The sludge belt dryer is arranged with wedge-shaped hollow blades, and the heat medium flows through the blades through the hollow shaft. The heat transfer area within a unit effective volume is large, and the temperature of the heat medium ranges from -40 ℃ to 320 ℃. It can be steam or liquid, such as hot water, thermal oil, etc. Indirect conduction heating does not carry away heat with air, and the heat is used to heat the material. The heat loss is only the heat dissipation to the environment through the insulation layer of the device body. The wedge-shaped blade heat transfer surface has self-cleaning function. The relative motion between the material particles and the wedge-shaped surface produces a scrubbing effect, which can wash away the attached material on the wedge-shaped surface and maintain a clean heat transfer surface during operation.


The shell of the sludge belt dryer is W-shaped, and generally two to four hollow mixing shafts are arranged inside the shell. The shell has sealed end caps and upper caps to prevent material dust leakage and collect material solvent vapor. Set up a stopper at the discharge port to ensure the height of the material level, so that the heat transfer surface is covered by the material and fully functional. The heat medium flows through the shell jacket and hollow stirring shaft through the rotary joint. The hollow stirring shaft has different internal structures according to the type of heat medium to ensure ideal heat transfer effect.


The sludge belt dryer has been successfully used in the fields of chemical, petrochemical, dye, industrial sludge drying, papermaking sludge drying, printing and dyeing sludge drying, and domestic sludge drying. The characteristics of heat transfer, cooling, and stirring of the equipment enable it to perform the following unit operations: calcination (low temperature), cooling, drying (solvent recovery), heating (melting), reaction, and sterilization.


Scope of application of sludge belt dryer:


1. Environmental protection industry: PTA sludge, electroplating wastewater sludge, boiler ash, pharmaceutical factory waste, sugar factory waste, monosodium glutamate factory waste, coal ash.


2. Petrochemical industry: polyolefin powder, polycarbonate resin, high and low density polyethylene, linear low density polyethylene, polyacetal particles, nylon 6, nylon 66, nylon 12, acetate fiber, polyphenylene sulfide, propylene based resin, engineering plastics, polyvinyl chloride, polyvinyl alcohol, styrene, polypropylene, polyester, formaldehyde, styrene acrylonitrile copolymer, ethylene propylene copolymer.


3. Feed industry: soy sauce residue, bone based feed, distiller's grains, food scraps, apple pomace, orange peel, soybean meal, chicken bone feed, fish meal, feed additives, and biological sludge.


Structure and characteristics of sludge belt dryer:


1. Cooling media such as water, cooling salt water, etc. can be used for cooling. For example, the blade type cooling alkali machine used in the soda ash industry replaces the old-fashioned air-cooled cooling alkali machine, saving energy and exhaust gas treatment equipment, reducing operating costs, and can also be used for cooling nickel iron alloy powder and various granular materials. The material can be cooled from 1000 ℃ to less than 40 ℃ in a single machine.


2. Drying, the main function of the equipment, does not use hot air, making solvent recovery, energy consumption, and environmental control in an ideal state that is easy to handle. It is particularly suitable for solvents that need to be recycled, flammable and easily oxidizable heat sensitive materials. It has been widely used in the fine chemical, petrochemical, and dye industries.


3. The stirring blade is also a heat transfer surface, which increases the heat transfer area per unit effective volume and shortens the processing time. The wedge-shaped blade heat transfer surface also has self-cleaning function. The compression expansion mixing function ensures uniform mixing of materials. The material moves in a "piston flow" along the axial direction, and within the axial range, the temperature, humidity, and mixing gradient of the material are very small.


4. The uniformity of temperature, humidity, and mixing degree 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. Paddle dryers can be used to sterilize food and flour. The large heating area within the effective volume of the unit quickly heats the material to the sterilization temperature, avoiding prolonged heating and changing the quality of the material.