1. Introduction
SPMs in flour mills automate essential stages of the milling process—from grain cleaning and tempering to grinding, sifting, and packaging—delivering consistent quality, higher yields, and reduced labor dependency.
2. Key Types of Flour-Mill SPMs
| Machine Category | Primary Operations |
|---|---|
| Grain Cleaning & Conditioning | Aspirators, magnetic separators, destoners, and moisture-controlled tempering bins. |
| Roller Milling SPMs | Servo-controlled multi-stage roller mills for fine grinding and bran separation. |
| Plansifters & Purifiers | Multi-tier sifting with cyclone extractors and purifiers for semolina/flour grading. |
| Bran & By-product Recovery | Bran finishers, pneumatic sifters to separate germ and reduce waste. |
| Packing & Weighing | Multi-head weighers linked to automatic valve or stitch bag fillers (1–50 kg). |
| Automation & Conveyance | Bucket elevators, screw conveyors, diverters, all PLC-integrated. |
3. Process Applications
Wheat Preparation
- Removes stones, dust, ferrous particles.
- Moisture is adjusted for ideal milling pliability.
Grinding & Reduction
- Break and reduction rolls gradually reduce grain to flour.
- Gap-controlled rollers ensure target fineness and extraction rate.
Purification & Classification
- Semolina, flour, and middlings are separated via plansifter decks and air purifiers.
By-product Recovery
- Bran and germ are extracted and directed to feed or oil-processing units.
Packaging
- Automated systems ensure accurate flour bagging and batch traceability.
4. Key Benefits
- Increased Extraction Rate: Up to 1–2% improvement via precision settings.
- Consistent Fineness: ±5 microns—critical for baking, snack, and pasta flour.
- Labor Savings: Reduces manual cleaning, lifting, and sieve servicing.
- Continuous Operations: 24/7 production with CIP-enabled tempering and sifting.
- Traceability: Batch-wise data via PLC/SCADA systems.
5. Design Considerations
- Wheat Characteristics: Moisture, hardness affect tempering and roller config.
- Target Output: TPH goals define number of grinding and sifting stations.
- Final Product Specs: Bread flour, semolina, atta—impact milling curve.
- Cleanability: Dust-tight enclosures, easy-to-clean sieve decks and bins.
- Integration: SCADA/MES ready; support for OPC-UA, Ethernet/IP protocols.
- Maintenance Access: Tool-free roller/sifter replacement and remote diagnostics.
6. Implementation Roadmap
- Initial Assessment: Yield baseline, labor review, and flour consistency audit.
- Pilot Setup: Cleaner + roller + plansifter line to measure gains.
- Full Deployment: Stepwise rollout across all product lines.
- Monitoring Tools: Dashboards for OEE, fineness, and energy use.
- Kaizen Cycle: Monthly refinement of pressure settings and sifting profiles.