Four-lobed rotors with precision external timing gears generate four equal displacement pulses per revolution producing near-sinusoidal flow with <±3% pressure variation at rated speed. The very small inter-lobe cavity volume minimises shear energy per displaced unit volume. Close-clearance rotor profiles and ultra-smooth bore (Ra <0.4 µm) maximise volumetric efficiency while maintaining full hygienic cleanability. VFD control from 5–300 RPM matches transfer rate precisely to downstream filling or reactor demand.
Challenges
Lowest Flow Rate per RPM of All Lobe Types
Four-lobe small cavity volume requires high RPM for production flow rates.
Highest Fabrication Cost
Four-lobe timing geometry and precision clearance commands premium vs. bi- or tri-lobe.
Sensitivity to Entrained Gas
Four-lobe tight clearances compress gas cavities causing cavitation and noise.
Limited Solids Handling
Very small inter-lobe clearance intolerant of any particulate contamination.
Speed-Dependent Volumetric Efficiency
At speeds >300 RPM, slip across lobe clearances reduces metering accuracy.
Solutions
- Degassing/Deaeration Stage Before Pump Inlet: Removes entrained gas before entry to multi-lobe cavities.
- Precision Ground Rotor (IT6 Tolerance): Minimises clearance variation; maximises volumetric efficiency across speed range.
- 50–1,000 µm Duplex Strainer on Inlet Pipework: Intercepts particulates before multi-lobe clearance zone.
- VFD Fine Speed Control (5–300 RPM, ±0.1 RPM): Enables precision metering and filling-line speed synchronisation.
- Double Mechanical Seal with Quench Circuit: Zero product leakage for biologics and sterile pharmaceutical transfer.
Applications
- Biotechnology: Live cell culture transfer, fermentation broth gentle pumping, biologic API solution.
- Pharmaceutical: Sterile solution metering, protein formulation transfer, zero-shear biologics handling.
- Food & Beverage: Delicate emulsion, cream with fruit pieces, mousse, and texture-critical transfer.
- Cosmetics: Serum, eye cream, and premium lotion transfer where shear alters emulsion structure.
- Dairy: Live probiotic culture transfer, fresh cheese curd, and texture-sensitive dairy product lines.
Product Catalogue & Technical Datasheet
Model | Flow Rate (m³/h) | Speed (RPM) | Diff. Pressure (bar) | Viscosity Max (cP) | Inlet/Outlet Ø (DN) | Pulses/Rev | Metering Accuracy | L × W × H (mm) | Weight (kg) |
ML-001 | 0.05–1 | 5–300 VFD | Up to 8 | 100,000 | DN 15 | 4 | ±0.5% | 320×170×250 | 18 |
ML-004 | 0.2–4 | 5–300 VFD | Up to 8 | 100,000 | DN 25 | 4 | ±0.5% | 380×200×280 | 26 |
ML-012 | 1–12 | 5–300 VFD | Up to 8 | 100,000 | DN 40 | 4 | ±1.0% | 460×240×320 | 40 |
ML-030 | 3–30 | 5–250 VFD | Up to 8 | 80,000 | DN 65 | 4 | ±1.0% | 560×290×380 | 62 |
ML-060 | 8–60 | 5–200 VFD | Up to 6 | 60,000 | DN 80 | 4 | ±1.5% | 680×350×460 | 98 |
ML-080 | 15–80 | 5–200 VFD | Up to 6 | 50,000 | DN 100 | 4 | ±1.5% | 800×410×540 | 145 |