Abstract:
Direct Contact Membrane Distillation (DCMD) is one of the most commonly used
configurations of membrane distillation technology for water desalination. Our project
mainly comprised of making a working pilot model of DCMD. It contains two tanks; one
for the feed water and the other for permeate water. Feed tank contains the saline water
which is pumped into a membrane module for desalination. The membrane module
consistsof four aluminum plates with a hydrophobic membrane sandwiched in between
them. The membrane doesn’t allow water to pass through it while allows vapors to pass.
One side of the module contains the heated feed water while the other contains the clean
distilled water (permeate) separated by the membrane. Permeate water is pumped by a
small pump in the membrane module. The vapors from the feed water pass through the
membrane and condense to become part of the permeate side.
The membrane module consists of a diffusion chamber engraved in the middle plates
with the membrane sandwiched between them held in place by rubber cork, which acts as
a sealing gasket as well as helps in keeping the module and membrane in place. The
diffusion chamber prevented the water flowing into the module from striking the
membrane directly and made the water flow in a laminar fashion across the membrane.
This not only increases the membrane life but also provides higher permeate flux at lower
temperatures
