Flue gas treatment device and rotary hearth furnace high-temperature and high-dust glue gas treatment system

Abstract

The invention discloses a flue gas treatment device and a rotary hearth furnace high-temperature and high-dust glue gas treatment system with the flue gas treatment device. The treatment device comprises a sedimentation furnace, a high-temperature waste heat boiler, a low-temperature waste heat boiler and a steam drum. At least part of heated walls of the sedimentation furnace are water-cooling walls. The steam drum is provided with a water inlet, a water outlet, a gas inlet and a gas outlet. The water outlet communicates with heat exchange medium inlets of all the water-cooling walls. The gas inlet communicates with heat exchange medium outlets of all the water-cooling walls. The water inlet communicates with a heat exchange medium outlet of the low-temperature waste heat boiler, and the gas outlet communicates with a heat exchange medium inlet of the high-temperature waste heat boiler. According to the flue gas treatment device, due to the fact that the heated faces in the sedimentation furnace are reduced, the waste heat utilization rate and effect of flue gas can be effectively improved, meanwhile, the phenomenon of blockage of a superheater, a body flue of a coal economizer and subsequent flues is reduced, and the corrosion situation caused by the flue gas to equipment is effectively improved.

Description

technical field [0001] The invention relates to a flue gas treatment device and a rotary hearth furnace high-temperature and high-dust flue gas treatment system equipped with the flue gas treatment device. Background technique [0002] Rotary hearth furnace is a direct reduction ironmaking process, which has been widely used in some developed countries abroad; in recent years, it has also been gradually promoted and applied in some domestic iron and steel enterprises. A large amount of high-temperature flue gas and zinc-containing dust are produced in the production process of direct reduction iron in rotary hearth furnace, which has the prospect of waste heat utilization and zinc resource recovery. However, due to the high-temperature and high-dust characteristics of the flue gas from the rotary hearth furnace, the flue gas temperature is as high as 1000°C to 1200°C, and the zinc-containing dust in the flue gas has a high viscosity at high temperatures. The following quest...

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Problems solved by technology

[0003] 1. Blockage, blockage is prone to occur in high temperature flue and low temperature flue, etc.

Because the composition and characteristics of the soot and ash of the rotary hearth furnace are complex and changeable, the temperature range of the ash melting point is large, and it is cohesive at high temperature, which is prone to blockage and affects the stability and running time of the system.

[0004] 2. Corrosion, heat exchangers such as water wall, superheater and economizer are prone to corrosion

When the rotary hearth furnace body process is used for direct reduction ironmaking, it is necessary to add a binder. Generally, the binder contains chlorine, resulting in a variety of chlorine salts in the flue gas of the rotary hearth furnace with high temperature and high dust. In the presence of water vapor "Salt mist" will be formed, which will corrode the surface of metal materials, reduce the service life of heat exchangers such as water-cooled walls, superheaters, and economizers, and affect the stability of system operation.

[0005] 3. The thermal efficiency is low. The flue gas of the rotary hearth furnace is generally recovered and utilized by conventional power plant boilers, and the heat recovery efficiency is relatively low.

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