Humidified sweep gas for dedusting process
AssigneeREC Silicon Inc
InventorRobert J. Geertsen
Life of this patent
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Abstract
Methods and apparatus for separating polysilicon powder from a mixture of granular polysilicon and polysilicon powder are disclosed. The method includes tumbling the polysilicon material in a tumbling device while flowing humidified sweep gas through the tumbling device. Also disclosed are compositions including granulate polysilicon or polycrystalline silicon, in some examples, including a coating layer consisting essentially of water.
Claims26
A tumbling device for separating granular polysilicon and polysilicon powder, the tumbling device comprising:
- a tumbler drum comprising:
- a first end wall,
- a second end wall,
- a side wall that extends between the end walls and together with the end walls defines a chamber, and
- the side wall, the first end wall, the second end wall, or a combination thereof defining a gas inlet and a gas outlet, with the inlet and the outlet being at spaced apart locations;
- a source of sweep gas in fluid communication with the inlet;
- a water vapor source that is in fluid communication with the source of sweep gas;
- and
- a source of motive power operable to rotate the tumbler drum about an axis of rotation that extends longitudinally through the chamber.
8-9. (canceled)
A method for separating polysilicon powder from a mixture of granular polysilicon and polysilicon powder, comprising:
- introducing a polysilicon material that is a mixture of granular polysilicon and polysilicon powder into a separating device that comprises a chamber in which the mixture is located;
- energizing the separating device for a period of time;
- providing humidified sweep gas in the chamber while the separating device is energized, thereby entraining separated polysilicon powder in the humidified sweep gas;
- and
- passing the humidified sweep gas and the entrained polysilicon powder out of the chamber, whereby at least a portion of the polysilicon powder is separated from the granular polysilicon.
15-16. (canceled)
18-25. (canceled)
A composition comprising a composite particle of spheroidal shape comprising a core surrounded by a core coating layer, wherein:
- the core comprises polycrystalline silicon having a purity of at least 99.999 wt % and a chlorine content of less than 10 ppm by weight;
- and
- the core coating layer is a film consisting essentially of water, wherein the layer is 5-100 Å thick,
- wherein the composite particle is present in the composition in at least 99.9 wt % based on the total weight of the composition.
28-29. (canceled)
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Dependencies are inferred from the claim text.