Wacker Chemie Ag

Gerhard Forstpointner

Bernhard Baumann

Dirk Weckesser

Simon Pedron

Harald Hertlein

Rainer Hauswirth

Michael Fricke

Norbert Ellinger

Nobert Ellinger

A subject of the invention is a fluidized-bed reactor for producing granular polycrystalline silicon. The fluidized-bed reactor comprises a segmented reactor tube, which is disposed between a reactor top and a reactor bottom, a heating facility, at least one nozzle for supplying fluidizing gas, at least one nozzle for supplying reaction gas, a facility for supplying silicon seed particles, a product removal line, and an offgas removal line. The segmented reactor tube comprises a base segment and at least one spacer segment, there being disposed, between base segment and spacer segment, a flat seal made from a carbon-containing material, the spacer segment consisting of a material which, within a temperature range from 100 to 950&#xb0; C., has a thermal conductivity of &#x3c;2 W/mK.

Fluidized bed reactor for production of granular polycrystalline silicon

The fluidized bed process for preparing polysilicon by chemical vapor deposition is improved by positioning at least one Laval nozzle upstream from a gas inlet into the reactor.

Fluidized bed reactor and method for producing granular polysilicon

Contamination of fluidized bed-produced polycrystalline granules by phosphorus is reduced by employing as seals and/or packings, graphite containing &#x3c;500 ppmw of phosphorus.

Fluidized bed reactor and process for producing polycrystalline silicon granules

Silicon seed particles which can be used for producing polycrystalline silicon granules in a fluidized-bed reactor are prepared by a process wherein a milling gas stream is introduced into a chamber containing polycrystalline silicon granules, as a result of which individual particles of the polycrystalline silicon granules are accelerated in such a manner that they collide with other particles of the polycrystalline silicon granules, and in this manner the polycrystalline silicon granules are comminuted, wherein the milling gas stream is introduced into the chamber by at least one jet nozzle made of hard metal.

Silicon seed particles for the production of polycrystalline silicon granules in a fluidized bed reactor

Plastic material-comprising surfaces of a substrate are coated with elemental silicon by cold gas spraying by injecting a powder containing silicon into a gas and powder with a high velocity onto the substrate surface, such that the silicon forms a firmly adherent coat on the substrate surface comprising the plastics material. Apparatuses having such silicon-coated surfaces are useful in minimizing contamination of polycrystalline silicon production, processing, packaging, and transport.

Plastics material substrate having a silicon coating

Control of the flow of granular polysilicon granules is effected by employing an elastomeric pinch sleeve valve. The flow control by this method is especially useful for controlling the flow of silicon seed particles and granular polysilicon product in the fluidized bed method for producing polysilicon. The flow may be stopped without gas leakage, and is suitable for use over long operating campaigns.

Fluidized bed reactor with pinching fittings for producing polysilicon granulate, and method and use for same

Assembly of a fluidized bed reactor for the preparation of polycrystalline silicon granules by chemical vapor deposition of silicon onto seed particles and removal of polycrystalline silicon granules is facilitated without breakage and with gas tightness by a specific assembly sequence.

Fluidized bed reactor for producing polycrystalline silicon granules and method for the assembly of such a fluidized bed reactor

Silicon granules are conveyed in an encapsulated conveying channel by swaying movement of the channel produced by a permanent magnet excited by an external alternating electromagnetic field.

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Kastl, Germany

Gerhard Forstpointner