Abstract: The present invention provides a nozzle for high-pressure abrasive jet cutting systems that is particularly well-suited for fine-kerf cutting (e.g., 0.050 to 0.45 mm) using very fine abrasive particles (e.g., average particle size less than about 250 microns). The nozzle has a nozzle body defining an elongated channel extending along an axis. The elongated channel has a mixing stage and a focusing stage. The focusing stage has a focusing portion terminating in an outlet orifice for producing a high-pressure jet. The mixing stage has a sidewall defining a port in fluid communication with the elongated channel for admitting a low-pressure flow of a slurry comprising abrasive particles suspended in a fluid. The sidewall of the mixing stage is configured to have a relieved portion extending radially inwardly from the port toward the focusing stage. In certain embodiments, the taper is continuous from the port to the focusing stage.

Abstract: A method of making a filter or screen can include directed a high pressure cutting jet against a hard material at a plurality of positions to be cut that are separated by a portion of the material that is to remain uncut. Prior to moving from a first position to a second position, the abrasive can be replaced with a liquid or gaseous interference medium in such a way that reduces an energy density of the cutting jet from an energy density sufficient to remove or cut the material to an energy density insufficient to remove or cut the material. Once moved from the first position to the second position, the interference medium can be replaced with the abrasive in such a way that increases the energy density of the cutting jet from an energy density insufficient to remove the material to an energy density sufficient to remove the material.

Abstract: A method to interrupt the operation of a cutting jet exiting a cutting head having a nozzle is designed such that the cutting jet is laterally supplied with interfering means as needed following the nozzle exit which reduces the energy density of the cutting jet.

Abstract: A method of making a filter or screen can include directed a high pressure cutting jet against a hard material at a plurality of positions to be cut that are separated by a portion of the material that is to remain uncut. Prior to moving from a first position to a second position, the abrasive can be replaced with a liquid or gaseous interference medium in such a way that reduces an energy density of the cutting jet from an energy density sufficient to remove or cut the material to an energy density insufficient to remove or cut the material. Once moved from the first position to the second position, the interference medium can be replaced with the abrasive in such a way that increases the energy density of the cutting jet from an energy density insufficient to remove the material to an energy density sufficient to remove the material.

Abstract: A method to interrupt the operation of a cutting jet exiting a cutting head having a nozzle is designed such that the cutting jet is laterally supplied with interfering means as needed following the nozzle exit which reduces the energy density of the cutting jet.