GB1269814A - Abrasive blast system - Google Patents

Abstract

1,269,814. Filtering and settling system. A. H. EPPLER. 14 April, 1969, No. 18885/69. Heading BID. [Also in Division B3] Slurry 12 in a sump 14 at the bottom of a blast chamber 6 is supplied by a pump 16 to blast nozzles 8; preferably air under pressure is supplied to the nozzle through a pipe 22 to accelerate the slury towards the work 20 which is supported on a turntable or on rods 26. A fan 28 withdraws vapour from the blast chamber 6 through a baffle 30. A rinse chamber 32 may be a more or less separate chamber inside or outside the blast chamber 6 or merely a designated area of the blast chamber; it is preferably partially segregated by a low partition 34 to withold rinse liquid, e.g. water, from the sump. When the work reaches the rinse chamber, it is acted on by high velocity jets of clear water from nozzle 36. Rinse water with entrained abrasive is collected in a float chamber 40. The float chamber may be attached to the sump 14 or separate; in either case, means, e.g. pipe 42, is provided for discharging rinse water with entrained abrasive into the float chamber and other means, e.g. pipe 44 or port 46, is provided for connecting the float chamber 40 and the sump 14 at water level, this level being maintained by a float 48 regulating a valve 50 controlling admission of make-up water from a pipe 52. A baffle 54 prevents surges to and from the sump 14. A pipe 56 leads from the chamber 40 to a pump 58 which discharges tangentially into a centrifugal separator 60. Re-useable abrasive is discharged through the lower end 64 of the separator 60 into the sump. Water and entrained fines are discharged from the upper end and pass through a pipe 66 to a settling chamber 68; any excess water returns through a pipe 70 to the chamber 40. Further settling chambers 72, 74 and replaceable filters 76, 78 are provided. A pipe 80 connects the final chamber to a pump 38 supplying the rinsing nozzles 36, so that the substantially clear rinse water is re-used. Material settling out in chambers 68, 72, 74 is drawn off through drain parts 88 or allowed to accumulate and removed from time to time mechanically.