(42ah) Computational Fluid Dynamics Simulation of Baffle Effects in Non-Circular-Channeled Microfiltration Membranes

Non-circular-channeled microfiltration membranes have been successfully applied commercially. The irregular-shaped channels, e.g., star-shaped channels, can induce turbulence and reduce membrane fouling—a major problem in membrane-based separation (Chiu et al. 2006). In addition, it has more surface area for filtration while providing higher flow rate due to lower cross-sectional area compared with a circular channel of the same diameter. This results in lower energy required from the pump (Mantec Technical Ceramics Ltd., 2009). However, it was found that stagnant areas could occur in the non-circular channels (Chiu et al. 2006). Chiu and James (2006) later proposed baffle insertion into the channels to reduce the stagnant areas and enhance turbulence. Nonetheless, some baffles were found to suppress the turbulence.

This study investigated flow behavior and membrane fouling as affected by non-circular-shaped channels and baffle integration in a membrane microfilter extensively using computational fluid dynamics (CFD) modeling. The CFD model was validated with the published empirical data and good agreement was found. The results will be used to guide the design of baffles and membrane microfilter structure to achieve optimal permeation flux and reduce energy consumption.

References

Chiu T.Y., Lara Dominguez M.V., and James A.E., 2006, Critical flux and rejection behaviour of non-circular-channelled membranes: influence of some operating conditions, Sep. Purif. Technol., 50, 212-219.

Chiu T.Y. and James A.E., 2006, Effects of axial baffles in non-circular multi-channel ceramic membranes using organic feed, Sep. Purif. Technol., 51, 233-239.

Mantec Technical Ceramics Ltd., 2009, Case study: microbial control of botanical extracts using Star-Sep™ ceramic crossflow microfiltration, available at www.mantectechnicalceramics.com, accessed on 24.03.2014.