Sludge granulation and drying device and method

Abstract

The invention relates to sludge granulation and drying device and method, which can safely and effectively treat wet sludge of a sewage treatment plant so as to facilitate the subsequent resource development and utilization of sludge. The device comprises a screw extrusion granule forming machine, a spout fluidized bed and a dried sludge granule stock bin, and the screw extrusion granule forming machine comprises a drive shaft, a screw feeder, a sludge extrusion forming pore plate and a rotating cutter. The method comprises the following steps of: dividing the spout fluidized bed into an upper spout bed area and a lower fluidized bed area, which are communicated, by using a middle partition board; loading the wet sludge granules from the screw extrusion granule forming machine downward into the spout bed from the bed surface of the spout bed; leading the primarily dried sludge granules to flow to the bottom of the fluidized bed from the bottom opening of the spout bed, and leading the other part of hot gas medium to enter the fluidized bed from a fluidized air inlet to deeply dry the sludge granules; enabling the dried sludge granules to move upward from the bottom of the fluidized bed to the bed surface of the fluidized bed; and finally, overflowing the dried sludge granules out from the fluidized bed to enter the dried sludge granule stock bin.

Description

technical field [0001] The invention relates to a device and method for treating wet sludge, in particular to a sludge granulation and drying device and method. Background technique [0002] With the acceleration of urbanization and the improvement of people's living standards, the amount of urban domestic sewage has increased dramatically. Sludge, as an auxiliary product after sewage treatment in sewage treatment plants, is rich in harmful substances such as organic decay, bacterial cells and heavy metals, which has a great impact on the environment. Sludge treatment has become a major problem that plagues sewage treatment plants and the whole society. How to safely and effectively treat urban domestic sludge has become a hot research topic today. [0003] The water content of raw sludge in sewage treatment plants is as high as 95%. The current mechanical dehydration method can only reduce its water content to 80%. Subsequent treatment and disposal are very difficult. It ...

AI Technical Summary

Problems solved by technology

[0004] In a conventional fluidized bed dryer, the wet sludge after mechanical dehydration is easily bonded into agglomerates in the fluidized bed, causing the fluidized bed dryer to fail to work normally. The phenomenon of mud bonding and agglomeration is more serious; on the other hand, the conventional fluidized bed dryer is not conducive to the sewage due to the uneven particle bed structure and the accumulation of air bubbles, which cause abnormal fluidization phenomena such as channeling and surging in the bed. mud granulation drying

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