A new type of hollow shaft sealing device for coal mill outlet

Abstract

The utility model provides a novel coal mill outlet hollow shaft sealing device, including spiral pipe, outlet short circuit and outlet short circuit pipe, be provided with the sealing ring outside outlet short circuit pipe, the graphite packing is equipped on the right side of sealing ring, the right side of limit ring is fixed through gland and bolt and is connected, the sealing baffle ring is equipped outside sealing ring and can rotate cooperation with it, when using, the outlet short circuit is fixed in spiral pipe, the graphite packing is pressed by gland, realizes reliable sealing to outlet short circuit pipe, the device passes through the combination of sealing ring, sealing baffle ring and graphite packing, effectively reduces the leakage powder and the air leakage phenomenon at the clearance between outlet short circuit and spiral pipe, adopts the form that dynamic and static seal supplement each other, has promoted the sealing stability, the graphite packing is the scissoring strip structure, is convenient for installation and replacement, the gland can be designed as multistage structure to facilitate dismounting, has improved the sealing effect, is convenient for maintenance, has good practicality and popularization value.

Description

Technical Field

[0001] This utility model relates to the technical field of coal mill equipment, and in particular to a novel coal mill outlet hollow shaft sealing device. Background Technology

[0002] As a key piece of equipment in the boiler system of thermal power plants, the coal mill's outlet is usually connected to the conveying pipeline via a hollow shaft. During operation, a large amount of pulverized coal passes through the outlet channel at high speed with the airflow. If the sealing structure is not reasonable, pulverized coal can easily overflow from the gap between the outlet short-circuit and the spiral tube, not only wasting pulverized coal but also increasing the dust concentration around the equipment, affecting the operating environment and the health of personnel.

[0003] Existing coal mill outlet sealing devices mostly use a single graphite packing or stuffing seal. Although the structure is simple and the cost is low, the sealing effect is limited. Under long-term operation, the gaps are prone to increase due to erosion by coal dust and wear of components, leading to frequent coal dust and air leakage. At the same time, the maintenance and replacement of existing equipment is relatively complex, resulting in high equipment maintenance costs.

[0004] Another existing approach attempts to install sealing rings or retaining rings at the outlet, but these are mostly static sealing structures that cannot effectively adapt to the vibrations and shifts generated during coal mill operation. This leads to unstable sealing surface clearances and a tendency for dynamic seal failure. In such cases, sealing reliability is insufficient, especially under high-load conditions, resulting in high rates of powder and air leakage.

[0005] For example, patent number CN218094223U describes a sealing device for preventing foreign objects from entering the moving and stationary parts of a coal mill. It includes a moving ring (1), a stationary ring (2), and a sealing ring (3). The outer wall of the moving ring is fixedly connected to the inner wall of the hollow shaft (4) of the coal mill and rotates synchronously with the hollow shaft. The outer wall of the stationary ring is fixedly connected to the inner wall of the coal mill outlet hopper (5). One end of the sealing ring is fixedly connected to the stationary ring, and the other end overlaps with the moving ring to form a sealing structure. The moving ring, stationary ring, and sealing ring are circular ring structures with different diameters and widths. The distance between the outer edge of the moving ring and the edge of the coal mill outlet hopper is greater than 20mm. This utility model is applied in the field of thermal power generation. Although the above technical solution can solve the problem of insufficient sealing performance to a certain extent, the sealing structure of the static sealing part needs to be frequently replaced. Therefore, it is necessary to easily disassemble and install the part that needs to be replaced. However, the above technical solution cannot quickly achieve the replacement of the static sealing position. Furthermore, at the junction of the dynamic and static sealing structures, the static sealing structure cannot directly fit the dynamic sealing gap for sealing.

[0006] Based on the above problems, this utility model provides a novel hollow shaft sealing device for coal mill outlet that can take into account both dynamic and static sealing, has a stable and reliable structure, and is easy to install and maintain. Utility Model Content

[0007] The purpose of this utility model is to overcome the shortcomings of the existing technology and provide a new type of hollow shaft sealing device for coal mill outlet.

[0008] The purpose of this utility model is achieved as follows: A novel sealing device for the hollow shaft at the outlet of a coal mill includes a spiral tube (hollow shaft at the outlet of a coal mill). A sealing ring is fixedly installed on the inner side of the right end of the spiral tube. An outlet short connector is connected to the right end of the spiral tube. An outlet short pipe is connected to the lower end of the outlet short connector. A sealing ring is fixedly installed on the outer side of the outlet short pipe. A graphite packing is installed on the right side of the sealing ring. A limit ring is fixedly installed on the outer side of the right end of the spiral tube. A pressure cap is connected to the right side of the limit ring.

[0009] Furthermore, the inner side of the spiral tube on the left side of the sealing ring is provided with multiple spiral strips.

[0010] In this application, the spiral tube on the coal mill is located on the equipment. The spiral tube is existing technology on coal mill equipment. The outlet short pipe is then placed inside the spiral tube. At this time, the sealing ring is located on the outer side of the sealing ring, and there is a clearance fit between the sealing ring and the sealing ring. The outlet short pipe is then fixed (the outlet short pipe is fixed by external placement. The specific fixing method is not technically limited and depends on the workshop conditions, as long as it does not move or rotate). The graphite packing is then placed around the right side of the sealing ring and the sealing ring, so that the left side of the graphite packing is in contact with the sealing ring and the sealing ring. The gland is then fixed to the limiting ring with bolts to achieve a fixed seal. The lower left side of the gland is squeezed to seal the graphite packing.

[0011] The above-mentioned sealing method can prevent pulverized coal from overflowing directly through the outer side wall of the outlet short pipe and then through the inner or outer side of the graphite packing. By setting a sealing ring and a sealing retainer, the gap between the outlet short pipe and the spiral pipe is limited to the gap formed between the sealing ring and the sealing retainer, and the right side of this gap is filled and contacted by the left side of the graphite packing, which greatly reduces the possibility of pulverized coal overflow. This application adopts a sealing form that combines dynamic and static seals and complements each other, which effectively reduces the pulverized coal leakage rate at the coal mill outlet and also reduces the air leakage rate at this location.

[0012] When the graphite packing needs to be replaced, simply open the cover to remove and replace it. The graphite packing is a strip structure, which can be cut to the required length and placed inside the equipment. The cover is a multi-segment ring structure. The multiple segments form a ring, which facilitates disassembly and installation.

[0013] Beneficial effects: This utility model has the following technical effects when used:

[0014] 1. Significantly improved sealing performance: By sequentially installing a sealing ring, a sealing retaining ring, and graphite packing between the spiral pipe and the outlet short pipe, multiple sealing barriers are formed. The gap fit between the sealing ring and the sealing retaining ring, combined with the filling of the gap by the graphite packing, makes it virtually impossible for pulverized coal to leak out through the gap, effectively avoiding the powder leakage problem common in traditional sealing structures.

[0015] 2. Combination of dynamic and static sealing: The sealing ring and the sealing retaining ring are rotatably connected, combined with the static seal of the graphite packing, forming a sealing structure that combines dynamic and static elements and complements each other. This design not only improves sealing reliability but also accommodates slight misalignment or vibration that may occur during operation of the outlet short circuit, thereby significantly reducing powder leakage and air leakage rates.

[0016] 3. Easy maintenance and replacement: The graphite packing has a strip structure that can be flexibly cut to size as needed, facilitating installation. The graphite packing can be quickly disassembled and replaced by opening the pressure cap, which not only shortens maintenance time but also reduces operational difficulty, significantly improving equipment maintenance efficiency.

[0017] 4. Extend equipment service life; This sealing device effectively reduces coal powder leakage and air leakage, avoids coal powder corrosion of the external environment, thereby improving the overall operational stability of the coal mill and extending the service life of related components. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the utility model.

[0019] Figure 2 This is a schematic diagram of a graphite packing structure for a utility model.

[0020] Figure 3 This is a partial structural schematic diagram of the utility model.

[0021] Figure 4 This is a schematic diagram of the sealing ring and spiral strip structure of a utility model.

[0022] Figure 5 This is a schematic diagram of the outlet short pipe and sealing ring structure of a utility model.

[0023] Figure 6 This is a partial structural cross-sectional view of the utility model.

[0024] Explanation of reference numerals in the attached figures:

[0025] 1. Spiral tube, 2. Limiting ring, 3. Gland, 4. Outlet short connector, 5. Outlet pipe, 6. Bolt, 7. Sealing ring, 8. Spiral strip, 9. Outlet short connector, 10. Sealing ring, 11. Graphite packing. Detailed Implementation

[0026] Example 1, such as Figure 1-6 As shown, the purpose of this utility model is achieved as follows: A novel sealing device for the hollow shaft outlet of a coal mill includes a spiral tube 1. A sealing ring 7 is fixedly installed on the inner side of the right end of the spiral tube 1. An outlet short connector 4 is connected to the right end of the spiral tube 1. An outlet short connector 9 is connected to the lower end of the outlet short connector 4. A sealing ring 10 is fixedly installed on the outer side of the outlet short connector 9. A graphite packing 11 is installed on the right side of the sealing ring 10. A limit ring 2 is fixedly installed on the outer side of the right end of the spiral tube 1. A pressure cap 3 is connected to the right side of the limit ring 2. Multiple spiral strips 8 are installed on the inner side of the spiral tube 1 to the left of the sealing ring 7.

[0027] The sealing retaining ring 7 is rotatably fitted onto the outer side of the sealing ring 10, and the sealing retaining ring 7 and the sealing ring 10 are rotatably connected. The pressure cap 3 and the limiting ring 2 are detachably connected, used for disassembling and installing the outlet short connector 4 and the spiral tube 1. A bolt 6 is provided between the pressure cap 3 and the limiting ring 2, and the pressure rod and the limiting ring 2 are fixedly connected by the bolt 6. An outlet pipe 5 is provided at the upper end of the outlet short connector 4. The outer dimension of the outlet short connector 4 is smaller than the inner dimension of the outlet short connector 4.

[0028] In this application, the spiral tube 1 on the coal mill is located on the equipment. The spiral tube 1 is existing technology on coal mill equipment. The outlet short pipe 9 is then placed inside the spiral tube 1. At this time, the sealing ring 7 is located on the outer side of the sealing ring 10, and the sealing ring 10 and the sealing ring 7 are in clearance fit. The outlet short pipe 4 is then fixed (the outlet short pipe 4 is fixed by external placement. The specific fixing method is not technically limited and depends on the workshop conditions, as long as it does not move or rotate). The graphite packing 11 is then placed around the right side of the sealing ring 10 and the sealing ring 7, so that the left side of the graphite packing 11 is in contact with the sealing ring 10 and the sealing ring 7. The pressure cap 3 is then fixed to the limiting ring 2 by bolts 6 to achieve a fixed seal. The lower left side of the pressure cap 3 is squeezed and sealed to the graphite packing 11.

[0029] The above-mentioned sealing method can prevent pulverized coal from overflowing directly through the outer side wall of the outlet short pipe 9 and then through the inner or outer side of the graphite packing 11. By setting the sealing ring 10 and the sealing retaining ring 7, the gap between the outlet short pipe 9 and the spiral pipe 1 is only the gap formed between the sealing ring 10 and the sealing retaining ring 7, and the right side of this gap is filled and contacted by the left side of the graphite packing 11, which greatly reduces the possibility of pulverized coal overflow. This application further adopts a sealing form that combines dynamic and static seals and complements each other, effectively reducing the pulverized coal leakage rate at the coal mill outlet, and also reducing the air leakage rate at this location.

[0030] When the graphite packing 11 needs to be replaced, simply open the pressure cap 3 to remove and replace the graphite packing 11. The graphite packing 11 is a strip structure, which can be cut to the required length and placed inside the equipment. The pressure cap 3 can be designed as a ring composed of multiple segments to facilitate disassembly and installation.

[0031] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0032] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. For those skilled in the art, the present utility model can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A novel hollow shaft sealing device for a coal mill outlet, comprising a spiral tube, characterized in that: A sealing ring is fixedly installed on the inner side of the right end of the spiral tube. An outlet short connector is connected to the right end of the spiral tube. An outlet short connector pipe is connected to the lower end of the outlet short connector. A sealing ring is fixedly installed on the outer side of the outlet short connector pipe. A graphite packing is installed on the right side of the sealing ring. A limit ring is fixedly installed on the outer side of the right end of the spiral tube. A pressure cap is connected to the right side of the limit ring.

2. The novel hollow shaft sealing device for coal mill outlet according to claim 1, characterized in that: Multiple spiral strips are provided on the inner side of the spiral tube on the left side of the sealing ring.

3. The novel hollow shaft sealing device for coal mill outlet according to claim 1, characterized in that: The sealing retaining ring is rotatably fitted onto the outer side of the sealing ring.

4. The novel hollow shaft sealing device for coal mill outlet according to claim 1, characterized in that: The pressure cap and the limiting ring are detachably connected.

5. The novel hollow shaft sealing device for coal mill outlet according to claim 4, characterized in that: Bolts are provided between the pressure cap and the limiting ring to fix the pressure rod and the limiting ring together.

6. The novel hollow shaft sealing device for coal mill outlet according to claim 1, characterized in that: An outlet pipe is provided at the upper end of the outlet short circuit.

7. The novel hollow shaft sealing device for coal mill outlet according to claim 1, characterized in that: The outer end dimension of the outlet short circuit is smaller than the inner end dimension of the outlet short circuit.

8. The novel hollow shaft sealing device for coal mill outlet according to claim 4, characterized in that: The gland has a multi-segment ring structure.

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