A standard horizontal plough shear wet granulator is a cylindrical batch reactor with a central shaft carrying 4–12 offset plough blades (60–250 RPM, tip speed 2–8 m/s) that lift and project the powder charge in three-dimensional parabolic arcs. Binder liquid is sprayed simultaneously through top-mounted nozzles onto the moving bed — homogenising, wetting, and granulating in 3–8 minutes per batch. Processing 10–500 kg batches, it achieves granule density of 0.4–0.9 g/cm³ and D90 of 0.3–2.5 mm as a high-speed RMG alternative.
Challenges
Granule Over-Growth from Rapid Binder Addition
Fast binder addition rate causes runaway agglomeration — dense oversized granules unsuitable for compression.
Dust Cloud During Dry Powder Charging Phase
High-speed blades in dry mode generate concentrated dust before binder addition — HPAPI exposure risk.
Non-Uniform Binder Distribution from Point-Source Nozzles
Single or poorly positioned nozzles create wet and dry zones — broad PSD and bimodal distribution.
Temperature Rise from Blade Friction During Extended Processing
Sustained blade rotation raises product temperature above binder gel point — alters granule morphology.
Blade Wear from Dense Mineral Excipients (CaCO₃, DCPA)
Calcium salts and mineral fillers abrade plough blade face — changes blade clearance and mixing pattern.
Solutions
- PLC-Controlled Binder Addition Rate (Peristaltic Pump, ±3% of Setpoint): Programmed binder rate prevents rapid agglomeration — consistent granule size per batch.
- Contained Charging via Split Butterfly Valve + Dust Extraction Nozzle: Closed charging interface with local exhaust ventilation maintains OEB 3–4 during dry phase.
- Multi-Nozzle Spray Bar Spanning Full Vessel Length: Spray bar distributes binder uniformly across the moving powder bed — narrow PSD achieved.
- Jacketed Vessel Wall with Cooling Water (15–25°C): Wall jacket limits product bed temperature rise to <35°C throughout the granulation cycle.
- Hardened Blade Face (Stellite 6 or Tungsten Carbide Hard-Facing): TC hard-face extends blade service life 5–8× against dense mineral excipients.
Applications
- Pharmaceutical: High-shear wet granulation for tablet compression — aqueous and solvent binder systems under GMP.
- Nutraceuticals: Supplement tablet wet granulation for capsule and sachet manufacture.
- Food & Beverage: Instant beverage granule wet agglomeration for improved dissolution and flow.
- Chemical: Detergent granule wet agglomeration, agrochemical active granule formation.
- Cosmetics: Pressed compact granule wet granulation for foundation and compact powder bases.
Product Catalogue & Technical Datasheet
Model | Scale | Bowl Vol. (L) | Batch Size (kg) | Blade Motor (kW) | Blade RPM | Tip Speed (m/s) | Granule D90 (mm) | Discharge Time (s) | L × W × H (mm) | Weight (kg) |
PSW-010 | Lab | 10 | 2–6 | 1.5–3 | 60–250 VFD | 2–6 | 0.3–2.5 | <45 | 900×550×1,100 | 280 |
PSW-030 | Pilot | 30 | 8–18 | 4–7.5 | 60–250 VFD | 2–7 | 0.3–2.5 | <50 | 1,200×700×1,400 | 520 |
PSW-100 | Pilot/Prod | 100 | 30–60 | 11–18.5 | 60–250 VFD | 3–7 | 0.3–2.5 | <55 | 1,700×950×1,750 | 1,050 |
PSW-300 | Production | 300 | 90–180 | 30–37 | 60–200 VFD | 3–8 | 0.3–2.5 | <55 | 2,500×1,250×2,100 | 2,200 |
PSW-600 | Production | 600 | 180–360 | 55–75 | 60–200 VFD | 3–8 | 0.3–2.5 | <60 | 3,200×1,600×2,500 | 4,200 |
PSW-1000 | Large Prod | 1,000 | 300–600 | 90–132 | 60–180 VFD | 3–8 | 0.3–2.5 | <60 | 4,000×1,900×2,900 | 7,500 |
PSW-3000 | Large Prod | 3,000 | 900–1,800 | 220–280 | 60–150 VFD | 3–8 | 0.3–2.5 | <60 | 7,000×2,800×3,500 | 18,000 |