Dehulling & Separation
Process Objective
Remove the fibrous outer hull from flaxseed kernels to produce two value-added fractions: hull (fiber + lignan concentrate) and kernel (oil + protein concentrate).
Equipment Configuration
Clean Seed → Conditioning → Dehuller → Hull/Kernel Mixture → Air Classifier → Gravity Separator → Hull Stream / Kernel Stream
Dehulling Technologies
| Method |
Principle |
Efficiency |
Capacity |
Oil Loss |
| Centrifugal impact |
Rotor 3000–4500 rpm |
85–90% |
3 MT/hr |
< 2% |
| Roller gap |
Counter-rotating rolls |
80–85% |
4 MT/hr |
< 1% |
Separation Equipment
| Unit |
Type |
Model |
Capacity |
Separation Basis |
| Air classifier |
Zigzag |
ZAC-800 |
2 MT/hr |
Terminal velocity (hull 1–2 m/s, kernel 4–6 m/s) |
| Gravity separator |
Deck type |
GDS-1000 |
1.5 MT/hr |
Density (hull 0.4, kernel 0.6 g/mL) |
| Fraction |
Purity |
Yield |
Application |
| Hull stream |
≥ 92% hull |
30–35% of whole seed |
Fiber enrichment, lignan extraction |
| Kernel stream |
≥ 95% kernel |
60–65% of whole seed |
Oil pressing, protein production |
Process Parameters
| Parameter |
Set Point |
Tolerance |
| Seed moisture (conditioning) |
8–9% |
± 0.5% |
| Dehuller rotor speed |
3500 rpm |
± 100 rpm |
| Air classifier velocity |
4.0 m/s |
± 0.3 m/s |
| Gravity deck angle |
6.5° |
± 0.5° |
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