Effects of different propeller blades on gas-liquid two-phase mixing characteristics in stirred reactor

A stirred reactor is a device that supplies mechanical energy to a stirred medium by obtaining a suitable flow field. It is widely used in industrial production, especially in the chemical industry, and many chemical production applications are more or less affected by the effect of stirring. Due to the lack of data on the design parameters of propeller blades at home and abroad, the profile of propeller blades is poor, and the stirring performance needs to be improved. In order to study and compare the stirring effect of several propeller blades, the propelling blade of the stirred reactor is taken as the research object, and polymerization medium of the mixing reactor is simplified to water and gas. First, the propeller blades are designed according to the design parameters. Four different types of propeller blades are designed by using different helix angles and contour shapes. Then, three-dimensional diagrams of the four propelled stirred reactors are drawn and unstructured meshing is performed according to the two-dimensional diagrams. Finally, the internal flow characteristics of the four propelled stirred reactors were simulated and analyzed by using multiple reference frames, VOF multiphase flow models, and RNG k-Ε turbulence models. When the speed is 400 r/min, we qualitative analyze the distribution and uniformity of radial velocity and the mixing degree through comparing radial velocity cloud graph and the variation of gas volume fraction cloud graph from 0 to 18 s (including 0.6 s, 6 s, 12 s and 18 s). Besides we also define the dimensionless gas volume fraction and axial velocity, so 0 to 18 s (including 0.6 s, 6 s, 12 s and 18 s) hybrid rate, distribution of the gas volume fraction and the rate of change of the axial velocity are quantitative analyzed. According to the results of numerical simulation, the mixing characteristics and mixing degrees of the four types of propelled stirred reactors were compared. We can draw the following conclusions the asymmetric blades with variable spiral angle (FDC-450-γ) has a more uniform flow rate, the mixing rate is faster and the mixing degree is better. In this paper, four different propeller blades are selected for comparison and analysis, which lays the foundation for subsequent research and engineering practice. © All Right Reserved.