A grooved cone dry colloid mill uses a precision-machined conical rotor rotating within a grooved conical stator at 3,000–9,000 RPM — the adjustable cone gap (0.025–2 mm) generating intense shear and attrition across a large processing surface area. Processing 0.5–300 kg/h with D90 output of 10–150 µm, it achieves finer particle reduction than toothed designs and handles heat-sensitive materials at lower rotor speeds — the preferred configuration for fine pharmaceutical and cosmetic powder milling.
Feed material enters from the top of the conical gap; gravity and centrifugal force draw it downward through the narrowing gap between grooved rotor and stator. The adjustable gap (0.025–2 mm) is set by axial rotor position — finer gap gives finer output particle size. Grooving pattern (radial, spiral, or cross-hatched) determines shear-to-impact ratio; spiral grooves maximise shear for waxy or cohesive materials. Lower rotor speed (3,000–9,000 RPM vs. 15,000 for toothed) limits temperature rise for heat-sensitive APIs.
Challenges
Gap Setting Sensitivity
0.025 mm gap tolerance requires precision adjustment; minor misalignment causes rotor-stator contact.
Waxy Material Build-Up in Grooves
Lipid-based or waxy APIs soften under frictional heat and pack into groove channels.
Limited Throughput vs. Toothed Mill
Smaller processing surface area limits maximum throughput compared to toothed rotor–stator.
Groove Wear Changes PSD Over Time
Progressive groove wear widens effective gap; D90 drifts coarser over production campaign.
CIP Access to Narrow Cone Gap
Grooved surface geometry requires validated CIP spray pattern to reach all surfaces.
Solutions
- Micrometer Gap Adjustment Mechanism: Precision screw adjustment with dial gauge: ±0.005 mm reproducible gap setting.
- Liquid Nitrogen Feed Pre-Cooling: Cryogenic pre-cooling of waxy or heat-sensitive feed prevents groove packing and sticking.
- Hard Chrome or DLC-Coated Cone Surfaces: Diamond-like carbon coating extends groove life to >5,000 production hours.
- Inline PSD Sensor with Automatic Gap Feedback: Laser diffraction sensor on outlet triggers gap adjustment to maintain D90 ±5%.
- Quick-Release Cone Extraction Tool: Factory-supplied extraction collar removes rotor cone in <10 minutes for full CIP access.
Applications
- Pharmaceutical: Fine API milling for inhalation (D90 <20 µm), oral solid dosage size reduction, heat-sensitive compound milling.
- Cosmetics: Ultra-fine pigment milling, sunscreen particle size reduction, luxury powder formulation.
- Food & Beverage: Cocoa powder, dried herb, and spice ultra-fine milling for premium product applications.
- Nutraceuticals: Plant extract ultra-fine milling, bioavailability enhancement particle size reduction.
- Chemical: Catalyst ultra-fine powder production, specialty pigment sub-50 µm size reduction.
Models & Capacities
| Type 2 — Grooved Cone Dry Colloid Mill: Models & Capacities (1 kg/h to 8,000 kg/h) | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Model | Scale | Throughput [kg/h] | Feed Size Max [mm] | Product Size D97 [um] | Cone Dia Top [mm] | Rotor Speed [RPM] | Tip Speed [m/s] | Cone Angle [deg] | Gap [mm] | Motor [kW] | Overall L [mm] | Overall H [mm] | Weight [kg] | |
| CMD-GC-LAB-80 | Lab | 1-8 | 1 | 30-300 | Dia80 | 6,000-18,000 | 25-75 | 15-30 | 0.05-1 | 0.55 | 500 | 450 | 22 | |
| CMD-GC-LAB-140 | Lab | 5-40 | 3 | 20-250 | Dia140 | 4,500-14,000 | 33-103 | 15-30 | 0.05-1 | 1.1 | 680 | 580 | 58 | |
| CMD-GC-PIL-200 | Pilot | 15-100 | 5 | 15-200 | Dia200 | 3,600-10,800 | 38-113 | 20-40 | 0.05-2 | 2.2 | 860 | 720 | 120 | |
| CMD-GC-PIL-280 | Pilot | 40-250 | 8 | 10-150 | Dia280 | 3,000-9,000 | 44-132 | 20-40 | 0.05-2 | 4.0 | 1,050 | 880 | 225 | |
| CMD-GC-P-350 | Production | 80-500 | 10 | 8-120 | Dia350 | 2,800-8,400 | 51-154 | 25-45 | 0.05-3 | 7.5 | 1,250 | 1,050 | 420 | |
| CMD-GC-P-450 | Production | 150-1,000 | 12 | 6-100 | Dia450 | 2,500-7,500 | 59-177 | 25-45 | 0.05-3 | 11 | 1,500 | 1,250 | 680 | |
| CMD-GC-P-550 | Production | 300-2,000 | 15 | 5-80 | Dia550 | 2,200-6,600 | 63-190 | 25-45 | 0.05-3 | 18.5 | 1,750 | 1,450 | 1,050 | |
| CMD-GC-P-650 | Production | 500-3,000 | 18 | 4-60 | Dia650 | 2,000-6,000 | 68-204 | 30-50 | 0.05-4 | 30 | 2,050 | 1,700 | 1,650 | |
| CMD-GC-LP-750 | Large Prod | 800-5,000 | 20 | 3-50 | Dia750 | 1,800-5,400 | 71-212 | 30-50 | 0.05-4 | 45 | 2,400 | 1,950 | 2,500 | |
| CMD-GC-LP-900 | Large Prod | 1,500-8,000 | 25 | 2-40 | Dia900 | 1,500-4,500 | 71-212 | 30-50 | 0.05-5 | 75 | 2,800 | 2,300 | 4,000 | |