A novel design of an air gap membrane distillation (AGMD) module was proposed to
enhance the permeate flux improvement for the desalination of pure water productivity. The modeling
equations for predicting permeate flux in the AGMD module by inserting Λ-ribs carbon-fiber open
slots under various hydrodynamic angles were developed theoretically and experimentally. The
temperature distributions of both hot and cold feed streams were represented graphically with the
hot saline flow rate, inlet saline temperature, and carbon-fiber hydrodynamic angles as parameters.
The results showed a good agreement between the experimental results and theoretical predictions.
Designed by inserting Λ-ribs carbon-fiber open slots into the flow channel, the membrane distillation
module was implemented to act as an eddy promoter and yield an augmented turbulence flow.
The effect of Λ-ribs carbon-fiber open slots not only assured the membrane stability by preventing
vibration but also increased the permeate flux by diminishing the temperature polarization of the
thermal boundary layer. The permeate flux improvement by inserting Λ-ribs carbon-fiber open
slots in the AGMD module provided the maximum relative increment of up to 15.6% due to the
diminution of the concentration polarization effect. The experimental data was incorporated with
the hydrodynamic angle of Λ-ribs carbon-fiber open slots to correlate the enhancement factor with
the Nusselt numbers to confirm the theoretical predictions. The accuracy derivation between the
experimental results and theoretical predictions was pretty good, within 9.95 ≤ E ≤ 1.85. The
effects of operating and designing parameters of hot saline flow rate, inlet saline temperature, and
hydrodynamic angle on the permeate flux were also delineated by considering both the power
consumption increment and permeate flux enhancement.