Wet sludge drying and incinerating treatment method employing circulating fluidized bed with combined dryer

Abstract

The invention relates to a cycle fluidizing bed wet mud drying burning method, with composite drier, wherein the invention burns wet mud with water content between 60-90% in the cycle fluidizing bed burning furnace or cycle fluidizing bed boiler, to concentrate the drying and burning in single device; the wet mud is dried in composite drier to be feedback to the hearth to be burnt with cycle ash together, to avoid taking water into tail smoke channel with the high-temperature smoke of hearth, to be leaded out with the fluidizing gas of composite drier, to reduce the heat loss; and the composite drier is arranged with heating coil tube, connected to the tubular heat exchanger of tail smoke channel, to lead in the smoke heat, to be used as the energy to dry wet mud with high-temperature cycle ash; and the discharge gas of composite drier is dedusted and dehumidified to be used as fluidizing gas or fed into hearth to be burnt, without generating smelly gas.

Description

technical field [0001] The invention relates to a treatment method for waste (wet sludge), in particular to a treatment method for wet sludge which combines drying and incineration with a composite dryer. technical background [0002] Sludge is the solid residue after sewage treatment, and the amount of sludge accounts for about 3‰ to 5‰ of the sewage treatment volume (calculated with a water content of 97%). The amount of industrial and domestic sewage treatment in our country is increasing rapidly. With the continuous construction of sewage treatment plants, more sludge will be produced. The composition of sludge is very complex. In addition to a large amount of water, it also contains common organic matter, refractory organic matter, various trace elements, pathogenic microorganisms, parasite eggs, and heavy metals. [0003] The sludge treatment method with incineration as the core process can meet the requirements of reduction, stabilization and harmlessness to the grea...

AI Technical Summary

Problems solved by technology

However, most of the existing sludge incineration methods require the use of special equipment to dry the sludge before incineration. The drying and incineration are completed in two sets of equipment, and the system is complicated; the drying equipment consumes a lot of energy , high operating costs and high safety requirements; and the incineration of dry sludge is easy to produce NOx, so a denitrification device needs to be installed after the incinerator; at the same time, because the sludge contains sulfur, a desulfurization device needs to be equipped after the incinerator

This makes the sludge incineration system complicated and the cost of harmless treatment high

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