Recovery of gas dissolved in flue condensate

Claim 1

A method for removing volatile gas from a liquid, comprising the steps of: providing a double wall chamber, the walls of the chamber being formed of thermally conductive material, the outer surface of the outer wall being directly contacted by refrigerant conduit means and the inner wall forming an inner chamber within said outer chamber, said inner chamber being divided by a plurality of perforated horizontal members into a vertically extending array of sub-stages, each of said sub-stages communicating with an annular space formed between the inner wall and the outer wall by a plurality of holes in the inner wall, the number of the holes in the inner wall forming the inner chamber varying from one sub-stage to the next such that the overall area for gas flow from each sub-stage provided by the holes in the inner wall increases progressively from the top to the bottom of the array of sub-stages, an aperture being formed in the top of the inner chamber for introducing the liquid having a volatile gas dissolved therein, a drain at the bottom of the inner chamber for removing liquid therefrom and a drain at the bottom of the annular space between the inner and outer walls for removing condensed volatile gas therefrom; supplying a refrigerant to said refrigerant conduit means to chill the outer wall of the vessel; introducing the liquid with volatile gas dissolved therein through said inlet at the uppermost portion of said vessel; allowing said liquid to flow gradually downwardly through said sub-stages; applying a vacuum to the annular space between the inner and outer walls, such that the volatile gas is removed from the liquid in each of the sub-stages, the aggregate area of the holes in the inner wall varying from one sub-stage to the next in a manner such that essentially equal amounts of volatile gas are withdrawn through the holes in each of the sub-stages; and withdrawing the condensed volatile material from the drain at the bottom of the annular space between the inner and outer walls of the vessel.

Claim 2

A method for removing volatile gas from a liquid, comprising the steps of: providing a double wall chamber, the walls of the chamber being formed of thermally conductive material, the outer surface of the outer wall being directly contacted by refrigerant conduit means and the inner wall forming an inner chamber within said outer chamber, said inner chamber being divided by a plurality of perforated horizontal members into a vertically extending array of sub-stages, each of said sub-stages communicating with an annular space formed between the inner wall and the outer wall by a plurality of holes in the inner wall, the number of the holes in the inner wall forming the inner chamber varying from one sub-stage to the next such that the overall area for gas flow from each sub-stage provided by the holes in the inner wall increases progressively from the top to the bottom of the array of sub-stages, an aperture being formed in the top of the inner chamber for introducing the liquid having a volatile gas dissolved therein, a drain at the bottom of the inner chamber for removing liquid therefrom and a drain at the bottom of the annular space between the inner and outer walls for removing condensed volatile gas therefrom; supplying a refrigerant to said refrigerant conduit means to chill the outer wall of the vessel; introducing the liquid with volatile gas dissolved therein through said inlet at the uppermost portion of said vessel; allowing said liquid to flow gradually downwardly through said sub-stages; applying a vacuum to the annular space between the inner and outer walls, such that the volatile gas is removed from the liquid in each of the sub-stages, the aggregate area of the holes in the inner wall varying from one sub-stage to the next in a manner such that essentially equal amounts of volatile gas are withdrawn through the holes in each of the sub-stages; and withdrawing the condensed volatile material from the drain at the bottom of the annular space between the inner and outer walls of the vessel.