Superheated steam drying method for sludge and drying equipment

Abstract

The sludge drying method is to use a heat exchanger to recover the sensible heat and latent heat of the drying tail steam, exchange heat with water, and then heat it into superheated steam. The mud is exchanged for heat and mass, and the dried sludge and the dried tail steam are separated from the steam-solid to collect the dry sludge, and the separated dry tail steam is sent to the heat exchanger for heat recovery. The dried tail steam is exchanged After heating, it condenses into a saturated soda-water mixture, which is discharged after sewage treatment. The drying device consists of a shell-and-tube heat exchanger, a heater, a closed direct dryer and a vapor-solid separator. The tube side of the shell-and-tube heat exchanger leads to the liquid working medium, and its outlet is connected to the inlet of the heater to heat The outlet of the closed direct dryer is connected to the inlet of the closed direct dryer, the wet sludge inlet is provided in the closed direct dryer, the outlet of the closed direct dryer is connected to the inlet of the steam-solid separator, and the drying tail gas of the steam-solid separator The outlet is connected to the shell side of the shell and tube heat exchanger.

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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