Cleaning vertical steam generator drum contg. tube nest - using liquid entering at centre removed from tube bottom, and spray moved radially

摘要

The arrangement is intended for removing sediment from a steam generator (in a nuclear power plant) containing a tube nest (through which the heating medium passes) in a vertical drum (1). The nest consists of U-tubes whose ends are fixed in a tube bottom (2) and the drum wall has openings (11,14) through at least one (11) of which cleaning liquid is introduced and removed (14) so that it flows across the bottom whilst a pressure spray head (15, via 11) introduces further liquid. The first liquid is introduced (via 11,19,20,18) near the centre of the bottom and removed at at least two points at opposite sides (via 14,21) just above the bottom, whilst the spray head is radially moved at least once from the centre to the drum wall.FL.