Application of low frequency vibration to degassing of highly viscous shear-thinning fluids

Abstract

The removal of unwanted gas bubbles is an important operation in many processes. In this paper, the mechanism of the degassing of highly viscous fluids by low-frequency vibration is studied numerically using the computational fluid dynamics (CFD). The effects of vibration frequency and amplitude on the degassing rate are investigated. The results show that the superimposed mechanical vibration largely affects the degassing rate of shear-thinning fluids but exerts no effect on that of Newtonian fluids. The de-gassing rate of shear-thinning fluids depends on the vibration frequency and amplitude. What's more, low-frequency and small-amplitude vibration is particularly useful in re-moving gas bubbles from viscous shear-thinning fluids, however, high-frequency or large-amplitude vibration may intensify air entrapment and brings new gas bubbles into fluids.