Efeito da vibração mecânica perpendicular na formação e remoção de tortas de filtração de aerossóis

Abstract

The current and growing demand for products causes an intensification of activities applicable to the industrial sector. Consequently, increases the amount of tailings produced. This, in turn, must be discarded in a manner as not to pollute the environment. More specifically in industries working with particulate matter is observed, among other concerns, not to discard the solid material in the air, aiming to minimize the impacts to the environment. In order to render operation of gas-solid filtration more efficient, studies in bag house filters, manufactured of synthetic material are performed using a wide range of particulate materials and filter media. In addition to increased filtration efficiency, these studies aim to further simplify this process, making it cheaper. The objective of this study is to evaluate the influence of vibration frequency on formation of filtration cake. For this, we used synthetic filter media made of polyester and polypropylene, to separate particles of phosphate rock and manioc starch of gas stream with flow velocity of 10 cm/s. Tests to evaluate the behavior of the system subjected to vibration loads of particles of different particle sizes were performed, in addition to analyzing the response of processes with particles of different shapes. The continuous vibration during the filtration process had occurred due to an eccentric propelling motor which caused an oscillatory movement in the vertical direction in the filter. Various frequencies of vibration were evaluated. The treatment of the experimental data been accomplished through the use of correlations are well established in the literature (Ergun, 1952 and Endo, 1998). The influence of different vibration frequencies is evaluated through the study of the structural parameters of the filtration cake. It was also performed the calculation of Euler number for understanding of energy demand of the proposed system. It found that the frequency of mechanical vibration, concomitantly with filtration process, affects the formation structure of the filtration cake. In the proposed system, the vibration contributed to the formation of thinner and less porous filtration cake, for all tested dusty materials, which increased the energy demand of the process. However, the adhesion force per unit area was lower in filtration systems with smaller particles, in processes submitted to mechanical vibration.