What It Is
How It Works
What It Is
An octagonal blender is a tumble-type batch reactor with an eight-sided polygonal shell rotating on trunnion-mounted horizontal axis. The eight planar faces alternately lift, cascade, and redirect the powder charge; generating cross-flow mixing superior to cylindrical drums. Designed for 50–5,000 L, it processes free-flowing to mildly cohesive powders (Carr Index <25%) without internal agitator components, preserving fragile granule and coated particle integrity.
How It Works
As the octagonal shell rotates, each face lifts the charge until avalanche angle is exceeded; cascading it in complex cross-flow. Each face transition redirects trajectory, generating helical and radial mixing components. Fill levels of 40–70% ensure adequate headspace for cascade motion. Loading door doubles as discharge port, enabling gravity-assisted complete batch recovery without residual heel in 10–30 minutes.
Challenges
Binary Mixture Segregation
Density and size differentials cause de-mixing during deceleration toward discharge.
Cohesive Powder Limitation
Carr Index >25% resists the free-cascade mechanism; agglomerates persist.
Scale-Dependent Cascade Dynamics
RTD and blend time change non-linearly with vessel size on direct scale-up.
Electrostatic Accumulation
Low-conductivity powders adhere to octagonal faces, degrading blend uniformity.
Fill Level Sensitivity
Operation outside 40–70% sharply degrades cascade efficiency and blend quality.
Solutions
- VFD Speed and Ramp Profiles: Programmed acceleration/deceleration prevents segregation at discharge orientation.
- Internal Intensifier Bar: Disrupts cascade trajectory for cohesive powders without complex internal geometry.
- Froude Number Scale-Up: Constant Fr (= N²R/g) across sizes ensures equivalent cascade dynamics.
- Conductive Surface + Full Earthing: Continuously dissipates electrostatic charge through trunnion bearing assembly.
- Load Cell Fill Monitoring: Enforces validated 40–70% fill window with hard PLC interlock before process start.
Applications
- Pharmaceutical: Final blend, lubricant incorporation (Mgs), HPAPI blend uniformity validation batches.
- Nutraceuticals: Vitamin/mineral premix, protein powder, botanical extract powder integration.
- Food Processing: Spice/seasoning blending, coffee/tea premix, powdered ingredient homogenization.
- Chemical: Catalyst blending, pigment premixing, fine chemical powder homogenization.
Models & Capacities
| Octagonal Blender — Models & Capacities (10 L Laboratory to 20,000 L Large Production) | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Model | Scale | Net Vol.[L] | Gross Vol.[L] | Batch Size[kg] | Shell Ø[mm] | Shell Width[mm] | Speed[RPM] | Motor[kW] | MixingTime [min] | CV[%] | Overall L[mm] | Overall H[mm] | |
| OB-010 | Lab | 5 | 10 | 1.5–4 | Ø320 | 260 | 6–18 VFD | 0.18 | 5–15 | <5 | 600 | 1,100 | |
| OB-025 | Lab | 12 | 25 | 4–10 | Ø440 | 340 | 6–18 VFD | 0.25 | 5–15 | <5 | 820 | 1,300 | |
| OB-050 | Lab | 25 | 50 | 8–20 | Ø560 | 420 | 6–16 VFD | 0.37 | 5–15 | <5 | 1,050 | 1,550 | |
| OB-100 | Pilot | 50 | 100 | 15–40 | Ø700 | 530 | 6–16 VFD | 0.55 | 8–20 | <5 | 1,300 | 1,850 | |
| OB-200 | Pilot | 100 | 200 | 30–80 | Ø880 | 660 | 6–15 VFD | 0.75 | 8–20 | <5 | 1,650 | 2,200 | |
| OB-300 | Pilot | 150 | 300 | 45–120 | Ø1,020 | 760 | 6–15 VFD | 1.1 | 8–20 | <5 | 1,900 | 2,500 | |
| OB-500 | Production | 250 | 500 | 75–200 | Ø1,220 | 920 | 5–14 VFD | 2.2 | 8–20 | <5 | 2,300 | 2,950 | |
| OB-750 | Production | 375 | 750 | 115–300 | Ø1,380 | 1,040 | 5–14 VFD | 3.0 | 10–20 | <5 | 2,650 | 3,350 | |
| OB-1000 | Production | 500 | 1,000 | 150–400 | Ø1,520 | 1,140 | 5–14 VFD | 4.0 | 10–20 | <5 | 2,950 | 3,700 | |
| OB-1500 | Production | 750 | 1,500 | 225–600 | Ø1,760 | 1,320 | 5–12 VFD | 5.5 | 10–25 | <5 | 3,450 | 4,250 | |
| OB-2000 | Production | 1,000 | 2,000 | 300–800 | Ø1,960 | 1,470 | 5–12 VFD | 7.5 | 10–25 | <5 | 3,850 | 4,700 | |
| OB-3000 | Production | 1,500 | 3,000 | 450–1,200 | Ø2,280 | 1,710 | 5–12 VFD | 11 | 12–25 | <5 | 4,500 | 5,500 | |
| OB-5000 | Large Prod | 2,500 | 5,000 | 750–2,000 | Ø2,720 | 2,040 | 4–10 VFD | 15 | 12–30 | <5 | 5,400 | 6,600 | |
| OB-7500 | Large Prod | 3,750 | 7,500 | 1,125–3,000 | Ø3,140 | 2,360 | 4–10 VFD | 22 | 15–30 | <5 | 6,300 | 7,600 | |
| OB-10000 | Large Prod | 5,000 | 10,000 | 1,500–4,000 | Ø3,480 | 2,610 | 4–10 VFD | 30 | 15–35 | <5 | 7,000 | 8,500 | |
| OB-15000 | Large Prod | 7,500 | 15,000 | 2,250–6,000 | Ø4,060 | 3,050 | 4–8 VFD | 45 | 15–35 | <5 | 8,200 | 9,800 | |
| OB-20000 | Large Prod | 10,000 | 20,000 | 3,000–8,000 | Ø4,560 | 3,420 | 4–8 VFD | 55 | 20–40 | <5 | 9,200 | 11,000 | |