Standard cleaning procedures ensure impurity removal, moisture control and raw material quality, avoiding agglomeration, equipment wear and low powder purity during ultra-fine grinding.
Step 1: Dry Sorting and Impurity Separation
First remove foreign matters including stones, soil blocks, broken grains, moldy and worm-eaten lentils via vibrating sieve and air classifier. Separate different grain sizes to ensure uniform raw material quality, and clear seed coat fragments and light floating impurities.
Step 2: Primary Water Washing
Put sorted lentils into flowing clean water for rapid rinsing. Wash off surface dust, residual pesticide residues and external dirt, shorten cleaning time to reduce nutrient dissolution loss.
Step 3: Moderate Soaking
Soak cleaned lentils in normal temperature pure water for proper time. Soften the hard epidermal structure, separate residual sticky impurities on the surface, and preliminarily elute partial soluble anti-nutritional substances such as phytic acid. Avoid over-soaking to prevent excessive water absorption.
Step 4: Secondary Fine Rinsing
Take out soaked lentils and rinse again with clean water to wash away mucus, dissolved impurities and floating sundries precipitated during soaking, keep raw materials clean inside and outside.
Step 5: Surface Dewatering
Remove surface free water by draining, vibration dewatering or low-speed centrifugal dehydration. Excess surface water will cause material adhesion, blockage and uneven particle size in ultra-fine grinding.
Step 6: Low-Temperature Pre-Conditioning Drying
Carry out mild low-temperature air drying to adjust lentils to the optimal moisture content suitable for ultra-fine grinding. Stable moisture effectively improves grinding efficiency and finished powder fineness uniformity.
Step 7: Final Inspection
Check for residual impurities, mildew and abnormal grains again, and feed qualified clean lentils into the ultra-fine grinding system.
Key Cleaning Principles
- Keep cleaning process mild to protect internal protein and nutritional components of lentils.
- Strictly control water content to match dry-method ultra-fine grinding requirements.
- Remove fine impurities thoroughly to reduce iron contamination and equipment abrasion during grinding.
