(267c) Experimental and Analytical Investigation of the Effect of Membrane Thickness Together with a Critical Commentary on MD Analysis

An analytical model was created to estimate the optical membrane thickness for DCMD operations. It is found that the value of optimal thickness increases with reduced heat transfer coefficients; decreased feed inlet temperature; increased membrane permeability; and increased salinity. PVDF electro-spun membranes, consolidated with a heat press process, as thin as 27 microns were fabricated and tested in a DCMD cell.  A transmembrane flux as high as 60 L/hr m² was observed. Except for the thinner membranes with high inlet feed temperatures, the fit of the model was excellent provided due allowance was made for the measured variation in porosity with thickness.  The utility of describing deviations from ideal performance in terms of a Temperature Polarisation Coefficient is questioned and an alternative approach will be proposed.