Wear-resistant split type movable and static rings capable of improving output of coal mill and design method of wear-resistant split type movable and static rings

Abstract

The invention discloses a wear-resistant split-type dynamic and static ring capable of improving the output of a coal mill and a design method thereof, the wear-resistant split-type dynamic and static ring comprises a cylinder wall, a split-type dynamic ring and a split-type static ring, the split-type static ring is fixed on the inner wall of the cylinder wall, the cylinder wall and the split-type static ring are connected through a fastener I, and the bottom end of the cylinder wall is connected with round steel for constructing a supporting structure. The cylinder wall is connected with the flange through a first fastener, a base is fixed to the bottom of the split type static ring, the base is connected with the cylinder wall through a first fastener, the split type moving ring is installed on the outer side of the millstone and moves along with rotation of the millstone, and the split type moving ring and the millstone are fixed through a second fastener. And blades are arranged on the split moving ring. Through the split multi-block design of the movable and static rings, the weight is reduced, the wear resistance of the through-flow surfaces of the movable and static rings can be improved, and the service life is prolonged; maintenance and replacement are facilitated, and maintenance work efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of coal mills, and in particular to a wear-resistant split dynamic and static ring capable of improving the output of a coal mill and a design method thereof. Background Art

[0002] The boiler efficiency of coal-fired units is the main factor affecting the coal consumption of the units, and the pulverizing system is an important auxiliary system of the boiler island of coal-fired units. Its operation directly affects the boiler combustion performance, boiler efficiency and safe and economical operation. In recent years, the safe and economical operation of coal-fired power plants has been affected by factors such as the reduced consistency between the characteristics of the coal used and the designed coal type and the large fluctuations in the unit load rate. The production level and standards of the existing pulverizing system can no longer meet the safe, environmentally friendly and economical operation of the boiler.

[0003] The internal flow field of the coal mill is one of the key factors affecting the efficiency of the pulverizing system, mainly including the upper flow field of the coal mill involving the separator flow field, the middle flow field involving the flow field above the coal mill disc and below the separator, and the lower flow field involving the coal mill inlet air duct and the dynamic and static ring parts. In view of the problems of insufficient coal mill output, coarse coal powder fineness, and poor uniformity index, the actual coal quality entering the furnace deviates greatly from the design value, resulting in insufficient grinding output and ventilation output. The overall grinding output and ventilation output of the coal mill are insufficient. The output of a single machine is insufficient under high load, and the standby mill must be activated. Long-term operation brings safety hazards to the operation and maintenance of the coal mill. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a wear-resistant split dynamic and static ring and a design method thereof that can improve the output of a coal mill, which can improve the wear resistance of the flow surface of the dynamic and static rings and extend the service life; facilitate maintenance and replacement, improve maintenance work efficiency; and improve the fineness and uniformity of coal powder.

[0005] On the one hand, the purpose of the present invention is achieved as follows: a wear-resistant split dynamic and static ring that can improve the output of a coal mill comprises a cylinder wall, a split dynamic ring and a split static ring, wherein the split static ring is fixed on the inner wall of the cylinder wall, the cylinder wall and the split static ring are connected by a fastener 1, a round steel is connected to the bottom end of the cylinder wall for constructing a supporting structure, the cylinder wall is connected to a flange by a fastener 1, a base is fixed to the bottom of the split static ring, and the base is connected to the cylinder wall by a fastener 1, the split dynamic ring is installed on the outside of the grinding disc and moves with the rotation of the grinding disc, and the split dynamic ring is fixed to the grinding disc by a fastener 2; blades are arranged on the split dynamic ring.

[0006] As a further limitation of the present invention, the fastener 1 is a bolt 1, and the bolt 1 is fastened by penetrating the threaded hole of the split static ring from the outside of the cylinder wall through the bolt head.

[0007] As a further limitation of the present invention, the second fastener is a second bolt, and the split dynamic ring and the grinding disc are fixed by the second bolt.

[0008] As a further limitation of the present invention, an air gap seal is formed between the split dynamic ring and the split static ring, and a gap is left.

[0009] In order to facilitate maintenance and replacement, save maintenance time and reduce operating costs, the split static ring adopts a split structure, and the inner cavity of the split static ring is a detachable grinding plate.

[0010] As a further limitation of the present invention, the split static ring is connected to the base via high-strength bolts.

[0011] As a further limitation of the present invention, the split moving ring adopts a split structure, and multiple moving rings are connected by mortise and tenon structures.

[0012] In order to reduce the vortex generated by the sharp corners, help the airflow to flow more evenly upward into the channel, improve the output, and make the wear of the dynamic and static rings more uniform, the lower end of the blade uses a guide streamline design.

[0013] Another aspect of the present invention is to achieve the purpose of: a design method for a wear-resistant split dynamic and static ring capable of improving the output of a coal mill, comprising the following steps: 1) The static ring adopts a split structure: there are 24 static rings per coal mill, the inner cavity of the static ring is a detachable anti-wear plate, the static ring base is a 16Mn welded assembly, each set has four pieces, and the base is heat treated to relieve stress; 2) The dynamic ring adopts a split structure: there are 14 dynamic rings per coal mill, and each dynamic ring is connected by a mortise and tenon structure. All the flow surfaces of the dynamic ring are clad with cobalt-tungsten alloy powder with a thickness of ≥500μm and a hardness of ≥HV1000; 3) Dynamic ring blade design: The blade height is 270mm, the inclination angle is 45°, and the lower end of the blade uses a guide streamline design. The blade consists of four arcs with radii of 60mm, 80mm, 100mm, and 290mm respectively.

[0014] As a further limitation of the present invention, an air gap seal is formed between the dynamic ring and the static ring, and a gap is left between the dynamic ring and the static ring, and the gap size is 12.7mm±0.5; the static ring height is 530mm, the dynamic ring height is 290mm, the blade height is 270mm, the thickness is 100mm, and the grinding disc diameter is 3168mm.

[0015] The present invention adopts the above technical scheme, and compared with the prior art, the beneficial effects are as follows: the dynamic and static rings of the present invention are designed with multiple blocks, which reduces weight, can improve the wear resistance of the dynamic and static ring flow surfaces, and extend the service life; it is easy to repair and replace, and improves the efficiency of maintenance work; the new blade structure has a better flow field under all working conditions, which can effectively reduce the resistance of the primary air, and will obtain lower unit consumption and greater output. Compared with ordinary products, it can effectively improve the ventilation output and reduce resistance, and realize low-cost, safe and stable operation of the coal mill. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic structural diagram of the split dynamic and static ring of the present invention.

[0017] Figure 2 It is a partial schematic diagram of the split dynamic and static ring of the present invention.

[0018] Figure 3 It is an axonometric view of the split dynamic and static ring of the present invention.

[0019] Figure 4 It is a schematic diagram of the structure of a single split dynamic ring of the present invention.

[0020] Figure 5 It is a schematic diagram of the structure of a single split static ring of the present invention.

[0021] Figure 6 It is the structural dimension diagram of the dynamic and static rings of the present invention.

[0022] Figure 7 It is a structural dimension diagram of the dynamic and static ring blades of the present invention.

[0023] Among them, 1 is the cylinder wall, 2 is the split static ring, 3 is the bolt one, 4 is the round steel, 5 is the flange, 6 is the base, 7 is the split dynamic ring, 8 is the bolt two, 9 is the grinding disc, and 10 is the blade. DETAILED DESCRIPTION

[0024] like Figure 1-3The wear-resistant split dynamic and static ring for improving the output of the coal mill shown in the figure comprises a cylinder wall 1, a split dynamic ring 7 and a split static ring 2. The cylinder wall 1 surrounds the internal space of the entire coal mill. The split static ring 2 is fixed on the inner wall of the cylinder wall 1. The cylinder wall 1 and the split static ring 2 are connected by a tightening bolt 3. The bolt 3 passes through the threaded hole of the split static ring 2 from the outside of the cylinder wall 1 through the bolt head for tightening. The bottom end of the cylinder wall 1 is connected to a round steel 4 for constructing a supporting structure to make the overall structure of the coal mill The structure is more stable. The cylinder wall 1 is connected to the flange 5 by bolts 1-3 to ensure that the connection between the coal mill and the outside is stable. The bottom of the split static ring 2 is fixed with a base 6, which is connected to the cylinder wall 1 by tightening bolts 1-3 to support the weight of the entire coal mill and bear its weight and vibration during operation. The split dynamic ring 7 is installed on the outside of the grinding disc 9 and moves with the rotation of the grinding disc 9. The split dynamic ring 7 and the grinding disc 9 are fixed by bolts 2-8; blades 10 are arranged on the split dynamic ring 7. An air gap seal is formed between the split dynamic ring 7 and the split static ring 2, and a gap is left; the split static ring 2 adopts a split structure, and the inner cavity of the split static ring 2 is a detachable grinding plate; the split static ring 2 is connected to the base 6 by high-strength bolts; the split dynamic ring 7 adopts a split structure, and multiple dynamic rings are connected by mortise and tenon structures; the lower end of the blade 10 uses a guide streamline design.

[0025] A design method for a wear-resistant split dynamic and static ring capable of improving the output of a coal mill comprises the following steps: like Figure 4 As shown, 1) The static ring adopts a split structure: there are 24 static rings per coal mill, which are easy to install and replace. The material is high-chromium white cast iron (KmTBCr20NiMoCu), and the heat treatment hardness is HRC55~63; the inner cavity of the static ring is a detachable anti-wear plate, which is convenient for maintenance and replacement, saving maintenance time and reducing operating costs; the static ring base is a 16Mn welded assembly, each set has four pieces, and the base is heat treated to relieve stress; like Figure 5 As shown, 2) The dynamic ring adopts a split structure: there are 14 dynamic rings per coal mill, made of rare earth alloy material ZG40CrMnMoNiSiRe, with a heat treatment hardness of HRC38~42, and each dynamic ring is connected by a mortise and tenon structure. All the flow surfaces of the dynamic ring are clad with cobalt-tungsten alloy powder WC-10Co-4Cr, with a thickness of ≥500μm and a hardness of ≥HV1000; like Figure 6-7 As shown, 3) Dynamic ring blade design: the blade height is 270mm, the inclination angle is 45°, the lower end of the blade uses a guide streamline design, the blade consists of four arcs, and the radii are 60mm, 80mm, 100mm, and 290mm respectively; it can reduce the vortex caused by sharp corners, help the airflow to flow more evenly upward into the channel, improve ventilation output, and make the wear of the dynamic and static rings more uniform.

[0026] An air gap seal is formed between the dynamic ring and the static ring, and a gap is left between the dynamic ring and the static ring, the gap size is 12.7mm±0.5; the static ring height is 530mm, the dynamic ring height is 290mm, the blade height is 270mm, the thickness is 100mm, and the grinding disc diameter is 3168mm. In actual operation, there is no sticking and wear between the dynamic and static rings, and it is not easy for debris to get stuck. The easily worn parts of the dynamic and static rings can be easily inspected and replaced, and the wear-resistant layer can be repaired without disassembling the coal mill roller assembly components; When the present invention is working, the split static ring is fixed on the inner side of the wall of the coal mill and remains motionless, and the split dynamic ring is connected to the grinding disc, moves with the rotation of the grinding disc, and can move relative to the static ring. The feeding system of the coal mill feeds the raw coal into the interior of the coal mill. After the coal powder enters the coal mill, it first falls on the surface of the grinding disc. The grinding disc and the grinding roller rotate, so that the coal powder is compressed and sheared in the contact area between the grinding disc and the grinding roller. These forces grind the coal powder into fine powder. The wear during the grinding process mainly occurs on the contact surface of the grinding disc and the grinding roller. The coal powder ground into fine powder spirals up from the gap between the dynamic ring and the static ring under the action of primary wind force, and is sent to the combustion equipment or other processing systems through the discharge system of the coal mill.

[0027] The present invention provides a wear-resistant split dynamic and static ring and a design method thereof that can improve the output of a coal mill. The dynamic and static rings are designed to be split into multiple pieces to reduce weight, thereby improving the wear resistance of the flow surfaces of the dynamic and static rings and extending their service life. The design is convenient for maintenance and replacement, thereby improving maintenance efficiency. The novel blade structure has a better flow field under all working conditions, and can effectively reduce the resistance of primary air, thereby obtaining lower unit consumption and greater output. Compared with ordinary products, the design can effectively improve ventilation output and reduce resistance, thereby achieving low-cost, safe and stable operation of the coal mill.

[0028] The present invention is not limited to the above-mentioned embodiments. On the basis of the technical solution disclosed in the present invention, technicians in this field can make some substitutions and deformations to some technical features therein according to the disclosed technical content without creative labor, and these substitutions and deformations are all within the protection scope of the present invention.

Claims

1. A wear-resistant split dynamic and static ring capable of improving the output of a coal mill, comprising a cylinder wall (1), a split dynamic ring (7) and a split static ring (2), characterized in that: A split static ring (2) is fixed on the inner wall of the cylinder wall (1), the cylinder wall (1) and the split static ring (2) are connected by a fastener 1, a round steel (4) is connected to the bottom end of the cylinder wall (1) for constructing a support structure, the cylinder wall (1) is connected to a flange (5) by a fastener 1, a base (6) is fixed to the bottom of the split static ring (2), the base (6) is connected to the cylinder wall (1) by a fastener 1, the split dynamic ring (7) is installed on the outer side of the grinding disc (9), moves with the rotation of the grinding disc (9), and the split dynamic ring (7) is fixed to the grinding disc (9) by a fastener 2; and blades (10) are arranged on the split dynamic ring (7).

2. The wear-resistant split dynamic and static ring capable of improving the output of a coal mill according to claim 1, characterized in that: The fastener one is a bolt one (3), and the bolt one (3) is fastened by passing the bolt head from the outside of the cylinder wall (1) into the threaded hole of the split static ring (2).

3. The wear-resistant split dynamic and static ring capable of improving the output of a coal mill according to claim 1, characterized in that: The second fastener is a second bolt (8), and the split moving ring (7) and the grinding disc (9) are fixed by the second bolt (8).

4. The wear-resistant split dynamic and static ring capable of improving the output of a coal mill according to claim 1, characterized in that: An air gap seal is formed between the split dynamic ring (7) and the split static ring (2), and a gap is left.

5. The wear-resistant split dynamic and static ring capable of improving the output of a coal mill according to claim 1, characterized in that: The split static ring (2) adopts a split structure, and the inner cavity of the split static ring (2) is a detachable grinding plate.

6. The wear-resistant split dynamic and static ring capable of improving the output of a coal mill according to claim 5, characterized in that: The split static ring (2) is connected to the base (6) via high-strength bolts.

7. The wear-resistant split dynamic and static ring capable of improving the output of a coal mill according to claim 1, characterized in that: The split type moving ring (7) adopts a split type structure, and a plurality of moving rings are connected by a mortise and tenon structure.

8. The wear-resistant split dynamic and static ring capable of improving the output of a coal mill according to claim 1, characterized in that: The lower end of the blade (10) adopts a flow guide streamline design.

9. A design method for a wear-resistant split dynamic and static ring capable of improving the output of a coal mill, characterized in that: The following steps are involved: 1) The static ring adopts a split structure: there are 24 static rings per coal mill, the inner cavity of the static ring is a detachable anti-wear plate, the static ring base is a 16Mn welded assembly, each set has four pieces, and the base is heat treated to relieve stress; 2) The dynamic ring adopts a split structure: there are 14 dynamic rings per coal mill, and each dynamic ring is connected by a mortise and tenon structure. All the flow surfaces of the dynamic ring are clad with cobalt-tungsten alloy powder with a thickness of ≥500μm and a hardness of ≥HV1000; 3) Dynamic ring blade design: The blade height is 270mm, the inclination angle is 45°, and the lower end of the blade uses a guide streamline design. The blade consists of four arcs with radii of 60mm, 80mm, 100mm, and 290mm respectively.

10. The design method of the wear-resistant split dynamic and static ring capable of improving the output of the coal mill according to claim 9, characterized in that: An air gap seal is formed between the dynamic ring and the static ring, and a gap is left between the dynamic ring and the static ring, and the gap size is 12.7mm±0.5; the static ring height is 530mm, the dynamic ring height is 290mm, the blade height is 270mm, the thickness is 100mm, and the grinding disc diameter is 3168mm.

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