim 1, characterized in that: The screening plate (35) is arranged in the middle of the inner bin (22), and the screening plate (35) divides the interior of the inner bin (22) into two parts, an upper part and an lower part. The inlet (24) and the feed port (25) convey the raw materials to the bottom end of the screening plate (35).

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