Volm VMB05 Double-Casing Multistage Centrifugal Pump in 200 kt/a Alkane-Aromatic Unit
In petrochemical processing, 200 kt/a alkane-aromatic units are pivotal for heavy oil upgrading and high-value chemical production. The hydrogenation feed pump, as the "heart" of the unit, must deliver explosive mixtures of high-pressure hydrogen and feedstock (e.g., wax oil, residue) to reactors at 8.5 MPa. Original canned motor pumps failed during commissioning, exposing critical flaws. Volm's VMB05 double-casing multistage centrifugal pump resolved these limitations through engineered innovation.
Three Failures of Canned Motor Pumps
1.Excessive Maintenance
• Shield sleeve wear caused motor winding failures → 4 repairs/year, 72 hours/downtime per incident.
2.Low Efficiency
• 15% flow diverted for motor cooling → actual efficiency only 65%.
3.Poor Load Adaptability
• Instability during ±20% flow fluctuations.
VMB05 Engineering Breakthroughs
1. Double-Casing Structure for High Pressure
• Forged steel casing with center support withstands 10 MPa design pressure (well above 8.5MPa operating pressure);
• FEA-optimized thickness → API 610 3× nozzle loads, ≤0.03mm thermal displacement (vs. 0.1mm in canned motor pumps);
• Extends seal life to 25,000 hours.
2. Cartridge Quick-Replacement Design
• 32-component core bundle (impellers, guide vanes, shaft, etc.) can be replaced in ≤8 hours without pipe disassembly (vs. 24 hours for canned motor pumps).
3. Hydraulic Precision & Sealed System
• CFD-optimized narrow-vane impellers and guide vanes + precision casting (±0.05mm tolerance) → 70% efficiency (+5% vs. canned motor pumps).
• API 682 cartridge seals:
1. Plan 11 self-flushing (≤5% flow) prevents coking;
2. Plan 53B barrier fluid (+0.14MPa over seal chamber) with accumulator and DCS monitoring → zero leakage.
4. Operational Flexibility
• Impellers in series + balance drum reduce axial load by 60%;
• Stable operation at ±30% flow fluctuation (50~80 m³/h verified).
Operational Results (Since March 2024)
| Metric | Performance |
|---|---|
| MTBF | ≥12,000 hours |
| Maintenance Cost | -40% |
| Single Repair Time | -22.5 hours |
| Efficiency | 70% (+5% vs. baseline) |
