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

Abstract

The invention relates to a circulating fluidized bed wet sludge drying and incineration treatment method with a particle dryer, which is used in a circulating fluidized bed incinerator or a circulating fluidized bed boiler with a moisture content of 60-90%. Wet sludge, the drying and incineration of wet sludge is concentrated in a single device. After the wet sludge is dried in the particle dryer, it is returned to the furnace for incineration together with the circulating ash, so that the large amount of water contained in the wet sludge will not be carried out with it. The high-temperature flue gas from the furnace enters the tail flue together, but is drawn out with the fluidized gas of the particle dryer to reduce the heat loss of the system; after the exhaust gas of the particle dryer is dedusted and dehumidified, it is recycled as the fluidized gas of the particle dryer or sent into the furnace Incineration, no smelly gas will be emitted during the treatment process.

Description

technical field [0001] The invention relates to a treatment method of waste (wet sludge), in particular to a treatment method of wet sludge combining drying and incineration with particle drier. 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 a large amount of organic matter, refractory organic matter, various trace elements, pathogenic microorganisms, parasite eggs, and heavy metals. [0003] The sludge treatment method centered on incineration can achieve the goals of reduction, stabilization and harmlessness. However, most of the exis...

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 incineration of dry sludge will produce a large amount of NOx, and 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

[0004] Directly add undried wet sludge to the incinerator for incineration, and unit processes such as sludge drying, incineration, and even flue gas harmless treatment can be concentrated in a single device at the same time, simplifying the sludge incineration treatment process , to reduce the cost of treatment; but the moisture contained in the wet sludge will be discharged out of the furnace together with the flue gas produced by incineration, taking away a lot of heat and increasing the consumption of auxiliary fuel

Images