GB1040431A - Improvements in or relating to metal framed windows, more particularly for radio-active enclosures - Google Patents

Abstract

1,040,431. Viewing equipment for radioactive environment. SAINT - GOBAIN TECHNIQUES NOUVELLS. March 20, 1963 [March 20, 1962; Jan. 28, 1963], No. 11108/63. Heading B4Q. [Also in Division E1] An observation window for a radio-active enclosure, the window comprising one or more glass slabs carried in a metal framework mounted in an opening in the enclosure wall, wherein fluid-tightness between the glass slab or slabs and the metal framework is obtained by joints formed of a material which was in a plastic state at the time of its application but has subsequently been polymerized in situ, said material remaining resilient after polymerization and adhering well both to the glass and to the metal. A preferred material is " Thiokol ' (Registered Trade Mark). As shown, the metal wall 1 of the enclosure has an opening in which is fitted a window comprising glass slabs 2, 3, 4 mounted in a metal framework 5, 5a, 5b. At the " hot " side of the opening the wall has an angle member 6 fixed thereto, a frame 8 being secured to the wall within the enclosure. A glass plate 10 is sealed between the member 6 and frame 8 by a resilient joint 11, a supplementary joint 12 resistant to nitric acid being provided. The framework 5, 5a, 5b rests on ribs 13, whereby a space 14 is formed which is filled with a dehydrating agent 15, e.g. silica gel, and with lead 16. At the " cold " side of the window the space 14 is sealed by a joint 17. The metal framework 5, 5a, 5b includes a frame 18, lead angle pieces 20, 21, lead spacers 22, 22a, 24 and a frame 25, a glass plate 23 being sealed by a joint 27. A liquid, e.g. paraffin, covers the slabs 3, 4 and fills the space 28 between slabs 2, 3, the liquid being confined by the glass plate 23 and joint 27 and by the slab 2 and a joint 29. Lead packing 16a fills the space between the joint 29 and the angle piece 20. In a modification (Fig. 2, not shown), the joint 29 surrounds the slab 3 and hence the space 28 is not filled with the liquid. The entire window may be removed from the opening by cutting the joint 17, the enclosure remaining sealed by the glass plate 10. The joints 11, 17, 27 and 29 are of Thiokol, the material in a viscous state being applied by a syringe and being polymerized in situ. To facilitate dismantling of the window the joints 11, 17, 27 and 29 include wires 42, 43, 44, 40, the wires extending throughout the length of the joints and having their free ends accessible. If piano wire is used, the joints may be cut by simple mechanical pulling on the wire ends; alternatively, the cutting may be made easier by using wire of substantial electrical resistance and passing a current therethrough to heat the joint material.