# US 10,478,860 B2 · Device and method for the flexible classification of polycrystalline silicon fragments > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,478,860 B2 - Document ID: US10478860B2 - Status: Granted - Kind: B2 - Application number: 12/296,219 - Filed: 2007-03-28 - Published: 2009-05-14 - Granted: 2019-11-19 - Earliest claimed: 2006-04-06 - Assignees: Wacker Chemie AG - Applicants: Marcus Schaefer; Reiner Pech - Inventors: Marcus Schaefer; Reiner Pech - Web page: https://patentgrep.com/patent/US10478860B2 ## CPC - B07B 1/00: Sieving, screening, sifting, or sorting solid materials using networks, gratings, grids, or the like {(ash-sifters for domestic stoves or ranges F24B15/007)} - B07B 13/003: {Separation of articles by differences in their geometrical form or by difference in their physical properties, e.g. elasticity, compressibility, hardness} - B07B 13/04: according to size - B07B: SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL (wet separating processes, sorting by processes using fluent material in the same way as liquid B03; combinations of dry separating apparatus with wet separating apparatus B03B; using liquids B03B, B03D; sorting by magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high voltage electric fields B03C; centrifuges or vortex apparatus for carrying out physical processes B04; hand sorting, postal sorting, sorting by switching or other devices actuated in response to detection or measurement of some feature of articles or samples of material B07C) ## Abstract Polycrystalline silicon fragments are sorted into defined particle fractions in a flexible manner independent of initial particle size distribution and desired fraction size by a first mechanical screening into a fine fraction and residual fraction, followed by optoelectronic sorting of the residual fraction. ## Claims ### Claim 1 A device for the classification of crushed polysilicon fragments comprising: a) a mechanical screening system comprising at least one screen having fine holes which removes fine polysilicon fragments from the screen through the holes and leaves a residual polysilicon component, b) an optoelectronic sorting system which classifies the residual polysilicon component into a plurality of fractions of different sizes. ### Claim 2 (depends on 1) The device of claim 1, wherein the screen has a screening surface wherein the fine holes are in the form of a mesh. ### Claim 3 (depends on 1) The device of claim 1, which comprises a multistage mechanical screening system with a plurality of screens in succession, each successive screen of the plurality of screens having a screening surface with smaller hole sizes as compared to a next prior screen, and a multistage optoelectronic sorting system. ### Claim 4 (depends on 1) The device of claim 1, wherein the mechanical and/or optoelectronic separating devices are arranged in a tree structure. ### Claim 5 (depends on 1) The device of claim 1, wherein the mechanical screening system comprises an oscillatory screen driven by an unbalance motor. ### Claim 6 (depends on 1) The device of claim 1, wherein the screens of the mechanical screening system are arranged in more than one stage. ### Claim 7 (depends on 1) The device of claim 1, wherein two optoelectronic sorting systems are used. ### Claim 8 (depends on 1) The device of claim 1, wherein three or more optoelectronic sorting systems are used. ### Claim 9 (depends on 1) The device of claim 1, further comprising a superordinate controller with adjustable sorting parameters according to which the polysilicon fragments are sorted, and/or adjustable system parameters which affect the delivery of the poly fragments, such that individual sorting stages of the device may be altered to provide at least one defined polysilicon fraction. ### Claim 10 (depends on 1) The device of claim 1, wherein at least one parameter according to which the polysilicon fragments are sorted is selected from the group consisting of length, area, morphology, color, and shape of the polysilicon fragments. ### Claim 11 (depends on 1) The device of claim 1, further comprising at least one oscillatory delivery trough, wherein following removal of fine silicon fragments, fragments which constitute the residual component are spatially separated from other fragments on the oscillatory delivery trough prior to classifying by an optoelectronic sorting system. ### Claim 12 (depends on 1) The device of claim 1 having a plurality of optoelectronic sorting stages, each stage immediately preceded by an oscillatory delivery trough which spatially separates fragments of the residual component prior to free fall through the respective optoelectronic sorting system. ### Claim 13 (depends on 1) The device of claim 1, wherein the superordinate controller varies one or more of: the throughput of one or more delivery troughs; the oscillating frequency of one or more mechanical screens; the sorting parameters; the pressure at ejection blower nozzles. ### Claim 14 (depends on 9) The device of claim 9, wherein the mechanical screening system and/or the optoelectronic sorting system are provided with a measuring instrument for at least one defined parameter of classified polysilicon fragments, this measuring instrument connected by means of the controller to a control and regulating instrument which statistically evaluates measured parameters and compares them with predetermined parameters, and which in the event of a discrepancy between a measured parameter and a predetermined parameter, varies the sorting parameters of the optoelectronic sorting system or the entire sorting system so that the parameter then measured approximates the predetermined parameter. ### Claim 15 (depends on 1) The device of claim 1, wherein at least one magnetic extractor is positioned between individual sorting stages. ### Claim 16 A method for the flexible classification of crushed polysilicon comprising: first classifying the crushed polysilicon with a mechanical screening system comprising at least one screen having fine holes, removing fine polysilicon fragments through the holes, and leaving a residual polysilicon component on the mechanical screening system; and classifying the residual polysilicon component from the mechanical screening system into a plurality of fractions of different fragment sizes by an optoelectronic sorting system. ### Claim 17 (depends on 16) The method of claim 16, further comprising classifying a fine fraction removed from the crushed polysilicon from the mechanical screening system into at least two fractions of different fragment sizes by at least one further mechanical screening system having a screen with holes. ### Claim 18 (depends on 16) The method of claim 16, wherein the residual component is first optoelectronically sorted into two fractions of different particle sizes, and the two fractions are further optoelectronically sorted into four fractions, each of the four fractions having different particle sizes. ### Claim 19 (depends on 16) The method of claim 16, comprising separating the fragments into a screened fine fraction and a residual component by a mechanical screening system having at least one screen with holes, classifying the screened fine fraction into a fraction 1, and a fraction 2 having a smaller fragment size than a fraction size of fraction 1, by means of a further mechanical screening system, and separating the residual component into two fractions by means of optoelectronic sorting, these two fractions respectively being subdivided into four further fractions 3 to 6 by means of further optoelectronic sorting. ### Claim 20 (depends on 19) The method of claim 19, wherein the screened fine fraction has particle sizes of less than 20 mm, the residual component has particle sizes of more than 5 mm, fraction 1 has particle sizes of less than 10 mm, fraction 2 has particle sizes of from 2 mm to 20 mm, fraction 3 has particle sizes of from 5 mm to 50 mm, fraction 4 has particle sizes of from 15 mm to 70 mm, fraction 5 has particle sizes of from 30 mm to 120 mm and fraction 6 has particle sizes of more than 60 mm, the particle sizes being a length which includes 85 weight percent of the particles in the respective fraction. ### Claim 21 (depends on 19) The method of claim 19, wherein the fraction with the larger particle number in relation to the respective sorting parameter is displaced pneumatically in response to optoelectronic sorting. ### Claim 22 (depends on 16) The method of claim 16, further comprising spatially separating fragments of the residual component from each other prior to the residual component entering the optoelectronic sorting system for classifying the residual component. ### Claim 23 (depends on 16) The method of claim 16, wherein more than one optoelectronic sorting stage is used, and a plurality of optoelectronic sorting stages are each preceded by an oscillatory delivery trough which spatially separates fragments delivered to the associated optoelectronic sorting stage prior to classification of the fragments by the associated optoelectronic sorting stage.