Core Functions of Screening Machines

1. Impurity Removal

   • Eliminates foreign materials (e.g., stones, straw, dust) through sieve filtration, air classification, or gravity separation. Examples:
     • Rapeseed vibrating screens separate husks and dust ;
     • Wheat scab-cleaning screens use density tables and multi-layer sieves to remove moldy particles .

2. Material Grading

   • Classifies raw materials by size, density, or shape. Examples:
     • Three-layer sieves simultaneously separate oversized impurities, qualified particles, and fine powder ;
     • Pharmaceutical vibrating screens customize sieve meshes to filter oversized residues and fine powder .

3. Contamination Prevention Design

   • Features include fully enclosed structures, easy-to-clean materials (e.g., 304 stainless steel), and automatic discharge. Examples:
     • Food-grade screens adopt sealed designs to prevent dust leakage ;
     • Anti-clogging mechanisms in medical-grade screens avoid material adhesion .

Key Cleaning and Inspection Features

1. Multi-layer Sieve Combinations

   • Upper sieves intercept large impurities, while lower sieves filter fine powders for precise grading .
   • Customizable mesh sizes (2–500 mesh) adapt to diverse material properties .

2. Air Classification Assistance

   • Integrated fans or airflow systems remove lightweight impurities (e.g., bean skins, grass seeds). Examples:
     • Food particle screens use airboxes to blow away lightweight residues ;
     • Wheat screens combine density tables and airflow to separate moldy grains .

3. Automatic Impurity Discharge

   • Self-cleaning mechanisms reduce manual intervention. Examples:
     • Rotary screens expel impurities via rotational motion ;
     • Linear vibrating screens channel waste to dedicated outlets .