Grinding roller gap adjusting and sealing device of coal mill

Abstract

The invention discloses a grinding roller gap adjusting and sealing device of a coal mill, belongs to the technical field of power generation industry equipment, and aims at solving the problems that an existing HP type coal mill adjusting device is strenuous and low in efficiency, and coal powder leaks. The device comprises a grinding roller head connected with a grinding roller, wherein the top end of the grinding roller head is provided with a U-shaped groove for bearing force; one end of the adjusting pull rod is provided with a T-shaped head matched with the U-shaped groove, the adjusting pull rod is clamped in the U-shaped groove, and the other end of the adjusting pull rod penetrates out of the coal mill shell; the sealing seat is fixed on a shell of the coal mill and is provided with a through hole for the adjusting pull rod to penetrate through, and a filler cavity for accommodating the sealing filler is arranged in the sealing seat; and the gland covers the sealing seat and is used for pressing the sealing filler in the filler cavity so as to form sealing between the adjusting pull rod and the sealing seat. The adjusting mode is changed from low-position pushing to high-position pulling, so that the adjustment is labor-saving and efficient; meanwhile, an external packing sealing structure is adopted, coal powder leakage is eradicated, and potential safety hazards are eliminated.

Description

Technical Field

[0001] This invention relates to the technical field of the power generation industry, and in particular to a device for adjusting and sealing the gap between grinding rollers of a coal mill. Background Technology

[0002] In thermal power plants, the HP-type coal mill is a key piece of equipment for producing pulverized coal, and the gap between its grinding rollers and liners directly affects the grinding efficiency and the fineness of the pulverized coal. However, existing grinding roller gap adjustment systems generally have serious design flaws, mainly in the adjustment mechanism and sealing structure.

[0003] Regarding the adjustment mechanism, the existing screw-driven adjustment system suffers from a fatal mechanical structural defect. The screw's pushing point is typically located below the eccentric shaft connection of the grinding roller, creating an extremely unfavorable lever effect under the weight of the several-ton grinding roller. This forces maintenance personnel to overcome enormous frictional torque during gap adjustment, making the operation extremely laborious and time-consuming. A complete gap calibration requires several man-hours, severely restricting maintenance efficiency, and the adjustment accuracy is difficult to guarantee, directly impacting the economical operation of the coal mill.

[0004] Regarding the sealing structure, most existing systems employ a simple connection between the adjusting screw and the threaded bushing. This T-shaped threaded connection inherently has radial clearance, which, under the influence of high-pressure air (typically 0.35-0.45 MPa) inside the mill, becomes a continuous and significant channel for coal dust leakage. This leakage leads to three serious consequences: First, a large amount of coal dust leaks into the working environment, causing dust concentrations to exceed standards and endangering the occupational health of operators; second, the leaked coal dust deposits and caking on the surfaces of adjusting and transmission components, exacerbating abnormal wear of the equipment and significantly shortening the service life of critical components such as the screw and bushing; third, under conditions of electrostatic accumulation, the high concentration of coal dust poses a significant risk of dust explosion, constituting a major production safety hazard.

[0005] In view of the above problems, the structural defects of the existing coal mill adjustment system have led to many problems such as high maintenance costs, low maintenance efficiency, increased unplanned downtime of the unit, and serious safety hazards. There is an urgent need for a coal mill roller gap adjustment and sealing device to fundamentally solve the above technical problems. Summary of the Invention

[0006] In view of this, this application provides a grinding roller gap adjustment and sealing device for a coal mill. The main purpose is to solve the technical problems of existing HP-type coal mill gap adjustment devices, such as laborious adjustment, low efficiency, serious coal powder leakage, and safety hazards.

[0007] According to a first aspect of the present invention, a grinding roller gap adjustment and sealing device for a coal mill is provided for adjusting the gap between the grinding roller and the liner, comprising: a grinding roller head connected to the grinding roller, wherein the core innovation is that the top end of the grinding roller head is provided with a U-shaped groove for bearing force;

[0008] An adjusting rod is provided, one end of which has a T-shaped head that mates with the U-shaped groove. The T-shaped head is engaged in the U-shaped groove to efficiently apply the adjusting force to the top of the grinding roller head, forming a favorable mechanical lever. The other end of the adjusting rod extends out of the coal mill housing for external operation.

[0009] A sealing seat is fixed to the coal mill housing and has a through hole for the adjusting rod to pass through. Its core innovation lies in the fact that the sealing seat contains a packing cavity for accommodating sealing packing (such as packing).

[0010] And a pressure cap, which is disposed on the sealing seat and is used to compress the sealing packing in the packing cavity to form a reliable, adjustable dynamic seal between the reciprocating adjusting rod and the sealing seat.

[0011] Furthermore, the adjusting rod is a T-bolt, with a threaded end that protrudes from the coal mill housing and engages with an adjusting nut, thereby achieving precise and labor-saving gap adjustment.

[0012] Furthermore, the gland is detachably fixed to the sealing seat by multiple bolts, which facilitates the inspection, adjustment and replacement of the internal sealing packing.

[0013] Furthermore, the sealing packing is packing.

[0014] Furthermore, the grinding roller gap adjustment and sealing device of the coal mill further includes: a roller frame connected to the grinding roller head, the two ends of the roller frame extending and having mounting holes for mounting support shafts.

[0015] Furthermore, a rubber sleeve is provided in the mounting hole of the roller frame, and a support shaft passes through the rubber sleeve.

[0016] Furthermore, the roller frame is also provided with a second pressure cap for fixing the support shaft.

[0017] Furthermore, the end of the mounting hole is provided with a groove to facilitate the removal of the rubber sleeve.

[0018] Furthermore, a reinforcing rib is provided on the coal mill casing at the position corresponding to the protrusion of the adjusting rod. The reinforcing rib is arranged around the adjusting rod and is welded and fixed to the coal mill casing.

[0019] Furthermore, according to a second aspect of the invention, a coal mill is provided, including a grinding roller gap adjustment and sealing device as described in any of the foregoing inventions.

[0020] This invention provides a grinding roller gap adjustment and sealing device for a coal mill. By shifting the point of force application from below the grinding roller to the U-shaped groove at the top, and changing the "pushing" action to a "pulling" action, the mechanical model is completely altered, significantly reducing the operating torque. This makes the previously time-consuming and laborious adjustment work easy and quick, which can be completed by a single person, greatly improving maintenance efficiency while ensuring adjustment accuracy. This application adopts a mature and reliable packing gland type dynamic sealing structure, which can completely and permanently seal the high-pressure air and coal dust inside the mill, completely eliminating coal dust leakage channels, purifying the working environment, and protecting personnel health. In addition, by eliminating coal dust leakage, the major safety hazard of deflagration caused by dust accumulation and static electricity is eliminated, ensuring the safety of equipment and personnel.

[0021] The structure of this application is stable and reliable, avoiding wear on transmission components caused by leaked coal dust, extending the service life of the equipment, reducing spare parts consumption and maintenance frequency, and significantly reducing unplanned downtime of the unit, thus saving power generation companies from huge economic losses.

[0022] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0023] The accompanying drawings, as part of this invention, are provided to further illustrate the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention, but do not constitute an undue limitation thereof. Clearly, the drawings described below are merely some embodiments, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0024] In the attached diagram:

[0025] Figure 1 This is a schematic diagram of the overall structure of a grinding roller gap adjustment and sealing device for a coal mill according to an embodiment of the present invention;

[0026] Figure 2 A partial structural schematic diagram of the grinding roller head of the grinding roller gap adjustment and sealing device for a coal mill provided in an embodiment of the present invention is shown;

[0027] Figure 3 A schematic diagram of the overall structure of a coal mill provided in an embodiment of the present invention is shown.

[0028] Icon labels:

[0029] 1. Grinding roller head; 11. U-shaped groove; 2. Adjusting rod; 3. Sealing seat; 4. Pressure cover; 5. Coal mill casing; 6. Packing; 7. Adjusting nut; 8. Roller frame.

[0030] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0032] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] Example 1

[0035] like Figure 1-3 As shown, in one feasible embodiment, this application provides a grinding roller gap adjustment and sealing device for an HP type coal mill. The device mainly includes an improved grinding roller head 1, an adjusting rod 2 (a T-bolt in this embodiment), a sealing seat 3 welded and fixed to the coal mill housing 5, and a pressure cap 4.

[0036] In this embodiment, the front end of the grinding roller head 1 is lengthened, and a U-shaped groove 11 is machined at its top. This U-shaped groove 11 is the key load-bearing part for applying adjustment force.

[0037] The adjusting rod 2 is a specially designed T-bolt, the T-shaped structure of which is adapted to the U-shaped groove 11 at the top of the grinding roller head 1. During assembly, the T-shaped head snaps into the U-shaped groove 11, concentrating the force exerted by the adjusting rod 2 on the grinding roller head 1 at the very top. The shank of the T-bolt passes through an opening in the coal mill housing 5 and extends outside the housing. Outside the housing, the threaded section of the T-bolt engages with an adjusting nut 7. The operator only needs to rotate the adjusting nut 7 to drive the T-bolt axially, thereby pulling or pushing the entire grinding roller assembly to achieve precise adjustment of the gap between the grinding roller and the liner. Due to the greatly optimized lever arm, turning the adjusting nut becomes very effortless.

[0038] To address the coal powder leakage problem, the core improvement in this embodiment lies in the sealing structure. A steel sealing seat 3 is welded to the outer wall of the coal mill housing 5, with its central hole aligned with an opening on the housing, through which the shank of a T-bolt passes. An annular packing cavity is machined inside the sealing seat 5. This packing cavity is filled with wear-resistant, high-temperature-resistant flexible sealing packing, such as multilayer packing 6.

[0039] A pressure cap 4 is provided on the outside of the sealing seat 3. The pressure cap 4 is fastened to the end face of the sealing seat 3 by multiple bolts. When these bolts are tightened, the pressure cap 4 will press the packing 6 inward into the packing cavity, causing the packing 6 to expand radially while being axially compressed, thereby tightly gripping the shank of the T-bolt and forming an extremely tight dynamic seal. This seal allows the T-bolt to move axially at low speed during adjustment, while completely preventing high-pressure air and coal dust inside the mill from leaking outward along the gap in the shank.

[0040] Please refer to the instruction manual attached. Figure 3 As another improvement, the roller frame connected to the grinding roller head 1 has also been optimized. Both ends of the roller frame are extended and have mounting holes for installing support shafts. For vibration reduction and ease of maintenance, a rubber sleeve is first inserted into the mounting hole. A support shaft then passes through this rubber sleeve. Finally, a separate pressure plate is bolted to the end face of the roller frame to axially limit the support shaft. Specifically, to facilitate future replacement of aged rubber sleeves, several special slots are provided at the end of the mounting hole, allowing for easy prying or pulling out of the old rubber sleeves during maintenance.

[0041] In one feasible embodiment, a reinforcing rib is provided on the coal mill housing 5 at the protrusion position of the adjusting rod 2. The reinforcing rib is arranged around the adjusting rod 2 and is welded and fixed to the coal mill housing 5.

[0042] Example 2

[0043] In one feasible implementation, a coal mill is provided, which includes a grinding roller gap adjustment and sealing device as described in any of the embodiments of Example 1 above.

[0044] This invention, through a revolutionary innovation in the mechanical model of the regulating mechanism and the introduction of a mature and reliable industrial-grade dynamic sealing structure, solves the two long-standing problems of regulation difficulty and coal powder leakage in existing technologies in one stop, and has extremely high value for promotion and application.

[0045] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. The implementation schemes in the above embodiments can also be further combined or replaced. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A grinding roller gap adjustment and sealing device for a coal mill, used to adjust the gap between the grinding roller and the liner, characterized in that, include: A grinding roller head (1) connected to the grinding roller, wherein the top end of the grinding roller head (1) is provided with a U-shaped groove (11) for bearing force; Adjusting rod (2), one end of the adjusting rod has a T-shaped head that matches the U-shaped groove, the T-shaped head is locked in the U-shaped groove (11), and the other end of the adjusting rod extends out of the coal mill casing (5); A sealing seat (3) is fixed on the coal mill housing (5) and has a through hole for the adjusting rod to pass through. The sealing seat (3) has a filling cavity for accommodating the sealing filler. A pressure cap (4) is placed on the sealing seat (3) and is used to press the sealing packing in the packing cavity to form a seal between the adjusting rod (2) and the sealing seat (3).

2. The grinding roller gap adjustment and sealing device for a coal mill according to claim 1, characterized in that, The adjusting rod (2) is a T-bolt, and its other end, which protrudes from the coal mill housing (5), is threaded and threadedly engages with an adjusting nut (7).

3. The grinding roller gap adjustment and sealing device for a coal mill according to claim 1, characterized in that, The gland (4) is detachably fixed to the sealing seat (3) by a plurality of bolts.

4. The grinding roller gap adjustment and sealing device for a coal mill according to claim 1, 2 or 3, characterized in that, The sealing packing is packing (6).

5. The grinding roller gap adjustment and sealing device for a coal mill according to claim 1, characterized in that, Also includes: The roller frame (8) is connected to the grinding roller head (1), with both ends of the roller frame extending and having mounting holes for mounting the support shaft.

6. The grinding roller gap adjustment and sealing device for a coal mill according to claim 5, characterized in that, A rubber sleeve is provided in the mounting hole of the roller frame (8), and a support shaft passes through the rubber sleeve.

7. The grinding roller gap adjustment and sealing device for a coal mill according to claim 6, characterized in that, The roller frame (8) is also provided with a second pressure cover for fixing the support shaft.

8. The grinding roller gap adjustment and sealing device for a coal mill according to claim 6, characterized in that, The end of the mounting hole has a groove for easy removal of the rubber sleeve.

9. The grinding roller gap adjustment and sealing device for a coal mill according to claim 1, characterized in that, The coal mill housing (5) is provided with a reinforcing rib plate corresponding to the protrusion position of the adjusting rod (2). The reinforcing rib plate is arranged around the adjusting rod (2) and is welded and fixed to the coal mill housing (5).

10. A coal mill, characterized in that, Includes the grinding roller gap adjustment and sealing device as described in any one of claims 1-9 above.

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