Paper mill – Dongguan, China
Project Background:
The client is a large paper recycling plant specializing in wastepaper deinking, a critical step in producing recycled paper products. One of the most essential pieces of equipment in their production line is the rotary drum pulper, which is used for breaking down wastepaper and removing ink. The rotary drum pulper operates under harsh conditions, with high-speed rotations and constant exposure to vibration and shock loads. It is also required to handle large quantities of wastepaper, which adds to the stress placed on the mechanical components.
Rotary Drum Pulper Equipment Overview:
- Function: The rotary drum pulper is designed to break down wastepaper and separate ink and other contaminants. It operates continuously under high pressure and temperature conditions, requiring a highly durable and reliable coupling solution to ensure efficient performance.
- Specifications: The rotary drum pulper works at rotational speeds of up to 800 RPM, with torque transmission requirements reaching up to 2000 Nm. The system operates at a temperature range of 45°C to 75°C, with fluctuating load conditions.
Rotary Drum Pulper Technical Parameters:
| Parameter | Details |
|---|---|
| Torque Requirement | Up to 2000 Nm |
| Operating Speed | 600-800 RPM |
| Temperature Range | 45°C – 75°C |
| Load Conditions | Varying load due to high material throughput |
| Coupling Type | Traditional mechanical couplings |
The client faced persistent issues with the mechanical couplings used in the rotary drum pulper, which were prone to wear and tear due to the harsh operating conditions. Frequent breakdowns led to high maintenance costs and downtime, significantly affecting the plant’s efficiency. In search of a more reliable solution, the client turned to Osencmag for a more efficient and durable coupling solution.
Problem Points:
Challenges with the Existing Equipment:
- Excessive Wear and Tear: The traditional mechanical couplings, used to connect the motor and the pulper drum, experienced significant wear and tear. This frequent breakdown resulted in high maintenance costs and significant downtime, which disrupted production.
- Frequent Maintenance: Due to wear and tear from constant use, the couplings required regular maintenance and replacement, increasing operational costs.
- Energy Loss: The mechanical couplings were inefficient at transmitting torque, resulting in power loss and reduced overall system efficiency.
- Poor Shock Absorption: The mechanical couplings could not effectively absorb shock loads and vibrations, which are common in high-speed, high-torque equipment like the rotary drum pulper.
- Contamination Risk: The leaking of lubricants from traditional couplings contaminated the pulping process, which posed environmental and operational risks.
Solution:
To address these challenges, Osencmag proposed the integration of a permanent magnetic coupling solution. This solution is designed to meet the specific requirements of the rotary drum pulper, offering high performance, energy efficiency, and a reduced need for maintenance.
Comparison of Air-Cooled vs. Liquid-Cooled Magnetic Couplings:
Before finalizing the solution, Osencmag considered the advantages of both air-cooled and liquid-cooled magnetic couplings. Here’s a simplified comparison:
| Criteria | Air-Cooled Magnetic Coupling | Liquid-Cooled Magnetic Coupling |
|---|---|---|
| Cooling Method | Air cooling | Water or oil cooling |
| Efficiency | Suitable for standard operating conditions | Ideal for high-power applications or harsh conditions |
| Maintenance | Low maintenance | Requires additional cooling system maintenance |
| Temperature Tolerance | Up to 230°C | Can tolerate up to 350°C |
| Cost | More cost-effective | Higher initial cost, but better for extreme conditions |
For this application, the air-cooled permanent magnetic coupling was selected, as it offers an excellent balance between cost-effectiveness, performance, and low-maintenance needs. The coupling also features a non-contact torque transmission design that ensures energy-efficient operation.
Magnetic Coupling Specifications:
| Specification | Details |
|---|---|
| Magnet Material | NdFeB (Neodymium Iron Boron) |
| Temperature Rating | Up to 230°C |
| Torque Capacity | 2000 Nm (meets requirements of the rotary drum pulper) |
| Housing Material | Cold-rolled steel with corrosion-resistant coating |
| Design | Non-contact, permanent magnetic torque transmission |
| Maintenance | Virtually maintenance-free, no lubrication needed |
Installation Details:
The magnetic coupling was designed to integrate seamlessly into the existing rotary drum pulper system without requiring significant changes to the equipment’s structure. The non-contact design allows for easy installation, as there are no mechanical parts in direct contact, minimizing the wear and tear on the equipment during setup.
Result Summary:
Since the installation of the permanent magnetic coupling, the client has seen several significant improvements in both operational efficiency and cost savings:
- Reduced Downtime: The plant has experienced far fewer breakdowns, as the magnetic coupling’s non-contact design eliminates the common issue of mechanical wear. Maintenance frequency has dropped significantly, allowing for increased production uptime.
- Cost Savings: With lower maintenance needs and reduced energy losses, the client has seen a considerable reduction in overall operational costs. Additionally, the absence of lubrication has eliminated the risk of contamination, leading to savings in material and cleanup costs.
- Improved Efficiency: The permanent magnetic coupling’s non-contact torque transmission has enhanced power transfer, improving overall system efficiency. The reduction in energy losses has translated into better performance and lower energy consumption for the rotary drum pulper.
- Extended Equipment Life: The shock-absorbing capabilities of the magnetic coupling have significantly reduced mechanical stress on other components of the pulper, leading to less wear and a longer lifespan for the entire system.
- Cleaner Process: The absence of lubricants and seals has kept the pulping process cleaner, which has had a positive impact on the quality of the recycled paper produced, while also improving environmental sustainability.
Effect After Transformation:
| Metric | Before Transformation | After Transformation |
|---|---|---|
| Downtime | High (Frequent maintenance) | Reduced (Minimal maintenance) |
| Maintenance Cost | High | Significantly reduced |
| Energy Efficiency | Low | Improved (less energy loss) |
| Vibration | High | Reduced (absorbs shocks) |
| Environmental Impact | Lubricant leakage | No lubrication, cleaner process |
Conclusion
By implementing the permanent magnetic coupling solution, the client has successfully improved the performance and reliability of their rotary drum pulper. The reduction in downtime, lower maintenance costs, and enhanced energy efficiency have led to significant operational improvements and cost savings. The non-contact design of the magnetic coupling has not only eliminated the need for lubrication but also minimized the risk of contamination, improving the overall quality and environmental sustainability of the paper deinking process.
This case demonstrates how Osencmag’s customized magnetic coupling solutions can effectively address the challenges faced by industries operating under harsh conditions, offering long-term reliability and efficiency.
