Apparatus and process for employing synergistic destructive powers of a water stream and a laser beam

• US 5,356,081 A
• Filed: 02/24/1993
• Issued: 10/18/1994
• Est. Priority Date: 02/24/1993
• Status: Expired due to Fees

• Current Assignee: Redstone Australia Mining Pty Limited
• Original Assignee: Electric Power Research Institute Incorporated
• Inventors: Sellar, John G.
• Primary Examiner(s): Watts, Douglas D.
• Application Number:
  US08/021,911
• Time in Patent Office: 601 Days
• Field of Search: 241/1, 241/17, 241/33, 241/65, 299/14, 299/16, 219/121.62, 219/121.69, 219/121.71, 219/121.72, 219/121.84, 219/121.85
• US Class Current: 241/1
• CPC Class Codes: B23K 2103/30 Organic material
• CPC Class Codes: B23K 2103/50 Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26
• CPC Class Codes: B23K 26/032 using optical means
• CPC Class Codes: B23K 26/0648 comprising lenses
• CPC Class Codes: B23K 26/0665 by beam condensation on the workpiece, e.g. for focusing
• CPC Class Codes: B23K 26/1224 in vacuum
• CPC Class Codes: B23K 26/142 for the removal of by-products
• CPC Class Codes: B23K 26/146 the fluid stream containing a liquid
• CPC Class Codes: B23K 26/40 taking account of the properties of the material involved
• CPC Class Codes: B28D 1/221 by thermic methods
• CPC Class Codes: E21C 25/60 Slitting by jets of water or other liquid picks with arrangement of fluid-spraying nozzles E21C35/187; distribution of spraying fluids in rotating cutter-heads E21C35/23

Abstract

The present invention is a novel apparatus for excavating a mass, such as a rock. The present invention directs a high velocity fluid stream onto a mass and simultaneously directs a pulsing laser beam onto the same mass. The laser beam vaporizes material and the fluid confines the vaporized material causing shock waves to enter the rock. The confined shock waves impart greater force than non-confined shock waves and this greater force fractures the mass. The fluid stream also washes loose particles from the mass to provide a new excavation surface.

Claims

1. An apparatus for fracturing a mass of material, the apparatus comprising:

means for applying a fluid to said mass comprising a conduit having a fluid inlet, a fluid flow chamber, and a fluid outlet;

said conduit for converting fluid from a pressurized fluid source into a fluid stream and for aiming said stream onto a particular location on said mass;

a fracturing laser beam for fracturing said mass; and

a laser beam aiming means for aiming said fracturing laser beam onto said particular location;

wherein said means for applying said fluid and said laser beam aiming means are disposed such that said fracturing laser beam is surrounded by an envelope formed by said fluid stream;

such that said fracturing laser beam and said fluid combine at said particular location to achieve a fracture rate for said mass substantially higher than a fracture rate of either said fracturing laser beam or said fluid acting on said mass alone.

2. The apparatus of claim 1 in which said flow chamber further comprises a flow chamber window which is transparent to said fracturing laser beam and which is disposed within said conduit to permit said fracturing laser beam to pass through said conduit said flow chamber window, said flow chamber, and said water outlet, respectively.

3. The apparatus of claim 2 in which said fracturing laser beam aiming means further comprises a one-way mirror,

said one-way mirror being disposed between said flow chamber and said laser beam aiming means, said one-way mirror intersecting said fracturing laser beam,

said one-way mirror being transparent to said fracturing laser beam when said fracturing laser beam travels in a direction of said mass but said one-way mirror being reflective to radiation from said fracturing laser beam when said radiation travels in a direction from said mass into said flow chamber.

4. The apparatus of claim 3 further comprising a selective mirror,

said selective mirror and said one-way mirror being disposed so that said fracturing laser beam when traveling through said water outlet into said flow chamber is reflected by said one-way mirror onto said selective mirror;

said selective mirror being transparent to the wavelength of said fracturing laser beam to permit said fracturing laser beam to harmlessly pass through said selective mirror such that said fracturing laser beam may be dissipated.

5. The apparatus of claim 4 wherein said selective mirror and said one-way mirror are disposed so that said monitoring laser beam when traveling through said water outlet into said flow chamber is reflected by said one-way mirror onto said selective mirror;

said selective mirror reflecting said monitoring laser beam onto a connector where said monitoring laser beam is sensed by a receiver.

6. The apparatus of claim 3 in which said fracturing laser beam is pulsed at a resonant frequency of said mass.

7. The apparatus of claim 3 further comprising a monitoring laser beam for monitoring the resonant frequency of said mass.

8. The apparatus of claim 7 wherein said fracturing laser beam is pulsed at a resonant frequency of said mass.

9. The apparatus of claim 7 further comprising a selective mirror,

said selective mirror and said one-way mirror being disposed so that said fracturing laser beam when traveling through said water outlet into said flow chamber is reflected by said one-way mirror onto said selective mirror;

said selective mirror being transparent to the wavelength of said fracturing laser beam to permit said fracturing laser beam to harmlessly pass through said selective mirror such that said fracturing laser beam may be dissipated.

10. The apparatus of claim 9 wherein said selective mirror and said one-way mirror are disposed so that said monitoring laser beam when traveling through said water outlet into said flow chamber is reflected by said one-way mirror onto said selective mirror;

said selective mirror reflecting said monitoring laser beam onto a connector where said monitoring laser beam is sensed by a receiver.

11. The apparatus of claim 1 further comprising means for removing air that is trapped within said flow chamber from said flow chamber.

12. An apparatus for fracturing a mass of material, the apparatus comprising:

a pulsing laser beam having a wavelength alpha;

a monitoring laser beam having a wavelength beta;

a conduit for converting water from a pressurized water source into a stream;

said conduit having an inlet, a flow chamber, a nozzle, an outlet, an air bleed valve, and a flow chamber window;

said conduit being adapted to permit said pressurized water to flow through said conduit to said mass by way of said inlet, said flow chamber, said nozzle, and said outlet, respectively;

said pressurized water forming a stream upon its exit from said outlet;

said air bleed valve being adapted to permit removal of air from said flow chamber;

said flow chamber window being transparent to laser radiation having wavelengths alpha and beta, said conduit having a beam path adapted to permit said pulsing laser beam and said monitoring laser beam to pass through said conduit to said mass by way of said flow chamber window, said flow chamber, said outlet, respectively;

said beam path being longitudinally enveloped by a cylinder formed by said stream;

a beam aiming means for aiming said monitoring laser beam and said pulsing beam through said conduit to said mass by way of said beam path;

said beam aiming means having a lens chamber for housing a lens system;

said lens system for focusing said pulsing beam onto said mass;

said beam aiming means having a mirror chamber housing a mirror system for aiming said monitoring laser beam through said beam path;

said lens system comprising a biconvex lens and a biconcave lens, said biconvex lens and biconcave lens disposed on an optical axis passing through said beam path;

said biconvex lens and biconcave lens being adjustable to provide selectable focal points;

said mirror system comprising a one-way mirror and a selective mirror;

said one-way mirror intersecting said optical axis and said one-way mirror being located between said lens system and said flow chamber window;

said one-way mirror having a reflective surface that is optically reflective to wavelengths alpha and beta and a transparent surface that is optically transparent to wavelength alpha;

said one-way mirror disposed to permit said pulsing beam to pass through said one-way mirror and then through said beam path;

said selective mirror having a surface reflective to wavelength beta but transparent to wavelength alpha;

said one-way mirror and said selective mirror disposed to permit said selective mirror to reflect said monitoring laser beam onto said one-way mirror and to permit said one-way mirror to then reflect said monitoring laser beam through said beam path;

said one-way mirror and said selective mirror being further disposed so that light of wavelengths alpha and beta traveling into said conduit by way of said inlet is reflected by said one-way mirror onto said selective mirror;

which selective mirror further reflects said light of wavelength beta onto said second fiber optic connector where it is sensed by a receiver;

which selective mirror permits said reflected light of wavelength alpha to pass through said selective mirror allowing said reflected light of wavelength alpha to be dissipated;

such that said pulsing beam and said stream combine to achieve a fracture rate for said mass substantially higher than a fracture rate of either said pulsing beam or said stream acting alone.

13. A process for using a fracturing laser beam, and a fluid to fracture a mass of material, the process comprising the steps of:

applying said fluid to said mass;

wherein said step of applying said fluid to said mass comprises the steps of converting said fluid to a fluid stream and aiming said fluid stream onto a particular location on said mass;

aiming said fracturing laser beam onto said particular location; and

aiming a monitoring laser beam onto said mass to monitor a resonant frequency of said mass such that said fracturing laser beam may be adjusted to match said resonant frequency;

such that said fracturing laser beam and said fluid combine at said particular location to achieve a fracture rate for said mass substantially higher than a fracture rate of either said fracturing laser beam or said fluid acting alone.

14. The process of claim 13 further comprising a step of adjusting said fracturing laser beam to match said resonant frequency.

15. The process of claim 14 wherein said fluid is a liquid.

16. The process of claim 15 wherein said liquid is water.

17. The process of claim 13 wherein said fluid is a liquid.

18. The process of claim 17 wherein said fluid is water.

19. The process of claim 13 wherein said step of applying said fluid stream to said mass is performed by surrounding said fracturing laser beam by am envelope formed by said fluid stream.

20. The process of claim 19 wherein said envelope is a cylindrical fluid envelope.