Overview of disc dryer:

The disc dryer, as an indirect heating and drying equipment for sludge, has been applied in the chemical industry, food industry, and feed industry for decades. It has now developed into a fairly mature drying process and has a very high market share in the international market. The common feature of sludge incineration is aimed at energy recovery. Sludge has a low calorific value and generally requires the addition of auxiliary fuel, so a process with less auxiliary fuel should be designed, and fluidized bed technology is one of them.

The main body of the disc dryer consists of a cylindrical shell and a set of central penetrations

Composed of disks. The disk group is hollow, and the heat medium flows through here, indirectly transferring heat to the sludge through the disk. The sludge passes between the disc and the shell, receiving heat transferred by the disc and evaporating water. The water vapor formed by the evaporation of sludge water accumulates in the dome above the disc and is carried out of the dryer by a small amount of ventilation. The disc of the disc dryer has two functions: firstly, it provides sufficient heat exchange area for the sludge; secondly, it rotates slowly, and the small propeller on it pushes the sludge to flow in the designated direction and plays a good stirring role. The disc dryer utilizes the double-sided heat transfer of each disc, providing a large heat exchange area in a small space, making the disc dryer compact in size. The rotation frequency of the disc is adjustable, with a speed of about 5r/min, so the wear is minimal. The disc surface is perpendicular to the shaft, so its rotation does not affect the flow of sludge. The disc edge of the disc dryer has some small blades with a certain inclination angle, which not only help the sludge flow in a directional manner, but also play a role in mixing. The shell is stationary, it contains sludge and the water vapor generated by sludge evaporation. There is a fixed scraper on the inner wall of the shell. The scraper is very long and extends to the gap between the discs to prevent large pieces of sludge from solidifying on the discs. Similar to the blades on a disc, a fixed scraper also serves as a stirrer.

disc dryerworking principle:

The disc dryer consists of a cylinder, a disc spindle, a transmission mechanism, and a steam heating system. The cylinder is cylindrical with a jacket, into which steam is introduced, and there is a drainage outlet at the bottom. There is an exhaust port at the top of the cylinder to discharge evaporated water vapor; A feeding port is used to add wet materials into the dryer. There is a discharge port at the bottom of the cylinder for discharging dried materials. There is a cleaning discharge port at each lower end of the cylinder. There is also a blocking plate above the cylinder to keep the turntable self-cleaning. The main shaft inside the cylinder is composed of a hollow main shaft and a hollow disk. Steam is introduced into the main shaft and distributed into the disc. Condensed water and non condensable gas are discharged from the shaft end through the rotary joint.
The outer edge of the disc of the spindle is equipped with an arc plate, which allows the material to slowly move along the dryer cylinder towards the discharge port. The drying of materials is achieved by heating the main shaft and disc with steam, allowing the materials to come into full contact, and then discharging them through an induced draft fan. The main shaft of the dryer is driven to rotate by a motor and a reduction mechanism. The steam heating system consists of rotary joints, metal hoses, steam traps, globe valves, ball valves, sight holes, steam water separators, etc., to ensure that the main shaft disc is always filled with saturated steam and to ensure the smooth discharge of condensed water.
disc dryerMain features:
The disc dryer has a larger heat transfer area than the double axis blade sludge dryer, and the production area can reach 400 square meters. Therefore, the disc dryer is more suitable for large-scale municipal sludge drying treatment.
1. The surface of the heat transfer disk is smooth, not easy to scale, not easy to wear, and has good heat transfer performance;
2. The blades inside the dryer are buried in the material, and the heat transfer area can be fully utilized;
3. The rotating disc is equipped with a scraper, which can clean the material on the surface of the disc;
4. Dry engineering closed operation, suitable for situations where wet gases are harmful and have odors;
5. The equipment runs smoothly, with simple operation and maintenance, and low operating costs;
6. Can operate continuously or intermittently, designed according to customer needs;

7. The heat transfer medium can be steam or high-temperature heat transfer oil.

disc dryerSuitable materials for drying:

This machine is used for drying filter cake shaped and granular materials that are not easily clumped or adhered after drying. Typical dry materials include fish meal, graphite, carbon black, polyethylene powder, feed, distiller's grains, sludge, corn sprouts, etc.