Study on the performance of double-pipe air gap membrane distillation module

• A novel double-pipe air gap membrane distillation module was developed successfully.
• The air gap width of the module can be evenly distributed and easily regulated.
• The concept of equivalent membrane distillation flux (JAGMD) was firstly introduced.
• The maximum value of J, GOR and JAGMD could reach 11.4 kg/(m2·h), 6.6 and 29.6 kg/(m2·h), respectively.

Air gap width has an important influence on the performance of air gap membrane distillation (AGMD) process. In this study, a novel double-pipe AGMD module (DP-AGMD-M) consisted of PVDF hollow fiber membrane and heat exchange capillary copper tubes was successfully developed. The evenly distribute and easily control of the air gap width in DP-AGMD-M can be implemented. The effect of the air gap width (da), hot feed temperature (T1), hot feed flow rate (Q), temperature difference (ΔT) between the hot feed outlet temperature and the cold feed inlet temperature, and the effective membrane module length (L) on the performance of DP-AGMD-M were experimental studied. The concept of the equivalent membrane distillation flux (JAGMD) was firstly introduced in this paper and used to evaluate the comprehensive performance of DP-AGMD-M. The optimal performances, including membrane distillation flux (J), gained output ratio (GOR) and JAGMD were obtained. Within the experimental range, the maximum J arrived at 11.4 kg/(m2 · h), the maximum GOR reached 6.6 and the maximum JAGMD was 29.6 kg/(m2 · h).

Configuration of DP-AGMD-M.Figure optionsDownload as PowerPoint slide