Fluid jet cutting and shaping system

Abstract

Fluid jet cutting system with nozzle assembly having a monolithic main body with a central fluid passageway with fixed diameter intermediate fluid jet passageway with orifice component at un upper end. The upper end of a modified focus tube is positioned directly below the outlet of the fluid jet passageway such that the enlarged opening at the upper end of the focus tube forms the mixing chamber. This avoids the high cost of mixing chamber wear inserts. The enlarged upper end opening has a diameter equal to or larger than a circumferential ring contacting the external most portion of the outlet of each of the preferably 3 or 4 abrasive ports spaced about the main body. The focus tube with mixing chamber enlargement avoids efficiency degrading abrasive contact with wall surfaces of the nozzle assembly. The abrasive ports extend from an upper, sloped surface of the main body to the abrasive ports outlet with the central axis of the abrasive ports forming an acute angle of less than 15 degrees. This angle minimization results in less efficiency degrading horizontal velocity components in the abrasive feed through the nozzle assembly, and also reduces surface wear contact in the main body since the abrasive ports dump the abrasive more along the central axis of the fluid filled fluid passageway and less into the side walls of the nozzle assembly and more into the fluid stream directly in a mixing region provided by the enlarged focus tube mixing chamber. The mixing chamber is preferably in the form of a deepened V configuration with a non-converging, uppermost section (e.g., a cylindrical section) having the largest diameter and a lower positioned converging section spaced below. The low wear features allows for the focus tube and main body to be formed of a material that is relatively less expensive than the high abrasion resistant material wear inserts.