Device for improving sealing performance of double-inlet and double-outlet steel ball mill

Abstract

The utility model discloses a device for improving the sealing performance of a double-inlet and double-outlet steel ball mill, which comprises a primary air chamber, a booster fan, an electric control valve and a pushing rib plate, the sealing air chamber is fixedly sleeved on the surface of a hollow shaft tube, one end of a sealing air pipeline is communicated and connected with the sealing air chamber, the booster fan and the electric control valve are both arranged on the sealing air pipeline, and the pushing rib plate is arranged on the booster fan. A gap is formed between the cylinder body shaft neck and the hollow shaft tube, and a pushing rib plate which spirally extends towards the coal mill cylinder body is fixedly mounted on the inner wall of the cylinder body shaft neck. Primary air enters the annular dynamic and static gap in the sealing air bag after being pressurized, and the sealing performance can be effectively improved due to the fact that the air pressure of the sealing air is higher than that of the primary air in the coal mill barrel. Meanwhile, when the coal mill barrel runs and rotates, the pushing rib plate pushes pulverized coal in the gap between the barrel shaft neck and the hollow shaft pipe into the coal mill barrel, so that the pulverized coal is prevented from entering the sealed air chamber, the risk of powder leakage of the coal mill is eradicated, the production efficiency is improved, and the cleanliness of the field environment is guaranteed.

Description

Technical Field

[0001] This utility model relates to the technical field of pulverizing equipment for thermal power units, and more specifically, to a device for improving the sealing performance of a double-inlet, double-outlet steel ball mill. Background Technology

[0002] Currently, thermal power units typically use double-inlet, double-outlet steel ball mills, which are highly adaptable to various coal types and widely used. The dynamic and static connection points at both ends usually employ a sealed air structure to prevent the high-pressure air-coal mixture inside the coal mill from leaking out of the seal, polluting the surrounding environment, and causing the coal mill to malfunction and shut down.

[0003] In the standard design of pulverizing systems, a dedicated sealing fan is usually installed. Its air pressure is higher than that of the primary air flowing inside the mill. The sealing fan, with its high pressure, plays a role in sealing the primary air and pulverized coal inside the mill. However, due to the high power consumption, system complexity, large maintenance workload, and high maintenance costs of the separately installed sealing fan, with the increasing pressure for energy conservation and emission reduction in thermal power units and experience, the sealing fan is usually removed and replaced with primary air. This can significantly reduce the power consumption of daily use and reduce the maintenance costs and workload of on-site equipment. However, because the primary air pressure is lower than that of the sealing fan, the sealing effect is not ideal, increasing the risk of pulverized coal leakage from the pulverizer. Once pulverized coal leakage occurs, it not only affects the on-site environment and causes environmental pollution, but in severe cases, it can cause the pulverizer to malfunction and shut down, affecting on-site production. Summary of the Invention

[0004] The purpose of this invention is to provide a device for improving the sealing performance of a double-inlet, double-outlet steel ball mill.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a device for improving the sealing performance of a double-inlet double-outlet steel ball mill, comprising a coal mill cylinder, a primary air fan, a hollow shaft tube and a sealing air chamber, and further comprising a primary air chamber, a booster fan, an electric regulating valve and a pusher rib;

[0006] The outlet of the primary air fan is connected to a primary air duct and a sealed air duct. The primary air duct is connected to the primary air chamber. One end of the primary air chamber is connected to a central hot air duct, which is inserted into a hollow shaft tube. The upper part of the hollow shaft tube is connected to a coal drop pipe, and the other end of the hollow shaft tube is inserted into the cylinder journal of the coal mill cylinder.

[0007] The sealed air chamber is fixedly sleeved on the surface of the hollow shaft tube, one end of the sealed air duct is connected to the sealed air chamber, and the booster fan and electric regulating valve are both installed on the sealed air duct.

[0008] There is a gap between the cylinder journal and the hollow shaft tube. A pusher rib extending spirally towards the coal mill cylinder is fixedly installed on the inner wall of the cylinder journal. When the cylinder journal rotates, the pusher rib pushes the coal powder in the gap between the cylinder journal and the hollow shaft tube into the coal mill cylinder.

[0009] Preferably, the sealing chamber is an annular box-shaped structure with an annular groove on one side surface. One end of the cylinder journal is inserted into the annular groove. An inner supporting sealing ring plate is fixedly installed inside the sealing chamber near the annular groove. One end of the cylinder journal is in rolling contact with the inner supporting sealing ring plate. An outer sealing ring plate is fixedly installed at the gap between the cylinder journal and the annular groove.

[0010] Preferably, it also includes a control circuit board, which controls the power of the booster fan and the opening degree of the electric regulating valve through the coal feed rate signal and the material level signal inside the coal mill cylinder.

[0011] Preferably, an integral convex ring is fixedly provided on one side of the inner support sealing ring plate. A ring groove is formed on the surface of the convex ring, and multiple rollers are evenly rotatably installed in the ring groove. The rollers make rolling contact with the inner wall of the cylinder journal.

[0012] Preferably, the contact area between the primary air chamber and the hollow shaft tube is sealed by a sealing ring.

[0013] Preferably, the top of the sealed air chamber is provided with an air inlet, which is connected to the sealed air duct.

[0014] Compared with the prior art, the advantages of this utility model are:

[0015] This invention increases the air pressure of the primary air blower by using a booster fan. After being pressurized, the primary air enters the annular dynamic-static gap within the sealed air chamber. Since the air pressure of the sealed air is higher than that of the primary air inside the coal mill cylinder, it can effectively improve the sealing performance. At the same time, when the coal mill cylinder rotates, the pusher ribs push the coal powder in the gap between the cylinder journal and the hollow shaft tube into the coal mill cylinder, thereby preventing coal powder from entering the sealed air chamber, thus eliminating the risk of coal powder leakage from the coal mill, improving production efficiency, and ensuring a clean working environment. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1This is a perspective view of a device for improving the sealing performance of a double-inlet, double-outlet steel ball mill according to this utility model;

[0018] Figure 2 This is a structural diagram of the sealed air chamber of this utility model.

[0019] In the diagram: 1. Coal mill cylinder; 11. Cylinder journal; 2. Primary air chamber; 21. Central hot air duct; 3. Primary air fan; 4. Booster fan; 5. Electric regulating valve; 6. Sealed air chamber; 61. Air inlet; 62. Inner support sealing ring plate; 63. Roller; 64. Outer sealing ring plate; 7. Hollow shaft tube; 71. Coal drop pipe; 8. Pushing rib plate; 9. Control circuit board. Detailed Implementation

[0020] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the scope of protection of the present invention.

[0021] See Figures 1-2 As shown, this utility model provides a device for improving the sealing performance of a double-inlet double-outlet steel ball mill, including a mill cylinder 1, a primary air fan 3, a hollow shaft tube 7, and a sealing air chamber 6. In the prior art, the hollow shaft tube 7 of the mill is connected to the coal drop pipe 71. When the mill is working, the hollow shaft tube 7 remains stationary. The mill cylinder journal 11, which is sleeved on the outer ring of the hollow shaft tube 7, rotates with the mill. The outer circle of the cylinder journal 11 and the hollow shaft tube 7 form a relative rotational motion. The annular dynamic and static gap between the two needs to be sealed. Therefore, this device also includes a primary air chamber 2, a booster fan 4, an electric regulating valve 5, and a pusher rib 8.

[0022] The outlet of the primary air fan 3 is connected to a primary air duct and a sealed air duct. The primary air duct is connected to the primary air chamber 2. One end of the primary air chamber 2 is connected to a central hot air duct 21, which is inserted into the hollow shaft tube 7. The upper part of the hollow shaft tube 7 is connected to a coal drop pipe 71, and the other end of the hollow shaft tube 7 is inserted into the cylinder journal 11 of the coal mill cylinder 1.

[0023] The sealed air chamber 6 is fixedly sleeved on the surface of the hollow shaft tube 7. One end of the sealed air duct is connected to the sealed air chamber 6. The booster fan 4 and the electric regulating valve 5 are both installed on the sealed air duct.

[0024] There is a gap between the cylinder journal 11 and the hollow shaft tube 7. A pusher rib 8 extending spirally toward the coal mill cylinder 1 is fixedly installed on the inner wall of the cylinder journal 11. When the cylinder journal 11 rotates, the pusher rib 8 pushes the coal powder in the gap between the cylinder journal 11 and the hollow shaft tube 7 into the coal mill cylinder 1.

[0025] In this embodiment, the sealing air chamber 6 is an annular box-shaped structure with an annular groove on one side surface. One end of the cylindrical journal 11 is inserted into the annular groove. An inner supporting sealing ring plate 62 is fixedly installed inside the sealing air chamber 6 near the annular groove. One end of the cylindrical journal 11 is in rolling contact with the inner supporting sealing ring plate 62. An outer sealing ring plate 64 is fixedly installed at the gap between the cylindrical journal 11 and the annular groove.

[0026] In this embodiment, a control circuit board 9 is also included. The control circuit board 9 controls the power of the booster fan and the opening degree of the electric regulating valve 5 through the coal feed signal and the material level signal in the coal mill cylinder 1.

[0027] Furthermore, to ensure that the cylinder journal 11 can rotate smoothly, in this embodiment, an integral convex ring is fixedly provided on one side of the inner support sealing ring plate 62. A ring groove is opened on the surface of the convex ring, and multiple rollers 63 are evenly installed in the ring groove. The rollers 63 roll in contact with the inner wall of the cylinder journal 11.

[0028] Furthermore, to prevent coal dust from leaking from the contact area between the primary air chamber 2 and the hollow shaft tube 7, in this embodiment, the contact area between the primary air chamber 2 and the hollow shaft tube 7 is sealed with a sealing ring.

[0029] In this embodiment, the top of the sealed air chamber 6 is provided with an air inlet 61, which is connected to the sealed air duct.

[0030] The specific operating steps are as follows: The pressure of the primary air fan 3 is increased by 2-5 kPa by the booster fan 4. After being boosted, the primary air enters the annular dynamic and static gap in the sealing air 6. Since the pressure of the sealing air is higher than the pressure of the primary air in the coal mill cylinder 1, the sealing performance can be effectively improved.

[0031] At the same time, the pressure and flow rate of the booster air can be automatically adjusted according to the needs inside the coal mill to further adjust the sealing performance; the air pressure can also be adjusted according to the material level signal. When the material level is too high, the opening of the electric regulating valve 5 can be increased to improve the sealing capacity.

[0032] When the coal mill cylinder 1 is running and rotating, the pusher rib 8 pushes the coal powder in the gap between the cylinder journal 11 and the hollow shaft tube 7 into the coal mill cylinder 1, thereby preventing the coal powder from entering the sealed air chamber 6.

[0033] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, the patent owner may make various modifications or alterations within the scope of the appended claims, as long as they do not exceed the protection scope described in the claims of the present invention, they shall all be within the protection scope of the present invention.

Claims

1. A device for improving the sealing performance of a double-inlet, double-outlet steel ball mill, comprising a mill cylinder, a primary air fan, a hollow shaft tube, and a sealing air chamber, characterized in that: It also includes a primary air chamber, a booster fan, an electric regulating valve, and push ribs; The outlet of the primary air fan is connected to a primary air duct and a sealed air duct. The primary air duct is connected to the primary air chamber. One end of the primary air chamber is connected to a central hot air duct, which is inserted into a hollow shaft tube. The upper part of the hollow shaft tube is connected to a coal drop pipe, and the other end of the hollow shaft tube is inserted into the cylinder journal of the coal mill cylinder. The sealed air chamber is fixedly sleeved on the surface of the hollow shaft tube, one end of the sealed air duct is connected to the sealed air chamber, and the booster fan and electric regulating valve are both installed on the sealed air duct. There is a gap between the cylinder journal and the hollow shaft tube. A pusher rib extending spirally towards the coal mill cylinder is fixedly installed on the inner wall of the cylinder journal. When the cylinder journal rotates, the pusher rib pushes the coal powder in the gap between the cylinder journal and the hollow shaft tube into the coal mill cylinder.

2. The device for improving the sealing performance of a double-inlet, double-outlet steel ball mill according to claim 1, characterized in that: The sealing chamber is an annular box-shaped structure with an annular groove on one side surface. One end of the cylinder journal is inserted into the annular groove. An inner support sealing ring plate is fixedly installed inside the sealing chamber near the annular groove. One end of the cylinder journal is in rolling contact with the inner support sealing ring plate. An outer sealing ring plate is fixedly installed at the gap between the cylinder journal and the annular groove.

3. The device for improving the sealing performance of a double-inlet, double-outlet steel ball mill according to claim 1, characterized in that: It also includes a control circuit board, which controls the power of the booster fan and the opening of the electric regulating valve through the coal feed signal and the material level signal inside the coal mill cylinder.

4. The device for improving the sealing performance of a double-inlet, double-outlet steel ball mill according to claim 2, characterized in that: One side of the inner support sealing ring plate is fixed with an integral convex ring. A ring groove is opened on the surface of the convex ring. Multiple rollers are evenly installed in the ring groove and roll in contact with the inner wall of the cylinder journal.

5. The device for improving the sealing performance of a double-inlet, double-outlet steel ball mill according to claim 1, characterized in that: The contact area between the primary air chamber and the hollow shaft tube is sealed by a sealing ring.

6. The device for improving the sealing performance of a double-inlet, double-outlet steel ball mill according to claim 1, characterized in that: The top of the sealed air chamber has an air inlet, which is connected to the sealed air duct.

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