Steam raising heat exchanger for sodium cooled reactor - has sliding joint in stuffing box, backing up bellows

摘要

A heat exchanger for the indirect transference of energy from a heating liq. to a fluid to be heated, comprises an elongated vessel, standing vertically and upper press. There is an outlet connection for the heated fluid, close to one end, and the vessel contains two tube header plates. These are some distance apart axially; one being secured to the wall of the vessel, whilst the other forms part of a floating head, delimiting an antichamber to the outlet for the heated fluid. A gp. of tubes arranged parallel to each other are attached at their ends to the header plates, and the heating fluid is circulated round them. From the floating head a tubular extension slides in an opening in the one end of the vessel. A cylindrical bellows has one end welded to the tubular outlet for the steam and the other welded to the vessel. Outside the bellows, a sliding joint is included in a stuffing box assembled between the tubular extension of the floating head and the vessel. Those follows the relative longitudinal motion of the tube and the vessel and forms a second line of defence, preventing any leakage of fluid from inside the vessel in case the bellows should burst. The tubular extension and the vessel flange hase an arrangement of splines and grooves allowing axial motion without any turning, so as to avoid damage to the bellows.