Direct Contact Membrane Distillation (DCMD

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