Horizontal disc dryer: mainly composed of a jacket, a single axis rotor, and a transmission device. The sludge is indirectly heated and dried by heat transfer through the jacket, hollow shaft, and hollow disc welded on the shaft. The disc does not cut the sludge, but instead stirs the sludge through the action of the pushing mixer at the edge of the disc, constantly updating the drying surface, thus successfully achieving the purpose of drying.
Hollow blade dryer: mainly composed of a jacket, double axis (or four axis) cylindrical blades, and a transmission device. The sludge is indirectly heated and dried through heat transfer through the jacket, hollow shaft, and hollow blades welded on the shaft. The lotus shaped blades cut and stir the sludge, constantly updating the drying surface, thus successfully achieving the purpose of drying.
So, what is the difference between a horizontal disc dryer and a hollow blade dryer?
1. Both devices have been in operation for a long time and are relatively mature;
2. The working principle is very similar. The shell is hollow with a jacket, a hollow shaft, and hollow blades (discs), which belong to pressure vessels and are all indirect heating and drying equipment;
3. The requirements for external access conditions during the implementation of the project are basically the same, except for slight differences in the external dimensions of the equipment, which can be replaced by each other in the sludge drying project;
4. Compliance of viscous sludge. The blade shaped blades of the blade dryer have a cutting effect on sludge, and this equipment has a certain self-cleaning function for sludge with low viscosity. However, for sludge with strong viscosity, due to the uneven cross-section of the blade, it is not possible to use a scraper, as this will cause the sludge to adhere to the drying surface, affecting the drying effect and equipment drying; The disc of the disc dryer has no cutting force on the sludge, but it is equipped with a scraper blade, which can meet the requirements of high viscosity sludge. The inspection, repair, and even replacement of the scraper blade are very convenient and cost-effective;
5. Wear resistance and safety. In the issue of sludge drying, full consideration is given to wear resistance. The hollow cylindrical blade of the blade dryer is a pressure vessel with a pressure of 0.3-1.3MP inside, and is a structural component of the equipment. Due to the cutting effect on sludge, it will inevitably cause wear and tear after a period of operation, resulting in leakage of heat transfer oil or steam (if heat transfer oil is used as a heating object as deemed appropriate, it may cause safety accidents!), thus increasing equipment maintenance costs, reducing operating time, and preserving the lifespan of the equipment; As a pressure vessel, the disc of the disc dryer is also a structural component, with a pressure of 0.3-1.3MP inside. The disc has no cutting force on the sludge, and due to its low wear, the pushing and stirring of the sludge rely on the action of the pushing mixer (small steel plate, fixed to the edge of the disc by screws, non structural component) at the edge of the disc. It is easy to replace and has low maintenance costs;
6. It is strongly advocated that the disposal of a single device should be determined by the size of the surface or object with simple heat exchange. Like blade dryers, blade dryers can only achieve a size of 300M3 for simple heat exchange surfaces or object surfaces, making it difficult to scale up the equipment; The disc dryer can achieve a size of 400-500M3 for simple heat exchange of surfaces or object surfaces, with more experience in handling a single device;
7. The blade type is considered suitable and uses double or four axes, with a complex structure; The disc dryer is a single shaft, with a simple structure and low failure rate and maintenance costs;
8. The blade dryer has high operating resistance, while the disc dryer has low operating resistance. The power consumption per unit of surface or object with simple heat exchange is about 1/3 to 1/4 of that of the blade dryer, resulting in lower power consumption and lower operating costs;
9. The prices of the two types of equipment in the market are close, and after the introduction and localization of disc dryer technology, the price can be significantly reduced.
Due to this, it can be concluded that the horizontal disc dryer has certain advantages in comprehensive considerations such as investment cost, operational safety and reliability, continuous operation time, and operating expenses.
