GB1367390A - Shot blasting device - Google Patents

Abstract

1367390 Blasting G SHIGYO 11 April 1972 [10 Dec 1971] 16579/72 Heading B3D A device for blasting the surface C of a ship's hull or a tank comprises a frame 40<SP>1</SP>, an opening 12 from which a blast of shot can be ejected to impinge on and clean the surface, blast means 1 for causing the blast, recovery means whereby shot which has impinged on the surface can be separated from detritus from the surface and returned to an inlet 8 of the blast means, and means whereby the device may be held in close engagement with the surface to be shot blasted. The device may be supported by a rope 42 and hook 41 from the jib of a crane movable along a dock wall or by apparatus movable along a rail on the top of the tank. The blast means consists of a centrifugal wheel having blades 3 which is supported by a shaft 6 mounted in a bearing block 5 and driven by a motor 7, the wheel being disposed in a casing 2 supplied with shot from a hopper 8 and shoot 9. The casing has an opening 11 leading to a slot 12 through which the blast impinges on the surface C. A passage extends downwardly from the slot to a passage 21 for receiving spano shot and detritus, the passage also communicating with a pair of openings 14, 15 below the opening 12 for collecting shot and detritus which passes a seal around the opening. A dust collection rectangular slot 13, 16, 17, 18 surrounds the openings 12, 14, 15. The spent shot falls through passage 21 into a conveyer comprising a circular runner 25 of U-shaped cross-section and formed with blades 28, the runner being disposed in a similarly-shaped housing 22 and supported by rollers 26, one of which is driven by a motor 27. The conveyer transports the shot from the passage 21 to the hopper 8. Alternatively, a bucket, case or screw conveyer may be used. Dust and other detritus passing through passage 21 is sucked through an aperture 70 into a passage 30, which is also connected to the dust collecting slot 13, 16, 17, 18, and to a rotary blower 29, in turn, connected to a cyclone wire mesh 31 where scale and paint chips fall to a container, the air passing through an exhaust pipe 34. A rust removing device 36 is mounted above the opening 12 and consists of a double row of bundles of hard parallel wires 39 which are reciprocated by an air supply which also passes between the needles. The means for holding the device in close engagement with the surface may consist of suction pads or, as described, magnets 53 which are resiliently mounted on plates 52 carried by a common plate 48. The magnets are held slightly spaced from the surface by ball casters 65 or roller chains 45 so that the device can move horizontally and vertically over the surface. The chains 45 are mounted on sprocket wheels 44 driven by a motor 56.