Patent ID: 7537200

Claim:
An apparatus for controlling the dissolved gas content of an aqueous liquid containing dissolved gas, comprising a microporous hydrophobic hollow fibre membrane, to provide at equilibrium a stable interface between an aqueous liquid phase containing dissolved gas on a first side of the membrane and a gaseous phase on an opposite side of the membrane, means providing aqueous liquid phase and gaseous phase flow paths on opposite sides of the membrane, means for supplying an aqueous liquid phase containing dissolved gas to the first side of the membrane, means for controlling the flow feed rate of the aqueous liquid phase, means for controlling the aqueous liquid phase inlet pressure, means for supplying a gaseous phase to the other side of the membrane, means for removing gaseous phase from the apparatus, means for removing aqueous phase from the apparatus, and differential pressure control means for controlling the inlet pressure of the gaseous phase, whereby the gaseous phase pressure is up to but not exceeding the aqueous phase pressure, and in operation the simultaneous mass transfer through the membrane of a first gas in the gaseous phase into the liquid phase and of a second gas dissolved in the aqueous liquid into the gaseous phase occurs, so that the gas content of the first gas in the aqueous phase is increased, the gas content of the second gas in the gaseous phase is decreased and the total gas pressure of the aqueous phase is altered.