Abstract: A high pressure cutting arrangement includes two pressurized streams: a liquid stream and a slurry stream. The two streams are independently pressurized, and then combined at pressure. The combined stream is then accelerated through a nozzle to provide a cutting jet.

Abstract: A control system for a high pressure cutting arrangement is disclosed. The cutting arrangement comprises a liquid stream and a slurry stream, the slurry comprising abrasive particles suspended in a fluid. The liquid stream and the slurry stream are both supplied under pressure of about 300 MPa to a cutting tool, with at least a portion of the supplied pressure being converted to kinetic energy in the cutting tool to produce a combined liquid and abrasive stream at high velocity. The cutting tool includes a combining chamber into which both the liquid and slurry streams are introduced, the pressure in an entry region of the combining chamber being determined by the pressure of the liquid stream. The control system acts to actuate or prevent flow of slurry in the slurry stream by activation or de-activation of an energizing means up-stream of the chamber. Pressure in the slurry stream is substantially equal to the pressure in the entry region of the combining chamber whether or not slurry is flowing.

Abstract: A nozzle for a high pressure cutting arrangement is disclosed. The cutting arrangement comprises a liquid stream and a slurry stream, the slurry comprising abrasive particles suspended in a fluid, with both fluids being supplied into the nozzle under pressure. The nozzle has a combining chamber, having an entry region arranged to receive the liquid stream and the slurry stream, such that the pressure in the entry region is determined by the pressure in the liquid stream. The pressure in the entry region acts on the pressure in the slurry stream to regulate the pressure in the slurry stream.

Abstract: A control system for a high pressure cutting arrangement is disclosed. The cutting arrangement comprises a liquid stream and a slurry stream, the slurry comprising abrasive particles suspended in a fluid. The liquid stream and the slurry stream are both supplied under pressure of about 300 MPa to a cutting tool, with at least a portion of the supplied pressure being converted to kinetic energy in the cutting tool to produce a combined liquid and abrasive stream at high velocity. The cutting tool includes a combining chamber into which both the liquid and slurry streams are introduced, the pressure in an entry region of the combining chamber being determined by the pressure of the liquid stream. The control system acts to actuate or prevent flow of slurry in the slurry stream by activation or de-activation of an energising means up-stream of the chamber. Pressure in the slurry stream is substantially equal to the pressure in the entry region of the combining chamber whether or not slurry is flowing.

Abstract: A high pressure cutting arrangement is formed by combining a liquid stream, such as water, and a slurry stream, the slurry comprising abrasive particles suspended in a liquid. Energy is supplied to the liquid stream by a first energising means, such as a constant pressure pump. Energy is supplied to the slurry stream by a second energising means, such as by a piston powered by a constant volume pump. The liquid stream and the slurry stream are combined in a cutting tool, in which the supplied energy is converted to kinetic energy to produce a combined liquid and abrasive stream at high velocity.