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Description of hollow paddle dryer compared with disc sludge dryer

1. The two kinds of equipment have been used and operated for a long time in developed countries and are relatively mature;
2. The working principle is very similar. The shell is hollow, with jacket, hollow shaft and hollow blade (disc). It is a pressure vessel and is an indirect heating and drying equipment;
3. During the implementation of the project, the external access conditions are basically the same, but the external dimensions of the equipment are slightly different, which can be replaced by each other in the sludge drying project;
4. Adaptability of viscous sludge.
The fan blade can cut the sludge, so the equipment has a certain self-cleaning function for the sludge with little viscosity. However, for the sludge with strong viscosity, because the cross-section of the fan blade is not equal, the mud scraper cannot be used, which will lead to the adhesion of sludge on the drying surface and affect the drying effect and drying capacity of the equipment; The disc of the disc dryer has no cutting force on the sludge, but it is equipped with a mud scraper, which can fully adapt to the high viscous sludge. The maintenance and even replacement of the mud scraper are convenient and the cost is low;
5. Wear resistance and safety. The sediment content of sludge in China is about twice that in developed countries, so the wear resistance should be fully considered in equipment selection. The hollow paddle of the paddle dryer is a pressure vessel with a pressure of 0.3 ~ 1.3MP. It is the structural part of the equipment. Due to the cutting effect on sludge, it will inevitably lead to wear after running for a period of time, and heat transfer oil or steam leakage will occur, which will increase the equipment maintenance cost and reduce the operation time and service life; Similarly, as a pressure vessel, the disc of the disc dryer is also a structural part. There is a pressure of 0.3 ~ 1.3MP inside. The disc has no cutting force on the sludge, so it is not easy to wear. The pushing and mixing of the sludge depends on the pushing agitator at the edge of the disc (small steel plate, fixed at the edge of the disc by bolts, non structural parts), which is convenient to replace and low maintenance cost;
6. The processing capacity of a single equipment mainly depends on the heat exchange area of the equipment. Generally, the paddle dryer can only achieve a heat exchange area of 300m3, so it is difficult for the equipment to be large-scale; The disc dryer can achieve a heat exchange area of 400 ~ 500m3, and the processing capacity of a single equipment is greater;
7. Paddle type generally adopts double shaft or four shaft, with complex structure; Disc dryer is single shaft, simple structure, low failure rate and maintenance cost;
8. The blade dryer has large operation resistance and the disc dryer has small operation resistance. The power consumption per unit heat exchange area of the disc dryer is about 1 / 3 ~ 1 / 4 of that of the blade dryer, with lower power consumption and low operation cost;

9. The prices of the two kinds of equipment in the market are close. After the introduction and localization of disc dryer technology, the price can be greatly reduced.