Numerical Investigation of Hydrodynamics in Inline Mixers

Abstract

The utilization of inline mixers for continuous fluid mixing is a common practice in chemical industries. Information related to hydrodynamics condition in inline mixers is found to be limited while it is crucial for inline mixer type selection. Evaluation of hydrodynamic characteristics in several commercial inline mixers is analyzed in this study, including Y-type, T-type, elbow type, and internal injection mixer types. The analysis is conducted using computational fluid dynamics (CFD) for various Reynolds number conditions from 5,000 to 200,000. Mesh independence tests and model validation with experimental results are performed to ensure simulation accuracy. The CFD results showed that the Y-type mixer type provides the shortest distance i.e., about 12 times diameter. The internal injection type mixer has the most extended hydrodynamic region length to reach a fully-developed region for the same Reynolds number. The highest wall stress is indicated by the injection inline mixer type that located at the outer side wall of the injection pipe. The wall stress at that region is observed to be around twice as large compared to the other mixer type. Meanwhile, the mixer joint in the T-type and Y-type mixers were found to have a wall stress hotspot. Logarithmic correlation formulas were successfully formulated to correlate hydrodynamic region length and Reynolds number for all mixer types. The study results are essential in serving as the basis for inline mixer selection in the industrial sector