The spacer grids for heating elements and in particular for nuclear fuel rods

摘要

998,625. Heat exchanger tube supports. UNITED KINGDOM ATOMIC ENERGY AUTHORITY. Aug. 28, 1963 [Sept. 5, 1962; May 31, 1963], Nos. 34022/63 and 22023/63. Divided out of 998,624. Heading F45. [Also in Division G6] A spacer grid for holding a plurality of rodlike heating elements on parallel axes equispaced round a circle comprises inner and outer closed shape members between which are disposed an endless length of metal strip bent to contact alternately the inner and outer members so as to define with the outer member cells to receive the elements. All the embodiments described relate to nuclear fuel element assemblies, although it is stated that the invention is applicable to heat exchanger structures. Five fuel rods 16 are disposed round a central piston rod 20 (see Specification 998,624), and are held in position between a strip 23 and a hoop 25. In a modification (Fig. 4, not shown), the lobes 23 extend beyond a circle circumscribing the outermost points on the fuel rod circumferences, so that they do not contact the hoop 25; the fuel rods are brazed to the inner member 23. In a further modification, Fig. 5, the inner member 30 has stiffeners 32, and the outer member includes integral tags 33 sheared and displaced from the material of the outer member 36. The embodiments described may form spacer grids for series of concentric rings of fuel rods.