Abstract: A particle separation assembly comprises a vessel provided with an inlet, a first outlet and a second outlet. The assembly is arranged such that the flow rate of fluid through the inlet is greater than the flow rate of fluid through the first outlet such that there is a resultant fluid flow of lighter particles up the vessel and through the second outlet. Flow adjustment means are provided to enable the velocity of this resultant fluid flow to be adjusted, said means comprising a pivotable flap in one example.

Abstract: With reference to FIG. 1 , a blast gun assembly 1 of cylindrical form comprises a plurality of disc-shaped body sections 2, 3, 5 and 10, clamped together in face-to-fact contact. The body sections 2 comprise head sections and carry air/slurry mixture discharge nozzles 14. Each pair of adjacent body sections 2 is separated by a spacer section 3. Sections 2, 3 are formed with internal holes which are aligned to form internal ducts, connected to a slurry inlet 6 and an outlet 7, an air blast 8, and water rinse/air dry supplies 9. Water rinse and/or drying air is discharged from the assembly 1 by nozzles 26.

Abstract: A wet-blast machine (1) with a closed-cycle re-use system (2) incorporates apparatus (3) for conveying loose particulate (abrasive) wet-blast material (4) present in a body of water (5). The apparatus (3) comprises a longitudinally extending trough (6), for containing the water (5) and particulate material (4), a support structure (7) movable in a reciprocating manner within the trough (6), and a row of longitudinally spaced flap members (8) attached to and depending from the support structure (7). When the support structure (7) is reciprocated, wave motions are created in the water (5), which move the loose particulate material (4) in a predetermined direction along the trough (6), namely toward a collection point provided by a chute (10).

Abstract: Wet blast apparatus 1 is provided with a sump 2 for collecting liquid and abrasive particles after use, a duct 40 for conducting the collected material to a three-stage weir system 4 whereby the particles are separated out. The apparatus is further provided with a fluid flow control valve 3 operable to control the flow of collected material to the separating system 4. An adjustable timer 25 is provided for delaying the flow of collected material to the separating system 4. The control valve 3 comprises a valve member 6 cooperable with a valve seat 7, the valve member 6 being expansible whereby it can be enlarged so as to coact with the valve seat 7. The valve member 6 is of hollow, inflatable form, comprising a flexible membrane 10, clamped between a plate 11 and a ring 12. An actuating chamber 20 is defined by the plate 11 and the membrane 10. Pressurized air is admitted to, and exhausted from, the chamber 20 by way of a control valve 21 disposed in an air line 22.