GB827321A - Improvements in or relating to sealing devices - Google Patents

Abstract

827,321. Stuffing-box substitutes. UNITED KINGDOM ATOMIC ENERGY AUTHORITY. April 21, 1958 [April 25, 1957], No. 13215/57. Class 122 (5). [Also in Group XL (a)] A liquid seal between a rotatable cover plate 7, Fig. 2A, and a non-rotatable vessel 2 comprises a sleeve 6 which is formed on the plate and arranged to dip into a liquid contained in an annular cavity 4 provided in the vessel, the sleeve having a passageway 8 extending from a lower level on one side to a higher level on the other. The passageway is provided with a port 9 on the side I nearer the vessel so that, in the event of a surge in the pressure of the gas contained in the vessel, the liquid is depressed until the port is uncovered and the pressure then relieved through the passageway 8 and a port 10 thereby allowing the liquid to return to its normal level and re-cover the port 9; the ports 9, 10 may have their directions reversed in order to overcome a surge in pressure of the air from the outside O of the vessel. Several passageways 8 may be spaced around the sleeve and alternately arranged with the ports 9, 10 facing in opposite directions. In the modification shown in Fig. 3A, two concentric sleeves 19, 20 are carried by a rotatable plate 21 and run in liquid cavities 15, 16, the sleeve 19 having a passageway 22 and ports 23, 24 which, during a pressure surge, function as previously described. The pressurized gas which then escapes through the port 24 acts upon the liquid in the cavity 16 and, if the pressure is high enough, causes the liquid to be depressed until a port 26 in a passageway 25 formed in the sleeve 20 is uncovered, the pressure then being relieved through a port 27. As applied to a nuclear reactor (Fig. 3B, not shown), two rotatable shields are provided with liquid dip seals of the type just described, the liquid in the inner cavities being a mixture of sodium and mercury and that in the outer cavities of mercury only.