Abstract: The steam generator (1) comprises a first normal feed water device (8) and a second emergency feed water device (16) of the steam generator, comprising, respectively, a first toroidal header (10) and a second toroidal header (17) arranged coaxially with respect to the outer jacket (2b) of the steam generator. The second toroidal header (17) of the second emergency feed water device (16) placed inside the upper cylindrical part (2b) of the outer jacket comprises, fastened to each of a set of openings penetrating an upper part of its toroidal wall, a water injection tube (22) having an open lower end part fastened to the opening of the toroidal wall, a straight part inclined with respect to the vertical axial direction in the direction of a central part of the steam generator and an open upper end at the end of the straight part of the tube (22) for injecting emergency water inside the steam generator.

Abstract: The steam generator includes a feedwater delivery device at an upper axial end of an annular space between an outer shell and a bundle wrapper of the steam generator. The feedwater, delivery device includes a header (11) having a shell of toroidal general shape, at least one feed pipe for the header and feedwater distribution means (14) in the upper part of the annular space of the steam generator. The feedwater distribution means (14) include a plurality of openings (17) that pass through the upper part of the shell of the toroidal header (11) and are distributed circumferentially on the wall of the header and a plurality of tubes (15) fixed via a lower end part at an opening (17) of the header (11). Each of the straight tubes (15) includes an upper end part through which openings (20), such as water passage slots, pass and a cap (16) fixed to the upper end of the tube (15) surrounding, with a radial clearance, the upper end part of the tube (15).

Abstract: The steam generator includes a feedwater delivery device at an upper axial end of an annular space between an outer shell and a bundle wrapper of the steam generator. The feedwater, delivery device includes a header (11) having a shell of toroidal general shape, at least one feed pipe for the header and feedwater distribution means (14) in the upper part of the annular space of the steam generator. The feedwater distribution means (14) include a plurality of openings (17) that pass through the upper part of the shell of the toroidal header (11) and are distributed circumferentially on the wall of the header and a plurality of tubes (15) fixed via a lower end part at an opening (17) of the header (11). Each of the straight tubes (15) includes an upper end part through which openings (20), such as water passage slots, pass and a cap (16) fixed to the upper end of the tube (15) surrounding, with a radial clearance, the upper end part of the tube (15).

Abstract: The steam generator (1) comprises a first normal feed water device (8) and a second emergency feed water device (16) of the steam generator, comprising, respectively, a first toroidal header (10) and a second toroidal header (17) arranged coaxially with respect to the outer jacket (2b) of the steam generator. The second toroidal header (17) of the second emergency feed water device (16) placed inside the upper cylindrical part (2b) of the outer jacket comprises, fastened to each of a set of openings penetrating an upper part of its toroidal wall, a water injection tube (22) having an open lower end part fastened to the opening of the toroidal wall, a straight part inclined with respect to the vertical axial direction in the direction of a central part of the steam generator and an open upper end at the end of the straight part of the tube (22) for injecting emergency water inside the steam generator.

Abstract: The steam generator comprises a cylindrical outer jacket (2) arranged with its axis vertical, a bundle wrapper (4) arranged coaxially with respect to the outer jacket and a space (9) in which feed water can flow between the bundle wrapper (4) and the outer jacket (2) or a guide skirt (8, 8a). A water supply device (10) placed towards the top of the space (9) in which the feedwater flows comprises a torus-shaped manifold (12), the upper wall of which is traversed by a number of flow openings (18) distributed in the circumferential direction of the manifold (12). A feed pipe (13) opens into the manifold and the feedwater is guided by a guide device towards the annular flow space (9). Radial dividing walls (19a, 19b, 19c, 19d) are arranged transversely in a water flow space delimited between the manifold (12) and the guide device (14).

Abstract: In a preheating steam generator, the feed water is distributed in a feed space (34) by inverted J-shaped tubes (50), so as to mix with the recirculation water passing out of the water-steam separators, which ensures the preheating of said feed water. In order to prevent the latter rising again above the upper edge (30a) of skirt (30) externally defining the space (34), use is made of one or more of the four procedures consisting of partly obstructing by a plate (52) the top of space (34), downwardly extending tube (50), increasing the diameter in the vicinity of their end and upwardly extending skirt (30).