Application scheme of steel roller production line in mine
1. Selection of idler type of mining belt conveyor
In the mining environment, the belt conveyor needs to withstand high load, strong impact, coal dust, gravel and other harsh conditions, so the selection of idlers needs to take into account the three core indicators of wear resistance, bearing capacity and tightness. According to the differences in application scenarios, the following types are mainly used:
Groove idler group
As the core component of the main bearing section, it adopts a three-section design (35° groove angle) to disperse the pressure of the conveyor belt by increasing the contact area. The surface of its steel roller body has been quenched with high frequency, and the hardness reaches HRC58-62, which is 2.3 times higher than that of ordinary idlers, especially suitable for the transportation of large materials such as raw coal and ore.
Buffer idlers
It is installed under the blanking point and adopts a rubber ring + steel skeleton composite structure. The Shore hardness of the rubber ring is controlled at 65±5, which can absorb the impact energy of the material, reduce the peak force of the conveyor belt by 40%, and effectively prevent the belt from tearing. An iron ore application case shows that the buffer idler extends the life of the belt by 18 months.
Set of aligning idlers
It adopts the design of tapered roller body + automatic correction mechanism, when the belt running amount exceeds 1/20 of the length of the roller, the tapered roller generates lateral force distribution and automatic correction. Its bearing housing adopts a labyrinth seal, with an IP protection rating of IP54, and can still maintain a correction accuracy of less than 0.5mm in dusty environments.
Transition idler group
It is used in areas where the conveyor belt is changed from flat to trough or reverse, and adopts a 5-section gradient groove angle design (10°→35°). The optimized roller structure through finite element analysis improves the uniformity of stress distribution by 35% and avoids roller fracture caused by stress concentration.
2. Optimization scheme of steel idler production line
In order to meet the special needs of the mining scene, the production line needs to be transformed in a targeted manner:
Material reinforcement process
The roller body is made of 16Mn alloy steel, and the tensile strength after normalization + tempering treatment reaches ≥590MPa. The wall thickness tolerance of the steel pipe is controlled within ±0.3mm, and the coaxiality is ≤ 0.5mm through real-time monitoring by the laser diameter gauge.
Bearing system upgrade
Double-row tapered roller bearings are adopted, and the axial bearing capacity is increased by 2.1 times compared with deep groove ball bearings. The mating surface of the bearing housing and the roller body is ground and the surface roughness Ra≤0.8μm, which effectively prevents the loosening of the fit caused by vibration.
Innovative sealing structure
Develop a triple sealing system: the first is a nitrile rubber sealing ring (temperature resistance -30°C~120°C), the second is a polyurethane dust cover, and the third is a labyrinth air gap seal. After 500 hours of dust test, the internal cleanliness retention rate ≥ 95%.
Intelligent detection system
The integrated machine vision inspection station identifies the surface defects of the idler in real time through a 2 million pixel industrial camera, and the defect detection rate ≥ 99.2%. The rotating test bench can simulate the actual working conditions and detect the radial runout (≤0.8mm) and axial passage (≤1.2mm) of the idler.
3. Application effect evaluation
In the renovation project of a 10-million-ton coal mine, after the optimized steel idler production line was adopted:
The average service life of idlers has been extended from 12 to 24 months
Belt deviation failure rate reduced by 67%
The annual maintenance cost is reduced by about 3.8 million yuan
Line changeover time has been reduced from 4 hours to 1.5 hours
