Effects of wavelength and number of bends on the performance of zigzag demisters with drainage channels

• Zigzag demisters with different number of bends and bend wavelengths were studied.
• The demisters with more number of bends have lower filtration sizes.
• Applying more number of bends causes a significant increase in the pressure drop.
• Demisters with small values of λ/S have more pressure loss and higher efficiency.
• For large wavelengths (λ/S>7.11), λ/S has small effect on the demister performance.

In this paper, the effects of number of bends and bend wavelength on droplet removal efficiency and pressure drop of a zigzag demister with drainage channels have been numerically investigated. A combination of Eulerian-Lagrangian method with eddy interaction model (EIM) has been used for the simulation of the droplet dispersion in turbulent gas flow. The droplet collection efficiency has been calculated and compared with available experimental data to show the validity of the simulation. The Reynolds stress transport model (RSTM) was applied to model the turbulent airflow. The results show that applying more bends in the demister reduces the filtration size of the demister but it can increase the pressure drop significantly. On the other hand, the demisters with small dimensionless bend wavelength have more pressure losses and higher droplet removal efficiencies.