Volm Two-Stage Liquid Ring Vacuum Pumps Empower Efficient and Stable PVC Production
In PVC suspension polymerization processes, vacuum pumps are critical across six core stages: reactor deoxygenation, post-polymerization degassing, wet material drying, and monomer recovery. Particularly in vacuum drying, maintaining 60~80°C is essential to protect PVC’s heat-sensitive particles from thermal degradation. The client requires 5~15 kPa(A) vacuum (far below single-stage liquid ring pump’s efficient range of 20 kPa(A) to atmospheric pressure). Leveraging deep industry expertise, Volm Pump delivered a customized two-stage liquid ring vacuum pump solution, ensuring stable performance across all PVC production stages.
Three Technical Challenges
1.Efficiency Drop in High Vacuum
• Single-stage pumps exhibit plummeting pumping speeds and surging energy consumption when operating below 20 kPa(A), failing to meet high-flow requirements for drying processes. In contrast, two-stage pumps’ efficiency in high-vacuum operations exceeds single-stage pumps by 35~40%, with proportionally lower energy consumption. Selecting vacuum pumps tailored to specific operating conditions is therefore essential for cost-effective operation.
Remarks: working liquid is 20℃ water, and atmospheric pressure is 101.3kPa.
2.Particle Clogging Risks
• Residual vinyl chloride monomer particles (50~100μm) may clog liquid circuits, triggering unplanned downtime.
3.High-Pressure Sealing Challenges
• Barrier fluid suction pressure for double mechanical seals reaches 0.7 MPa. Manual pressure regulation risks seal failure and leakage.
Volm’s Customized Solutions
1. Two-Stage Pump Design
• Patented 2BE1S Series divides 1:10 compression ratio into two 1:5 stages;
• Inter-stage flow channels optimize gas paths → 40% higher pumping speed at 5 kPa(A), with efficiency increase from 25% to 45%, and 10% energy savings;
• Saves ¥96,000/year in drying alone (800 m³/h at 10 kPa(A)).
2. Anti-Clogging Intelligent System
• Dual self-cleaning filters (50μm precision) + remote electromagnetic flowmeters;
• PLC auto-switches to backup filter & -sends clogging alert, at <80% flow with zero downtime.
3. Self-Regulating High-Pressure Seals
• Self-acting control valves stabilize barrier fluid pressure at 0.3 MPa (which is optimal for seals).
Reliability Validation (2-Year Operation)
| Metric | Performance |
|---|---|
| Vacuum Stability | ≤±1 kPa(A) deviation (>99% uptime) |
| Pumping Speed & Efficiency | ≤±5% pumping speed variation |
| Energy Consumption | ≤5% deviation from theoretical kW·h/m³ |
| Anti-Clogging | 99% particle interception |
| Seal System | 0.3±0.05 MPa pressure stability (>99% uptime) |
| Equipment Reliability | MTBF: ≥8,000 hrs (pump body ≥10,000 hrs) |
| Process Adaptability | Drying temp stability: >99% at 60~80°C |
| Monitoring | 100% real-time data capture |
