Sewage sludge hollow paddle dryer Sludge drying equipment

Description of Hollow Paddle Dryer:

Hollow Paddle Dryer can indirectly heat or cool the materials in paste, granules, powders and slurries. It can also complete the unit process of drying, cooling, heating, sterilization, reaction and low temperature combustion. the special heat-transfer stirring blade wedge type in the equipment has high heat-transfer efficiency and its heat-transfer surface has self-cleaning function.

A hollow shaft is densely arranged with hollow wedge-shaped blade; heat medium flow to the hollow blades through hollow shaft. the heat transfer area per unit effective volume is large. Temperature of heat medium is from -40 ºC to 320 ºC, may be in the form of water vapor or liquid, such as hot water or heat transfer oil. Indirect conduction heating has no air to carry away the heat, so the heat is all used to heat the material, and the only heat loss is the heat dissipated around from the heat insulation layer. Heat-transfer surface of wedge-shaped blade has self-cleaning function. Relative movements between particles and the wedge-shaped surfaces produce wash effect, which can wash away the adhered material on the surface of the blade, so that a clean heat transfer surface is maintained in the operation. the shell of blade dryer is Ω-type, generally two to four hollow stirring shafts installed in the shell. the shell is equipped with end cover and top to prevent dust escaping.Heat transfer medium flows through the rotary joint, shell jacket and hollow stirring shaft. Depending on the type of heat medium, hollow stirring shafts have different internal structures to ensure optimal heat transfer effect. 

Paddle dryer is widely used in environmental protection, new energy, petrochemical, chemical, metallurgy, foodstuff, pharmaceutical, pesticide industrials and so on for drying powder, granules, filter cake and seriflux materials. It is especially widely used for drying different kinds of sludge.

Features of hollow paddle dryer:

1. Blade paddle dryer is low energy-consumption: due to the indirect heating, there is not a lot of air carrying away the heat; the outer wall of the dryer set the insulation layer. for slurry material, it takes only 1.2kg water vapor to evaporate 1kg water.
2. System of blade dryer is low cost; the heat transfer area is large in unit effective volume, which makes shorter the processing time and the smaller device size, greatly reducing its covering area and building space.
It can handle wide ranges of materials: Using different heat medium, it can not only deal with heat-sensitive materials, but also materials requiring high temperature treatment. Common media are: steam, heat transfer oil, hot water and cooling water.
3. It supports both continuous operation and intermittent operation; it can be applied in many fields.
Environmental friendly: it does not use carry air and carries very little dust material. Material solvent evaporation is little so it is easy to handle. for materials which may cause pollution or requiring solvent recovery, closed circulation can be applied.
4. Low operating costs: little abrasion, low maintenance cost.
Stable operation: due to the special compression - expansion stirring of wedge-shaped blade, material particles have sufficient contact with the heat transfer surface. In the axial zone, materials have low temperature, low humidity and small mixing gradient so as to ensure the stability of the process.

Parameters of hollow paddle dryer: