Sealing assembly used between axial flow induced draft fan impeller and machine shell inner cylinder

Abstract

The sealing assembly used between the impeller of the axial flow induced draft fan and the inner barrel of the machine shell comprises a movable bearing component, a fixed bearing component, a fixed covering component, a movable flow blocking component and a press fit positioning component, the sealing assembly can effectively prevent external smoke from entering the position between the impeller and the inner barrel of the machine shell through cooperation of a flow blocking gear ring covering barrel shell, and therefore the sealing effect is improved. Due to the design of the flow choking gear ring, the flow speed of smoke entering the gap is slowed down, the flow is reduced, the sealing effect is further enhanced, the movable inner ring and the flow choking gear ring are made of sulfuric acid dew point corrosion resistant steel, good corrosion resistance is achieved, and the sealing device is particularly suitable for the environment containing corrosive gas; the sealing assembly has good corrosion resistance and toughness as well, stable operation of the sealing assembly in a severe environment is ensured, and the sealing assembly is reasonable in structural design, proper in material selection, not prone to damage in the using process and low in maintenance cost.

Description

Technical Field

[0001] The utility model relates to a blower, in particular to a sealing component used between an impeller of an axial flow induced draft fan and an inner cylinder of a casing. Background Art

[0002] Large thermal power units have strict energy conservation and emission reduction targets. In order to save coal and reduce consumption, a boiler exhaust system uses an economizer to recover exhaust heat to achieve cascade utilization of energy and improve unit efficiency. After the low-temperature economizer is used, the flue gas temperature is reduced from about 125℃ to 150℃ to about 85℃ to 115℃, while the dew point temperature of sulfur-containing substances is about 90℃. Once the flue gas leaks into the fan rotor, it will inevitably corrode the rotor components and damage the internal steel structure of the fan rotor. Patent document CN213574788U discloses a sealing assembly of a fan, which includes a first sealing structure and a second sealing structure. The first sealing structure is arranged in the bearing seat of the fan and is sleeved on the outside of the main shaft, and is used for sealing between the main shaft and the bearing seat. The second sealing structure is sleeved on the outside of the main shaft and fixed on the mounting plate of the fan's mounting base, and is used for sealing between the main shaft of the fan and the fan's mounting base. The first sealing structure and the second sealing structure are provided to achieve sealing between the main shaft and the bearing seat, and between the main shaft and the mounting base, to prevent leakage of the bearing seat and to block gas leakage. However, this sealing structure cannot be adapted to the fan rotor and the inner cylinder of the casing, so that it cannot play a sealing role between the fan rotor and the inner cylinder of the casing, affecting the long-term safe and stable operation of the fan. Therefore, it is necessary to optimize its structure to overcome the above-mentioned defects. Utility Model Content

[0003] The utility model aims to provide a sealing component used between an impeller of an axial flow induced draft fan and an inner cylinder of a casing, so as to improve the sealing performance of the fan.

[0004] The technical solution adopted by the utility model to solve its technical problems is:

[0005] A sealing assembly for use between an impeller of an axial flow induced draft fan and an inner cylinder of a casing, comprising:

[0006] A movable bearing member, which is mounted on the impeller and can rotate with the impeller;

[0007] A fixed bearing member, which is installed on the inner cylinder of the casing and corresponds to the position of the movable bearing member;

[0008] A fixed cover component is installed on the fixed bearing component and is adapted to the shape of the movable bearing component. The fixed cover component covers the outside of the movable bearing component, and a gap is reserved between the fixed cover component and the movable bearing component so that the movable bearing component can rotate in the fixed cover component;

[0009] A movable flow-blocking component is installed on the movable bearing component and cooperates with the fixed cover component. The movable flow-blocking component seals the gap between the fixed cover component and the movable bearing component, and blocks the process of external smoke entering the gap between the fixed cover component and the movable bearing component, so that its pressure is less than or equal to the pressure of the sealed airflow;

[0010] The pressing and positioning component is installed on the fixed covering component and is engaged with the fixed bearing component. The fixed covering component is pressed and positioned on the fixed bearing component by the pressing and positioning component.

[0011] Specifically, the movable bearing member includes:

[0012] The movable inner ring is welded to the outer wall of the impeller, extends along the circumference of the impeller, and protrudes toward the inner cylinder of the casing.

[0013] The fixed load-bearing member comprises:

[0014] The fixed outer ring is welded to the outer wall of the inner cylinder of the casing, extends along the circumference of the impeller and protrudes toward the impeller, and its diameter is greater than the diameter of the movable inner ring.

[0015] The fixed cover component comprises:

[0016] The covering cylindrical shell is installed on the inner wall of the fixed outer ring. It extends along the circumference of the impeller, protrudes toward the movable inner ring, and covers the outside of the movable inner ring. A gap is reserved between the covering cylindrical shell and the movable inner ring so that the movable inner ring can rotate in the covering cylindrical shell.

[0017] The movable flow blocking member comprises:

[0018] A choke gear ring is provided with a group, each choke gear ring is formed on the outer wall of the movable inner ring, extends along the circumference of the movable inner ring, protrudes radially toward the cover shell, and is arranged sequentially along the axial direction of the movable inner ring, forming choke recesses between adjacent choke gear rings, so that the flow velocity of external smoke entering the gap between the cover shell and the movable inner ring is slowed down and the flow rate is reduced.

[0019] The press-fit positioning component includes:

[0020] A pressing ring, which is located on the inner wall of the cover cylinder shell and presses the cover cylinder shell between the fixed outer ring and the pressing ring;

[0021] A group of positioning bolts are provided, and each positioning bolt is arranged in sequence along the circumference of the pressing ring. The positioning bolts penetrate the pressing ring, the covering cylinder shell and the fixed outer ring to connect and tighten the pressing ring, the covering cylinder shell and the fixed outer ring. The pressing ring presses the covering cylinder shell so that no significant circumferential deformation occurs when it rubs against the choke gear ring.

[0022] In one embodiment of the utility model, the movable inner ring and the choke gear ring are made of sulfuric acid dew point corrosion resistant steel (09CrCuSb), and the cover cylinder shell is made of brass. The sulfuric acid dew point corrosion resistant steel has good corrosion resistance, and brass has good corrosion resistance and good toughness. When there is friction with the rotating choke gear ring, it will not be destroyed itself, nor will it damage the choke gear ring.

[0023] The advantages of the utility model are:

[0024] The sealing component can effectively block external flue gas from entering the gap through the cooperation between the choke gear ring and the cover cylinder shell, thereby ensuring the sealing effect. The design of the choke gear ring slows down the velocity of the flue gas entering the gap and reduces the flow rate, further enhancing the sealing effect. The movable inner ring and the choke gear ring are made of sulfuric acid dew point corrosion-resistant steel, which has good corrosion resistance and is particularly suitable for environments containing corrosive gases. The cover cylinder shell is made of brass, which also has good corrosion resistance and toughness, ensuring the stable operation of the sealing component in harsh environments. The sealing component has a reasonable structural design and appropriate material selection, making it not easy to be damaged during use and having low maintenance costs. Even if parts need to be replaced, they can be easily disassembled and installed, reducing maintenance time and costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of a sealing assembly between an axial flow induced draft fan impeller and an inner cylinder of a casing proposed by the utility model;

[0026] Figure 2 is a schematic diagram of the cross-sectional structure of the sealing component;

[0027] Figure 3 yes Figure 2 A magnified close-up of point A in the middle;

[0028] Figure 4 It is a schematic diagram of the usage status of the sealing component. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the embodiment of the utility model clearer, the technical scheme in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. The components of the embodiment of the utility model generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiment of the utility model provided in the drawings is not intended to limit the scope of the utility model claimed for protection, but merely represents the selected embodiment of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the utility model.

[0030] like Figure 1 to Figure 3 As shown, the sealing assembly for the axial flow induced draft fan impeller and the inner cylinder of the casing proposed by the utility model comprises a movable bearing member, a fixed bearing member, a fixed cover member, a movable flow blocking member and a pressing and positioning member. The movable bearing member is installed on the impeller and can rotate with the impeller. The fixed bearing member is installed on the inner cylinder of the casing and corresponds to the position of the movable bearing member. The fixed cover member is installed on the fixed bearing member and is adapted to the shape of the movable bearing member. The cover is fitted on the outside of the movable bearing member. A gap is reserved between the fixed cover member and the movable bearing member so that the movable bearing member can rotate in the fixed cover member. The movable flow blocking member is installed on the movable bearing member and cooperates with the fixed cover member. The gap between the fixed cover member and the movable bearing member is sealed by the movable flow blocking member, and the process of external smoke entering the gap between the fixed cover member and the movable bearing member is blocked so that its pressure is less than or equal to the pressure of the sealing airflow. The pressing and positioning member is installed on the fixed cover member and engaged with the fixed bearing member. The fixed cover member is pressed by the pressing and positioning member to position it on the fixed bearing member.

[0031] In this embodiment, the movable bearing member includes a movable inner ring 100, which is welded to the outer wall of the impeller, extends along the circumference of the impeller, and protrudes toward the inner cylinder of the casing.

[0032] The fixed bearing member comprises a fixed outer ring 200 which is welded to the outer wall of the inner cylinder of the casing, extends along the circumference of the impeller and protrudes toward the impeller, and has a diameter greater than that of the movable inner ring.

[0033] The fixed covering component includes a covering shell 300, which is installed on the inner wall of the fixed outer ring. It extends along the circumference of the impeller, protrudes toward the movable inner ring, and covers the outside of the movable inner ring. A gap is reserved between the covering shell and the movable inner ring so that the movable inner ring can rotate in the covering shell.

[0034] The movable flow-blocking component includes a flow-blocking gear ring 400, and a group of flow-blocking gear rings are provided. Each flow-blocking gear ring is formed on the outer wall of the movable inner ring, extends along the circumference of the movable inner ring, protrudes radially toward the cover shell, and is arranged sequentially along the axial direction of the movable inner ring, and flow-blocking recesses are formed between adjacent flow-blocking gear rings, so that the flow velocity of external smoke entering the gap between the cover shell and the movable inner ring is slowed down and the flow rate is reduced.

[0035] The pressing and positioning component includes a pressing ring 510 and a positioning bolt 520. The pressing ring is located on the inner wall of the cover cylinder shell, and the cover cylinder shell is pressed between the fixed outer ring and the pressing ring. A group of positioning bolts are provided, and each positioning bolt is arranged in sequence along the circumference of the pressing ring. The pressing bolts penetrate the pressing ring, the cover cylinder shell and the fixed outer ring, and connect and tighten the pressing ring, the cover cylinder shell and the fixed outer ring. The pressing ring presses the cover cylinder shell so that it will not undergo significant circumferential deformation when it rubs against the choke gear ring.

[0036] In this embodiment, the movable inner ring and the choke gear ring are made of sulfuric acid dew point corrosion resistant steel (09CrCuSb), and the covering cylinder shell is made of brass. Sulfuric acid dew point corrosion resistant steel has good corrosion resistance, and brass has good corrosion resistance and good toughness. When there is friction with the rotating choke gear ring, it will not destroy itself nor damage the choke gear ring.

[0037] In the description of the present utility model, it should be noted that when terms such as "upper", "lower", "inner", "outer", "left", "right" and the like indicating orientation or positional relationship appear, it should be understood that the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the utility model product is usually placed when in use, or the orientation or positional relationship commonly understood by those skilled in the art, is only for the convenience of describing the present utility model and simplifying the description, and does not indicate or imply that the equipment or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, when terms such as "first" and "second" appear, they are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In the description of the present utility model, it should also be noted that, unless otherwise clearly specified and limited, terms such as "installation", "setting", and "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal connection of two elements. For those skilled in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

Claims

1. A sealing assembly used between an axial flow induced draft fan impeller and an inner cylinder of a casing, characterized in that: include: A movable bearing member, which is mounted on the impeller and can rotate with the impeller; A fixed bearing member, which is installed on the inner cylinder of the casing and corresponds to the position of the movable bearing member; A fixed cover component is installed on the fixed bearing component and is adapted to the shape of the movable bearing component. The fixed cover component covers the outside of the movable bearing component, and a gap is reserved between the fixed cover component and the movable bearing component so that the movable bearing component can rotate in the fixed cover component; A movable flow-blocking component is installed on the movable bearing component and cooperates with the fixed cover component. The movable flow-blocking component seals the gap between the fixed cover component and the movable bearing component, and blocks the process of external smoke entering the gap between the fixed cover component and the movable bearing component, so that its pressure is less than or equal to the pressure of the sealed airflow; The pressing and positioning component is installed on the fixed covering component and is engaged with the fixed bearing component. The fixed covering component is pressed and positioned on the fixed bearing component by the pressing and positioning component.

2. A sealing assembly for use between an axial flow induced draft fan impeller and an inner cylinder of a casing according to claim 1, characterized in that: The movable bearing components include: The movable inner ring is welded to the outer wall of the impeller, extends along the circumference of the impeller, and protrudes toward the inner cylinder of the casing.

3. A sealing assembly for use between an axial flow induced draft fan impeller and an inner cylinder of a casing according to claim 2, characterized in that: The fixed load-bearing member comprises: The fixed outer ring is welded to the outer wall of the inner cylinder of the casing, extends along the circumference of the impeller and protrudes toward the impeller, and its diameter is greater than the diameter of the movable inner ring.

4. A sealing assembly for use between an axial flow induced draft fan impeller and an inner cylinder of a casing according to claim 3, characterized in that: The fixed cover component comprises: The covering cylindrical shell is installed on the inner wall of the fixed outer ring, extends along the circumference of the impeller, protrudes toward the movable inner ring, and covers the outside of the movable inner ring, with a gap reserved between the covering cylindrical shell and the movable inner ring.

5. A sealing assembly for use between an axial flow induced draft fan impeller and an inner cylinder of a casing according to claim 4, characterized in that: The movable flow blocking member comprises: A choke gear ring is provided with a group, each choke gear ring is formed on the outer wall of the movable inner ring, extends along the circumference of the movable inner ring, protrudes radially toward the cover shell, and is arranged sequentially along the axial direction of the movable inner ring to form a choke recess between adjacent choke gear rings.

6. A sealing assembly for use between an axial flow induced draft fan impeller and an inner cylinder of a casing according to claim 4, characterized in that: The press-fit positioning component includes: A pressing ring, which is located on the inner wall of the cover cylinder shell and presses the cover cylinder shell between the fixed outer ring and the pressing ring; A group of positioning bolts are provided, and each positioning bolt is arranged in sequence along the circumference of the pressing ring, and penetrates the pressing ring, the covering cylinder shell and the fixed outer ring.

7. The sealing assembly for use between an axial flow induced draft fan impeller and an inner cylinder of a casing according to claim 5, characterized in that: The movable inner ring and the choke gear ring are made of sulfuric acid dew point corrosion resistant steel, and the cover cylinder shell is made of brass.

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