GB889709A - Improvements in or relating to mechanical handling equipment including a carriage and a grab - Google Patents

Abstract

889,709. Vehicles equipped with lever-arm machines for loading. BABCOCK & WILCOX Ltd. Sept. 23, 1960 [Sept. 23, 1959], No. 32392/59. Class 78 (4). [Also in Group XL (a)] Debris which has fallen into a coolant duct 2 entering the bottom of the pressure vessel of a gas-cooled nuclear reactor is removed by a remotely-controlled carriage 12 which, after depressurization of the reactor, is advanced along a track 10 through an axuiliary duct 4 and into the duct 2. The carriage 12 is controlled from a position behind a shielding wall 50 in a chamber 7 adjacent a biological shield wall 6 and before the carriage is brought into the chamber a pair of plugs (Figs. 2, 6, not shown) are extracted from the duct 4 by a winch 51 and pulley 52 and deposited by a crane 24 in a pair of holes 40, 42. The carriage 12 (Figs. 7, 9), is supported on the track 10 by wheels 98, 100 and has a turret 110 supporting a jib 112 and a television camera 114. A rotatable grab head 118 on the jib carries a jaw 120 and the carriage 12 carries lights 116. Extending lengthwise along the carriage is a removable canister 92 and within the canister is a trough 134 which may be projected for. wardly relatively to the canister to the position shown in chain-lines in Fig. 7 by a reciprocable rack 136 mounted in the carriage. The rack is detachably connected at its forward end by a catch 148 to the trough 134 and has rollers 146 engaging the track 10. The movements of the carriage and the above-mentioned movable members and devices mounted thereon are controlled by electric motors the cables of which are wound on to a pay-off drum 70. In use, the carriage 12 with its jib 112 in the retracted position, shown in chain-lines in Fig. 7, is advanced through the duct 4 and when in the duct 2 the jib is rotated to project forwardly. The camera 114 is moved to keep the debris in view and the carriage is stopped, the jib is lowered and the jaw 120 operated to grasp the debris which is then raised. The trough 134 is projected beneath the jaw and the debris deposited therein, the trough then being retracted. This procedure is repeated until all the debris is in the trough. The carriage 12 is returned to the chamber 7 where the canister 92 is lifted from the carriage into an upright position, shown in chain-lines in Fig. 1, and dropped into a coffin 74, the coffin being subsequently removed to a cooling pond. In falling into the coffin the canister passes through braking means comprising a rubber ring. The means for lifting the canister into the upright position are described with reference to Fig. 10 (not shown). In a modification (Figs. 12-17, not shown), the canister and trough are omitted and the carriage 12 carries a vacuum cleaner for the removal of dust or small particles from the duct 2, the nozzle of the vacuum cleaner being held by the jaw 120.