Coal crushing and feeding device for circulating fluidized bed boiler

Abstract

The utility model belongs to the technical field of coal burning equipment, and particularly relates to a circulating fluidized bed boiler coal crushing and feeding device which comprises a feeding box, a feeding port is formed in the top of the feeding box, a discharging port is formed in the bottom of the feeding box, the discharging port is communicated with a boiler, a crushing mechanism is arranged below the feeding port, and a conveying platform is arranged below the crushing mechanism. The conveying outlet of the conveying platform is provided with the backflow mechanism, the outlet of the backflow mechanism is in butt joint with the feeding port, and large-particle coal crushed by the crushing mechanism is conveyed to the material returning mechanism through screening of the conveying platform and is conveyed to the feeding port again to be crushed again, so that the coal is fully crushed before entering the circulating fluidized bed boiler; and then the coal is conveyed into the hearth for combustion, so that the conveyed coal is finer, and the treatment effect on the coal is better.

Description

Technical Field

[0001] This utility model belongs to the technical field of coal-fired equipment, specifically relating to a circulating fluidized bed coal crushing and feeding device. Background Technology

[0002] Circulating fluidized bed (CFB) boilers utilize fluidized bed combustion, representing the most advanced clean coal combustion technology in industrial applications. A typical CFB boiler system consists of a fluidized bed combustion chamber (furnace), a circulating ash separator, a fly ash return device, a tail-end heating surface, and auxiliary equipment. A feeding device at the front of the furnace is also provided to deliver coal into the furnace.

[0003] Since coal is often fed in large lumps, it usually needs to be crushed. However, existing feeding devices typically only crush the coal once, which is insufficient and results in incomplete combustion of the coal after it enters the furnace. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a circulating fluidized bed boiler coal crushing and feeding device. The device uses a transport platform to screen and transport large coal particles crushed by the crushing mechanism to a return material mechanism for re-crushing at the feed inlet. This ensures that the coal is fully crushed before entering the circulating fluidized bed boiler, thereby solving the problems mentioned in the background.

[0005] To achieve the above objectives, this utility model is implemented through the following technical solution: a circulating fluidized bed boiler coal crushing and feeding device, including a feeding box, an inlet at the top of the feeding box, an outlet at the bottom of the feeding box, the outlet being connected to the boiler, a crushing mechanism below the inlet, a transport platform below the crushing mechanism, a return mechanism at the outlet of the transport platform, and the outlet of the return mechanism being connected to the inlet.

[0006] Preferably, the return mechanism includes a return box located at the conveying outlet of the transport platform, a screw conveyor installed inside the return box, the inlet of the return box being connected to the conveying outlet of the transport platform, and the outlet of the return box being connected to the inlet.

[0007] Preferably, the inlet of the return material box is provided with a ramp-shaped guide hopper, and the outlet of the return material box is provided with a connecting pipe connected to the feed inlet.

[0008] Preferably, the crushing mechanism includes two parallel and symmetrically arranged crushing rollers below the feed inlet, and a drive mechanism for driving the two crushing rollers to rotate relative to each other is provided on one side of the crushing rollers.

[0009] Preferably, the transport platform includes a conveyor belt positioned below the crushing roller, the conveyor belt having a grid-like perforation for screening the coal material.

[0010] Preferably, when the coal crushed by the crushing roller falls onto the conveyor belt, the fine coal particles fall directly to the discharge port through the grid-like holes on the conveyor belt, while the larger coal particles are conveyed to the inlet of the return box by the conveyor belt and then transported back to the feed port by the screw conveyor for further crushing.

[0011] Preferably, the feed inlet is a funnel-shaped enlarged opening.

[0012] Preferably, the inside of the feed box is provided with two opposing inclined baffles, and the lower ends of the two inclined baffles are connected to the discharge port.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows: The circulating fluidized bed boiler coal crushing and feeding device proposed in this utility model uses a transport platform to screen and transport large coal particles crushed by the crushing mechanism to the return material mechanism for re-crushing at the feed inlet. This ensures that the coal is fully crushed before entering the circulating fluidized bed boiler and then transported to the furnace for combustion, resulting in finer coal particles and better coal processing effect.

[0014] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0015] Figure 1 Schematic diagram of the three-dimensional structure of the circulating fluidized bed coal crushing and feeding device Figure 1 .

[0016] Figure 2 Schematic diagram of the three-dimensional structure of the circulating fluidized bed coal crushing and feeding device Figure 2 .

[0017] Figure 3 This is a cross-sectional view of the circulating fluidized bed coal crushing and feeding device.

[0018] Figure 4 Schematic diagram of the three-dimensional structure of the reflux mechanism of the circulating fluidized bed coal crushing and feeding device. Figure 1 .

[0019] Figure 5 Schematic diagram of the three-dimensional structure of the reflux mechanism of the circulating fluidized bed coal crushing and feeding device. Figure 2 .

[0020] In the diagram: 1. Feeding box; 2. Inlet; 3. Outlet; 4. Crushing mechanism; 41. Crushing roller; 42. Drive mechanism; 5. Transport platform; 51. Conveyor belt; 52. Mesh-shaped holes; 6. Return mechanism; 61. Return box; 62. Screw conveyor; 63. Guide bucket; 64. Connecting pipe; 7. Inclined baffle. Detailed Implementation

[0021] The embodiments of this utility model will now be described in detail with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of this utility model. All other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this utility model.

[0022] Combination Figure 1 , Figure 2 and Figure 3 As shown, the circulating fluidized bed boiler coal crushing and feeding device includes a feeding box 1, with an inlet 2 at the top and an outlet 3 at the bottom. The outlet 3 is connected to the boiler. A crushing mechanism 4 is located below the inlet 2, and a conveying platform 5 is located below the crushing mechanism 4. A return mechanism 6 is located at the outlet of the conveying platform 5, and the outlet of the return mechanism 6 is connected to the inlet 2. Specifically, the circulating fluidized bed boiler coal crushing and feeding device, as a highly efficient and stable coal pretreatment system, fully considers the needs for coal refinement, uniform conveying, and recycling. The feeding box 1 is the core container of the entire device, made of robust and durable metal materials, such as stainless steel or wear-resistant alloy steel, to withstand the impact and wear during coal conveying. The interior of the feeding box 1 is smooth and without dead corners, facilitating smooth coal flow and reducing the risk of blockage. The top-mounted feed inlet 2 is wide and equipped with an adjustable feed gate, allowing for flexible control of the feed speed according to production needs. It also features a dust cover to prevent coal dust spillage and protect the environment. The crushing mechanism 4 is located directly below the feed inlet 2, employing methods such as hammer crushing, roller crushing, or impact crushing, the specific choice depending on the coal's characteristics and required particle size. Driven by a high-performance motor, the crushing mechanism 4 efficiently crushes large pieces of coal through high-speed rotating crushing components, ensuring uniform output coal particle size that meets the combustion requirements of a circulating fluidized bed boiler. The transport platform 5, located below the crushing mechanism 4, uses a wear-resistant belt or chain conveyor for efficient transport, smoothly and continuously conveying the crushed coal to the next process. The return mechanism 6 is a key component for coal recycling, reintroducing coal particles that do not meet the particle size requirements from the transport platform 5's outlet back into the feed inlet 2 for further crushing. This return mechanism 6 ensures efficient coal circulation within the system by controlling the return speed and flow rate. In addition, the reflux mechanism 6 is equipped with an anti-clogging device to prevent blockage caused by coal particle accumulation and ensure continuous and stable system operation. This circulating fluidized bed boiler coal crushing and feeding device, with its efficient, stable, and environmentally friendly design, provides strong technical support for the coal-fired power generation industry.

[0023] Combination Figure 1 , Figure 3 , Figure 4 and Figure 5As shown, the return mechanism 6 includes a return box 61 located at the conveying outlet of the transport platform 5. A screw conveyor 62 is installed inside the return box 61. The inlet of the return box 61 connects to the conveying outlet of the transport platform 5, and the outlet of the return box 61 connects to the feed inlet 2. Specifically, the return mechanism 6, as an important component of the circulating fluidized bed coal crushing and feeding device, aims to efficiently and smoothly reintroduce coal particles that do not meet the particle size requirements from the transport platform 5 into the crushing process, thereby achieving coal refinement and recycling. The return box 61 effectively collects coal particles from the conveying outlet of the transport platform 5. The return box 61 has a spacious interior, ensuring unobstructed flow of coal particles, and also includes a buffer zone to reduce breakage and dust caused by direct impact. The screw conveyor 62 smoothly transports coal particles from the inlet (connected to the conveying outlet of the transport platform 5) to the outlet of the return box 61 through rotating screw blades. The drive unit (such as a motor and reducer) of the screw conveyor 62 is installed outside the return box 61 and connected to the screw blades through a sealed transmission device to ensure sealing and stability during the conveying process. The inlet of the return box 61 is tightly connected to the conveying outlet of the transport platform 5 to prevent coal dust leakage. At the same time, the outlet of the return box 61 is also precisely connected to the feed inlet 2 to ensure that coal particles do not leak out during the return process, keeping the entire processing system clean and environmentally friendly. In order to achieve precise control of the return mechanism 6, the system is also equipped with corresponding control devices and sensors. By monitoring the particle size distribution and flow rate of coal particles on the transport platform 5, the control system can automatically adjust the speed and conveying capacity of the screw conveyor 62 to ensure that only coal particles that do not meet the particle size requirements are sent into the return box 61 for return processing.

[0024] Combination Figure 3 , Figure 4 and Figure 5As shown, a ramp-shaped guide hopper 63 is provided at the inlet of the return material box 61, and a connecting pipe 64 connecting to the feed inlet 2 is provided at the outlet of the return material box 61. Specifically, the special design at the inlet and outlet of the return material box 61, such as the ramp-shaped guide hopper 63 and the connecting pipe 64 connecting to the feed inlet 2, further enhances the functionality and efficiency of the return mechanism 6. The guide hopper 63 is located at the inlet of the return material box 61 and is ramp-shaped. It utilizes gravity to allow coal particles falling from the conveyor outlet of the transport platform 5 to slide naturally down the ramp into the return material box 61. The inclination angle of the ramp has been carefully calculated to ensure smooth flow of coal particles while avoiding bouncing and scattering of coal particles due to excessive angle. The guide hopper 63 is also made of wear-resistant and corrosion-resistant materials to ensure stability and durability under long-term use. Furthermore, the edges of the guide hopper 63 are rounded to reduce friction and collision between coal particles and the edges during the sliding process, further reducing the breakage rate and dust generation. The connecting pipe 64, located at the outlet of the return box 61, smoothly transports the screened and returned coal particles to the feed inlet 2 for further crushing. The design of the connecting pipe 64 fully considers the flowability and conveying efficiency of the coal particles, employing appropriate diameter and length to ensure smooth flow of coal particles within the pipe without clogging.

[0025] Combination Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, the crushing mechanism 4 includes two parallel and symmetrically arranged crushing rollers 41 below the feed inlet 2. A drive mechanism 42 is provided on one side of each crushing roller 41 to drive the two crushing rollers 41 to rotate relative to each other. Specifically, the crushing rollers 41 are the main body of the crushing mechanism 4, responsible for crushing large pieces of coal into fine particles that meet the requirements. In this design, the crushing rollers 41 are arranged in a parallel and symmetrical manner, which not only ensures uniform force on the coal during the crushing process but also improves crushing efficiency. The surface of each crushing roller 41 is covered with wear-resistant and corrosion-resistant alloy blades or toothed structures. These blades or toothed structures are precision-machined and heat-treated, possessing excellent hardness and sharpness, and can easily crush hard coal blocks. The drive mechanism 42 is the power source for the crushing rollers 41, installed on one side of the crushing rollers 41. It transmits power to the two crushing rollers 41 through a mechanical transmission device (such as gears, chains, or belts), enabling the two crushing rollers 41 to rotate relative to each other. The drive mechanism 42 typically includes components such as a motor, a reducer, and transmission parts. The motor serves as the power source, providing a stable rotational torque; the reducer reduces the motor's speed and increases the torque to meet the rotational requirements of the crushing rollers 41; the transmission components are responsible for transmitting the motor's power to the crushing rollers 41 and ensuring their synchronous and smooth rotation. During operation, coal enters the crushing mechanism 4 through the feed inlet 2, initially falling into the gap between the two crushing rollers 41. With the activation of the drive mechanism 42, the two crushing rollers 41 begin to rotate relative to each other, and the blades or toothed structures on their surfaces perform various crushing actions on the coal, including shearing, squeezing, and grinding. Under the powerful crushing force, the coal is gradually crushed into fine particles, which then fall through the gap between the crushing rollers 41 onto the conveying platform 5 below.

[0026] Combination Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, the transport platform 5 includes a conveyor belt 51 positioned below the crushing roller 41, with mesh-like holes 52 on the conveyor belt 51 for screening the coal. Specifically, the conveyor belt 51 is the main body of the transport platform 5, made of high-strength, wear-resistant, and corrosion-resistant materials such as nylon, polyester, or special alloy steel to ensure stability and durability under long-term, high-load operation. The conveyor belt 51 is driven by a motor to achieve continuous and stable conveying operations. Its width and speed can be adjusted according to actual production needs to adapt to the processing requirements of different outputs and coal characteristics. The mesh-like holes 52 are evenly distributed on the surface of the conveyor belt 51, forming a fine screen. The size and shape of these holes are carefully designed to screen according to the particle size requirements of the coal. When the crushed coal falls onto the conveyor belt 51, fine particles fall directly into the collection device below through the holes, while larger particles continue to move forward along the conveyor belt 51 for further processing or return for crushing. During operation, the crushing mechanism 4 breaks large pieces of coal into fine particles, which then fall onto the conveyor belt 51 under gravity. As the conveyor belt 51 moves continuously, the coal is transported to the mesh-like openings 52 for screening. During screening, fine particles fall through the mesh-like openings 52 into the collection device, while larger particles continue to move forward on the conveyor belt 51. If further processing or recirculation of the crushed coal is required, it can be diverted and guided by the diversion device at the end of the conveyor belt 51.

[0027] Combination Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, when the coal crushed by the crushing roller 41 falls onto the conveyor belt 51, the fine coal particles fall directly to the discharge port 3 through the grid-like holes 52 on the conveyor belt 51, while the larger coal particles are conveyed through the conveyor belt 51 to the inlet of the return box 61 and then re-conveyed to the feed port 2 by the screw conveyor 62 for further crushing. Specifically, during the operation of the circulating fluidized bed coal crushing and feeding device, the crushing roller 41, the conveyor belt 51, and the grid-like holes 52 together constitute a highly efficient screening and conveying system. After large pieces of coal are forcefully crushed by the crushing roller 41, the resulting coal particles are scattered on the conveyor belt 51 in different particle sizes, and then undergo a series of fine screening and classification processes. As the conveyor belt 51 rotates at a uniform speed, the crushed coal particles begin to spread out on it and move forward. At this time, the grid-like holes 52 play a crucial role. The size of these grid-like holes 52 is precisely calculated to allow fine coal particles smaller than a certain threshold to pass through smoothly, while intercepting larger particles. Therefore, when the coal flows through the perforated area, the fine powder, like fine sand in an hourglass, quickly and orderly passes through the grid-like holes 52 and falls directly into the discharge port 3 below. The discharge port 3 is usually connected to subsequent coal powder collection or processing equipment to ensure that the fine coal powder can smoothly enter the next production stage. At the same time, those coal particles that fail to pass through the grid-like holes 52, i.e., the larger particles, continue to move forward along the conveyor belt 51. These coarse coal particles are precisely conveyed to the inlet of the return box 61 under the guidance of the conveyor belt 51. The design of the return box 61 cleverly utilizes the principles of gravity and guidance to ensure that the coal powder can fall into it smoothly without splashing or accumulating. Once the coarse coal particles enter the return box 61, they become the "new target" of the screw conveyor 62. As the core component of the return mechanism 6, the screw conveyor 62 uses the thrust generated by the rotation of its internal spiral blades to smoothly transport the coal powder from the inlet to the outlet of the return box 61. In this process, the pulverized coal is effectively compacted and propelled forward, eventually being returned to the feed inlet 2 via connecting pipe 64. Here, the coarse pulverized coal particles are again subjected to powerful crushing by the crushing roller 41 until their particle size meets the requirements. This screening and re-crushing design not only improves the crushing efficiency and quality of the coal but also achieves refined management and recycling of the coal. By precisely controlling the crushed particle size, the stability and efficiency of boiler combustion can be ensured; while the re-crushing mechanism effectively reduces coal waste and environmental pollution. In addition, the entire process is highly automated, easy to operate, and convenient to maintain, providing a strong guarantee for the stable operation of the circulating fluidized bed boiler.

[0028] Combination Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, the feed inlet 2 is a funnel-shaped, enlarged opening. Specifically, the feed inlet 2 directly affects the smooth feeding of coal and the efficiency of subsequent processing. The design of the feed inlet 2 as a funnel-shaped, enlarged opening is primarily reflected in its gradually expanding opening size. This design allows the coal to flow naturally towards the center upon input, reducing coal accumulation and stagnation at the edges of the feed inlet 2. Simultaneously, the enlarged opening provides a larger feeding area, resulting in more uniform and continuous coal feeding, effectively improving feeding efficiency. The funnel shape also provides excellent guiding properties for the feed inlet 2. When coal is fed from above, it slides rapidly down the inclined surface of the funnel and is accurately guided to the inlet of the crushing mechanism 4. This guiding effect not only ensures smooth coal flow but also reduces collisions and wear during the feeding process, protecting the equipment and extending its service life. Because the coal may contain large impurities or particles of different sizes, traditional feed inlets 2 are prone to clogging. The funnel-shaped, enlarged opening design effectively reduces this risk. When large impurities are encountered in the coal, they are gradually broken or dispersed by gravity and friction on the inclined surface of the funnel, thus reducing the possibility of blockage. Furthermore, even in the event of a minor blockage, operators can quickly restore the flow of feed inlet 2 through simple cleaning and unblocking.

[0029] Combination Figure 1 , Figure 2 and Figure 3 As shown, the feed box 1 has two opposing inclined baffles 7 inside, with their lower ends connected to the discharge port 3. Specifically, the two opposing inclined baffles 7 inside the feed box 1 not only optimize the flow path of the coal but also enhance the stability and controllability of the feeding process. The two inclined baffles 7 are arranged opposite each other, with their slopes facing the discharge port 3. This design allows the coal fed from above the feed box 1 to naturally slide down the slopes of the inclined baffles 7 and be guided by gravity towards the discharge port 3. This guiding effect ensures that the coal flows smoothly and orderly out of the feed box 1, avoiding accumulation and stagnation within the box. The lower ends of the two inclined baffles 7 are connected to the discharge port 3, ensuring that the coal smoothly enters the discharge port 3 and flows to subsequent processing equipment when it slides to the bottom of the inclined baffles 7.

[0030] The above are merely preferred embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this utility model, based on the technical solution and inventive concept of this utility model, should be included within the scope of protection of this utility model.

Claims

1. A circulating fluidized bed coal handling and crushing feeding device, comprising a feeding box (1), a feeding inlet (2) is arranged at the top of the feeding box (1), a discharging outlet (3) is arranged at the bottom of the feeding box (1), and the discharging outlet (3) is communicated with a boiler, characterized in that, The lower part of the feeding port (2) is provided with a crushing mechanism (4), and the lower part of the crushing mechanism (4) is provided with a conveying platform (5), and the conveying platform (5) conveying outlet is provided with a backflow mechanism (6), and the outlet of the backflow mechanism (6) is connected with the feeding port (2).

2. The circulating fluid bed coal-briquetting feed material processing apparatus according to claim 1, wherein The backflow mechanism (6) comprises a backflow box (61) arranged at the conveying platform (5) conveying outlet, a spiral conveyor (62) is arranged in the backflow box (61), the inlet of the backflow box (61) is connected with the conveying platform (5) conveying outlet, and the outlet of the backflow box (61) is connected with the feeding port (2).

3. The circulating fluid bed coal-briquetting feed material processing apparatus according to claim 2, wherein The inlet of the backflow box (61) is provided with a guide hopper (63) in the form of a slope, and the outlet of the backflow box (61) is provided with a connecting pipeline (64) connected with the feeding port (2).

4. The circulating fluid bed coal-briquetting feed material processing apparatus according to claim 3, wherein The crushing mechanism (4) comprises two parallel and symmetrical crushing rollers (41) arranged below the feeding port (2), and one side of the crushing roller (41) is provided with a driving mechanism (42) for driving the relative rotation of the two crushing rollers (41).

5. The circulating fluid bed coal-briquetting feed material processing apparatus according to claim 4, wherein The conveying platform (5) comprises a conveying belt (51) arranged below the crushing roller (41), and the conveying belt (51) is provided with a grid-shaped hole (52) for screening the coal powder.

6. The circulating fluid bed coal-briquetting feed material processing apparatus according to claim 5, wherein When the crushed coal powder of the crushing roller (41) falls on the conveying belt (51), the fine coal powder directly falls into the discharge port (3) through the grid-shaped hole (52) on the conveying belt (51), and the coal powder particles are relatively large and are conveyed to the inlet of the backflow box (61) through the conveying belt (51) and are re-conveyed to the feeding port (2) through the spiral conveyor (62) for re-crushing.

7. A circulating fluid bed coal-briquetting feed material processing apparatus according to claim 6, wherein The feeding port (2) is a funnel-shaped enlarged opening.

8. The circulating fluid bed coal-briquetting feed material processing apparatus according to claim 7, wherein The inside of the feeding box (1) is provided with two opposite slope baffles (7), and the low ends of the two slope baffles (7) are connected with the discharge port (3) together.

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