System for desulfuration and ash removal of flue gas from steel plant sintering by ammonia method

Abstract

The invention relates to a system for desulfuration and ash removal of flue gas from steel plant sintering by an ammonia method, and belongs to the field of mechanical equipment. The system for desulfuration and ash removal of flue gas from steel plant sintering by an ammonia method comprises a hydraulic backflushing stirring pump, an annular stirring device, an ash solution elevator pump, a deposition tank, a sludge pump, a pressure filter, a middle lifting tank and a middle elevator pump. An ash removal unit of the system for desulfuration and ash removal of flue gas from steel plant sintering by an ammonia method changes the conditions that the existing system for desulfuration and ash removal by an ammonia method adopts a bag-type filter or a self-cleaning filter and thus slag removal is difficult; blocking appears easily; maintenance is carried out frequently; operation management is complex; and a filter inner frame is easy to be damaged because of over-high backwashing pressure. The ash removal unit of the system for desulfuration and ash removal of flue gas from steel plant sintering by an ammonia method adopts deposition and press filtration two-step ash treatment so that clear liquid two-step shunting is realized and an ash removal rate reaches above 90%, has a low operation cost, realizes ash cake forming and convenient transport, and guarantees normal production of a desulfuration unit of the system for desulfuration and ash removal of flue gas from steel plant sintering by an ammonia method. Therefore, the system provided by the invention is suitable for desulfuration and ash removal of flue gas from steel plant sintering.

Description

technical field [0001] The invention relates to an ammonia method desulfurization and ash removal system for sintering flue gas in a steel plant, which belongs to the category of mechanical equipment. Background technique [0002] The sintering flue gas of the iron and steel plant emits a large amount of sulfur dioxide, causing serious air pollution. With the requirements of the national environmental protection policy, the sintering flue gas of iron and steel plants has gradually achieved desulfurization and discharge standards. [0003] There are many processes for sintering flue gas desulfurization. At present, there are mainly ammonia method, magnesium method and calcium method at home and abroad. As a new, efficient and economical desulfurization process, ammonia desulfurization has gradually become the leading process for sintering flue gas desulfurization. [0004] Ammonia desulfurization is to use ammonia water to react with sulfur dioxide in flue gas to achieve de...

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Problems solved by technology

The ash in the system has a certain impact on the ammonia desulfurization system, which mainly leads to the deposition of a large amount of ash in the pipelines, reaction towers, concentration cooling towers and equipment in the system, which affects the normal operation of the system, causes wear, corrosion and blockage of pipelines and equipment, and causes ammonia The quality of ammonium sulfate, a by-product of desulfurization by desulfurization method, has declined, which affects the benefit

[0005] At present, the ammonia-based desulfurization and ash removal system mainly adopts bag filters or self-cleaning filters. Due to the small size of ash particles (with a particle size range of 0.5-15 μm) and large quantities, at this stage, bag filters or self-cleaning filters Difficult slag discharge, easy to block, frequent maintenance, complex operation management, high backwash pressure, which causes easy damage to the inner frame of the filter, etc.

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