1. Overview
The residue conveyor and motor at Guixi Smelter of Jiangxi Copper Corporation are connected via a hydraulic coupling combined with a clutch. On-site clutches are prone to damage, while hydraulic couplings feature high failure rates, low efficiency, and oil leakage that causes environmental pollution; locked rotor conditions may easily lead to explosions. A technical renovation adopting permanent magnet coupling technology is planned for the conveyor. The original hydraulic coupling will be replaced with a Wolfer permanent magnet coupling, and the clutch will be removed to reduce failure points. Meanwhile, it achieves vibration damping and isolation, lowers starting current, provides locked rotor protection, and greatly reduces maintenance workload while improving operational reliability.
Permanent magnet drive technology is a groundbreaking new technology developed globally in recent years. Permanent magnet couplings boast outstanding characteristics including high reliability, torque transmission without rigid connection, adaptability to harsh working environments, substantial reduction of overall system vibration, lowered system maintenance requirements, extended service life of the system, and zero generation of high-order harmonics. These superior properties make them the preferred choice for technical renovation of heavy-duty equipment such as residue conveyors and belt conveyors.
2. On-site survey data
Drag Conveyor Parameters for Anode Butts
| Motor nameplate | parameter | Load | Parameter |
|---|---|---|---|
| Motor Model | YE2-180L-4 | Load Model | |
| Rated Power kW | 22 | Load Type | Transport Aircraft |
| Rated Speed rpm | 1500 | Load Shaft Power kW | —— |
| Rated Current A | Rated flow m³/h | —— | |
| Rated Voltage V | 380 | Head m | —— |
| Power Factor | 0.86 | Load Efficiency | —— |
| Explosion-proof Requirements | —— | Explosion-proof Grade | —— |
| Ambient Temperature | Indoor | On-site noise dB | —— |
3. Renovation Plan Description
According to the on-site conditions, the residual pole conveyor is used for feeding copper ingredients and transporting materials to the feeding point. It starts and stops about hundreds of times every day with uneven time intervals between each operation, and the shortest interval is around 30 seconds. Therefore, the equipment utilization rate is extremely high, and safe and reliable products are required.
After extensive research and investigation, the Wofu permanent magnet coupling WF-CT350022T was finally adopted in September 2017 to replace the original hydraulic coupling and remove the original clutch at the same time. It supports frequent start-stop operations, optimizes the starting mode of the reducer motor, isolates vibration, and improves system reliability. The addition of a bearing base can better extend the service life of the single-point bearing at the load section. Furthermore, it is a mechanical soft starting device that requires no additional installation of any other control equipment, and the conveyor can be controlled simply by starting and stopping the motor.
Maintain the state of the original system. If stalling frequently occurs on the conveyor, install a speed detection probe on the load side to further protect the system.
Due to the low rotating speed and excessive torque of the conveyor, as well as severe on-site vibration, a supported permanent magnet coupling is selected. The permanent magnet coupling is equipped with an additional support base and bearing housing, which can protect the bearings of the load and eliminate the impact caused by axial play of the load. The installation dimension of the permanent magnet coupling is 650mm, while the overall dimension of the on-site hydraulic coupling plus clutch is 1030mm, leaving sufficient space for installation.
4. Comparison Before and After Installation
5. Usage Effect
After adopting the permanent magnet coupling, on-site vibration has been greatly reduced. The hydraulic coupling and clutch have been removed, making the entire equipment system more stable and lowering equipment maintenance workload. At present, the equipment has been operating in good condition and is worthy of promotion.
