Eulerian-lagrangian modeling and computational fluid dynamics simulation of wire mesh demisters in MSF plants

Abstract

This study focuses on computational fluid dynamics model (CFD) for simulation of demisters in multistage flash desalination (MSF). The Eulerian-Lagrangian model (steady-state and two-dimensional) was developed to simulate the demister. The model was used to simulate the flow of water vapor and brine droplets in the demister. The computational domain includes the following three zones: the vapor space above the demister, the vapor space below the demister, and the demister. The demister zone was modeled as tube banks. A sensitivity analysis of the model revealed that vapor velocity is the main parameter that affects demister performance. Additionally, the analysis indicated that vapor temperature had no effect on the pressure drop across the demister. The developed model was validated using data from both the literature and real MSF plants. Analysis indicated that model predictions and experimental data were consistent. This work gives extensive details for CFD modeling of the MSF demister. The work is based on a previous study by Al-Fulaij et al. (2014). This work is part of a group effort to develop a comprehensive CFD simulation for the entire flashing stage of the MSF process, which would provide an extremely efficient and inexpensive design and simulation tool to the desalination community.