Gas distribution unit for fluidized bed reactor system, fluidized bed reactor system having the gas distribution unit, and method for preparing granular polycrystalline silicon using the fluidized bed reactor system

Patent metadata

Field	Value
Publication number	US-10518237-B2
Application number	US-201615549759-A
Country	US
Kind code	B2
Filing date	Mar 24, 2016
Priority date	Apr 1, 2015
Publication date	Dec 31, 2019
Grant date	Dec 31, 2019

Abstract

The present invention relates to a gas distribution unit for a fluidized bed reactor system, a fluidized bed reactor system having the gas distribution unit, and a method for preparing granular polysilicon using the fluidized bed reactor system. The gas distribution unit for a fluidized bed reactor system according to the present invention enables gas flow rate control and gas composition control for each zone within the plenum chamber. In addition, a fluidized bed reactor system having the gas distribution unit enables shape control of a fluidized bed (in particular, transition between a bubbling fluidized bed and a spout fluidized bed). The method for preparing granular polysilicon using the fluidized bed reactor system not only simultaneously improves process stability and productivity, but also enables more flexible handling in the event of an abnormal situation.

First claim

The invention claimed is:

1. A gas distribution unit ( 200 ) for a fluidized bed reactor system that injects a gas into a fluidized bed reaction chamber 100 via a plenum chamber ( 210 ) and a perforated plate ( 290 ),
wherein the plenum chamber ( 210 ) includes: a plurality of annular partition walls ( 220 ) arranged concentrically and spaced apart from each other; a plurality of annular spaces ( 230 ) partitioned by the annular partition walls and each independently having at least one gas inlet ( 232 ) and a plurality of gas outlets ( 235 ); a plurality of gas supply pipes ( 240 ) connected to the gas inlets ( 232 ) and independently supplying gas to the annular spaces ( 230 ); and a plurality of gas discharge pipes ( 250 ) connected to the respective gas outlets ( 235 ), and
wherein the perforated plate ( 290 ) is in contact with an end of the gas discharge pipes ( 250 ) of the plenum chamber ( 210 ) and has a plurality of openings corresponding to the gas discharge pipes ( 250 ).

2. The gas distribution unit for a fluidized bed reactor system according to claim 1 , wherein the plenum chamber ( 210 ) has 3 to 10 annular partition walls ( 220 ).

3. The gas distribution unit for a fluidized bed reactor system according to claim 1 , wherein the plurality of gas discharge pipes ( 250 ) have one or more shapes selected from the group consisting of a throttle nozzle, a venturi nozzle, and a jet nozzle.

4. The gas distribution unit for a fluidized bed reactor system according to claim 1 , wherein the gas distribution unit further includes a plurality of cooling channels ( 257 ) for cooling each gas discharge pipe adjacent to the plurality of gas discharge pipes ( 250 ).

5. The gas distribution unit for a fluidized bed reactor system according to claim 1 , wherein the perforated plate ( 290 ) has a shape in which the center is more concave than the edge.

6. The gas distribution unit for a fluidized bed reactor system according to claim 1 , wherein the gas distribution unit further includes an annular space located at a center of the concentric circle and a product collection pipe ( 260 ) passing through a center of the perforated plate.

7. A fluidized bed reactor system for the preparation of granular polysilicon, comprising:
the gas distribution unit ( 200 ) according to any one of claims 1 to 6 ;
a fluidized bed reaction chamber ( 100 ) disposed on the perforated plate of the gas distribution unit and having a silicon seed inlet;
a fluidizing gas tank ( 300 ) connected to gas supply pipes ( 240 ) of the gas distribution unit ( 200 ) via respective independent fluidizing gas flow rate controllers ( 350 );
a silicon source gas tank ( 400 ) connected to the gas supply pipes of the gas distribution unit ( 200 ) via respective independent silicon source gas flow rate controllers ( 450 ); and
a fluidized bed monitoring unit ( 500 ) for monitoring a state of the fluidized bed of the silicon seed formed in the fluidized bed reaction chamber ( 100 ) including a differential pressure due to a seed growth, a height variation of the fluidized bed, and a power change, and transmitting an electrical signal ( 530 ) to the respective fluidizing gas flow rate controllers ( 350 ) and the respective silicon source gas flow rate controllers ( 450 ) so as to control flow rates of the fluidizing gas and the silicon gas.

8. The fluidized bed reactor system for the preparation of granular polysilicon according to claim 7 , wherein the fluidized bed reaction chamber ( 100 ) includes a first body portion ( 110 ), a second body portion ( 120 ), and a head portion ( 130 ) which are sequentially connected to the perforated plate ( 290 ) of the gas distribution unit to form an inner space;
the first body portion ( 110 ) includes a plurality of reaction tubes ( 115 ) disposed radially and spaced apart from each other on the perforated plate and providing a plurality of reaction spaces connected to the second body portion ( 120 ), and a plurality of heating portions ( 117 ) surrounding at least a portion of the outer peripheral surface of the reaction tube ( 115 );
the second body portion ( 120 ) provides one reaction space connected to the plurality of reaction tubes ( 115 ) of the first body portion ( 110 ); and
the head portion ( 130 ) seals the upper portion of the fluidized bed reaction chamber ( 100 ) and has a larger diameter than the second body portion ( 120 ).

9. A method for preparing granular polysilicon using a fluidized bed reactor system, comprising:
supplying a fluidizing gas and a silicon source gas to the fluidized bed reaction chamber ( 100 ) to form a fluidized bed of a silicon seed;
depositing silicon on a surface of the silicon seed in contact with the silicon source gas to grow the silicon seed;
collecting the silicon seed of which fluidity has been reduced by the growth from the fluidized bed reaction chamber( 100 ); and
injecting the silicon seed into the fluidized bed reaction chamber( 100 ),
wherein the above steps are performed continuously and repeatedly, and
flow rates of the fluidizing gas and the silicon source gas supplied to the respective annular spaces through the gas supply pipes ( 240 ) are each independently controlled in accordance with a state of the fluidized bed monitored in the fluidized bed monitoring unit ( 500 ) of the fluidized bed reactor system,
wherein the fluidized bed reactor system comprise
the gas distribution unit ( 200 ) according to any one of claims 1 to 6 ;
a fluidized bed reaction chamber ( 100 ) disposed on the perforated plate of the gas distribution unit and having a silicon seed inlet;
a fluidizing gas tank ( 300 ) connected to gas supply pipes ( 240 ) of the gas distribution unit ( 200 ) via respective independent fluidizing gas flow rate controllers ( 350 );
a silicon source gas tank ( 400 ) connected to the gas supply pipes of the gas distribution unit ( 200 ) via respective independent silicon source gas flow rate controllers ( 450 ); and
a fluidized bed monitoring unit ( 500 ) for monitoring a state of the fluidized bed of the silicon seed formed in the fluidized bed reaction chamber ( 100 ) including a differential pressure due to seed growth, a height variation of the fluidized bed, and a power change and transmitting an electrical signal ( 530 ) to the respective fluidizing gas flow rate controllers ( 350 ) and the respective silicon source gas flow rate controllers ( 450 ) so as to control flow rates of the fluidizing gas and the silicon source gas.

10. The method for preparing granular polysilicon according to claim 9 , wherein the fluidized bed of the silicon seed includes:
a bubbling fluidized bed which is maintained at a height of 3 to 6 times the diameter of the fluidized bed reaction chamber ( 100 ), with more than 85 mol % of the fluidizing gas and less than 15 mol % of the silicon source gas being uniformly supplied to the plurality of annular spaces of the plenum chamber ( 210 ); and
a spout fluidized bed which is maintained at a height of 1.2 to 1.7 times an initial height of the bubbling fluidized bed, with less than 85 mol % of the fluidizing gas and 15 mol % or more of silicon source gas being supplied to an annular space located within ⅓ of the radius of the plenum chamber ( 210 ), and only the fluidizing gas being supplied to a remaining annular space,
wherein the bubbling fluidized bed and the spout fluidized bed are continuously and repeatedly transited over the entire preparing process, and
the silicon seed of which fluidity has been reduced by the growth can be collected in the section where the fluidized bed of the silicon seed is transited from the spout fluidized bed to the bubbling fluidized bed.

11. The me

Assignees

• Hanwha Chemical Corp

Inventors

• Ahn Gui Ryong
• Kim Sang Ah
• Kim Ji Ho
• Han Joo Hee
• Kim Gil Ho
• Lee Won Ik

Classifications

• C23C16/24

  Deposition of silicon only · CPC title

• C23C16/442

  using fluidised bed process · CPC title

• F27B15/10

  Arrangements of air or gas supply devices · CPC title

• C01B33/03

  by decomposition of silicon halides or halosilanes or reduction thereof with hydrogen as the only reducing agent · CPC title

• C23C16/4417

  Methods specially adapted for coating powder · CPC title