Fluidized bed reactor systems and distributors for use in same
View Patent ↗Fluidized bed reactor systems and distributors are disclosed as well as processes for producing polycrystalline silicon from a thermally decomposable silicon compound such as trichlorosilane. The processes generally involve reduction of silicon deposits on reactor walls during polycrystalline silicon production by use of a silicon tetrahalide.
1. A distributor for distributing a first gas and a second gas and a third gas into a reaction chamber comprising at least one reaction chamber wall, the distributor comprising a plurality of distribution openings including a plurality of peripheral openings, a plurality of interior openings and a plurality of central openings, each distribution opening having a channel portion and a flare-out portion and a throttle portion disposed between the channel portion and flare-out portion, the peripheral openings having channel portions that are angled toward the interior openings from the bottom to the top of the distributor, and throttle portions and flare-out portions that are parallel with a longitudinal axis of the distributor, wherein the peripheral openings are configured to provide fluid communication with the source of first gas and not the source of second gas or the source of third gas.
2. The distributor as set forth in claim 1 wherein the central openings are configured to provide fluid communication with the source of third gas but not the source of first gas or the source of second gas.
3. The distributor as set forth in claim 1 wherein the interior openings are configured to provide fluid communication with the source of second gas and not the source of first gas or the source of third gas.
4. A fluidized bed reactor system comprising a reaction chamber comprising at least one reaction chamber wall and a distributor for distributing gas into the reaction chamber and comprising a plurality of distribution openings which provide fluid communication between the reaction chamber and a source of a first gas, a source of a second gas and a source of third gas, each distribution opening having a channel portion, a flare-out portion and a throttle portion disposed between the channel portion and flare-out portion, the distributor having a plurality of cones, the flare-out portion being in fluid communication with the throttle portion of the distribution opening and a cone, the plurality of distribution openings comprising a plurality of peripheral openings having channel portions that are angled toward the interior openings from the bottom to the top of the distributor, and throttle portions and flare-out portions that are parallel with a longitudinal axis of the distributor, a plurality of interior openings and a plurality of central openings, wherein the peripheral openings are configured to provide fluid communication with the source of first gas and not the source of second gas or the source of third gas.
5. The fluidized bed reactor system as set forth in claim 4 wherein the central openings are configured to provide fluid communication with the source of third gas but not the source of first gas or the source of second gas.
6. The fluidized bed reactor system as set forth in claim 4 wherein the interior openings are in fluid communication with the source of second gas and are not in fluid communication with the source of first gas or the source of third gas.
7. The fluidized bed reactor system as set forth in claim 4 comprising a first gas plenum in fluid communication with the source of first gas and the reaction chamber, a second gas plenum in fluid communication with the source of second gas and the reaction chamber and a third gas plenum in fluid communication with the source of third gas and the reaction chamber.
8. The fluidized bed reactor system as set forth in claim 7 further comprising an inlet block, an outer ring, an interior ring concentric to the outer ring and a central ring concentric to the outer ring and interior ring and wherein the first gas plenum is defined by the space between the distributor, inlet block, outer ring and interior ring and the second gas plenum is defined by the space between the distributor, inlet block, interior ring and central ring.
9. The fluidized bed reactor system as set forth in claim 8 further comprising a product withdrawal tube concentric to the outer ring, interior ring and central ring and that extends through the distributor and inlet block and wherein the third gas plenum is defined by the space between the distributor, inlet block, central ring and the product withdrawal tube.
10. The fluidized bed reactor system as set forth in claim 9 wherein the inlet block comprises a first gas channel in fluid communication with the first gas plenum, a second gas channel in fluid communication with the second gas plenum and a third gas channel in fluid communication with the third gas plenum.
11. The fluidized bed reactor system as set forth in claim 4 wherein the cones that are in fluid communication with the flare-out portion of the peripheral distribution openings open into the reaction chamber.
12. The fluidized bed reactor system as set forth in claim 1 wherein the peripheral openings are disposed in a beveled portion of the distributor and direct the first gas parallel to the reaction chamber wall.
13. The distributor of claim 1 further comprising a plurality of cones, the flare-out portion being in fluid communication with the throttle portion of the distribution opening and the cone.
14. The distributor of claim 1 further comprising a product withdrawal tube extending at least partially through the distributor for the removal of product particles.
15. The distributor of claim 1 further comprising a cooling channel extending through the distributor.
16. The distributor of claim 1 wherein the longitudinal length of the channel is substantially greater than the longitudinal length of the flare-out portion.
17. The distributor of claim 1 further comprising an annular recess for receiving an annular ring to maintain separation of the first gas and the second gas prior to entering the distributor.