Estudo de otimização da configuração do hidrociclone filtrante

Abstract

The solid-liquid separation can be performed by hydrocyclones, which are interesting equipments because they are simple, compact and present low costs of acquisition, maintenance and operation. Modifications in its conventional structure and/or new geometrical configurations have been proposed in the literature, with the aim to improve the separator performance. The filtering hydrocyclone belongs to this non conventional category, and presents a conical porous wall, where the filtration process occurs. In this work, the separation of concentrate of phosphate rock from water was analyzed in filtering hydrocyclones. By an optimization study, three new geometries of filtering hydrocyclones were found by the combined use of the response surface technique with the Differential Evolution algorithm. These geometries were tested experimentally and compared with the literature. Furthermore, the underflow orifice diameter and the vortex finder length effects were evaluated by the use of Central Composite Design. The three optimum configurations found were: (i) HFOT1 hydrocyclone, with high total efficiency (η = 89,11%); (ii) HFOT2 hydrocyclone, with low underflow-to-throughput ratio (RL = 17,12%) and (iii) HFOT3 hydrocyclone, with low Euler number (Eu = 753). The study of the influence of the variables Du and ℓ showed that: the original values of HFOT1 already seemed to be suitable for the separator give maximum efficiency; the underflow-to-throughput ratio of HFOT2 could still be minimized by the change on its original values of Du and ℓ; the Euler number of HFOT3 was little affected by these variables and, because it remained practically in the same level, it was possible to improve other responses (efficiency and underflow-to-throughput ratio) by changing Du and ℓ, at a low energy consumption.