Scrap detector
First Claim
1. A process of analyzing metal particles for their chemical composition by laser-induced breakdown spectroscopy and of generating a sorting signal, said process comprising:
- (1) irradiating the surface of a metal particle using a cleaning pulse from a first UV-gas-laser;
(2) removing the plasma produced by the cleaning pulse using an air jet of at least 10 m/sec.;
(b
3) producing a plasma by directing an analysis pulse from the first UV-gas-laser or another UV-gas-laser to the cleaned surface;
(b
4) filtering predetermined, selectable wavelengths from the total radiation of the plasma produced by the analysis pulse;
(5) measuring the radiation intensities of the filtered wavelengths; and
(b
6) generating a sorting signal based on comparison of the measures of the radiation intensities with adjustable predetermined values.
2 Assignments
0 Petitions
Accused Products
Abstract
Disclosed is a process and apparatus to analyze metal particles to determine their composition and to generate a sorting signal. The particles are exposed to a pulsed laser beam by which they are partly vaporized to form a plasma so that the particles are cleaned and the cleaned area is subsequently partially vaporized by a pulsed laser beam to form a plasma. The spectral lines of the plasma are inspected for an identification of the composition of the metal particles. The required inspection rate of 30 particles per second can readily be achieved or even exceeded if a defined narrow wavelength range or a defined wavelength is filtered from the total radiation that is emitted by the plasma and the intensities of the filtered partial radiations are related to each other to obtain ratios, which are compared with adjustable limiting values. A sorting signal is derived from the result of said comparison. The inspection rate can be improved in that the partial radiation is subjected to a comparison only for a defined interval of time.
25 Citations
20 Claims
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1. A process of analyzing metal particles for their chemical composition by laser-induced breakdown spectroscopy and of generating a sorting signal, said process comprising:
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(1) irradiating the surface of a metal particle using a cleaning pulse from a first UV-gas-laser; (2) removing the plasma produced by the cleaning pulse using an air jet of at least 10 m/sec.; (b
3) producing a plasma by directing an analysis pulse from the first UV-gas-laser or another UV-gas-laser to the cleaned surface;(b
4) filtering predetermined, selectable wavelengths from the total radiation of the plasma produced by the analysis pulse;(5) measuring the radiation intensities of the filtered wavelengths; and (b
6) generating a sorting signal based on comparison of the measures of the radiation intensities with adjustable predetermined values. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. In a process of analyzing metal particles having an average size of from 15 to 65 mm and at a rate of at least 30 particles per second for their chemical composition by laser-induced breakdown spectroscopy (LIBS) and of generating a sorting signal, the improvement of
(1) using a pulsed UV-gas-laser; -
(2) irradiating a surface of the metal particles to partially clean the surface; (3) removing the plasma produced by the cleaning pulse with an air jet of at least 10 m/sec; (4) producing a plasma by directing a laser pulse to the cleaned surface, the plasma being characteristic of the metal particle composition; (5) filtering predetermined, selectable wavelengths from the total radiation of the plasma; (6) deriving numerical ratios from the radiation intensities of the filtered wavelengths; and (7) generating a sorting signal in dependence on a comparison of said derived ratios with adjustable limiting values. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification