Improvements in or relating to chutes, particularly charge chutes for nuclear reactors

摘要

909,862. Servicing reactors. STRACHAN & HENSHAW Ltd. Jan. 8, 1959 [Feb. 4,1958], No. 3698/58. Class 39 (4). A reactor servicing shoot has upper, middle and lower coaxial sections 2, 4, 6 and a movable portion 38 which may be laterally displaced by a link 44 from a position within the section 6 to a position as shown in Fig. 5, for servicing a channel not in alignment with the shoot body, a pair of pulleys 26, 32 being mounted on the section 6 such that when the shoot is inserted through the standpipe 7 the pulleys lie within the shoot, Fig. 2, whereas when the section 6 comes to rest in the reactor the pulleys move through openings in the shoot wall for guiding the hoist rope 58. The shoot section 2 contains a sleeve 10 mounted for sliding movement limited by the engagement of blocks 14 on the sleeve with the section 2 and thus when the shoot is lowered into the reactor by a grab engaging a lip 12 on the sleeve the latter is held at its upper position relatively to the section 2. A pair of links 16 are connected to the sleeve 10 and mounted for longitudinal movement in guides 21 in the section 6, Fig. 6, the links 16 being connected at 17 to cranked links 18 pivoted at 19 to a yoke 20 carrying the pulley 26. The pulley 32 is mounted on arms 34 pivoted at 36 to the movable shoot section 38, blocks 54 on the arms 34 being engaged by blocks 56 on the links 16 whilst the shoot is being lowered. When the weight of the shoot is removed from the sleeve 10 upon the section 6 coming to rest in the reactor the sleeve 10 moves downwardly in the shoot whereby the links 16 also move downwards and the links 18 rotate the yoke 20 about the pivot 22 so that the pulley 26 moves through an opening 28 in the shoot; also, the blocks 56 move clear of the blocks 54, Fig. 6, and permit the pulley 32 to move through an opening 57 under the action of gravity. A fuel element grab may now be lowered into the shoot portion 38 and the link 44 may be actuated as disclosed in Specification 874,222, to move a link 40 pivoted at 42 to the portion 38 whereby the latter is radiused and the arms 34 are held in position by the engagement of rollers 50 with blocks 52.