A fan unit for a coal milling unit

Abstract

The present disclosure relates to a fan unit for a coal grinding unit, comprising a fan, a motor and a stuffing box. Wherein the fan comprises a fan shell and a fan impeller contained in the fan shell, an air inlet and an air outlet are arranged on the fan shell, the motor is connected with a motor shaft, the end of the motor shaft away from the motor penetrates into the fan shell and is coaxially connected with the fan impeller, the stuffing box is sleeved outside the motor shaft and fixed on the fan shell, a labyrinth seal and a packing seal are arranged at both ends of the stuffing box respectively, the labyrinth seal is located on the side close to the fan shell, and the packing seal is located on the side away from the fan shell. The fan unit for the coal grinding unit provided by the present disclosure prevents the leakage of the sealing medium by setting the double sealing of the labyrinth seal and the packing seal, improves the sealing performance of the fan, prolongs the service life of the equipment, and improves the safety during the operation of the whole fan.

Description

Technical Field

[0001] This disclosure relates to the field of mechanical equipment technology, and more specifically, to a fan unit for a coal grinding unit. Background Technology

[0002] Fans are indispensable equipment in the industrial field. They convert mechanical energy into the kinetic and pressure energy of gas through the rotation of the impeller, enabling gas transportation and pressurization. However, existing fan designs suffer from poor sealing performance at the connection between the casing and the motor shaft. This not only leads to leakage of the sealing medium, causing resource waste and environmental pollution, but also causes the leaked medium to accumulate around the fan, creating safety hazards, especially the risk of asphyxiation. Furthermore, media leakage is accompanied by loud noise, worsening the working environment. Utility Model Content

[0003] In view of this, the present disclosure provides a blower unit for a coal grinding unit to address the technical deficiencies in the prior art.

[0004] To achieve the above objectives, the present disclosure adopts the following technical solution: This disclosure provides a blower unit for a coal milling unit, comprising: A fan, the fan including a fan casing and a fan impeller housed in the fan casing, and an air inlet and an air outlet are provided on the fan casing; An electric motor is provided, wherein the motor is connected to a motor shaft, and one end of the motor shaft away from the motor passes through the fan casing and is coaxially connected to the fan impeller. A stuffing box is fitted around the outside of the motor shaft and fixed to the fan housing. A labyrinth seal and a packing seal are respectively provided at both ends of the stuffing box. The labyrinth seal is located on the side adjacent to the fan housing, and the packing seal is located on the side away from the fan housing.

[0005] In one embodiment of this disclosure, the air inlet is disposed on the end face of the fan housing and on the side opposite to the motor shaft, and the air outlet is located on the fan housing and in the radial direction of the fan impeller.

[0006] In one embodiment of this disclosure, a packing gland is provided at one end of the packing seal near the motor. The packing gland is fixed to the stuffing box by bolts and is configured to press the packing of the packing seal into the inner cavity of the stuffing box.

[0007] In one embodiment of this disclosure, the stuffing box is detachably fixed to the fan housing by bolts.

[0008] In one embodiment of this disclosure, the packing material for the packing seal is graphite packing.

[0009] In one embodiment of this disclosure, the labyrinth seal is a plurality of annular toothed groove structures arranged sequentially around the motor shaft.

[0010] In one embodiment of this disclosure, the fan unit further includes an air inlet pipe and an air outlet pipe, the air inlet pipe being connected to the air inlet and the air outlet pipe being connected to the air outlet.

[0011] In one embodiment of this disclosure, the inner wall of the fan housing is provided with a wear-resistant layer, which is made of ceramic material, hard alloy or stainless steel.

[0012] In one embodiment of this disclosure, the inner wall of the fan housing is provided with a guide groove, which is configured to guide the airflow smoothly.

[0013] In one embodiment of this disclosure, a filter device is provided at the air inlet, the filter device being configured to filter impurities in the sealing medium.

[0014] The fan unit for coal grinding units provided in this disclosure prevents leakage of the sealing medium by setting up a double seal of labyrinth seal and packing seal, thereby improving the sealing performance of the fan, extending the service life of the equipment, and improving the safety of the entire fan operation process.

[0015] Other features and advantages of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a fan unit for a coal milling unit according to an embodiment of the present disclosure; Figure 2 This is a schematic diagram of the structure of a fan unit for a coal mill unit provided in another embodiment of this disclosure; Figure 3 yes Figure 2 Cross-sectional view along the AA direction.

[0017] 1-Fan; 11-Fan housing; 111-Air inlet; 112-Air outlet; 12-Fan impeller; 2-Motor; 3-Motor shaft; 4-Stuffing box; 41-Labyrinth seal; 42-Stuffing seal; 421-Stuffing gland. Detailed Implementation

[0018] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present disclosure.

[0019] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use.

[0020] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0021] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0022] The specific embodiments of this disclosure are described below with reference to the accompanying drawings.

[0023] In this article, terms such as "up," "down," "front," "back," "left," and "right" are used only to indicate the relative positional relationship between related parts, rather than to define the absolute position of these related parts.

[0024] In this article, "first," "second," etc., are used only to distinguish one another, and not to indicate degree of importance, order, or prerequisite for each other.

[0025] In this document, terms such as “equal” and “same” are not strict mathematical and / or geometric limitations, but also include errors that are understandable to those skilled in the art and permissible in manufacturing or use.

[0026] This disclosure provides a blower unit for a coal pulverizing unit, including a blower, a motor, and a stuffing box. The blower includes a blower casing and a blower impeller housed within the casing. An air inlet and an air outlet are provided on the blower casing. The motor is connected to a motor shaft, with one end of the motor shaft, away from the motor, passing through the blower casing and coaxially connected to the blower impeller. The stuffing box is fitted around the outside of the motor shaft and fixed to the blower casing. A labyrinth seal and a packing seal are respectively provided at both ends of the stuffing box, with the labyrinth seal located on the side adjacent to the blower casing and the packing seal located on the side away from the blower casing.

[0027] The fan unit for coal grinding units provided in this disclosure prevents leakage of the sealing medium by setting up a double seal of labyrinth seal and packing seal, thereby improving the sealing performance of the fan, extending the service life of the equipment, and improving the safety of the entire fan operation process.

[0028] For ease of understanding, please refer to the following: Figures 1 to 3 The specific structure and working principle of the blower unit for a coal mill unit disclosed herein will be described in detail with reference to one embodiment.

[0029] like Figure 1As shown, the blower unit for a coal pulverizing unit provided in this disclosure includes a blower 1, a motor 2, and a stuffing box 4. A motor shaft 3 is connected to the motor 2, and the motor 2 is connected to the blower 1 through the motor shaft 3. Specifically, the blower 1 includes a blower housing 11 and a blower impeller 12 housed in the blower housing 11. The end of the motor shaft 3 away from the motor 2 passes through the blower housing 11 and is coaxially connected to the blower impeller 12, so that the motor 2 provides power to the blower impeller 12, enabling the blower impeller 12 to rotate at high speed to meet the operating requirements of the coal pulverizing unit.

[0030] An air inlet 111 and an air outlet 112 are provided on the blower housing 11. The air inlet 111 and the air outlet 112 are configured for the inflow and outflow of the sealing medium. In this embodiment, nitrogen is selected as the sealing medium. Nitrogen, as an inert gas, can effectively isolate oxygen and prevent coal powder from oxidizing at high temperatures. A stuffing box 4 is sleeved on the outside of the motor shaft 3. The stuffing box 4 is fixed to the blower housing 11 and is configured for sealing. A labyrinth seal 41 and a packing seal 42 are respectively provided at both ends of the stuffing box 4. The labyrinth seal 41 is located on the side adjacent to the blower housing 11, and the packing seal 42 is located on the side of the raw material blower housing 11.

[0031] During the operation of the blower 1, the sealing medium enters the blower 1 through the inlet 111, is pressurized by the blower impeller 12, and then exits through the outlet 112. During this process, the sealing medium leaks outwards along the shaft surface from the point where the blower 1 and the stuffing box 4 are located. When the sealing medium passes through the labyrinth seal 41, a throttling effect occurs in the gap of the labyrinth seal 41, thus achieving the purpose of preventing leakage. After passing through the labyrinth seal 41, a small amount of leaked sealing medium may still remain. Therefore, the packing seal 42, located downstream of the labyrinth seal 41, can further prevent leakage of the sealing medium, thereby achieving a complete seal. The blower unit provided in this disclosure not only ensures the efficient operation of the blower unit in the coal milling unit, but also extends the service life of the equipment, reduces maintenance costs, and improves production safety and environmental standards through the double protection of the labyrinth seal 41 and the packing seal 42.

[0032] like Figures 2 to 3 As shown, in one embodiment of this disclosure, the stuffing box 4 is detachably fixed to the fan housing 11 by bolts.

[0033] Specifically, multiple bolts are evenly arranged on the stuffing box 4 to detachably fix the stuffing box 4 to the fan housing 11. In this embodiment, four bolts are preferably used to fix the stuffing box 4. When maintenance or replacement of the packing seal 42 is required, it is not necessary to disassemble the entire fan 1 or motor 2; only the stuffing box 4 needs to be removed with bolts, which simplifies the maintenance process and saves time and labor costs. In addition, the bolt fixing ensures that there is an appropriate preload between the stuffing box 4 and the fan housing 11, thereby further optimizing the sealing effect and preventing leakage of the sealing medium. In daily operation, operators can also check the sealing status by disassembling the stuffing box 4, such as checking whether the packing is worn or damaged. This helps to detect potential problems in time and prevent failures.

[0034] In one embodiment of this disclosure, the labyrinth seal 41 is a plurality of annular toothed groove structures arranged sequentially around the motor shaft 3.

[0035] Specifically, when the sealing medium (e.g., nitrogen) attempts to pass through the gap between the motor shaft 3 and the fan housing 11, it first encounters a toothed groove. Due to the presence of the groove, the sealing medium is forced through a series of extremely narrow channels, the cross-sectional area of ​​which is much smaller than the normal gap between the shaft and the housing. In this situation, the flow velocity of the medium increases sharply, while the pressure decreases accordingly, i.e., a throttling effect occurs.

[0036] Subsequently, as the sealing medium passes through one groove and enters the next larger space, its flow velocity slows down and the pressure begins to recover. However, the same process repeats as it approaches the next groove, resulting in continuous energy consumption of the medium. This cyclical throttling and pressure recovery process not only reduces the average pressure of the sealing medium but also creates eddies and turbulence, further hindering the straight flow of the sealing medium and thus reducing the possibility of leakage. Furthermore, under normal operating conditions, there is no direct physical contact between the groove and the motor shaft 3, therefore there is no wear issue, ensuring the long-term stability and reliability of the seal while also reducing maintenance costs by eliminating the need for frequent replacement of worn parts.

[0037] like Figures 2 to 3 As shown, in one embodiment of this disclosure, a packing gland 421 is provided at one end of the packing seal 42 near the motor 2. The packing gland 421 is fixed to the stuffing box 4 by bolts and is configured to press the packing of the packing seal 42 into the inner cavity of the stuffing box 4.

[0038] Specifically, a packing gland 421 is provided at the end of the packing seal 42 near the motor 2. This is to ensure that the packing is stably positioned within the inner cavity of the stuffing box 4 and performs its sealing function. The packing gland 421 is fixed to the stuffing box 4 by multiple bolts. The bolts are evenly distributed on the packing gland 421, which not only fixes the packing gland 421 but also presses the packing tightly into the stuffing box 4 through its tightening force, forming a sealing interface. One end of the packing seal 42 abuts against the outermost toothed end face of the labyrinth seal 41. The toothed structure of the labyrinth seal 41 not only effectively reduces the leakage of the sealing medium but also serves as a positioning reference for the packing, ensuring the correct axial position of the packing. In addition, fixing the packing gland 421 with bolts facilitates the replacement of the packing.

[0039] In one embodiment of this disclosure, the packing for the packing seal 42 is graphite packing.

[0040] Specifically, graphite materials can withstand temperatures exceeding 600°C, exhibiting good high-temperature resistance in coal mill applications. Graphite packing has excellent resistance to most acids, alkalis, and solvents, and is not easily corroded. Graphite packing is easily processed into various shapes and sizes, adaptable to different specifications of stuffing boxes 4 and shaft diameters, facilitating installation and replacement. In this embodiment, the graphite packing is compressed within the inner cavity of the stuffing box 4, and appropriate pressure is applied through the packing gland 421 to ensure a tight contact between the packing and the motor shaft 3, effectively preventing leakage of the sealing medium. The use of graphite packing not only extends the service life of the fan system and reduces maintenance frequency but also improves the overall efficiency and safety of the system.

[0041] In one embodiment of this disclosure, the fan unit further includes an air inlet duct and an air outlet duct, the air inlet duct being connected to an air inlet 111 and the air outlet duct being connected to an air outlet 112.

[0042] The air inlet duct is the channel in the fan unit responsible for introducing the sealing medium into the fan unit. The air inlet duct is connected to the air inlet 111 on the fan housing 11, ensuring that the medium can enter the fan unit smoothly and without obstruction. The air outlet duct is located at the other end of the fan unit and is connected to the air outlet 112 on the fan housing 11. Its function is to discharge the sealing medium after it has been pressurized by the fan 1. In one embodiment of this disclosure, the air inlet 111 is located on the end face of the fan housing 11, and on the side opposite to the motor shaft 3. The air outlet 112 is located on the fan housing 11 and in the radial direction of the fan impeller 12.

[0043] In one embodiment of this disclosure, a filter device is provided at the air inlet 111, the filter device being configured to filter impurities in the sealing medium.

[0044] Unfiltered impurities, once inside the fan unit, can wear down blades, bearings, and seals, leading to decreased fan unit efficiency and even malfunction. Therefore, a filter is installed at the air inlet 111. Specifically, the filter typically consists of one or more layers of filter media, such as fiber mesh, wire mesh, foam material, or filter membrane. When a sealing medium, such as nitrogen, passes through these filter media, impurities are trapped, while clean gas passes through and continues into the fan system. Removing impurities through the filter ensures smooth system operation and avoids unnecessary downtime and maintenance costs. Furthermore, in industrial environments such as coal milling units, the filter helps improve workplace air quality, reduces employee exposure to harmful particulate matter, and improves occupational health and safety standards.

[0045] In one embodiment of this disclosure, the inner wall of the fan housing 11 is provided with a wear-resistant layer, which is made of ceramic material, hard alloy or stainless steel.

[0046] Given that the gas in the coal grinding process typically carries a large amount of coal powder and other solid particles, these high-speed flowing materials can cause severe wear on the inner wall of the blower casing 11, thus affecting the performance and lifespan of the blower 1. Therefore, a wear-resistant layer is also provided on the inner wall of the blower casing 11. Ceramic materials have high hardness and good wear resistance, effectively resisting the erosion of particles in the high-speed airflow. Ceramic materials also have thermal stability, able to withstand the high-temperature environment during coal grinding unit operation, improving the wear resistance of the blower casing 11. Hard alloy is a composite material composed of hard compounds such as tungsten carbide and metal binders such as cobalt, possessing high hardness and wear resistance. The hard alloy coating can significantly enhance the wear resistance of the blower casing 11, suitable for working conditions with severe wear. Stainless steel has good wear resistance, good corrosion resistance, good machinability and toughness, and is easy to install and maintain. The wear-resistant layer on the inner wall of the blower casing 11 can significantly extend the service life of the blower 1, reduce maintenance costs and downtime caused by wear, thereby improving the overall system's production efficiency and economic benefits.

[0047] In one embodiment of this disclosure, a guide groove is provided on the inner wall of the fan housing 11, the guide groove being configured to guide the airflow smoothly.

[0048] Specifically, the inner wall of the fan casing 11 is provided with guide grooves to guide and control the airflow direction. When gas enters the fan casing 11 from the inlet 111, its flow path is often accompanied by rotation and turbulence, which not only increases the energy consumption of the fan 1, but may also cause noise and vibration, reducing the stability and service life of the equipment. By providing guide grooves on the inner wall of the fan casing 11, the smoothness of the airflow can be improved. The guide grooves are usually designed in a spiral or curved shape, which can guide the incoming airflow in a specific direction, reduce turbulence, and make the airflow more orderly and stable. When the airflow passes through the fan impeller 12, it can impact the blades at a more uniform speed and angle, thereby improving the efficiency of the fan 1, reducing energy consumption, and reducing noise and vibration levels.

[0049] Another function of the guide channel is to optimize airflow distribution. Inside the fan 1, the airflow distribution directly affects the impeller's efficiency and wear. The guide channel ensures that the airflow is evenly distributed within the casing, preventing excessive concentration or dispersion of airflow in localized areas, reducing unbalanced loads on the impeller, and thus extending the service life of the fan 1. Guided by the guide channel, the airflow within the fan casing 11 becomes more orderly and efficient, directly improving the overall performance of the fan 1. Smooth airflow not only reduces energy waste but also ensures stable operation of the fan 1 under various working conditions, improving the production efficiency and economy of the coal grinding unit.

[0050] The fan unit for a coal pulverizing unit provided in this disclosure, through the double sealing of a labyrinth seal 41 and a packing seal 42, prevents leakage of the sealing medium, improves the fan's sealing performance, extends the equipment's service life, and enhances the safety of the entire fan operation. Furthermore, the packing gland 4 is designed as a detachable structure. When maintenance or replacement of the packing seal 42 is required, it is not necessary to disassemble the entire fan 1 or motor 2; the packing gland 4 can simply be removed using bolts, simplifying the maintenance process and saving time and labor costs.

[0051] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this disclosure is not limited to the described order of actions, because according to this disclosure, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this disclosure.

[0052] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0053] The preferred embodiments disclosed above are merely illustrative of this disclosure. The optional embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this disclosure. These embodiments are selected and specifically described in this disclosure to better explain the principles and practical applications of this disclosure, thereby enabling those skilled in the art to better understand and utilize this disclosure. This disclosure is limited only by the claims and their full scope and equivalents.

Claims

1. A blower unit for a coal milling unit, characterized in that, include: The fan (1) includes a fan housing (11) and a fan impeller (12) housed in the fan housing (11). An air inlet (111) and an air outlet (112) are provided on the fan housing (11). An electric motor (2) is connected to a motor shaft (3). One end of the motor shaft (3) away from the electric motor (2) passes through the fan casing (11) and is coaxially connected with the fan impeller (12). A stuffing box (4) is fitted on the outside of the motor shaft (3) and fixed on the fan housing (11). A labyrinth seal (41) and a packing seal (42) are respectively provided at both ends of the stuffing box (4). The labyrinth seal (41) is located on the side adjacent to the fan housing (11), and the packing seal (42) is located on the side away from the fan housing (11).

2. The fan unit according to claim 1, characterized in that, The air inlet (111) is located on the end face of the fan housing (11) and on the side opposite to the motor shaft (3). The air outlet (112) is located on the fan housing (11) and in the radial direction of the fan impeller (12).

3. The fan unit according to claim 1, characterized in that, The packing seal (42) is provided with a packing gland (421) at one end near the motor (2). The packing gland (421) is fixed to the stuffing box (4) by bolts and is configured to press the packing of the packing seal (42) into the inner cavity of the stuffing box (4).

4. The fan unit according to claim 1, characterized in that, The stuffing box (4) is detachably fixed to the fan housing (11) by bolts.

5. The fan unit according to claim 1, characterized in that, The packing material for the packing seal (42) is graphite packing.

6. The fan unit according to claim 1, characterized in that, The labyrinth seal (41) is a plurality of annular toothed groove structures arranged sequentially around the motor shaft (3).

7. The fan unit according to claim 1, characterized in that, It also includes an air inlet pipe and an air outlet pipe, wherein the air inlet pipe is connected to the air inlet (111) and the air outlet pipe is connected to the air outlet (112).

8. The fan unit according to claim 1, characterized in that, The inner wall of the fan casing (11) is provided with a wear-resistant layer, which is made of ceramic material, hard alloy or stainless steel.

9. The fan unit according to claim 1, characterized in that, The inner wall of the fan casing (11) is provided with a flow guide groove, which is configured to guide the airflow smoothly.

10. The fan unit according to claim 1, characterized in that, A filter device is provided at the air inlet (111), which is configured to filter impurities in the sealing medium.

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