Working Principle
The paddle dryer is a horizontal agitated dryer mainly relying on conductive heat transfer. Its main structure consists of a jacketed W‑shaped shell fitted with paired hollow low‑speed rotating hollow shafts. Multiple stirring blades are welded onto the shafts. Heat carrier is fed into both the jacket and hollow stirring blades, and the two types of heating surfaces heat the materials simultaneously. The heat carrier is usually fed from the middle section of the dryer, passes across the surface of the agitated material bed, and is discharged from the other side.



Dense wedge‑shaped hollow paddles are mounted on the hollow shafts, and the heat medium flows through the hollow shafts into the paddles.

It provides a large heat transfer area per unit volume. The heat medium temperature ranges from -40 to 320°C, which can be steam or liquid media such as hot water and thermal oil. Heating is performed by indirect conduction; no heat is carried away by carrier air, and nearly all heat is used to heat materials. Heat loss is limited to heat dissipation to the environment through the equipment insulation layer. The heat transfer surfaces of wedge paddles feature a self‑cleaning function. Relative movement between material particles and wedge surfaces creates a scouring effect to strip adhered materials, maintaining clean heat transfer surfaces during operation.

Technical Parameters

Product Features
● Compact structure: The primary heat transfer components of the dryer are shovel‑shaped paddles. These paddles are densely and alternately arranged at specified intervals on rotating shafts, achieving high heat transfer per unit volume. For this reason, the equipment has a compact structure and small footprint.

● High heat transfer efficiency: Raw materials are continuously mixed and agitated. The relatively rotating shovel‑shaped paddles, inclined paddle surfaces as well as heating and cooling of the shell ensure uniform heat transfer across all product‑contact surfaces.

● Self‑cleaning performance: Relative rotation of paddles delivers continuous self‑cleaning for adjacent internal surfaces. Caked and accumulated product on paddles can be scraped off and re‑introduced into the process.

● Simple control: The drying process and residence time can be easily monitored, controlled and adjusted. Parameters including the number of shafts or paddles, rotation speed, heat medium temperature and drying duration can be independently set according to physical properties of materials to be dried.

● Low dust and odor emission: Low gas flow rate during drying minimizes dust and odor generation. Accordingly, matched dust collectors or deodorizers can be small‑sized or even unnecessary.

● Suitable for drying high‑moisture products: Equipped with paddle drying elements and continuous mixing and agitation, it can dry high‑viscosity and high‑moisture materials. Its structural design reduces material accumulation in dead corners and avoids overheating, deterioration or spoilage caused by material buildup.

● Almost no abrasion and material loss: Paddles run at low speed of only 10~40 rpm, which reduces erosion and rapid wear of equipment.

Product Applications
● Inorganic chemical industry: Calcium nitrate, calcium sulfate, paper‑making calcium, calcium carbonate, magnesium hydroxide, carbon black, iron black, iron oxide red, soda ash, etc.

● Organic chemical industry: Dyestuffs, industrial plastics, polystyrene, polypropylene, high/low density polyethylene, etc.

● Metallurgy industry: Nickel concentrate powder, sulfur concentrate powder, tar dephenolization, etc.

● Food and pharmaceutical industries: Starch, salt, protein, etc.

● Others: Sludge, waste residue, chicken feed, distiller's grains, etc.