Wear-resistant dynamic and static ring structure of medium-speed coal mill

Abstract

The invention relates to the technical field of coal mills, in particular to a wear-resistant medium-speed coal mill dynamic and static ring structure which comprises a static ring assembly, a dynamic ring assembly, a coal mill shell and a tray. The tray is arranged in an inner cavity of the coal mill shell, the movable ring assembly is fixedly arranged on the tray, and the movable ring assembly and the tray rotate together; the static ring assembly is fixedly connected with the coal mill shell, and the static ring assembly is arranged in the circumferential direction of the dynamic ring assembly; the static ring assembly comprises a static ring unit, a static ring supporting plate support and a static ring supporting plate support base. The multiple sections of static ring units are sequentially connected end to end and form a closed circular ring; the dynamic ring and the static ring are arranged to be a plurality of sections of dynamic ring units and static ring units, the dynamic ring and the static ring can be conveniently and rapidly disassembled and assembled, when the coal mill is abraded, only the static ring unit or the dynamic ring unit which is seriously abraded needs to be replaced, the dynamic ring or the static ring is prevented from being integrally disassembled and assembled, the maintenance time and cost are saved, the dynamic ring unit and the static ring unit are made of 42CrMo materials, and the maintenance cost is reduced. And the service life of the coal mill is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of coal mills, and in particular to a wear-resistant moving and stationary ring structure of a medium-speed coal mill. Background Art

[0002] Medium-speed coal mill refers to a coal mill with an operating speed of 50 to 300 r / min. It is widely used in pulverizing systems in the power, metallurgy, building materials, chemical and other industries, especially in blast furnace coal injection pulverizing systems that require a large amount of coal.

[0003] When the medium-speed coal mill is working, the raw coal enters the center of the grinding disc through the coal drop pipe, the motor drives the moving disc to rotate through the reducer, and the moving disc drives the grinding disc to rotate synchronously. The raw coal in the center of the grinding disc moves to the edge under the action of centrifugal force, and the grinding roller crushes and grinds the raw coal under the action of hydraulic device or other external force to form coal powder; the ground coal powder is blown from the edge of the grinding disc by hot air and brought into the separator for separation. In the separator, the coal powder that meets the fineness requirements is sent to the boiler for combustion, while the coarse powder that does not meet the requirements returns to the grinding disc for continued grinding until it reaches the qualified fineness.

[0004] The existing medium-speed coal mill dynamic and static ring materials have poor wear resistance. The dynamic and static rings are subjected to the erosion of primary air, coal powder and impurities for a long time. The dynamic circulation channel and sealing plate of the coal mill are prone to wear. The increase in the gap will increase the primary air leakage rate and reduce the primary air efficiency. The existing coal mill has a pebble coal emission of 1.5t / h. There is ash leakage during emission, which causes serious pollution to the zero-meter environment of the boiler. At the same time, the dynamic and static rings and sealing plates of the coal mill are also worn, resulting in changes in the internal flow field of the coal mill, causing serious blowing damage to the coal mill barrel wall and other structures of the roller bracket, affecting the safe operation of the equipment. Summary of the invention

[0005] In order to increase the service life of a coal mill, the present application provides a wear-resistant moving and stationary ring structure of a medium-speed coal mill.

[0006] The present application provides a wear-resistant medium-speed coal mill moving and stationary ring structure adopts the following technical solution:

[0007] A wear-resistant medium-speed coal mill dynamic and static ring structure, comprising: a static ring assembly, a dynamic ring assembly, a coal mill housing and a tray; the tray is arranged in the inner cavity of the coal mill housing, the dynamic ring assembly is fixedly arranged on the tray, and the dynamic ring assembly can rotate together with the tray; the static ring assembly is fixedly connected to the inner wall of the coal mill housing, and the static ring assembly is arranged along the circumference of the dynamic ring assembly;

[0008] The stationary ring assembly comprises a stationary ring unit, a stationary ring support plate bracket, and a stationary ring support plate bracket seat; a plurality of stationary ring support plate brackets are evenly distributed along the circumference of the inner wall of the coal mill housing, the stationary ring support plate bracket seat is annular, and the stationary ring support plate bracket seat is fixedly arranged on the top of the stationary ring support plate bracket, and the stationary ring support plate bracket seat is used to support the stationary ring unit;

[0009] The multiple sections of the stationary ring units are connected end to end in sequence, and the multiple sections of the stationary ring units form a closed circular ring.

[0010] In a possible implementation, the tray includes a supporting portion and a supporting portion that are integrally arranged, the supporting portion is coaxially arranged in the circumference of the supporting portion, an accommodating cavity is arranged between the supporting portion and the supporting portion, a grinding disc is arranged in the accommodating cavity, the grinding disc is coaxially fixedly connected to the top wall of the supporting portion, and the grinding disc is used to grind raw coal.

[0011] In a possible implementation, the stationary ring unit includes a horizontal portion and a vertical portion, the horizontal portion and the vertical portion are integrally arranged, the side wall of the vertical portion is fixedly connected to the inner wall of the coal mill housing, and the horizontal portion is mounted on the top wall of the stationary ring support plate bracket.

[0012] In a possible implementation, the stationary ring assembly further includes a stationary ring pressure block, which is fixedly disposed on the top wall of the horizontal portion and is bolted to the horizontal portion.

[0013] In a possible implementation, the dynamic ring assembly includes a plurality of dynamic ring units, the plurality of dynamic ring units are connected end to end in sequence, and the plurality of dynamic ring units form a closed circular ring, and the dynamic ring units are fixedly connected to the top wall of the supporting portion.

[0014] In a possible implementation, the material of the stationary ring unit and the dynamic ring unit are both set to 42CrMo.

[0015] In a possible implementation, a wear-resistant surfacing layer is provided on the surface of the stationary ring unit and the surface of the dynamic ring unit.

[0016] In a possible implementation, an air duct is provided on the dynamic ring unit, the air duct penetrates the dynamic ring unit in a vertical direction, and an angle a between an air inlet direction of the air duct and an axial direction of the dynamic ring assembly is set to be between 55° and 85°.

[0017] The present application includes at least one of the following beneficial technical effects:

[0018] 1. Through the wear-resistant medium-speed coal mill dynamic and static ring structure provided by the present application, the dynamic and static rings are set as multiple sections of dynamic ring units and static ring units, which facilitates the rapid disassembly and assembly of the dynamic rings and static rings. When the coal mill is worn, only the severely worn static ring unit or dynamic ring unit needs to be replaced, avoiding the overall disassembly and assembly of the dynamic ring or static ring, saving maintenance time and cost.

[0019] 2. The dynamic ring unit and the static ring unit are set to 42CrMo material to improve the wear resistance of the dynamic ring unit and the static ring unit, thereby facilitating the improvement of the service life of the coal mill.

[0020] 3. A wear-resistant surfacing layer is provided on the surface of the stationary ring unit and the surface of the dynamic ring unit, thereby further improving the wear resistance of the dynamic ring unit and the stationary ring unit, thereby increasing the service life of the coal mill.

[0021] 4. The angle a between the air inlet direction of the air duct and the axial direction of the moving ring assembly is set to between 55° and 85°, which reduces the resistance of the airflow of hot air mixed with coal powder, reduces energy loss, increases the ability of hot air to carry coal powder, and improves the powder discharge efficiency. At the same time, it can also reduce the erosion and wear of the coal mill housing, moving ring assembly and static ring assembly, and extend the service life of equipment components. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are used to provide a further understanding of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation to the present application.

[0023] Figure 1 It is a partial schematic diagram of the overall structure of a wear-resistant moving and stationary ring structure of a medium-speed coal mill in the present application.

[0024] Figure 2 It is a top view of the installation structure of a wear-resistant medium-speed coal mill moving and stationary ring structure of the present application.

[0025] Figure 3 It is a top view of the connection of the static ring unit of the wear-resistant medium-speed coal mill moving static ring structure of the present application.

[0026] Figure 4 It is a top view of the connection between the moving ring unit of the moving and stationary ring structure of a wear-resistant medium-speed coal mill in the present application.

[0027] Description of the drawings: 1. Stationary ring assembly; 11. Stationary ring unit; 111. Horizontal portion; 112. Vertical portion; 12. Stationary ring support plate bracket; 13. Stationary ring support plate bracket seat; 14. Stationary ring pressure block; 2. Moving ring assembly; 21. Moving ring unit; 211. Air duct; 3. Coal mill housing; 4. Tray; 41. Supporting portion; 42. Supporting portion; 43. Accommodating chamber; 5. Grinding disc. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0029] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features; in the description of this application, unless otherwise specified, "plurality" means two or more.

[0030] The following is combined with Figure 1 This application is described in further detail.

[0031] The embodiments of the present application disclose a wear-resistant moving and stationary ring structure of a medium-speed coal mill.

[0032] Reference Figure 1 A wear-resistant medium-speed coal mill dynamic and static ring structure comprises: a static ring assembly 1, a dynamic ring assembly 2, a coal mill housing 3 and a tray 4; the tray 4 is arranged in the inner cavity of the coal mill housing 3, the dynamic ring assembly 2 is fixedly arranged on the tray 4, and the dynamic ring assembly 2 can rotate together with the tray 4; the tray 4 comprises an integrally arranged supporting portion 41 and a supporting portion 42, the supporting portion 41 is coaxially arranged in the circumference of the supporting portion 42, an accommodating cavity 43 is arranged between the supporting portion 41 and the supporting portion 42, a grinding disc 5 is arranged in the accommodating cavity 43, the grinding disc 5 is coaxially fixedly connected to the top wall of the supporting portion 42, a roller is arranged on the grinding disc 5, and the raw coal is ground into coal powder by the grinding roller in the roller; the static ring assembly 1 is fixedly connected to the inner wall of the coal mill housing 3, and the static ring assembly 1 is arranged along the circumference of the dynamic ring assembly 2.

[0033] Reference Figure 1 and Figure 2The stationary ring assembly 1 includes a stationary ring unit 11, a stationary ring support plate bracket 12, a stationary ring support plate bracket seat 13 and a stationary ring pressure block 14; multiple stationary ring support plate brackets 12 are evenly distributed along the circumference of the inner wall of the coal mill housing 3, the stationary ring support plate bracket seat 13 is annular, and the stationary ring support plate bracket seat 13 is fixedly arranged on the top of the stationary ring support plate bracket 12, and the stationary ring support plate bracket seat 13 is used to support the stationary ring unit 11. The stationary ring unit 11 includes a horizontal portion 111 and a vertical portion 112. The horizontal portion 111 and the vertical portion 112 are integrally arranged. The side wall of the vertical portion 112 is fixedly connected to the inner wall of the coal mill housing 3. The horizontal portion 111 is mounted on the top wall of the stationary ring support plate bracket 13. The stationary ring pressure block 14 is fixedly arranged on the top wall of the horizontal portion 111. The stationary ring pressure block 14 is bolted to the horizontal portion 111. The multiple-section stationary ring units 11 are connected end to end in sequence, and the multiple-section stationary ring units 11 form a closed circular ring.

[0034] Reference Figure 2 and Figure 3 The moving ring assembly 2 is coaxially arranged on the inner ring of the stationary ring assembly 1, and the gap between the moving ring assembly 2 and the stationary ring assembly 1 is controlled below 8 mm, so as to avoid large-particle coal powder leaking from the gap between the stationary ring assembly 1 and the moving ring assembly 2 when grinding the raw coal, thereby improving the grinding quality of the raw coal.

[0035] Reference Figure 1 and Figure 4 The dynamic ring assembly 2 includes a plurality of dynamic ring units 21, which are connected end to end in sequence, and the plurality of dynamic ring units 21 form a closed circular ring, and the dynamic ring unit 21 is fixedly connected to the top wall of the support portion 42; a plurality of air ducts 211 are arranged on the dynamic ring unit 21, and the air ducts 211 penetrate the dynamic ring unit 21 in the vertical direction, and the plurality of air ducts are evenly distributed along the circumference of the dynamic ring assembly, and an angle a between the air inlet direction of the air duct 211 and the axial direction of the dynamic ring assembly 2 is between 55° and 85°; when the coal mill is working, the dynamic ring assembly 2 rotates with the tray 4, and the air duct 211 arranged on the dynamic ring unit 21 rotates synchronously, and hot air is blown upward from the bottom of the air duct 211, and a spiral upward airflow is formed under the action of the rotating dynamic ring assembly 2, and the ground coal powder is blown to the separator above the coal mill.

[0036] In particular, the material of the stationary ring unit 11 and the dynamic ring unit 21 are both set to 42CrMo, and the stationary ring unit 11 and the dynamic ring unit 21 are both processed in the form of casting, and the surfaces of the stationary ring unit 11 and the dynamic ring unit 21 are both provided with wear-resistant surfacing layers to improve the wear resistance of the static and dynamic ring structures and extend the service life of the equipment; multiple stationary ring units 11 or multiple dynamic ring units 21 can be connected by bolts, slots, or pins, as long as a fixed and detachable connection can be achieved between multiple stationary ring units 11 or multiple dynamic ring units 21.

[0037] The implementation principle of the wear-resistant medium-speed coal mill dynamic and static ring structure of the present application is as follows: when the raw coal is ground, the raw coal enters the grinding disc 5 through the coal drop pipe of the coal mill, the tray 4 drives the grinding disc 5 and the dynamic ring assembly 2 to rotate together, and the raw coal on the grinding disc 5 moves radially toward the periphery of the grinding disc 5 under the action of centrifugal force, and evenly enters the roller set on the grinding disc 5. The rotation of the grinding disc 5 drives the grinding roller to rotate, and the raw coal is squeezed and ground between the grinding roller and the grinding disc 5, and is crushed into coal powder. While grinding, hot air is blown upward from the bottom of the air duct 211, and the ground coal powder is blown up from the edge of the grinding disc 5 by the hot air and enters the separator for separation. Qualified coal powder enters the coal powder bin through the separator, and coal powder that does not meet the requirements returns to the grinding disc 5 for further grinding. The hot air spirals upward from bottom to top under the action of the rotation of the moving ring assembly 2, and contacts the inner wall of the coal mill housing 3 after spirally rising for a distance. In the area where the hot air mixed with coal powder spirally rises, the angle a between the flow direction of the air duct 211 and the axis of the moving ring assembly 2 is set to be between 55°-85°, which is convenient for reducing the resistance of the air flow of the hot air mixed with coal powder, reducing energy loss, and increasing the ability of the hot air to carry coal powder, thereby improving the powder discharge efficiency. At the same time, it can also reduce the scouring and wear of the coal mill housing 3, the moving ring assembly 2 and the static ring assembly 1, and extend the service life of the equipment components. Multiple static ring units 11 are connected end to end in sequence to form a closed circular ring to seal the moving ring assembly 2, so as to prevent large-particle coal powder from falling from the edge of the moving ring assembly 2. At the same time, multiple moving ring units 21 are connected end to end in sequence to form a closed circular ring, so that the air duct 211 set on the moving ring unit 21 blows hot air to form a wind field, which is convenient for evenly blowing the coal powder, thereby improving the grinding quality of the coal powder.

[0038] During installation and disassembly, the dynamic ring unit 21 and the static ring unit 11 can be transported, installed and disassembled in sections, saving a lot of manpower, materials and time; when the coal mill is worn, only the severely worn static ring unit 11 or the dynamic ring unit 21 needs to be replaced, avoiding the overall disassembly of the dynamic ring or the static ring, saving maintenance time and cost; at the same time, the material of the dynamic ring unit 21 and the static ring unit 11 is set to 42CrMo, and a wear-resistant surfacing layer is added to the surface, which improves the wear resistance of the dynamic ring unit 21 and the static ring unit 11, thereby facilitating the increase of the service life of the coal mill.

[0039] The above embodiments are only used to illustrate the technical solution of the present application, but not to limit it. The present application is not limited to the exact structure described above and illustrated in the accompanying drawings, and it cannot be determined that the specific implementation of the present application is limited to these descriptions. For ordinary technicians in the technical field to which the present application belongs, various changes and modifications made without departing from the concept of the present application should be deemed to belong to the protection scope of the present application.

Claims

1. A wear-resistant medium-speed coal mill moving and stationary ring structure, characterized in that: include: A stationary ring assembly (1), a dynamic ring assembly (2), a coal mill housing (3) and a tray (4); the tray (4) is arranged in the inner cavity of the coal mill housing (3), the dynamic ring assembly (2) is fixedly arranged on the tray (4), and the dynamic ring assembly (2) can rotate together with the tray (4); the stationary ring assembly (1) is fixedly connected to the inner wall of the coal mill housing (3), and the stationary ring assembly (1) is arranged along the circumference of the dynamic ring assembly (2); The stationary ring assembly (1) comprises a stationary ring unit (11), a stationary ring support plate bracket (12), and a stationary ring support plate bracket seat (13); a plurality of stationary ring support plate brackets (12) are evenly distributed along the circumference of the inner wall of the coal mill housing (3); the stationary ring support plate bracket seat (13) is annular, and the stationary ring support plate bracket seat (13) is fixedly arranged on the top of the stationary ring support plate bracket (12); the stationary ring support plate bracket seat (13) is used to support the stationary ring unit (11); The multiple sections of the stationary ring unit (11) are connected end to end in sequence, and the multiple sections of the stationary ring unit (11) form a closed circular ring.

2. The wear-resistant moving and stationary ring structure of a medium-speed coal mill according to claim 1, characterized in that: The tray (4) comprises a supporting portion (41) and a supporting portion (42) which are integrally arranged, the supporting portion (41) being coaxially arranged in the circumferential direction of the supporting portion (42), an accommodating cavity (43) being arranged between the supporting portion (41) and the supporting portion (42), a grinding disc (5) being arranged in the accommodating cavity (43), the grinding disc (5) being coaxially fixedly connected to the top wall of the supporting portion (42), and the grinding disc (5) being used for grinding raw coal.

3. The wear-resistant moving and stationary ring structure of a medium-speed coal mill according to claim 1, characterized in that: The stationary ring unit (11) comprises a horizontal portion (111) and a vertical portion (112); the horizontal portion (111) and the vertical portion (112) are integrally arranged; a side wall of the vertical portion (112) is fixedly connected to an inner side wall of the coal mill housing (3); and the horizontal portion (111) is mounted on a top wall of the stationary ring support plate bracket (13).

4. The wear-resistant moving and stationary ring structure of a medium-speed coal mill according to claim 2, characterized in that: The stationary ring assembly further comprises a stationary ring pressure block (14), wherein the stationary ring pressure block (14) is fixedly arranged on the top wall of the horizontal portion (111), and the stationary ring pressure block (14) is bolted to the horizontal portion (111).

5. The wear-resistant moving and stationary ring structure of a medium-speed coal mill according to claim 2, characterized in that: The dynamic ring assembly (2) comprises a plurality of dynamic ring units (21), the plurality of dynamic ring units (21) being connected end to end in sequence, and the plurality of dynamic ring units (21) forming a closed circular ring, and the dynamic ring units (21) being fixedly connected to the top wall of the supporting portion (41).

6. The wear-resistant moving and stationary ring structure of a medium-speed coal mill according to claim 5, characterized in that: The material of the stationary ring unit (11) and the dynamic ring unit (21) is both set to 42CrMo.

7. The wear-resistant moving and stationary ring structure of a medium-speed coal mill according to claim 5, characterized in that: The surface of the stationary ring unit (11) and the surface of the dynamic ring unit (21) are both provided with a wear-resistant cladding layer.

8. The wear-resistant moving and stationary ring structure of a medium-speed coal mill according to claim 5, characterized in that: The dynamic ring unit (21) is provided with an air duct (211), the air duct (211) vertically passes through the dynamic ring unit (21), and an angle a between an air inlet direction of the air duct (211) and an axial direction of the dynamic ring assembly (2) is set to be between 55° and 85°.

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