Based on the dry fractionation technical workflow from protein-mill.com, a full industrial pulse (pea, faba bean, lentil, mung bean) protein production line is fully water-free, chemical-free, and divided into five core equipment modules: raw material pre-treatment system, ultra-fine grinding system, high-precision air classification separation core system, powder collection & closed-loop recycling system, and auxiliary supporting & post-processing equipment. All machines adopt food-grade stainless steel, negative-pressure dust sealing, and standard explosion-proof design for fine organic powder processing.
1. Raw Material Pre-Treatment Equipment (Pretreatment Section)
This module removes impurities, outer hull fiber and excess moisture to eliminate separation interference; poor pre-treatment will directly reduce final protein purity.
- Raw Material Storage & Quantitative Feeding Bin + Screw Conveyor Feeder
Sealed storage silos store bulk pulses; variable-frequency screw feeders deliver stable, uniform raw material flow to downstream equipment, avoiding uneven feeding that disrupts grinding precision. - Multi-Layer Vibrating Cleaning Sieve
Separates large foreign impurities: stones, stalks, broken pods, clods and oversized bean fragments. - Magnetic Metal Separator
Installed between conveying pipelines to capture iron scraps, preventing grinding mill liner abrasion and metal contamination of food-grade protein powder. - Air Aspiration Gravity Destoner
Removes light dust, weed seeds and heavy stones via combined airflow and gravity sorting. - Precision Pulse Dehulling Machine
Core pre-treatment unit: mechanical friction peels off fibrous seed coats (hulls). Hull fiber is low-density and will mix with fine protein powder during classification if retained, lowering protein concentration. Separated hull fiber is collected separately as dietary fiber by-product. - Low-Temperature Conditioning Dryer (Optional)
Adjusts bean moisture to a stable 8–12% (optimal for dry fractionation). Too high moisture causes powder agglomeration; too low moisture leads to excessive starch fragmentation.
2. Ultra-Fine Grinding Equipment (Cell Liberation Stage)
Grinding breaks legume cell walls to fully detach tiny protein bodies (1–3 μm) from large starch granules (15–40 μm), the prerequisite for effective air classification. Two mainstream industrial mill types for pulse protein lines:
Option A: ACM Integrated Classifier Mill (Compact Combined Unit)
Two-in-one machine integrating grinding and primary coarse separation in one chamber:
- High-speed impact rotor crushes dehulled cotyledons to target D90:10–65 μm;
- Built-in miniature classification wheel screens out oversized unbroken cell agglomerates, automatically recycling them back to the grinding zone;
- Small footprint, low energy consumption, ideal for medium-capacity 500–2000 kg/h production lines.
Option B: ZPS Pin Mill / Wide Chamber Impact Mill (Independent Standalone Mill)
For large-scale high-yield lines (2–10 ton/h) and high-purity protein requirements:
- Contraplex CW II pin mill delivers gentle shear impact to avoid over-grinding starch into micro-fragments;
- Independent grinding chamber achieves complete cell dissociation, with stable narrow particle size distribution for consistent subsequent air classification;
- Matched with separate high-power centrifugal blower for closed material conveying.
Supporting grinding auxiliary:
- Closed-loop air conveying pipelines (food-grade stainless steel, anti-static lining for explosion prevention);
- Frequency conversion control cabinet to adjust rotor speed and precisely lock grinding fineness.
3. Core Separation Equipment: High-Precision Turboplex Air Classifier
The heart of protein-starch separation, standalone ATP multi-wheel ultrafine air classifier after fine grinding mill:
- High-Speed Rotating Classification Wheel Assembly
Adjustable 0–6000 RPM turbine wheel creates controllable centrifugal force to set the separation cut-point between protein and starch. Higher wheel speed intercepts small starch fragments to lift protein purity to 55–65%. - Sealed Classification Chamber
Negative-pressure design prevents fine protein dust leakage; separate dual discharge outlets for two product streams:- Bottom coarse outlet: starch-rich flour (70–85% starch content)
- Top fine airflow outlet: protein-rich concentrate carried by process air
- Variable-Frequency Process Air Blower
Regulates airflow volume to adjust protein yield balance between purity and throughput.
4. Powder Capture & Closed-Loop Recycling System
Captures separated powder fractions and recycles unseparated intermediate mixed powder to boost total protein recovery rate:
- High-Efficiency Cyclone Separators (Primary Collection)
Two sets of cyclones matched to the air classifier’s two outlets:- Fine cyclone: collects light protein concentrate powder suspended in airflow;
- Coarse cyclone: collects heavy starch flour from classifier bottom discharge.
- Pulse Bag Dust Collector (Secondary Dust Filtration)
Captures ultra-fine residual protein dust escaping cyclones, eliminates material loss and workshop dust pollution; filtered clean air circulates back into the classifier to form a fully closed air loop (zero exhaust emissions). - Recycling Screw Conveyor & Intermediate Storage Hopper
Mixed powder containing unseparated protein-starch agglomerates is automatically transported back to the ultra-fine grinding mill for reprocessing, cutting raw material waste by 8–15%. - Vibrant Discharge Unloaders & Powder Buffering Silos
Stabilize powder output flow to avoid blockages and ensure continuous automatic packaging.
5. Post-Processing & Finishing Equipment
Processes collected protein and starch fractions into market-ready finished products:
- Low-Temperature Powder Cooling Conveyor
Reduces powder temperature after grinding/classification to prevent protein thermal denaturation and caking; maintains native functional properties (solubility, emulsification). - Multi-Axis Powder Blender (Optional)
Homogenizes protein concentrate batches to stabilize consistent protein content across production runs; can blend with minor food additives for custom functional protein powders. - Automatic Quantitative Packaging Machine
Dual independent packaging stations for two products:- High-protein concentrate (food-grade 25kg kraft bags / 1kg retail pouches);
- Starch-rich legume flour bulk packaging for feed and food thickener applications.
- Metal Detector & Check Weigher
Final quality inspection before finished product storage, eliminating metal contamination and under/over-weight bags.
6. General Auxiliary & Safety Control System (Mandatory for Full Lines)
- Central PLC Intelligent Control Cabinet
Unified touchscreen monitoring for all equipment parameters: feeding speed, mill rotor RPM, classifier wheel frequency, airflow, temperature and real-time protein yield data; auto-alarm for blockage, overheating or abnormal pressure. - Explosion-Proof Safety Accessories
Anti-static pipeline lining, explosion vent panels, inert nitrogen protection system (optional for high-volume fine powder lines), spark extinguishers to mitigate organic dust explosion risks. - Air Compressor & Pneumatic Valve Set
Supplies compressed air for bag filter pulse cleaning, classifier air damper adjustment and automatic valve switching. - Centralized Dust Removal System & Noise Reduction Enclosures
Meets food factory environmental standards for dust emission and decibel limits.
Line Capacity Matching Reference
- Lab/R&D small line (50–200 kg/h): Dehuller + ACM integrated classifier mill + single-wheel mini air classifier + small cyclone + manual packaging
- Medium industrial line (500–2000 kg/h): Full pre-treatment set + ACM mill + ATP single-wheel air classifier + dual cyclones + automatic packaging
- Large commercial line (2–10 ton/h): Complete pre-treatment system + independent pin mill + multi-wheel high-capacity air classifier + full closed recycling loop + twin-station automatic packaging line
