Sludge Paddle Dryer

Sludge Paddle Dryer Project Overview

The sludge paddle dryer is a specialized drying machine designed by our factory specifically for sludge generated by municipal wastewater treatment plants, textile dyeing plants, paper mills, electroplating plants, thermal power plants, and chemical plants, providing a solution to your sludge management challenges. Typically, the initial moisture content of sludge is around 80%; after drying, the final moisture content ranges from 10% to 50%, with a moisture content of approximately 30% being most common. The dried sludge takes on a loose, granular form and can be mixed with pulverized coal for direct combustion in boilers. The calorific value of the sludge is approximately 1,500–2,000 kcal, enabling energy savings and reuse. Some types of dried sludge can also be processed into fertilizers and construction materials, or directly landfilled without causing secondary pollution. This transforms waste into a valuable resource, fully meeting environmental protection requirements. The equipment features low energy consumption, and the heat source can utilize steam, thermal oil, flue gas heating (1.1–1.3 kg of steam is required to evaporate 1 kg of water). It offers advantages such as low power consumption, smooth operation, low noise, and minimal labor requirements, with production being largely fully automated.

Working Principle of the Sludge Dryer

Wedge-shaped hollow paddles are densely arranged on a hollow shaft, through which the heat medium flows. The heat transfer area per unit of effective volume is very large. The heat medium temperature ranges from -40°C to 320°C and can be steam or a liquid, such as hot water or thermal oil. Indirect conduction heating ensures that no heat is carried away by air; all heat is used to heat the material. Heat loss is limited to heat dissipation through the insulation layer of the unit to the environment. The heat transfer surface of the wedge-shaped blades has a self-cleaning function. The relative motion between the material particles and the wedge-shaped surfaces creates a scrubbing effect, which removes any material adhering to the surfaces, ensuring a clean heat transfer surface throughout operation. The shell of the paddle dryer is Ω-shaped and typically houses two to four hollow stirring shafts. The shell is equipped with sealed end caps and a top cover to prevent the leakage of material dust and ensure optimal performance.

The heat transfer medium flows through the rotating joint, circulating through the shell jacket and the hollow stirring shafts. The internal structure of the hollow stirring shafts varies depending on the type of heat transfer medium to ensure optimal heat transfer efficiency.