Method for repairing crusher rack

Abstract

The invention belongs to the field of crusher rack repair, and relates to a crusher rack repair method which comprises the following steps: preheating: baking the periphery of a cracking part of a crusher rack, preheating a workpiece until the temperature of the cracking part on the surface of the workpiece reaches 150 DEG C, and taking the workpiece as the crusher rack; air gouging is conducted, specifically, layered gouging is conducted from the initial point of the crack through carbon rod air gouging till the deepest position of the crack is gouged; primary heat preservation is conducted, after gouging is completed, the gouging periphery of the workpiece is covered with lime, and then natural cooling is conducted; overlaying operation: layering overlaying until the overlaying height is higher than the surface of the workpiece before air gouging; and after secondary heat preservation and tempering are finished, the periphery of the welding position of the workpiece is wrapped with lime again. According to the method, online welding can be achieved, and the problem that the whole machine frame needs to be replaced when the machine frame of the crusher cracks is solved.

Description

Technical Field

[0001] The present invention belongs to the field of crusher frame repair and relates to a method for repairing a crusher frame. Background Art

[0002] For ore or stone enterprises, it is usually necessary to process large pieces of minerals into small pieces. For example, the underground crushers used in a certain mining industry, the surface cone crushers, and the crushers in a stone factory. These crushers all include an upper frame and a lower frame, collectively referred to as the crusher frame. The crusher frame is one of the important core components of the equipment. As the usage time increases, due to various reasons, the crusher frame may have early damage phenomena such as cracking, which is a major hidden danger for the crusher. In this case, it is generally chosen to replace the crusher frame to prevent further damage to other key components.

[0003] Taking the replacement of the lower frame of the crusher as an example:

[0004] When replacing the lower frame, the crusher needs to be completely disassembled, and all relevant components are removed from top to bottom, including but not limited to the aggregate bucket, fixed cone, moving cone, large gear ring, release cylinder, adjusting ring, spherical tile, counterweight assembly, eccentric bushing, upper frame assembly, horizontal shaft assembly, etc. Completing the removal of these components requires at least 4 people to work continuously for 7 days (8 hours per day). The remaining lower frame assembly and the main shaft after removal need to be returned to the factory for disassembly. After the new frame arrives, it also takes about 7 days for 4 people to reassemble all the components disassembled before, thus completing the replacement process of the entire lower frame. The entire work process takes a long time, about 75 days; at the same time, the overall cost is high, reaching 600,000 - 700,000 yuan. Summary of the Invention

[0005] The present application provides a method for repairing a crusher frame, which can achieve on-line welding and solve the problem of replacing the entire frame when the crusher frame cracks.

[0006] To achieve the above technical purpose, the technical solution adopted by the present application is a method for repairing a crusher frame, including:

[0007] Preheating: Bake the periphery of the cracked part of the crusher frame, and preheat the workpiece until the temperature at the crack on the workpiece surface reaches 150°C. The workpiece is the crusher frame; Gouging, use carbon rod gouging to layer and gouge from the starting point of the crack until reaching the deepest part of the crack;

[0008] Primary heat preservation: After gouging is completed, cover the gouged periphery of the workpiece with lime and then let it cool naturally;

[0009] Surfacing operation: Layer surfacing until the surfacing height is higher than the workpiece surface before gouging;

[0010] Secondary heat preservation and tempering: After welding is completed, the welded position of the workpiece is wrapped with lime again around its perimeter.

[0011] As an improved technical solution of this application, the thickness of each layer of gouging during the gouging process is between 2 - 4 mm.

[0012] As an improved technical solution of this application, the covering thickness of lime during the primary heat preservation process is greater than 100 mm.

[0013] As an improved technical solution of this application, during the surfacing operation, the height of each layer of surfacing is between 3 - 5 mm.

[0014] As an improved technical solution of this application, the covering thickness of lime during the secondary heat preservation and tempering process is greater than 100 mm.

[0015] As an improved technical solution of this application, the judgment basis for the gouging to reach the deepest part of the crack is that the gouging sound changes, or obvious metallic luster appears, or the detection result of the flaw detector.

[0016] Beneficial effects

[0017] This application improves the repair method of the crusher frame, uses on - line repair instead of demolition repair, solves the problem that the whole frame usually needs to be replaced when the crusher frame cracks; effectively shortens the maintenance period and maintenance cost; and at the same time reduces the on - site safety hazards. Description of the drawings

[0018] Figure 1 Show the top - view structure schematic diagram of the lower frame of the crusher;

[0019] Figure 2 Show the actual on - site picture of the cracked part of the lower frame of the HP500 crusher;

[0020] Figure 3 Show the actual on - site picture of the cracked part of the lower frame of the HP500 crusher after gouging;

[0021] Figure 4 Show the actual on - site picture of the cracked part of the lower frame of the HP500 crusher after gouging and surfacing;

[0022] Figure 5 Show the actual on - site picture of the lime heat preservation at the cracked part of the lower frame of the HP500 crusher;

[0023] In the figure, 1. Inner ring for installing the main shaft of the lower - frame foundation support rib, 2. Inner ring for installing the main shaft, 3. Lower - frame assembly, 4. Horizontal shaft, 5. Cracking part of the foundation support rib. Detailed implementation manners

[0024] The crusher frame is a spare part that houses the main - shaft ring and has three foundation support ribs. It is an overall steel casting, with dimensions of approximately 2 meters in diameter and 1 meter in height.

[0025] For large workpieces, there are two major risks during welding: one is that cracks are difficult to be completely welded; the other is that the workpiece may deform or the internal stress may change during the welding process, which may lead to secondary cracking. At the same time, for integrally cast steel parts, it is difficult to perform ideal tempering treatment after welding. If the treatment is improper, it is easy to have the situation that the residual stress is not completely eliminated, resulting in cracks or fragmentation of the subsequent workpiece; considering that the crusher vibrates greatly during operation and is often impacted by massive ores or ironware, improper treatment will reduce the durability of the equipment.

[0026] A repair method for a crusher frame includes:

[0027] Preheating: Bake the periphery of the cracked part of the crusher frame, and preheat the workpiece until the temperature at the crack on the workpiece surface reaches 150 °C. The workpiece is the crusher frame. Preheating the workpiece can reduce the hardness of the steel to improve the air gouging efficiency and reduce defects such as cracks and deformation generated during the air gouging process.

[0028] Air gouging: Use a carbon rod for air gouging to perform layered gouging starting from the crack starting point until the deepest part of the crack is reached;

[0029] Primary heat preservation: After air gouging is completed, cover the periphery of the workpiece after air gouging with lime and then let it cool naturally;

[0030] Surfacing operation: Perform layered surfacing until the surfacing height is higher than the workpiece surface before air gouging;

[0031] Secondary heat preservation and tempering: After welding is completed, cover the periphery of the welding position of the workpiece with lime again.

[0032] In order to ensure the gouging quality and avoid the situation that the shape and size are out of control, and secondly to prevent local overheating of the workpiece, resulting in other problems of the workpiece, and to facilitate the discovery of problems and immediate adjustment, the thickness of each layer of gouging during the air gouging process is between 2 - 4 mm.

[0033] In order to let the workpiece change temperature slowly, a sharp change in temperature will cause the stress of the workpiece to change. During the primary heat preservation process, the covering thickness of lime is greater than 100 mm.

[0034] In order to ensure the welding quality, avoid defects such as lack of fusion and slag inclusion, control deformation, and facilitate inspection and immediate discovery of problems, during the surfacing operation process, the height of each layer of surfacing is between 3 - 5 mm.

[0035] In order to let the workpiece change temperature slowly, a sharp change in temperature will cause the stress of the workpiece to change. During the secondary heat preservation and tempering process, the covering thickness of lime is greater than 100 mm.

[0036] The judgment basis for reaching the deepest part of the crack during gouging is that the sound of air gouging changes, or obvious metal brightness appears or the detection result of a flaw detector.

[0037] Embodiment

[0038] During the operation of the crusher frame, cracking of the lower frame is more common because it is the basic part of the whole structure and bears the main force. In particular, cracking of the lower frame in the horizontal axis direction is relatively common because the crusher drives the horizontal axis through the motor and then drives the large and small gears by the horizontal axis to achieve crushing. Of course, the upper frame may also crack, but the repair methods mentioned here are applicable to both the upper and lower frames, and have been successfully repaired for the upper and lower frames of two cone crushers in the concentrator and the crushers in the stone factory.

[0039] Introduction to the structure of the lower frame, combined with Figure 1 as shown in the serial numbers 1-5 in : the lower frame base support rib 1, the inner ring 2 for installing the main shaft, the lower frame assembly 3, the horizontal shaft 4, and the cracking position of the base support rib 5.

[0040] As Figure 1 , the cracking position of the crusher lower frame (the cracking position 5 of the base support rib) is close to the left side of the horizontal shaft 4, and the actual on-site photo is as Figure 2 shown. Before repair, the crusher needs to be completely disassembled until only the lower frame assembly 3 and the main shaft remain. After inspection, Figure 1 the cracking length in is 150 mm, the depth is unknown, and the maximum thickness at the cracking position is 100 mm.

[0041] Preheating and air gouging: Use a cutting torch to bake the periphery of the cracking position to preheat the workpiece, reduce the hardness of the steel, improve the efficiency of air gouging, and reduce defects such as cracks and deformation generated during air gouging. When the temperature at the crack on the workpiece surface reaches about 150 °C, start operating with a carbon rod air gouging from the starting point of the crack.

[0042] The air gouging process needs to be carried out layer by layer like peeling an onion, and the thickness of each layer of gouging should not be too large (preferably between 2-4 mm). The operator needs to rely on experience to check the gouging groove after gouging to a certain depth to judge whether the deepest part of the crack has been reached. As Figure 3 shown, after it is determined that the deepest part of the crack has been gouged, a groove with shallow ends and deep middle will be formed.

[0043] Initial heat preservation and cooling: After air gouging is completed, cover the periphery of the air gouging with lime. If the surface of the workpiece is not flat, more lime needs to be piled up for covering. Due to the good heat preservation performance of lime, the workpiece cools naturally to room temperature in the heat preservation environment, and this process takes about one day to reduce the problems mentioned in the above difficulties.

[0044] Surfacing operation: After the workpiece cools naturally, clean the lime on the surface and prepare for surfacing. The surfacing process is opposite to air gouging and needs to be carried out layer by layer. The height of each layer of surfacing should be as thin as possible until the surfacing height is slightly higher than the surface of the workpiece before air gouging, and then stop.

[0045] Secondary heat preservation and tempering: After welding is completed, immediately wrap the workpiece with lime again. The lime layer slows down the heat dissipation, allowing the workpiece to cool slowly to room temperature. This process takes about one day. Through this process, a simple tempering process is achieved, reducing welding stress and further solving the above-mentioned difficult problems. The effect after welding is as shown in Figure 4 shown, and the heat preservation state is as shown in Figure 5 shown. In addition, in order to make the lime better cover the periphery of the repaired crack, plates are also used to simply cover the welding periphery.

[0046] The effects achieved by the technical solution of this application are as follows:

[0047] 1. Greatly shorten the repair time: Compared with the traditional replacement method which takes 75 days, this method only needs 17 days to complete the repair, greatly reducing the equipment downtime, helping the enterprise to quickly resume normal operation, and avoiding the economic losses caused by long-term downtime.

[0048] 2. Improve safety: Effectively solve the safety hazards caused by the accumulation of old spare parts, and at the same time reduce the risks during the waiting period for new racks.

[0049] 3. Significantly reduce costs: Compared with the high cost of purchasing a new rack, this repair method provides a more economical option, saving a large amount of money for the company. It is calculated that after successfully repairing 4 sets of racks in a certain concentrator, the total cost savings is about 2.5 million yuan.

[0050] 4. Strong applicability: This repair method is not only applicable to the lower rack, but also applicable to the upper rack, and is suitable for a variety of crushers, with wide applicability and practicability, further enhancing its value.

Claims

1. A method for repairing a crusher frame, characterized in that: include: Preheating: Bake the area around the crack of the crusher frame, and preheat the workpiece until the temperature of the crack on the surface of the workpiece reaches 150°C. The workpiece is the crusher frame; Air planing: Use a carbon rod to plan the crack in layers from the starting point until the deepest part of the crack is reached. Initial heat preservation: After the gouging is completed, cover the periphery of the workpiece with lime and allow it to cool naturally; Overlay welding operation, layer by layer, until the overlay welding height is higher than the workpiece surface before gouging; Secondary insulation and tempering: After welding, the area around the welding position of the workpiece is covered with lime again.

2. A method for repairing a crusher frame according to claim 1, characterized in that: The thickness of each layer removed during the gouging process is between 2-4 mm.

3. A method for repairing a crusher frame according to claim 1, characterized in that: The lime coverage thickness during the initial insulation process is greater than 100mm.

4. A method for repairing a crusher frame according to claim 1, characterized in that: During the cladding process, the height of each layer of cladding is between 3-5mm.

5. A method for repairing a crusher frame according to claim 1, characterized in that: The lime coverage thickness during the secondary insulation and tempering process is greater than 100mm.

6. A method for repairing a crusher frame according to claim 1, characterized in that: The basis for judging whether the planing has reached the deepest part of the crack is the change in the sound of the air planer, the appearance of obvious metal brightness or the detection results of the flaw detection instrument.

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