A new type of wind cap for circulating fluidized bed

Abstract

The utility model discloses a novel wind cap of circulating fluidized bed, it includes the wind cap head, wind cap core pipe and annular boss, the wind cap head is bell jar type, and it is symmetrically opened to have cloth wind hole on it, the wind cap core pipe is installed on cloth wind board, the wind cap core pipe is equipped with the annular boss, the annular boss inner wall is fixedly connected with the wind cap core pipe, the annular boss outer wall is threadedly connected with the wind cap head inner wall. The utility model adopts the design that bell jar type wind cap head is symmetrically opened to have cloth wind hole, can make gas more evenly distribute, thereby more effectively fluidizes the circulating ash bottom in return material valve. Meanwhile, the threaded connection mode of annular boss and wind cap head inner wall makes it unnecessary to damage the castable like traditional wind cap when needing to replace the wind cap, reduces the difficulty and cost of replacement, improves the maintainability of equipment.

Description

Technical Field

[0001] This utility model relates to the field of boiler air distribution technology, specifically to a novel air cap for circulating fluidized beds. Background Technology

[0002] The most significant and unique feature of circulating fluidized beds (CFBs) is the repeated circulation of a large number of fuel particles within a solid particle circulation loop comprised of a combustion chamber, separation unit, and return system. During this circulation process, the amount of circulating solid particles determines the solid particle concentration within the furnace, which in turn largely determines the combustion and heat transfer within the CFB. The air cap of the return valve fluidizes the bottom of the circulating ash within the valve, and its airflow creates a concentration fluidization zone, allowing for better self-balancing of the return flow. Traditional return valves typically use mushroom-shaped air caps, but the internal environment of the return valve is harsh, causing the air caps to wear easily. Replacement requires damaging the castable refractory, making replacement difficult. Utility Model Content

[0003] The purpose of this invention is to provide a novel air cap for circulating fluidized beds to solve the problems mentioned in the background art.

[0004] To solve the above-mentioned technical problems, this utility model provides a novel air cap for circulating fluidized beds, which includes an air cap head, an air cap core tube, and an annular boss. The air cap head is bell-shaped and has symmetrical air distribution holes. The air cap core tube is installed on an air distribution plate. The annular boss is sleeved on the air cap core tube. The inner wall of the annular boss is fixedly connected to the air cap core tube, and the outer wall of the annular boss is threadedly connected to the inner wall of the air cap head.

[0005] Furthermore, the interior of the hood head includes a U-shaped groove and a connecting groove from top to bottom. The U-shaped groove communicates with the outside through the air distribution hole. The diameter of the connecting groove is larger than the maximum diameter of the U-shaped groove. The inner wall of the connecting groove is provided with internal threads, and the outer wall of the annular boss is provided with external threads.

[0006] Furthermore, the pitch of the internal thread and the external thread is Rp11 / 2.

[0007] Furthermore, the air distribution holes are inclined downwards.

[0008] Furthermore, the two ends of the hood head are provided with vertical machining surfaces adapted to the wrench.

[0009] Furthermore, the annular boss is disposed on the top of the wind cap core tube, and the distance between the top surface of the annular boss and the top surface of the wind cap core tube is less than the height of the annular boss.

[0010] Furthermore, a wear-resistant castable layer is provided between the bottom surface of the annular boss and the air distribution plate.

[0011] Furthermore, the bottom surface of the hood head is flush with the bottom surface of the annular boss.

[0012] The beneficial effects of this utility model are as follows: This utility model adopts a bell-shaped air cap head with symmetrically opened air distribution holes, which enables more uniform gas distribution, thereby more effectively fluidizing the bottom of the circulating ash in the return valve. Simultaneously, the threaded connection between the annular boss and the inner wall of the air cap head allows for replacement of the air cap without damaging the castable material, unlike traditional air caps, reducing the difficulty and cost of replacement and improving the maintainability of the equipment. Attached Figure Description

[0013] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model.

[0014] Figure 2 This is a schematic diagram of the installation structure of an embodiment of the present utility model.

[0015] Figure 3 This is a top view of the hood structure of an embodiment of the present invention.

[0016] The components include: 1. hood head; 2. hood core tube; 3. annular boss; 4. air distribution hole; 5. air distribution plate; 6. vertical machining surface; 7. wear-resistant castable layer; 8. return valve body; 9. return air chamber; 10. loosening air chamber.

[0017] 11. U-shaped groove; 12. Connecting groove. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only one embodiment of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] To make the objectives, technical solutions and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments.

[0020] In the following description, references to "an embodiment," "an embodiment," "an example," "example," etc., indicate that the described embodiment or example may include a particular feature, structure, characteristic, property, element, or limitation, but not every embodiment or example necessarily includes that particular feature, structure, characteristic, property, element, or limitation. Furthermore, the repeated use of the phrase "an embodiment according to this application," while possibly referring to the same embodiment, does not necessarily refer to the same embodiment.

[0021] like Figures 1-3 As shown, this utility model discloses a novel air cap for a circulating fluidized bed, which includes an air cap head 1, an air cap core tube 2, and an annular boss 3. The air cap head 1 is bell-shaped and has symmetrical air distribution holes 4. The air cap core tube 2 is installed on an air distribution plate 5. The annular boss 3 is sleeved on the air cap core tube 2. The inner wall of the annular boss 3 is fixedly connected to the air cap core tube 2, and the outer wall of the annular boss 3 is threadedly connected to the inner wall of the air cap head 1.

[0022] This wind cap consists of a wind cap head 1, a wind cap core tube 2, and an annular boss 3. The wind cap head 1 is bell-shaped with symmetrical air distribution holes 4 on its surface, providing a basis for uniform gas distribution. The wind cap core tube 2 is mounted on an air distribution plate 5, guiding the gas into the wind cap. The inner wall of the annular boss 3 is fixedly connected to the wind cap core tube 2. In this embodiment, the annular boss 3 and the wind cap core tube 2 are integrally molded, and their outer walls are threaded to the inner wall of the wind cap head 1. This connection method ensures the stability and detachability of the wind cap structure.

[0023] In this embodiment, the return air supplied from the return air blower enters the air chamber at the bottom of the return air chamber, and then passes through the air distribution plate 5 into the return air chamber 9 and the loosening air chamber 10 respectively. The air volume of the return air chamber 9 and the loosening air chamber 10 is automatically matched through the opening of the air cap head 1. The return air cap adopts a bell-shaped structure. To ensure sealing, the air cap core tube 2 is connected to the air distribution plate 5 by spot welding. That is, in the return valve body 8 of the circulating fluidized bed, the gas enters the interior of the air cap through the air cap core tube 2, and then is evenly sprayed out from the air distribution hole 4 on the air cap head 1. The sprayed gas fluidizes the bottom of the circulating ash in the return valve, forming a concentration fluidization zone in the return valve. During the operation of the circulating fluidized bed, a large number of fuel particles circulate repeatedly in the solid particle circulation loop composed of the combustion chamber, separation device and return system.

[0024] This invention employs a bell-shaped vent head 1 with symmetrically arranged air distribution holes 4, which enables more uniform gas distribution, thereby more effectively fluidizing the bottom of the circulating ash in the return valve. Simultaneously, the threaded connection between the annular boss 3 and the inner wall of the vent head 1 eliminates the need to damage the castable material when replacing the vent head, unlike traditional vent head designs, reducing the difficulty and cost of replacement and improving the maintainability of the equipment.

[0025] In one embodiment, the interior of the hood head 1 includes a U-shaped groove 11 and a connecting groove 12 from top to bottom. The U-shaped groove 11 is connected to the outside through the air hole 4. The diameter of the connecting groove 12 is larger than the maximum diameter of the U-shaped groove 11. The inner wall of the connecting groove 12 is provided with internal threads, and the outer wall of the annular boss 3 is provided with external threads.

[0026] The special shape of the U-shaped groove 11 helps to guide the gas to be evenly distributed to each air distribution hole 4, so that the sprayed gas can act more evenly on the circulating ash and form a stable concentration fluidization zone.

[0027] The connecting groove 12 and the annular boss 3 cooperate with each other. When the wind cap core tube 2 is inserted into the connecting groove 12 and threaded to the inner wall of the connecting groove 12, and the wind cap core tube 2 cannot be rotated, that is, when the top surface of the annular boss 3 contacts the end face of the U-shaped groove 11, the wind cap head 1 is installed in place. This allows multiple wind caps to be precisely adjusted to the same height. After installing multiple such wind caps on the air distribution plate 5 of the circulating fluidized bed, since all wind cap heads 1 are at the same height, the gas ejected from each wind cap head 1 can act on the circulating ash in the return valve on a relatively uniform plane. This makes the airflow distribution in the entire air distribution area more uniform, avoiding local airflow deviations caused by inconsistent heights of the wind cap heads 1, thereby ensuring a uniform and stable fluidization effect of the circulating ash in the return valve.

[0028] In one embodiment, the pitch Rp of the internal and external threads is 11 / 2. This prevents the fine-pitch threaded vent cap from jamming after a period of operation and also avoids air leakage when the pitch is too large.

[0029] In one embodiment, the air distribution hole 4 is angled downwards. When gas enters the interior of the air cap from the core tube 2, it is ejected through the angled downward-facing hole. This design causes the airflow direction to deviate from the centerline of adjacent air caps. Compared to horizontally or vertically upward-facing holes, the angled downward-facing hole guides the gas at a specific angle towards the bottom of the circulating ash within the return valve, rather than directly towards the surrounding air caps. This avoids cross-blowing between air caps and reduces wear on the air caps.

[0030] In one embodiment, the wind cap head 1 has vertically machined surfaces 6 at both ends adapted to a wrench. In equipment such as circulating fluidized bed boilers, there are numerous wind caps that require precise installation. The vertically machined surfaces 6 provide a stable point of leverage for installers using tools such as wrenches, enabling the wind caps to be installed accurately and quickly in the designated position, thus improving installation efficiency.

[0031] In one embodiment, the annular boss 3 is disposed on the top of the wind cap core tube 2, and the distance between the top surface of the annular boss 3 and the top surface of the wind cap core tube 2 is less than the height of the annular boss 3. That is, the distance between the top of the wind cap core tube 2 and the annular boss 3 is small, which can reduce the turning resistance of the wind cap.

[0032] In one embodiment, a wear-resistant castable layer 7 is provided between the bottom surface of the annular boss 3 and the air distribution plate 5. That is, wear-resistant castable is provided around the air cap core tube 2 to form a wear-resistant castable layer 7, which can protect the air distribution plate 5 and fix the air cap. In other words, the wear-resistant castable layer 7 protects the connection between the air distribution plate 5 and the air cap, so that the air cap can be stably fixed on the air distribution plate 5.

[0033] In one embodiment, the bottom surface of the wind cap head 1 is flush with the bottom surface of the annular boss 3. This makes the wind cap more regular and compact in its overall structure, providing a good foundation for the subsequent construction of the wear-resistant castable layer 7 and the stable fixing of the wind cap.

[0034] The above description of the disclosed embodiments enables those skilled in the art to implement or use this invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, this invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A novel air cap for a circulating fluidized bed, characterized in that: It includes a hood head, a hood core tube, and an annular boss. The hood head is bell-shaped and has symmetrical air distribution holes. The hood core tube is installed on an air distribution plate. The annular boss is sleeved on the hood core tube. The inner wall of the annular boss is fixedly connected to the hood core tube, and the outer wall of the annular boss is threadedly connected to the inner wall of the hood head.

2. A new type of wind cap for circulating fluidized bed according to claim 1, characterized in that: The interior of the hood head includes a U-shaped groove and a connecting groove from top to bottom. The U-shaped groove communicates with the outside through the air distribution hole. The diameter of the connecting groove is larger than the maximum diameter of the U-shaped groove. The inner wall of the connecting groove is provided with internal threads, and the outer wall of the annular boss is provided with external threads.

3. A novel air cap for a circulating fluidized bed according to claim 2, characterized in that: The pitch of the internal thread and the external thread is Rp11 / 2.

4. The novel air cap for a circulating fluidized bed according to claim 1, characterized in that: The air distribution holes are set at an angle downwards.

5. A novel air cap for a circulating fluidized bed according to claim 1, characterized in that: The windproof cap has vertical machining surfaces at both ends that are adapted to the wrench.

6. A novel air cap for a circulating fluidized bed according to claim 1, characterized in that: The annular boss is disposed on the top of the wind cap core tube, and the distance between the top surface of the annular boss and the top surface of the wind cap core tube is less than the height of the annular boss.

7. A novel air cap for a circulating fluidized bed according to claim 1, characterized in that: A wear-resistant castable layer is provided between the bottom surface of the annular boss and the air distribution plate.

8. A novel air cap for a circulating fluidized bed according to claim 7, characterized in that: The bottom surface of the hood head is flush with the bottom surface of the annular boss.

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