Method and apparatus for jet-assisted drilling or cutting
View Patent ↗An abrasive cutting or drilling system, apparatus and method, which includes an upstream supercritical fluid and/or liquid carrier fluid, abrasive particles, a nozzle and a gaseous or low-density supercritical fluid exhaust abrasive stream. The nozzle includes a throat section and, optionally, a converging inlet section, a divergent discharge section, and a feed section.
1. A method of cutting or drilling comprising the steps of:
providing an abrasive-laden primarily liquid or high density supercritical fluid under predetermined pressure and temperature, wherein said abrasive-laden primarily liquid or high density supercritical fluid comprises a suspension of said abrasive particles in said abrasive-laden primarily liquid or high density supercritical fluid;
delivering said abrasive-laden primarily liquid or high density supercritical fluid to a nozzle;
increasing velocity of said abrasive-laden primarily liquid or high density supercritical fluid as it passes through a flow-restriction in said nozzle;
beginning expansion of said primarily liquid or high density supercritical fluid into its gaseous or low-density state as it passes through said nozzle;
transferring kinetic energy from said expanding fluid to said abrasive particles to accelerate velocity of said particles; and
discharging a gas-carrying or low-density supercritical-fluid-carrying abrasive jet stream containing abrasive particles from said nozzle.
2. The method of claim 1 wherein said primarily liquid or high density supercritical fluid is chosen from the group consisting of carbon dioxide, water, nitrogen, propane, butane, freon, and methane.
3. The method of claim 1 including the additional step of introducing an additive to the primarily liquid or high density supercritical fluid and abrasives prior to delivering to the nozzle.
4. The method of claim 3 wherein said additive is a foaming agent.
5. The method of claim 3 wherein said additive is a surfactant.
6. The method of claim 3 wherein said additive is a polymer.
7. The method claim 3 wherein said additive is water.
8. The method of claim 3 including the additional preliminary steps of making a batch of abrasive slurry in a tank and discharging said slurry through a delivery line then adding primarily liquid or high density supercritical fluid to the slurry.
9. The method of claim 1 wherein the abrasive jet stream is directed against a target substance that may comprise any material on the Earth, other planet, or body in space.
10. The method of claim 1 wherein said step of delivering said abrasive-laden supercritical fluid/liquid to a nozzle and passing through said nozzle includes delivering said abrasive-laden supercritical fluid/liquid to multiple nozzles arrayed on a single head and passing through said multiple nozzles.
11. The method of claim 10 wherein said single head rotates about an axis.
12. The method of claim 1 including an additional preliminary step of preparing an abrasive particle slurry in a liquid before adding it to a supercritical fluid.
13. The method of claim 1 including the additional step of controlling rate of expanding said primarily liquid or high density supercritical fluid by passing through a diverging section of said nozzle.
14. The method of claim 1 wherein the flow is directed first through a converging section of the nozzle, followed by a straight bore section, followed by a diverging section of the nozzle.
15. A method of cutting or drilling comprising the steps of:
providing an abrasive-laden primarily liquid or high density fluid under predetermined pressure and temperature, wherein said abrasive-laden fluid comprises a suspension of said abrasive particles in said fluid;
delivering said primarily liquid or high density abrasive-laden fluid to a nozzle;
increasing velocity of said abrasive-laden fluid as it passes through a flow-restriction in said nozzle;
expanding said fluid into its gaseous or low-density state as it passes through said nozzle;
transferring kinetic energy from said expanding fluid to said abrasive particles to accelerate velocity of said particles; and
discharging a gas-carrying or low-density fluid-carrying abrasive jet stream containing abrasive particles from said nozzle.
16. The method of claim 15 wherein the flow is directed first through a converging section of the nozzle, followed by a straight bore section, followed by a diverging section of the nozzle.
17. The method of claim 1 including the additional preliminary step of introducing an additive to said abrasive-laden primarily liquid or high density supercritical fluid.