Abstract: A nuclear power system comprises a plurality of modules disposed in below-grade pits to provide a compact, self-contained nuclear power supply. The modules are preferably individually transportable so that they may be substantially preassembled prior to installation. The system operates at relatively low temperatures and pressures, and includes various safety features which would prevent radioactive contamination of the surrounding environment in the event of a disturbance causing rupture of one or more of the odules or the pipes interconnecting the modules. The system also provides a low resistance flow path for vapor discharged from the turbine to improve efficiency.

Abstract: Apparatus for effecting mass transfer between liquid and gas phases includes a chamber having a tube bundle therein comprised of a plurality of spiral fluted tubes maintained in upstanding relation by transverse tube sheets. Relatively short tubular inserts cooperate with the opposite ends of the spiral fluted tubes in a manner to facilitate passage of liquid downwardly through each tube in the form of a liquid film on the interior spirally fluted tube surfaces, and enable passage of gas upwardly through each tube such that the gas directly contacts the liquid film and effects mass transfer therebetween. Inlet and outlet coolant passages enable coolant to be introduced into the chamber for removing heat of absorption from the external surfaces of the tubes.

Abstract: Heat exchange apparatus comprises a generally cylindrical tank having an inlet port for entry of gas and an outlet port for exit of the gas after it is cooled, and an annular bundle of tubes disposed within the tank. The tank includes a cylindrical side wall or shell which encloses the tube bundle, and upper and lower annular manifolds for controlling flow through the tube interiors. The annular tube bundle has a generally cylindrical interior having a longitudinal axis parallel to that of the shell. The interior of the annular tube bundle defines an inner plenum which communicates with one of the ports. The annular tube bundle is radially offset from the center of the tank to define an eccentric outer plenum which communicates with the other port.

Abstract: Heat exchange apparatus comprises a generally cylindrical tank having an inlet port for entry of gas and an outlet port for exit of the gas after it is cooled, and an annular bundle of tubes disposed within the tank. The tank includes a cylindrical side wall or shell which encloses the tube bundle, and upper and lower annular manifolds for controlling flow through the tube interiors. The tank inlet port is located centrally of the upper annular manifold, and the tank outlet port is located on the shell. The annular tube bundle has a generally cylindrical interior having a longitudinal axis parallel to that of the shell. The interior of the annular tube bundle is aligned with the inlet port so that the interior of the tube bundle functions as an inlet plenum for the gas entering the recuperator.

Abstract: A method and apparatus for forming a spiral tube from a length of metallic strip material wherein the strip is fed through a closed tube forming die operative to form the strip into a spirally wound tube having its longitudinal edges in juxtaposed relation. Driven torque wheels carried on one or more support carriages downstream from the forming die are operative to engage the outer peripheral surface of the tube to prevent springback and enable selective control of the relation between juxtaposed edges of the strip as it is passed longitudinally through a welding station during which the juxtaposed edges are welded to form a continuous leak-proof seam. The metallic strip may be planar or have longitudinal flutes formed therealong.

Abstract: A spirally fluted metallic heat transfer tube is disclosed wherein the finished tube has improved heat transfer performance through the provision of a predetermined number range of multiple start continuous helical flutes formed along its longitudinal length, the flutes having specific helix angle relation and flute height to tube hydraulic diameter ratio so as to establish a ratio of thermal diffusivity to momentum diffusivity greater than 1.

Abstract: A vapor generator and heat exchanger, particularly suited for use in a substantially cylindrical cavity in a pressure vessel includes high and low temperature sections of the vapor generator positioned coaxially with the annular outer section terminating a distance from the end of the central or axial section to form at the one end an annulus arranged between the central or axial section and the pressure vessel wall. A plurality of reheater or heat exchanger sections and various inlet and outlet conduits are positioned in the annulus. A heating fluid is directed first transversely over the tubes of the reheater sections, then along the tubes of the central or axial high temperature section after passing over the outer annular low temperature section.