Method for repairing wear of a middle disc of a high-temperature fan for pellets

Abstract

The application discloses a kind of pellet high-temperature fan middle disc abrasion repair method, first identification middle disc abrasion part and adopt annular cutting of cutting, cut off middle disc abrasion part, make middle disc separate, the part of middle disc connected on main shaft is defined as first reserved middle disc, the part of middle disc connected blade is defined as second reserved middle disc;Using numerical control machine tool respectively on the outer circumferential surface of first reserved middle disc and the inner circumferential surface of second reserved middle disc is processed, according to the outer diameter size of first reserved middle disc and the inner diameter size of second reserved middle disc, repair middle disc of annular shape is made;Then repair middle disc is respectively welded with first reserved middle disc, second reserved middle disc fixed;After welding, carry out flaw detection treatment to weld joint;If weld joint meets the requirements, complete the repair of middle disc.The application is replaced by replacement repair mode to middle disc abrasion part, and the repaired middle disc meets the requirements, with high reliability, and compared with the traditional replacement of the whole impeller, greatly reduces the replacement maintenance cost.

Description

Technical Field

[0001] This invention belongs to the field of pellet production technology, specifically relating to a method for repairing the worn disc of a high-temperature blower in a pellet production line. Background Technology

[0002] In steel pelletizing production lines, the high-temperature blowers in the PHII section of the pelletizing plant operate at temperatures reaching 410±20℃. High-temperature multi-tube dust collectors are used for dust removal. Due to the inherent properties of multi-tube dust collectors, their dust removal efficiency is only between 80-90%. During production, residual high-temperature dust causes wear on the impeller of the blower rotor, especially the impeller's central disc, which experiences more severe wear during use. Currently, users of high-temperature, large-scale blowers in the industry can only restore the thickness of the impeller's central disc by welding on both sides. Extensive welding leads to uncontrollable deformation and creates significant welding stress. In practical applications, the central disc repair section is prone to cracking, potentially causing impeller runaway accidents. Because there is no reliable repair technology, the only option is to scrap the entire impeller and customize a new one, resulting in high replacement costs. Summary of the Invention

[0003] The purpose of this invention is to provide a highly reliable and low-cost repair method for the wear of the bearing disc in a high-temperature pellet fan.

[0004] The objective of this invention is achieved through the following technical solution: a method for repairing wear on the inner disc of a high-temperature pellet fan, characterized by comprising the following steps:

[0005] S1: Identify the worn part of the impeller's middle disk by centering the outer ring of the impeller and marking the annular cutting area on the middle disk so that the worn part of the middle disk is located within the annular cutting area;

[0006] S2: Use gas cutting to cut away the annular cutting area and separate the middle disk. The middle disk part connected to the main shaft is defined as the first retained middle disk, and the middle disk part connected to the blade is defined as the second retained middle disk.

[0007] S3: Use a CNC machine tool to machine the outer circumferential surface of the first retaining plate and the inner circumferential surface of the second retaining plate respectively, and record the outer diameter of the first retaining plate and the inner diameter of the second retaining plate after machining;

[0008] S4: Fabricate a ring-shaped repair disc based on the outer diameter of the first retained disc and the inner diameter of the second retained disc;

[0009] S5: First, put the repaired middle plate onto the first retained middle plate, first use argon arc welding for base positioning, and then use symmetrical staggered welding to weld the two together and fix them.

[0010] S6: Place the second retained middle plate onto the repaired middle plate, first use argon arc welding for base positioning, and then use symmetrical staggered welding to weld the two together and fix them in place;

[0011] S7: After welding, the weld is inspected for defects; if the weld meets the requirements, the wear of the middle plate of the high-temperature fan of the pellet plant is repaired; if there are problems with the weld, it is reworked until the weld meets the requirements.

[0012] Furthermore, a first wear-resistant plate is welded at the welding point between the repaired disc and the first retained disc, and a second wear-resistant plate is welded at the welding point between the repaired disc and the second retained disc.

[0013] Furthermore, the welding point corresponding to the repair plate is provided with a welding and centering bevel.

[0014] The beneficial effects of the present invention are: by using the solution of the present invention, the worn part of the middle disk is replaced by replacement and repair, the repaired middle disk meets the requirements, has high reliability, and greatly reduces the replacement and maintenance cost compared with the traditional method of replacing the entire impeller. Attached Figure Description

[0015] The present invention will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the present invention. For those skilled in the art, other drawings can be obtained based on the following drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the rotor structure of a high-temperature blower for pelletizing.

[0017] Figure 2 This is a schematic diagram of the structure for repairing the disk in this invention.

[0018] Figure 3 yes Figure 2 An enlarged schematic diagram of part A in the middle.

[0019] Figure 4 This is a schematic diagram of the structure of the repaired middle plate mounted on the rotor spindle.

[0020] Figure 5 yes Figure 4 Enlarged schematic diagram of part B. Detailed Implementation

[0021] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0022] This invention minimizes the cost of replacing the entire impeller by partially replacing the worn impeller disc. The repair method for worn impeller discs in high-temperature fans is as follows.

[0023] Step 1: Identify the worn part of the impeller's middle disk. Use the outer ring of the impeller to center the impeller and mark the annular cutting area on the middle disk so that the worn part of the middle disk is located within the annular cutting area.

[0024] Step 2: Use gas cutting to remove the annular cutting area and separate the middle plate. The middle plate part connected to the main shaft 100 is defined as the first retained middle plate 10, and the middle plate part connected to the blade is defined as the second retained middle plate 20. The middle plate part corresponding to the annular cutting area is scrapped.

[0025] Step 3: Use a CNC machine tool to machine the outer circumferential surface of the first retaining center plate 10 and the inner circumferential surface of the second retaining center plate 20 respectively, and record the outer diameter d1 of the first retaining center plate 10 and the inner diameter d2 of the second retaining center plate 20 after machining.

[0026] Step 4: Fabricate a ring-shaped repair plate 30 based on the outer diameter of the first retained plate and the inner diameter of the second retained plate. The inner diameter of the repair plate 30 is d3, where d1 ≤ d3 ≤ d1 + 2mm; the outer diameter of the repair plate 30 is d4, where d2 - 2mm ≤ d3 ≤ d2; a welding and centering inclined surface 301 is provided on the repair plate to improve centering accuracy and welding strength.

[0027] Step 5: First, attach the repaired middle plate 30 onto the first retained middle plate 10. Use argon arc welding for initial positioning, then weld the two together using symmetrical staggered welding. Next, attach the second retained middle plate 20 onto the repaired middle plate 30. Use argon arc welding for initial positioning, then weld the two together using symmetrical staggered welding. Preferably, a first wear-resistant plate 40 is welded to the weld between the repaired middle plate 30 and the first retained middle plate 10, and a second wear-resistant plate 50 is welded to the weld between the repaired middle plate 30 and the second retained middle plate 20. The connection and reinforcement using the first wear-resistant plate 40 and the second wear-resistant plate 50 improves strength and enhances wear resistance.

[0028] The specific welding operation requirements are:

[0029] 1. Before welding, clean the bevel and surrounding area of ​​oil, dust, and rust to keep the welding surface clean.

[0030] 2. TIG welding is used for the root pass, and both sides are welded to ensure full penetration and no porosity or cracks; the welding material is TIG-50 welding wire with a diameter of 2.4mm.

[0031] 3. Use CO2 gas shielded welding to fill and cover the surface, ensuring no porosity, slag inclusions, or cracks; use Atlantic CHT711 flux-cored welding wire with a diameter of 1.2mm.

[0032] 4. Weld on both sides at the appropriate time to prevent deformation.

[0033] Step 6: After welding, the weld is inspected for defects; if the weld meets the requirements, the wear of the middle plate of the high-temperature fan of the pellet plant is repaired; if there are problems with the weld, it is reworked until the weld meets the requirements.

[0034] The method of this invention was used to repair the middle plate of a high-temperature regenerating air fan in a steel plant's pelletizing unit. The cost was 15% of the cost of replacing the entire impeller. After 24 months of use, no defects such as cracks or severe wear were found during flaw detection. Moreover, the vibration and other indicators remained stable during use, demonstrating high reliability.

[0035] In summary, although the present invention has listed the above preferred embodiments, it should be noted that various changes and modifications can be made by those skilled in the art, and such changes and modifications should be included within the scope of protection of the present invention unless they deviate from the scope of the present invention.

Claims

1. A method for repairing wear on the disc of a high-temperature pelletizing fan, characterized in that, Includes the following steps: S1: Identify the worn part of the impeller's middle disk by centering the outer ring of the impeller and marking the annular cutting area on the middle disk so that the worn part of the middle disk is located within the annular cutting area; S2: Use gas cutting to remove the annular cutting area and separate the middle disk. The middle disk part connected to the main shaft is defined as the first retained middle disk, and the middle disk part connected to the blade is defined as the second retained middle disk. S3: Use a CNC machine tool to machine the outer circumferential surface of the first retaining plate and the inner circumferential surface of the second retaining plate respectively, and record the outer diameter of the first retaining plate and the inner diameter of the second retaining plate after machining; S4: Fabricate a ring-shaped repair disc based on the outer diameter of the first retained disc and the inner diameter of the second retained disc; S5: First, put the repaired middle plate onto the first retained middle plate, first use argon arc welding for base positioning, and then use symmetrical staggered welding to weld the two together and fix them. S6: Place the second retained middle plate onto the repaired middle plate, first use argon arc welding for base positioning, and then use symmetrical staggered welding to weld the two together and fix them in place; S7: After welding, the weld is inspected for defects; if the weld meets the requirements, the wear of the middle plate of the high-temperature fan of the pellet plant is repaired; if there are problems with the weld, it is reworked until the weld meets the requirements.

2. The method for repairing wear on the disc of a high-temperature pellet fan according to claim 1, characterized in that: A first wear-resistant plate is welded at the welding point between the repaired disc and the first retained disc, and a second wear-resistant plate is welded at the welding point between the repaired disc and the second retained disc.

3. The method for repairing wear on the disc of a high-temperature pellet fan according to claim 1 or 2, characterized in that: The welded joints corresponding to the repaired plate are equipped with welding and centering bevels.

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