Interconnection arrangement for a dual temperature isotope exchange

An interconnection arrangement for two stages of a dual temperature isotope exchange apparatus for production of water enriched in deuterium comprising:

• a. a first stage including a cold tower, a dehumidifier, a hot tower, a humidifier, piping means for passing hydrogen sulphide gas through the humidifier, hot tower, dehumidifier, cold tower and recycling to the bottom of the humidifier, a liquid inlet feed to the top of the cold tower, and piping means for passing the liquid from the bottom of the cold tower through the dehumidifier, the hot tower, and the humidifier to a first stage output,
• b. a second stage including a cold tower, a dehumidifier, a hot tower, a humidifier, piping means for passing hydrogen sulphide gas through the humidifier, hot tower, dehumidifier, cold tower and recycling to the bottom of the humidifier, a liquid inlet feed to the top of the cold tower, and piping means for passing the liquid from the bottom of the cold tower through the dehumidifier to a second stage output,
• c. a first heat exchanger,
• d. a second heat exchanger,
• e. a third heat exchanger,
• f. means for taking a minor proportion of the liquid from the first stage output, passing generally equal fractions of this through the said first, second and third heat exchangers in parallel, recombining the fractions and returning to the piping means at a location between first stage hot tower and humidifier,
• g. means for taking a minor proportion of the liquid from the piping between first stage dehumidifier and hot tower, passing a major proportion of this through the first heat exchanger and returning to the top of the second stage humidifier,
• h. means for taking a minor proportion of the liquid from the piping between second stage dehumidifier and hot tower, passing this through the second heat exchanger, returning a major proportion to the top of the second stage dehumidifier, and passing the remainder to an output as product,
• i. means for passing the liquid from the second stage output to the top of the first stage dehumidifier, and
• j. means for taking a minor porportion of the liquid from the bottom of the second stage hot tower, passing through the said third heat exchanger and returning to the top of the second stage cold tower as liquid inlet feed.