Method and apparatus for forming a high velocity liquid abrasive jet

DETAILED DESCRIPTION The invention provides a method and apparatus for producing high velocity, abrasive loaded, coherent streams of liquid.
The invention maximizes abrasive particle exit velocity and reduces nozzle wear to provide a long service life.
The method of the invention first forms a stream of high velocity liquid.
The stream is directed through a chamber where abrasive particles of low velocity and random direction are added.
Air flow in the chamber directs the particles into the entry of the mixing tube where they randomly impact the high velocity water jet.
The result is a mixture of high velocity liquid and particles of abrasive having random direction and velocity.
This mixture then continues into a reorientation zone where the particles of abrasive are allowed to orient their direction to that of the liquid.
This results in a stream of liquid having abrasive particles entraped at its core region.
This stream is allowed to continue motion in a nozzle until the particles are accelerated to a velocity approaching that of the liquid.
Finally, the stream of liquid and rapidly moving particles exit the nozzle.
The apparatus of the invention includes a nozzle having zones of curvature and profile necessary to accomplish the method.
The entry zone is a converging conical section that may be produced by the action of the particles themselves.
A change in outline forms the beginning of the reorientation zone.
An accelerator zone follows which may be a straight section.