초록 ▼

Fluidized bed reactor systems for producing high purity silicon-coated particles are disclosed. A vessel has an outer wall, an insulation layer inwardly of the outer wall, at least one heater positioned inwardly of the insulation layer, a removable concentric liner inwardly of the heater, a central

Fluidized bed reactor systems for producing high purity silicon-coated particles are disclosed. A vessel has an outer wall, an insulation layer inwardly of the outer wall, at least one heater positioned inwardly of the insulation layer, a removable concentric liner inwardly of the heater, a central inlet nozzle, a plurality of fluidization nozzles, at least one cooling gas nozzle, and at least one product outlet. The system may include a removable concentric sleeve inwardly of the liner. In particular systems the central inlet nozzle is configured to produce a primary gas vertical plume centrally in the reactor chamber to minimize silicon deposition on reactor surfaces.

대표청구항 ▼

1. A process for producing high purity silicon-coated particles comprising: providing a bed of seed particles inside a gas-tight chamber defined within a vessel having (a) a bottom head, (b) a generally tubular side wall that surrounds a generally vertically extending centerline, (c) a solitary cent

1. A process for producing high purity silicon-coated particles comprising: providing a bed of seed particles inside a gas-tight chamber defined within a vessel having (a) a bottom head, (b) a generally tubular side wall that surrounds a generally vertically extending centerline, (c) a solitary central inlet nozzle having an opening that is upwardly facing, the solitary central inlet nozzle further comprising an inner wall and an outer wall positioned concentrically around the inner wall, (d) a plurality of fluidization nozzles, each fluidization nozzle having an opening that is upwardly facing and is located at an elevation below the elevation of the opening of the solitary central inlet nozzle; and (e) one or more cooling gas nozzles extending radially into the chamber through the general tubular side wall above the bottom head and below and below the plurality of fluidization nozzles;flowing hydrogen, inert gas, or a mixture thereof through the one or more cooling gas nozzles into the chamber at ambient temperature and at insufficient velocity to fluidize the bed;flowing gas upwardly through the chamber at sufficient velocity to fluidize the bed, with at least a portion of the gas being provided by introducing a stream of silicon-bearing gas into the chamber through a passageway defined by the inner wall of the solitary central inlet nozzle and a flow of a secondary gas comprising hydrogen, inert gas, or a mixture thereof through an annular passageway between the inner wall and the outer wall of the solitary central inlet nozzle;injecting streams of hydrogen, inert gas, or a mixture thereof into the chamber through the plurality of fluidization nozzles, the opening of each fluidization nozzle being positioned and the gas flow being regulated such that the streams contain the injected stream of silicon-bearing gas in a plume at a core region of the chamber near the centerline; andheating the contents of the chamber sufficiently that silicon is released from the silicon-bearing gas and deposited onto the seed particles to produce silicon-coated product particles. 2. The process of claim 1 wherein the solitary central inlet nozzle is located such that the centerline extends through the opening of the nozzle. 3. The process of claim 1 wherein the side wall is generally circular in horizontal cross-section at the elevation of the opening of the solitary central inlet nozzle. 4. The process of claim 1 wherein the outlets of the plurality of fluidization nozzles are horizontally displaced from the opening of the solitary central inlet nozzle. 5. The process of claim 1, further comprising withdrawing silicon-coated product particles through a product outlet in the bottom head. 6. The process of claim 1 wherein the silicon-bearing gas within the passageway defined by the inner wall of the solitary central inlet nozzle has a temperature at which the silicon-bearing gas does not compose. 7. The process of claim 1 wherein the plurality of fluidization nozzles surround and are laterally displaced from the solitary central inlet nozzle. 8. The process of claim 1 wherein heating the contents of the chamber sufficiently comprises heating the chamber to a temperature within a range of 620-760° C. as measured above the solitary central inlet nozzle opening at the vertically extending centerline. 9. The process of claim 1 wherein a temperature within the chamber in a region between the one or more cooling gas nozzles and the bottom head is maintained within a range of 50-100° C. 10. The process of claim 1 wherein a temperature within the chamber in a region between the one or more cooling gas nozzles and an opening of the one or more fluidization nozzles is maintained within a range of 50-700° C. 11. The process of claim 1 wherein a majority of the volume of silicon-bearing gas admitted into the chamber is injected through the solitary central inlet nozzle. 12. The process of claim 11 wherein all of the volume of silicon-bearing gas admitted to the chamber is injected through the solitary central inlet nozzle. 13. The process of claim 1 wherein the silicon-bearing gas is provided by a primary gas comprising the silicon-bearing gas and hydrogen. 14. The process of claim 13 wherein the silicon-bearing gas is silane, and the silane and hydrogen are present in a ratio from 1:1 to 9:1 by volume. 15. The process of claim 1 wherein the one or more cooling gas nozzles are positioned to provide a cooling gas flow that is countercurrent to a flow of the silicon-coated product particles. 16. The process of claim 15 wherein the one or more cooling gas nozzles are positioned such that the cooling gas flow cools the silicon-coated product particles prior to withdrawal through a product outlet in the bottom head. 17. The process of claim 15 wherein the countercurrent flow of the cooling gas carries fine silicon particles upward into the fluidized bed. 18. A process for producing high purity silicon-coated particles comprising: providing a bed of seed particles inside a gas-tight chamber defined within a vessel having (a) a bottom head, (b) a generally tubular side wall that surrounds a generally vertically extending centerline, (c) a solitary central inlet nozzle having an opening that is upwardly facing, the solitary central inlet nozzle further comprising an inner wall and an outer wall positioned concentrically around the inner wall, (d) a plurality of fluidization nozzles, each fluidization nozzle having an opening that is upwardly facing and is located at an elevation below the elevation of the opening of the solitary central inlet nozzle; and (e) one or more cooling gas nozzles extending radially into the chamber through the general tubular side wall above the bottom head and below and below the plurality of fluidization nozzles;flowing hydrogen, inert gas, or a mixture thereof through the one or more cooling gas nozzles into the chamber at ambient temperature and at insufficient velocity to fluidize the bed;flowing gas upwardly through the chamber at sufficient velocity to fluidize the bed, with at least a portion of the gas being provided by introducing a stream of primary gas comprising silane and hydrogen in a ratio of 1:1 to 9:1 by volume into the chamber through a passageway defined by the inner wall of the solitary central inlet nozzle and a flow of a secondary gas comprising hydrogen, inert gas, or a mixture thereof through an annular passageway between the inner wall and the outer wall of the solitary central inlet nozzle;injecting streams of hydrogen, inert gas, or a mixture thereof into the chamber through the plurality of fluidization nozzles, the opening of each fluidization nozzle being positioned and the gas flow being regulated such that the streams contain the injected stream of primary gas in a plume at a core region of the chamber near the centerline; andheating the contents of the chamber sufficiently that silicon is released from the silane and deposited onto the seed particles to produce silicon-coated product particles.