Patent ID: 7931782

Claim:
A method of recovering a liquid medium from a mixture containing the liquid medium, the method comprising: contacting the mixture comprising the liquid medium with a first gas to vaporize the liquid medium in a vaporizing means and thereby to form a second gas which is a mixture of the first gas and vaporized liquid medium, and feeding the second gas into a condensing means to condense the vaporized liquid medium and separate the first gas; using the first gas separated from the liquid medium by condensation as the first gas to be contacted with the liquid medium; and regulating the partial pressure of the vaporized liquid medium in the vaporizing means by a partial pressure regulating means; wherein the condensing of the second gas in the condensing means comprises partially condensing the vaporized liquid medium in a first condensing means, and further cooling and completely condensing the vaporized liquid medium in a second condensing means; and returning a part of the first gas and the vaporized liquid medium discharged from the vaporizing means through a conduit means in the partial pressure regulating means to the vaporizing means while flowing together with the separated first gas without passing through the first condensing means and the second condensing means and regulating the partial pressure of the vaporized liquid medium by controlling the flow rate of the vaporized liquid medium returning to the vaporizing means through the conduit means, wherein the recovery of the liquid medium is carried out where the first gas is circulated through a closed system under reduced pressure; or vaporization is carried out at a temperature of the boiling point or lower of the liquid medium when the liquid medium is vaporized; or the recovery of the liquid medium is carried out where the first gas is circulated through a closed system under reduced pressure and vaporization is carried out at a temperature of the boiling point or lower of the liquid medium when the liquid medium is vaporized.