GB663604A - Sand blasting device - Google Patents

Abstract

663,604. Sand-blast. KRANS, H. VAN DER. Sept. 20, 1949 [Sept. 30, 1948], No. 24156/49. Class 60 The invention relates to sand blasting devices of the kind in which dry sand is discharged under pressure from a nozzle in the form of a jet enclosed within a tubular stream of water, the water serving to wet the sand after the latter has impinged against the surface of an object to be cleaned and thereby prevent the sand particles or dust from remaining in the air. A device of this kind in which the nozzle is located within a casing to which are connected supply conduits for the sand and water respectively, is characterised in that said nozzle is secured to a tubular conical member by the casing, the latter being screwed to one end of said member and having an internal flange engaged with the nozzle, the other end of said conical member being provided with means for connecting it to the sand supply conduit. The device consists of a conical body 1 to which a pipe 2 is connected, the pipe having a collar 16 secured thereto by fastening means 3, 4, and the enlarged inner end 5 of the body 1 being internally screw-threaded to receive the threaded end of the collar 16. The central body 1 discharges into a nozzle 7 provided with a wear-resistant lining 6. A tubular casing 8 mounted on the outer end of the central body 1 surrounds the nozzle 7, the inner diameter of the casing being greater than the outer diameter of the nozzle 7. The casing 8, which terminates in a mouth 9 beyond the outer end of the nozzle 7, is formed with a connection 11 communicating with a water supply and having a bore 14 leading to the interior of the casing. The inner end of the casing 8 is internally threaded at 13 to receive a threaded part 12 of the body 1. The nozzle 7 is seated within the outer end of the body and is held in position by the engagement of an internal flange 8a of the casing 8 with an external flange 7a on the nozzle. That portion of the body 1 extending between the conduit 2 and the nozzle 7 is provided with a rubber lining 15 having a conical bore, the larger diameter end of this bore being equal or substantially equal to the internal diameter of the conduit 2 and the smaller diameter end of the bore being about equal to the internal diameter of the adjacent end of the nozzle and communicating directly with the nozzle. The casing 8 is tapered so that the cross-sectional area of the space 10 between the nozzle and the casing gradually decreases towards its outer end. If the surrounding layer of water is not required, e.g. when sand blasting ships in the vicinity of the chocks, the casing 8 is replaced by a flanged nut engaging the flange 7a of the nozzle 7.