Experimental Investigation of Heat Transfer Correlation for Direct Contact Membrane Distillation

This paper presents an experimental investigation of heat transfer in direct contact membrane distillation (DCMD) flow channels with and without the spacer. In this experiment, the usual hydrophobic membrane of DCMD is replaced by a copper plate to eliminate mass transfer. The study shows the most appropriate heat transfer correlations for empty channel cases with different channel heights and flow rates. For the case with the spacer in the flow channels, two spacer materials are investigated: nonwoven plastic and woven stainless steel. The paper presents the most appropriate heat transfer correlation for both these spacer materials. Further, the paper presents finding with two more spacer materials, woven fiberglass and aluminum spacer. It is found that the most appropriate heat transfer correlation for these materials is in the turbulent flow regime although the experimentally estimated Reynolds number suggests laminar flow is presented.