Heat exchanger using thermal convection tubes

Claim 1

A heat exchanger system for use in generating steam with heat from a sodium fluid which has been heated in a nuclear reactor, including in combination, a first chamber coupled to the reactor for receiving said sodium fluid therefrom, said first chamber having a top wall, a second chamber positioned above said first chamber with said top wall of said first chamber forming the bottom wall of said second chamber, said top and bottom wall forming a separation wall between said top and bottom chambers, said second chamber further containing water, a plurality of sealed hollow members each having an upper portion and a lower portion, each of said sealed hollow members being placed in a substantially vertical position and extending through said separation wall with said lower portion in said first chamber and said upper portion in said second chamber, said sealed hollow members being mechanically secured to said separation wall at the middle portion of said sealed hollow members, each of said sealed hollow members being in the form of a first tube having sides and closed bottom and top ends, with said lower portion thereof being substantially filled with liquid mercury, a second tube having open top and bottom ends and centrally located with reference to said sides of said first tube, said bottom end of said second tube being spaced away from said bottom end of said first tube, said top end of said second tube being positioned below the surface of said liquid mercury in said lower portion of said sealed hollow member, said heated sodium acting to heat said liquid mercury to form a mercury gas, said mercury gas rising to said upper portion and transferring heaT to said water while in said upper portion to generate steam in said second chamber, said gas condensing to liquid mercury after said heat transfer and returning to said lower portion, said second tube acting as a downcomer to promote circulation of said liquid mercury in said lower portion.