DCMD modelling and experimental study using PTFE membrane

作者：Nakoa Khaled^*; Date Abhijit; Akbarzadeh Aliakbar

来源：Desalination and Water Treatment, 2016, 57(9): 3835-3845.

DOI：10.1080/19443994.2014.989272

• Membrane distillation
• Water desalination
• Membrane distillation coefficient
• Permeate mass flux

This research work aims to investigate the performance of direct contact membrane distillation (MD) unit under different conditions. A mathematical model was developed to evaluate the experimental values of the membrane water mass flux, heat transfer coefficients, the membrane/liquid interface temperatures, the temperature polarisation coefficient and the evaporation efficiency. This model was solved numerically using MATLAB((R)) software, and its results were used to predict the actual performance of the membrane unit. The MD coefficient was evaluated from the computer model data and was subsequently used to estimate water fluxes. Experimental tests were performed using 0.0572m(2) of PTFE membrane manufactured by membrane solution (85% porosity, 45m thickness, 0.22m nominal pore size). Feed solutions were aqueous NaCl solutions with 1,000-200,000mg/L (0.1-20%) in concentration and its temperatures were 40-80 degrees C, and feed flow rate was 2L/min. The temperature and flow rate of permeate water was fixed at 20 degrees C and 3L/min, respectively. The experimental observation showed that the vapour mass flux through the membrane pores increased with feed temperature, but decreased with feed concentration. It was found that the predicted mass fluxes agreed reasonably with the experimental data, except at a high feed concentration. The temperature polarisation coefficients increased with concentration and decreased with increasing temperature. The membrane heat transfer rates and the permeate flux have been discussed in this paper.

• 出版日期2016-2-19