Orificing of steam separators for uniform flow distribution in riser area of steam generators

Claim 1

A shell-and-tube heat exchanger for the generation of vapor by the indirect transfer of heat from a heating fluid to a vaporizable liquid comprising a generally vertically elongated cylindrical shell, transversely extending tube sheet means dividing the interior of said shell into a vapor generating chamber and heating fluid chamber means, a vertical plate dividing the heating fluid chamber means into an inlet chamber and an outlet chamber, a bundle of U-shaped heat exchange tubes having their inlets connected to the inlet chamber and their outlets connected to the outlet chamber, for circulating heating fluid through said tubes, means for supplying vaporizable liquid to said vapor generating chamber, a separator deck extending transversely across said shell above the tube bundle, a plurality of openings in said deck, a plurality of water-steam separators having their inlets connected to the openings in the deck, some of the separator inlets located directly above the heating fluid inlet chamber being of smaller cross-sectional flow area than those above the heating fluid outlet chamber, and said some of the separator inlets having smaller cross-sectional flow area are those furthest removed from the heating fluid outlet chamber.