Description
The PMI Pervaporation machine is capable of measuring rate of formation of water from salt solutions under a
wide variety of experimental conditions including pressure, flow rate and temperature. Clean water may be
collected in flowing water, in flowing gas or under vacuum.
Salt water flows across one side and salt free water flows across the other side of hydrophobic membranes at
pressures less than the breakthrough pressure of the membrane. Water does not penetrate the pores of the
membrane. Salt free water is maintained at temperatures less than the temperature of the salt water. The vapor
pressure of salt free temperature water is lower than the vapor pressure of salt water. Water vapor flows from the
salt water side to the fresh water side, condenses in the salt free water and gets carried away from the membrane
by the flowing water. In place of salt free water, gases with low vapor pressure (low humidity) can flow across the
membrane.
The water vapor flowing through the membrane from the salt water side is carried away from the membrane by the
flowing gas. In place of salt free water or gas, vacuum is maintained on the other side of the membrane and water
vapor from the salt water flows to the vacuum chamber. The vapor can be collected from the vacuum side.
