Superheated steam drying method for sludge and drying equipment

Abstract

The present invention relates to a sludge drying method, said method utilizes the sensible heat and latent heat of dried tail gas recovered by heat exchanger, and makes it exchange with water and heats it to obtain superheated steam, then makes the superheated steam by fed into a closed direct drying machine to make heat exchange with wet sludge being in said drying machine to obtain the dried sludge. Then said method can make the dried sludge and dried tail gas implement gas-solid separation, so that the dried sludge can be collected. Said drying equipment includes pipe-shell type heat exchanger, heater, closed direct drying machine and gas-solid separator, etc.

Description

technical field [0001] The invention relates to a sludge drying method and equipment, in particular to a sludge drying method and a drying device using superheated steam as a drying medium. Background technique [0002] At present, most of the sludge drying methods are direct drying and indirect drying. The drying medium of direct drying is usually the hot flue gas produced by fuel or waste combustion. The advantage is that the process flow is simple and the processing capacity of a single machine is large. Odor-causing substances must be deodorized before they can be discharged, and the heat loss of the drying tail gas is also very large, resulting in poor economic efficiency of the drying process. Indirect drying, the heat required for drying is transferred to the sludge through heat conduction, instead of using drying medium, the advantage is that there is no danger of explosion and fire, the amount of tail gas produced by drying is small, ...

AI Technical Summary

Problems solved by technology

The drying medium of direct drying is usually the hot flue gas produced by fuel or waste combustion. The advantage is that the process flow is simple and the processing capacity of a single machine is large. Odor-causing substances must be deodorized before they can be discharged, and the heat loss of the exhaust gas is also very large, resulting in poor economic efficiency of the drying process

Indirect drying, the heat required for drying is transferred to the sludge through heat conduction, instead of using drying medium, the advantage is that there is no danger of explosion and fire, the amount of tail gas produced by drying is small, the drying thermal efficiency is high, and the operating cost of tail gas deodorization treatment is relatively low. Low, the economy of drying treatment is better, the shortcoming is that the drying process and equipment are more complicated, the processing capacity of a single machine is small, and it is easy to stick to the wall, so it is not suitable for the sludge with strong adhesion

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