In this work, the effect of the configuration on the collection efficiency and pressure drop in small diameter cyclones is evaluated based on neural networks (Functional Link Networks). The experiences were conducted at LSP/COPPE Laboratory in a Stairmand high efficiency prototype (Dc = 5 cm) with variable overflow diameter. Three different configurations were tested, and it is possible to observe a significant increase in the collection efficiency with the reduction of the overflow diameter.

Results gathered from the literature on the dynamics of bubbles in liquid are correlated by means of a formulation traditionally employed to describe the dynamics of isometric solid particles. It is assumed that the shape of the bubble depends, by means of the Eotvos number, on its diameter and on the gas-liquid surface tension. The analysis reported herein includes the dynamics of the isolated bubble along with wall and concentration effects. However, the effects of gas circulation in the bubble, which result in terminal velocities higher than those of a rigid sphere, are not being considered. A limited number of experimental points are obtained employing a modified version of the Mariotte flask which permits the precise measure of bubble volume. A classic bubble column is also employed in order to measure gas holdup in the continuous phase. Experiments were carried out employing air, with distilled water, potable water, water with variable amounts of surfactant and glycerin as the liquid phase.