| 摘要 |
High kinetic energy water jets (1) are traversed longitudinally of a surface (2) to be treated whilst being oscillated transversely to cover the surface (2). The flow rate (Q) through a nozzle is suitably between 1 and 12 gallons/min (4.55 and 54.6 litre/min) the pressure (P) between 6,000 and 15,000 psi (422 and 1055 Kg/sq.cm) the jet nozzle mean height (z) between 0.25 and 6 inches (0.635 and 15.24 cm) the jet displacement velocity (v) between 100 and 500 ft/min (30.48 and 158.40 metre/min) and the jet nozzles of orifice diameter between 0.5 and 2.0 mm. Apparatus for carrying out the method comprises a vehicle having a carriage (9) mounted for transverse oscillation below a chassis (4), nozzles (1) being supported by the carriage (9) at a predetermined, adjustable, height (2) from the surface (2), means being provided for the supply of high pressure water and to vary the pressure (P), the jet displacement velocity (v), and the rates of traverse of the nozzles (1) both longitudinally and transversely of the surface (2). |
