Patent ID: 7096666

Claim:
An air-cooled condensing system, comprising: a first stage condenser comprising a plurality of air-cooled fin tubes connected in parallel and each having an upper end and a lower end, a first steam distribution header connected to supply steam to both ends of the tubes, whereby an upper condensing (K) section and a lower dephlegmator (D) section are formed in each tube, whereby condensate forming in the K section flows down each tube in the same direction as the incoming steam and condensate in the D section of the tube flows against the direction of the incoming steam; at least one steam extraction duct connected to the first stage condenser for extraction of steam which is not condensed in the first stage condenser; a second stage condenser comprising a plurality of air-cooled fin tubes connected in parallel and each having an upper end and a lower end, and a second steam distribution header at the lower end of the second stage condenser; and the steam extraction duct of the first stage condenser being connected to the second steam distribution header, whereby the second stage condenser operates as a dephlegmator (D) section.