Precoating em filtro de mangas para remoção de material particulado e potencial redução da emissão de SO2 na dessulfurização

Abstract

The steel industry is responsible for generating pollutants that need to be treated before being released into the atmosphere, various gases such as ammonia, benzene, carbon monoxide, sulfur dioxide and particulate matter. To carry out the cleaning of particulate matter, the dirty gas passes through gas-solid separation equipment, such as bag filters, which have high collection efficiency for a wide granulometric range and easy operation. To increase bag filter collection efficiency, some industries use a bag pre-treatment called precoating, which consists of covering the surface of non-woven filter media with a certain particulate material, forming a fine layer of dust that increases the time mango saturation. In addition to the benefits in filtration, the hydrated lime present in the precoating layer could be investigated in the removal or reduction of sulfur dioxide, in order to reduce the visibility of gases in chimneys. However, studies on precoating and the influence of operating parameters in bag filters in the treatment of sintering gases are rare. Thus, this work aims to evaluate the efficiency of precoating, varying its humidity and thickness, in the filtration of gases and the desulphurization of gases from the steel industry. For this purpose, in Chapter 2, the parameters of thickness and humidity of the precoating layer were evaluated on the efficiency of collecting micro and nanoparticles; in Chapter 3 the same parameters were evaluated in 50 filtration cycles; and, in Chapter 4, the efficiency of hydrated lime in a gas desulphurization unit was evaluated. The results showed that precoating increased the collection efficiency for micro and nanoparticles by up to 3%, increased the cycle time by up to 9000s and that hydrated lime showed 100% absorption of sulfur dioxide in a batch system