GB1118814A - Improvements in or relating to liquid grit blasting apparatus - Google Patents

Abstract

1,118,814. Blasting. AJEM LABORATORIES Inc. 3 Sept., 1965 [3 Sept., 1964], No. 37820/65. Heading B3D. Liquid grit blasting apparatus comprises a blast tube through which a liquid grit blast is passed and a deflector plate mounted at a glancing angle to the blast issuing from the blast tube to deflect and direct the blast. Apparatus, Figs. 1 and 2, is partially submerged, e.g. up to liquid level 20, in a reservoir of liquid containing suspended abrasive grit. Driving liquid under high pressure is supplied through a port 22 to a manifold 24 and ejected at high velosity through jet orifices 26 into blast tubes 28 of larger internal diameter, entraining a considerable quantity of the grit-laden liquid. The outer ends of the tubes 28 pass through a plate 32 to ports in the foot 44 of a deflector 30 which directs the abrasive blast against the workpiece 37. The deflector comprises a plate 36 with end members 40 to prevent undue lateral spread of the blast. In a modification, Fig. 5, the deflector plate 36a has welded thereon mounting lugs 46a which are bolted at 45a to uprights 42a on a foot 44a, so that the deflector plate can be removed and replaced by one of different configuration. The foot 44a has ports 48a and tapped holes 50a for bolting the assembly to the blast tube assembly. In a modification, Fig. 8, the deflector plate 36b is corrugated, the troughs being aligned with the ports 48b in the foot 44b. In a modification, Figs. 9 and 10, the apparatus is mounted on a frame 56 and enclosed in a shield 58. The workpiece 37c is carried on a rotating table 62. Short jet tubes 26c convey the driving liquid to the blast tubes 28c from manifolds 24c supplied through pipes 66. Abrasive slurry is collected below the table 62 and returns to a feed hopper 68 from which it is supplied to the blast tubes 28c. Return pipes 70 conduct the slurry from a collector sump to the hopper 68 via a slurry guide baffle 72. A screen 76 below the table 62 prevents recirculation of over-sized particles.