50/60HZ Steam Heating Hollow Paddle Dryer System , Industrial Paddle Dryer For Sludge

Q1: How does a paddle dryer achieve drying?  
A: The paddle dryer uses steam, hot water, or thermal oil as the heat medium. The medium flows into both the jacket surrounding the shell and the hollow shaft of the paddles, turning the inner wall of the shell and the surface of the paddles into heat transfer surfaces. Wet material is continuously exposed to fresh heating surfaces through stirring, flipping, compressing, and relaxing actions by the wedge-shaped paddles. Moisture gradually evaporates while the material moves axially toward the discharge end, ultimately discharging uniform dry product.

Q2: Why does the paddle dryer have high thermal efficiency?  
A: It primarily employs indirect conductive heating, eliminating the need for large volumes of hot air to carry away moisture. Heat loss mainly occurs through insulation heat dissipation from the equipment, resulting in high thermal utilization—typically reaching 85%–90%. The unit has a large heat transfer area per effective volume, especially due to the hollow paddles participating in heat exchange, enabling high evaporation capacity even with a compact footprint.

Q3: What types of materials are suitable for paddle dryers?  
A: They are ideal for processing pastes, filter cakes, slurries, granules, and highly viscous or easily agglomerated materials such as municipal sludge, industrial sludge, chemical filter cakes, pharmaceutical residues, and food protein waste. The wedge-shaped paddles feature self-cleaning action, reducing material adhesion and improving heat transfer uniformity, which benefits sludge reduction and subsequent incineration or landfill disposal.

Q4: What should be considered when using a paddle dryer?  
A: During operation, feed rate, main shaft speed, and heat medium temperature must be carefully controlled to avoid excessive current, overloading of shaft power, or insufficient residence time. Seals at the shaft ends, bearing lubrication, and condensate drainage should be regularly inspected to prevent leaks, overheating, or water hammer. When handling corrosive materials like sludge, appropriate materials should be selected based on chloride content, pH value, and other factors, along with dust collection, exhaust gas treatment, and condensate recovery systems.