1. Introduction
SPMs in rice mills automate core processing tasks such as cleaning, dehusking, polishing, grading, and packaging. These machines increase throughput, reduce grain breakage, and help maintain consistent quality from paddy intake to dispatch.
2. Key Categories of Rice-Mill SPMs
| Machine Category | Typical Operations |
|---|---|
| Paddy Cleaning | Aspirators, destoners, magnetic separators for removing husk, stones, and metals. |
| Dehusking/Shelling | Rubber roll huskers and centrifugal shellers for bran removal with minimal breakage. |
| Paddy-Brown Separation | Gravity or indented separators to split brown rice from unhulled grains. |
| Whitening & Polishing | Multi-stage friction or abrasive polishers for bran removal and glossy finish. |
| Grading & Sorting | Length graders, optical color sorters to reject broken or discolored rice. |
| Destoning & Air Cleaning | Stone extractors and aspirators to remove heavy particles and chaff. |
| Weighing & Packing | Automated weighers with valve baggers or sewing systems for retail/export sacks. |
| Automation Integration | PLC-driven elevators, conveyors, and diverters for flow continuity and control. |
3. Typical Rice-Milling Line Applications
Pre-Processing
- High-efficiency scalper sieves and pre-cleaners to prep paddy for husking.
Dehusking
- Adjustable rollers reduce cracking; auto-clear blockages using reversible rolls.
Milling & Polishing
- Polishing pressure control enables head-rice retention while meeting grade specs.
Sorting
- Color sorters ensure export-grade visual quality; length graders reduce sub-spec grains.
Packing
- Multi-head weighers connected to sealing/stitching systems for bag sizes from 5 kg to 50 kg.
4. Benefits
- Higher Head-Rice Yield: Optimized shellers and gentle polishers minimize broken grains.
- Uniform Quality: Integrated sorters remove defects and improve consistency.
- Labor Efficiency: Reduces manual handling and fatigue in hot/dusty mill environments.
- High Throughput: Up to 12 TPH per line with 24/7 uptime.
- Compliance & Safety: Food-grade construction, sealed conveyors, traceable batches.
5. Design & Selection Considerations
- Paddy Characteristics: Moisture, size, and density affect husker and separator settings.
- Throughput Goals: Define TPH needs to size and sequence equipment properly.
- Yield Optimization: Balancing grain pressure and speed minimizes breakage vs. output.
- System Integration: Match control logic and conveyors to layout and existing infrastructure.
- Maintenance: Modular husker rolls, sieves, and polishing chambers ease servicing.
- Utilities: Plan for compressed air, dust extraction, and electrical supply.
6. Deployment Roadmap
- Feasibility Study: Benchmark yield loss, energy use, labor hours.
- Pilot Run: Test one cell (e.g., cleaner–husker–polisher) to evaluate head-rice gains.
- Rollout Plan: Expand automation to full plant in stages.
- Monitoring Setup: Real-time dashboards for TPH, reject %, yield %, and uptime.
- Kaizen Loop: Monthly tuning of polish pressure, sorter sensitivity, and part replacement schedules.