Rapid material analysis using LIBS spectroscopy

Patent metadata

Field	Value
Publication number	US-10088425-B2
Application number	US-201515321143-A
Country	US
Kind code	B2
Filing date	Jun 19, 2015
Priority date	Jun 23, 2014
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

Abstract

A LIBS measurement system is described herein that provides an orifice, aperture or opening in a substantially V-shaped chute or sleeve that allows access to the material to be analyzed from the underside of the chute. The laser beam is aimed through the hole and return light (signal) is collected through the hole by a photodetector assembly. A diverter device, which is located at an output end of the chute, diverts certain particles away from the chute upon receipt of an actuation signal.

First claim

We claim:

1. A bulk sampling and laser-targeting system to provide for material identification of a bulk stream of material comprising:
a flow chute having a feeder end and an output end, the output end adapted to extend at an angle away from the feeder end such that the flow chute is at an incline and the bulk stream of material flows along the flow chute gravitationally, the flow chute having a substantially concave-shaped, open configuration along a length of the flow chute, the flow chute including an aperture disposed at a point of maximum concavity of the flow chute that is distal to the feeder end;
a LIBS laser system disposed adjacent the aperture and configured to direct a pulsed laser beam through the aperture, the aperture having a defined x, y, z location with respect to the laser beam, and into a material flowing through the flow chute, the aperture having a size sufficient to permit the laser beam to pass through to individual particles of the flowing material and to permit radiation from the individual particles to transmit back through the aperture; and
a radiation detection device disposed adjacent the aperture and adapted to collect the radiation emitted from the individual particles of material, wherein the radiation detection device is communicatively coupled to the LIBS laser system that includes a spectrometer and a controller, the spectrometer configured to identify a composition of the individual particles flowing in the chute.

2. The system of claim 1 further comprising:
at least one particle diverter device disposed adjacent the output end of the chute and adapted to divert the individual particle towards a collection system, wherein the at least one particle diverter device is communicatively coupled to the controller and is adapted to actuate upon receipt of a signal from the controller.

3. The system of claim 2 wherein the at least one particle diverter includes a diverter device adapted to emit a burst of pressurized air when actuated at one or more individual particles of material so as to divert the individual particle towards the collection system.

4. The system of claim 1 wherein the radiation detection device includes a pierced mirror assembly configured to allow the laser beam to pass from a back side of the mirror assembly and through a hole of the mirror, while a front side of the mirror assembly is configured to substantially reflect the return light out of the laser beam path and onto a radiation detector optics.

5. The system of claim 2 wherein the collection system comprises a first collection bin for receiving the diverted particles.

6. The system of claim 5 wherein the collection system comprises a second collection bin for receiving particles traveling on a natural path from the output end of the chute.

7. The system of claim 1 further comprising a cleaning assembly configured to maintain optics of the LIBS and the radiation detection system substantially dust-free.

8. The system of claim 1 further comprising a transparent or translucent member disposed over the aperture.

9. The system of claim 1 wherein a repetition rate of the LIBS laser beam is a function of the speed of material flow along the flow chute and wherein the speed of material flow along the flow chute is a function of the angle of the chute.

10. The system of claim 2 wherein the at least one diverter device includes a physical diverter selected from the group consisting of a wall, a movable paddle or lever, and a controllable trap door at the floor of the flow chute.

11. The system of claim 1 , wherein the concave-shaped flow chute has a substantially V-shaped configuration.

12. The system of claim 1 , wherein the concave-shape of the flow chute is selected from the group consisting of a U-shape with perpendicular sides; U-shaped with flat bottom side; a U-shape with sides angled outward and flat bottom; and a U-shape with sides angled outward and a curved bottom.

13. The system of claim 12 , further comprising a vibration mechanism operatively coupled to the flow chute to promote downward flow of the stream of material.

14. The system of claim 1 , wherein the flow chute comprises a ramp with a vibration mechanism operatively coupled thereto to promote downward flow of the stream of material.

15. A bulk sampling and laser-targeting system to provide for material identification of a bulk stream of material comprising:
a flow chute having a feeder end and an output end, the output end adapted to extend at an angle away from the feeder end such that the flow chute is at an incline and the bulk stream of material flows along the flow chute gravitationally, the flow chute having a substantially v-shaped, open configuration along a length of the flow chute, the flow chute including an aperture disposed at a point of maximum concavity of the flow chute that is distal to the feeder end;
a LIBS laser system disposed adjacent the aperture and configured to direct a pulsed laser beam through the aperture, the aperture having a defined x, y, z location with respect to the laser beam, and into a material flowing through the flow chute, the aperture having a size sufficient to permit the laser beam to pass through to individual particles of the flowing material and to permit radiation from the individual particles to transmit back through the aperture; and
a radiation detection device disposed adjacent the aperture and adapted to collect the radiation emitted from the individual particles of material, wherein the radiation detection device is communicatively coupled to the LIBS laser system that includes a spectrometer and a controller, the spectrometer configured to identify a composition of the individual particles flowing in the chute from radiation received through a pierced mirror assembly configured to allow the laser beam to pass from a back side of the mirror assembly and through a hole of the mirror, while a front side of the mirror assembly is configured to substantially reflect the return light out of the laser beam path and onto a radiation detector optics of the radiation detection device.

16. The system of claim 15 further comprising at least one particle diverter device disposed adjacent the output end of the chute and adapted to divert the individual particle towards a collection system, wherein the at least one particle diverter device is communicatively coupled to the controller and is adapted to actuate upon receipt of a signal from the controller.

17. The system of claim 16 wherein the at least one particle diverter includes a diverter device adapted to emit a burst of pressurized air when actuated at one or more individual particles of material so as to divert the individual particle towards the collection system.

18. The system of claim 16 wherein the at least one diverter device includes a physical diverter selected from the group consisting of a wall, a movable paddle or lever, and a controllable trap door at the floor of the flow chute.

19. A method of bulk sampling and laser-targeting of a bulk stream of material comprising the steps of:
providing an angled flow chute having a feeder end and an output end adapted to extend at an angle away from the feeder end such that the flow chute is at an incline and the bulk stream of material flows along the flow chute gravitationally, the flow chute having a substantially v-shaped, open configuration along a length of the flow chute, the flow chute including an aperture or orifice disposed at a nadir or trough of the flow chute that is distal to the feeder end;
directing a

Assignees

• Tsi Inc

Inventors

• Buckley Steven G
• Niccum Darrick L

Classifications

• G01N21/718 Primary

  Laser microanalysis, i.e. with formation of sample plasma · CPC title

• G01J3/443

  Emission spectrometry · CPC title

• B07C5/365

  using a single separation means · CPC title

• B07C2501/0018

  Sorting the articles during free fall · CPC title

• B07C5/3425 Primary

  of granular material, e.g. ore particles, grain (investigation moving fluids or granular solids using optical means G01N21/85) · CPC title