Experimental study of gas-liquid two-phase bubbly flow characteristics in a static mixer with three twisted leaves

摘要

Under the conditions of liquid phase inlet Re ranging from 9,836 to 56,206 and gas fraction a from 4.76% to 66.67%, gas-liquid two-phase bubbly flow was investigated in a static mixer with three twisted leaves (TKSM) with a diameter of 100 mm and an aspect ratio of 1.5. A high-speed camera Revealer-2F04M with a resolution of 1,920x1,080 pixels was used to capture the evolution of bubble groups at the different axial windows of mixer elements. The results show that the flow pattern in the TKSM is still in bubbly flow at the flow rate of continuous phase Q(L) no more than 1.0 m(3)/h and gas fraction alpha higher up to 54.55%-66.67%. The Sauter mean diameter d(32) of bubble groups gradually decreased with the increase of the mixing elements number. With the given liquid flow rate Q(l)= 1.0 m(3)/h, the Sauter mean diameter d(32) firstly decreased and then increased with the increase of gas flow rate. The local minimum of d(32) was obtained at Q(G)=0.72m(3)/h and 84.5% of the d(B)/D-0 is in the range of 0.02-0.05. The relationship among Sauter mean diameter, the inner diameter and the non-dimensional residence time tau satisfies the correlation We(0.35)center dot d(32)/D-0=0.026 tau(-0.17).