Challenges
Lower Maximum Pressure vs. External Gear Pump (<25 bar)
Internal gear geometry limits achievable differential pressure — not suitable for high-pressure injection or high-resistance pipelines.
Crescent Divider Wear Reducing Volumetric Efficiency
The fixed crescent bears on both gear sets — abrasive fluid or dry running rapidly wears crescent face and reduces flow.
Limited Speed Range (Lower Max RPM than External Gear)
Internal gear configuration limits maximum speed to 500–1,200 RPM — throughput per unit size is lower than external gear.
Priming Limitation on Very Low Viscosity Fluid (<5 cP) at High Suction Lift
Slip at low viscosity plus high suction lift combined can prevent reliable self-priming.
Crescent and Gear Material Compatibility with Aggressive Solvents
Crescent divider material must be compatible with solvent — swelling or chemical attack changes gap geometry.
Solutions
- Maximum Operating Pressure Boosted by External Gear Pump in Series: Series arrangement uses internal gear pump for suction and external gear for high-pressure discharge — best of both types.
- PTFE or PEEK Crescent Divider (Chemical-Resistant, Low-Friction): PTFE or PEEK crescent provides chemical resistance and self-lubricating surface — extends service life on all fluids.
- Variable Speed Drive (VFD, 20–100% of Rated Speed) for Flow Turndown: VFD provides flow rate turndown without mechanical throttling — maintains efficiency across operating range.
- Flooded Suction Arrangement + Foot Valve at Low Viscosity: Flooded suction eliminates lift — foot valve prevents siphon back-drainage between cycles.
- Metal Crescent for Chemical Service (Hastelloy C-276 or Duplex SS): Metallic crescent selected by compatibility — no swelling or dimensional change in aggressive solvents.
Applications
- Food & Beverage: Yogurt, cream, fruit pulp, tomato paste, beer, wine — gentle shear-sensitive fluid transfer.
- Pharmaceutical: Oral suspension, cream, gel, ointment — gentle transfer without particle degradation.
- Cosmetics: Shampoo, conditioner, lotion, liquid soap — viscous product filling and circulation.
- Biotechnology: Fermentation broth, cell culture media, biological active — ultra-gentle low-shear transfer.
- Chemical: Paint, varnish, adhesive, polymer dispersion — high-viscosity gentle positive displacement.
Models & Capacities
Type 1B — Internal Gear Pump (Crescent Pump): Models & Capacities | ||||||||||||
Model | Scale | Flow Rate [L/min] | Flow Rate [m³/h] | Ring Gear Ø [mm] | Speed [RPM] | Max Pressure [bar] | Shear Rate (approx.) [s⁻¹] | Max Viscosity [cP] | Max Temp [°C] | Motor [kW] | Inlet/Outlet Ø [mm] |
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IGP-025 | Lab | 0.5–5 | 0.03–0.3 | Ø25 | 50–600 VFD | 10 | <500 | 1,000,000 | 120 | 0.12 | DN 10 |
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IGP-040 | Pilot | 2–15 | 0.12–0.9 | Ø40 | 50–800 VFD | 16 | <500 | 1,000,000 | 150 | 0.18 | DN 15 |
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IGP-063 | Pilot | 5–40 | 0.3–2.4 | Ø63 | 50–900 VFD | 16 | <500 | 1,000,000 | 150 | 0.37 | DN 20 |
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IGP-100 | Production | 15–120 | 0.9–7.2 | Ø100 | 50–1,000 VFD | 20 | <1,000 | 1,000,000 | 150 | 0.75 | DN 25 |
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IGP-125 | Production | 25–200 | 1.5–12 | Ø125 | 50–1,000 VFD | 20 | <1,000 | 1,000,000 | 150 | 1.5 | DN 32 |
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IGP-160 | Production | 50–350 | 3–21 | Ø160 | 50–900 VFD | 25 | <1,000 | 1,000,000 | 150 | 2.2 | DN 40 |
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IGP-200 | Production | 80–600 | 4.8–36 | Ø200 | 50–800 VFD | 25 | <1,000 | 1,000,000 | 150 | 3.0 | DN 50 |
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IGP-250 | Production | 150–1,200 | 9–72 | Ø250 | 50–700 VFD | 25 | <1,000 | 1,000,000 | 150 | 5.5 | DN 65 |
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IGP-315 | Large Prod | 300–2,000 | 18–120 | Ø315 | 50–600 VFD | 25 | <1,000 | 1,000,000 | 150 | 7.5 | DN 80 |
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IGP-400 | Large Prod | 500–3,500 | 30–210 | Ø400 | 30–500 VFD | 25 | <1,000 | 1,000,000 | 150 | 11 | DN 100 |
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IGP-500 | Large Prod | 800–6,000 | 48–360 | Ø500 | 20–400 VFD | 25 | <1,000 | 1,000,000 | 150 | 15 | DN 125 |
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