Horizontal Sludge Hollow Blade Paddle Dryer Energy Saving

Horizontal Sludge Hollow Blade Paddle Dryer Energy Saving

Product Description:

A paddle dryer is a low-speed agitation dryer that uses an internal stirring paddle to ensure wet materials come into full contact with the heat carrier and heated surfaces, thus achieving the drying purpose. It is typically horizontal, dual-shaft, or quad-shaft type. Paddle dryers are classified into hot air type and conductive type.

Product Introduction

This paddle dryer product can indirectly heat or cool paste, granular, powder, and slurry materials, and can complete unit operations such as drying, cooling, heating, sterilization, reaction, and low-temperature combustion. The special wedge-shaped stirring heat transfer blades in the equipment have high heat transfer efficiency and a self-cleaning function for the heat transfer surface.

Working Principle

Densely arranged wedge-shaped hollow blades run along a hollow shaft, through which the heat transfer medium flows. The heat transfer area per unit effective volume is large, and the heat transfer medium temperature ranges from -40℃ to 320℃. It can be steam or a liquid such as hot water or thermal oil. Indirect conduction heating is used, eliminating the risk of heat loss through air; all heat is used to heat the material. Heat loss is limited to heat dissipation to the environment through the insulation layer of the unit. The wedge-shaped blade heat transfer surface has a self-cleaning function. The relative movement of material particles with the wedge-shaped surface creates a washing effect, removing adhering material and maintaining a clean heat transfer surface during operation. The blade dryer's shell is Ω-shaped, typically housing two to four hollow stirring shafts. The shell has sealed end caps and a top cover to prevent material dust leakage and ensure optimal performance.

The heat transfer medium flows through a rotary joint, through the shell jacket, and the hollow stirring shafts. The hollow stirring shafts have different internal structures depending on the type of heat transfer medium to ensure optimal heat transfer.

Performance Characteristics

◎ Low Energy Consumption: Due to indirect heating, there is no large amount of air carrying away heat. The dryer's outer wall is also insulated. For slurry materials, only 1.2 kg of steam is needed to evaporate 1 kg of water.

◎ Low System Cost: The large heat transfer surface area per unit effective volume shortens processing time and reduces equipment size, significantly reducing building area and space requirements.

◎ Wide Range of Processable Materials: It can handle heat-sensitive materials and materials requiring high-temperature processing using various heat transfer media. Commonly used media include steam, thermal oil, hot water, and cooling water.

It can operate continuously or intermittently, making it applicable in many fields.

◎ Low Environmental Pollution: Since it does not use air, dust entrainment is minimal. Solvent evaporation is very small, facilitating processing. For contaminated materials or situations requiring solvent recovery, a closed-loop circulation system can be used.

◎ Low Operating Costs: Its structure minimizes wear and tear, resulting in very low maintenance costs.

◎ Stable operation: Due to the special compression-expansion stirring effect of the wedge-shaped blades, the material particles are in full contact with the heat transfer surface. Within the axial range, the temperature, humidity, and mixing degree gradient of the material are very small, thus ensuring the stability of the process.

Suitable Materials

The paddle dryer has been successfully used in the food, chemical, petrochemical, dye, and industrial sludge industries. Its heat transfer, cooling, and stirring characteristics enable it to perform the following unit operations: combustion (low temperature), cooling, drying (solvent recovery), heating (melting), reaction, and sterilization. The stirring paddles also act as heat transfer surfaces, increasing the heat transfer area per unit effective volume and shortening processing time. The wedge-shaped paddle heat transfer surface also has a self-cleaning function. The compression-expansion stirring function ensures uniform mixing of materials. The material moves in a "piston flow" along the axial direction, with very small gradients in temperature, humidity, and mixing degree within the axial range. Using heat transfer oil as the heat medium, the paddle dryer can perform low-temperature combustion operations. For example, calcium sulfate dihydrate (Ca2SO4·2H2O) is converted to calcium sulfate hemihydrate (Ca2SO4·1/22H2O) through combustion. Sodium bicarbonate (NaHCO3) is converted to soda ash (Na2HCO3) through calcination. Cooling media such as water or cooling brine can be introduced for cooling. For example, the paddle-type alkali cooler used in the soda ash industry replaces the old-fashioned air-cooled alkali cooler, saving energy and exhaust gas treatment equipment, and reducing operating costs. Drying, the equipment's primary function, eliminates the need for hot air, making solvent recovery, energy consumption, and environmental control ideally manageable. It is particularly suitable for materials requiring solvent recovery, flammable, easily oxidized, and heat-sensitive materials. It is widely used in the fine chemical, petrochemical, and dye industries. The uniformity of temperature, humidity, and mixing within the axial range allows the equipment to be used for heating or melting, or for some solid material reactions. It has been successfully used in the compound fertilizer and modified starch industries. The paddle dryer can be used for sterilizing food and flour. The large heating area within a unit effective volume quickly heats the material to the sterilization temperature, avoiding prolonged heating that could alter the material's quality.

Technical Specifications

Installation structure diagram 

Application Cases

name	Jiangyin Farsun
Processing Equipment:	Paddle Dryer
Initial Moisture:	70%
Final Moisture:	25%
Processing Capacity:	200 kg/h ~ 300 kg/h
Processing Equipment:

Before processing	After processing