SYSTEM FOR FYLLNING OCH TOMNING AV VERMEVEXLARE

1390529 Heat exchangers TRANSELEKTRO MAGYAR VILLAMOSSAGI KULKERESKEDELMI VALLALAT 31 Oct 1972 [5 Nov 1971] 50182/72 Heading F4S A system, for filling and emptying a series of air-cooled multipass heat exchangers 8 connected in parallel between a supply conduit 6 and a return conduit 7 and used to cool turbine power plant cooling water, comprises a drain conduit 17 branching off the supply conduit 6, and an inclined conduit 9 connecting the supply conduit 6 with the return conduit 7. Each conduit 6, 7 and 17 has a respective shut-off valve 1, 2 and 3, and automatic vent valves 5 are provided on top of the heat exchangers. The conduit 9 incorporates a flap valve 4 which permits a flow from the return conduit 7 into the supply conduit 6 but prevents a flow in the opposite direction. When the heat exchangers are to be emptied, shut-off valves 1 and 2 are closed and valve 3 is opened so that water will be drained from the exchangers through conduits 7 and 9 and through conduit 6 to the drain conduit 17; ambient air is permitted to enter through valves 5 to prevent the generation of a vacuum in the system. When the heat exchangers are to be filled up, valve 3 in drain conduit 17 is closed and valve 2 in return conduit 7 is opened; water supplied through valve 2 will then enter the exit sides of the exchangers via conduit 7 and the inlet sides via conduit 9 and conduit 6. To ensure automatic operation of the system, the valves 1, 2 and 3 may be connected to a program control unit (12, Fig. 3, not shown) via actuators (13, 14 and 15). The control unit (12) may be connected to a sensor (16, Fig. 4, not shown) for ascertaining the level of water in the heat exchangers.