出版社：Grupo de Pesquisa Metodologias em Ensino e Aprendizagem em Ciências
摘要：This paper is intended to explore how changing the frequency of industrial screens processing the dewatering of an iron ore bulk influences the final moisture content. Screen dewatering of particulate systems in size range between 150 μm and 1000 μm, from iron ore, was studied in an industrial environment. The oscillating dewatering screen employed has effective dimensions of 4.2 m long by 1.8 m wide. The screen frequency was controlled by a frequency inverter in the electric circuit of the motor drive. A reduction in the final cake moisture was observed by reducing the frequency. Furthermore, differences between the intrinsic oscillation parameters of the bulk material and that of the oscillatory electromechanical system were detected. To achieve this controlled variation of the frequency levels followed, initially, a continuous level regime (30 minutes per condition), and, later, a sinusoidal and a stepped (squared form at 30 seconds per level) regime. The adoption of the sinusoidal and stepped regime allowed the matching of the same vibrational parameters of the particulate bed with those of the screen, leading to a reduction in the moisture content in the final cake.
