| 摘要 |
957,815. Handling material in radio-active environment. UNITED KINGDOM ATOMIC ENERGY AUTHORITY. Feb. 12, 1963 [March 21, 1962], No. 10913/62. Heading B4Q. [Also in Division G6] Apparatus for replacing an impeller in a reactor system of the kind in which a gaseous coolant under pressure is circulated through the reactor core and at least one heat exchanger by at least one blower and an impeller of the blower is disposed within a pressure vessel surrounding the reactor core and/or the heat exchanger so that the diffusing casing of the blower is also within the pressure vessel, comprises a shielded flask having an aperture through which an impeller can pass, an impeller support platform so mounted within the flask that it is rotatable about a horizontal axis with an impeller on both sides of the platform and can present either side to the flask aperture, means for sealing the flask about an aperture, in a pressure vessel with the aperture on the flask in register with the aperture in the pressure vessel, means for purging the flask, and means on the platform for raising and for lowering an impeller through the apertures from and on to the support platform. In Fig. 1 the spherical shielded flask 10 is mounted on a trolley 11 and contains a rotatable platform 14 which is able to support on each side an impeller and its associated skirt on jacks 26, 27. To replace an active impeller 15a, jacks 26 are raised and attached to the skirt 16a; the skirt 16a is disconnected from the heat exchanger shell 22 and the neck portion 19 of the flask 10 is raised to make a joint with the flange 20. The jacks 26 lower the impeller on to the platform 14 which is rotated through 180 degrees to allow the fresh impeller 15b to be raised by jacks 27 into the heat exchanger shell. The flask 10 is purged with air, the neck portion 19 is lowered, and a permanent joint is made between the flange 20 and skirt 16b. The jacks 27 are disengaged from the skirt 16b and the flask 10 is wheeled away with the active impeller in a shielded hemisphere below the platform 14. |
