High-temperature returned ash cooling and conveying system for cyclone dust removal

The cyclone dust removal high-temperature return ash cooling and conveying system is an industrial environmental protection device integrating cyclone dust removal, high-temperature return ash cooling and conveying functions. It is mainly used in working conditions requiring the treatment of high-temperature fly ash such as biomass power generation and thermal power generation. It can realize the cooling, collection and transfer of high-temperature ash and slag to ensure the stable operation of subsequent processes.

Core Equipment Composition

The system mainly consists of three parts:

Cyclone Dust Removal Unit: Its core is a cyclone dust collector composed of an air inlet pipe, an exhaust pipe, a cylinder, a cone and an ash hopper. It separates high-temperature return ash from flue gas by centrifugal force, and large-particle dust falls directly into the ash hopper to complete preliminary gas-solid separation.

Cooling Unit: A patented scheme widely used in industry at present adopts a screw cooling structure with cooling jackets. Cooling jackets are arranged outside the cold ash shell, and two hollow screws with opposite rotation directions are installed inside. Cooling water can circulate inside the hollow main shaft and spiral blades of the screws. Heat exchange area is enlarged to realize rapid cooling of return ash within a limited space. Some traditional schemes adopt a two-stage cooler series structure to meet the cooling requirements for higher temperatures.

Conveying Unit: The cooled return ash passes through the buffer bin in sequence and enters the pneumatic conveying bin. Finally, the cooled return ash is sent to the ash silo for storage through the pneumatic conveying pipeline. A sealed scraper conveyor can also be used for sealed conveying to prevent dust leakage.

Working Principle

Flue gas containing high-temperature return ash enters the cylinder of the cyclone dust collector tangentially. Dust is separated by the centrifugal force generated by the rotating air flow. The dust falls along the cone wall into the bottom ash hopper, and the purified gas is discharged from the top exhaust pipe.

High-temperature return ash is discharged from the ash hopper into the cooling unit. The rotating screws push the return ash to move slowly inside the shell. Meanwhile, cooling water in the shell jacket and inside the screws continuously takes away heat through heat exchange to achieve gradual cooling of the return ash.

The cooled return ash is discharged into the conveying unit and sent to the ash silo by pneumatic conveying or mechanical sealed conveying, completing the whole process of dust removal, cooling and conveying.

Main Application Scenarios

This system is mainly suitable for treatment scenarios of high-temperature dust-laden flue gas, and is intensively applied in:

Treatment of return ash from circulating fluidized bed boilers in biomass power plants and coal-fired thermal power plants;

Cooling and conveying of fly ash after flue gas dust removal of high-temperature kilns in the iron and steel metallurgy industry;

Collection and cooling treatment of high-temperature dust in the cement and non-ferrous metal smelting industries.

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