CN220268433U

CN220268433U - Cross shaft seal structure of grinding roller support arm of medium-speed coal mill

Info

Publication number: CN220268433U
Application number: CN202321164741.4U
Authority: CN
Inventors: 刘冠男; 张金栋; 何淼; 赵久特; 刘文峰
Original assignee: Yingkou Power Plant of Huaneng Power International Inc
Current assignee: Yingkou Power Plant of Huaneng Power International Inc
Priority date: 2023-05-15
Filing date: 2023-05-15
Publication date: 2023-12-29
Anticipated expiration: 2033-05-15

Abstract

The invention relates to thermal power plants, metallurgy, steel and other technical fields with large and medium-sized coal grinding mills, especially a medium-speed coal grinding mill roller arm transverse shaft seal structure, including a grinding roller frame and a grinding roller frame. There are transverse shafts on both sides of the outer wall. The two transverse shafts are equipped with shaft seal components near the grinding roller frame. The shaft seal assembly consists of a sealing block and a packing gland. The packing gland is located on the sealing block away from the grinding roller frame. On one side of the ring block, the sealing block is composed of a first ring block and a second ring block. A sealing chamber is provided in the inner ring of the first ring block. There is a floating sealing ring in the sealing chamber. There is a sealing ring in the second ring block that communicates with the sealing chamber. Sealed air chamber. This application adopts a new technology of floating ring seal + sealing air, which not only eliminates the stubborn problem of powder leakage from the horizontal axis of the grinding roller arm, improves the working environment, reduces labor intensity, but also has obvious effects on cost saving and improving work efficiency. Effect.

Description

Cross shaft seal structure of grinding roller support arm of medium-speed coal mill

Technical Field

The utility model relates to the technical field of coal pulverizing of large and medium-sized coal mills in thermal power plants, metallurgy, steel and the like, in particular to a transverse shaft seal structure of a grinding roller support arm of a medium-speed coal mill.

Background

The coal mill of the one-stage two-boiler pulverizing system of the Wacan barrate power plant adopts a Russian medium-speed coal mill, and the model is MBC-225. The two grinding rollers of the coal mill are symmetrically arranged above the grinding disc, a certain gap is reserved between the grinding rollers and the grinding disc for grinding the coal seam, the gap is regulated by mechanical limit at two ends on the grinding roller support arm, and meanwhile, the mechanical limit at two ends is controlled by a hydraulic system respectively to apply grinding force to the grinding rollers. Because the thickness of the coal layer changes greatly when the grinding roller rolls the coal layer, the transverse shaft of the support arm frequently vibrates (generally, the vibration angle of the transverse shaft is about 10-15 degrees). The coal mill runs in the environment with high temperature, large coal seam change and positive pressure for a long time, and in order to prevent the outward leakage of hot air and coal dust, the original design of the two ends of the transverse shaft on the support arm of the grinding roller adopts filling materials for sealing. Because of the long-time mechanical movement of the transverse shaft of the support arm, the packing and the shaft diameter are inevitably worn so as to leak powder, the influence on the surrounding environment is relatively large, the field non-civilization degree is increased, the system operation reliability is reduced, and the equipment maintenance amount is increased. In order to further radically cure the stubborn powder leakage of the transverse shaft of the grinding roller support arm, improve the reliabilities of civilized production and equipment of a boiler pulverizing system, the sealing structure of the transverse shaft of the grinding roller support arm of a medium-speed coal mill in the boiler pulverizing system is technically compromised.

Disclosure of Invention

The utility model aims to provide a transverse shaft seal structure of a grinding roller support arm of a medium-speed coal mill, so as to solve the problems in the background art.

In order to achieve the above purpose, the present utility model provides the following technical solutions:

the utility model provides a medium speed pulverizer grinding roller support arm cross axle bearing seal structure, includes the grinding roller frame, the both sides outer wall of grinding roller frame all is equipped with the cross axle, two the cross axle is close to grinding roller frame department and all overlaps and be equipped with the bearing seal subassembly, the bearing seal subassembly comprises sealing block and packing gland, the packing gland is located one side that the grinding roller frame was kept away from to the sealing block, the sealing block comprises first ring piece and second ring piece, the seal chamber has been seted up to the inner circle of first ring piece, be equipped with floating seal ring in the seal chamber, be equipped with in the second ring piece with the communicating sealed plenum of seal chamber.

As a preferable scheme of the utility model, the floating sealing ring is of a split structure, and two ends of the floating sealing ring are connected by welding.

As a preferable scheme of the utility model, the inner diameter of the floating sealing ring is 340+/-0.3 mm.

As a preferable scheme of the utility model, the radial clearance between the floating sealing ring and the sealing chamber is 5mm, and the axial clearance between the floating sealing ring and the sealing chamber is 0.8mm.

In a preferred embodiment of the present utility model, the diameter of the transverse axis is 340±0.2mm, the roundness of the transverse axis is less than 0.1mm, and the roughness of the transverse axis is 6.3.

As a preferable scheme of the utility model, the first ring block and the second ring block are integrally arranged, the inner diameter of the second ring block is larger than that of the first ring block, and the wall bodies of the first ring block and the second ring block are provided with plugs at the sealed air chamber.

As a preferable scheme of the utility model, a graphite nickel wire packing and an O-shaped fluorine rubber strip are sequentially arranged at the inner diameter of the outer ring of the transverse shaft, and a packing gland is arranged at one side of the O-shaped fluorine rubber strip, which is far away from the graphite nickel wire packing.

As a preferable scheme of the utility model, the inner ring wall and the outer ring wall of the O-shaped fluorine rubber strip and the graphite nickel wire packing are respectively contacted with the outer wall of the transverse shaft and the inner diameter wall of the second ring block.

As a preferable scheme of the utility model, the outer walls of the two sides of the O-shaped fluorine rubber strip are respectively contacted with the ends of the graphite nickel wire packing and the packing gland.

As a preferable scheme of the utility model, the outside of two ends of the second ring block is provided with a sealing air pipeline communicated with the sealing air chamber.

Compared with the prior art, the utility model has the beneficial effects that: aiming at the problems presented in the background art, the main effects and advantages of the utility model are as follows:

1. the grinding roller support arm transverse shaft floating ring and sealing wind technology is designed and arranged in a contact mode, and the grinding roller support arm transverse shaft floating ring and sealing wind technology is reasonable in process and compact in structure.

2. Because the novel technology of floating ring and sealing wind is adopted, the characteristics of abrasion of a transverse shaft, constant close contact of the floating ring and the transverse shaft, original sealing outdoor sealing wind and external packing sealing design and the like are reserved. Not only radically curing the stubborn diseases of a large amount of leakage of the coal powder of the transmission shaft, but also reducing the equipment maintenance cost and the maintenance labor cost and improving the equipment use efficiency.

3. The maintenance amount is small, the maintenance is convenient, and the maintenance service cycle is long.

The novel technology of floating ring sealing and sealing wind is adopted, so that not only can the stubborn powder leakage of the transverse shaft of the grinding roller support arm be radically cured, the working environment be improved, the labor intensity is lightened, but also the cost is saved, the working efficiency is improved, and the obvious effect is achieved.

Drawings

FIG. 1 is a schematic diagram of the overall structure of the present utility model;

FIG. 2 is a front view of the present utility model;

FIG. 3 is a cross-sectional view of the shaft seal assembly of the present utility model;

FIG. 4 is a schematic view of a seal block of the present utility model;

FIG. 5 is an enlarged view of the utility model at A;

FIG. 6 is a schematic view of the gap between the floating ring and the seal chamber of the present utility model.

In the figure: 1. grinding a roller frame; 2. a horizontal axis; 3. a shaft seal assembly; 4. packing gland; 5. an O-shaped fluorine rubber strip; 6. graphite nickel wire packing 7 and sealing the air pipeline; 8. a sealing block; 9. a first loop block; 901. a sealed chamber; 902. a floating seal ring; 903. sealing the air chamber; 904. plugging; 10. and a second ring block.

Detailed Description

The technical solutions of the embodiments of the present utility model will be clearly and completely described below in conjunction with the embodiments of the present utility model, and it is apparent that the described embodiments are only some embodiments of the present utility model, but not all embodiments, and all other embodiments obtained by those skilled in the art without making any inventive effort based on the embodiments of the present utility model are within the scope of protection of the present utility model.

In order that the utility model may be readily understood, a more complete description of the utility model will be rendered by reference to the appended drawings. Several embodiments of the utility model are presented. This utility model may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "mounted" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like are used herein for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model belongs. The terminology used herein in the description of the utility model is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1-6, the present utility model provides a technical solution:

the utility model provides a medium speed coal mill grinding roller support arm cross shaft seal structure, including grinding roller frame 1, grinding roller frame 1's both sides outer wall all is equipped with cross shaft 2, cross shaft 2's diameter of axle is 340+ -0.2 mm, cross shaft 2's circularity is less than 0.1mm, and cross shaft 2's roughness is 6.3, two cross shafts 2 all overlap near grinding roller frame 1 department and are equipped with shaft seal subassembly 3, shaft seal subassembly 3 comprises sealing block 8 and packing gland 4, packing gland 4 is located sealing block 8 and keeps away from one side of grinding roller frame 1, sealing block 8 comprises first ring piece 9 and second ring piece 10, sealing chamber 901 has been seted up to the inner circle of first ring piece 9, be equipped with floating seal ring 902 in the sealing chamber 901, floating seal ring 902 is split structure, floating seal ring 902's both ends adopt welded connection, floating seal ring 902's internal diameter is 340+ -0.3 mm, floating seal ring 902 and sealing chamber 901's radial clearance is 5mm, the axial clearance between the floating seal ring 902 and the seal chamber 901 is 0.8mm, a seal air chamber 903 communicated with the seal chamber 901 is arranged in the second ring block 10, a seal air pipeline 7 communicated with the seal air chamber 903 is arranged outside the two ends of the second ring block 10, the first ring block 9 and the second ring block 10 are integrally arranged, the inner diameter of the second ring block 10 is larger than that of the first ring block 9, plugs 904 are arranged on the wall bodies of the first ring block 9 and the second ring block 10 at the seal air chamber 903, a graphite nickel wire packing 6 and an O-shaped fluorine rubber strip 5,O type fluorine rubber strip 5 are sequentially arranged on the outer ring of the transverse shaft 2 at the inner diameter of the second ring block 10, a packing gland 4,O type fluorine rubber strip 5 and an inner ring wall and an outer ring wall of the graphite nickel wire packing 6 are respectively contacted with the outer wall of the transverse shaft 2 and the inner diameter wall of the second ring block 10, the outer walls of the two sides of the O-shaped fluorine rubber strip 5 are respectively contacted with the ends of the graphite nickel wire packing 6 and the packing gland 4.

The utility model creates technology, demolish the packing structure of the horizontal shaft of the original grinding roller support arm, and process and repair the shaft diameter worn part that the original packing contacts, the tolerance 340+ -0.2 mm of shaft diameter, the roundness is not more than 0.1mm, roughness is about 6.3, redesign a set of sealing device in the original sealed position, design a set of floating seal ring 902 in the sealed chamber 901, require the inner diameter of the floating seal ring 902 to process and guarantee 340+ -0.3 mm, weld the split after installing in place, make the floating seal ring 902 an entirety, wherein the floating seal ring 902 and the sealed chamber 901 radial clearance design 5mm, the floating seal ring 902 and the sealed chamber 901 axial clearance design 0.8mm, guarantee that the floating seal ring 902 and the horizontal shaft 2 are in an integral way in work, shake along with the horizontal shaft 2, and relatively stationary with the horizontal shaft 2, the clearance change of the sealed part of the floating seal ring 902 and the horizontal shaft 2 is not great, make the powder leakage amount reduce, keep the original seal wind design in the axial clearance of the floating seal ring 902 and the sealed chamber 901, because the seal wind pressure is higher than the pressure of the coal mill wind-powder mixture, can stop the pressure of sealing block effectively, but seal wire seal ring 8 and seal ring 8 have no pollution of sealing device of sealing wire seal ring 6 outside the grinding roller, the maintenance cost is reduced, but the maintenance equipment of the seal wire seal ring has been completely and the cost is reduced by using the sealing wire seal ring 6.

The arrow in fig. 5 indicates the direction of powder leakage travel, and it is seen that there are two channels for powder leakage, namely, a gap channel between the floating seal ring 902 and the axial direction of the cross shaft 2, and this channel has to meet the requirements that the floating seal ring 902 has no relative movement with respect to the sealing position of the cross shaft 2 in normal operation of the coal mill due to the precision of design, processing and assembly, so that the cross shaft 2 has no friction and no abrasion, the gap between the floating seal ring 902 and the sealing position of the cross shaft 2 is basically unchanged, and the powder leakage amount is small. Secondly, powder is leaked through the delta 2 clearance of the floating seal ring 902, the clearance on the floating seal ring 902 and the delta 1 clearance, and due to the deviation of the installation process of the floating seal ring 902, the floating seal ring 902 is arranged at three possible positions of the seal chamber 901:

(1) The floating seal ring 902 is in the neutral position, Δ1=Δ2=1/2, the gap is designed, the floating seal ring 902 does not rub with two sides of the seal chamber 901 during operation, which is an ideal position, and the gap value is 0.3-0.4mm.

(2) The floating seal ring 902 is adjacent to the packing, the gap Δ1 < Δ2, and Δ1 may be zero, and friction with the seal chamber 901 during operation causes the gap Δ2 to increase continuously.

(3) The floating seal ring 902 is on the coal mill side, the gap Δ1 > Δ2, and Δ2 may be zero, and friction with the seal chamber 901 during operation causes the gap Δ1 to increase continuously.

Sealing wind concentrates in the annular sealing chamber 901 after passing through the channels, powder leakage of the two channels is balanced along the reverse direction of the powder leakage stroke, the radial clearance between the floating sealing ring 902 and the sealing surface of the transverse shaft 2 is small, the working clearance is unchanged, the sealing wind quantity of the floating sealing ring 902 at the position of the transverse shaft 2 is small, one of delta 1 and delta 2 of the floating sealing ring 902 in three positions of the sealing chamber 901 is smaller than 0.4mm, the allowable design value is lower than 0.5mm, and the pressure head of the sealing wind meets the sealing theory.

In practice, when the floating seal ring 902 is mounted in a sealing manner, the floating seal ring 902 is first in contact with the seal chamber 901, and moves along with the seal chamber 901 in the axial direction during the bolt fastening process of the seal end cap, and when the seal end cap is in place, the axial clearance between the floating seal ring 902 and the seal chamber 901 is in the position as shown in fig. 6, and the clearance value in the position is theoretically Δ1=Δ4=0, Δ2=Δ3=0.8 mm, but in practice, the theoretical value cannot be reached due to manufacturing, assembly errors and elastic effects.

The working flow of the utility model is as follows: the method comprises the steps of dismantling a packing sealing structure of a cross shaft of an original grinding roller support arm, machining and repairing a shaft diameter worn part contacted with original packing, wherein the shaft diameter tolerance is 340+/-0.2 mm, the roundness is not more than 0.1mm, the roughness is about 6.3, a set of sealing device is redesigned at an original sealing position, a set of floating sealing ring 902 is designed in a sealing chamber 901, the inner diameter of the floating sealing ring 902 is required to be machined to ensure 340+/-0.3 mm, after the floating sealing ring 902 is installed in place, the split joint is welded to form a whole, the radial clearance between the floating sealing ring 902 and the sealing chamber 901 is designed to be 5mm, the axial clearance between the floating sealing ring 902 and the sealing chamber 901 is designed to be 0.8mm, the floating sealing ring 902 and the cross shaft 2 are guaranteed to be integrated in operation, the floating sealing ring 902 vibrates along with the cross shaft 2 and is relatively static along with the cross shaft 2, the clearance between the floating sealing ring 902 and the cross shaft 2 is not large, the leakage amount is reduced, the original sealing wind design is reserved in the axial clearance between the floating sealing ring 902 and the sealing chamber 901, the sealing wind pressure is higher than the pressure of a coal mill wind mixture, the coal dust can be effectively prevented from leaking outwards, and meanwhile, and the sealing ring 8 and the sealing ring 4 and the packing rubber strip 4 are compressed tightly press against the outer packing 4 by a seal wire 4O 6.

Although embodiments of the present utility model 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 therein without departing from the principles and spirit of the utility model, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides a medium speed pulverizer grinding roller support arm cross axle bearing seal structure, includes grinding roller frame (1), its characterized in that: the utility model discloses a grinding roller frame, including grinding roller frame (1), bearing seal, sealing ring (902), sealing ring (903) and sealing chamber (901), bearing seal (2), sealing ring (4) are located sealing block (8), and sealing ring (9) and second annular piece (10) are constituteed in both sides outer wall of grinding roller frame (1), two bearing seal (3) are all overlapped in bearing seal (2) department near grinding roller frame (1), bearing seal (3) are constituteed by sealing block (8) and packing gland (4), packing gland (4) are located one side that sealing block (8) kept away from grinding roller frame (1), sealing block (8) are constituteed by first annular piece (9) and second annular piece (10), sealing chamber (901) have been seted up to the inner circle of first annular piece (9), be equipped with floating seal ring (902) in sealing chamber (901), be equipped with in second annular piece (10) with communicating sealing plenum (903).

2. The transverse shaft seal structure of a grinding roller support arm of a medium speed coal mill according to claim 1, wherein: the floating sealing ring (902) is of a split structure, and two ends of the floating sealing ring (902) are connected by welding.

3. The transverse shaft seal structure of a grinding roller support arm of a medium speed coal mill according to claim 1, wherein: the inner diameter of the floating seal ring (902) is 340+/-0.3 mm.

4. The transverse shaft seal structure of a grinding roller support arm of a medium speed coal mill according to claim 1, wherein: the radial clearance between the floating sealing ring (902) and the sealing chamber (901) is 5mm, and the axial clearance between the floating sealing ring (902) and the sealing chamber (901) is 0.8mm.

5. The transverse shaft seal structure of a grinding roller support arm of a medium speed coal mill according to claim 1, wherein: the diameter of the transverse shaft (2) is 340+/-0.2 mm, the roundness of the transverse shaft (2) is smaller than 0.1mm, and the roughness of the transverse shaft (2) is 6.3.

6. The transverse shaft seal structure of a grinding roller support arm of a medium speed coal mill according to claim 1, wherein: the first annular block (9) and the second annular block (10) are integrally arranged, the inner diameter of the second annular block (10) is larger than that of the first annular block (9), and the sealing air chamber (903) is arranged at the positions of the wall bodies of the first annular block (9) and the second annular block (10).

7. The cross shaft seal structure of a grinding roller support arm of a medium speed coal mill according to claim 6, wherein: the graphite nickel wire packing (6) and the O-shaped fluorine adhesive tape (5) are sequentially arranged at the inner diameter of the second annular block (10) on the outer ring of the transverse shaft (2), and a packing gland (4) is arranged on one side, far away from the graphite nickel wire packing (6), of the O-shaped fluorine adhesive tape (5).

8. The cross shaft seal structure of a grinding roller support arm of a medium speed coal mill according to claim 7, wherein: the inner ring wall and the outer ring wall of the O-shaped fluorine rubber strip (5) and the graphite nickel wire packing (6) are respectively contacted with the outer wall of the transverse shaft (2) and the inner diameter wall of the second ring block (10).

9. The cross shaft seal structure of a grinding roller support arm of a medium speed coal mill according to claim 8, wherein: the outer walls of the two sides of the O-shaped fluorine rubber strip (5) are respectively contacted with the ends of the graphite nickel wire packing (6) and the packing gland (4).

10. The transverse shaft seal structure of a grinding roller support arm of a medium speed coal mill according to claim 1, wherein: and sealing air pipelines (7) communicated with the sealing air chambers (903) are arranged outside the two ends of the second ring block (10).