Modeling of pore wetting in vacuum membrane distillation

In this work simulation results for the pore wetting of vacuum membrane distillation (VMD) are reported, considering heat and mass balance at liquid/vapor interface when steady state is achieved. Two cases were studied. In case 1, the system is in isothermal condition. In case 2, heat enters only from the pore inlet and is removed at the liquid/vapor interface as liquid vaporizes. The simulation has shown that the liquid/vapor boundary may remain inside the pore at the steady state condition, which means the partial pore wetting is possible. The significant temperature drop from the pore entrance to the liquid/vapor interface has also been predicted. It was found from case 2 simulation that VMD is possible in a wider range of pore radius, r, than the Laplace equation predicts. As well, the possibility of VMD for the contact angle (theta) below 90 degrees was justified.