A coal-fired boiler induced draft fan impeller diameter expansion capacity increasing device

Abstract

The utility model relates to a kind of coal powder boiler induced draft fan impeller diameter increasing capacity device, and it is disclosed in the technical field of induced draft fan impeller machinery, including mounting plate, fixed support, control structure, power component and fan assembly, the support foot of mounting plate bottom has rubber pad, plays the role of supporting shock absorption, control structure contains control box, operating screen and cooling fan, can be intelligently adjusted and radiate heat, power component passes through motor, large and small pulley and V-shaped belt transmission power, the impeller of fan assembly rotates suction flue gas in shell, its beneficial effect lies in, optimization impeller structure and supporting component improve equipment reliability, streamline shell reduces airflow resistance, control structure and power component are cooperated to realize intelligent speed regulation, satisfy boiler increasing capacity and energy-saving demand, solve the problems such as insufficient strength, low efficiency and poor automation in traditional technology.

Description

Technical Field

[0001] This utility model relates to the field of induced draft fan impeller mechanics, specifically a device for expanding the diameter and increasing the capacity of an induced draft fan impeller for a pulverized coal boiler. Background Technology

[0002] In thermal power generation systems, pulverized coal boilers release heat energy by burning pulverized coal to drive steam turbines for power generation. The induced draft fan, as a key auxiliary machine of the boiler, has the core function of exhausting the flue gas generated during combustion in the furnace, maintaining negative pressure in the furnace, and ensuring stable combustion. With the power industry's increasingly urgent need for improved unit efficiency and capacity expansion, optimizing the performance of induced draft fans has become crucial. When boiler load increases or flue gas treatment requirements rise, existing induced draft fans often suffer from insufficient airflow and pressure, leading to decreased combustion efficiency and even affecting the unit's load-carrying capacity. Therefore, it is necessary to improve the flue gas extraction capacity of induced draft fans through technologies such as impeller diameter expansion to meet the high-efficiency operation requirements of boiler systems.

[0003] Traditional induced draft fan impeller capacity expansion technology has significant limitations. On the one hand, simply increasing the impeller diameter can easily lead to insufficient blade strength, which may cause vibration or fatigue damage during high-speed rotation. Moreover, the load-bearing capacity of the original bearings, shafts, and other components is difficult to match the expanded impeller, increasing the risk of equipment failure. On the other hand, traditional retrofits do not systematically optimize the fluid dynamics design. After the impeller is enlarged, problems such as airflow turbulence and increased eddy current losses often occur, leading to decreased fan efficiency, increased energy consumption, and even excessive noise affecting the on-site operating environment. In addition, traditional devices lack linkage design with the automated control system and cannot adjust the induced draft parameters in real time according to the boiler load, further restricting the actual effect of capacity expansion retrofits and making it difficult to meet the intelligent and energy-saving operation requirements of modern power plants. Therefore, we propose a pulverized coal boiler induced draft fan impeller diameter expansion and capacity expansion device. Utility Model Content

[0004] To address the shortcomings of existing technologies, this utility model provides a device for expanding the diameter and increasing the capacity of the impeller of a pulverized coal boiler induced draft fan, thus solving the aforementioned problems.

[0005] To achieve the above-mentioned objectives, this utility model provides the following technical solution: a device for expanding the diameter and increasing the capacity of an induced draft fan impeller in a pulverized coal boiler, comprising:

[0006] The mounting plate and the mounting bracket are provided with two sets of parallel support feet at the bottom of the mounting plate and rubber pads at the bottom of the support feet; a mounting bracket is provided on one side of the top of the mounting plate, a motor mounting bracket is provided on one side of the mounting bracket, a motor is provided on the top of the motor mounting bracket, and a fan housing is provided on the side of the mounting bracket.

[0007] The control structure is located on the top of the mounting plate, near the corner and next to the side of the fixing frame. The control structure includes a control box, which contains an intelligent controller that can receive boiler load signals. The intelligent controller is connected to a motor signal and is used to adjust the motor speed according to the boiler load signal.

[0008] A power assembly is disposed on the top of the motor mounting bracket. The power assembly includes a motor structure and a connection structure, and the connection structure is disposed on the side of the motor structure.

[0009] The fan assembly is located on the top of the motor mounting bracket. The fan assembly includes an impeller structure and a housing structure. The housing structure is located on the side of the mounting bracket, and the impeller structure is located inside the housing structure.

[0010] The impeller structure includes a set of bearing seats, a rotating shaft, and an impeller that are symmetrically distributed on an axis. The bearing seats are fixedly installed on the top of the motor mounting bracket, and the rotating shaft is rotatably assembled inside the bearing seats. The impeller is fixed at the end of the rotating shaft. The outer shell structure includes a fan shell. The inner wall of the fan shell is streamlined to fit the profile of the impeller. The fan shell has a fan inlet with a square groove structure.

[0011] Preferably, a square groove is provided on one side of the top of the mounting plate, a fixing bracket is fixedly installed on the top side of the mounting plate, and a motor mounting bracket is fixedly installed on the side of the fixing bracket.

[0012] Preferably, the control structure includes a control box, an operation panel, and a cooling fan. The control box is fixedly installed in a square groove on the top of the mounting plate. The operation panel is fixedly installed on the outer side wall of the control box. Both side walls of the control box have through square grooves, and a set of axially symmetrical cooling fans are fixedly installed in the square grooves.

[0013] Preferably, the motor structure includes a motor mounting plate and a motor, with the motor mounting plate fixedly mounted on the top of the motor mounting bracket, and the motor fixedly mounted on the top of the motor mounting plate.

[0014] Preferably, the connection structure includes a large pulley, a small pulley, and a V-belt. The large pulley is fixedly installed at the end of the output shaft of the motor, the outer surface of the large pulley is fixedly connected to the V-belt, and the inner side of the other end of the V-belt is fixedly connected to the small pulley.

[0015] Preferably, the outer casing structure includes a fan casing, an impeller casing, and a fan outlet. The fan casing is fixedly installed on the side of the fixed frame. The fan casing is located on the inner and outer sides of the impeller. A circular hole is provided on the other end of the fan casing corresponding to the end where the rotating shaft is installed. The impeller casing is fixedly installed in the circular hole on the side of the fan casing. A square groove is provided on the other side of the fan casing. The fan outlet is fixedly connected to the side of the square groove on the side of the fan casing.

[0016] Compared with the prior art, this utility model provides a device for expanding the diameter and increasing the capacity of the impeller of a pulverized coal boiler induced draft fan, which has the following beneficial effects:

[0017] This pulverized coal boiler induced draft fan impeller diameter expansion and capacity increase device significantly improves the reliability of equipment operation through optimized impeller structure design and upgraded supporting components. The impeller is manufactured using high-strength materials, and the axially symmetrical distribution design of the bearing housing and shaft enhances the dynamic balance performance during impeller rotation, avoiding vibration or fatigue damage caused by uneven load after traditional diameter expansion. Simultaneously, the rubber pad design at the bottom of the support feet reduces vibration transmission during equipment operation, further reducing the wear risk of critical components such as bearings and shafts. The matching design of the outer shell structure and impeller creates a smooth flue gas flow path, reducing airflow resistance and energy loss. The streamlined design of the inner side of the fan casing, combined with the square groove structure design of the fan inlet, makes the flue gas velocity distribution more uniform and reduces turbulence effects. Through the coordinated design of the control structure and power components, the impeller speed can be adjusted in real time according to the boiler load. The intelligent controller in the control box receives boiler signals and dynamically matches the flue gas emission requirements by adjusting the motor speed and belt drive ratio. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this utility model;

[0019] Figure 2 This is a schematic diagram of the bearing housing of this utility model;

[0020] Figure 3 This is a schematic diagram of the impeller of this utility model;

[0021] Figure 4 This is a schematic diagram of the rotating shaft of this utility model.

[0022] In the diagram: 1. Mounting plate; 2. Support foot; 3. Control box; 4. Operation panel; 5. Cooling fan; 6. Fixture; 7. Motor mounting bracket; 8. Motor mounting plate; 9. Motor; 10. Large pulley; 11. Bearing housing; 12. Shaft; 13. Small pulley; 14. V-belt; 15. Impeller; 16. Fan casing; 17. Impeller casing; 18. Fan outlet. Detailed Implementation

[0023] 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 some embodiments 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.

[0024] Please see Figure 1-4 A device for expanding the diameter and increasing the capacity of an induced draft fan impeller in a pulverized coal boiler includes:

[0025] Mounting plate 1 and fixing frame 6, the bottom of mounting plate 1 is provided with two sets of parallel support feet 2, the bottom of the support feet 2 is provided with rubber pads; the top side of mounting plate 1 is provided with fixing frame 6, the side of fixing frame 6 is provided with motor mounting frame 7, the top of motor mounting frame 7 is provided with motor 9, and the side of fixing frame 6 is provided with fan housing 16.

[0026] The control structure is located on the top of the mounting plate 1 near the corner and next to the side of the fixing frame 6. The control structure includes a control box 3, which contains an intelligent controller that can receive boiler load signals. The intelligent controller is connected to the motor 9 and is used to adjust the motor speed according to the boiler load signal.

[0027] A power assembly is disposed on the top of the motor mounting bracket 7. The power assembly includes a motor structure and a connection structure, and the connection structure is disposed on the side of the motor structure.

[0028] The fan assembly is located on the top of the motor mounting bracket 7. The fan assembly includes an impeller structure and a housing structure. The housing structure is located on the side of the fixing bracket 6, and the impeller structure is located inside the housing structure.

[0029] The impeller structure includes a set of axisymmetrically distributed bearing housings 11, rotating shafts 12, and impellers 15. The bearing housings 11 are fixedly installed on the top of the motor mounting bracket 7. The rotating shafts 12 are rotatably assembled inside the bearing housings 11, and the impellers 15 are fixed at the ends of the rotating shafts 12. The bearing housings 11 are made of double-row radial ball bearings. The blades of the impellers 15 are made of wear-resistant cast iron and coated with an anti-wear coating to resist the erosion and wear of dust particles in the flue gas. The impellers 15 undergo dynamic balancing tests before leaving the factory, and the counterweights are precisely welded to the counterweight positions of the blades to ensure that the eccentricity during rotation is within a suitable range and to prevent severe vibration caused by dynamic balancing failure.

[0030] The outer casing structure includes a fan casing 16, the inner wall of which is adapted to the impeller profile and is streamlined, and the fan casing 16 is provided with a fan port 18 with a square groove structure.

[0031] Furthermore, a square groove is provided on one side of the top of the mounting plate 1, and a fixing frame 6 is fixedly installed on the top side of the mounting plate 1. A motor mounting frame 7 is fixedly installed on the side of the fixing frame 6. In addition to supporting the main body of the device, the two sets of parallel support feet 2 at the bottom of the mounting plate 1 have rubber pads at the bottom that can absorb the vibration energy during the operation of the equipment through elastic deformation, reduce the transmission of vibration to the foundation, and at the same time avoid the noise generated by the direct rigid contact between the mounting plate 1 and the ground. The square groove provided on the top of the mounting plate 1 is used to fix the control box 3, ensuring the installation stability of components such as the fixing frame 6 and the motor mounting frame 7, and avoiding structural deformation caused by uneven force.

[0032] Furthermore, the control structure includes a control box 3, an operation panel 4, and cooling fans 5. The control box 3 is fixedly installed in the square groove opened on the top of the mounting plate 1. The operation panel 4 is fixedly installed on the side wall of the control box 3 facing outward. Both side walls of the control box 3 have through square grooves, and a set of axisymmetric cooling fans 5 are fixedly installed in the square grooves. The cooling fans 5 on both sides of the control box 3 form a convection heat dissipation channel through the axisymmetric layout. When the electronic components in the control box 3 generate heat, the cooling fans 5 actively draw in the outside cold air, and after internal heat exchange, discharge the hot air, keeping the temperature inside the box below a suitable temperature to prevent the controller from malfunctioning due to high temperature. The operation panel 4 adopts a touch screen design, which supports real-time display of operating parameters such as motor speed, air volume, and air pressure. At the same time, it allows the operator to manually input load adjustment commands, realizing the dual mode switching of automatic control and manual intervention.

[0033] Furthermore, the motor structure includes a motor mounting plate 8 and a motor 9. The motor mounting plate 8 is fixedly mounted on the top of the motor mounting bracket 7, and the motor 9 is fixedly mounted on the top of the motor mounting plate 8. The motor mounting plate 8 is fixed to the top of the motor mounting bracket 7 by bolts. Its surface is treated with anti-rust to resist the corrosion of the humid flue gas environment in the boiler room. A shock-absorbing pad is set between the motor mounting plate 8 and the motor 9 to further reduce the vibration transmission during motor operation and extend the bearing life of the motor 9. In addition, the wiring port of the motor 9 is equipped with a waterproof sealing cover to prevent circuit failure caused by dust and moisture intrusion.

[0034] Furthermore, the connection structure includes a large pulley 10, a small pulley 13, and a V-belt 14. The large pulley 10 is fixedly installed at the end of the output shaft of the motor 9. The V-belt 14 is fixedly connected to the outer surface of the large pulley 10, and the small pulley 13 is fixedly connected to the inner side of the other end of the V-belt 14. The groove surfaces of both the large pulley 10 and the small pulley 13 are treated with anti-slip material. The V-belt 14 is made of neoprene rubber, which has wear-resistant and anti-aging properties. When the device is running, the V-belt 14 transmits the rotational power of the large pulley 10 to the small pulley 13 through tension. Since the diameter of the large pulley 10 is larger than that of the small pulley 13, a speed-increasing transmission ratio is formed, allowing the impeller 15 to obtain a higher rotational speed. At the same time, the motor mounting bracket 7 is equipped with a tension adjustment bolt, which can periodically adjust the tension of the V-belt 14 to avoid belt slippage caused by long-term use.

[0035] Furthermore, the outer casing structure includes a fan casing 16, an impeller casing 17, and a fan outlet 18. The fan casing 16 is fixedly installed on the side of the mounting bracket 6. The fan casing 16 is located on the inner and outer sides of the impeller 15. A round hole is opened at the other end of the fan casing 16 corresponding to the mounting of the rotating shaft 12. The impeller casing 17 is fixedly installed in the round hole on the side of the fan casing 16. A square groove is opened on the other side of the fan casing 16. The fan outlet 18 is fixedly connected to the side of the square groove on the side of the fan casing 16. The connection between the fan casing 16 and the mounting bracket 6 adopts a flange sealing design and is equipped with a high-temperature resistant sealing ring to prevent flue gas leakage. The inner wall of the impeller casing 17 adopts a smooth curved surface design and maintains a uniform gap with the outer contour of the impeller 15. The square groove structure of the fan outlet 18 is connected to the boiler flue through a gradually expanding pipe, making the transition of flue gas from the impeller outlet to the flue smoother. The outer wall of the fan casing 16 is covered with sound insulation cotton. Combined with the shock absorption design of the support foot 2, the operating noise of the device is controlled below the standard.

[0036] Structural Description:

[0037] Mounting plate 1: Mounting plate 1 is the basic support structure of the device. A fixing frame 6 is set on one side of the top, a square groove is opened on one side of the top, and two sets of parallel support feet 2 are fixedly installed at the bottom.

[0038] Support leg 2: Support leg 2 is fixedly installed on the bottom of mounting plate 1. Each set of support legs 2 has a rubber pad fixedly installed on the bottom, which serves as a support device and shock absorber.

[0039] Control box 3: The control box 3 is installed in the square groove opened on the top of the mounting plate 1. The operation panel 4 is fixedly installed on the side wall facing outward. Both side walls are provided with through square grooves. A set of axially symmetrical cooling fans 5 are fixedly installed in the square grooves.

[0040] Operation panel 4: Operation panel 4 is fixedly installed on the side wall of the control box 3 facing outward, and is used to input control commands and display the operating status of the equipment;

[0041] Cooling fan 5: The cooling fan 5 is installed in the square slots on both sides of the control box 3 and is distributed symmetrically on the axis. It is used to dissipate heat from the electronic components inside the control box 3.

[0042] Fixing bracket 6: Fixing bracket 6 is installed on the top side of mounting plate 1, and motor mounting bracket 7 and fan housing 16 are fixedly installed on the side to provide support;

[0043] Motor mounting bracket 7: The motor mounting bracket 7 is fixedly installed on the side of the fixed bracket 6. The top is used to install the motor structure, and the side is used to install the connecting structure.

[0044] Motor mounting plate 8: The motor mounting plate 8 is fixedly installed on the top of the motor mounting bracket 7. The surface is treated with rust prevention, and the motor 9 is fixedly installed on the top.

[0045] Motor 9: Motor 9 is mounted on the top of motor mounting plate 8, and a large pulley 10 is fixedly mounted at the end of the output shaft to provide power to the device;

[0046] Large pulley 10: The large pulley 10 is fixedly installed at the end of the output shaft of the motor 9, and its outer surface is connected to the small pulley 13 through the V-belt 14;

[0047] Bearing housing 11: The bearing housing 11 is fixedly installed on the top of the motor mounting bracket 7, and is distributed symmetrically on the axis. The rotating shaft 12 is rotatably installed inside it.

[0048] Rotary shaft 12: Rotary shaft 12 is rotatably mounted in bearing housing 11, and an impeller 15 is fixedly mounted on one side of one end for transmitting rotational power;

[0049] Small pulley 13: The small pulley 13 is mounted on the rotating shaft 12 and is connected to the large pulley 10 through the V-belt 14 to transmit power;

[0050] V-belt 14: V-belt 14 connects the large pulley 10 and the small pulley 13 and is used to transmit rotational power;

[0051] Impeller 15: Impeller 15 is fixedly installed at one end of the rotating shaft 12 and rotates at high speed inside the fan housing 16 to draw in smoke.

[0052] Fan housing 16: The fan housing 16 is fixedly installed on the side of the fixed frame 6, and the impeller housing 17 and impeller 15 are installed inside to guide the direction of flue gas flow;

[0053] Impeller housing 17: The impeller housing 17 is fixedly installed in the round hole on the side of the fan housing 16, located on the inner and outer sides of the impeller 15, and is used to guide the flue gas;

[0054] Fan outlet 18: Fan outlet 18 is fixedly installed in the square groove on the other side of the fan housing 16 and connected to the boiler flue to discharge flue gas;

[0055] Working Principle: When the device is started, motor 9 begins to run. Motor 9 is fixed to motor mounting bracket 7 via motor mounting plate 8. The output shaft of motor 9 drives large pulley 10 to rotate. Large pulley 10 is connected to small pulley 13 via V-belt 14, thus transmitting power to small pulley 13. Small pulley 13 is mounted on rotating shaft 12, which in turn drives rotating shaft 12 to rotate. Both ends of rotating shaft 12 are fixed to motor mounting bracket 7 via bearing seats 11. Impeller 15 is mounted on one end of rotating shaft 12. Therefore, the rotation of rotating shaft 12 will drive impeller 15 to rotate at high speed inside fan housing 16. When impeller 15 rotates, centrifugal force is used to throw flue gas outward from the center of impeller. Flue gas first enters impeller housing 17, and then is discharged through fan port 18 on the side of fan housing 16. In this process, the fan housing 16 and impeller housing 17 of the housing structure provide a closed space for the rotation of impeller 15, and guide the flow path of flue gas to ensure smooth flue gas flow. The control box 3 in the control structure is installed in the square groove on the top of the mounting plate 1. The operation screen 4 on the control box 3 is used to input control commands and display the operating status of the equipment. The intelligent controller in the control box 3 can receive signals from the boiler system and automatically adjust the speed of the motor 9 according to the changes in boiler load. For example, when the boiler load increases, the control box 3 issues a command to increase the speed of the motor 9. Through the transmission ratio adjustment of the large pulley 10 and the small pulley 13, the speed of the impeller 15 is increased, thereby increasing the amount of flue gas drawn in. When the boiler load decreases, the control box 3 reduces the speed of the motor 9 and reduces the amount of flue gas drawn in, so as to achieve the purpose of dynamically matching the flue gas emission requirements. The cooling fan 5 is installed on both side walls of the control box 3 to dissipate heat from the electronic components inside the control box 3 and ensure the stable operation of the control structure. The support feet 2 and rubber pads at the bottom of the mounting plate 1 play a supporting and shock-absorbing role, reducing the vibration during the operation of the device and improving the stability of the equipment.

[0056] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for expanding the diameter and increasing the capacity of an induced draft fan impeller in a pulverized coal boiler, characterized in that, include: The mounting plate (1) and the fixing frame (6) are provided. The bottom of the mounting plate (1) is provided with two sets of parallel support feet (2) and the bottom of the support feet (2) is provided with rubber pads. The top side of the mounting plate (1) is provided with a fixing frame (6), the side of the fixing frame (6) is provided with a motor mounting frame (7), the top of the motor mounting frame (7) is provided with a motor (9), and the side of the fixing frame (6) is provided with a fan housing (16). The control structure is located on the top of the mounting plate (1), near the corner of the top of the mounting plate (1) and next to the side of the fixing frame (6); the control structure includes a control box (3), which is equipped with an intelligent controller that can receive boiler load signals. The intelligent controller is connected to the motor (9) and is used to adjust the motor speed according to the boiler load signal. A power assembly is disposed on the top of the motor mounting bracket (7), the power assembly including a motor structure and a connection structure, the connection structure being disposed on the side of the motor structure; The fan assembly is located on the top of the motor mounting bracket (7). The fan assembly includes an impeller structure and a housing structure. The housing structure is located on the side of the fixing bracket (6). The impeller structure is located inside the housing structure. The impeller structure includes a set of bearing seats (11), a rotating shaft (12), and an impeller (15) that are symmetrically distributed. The bearing seats (11) are fixedly installed on the top of the motor mounting bracket (7), and the rotating shaft (12) is rotatably assembled inside the bearing seats (11). The impeller (15) is fixed at the end of the rotating shaft (12). The outer casing structure includes a fan casing (16), the inner wall of the fan casing (16) is adapted to the impeller profile and is streamlined, and the fan casing (16) is provided with a fan port (18) with a square groove structure.

2. The device for expanding the diameter and increasing the capacity of the induced draft fan impeller in a pulverized coal boiler according to claim 1, characterized in that, A square groove is provided on one side of the top of the mounting plate (1), and a fixing bracket (6) is fixedly installed on the top side of the mounting plate (1). A motor mounting bracket (7) is fixedly installed on the side of the fixing bracket (6).

3. The device for expanding the diameter and increasing the capacity of the impeller of a pulverized coal boiler induced draft fan according to claim 2, characterized in that, The control structure includes a control box (3), an operation screen (4), and a cooling fan (5). The control box (3) is fixedly installed in the square groove opened at the top of the mounting plate (1). The operation screen (4) is fixedly installed on the side wall of the control box (3) facing outward. Both sides of the control box (3) are provided with through square grooves. A set of axially symmetrical cooling fans (5) is fixedly installed in the square grooves.

4. The device for expanding the diameter and increasing the capacity of the impeller of a pulverized coal boiler induced draft fan according to claim 2, characterized in that, The motor structure includes a motor mounting plate (8) and a motor (9). The motor mounting plate (8) is fixedly mounted on the top of the motor mounting bracket (7), and the motor (9) is fixedly mounted on the top of the motor mounting plate (8).

5. The device for expanding the diameter and increasing the capacity of the impeller of a pulverized coal boiler induced draft fan according to claim 4, characterized in that, The connection structure includes a large pulley (10), a small pulley (13), and a V-belt (14). The large pulley (10) is fixedly installed at the end of the output shaft of the motor (9). The V-belt (14) is fixedly connected to the outer surface of the large pulley (10), and the small pulley (13) is fixedly connected to the inner side of the other end of the V-belt (14).

6. The device for expanding the diameter and increasing the capacity of the induced draft fan impeller in a pulverized coal boiler according to claim 1, characterized in that, The outer casing structure also includes an impeller casing (17). The fan casing (16) is fixedly installed on the side of the fixed frame (6). The fan casing (16) is located on the inner and outer sides of the impeller (15). The fan casing (16) has a round hole at the other end corresponding to the shaft (12) on which it is installed. The impeller casing (17) is fixedly installed in the round hole on the side of the fan casing (16). A square groove is provided on the other side of the fan casing (16).

Images