US 5,382,412 AGranted

Fluidized bed reactor heated by microwaves

AssigneeKorea Research Institute of Chemical Technology

InventorsHee Y. Kim, Yong M. Song, Jong Y. Jeon, Dae H. Kwon, Kang M. Lee, Jae S. Lee, Dong S. Park

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Abstract

An improved reactor for a high-temperature deposition reaction on seed particles is constructed with a fluidized bed which is divided into a heating zone and a reaction zone by a partition. Seed particles in the heating zone are fluidized by a carrier gas and are heated by microwaves. On the other hand, the reaction zone for the deposition reaction, through which reaction gases pass, is heated by particle mixing between the reaction zone and the upper section of the heating zone. Subsequently, a desired reaction temperature at the reaction zone is maintained stable without deteriorating the microwave heating of the heating zone.

Claims7

Dependent claims

Apparatus for preparing polycrystalline silicon comprising:

a fluidized bed reactor means;
means for introducing silicon particles into said reaction means;
partition means in said reactor means partitioning said reactor means into a reaction zone and a heating zone having an open upper end, said partition means precluding fluid communication and lateral penetration of silicon particles between said heating zone and said reaction zone other than through said oepn upper end of said heating zone;
first inlet means for introducing a reaction gas comprising a silicon source material into said reaction zone and for fluidizing silicon particles in said reaction zone such that said silicon source material is deposited as silicon metal on said silicon particles at a reaction temperature;
second inlet means for introducing a carrier gas into said heating zone and for fluidizing said silicon particles in said heating zone;
heating means for heating said silicon particles by microwave energy in said heating zone to a temperature above said reaction temperature such that said heated silicon particles in the upper section of said heating zone are mixed with said silicon particles in said reaction zone to thereby transfer the heat of said heated silicon particles in said heating zone to said reaction zone;
insulating means juxtaposed to said heating zone, said insulating means comprising microwave-transparent insulating material;
first outlet means on said reactor means for removing said silicon particles on which said silicon source material has been deposited;
and
second outlet means on said reactor means for removing unreacted fluidizing gases and reaction by-product gases from said reactor means.

7 more elements

Apparatus for preparing polycrystalline silicon comprising:

a fluidized bed reactor means;
means for introducing silicon particles into reaction means;
partition means in said reactor means partitioning said reactor means into a reaction zone and a heating zone having an open upper end, said partition means precluding fluid communication and lateral penetration of silicon particles between said heating zone and said reaction zone other than through said open upper end of said heating zone;
first inlet means for introducing a reaction gas comprising a silicon source material into said reaction zone and for fluidizing silicon particles in said reaction zone such that said silicon source material is deposited as silicon metal on said silicon particles at a reaction temperature;
second inlet means for introducing a carrier gas into said heating zone and for fluidizing said silicon particles in said heating zone;
heating means for heating said silicon particles by microwave energy in said heating zone to a temperature above said reaction temperature such that said heated silicon particles in the upper section of said heating zone are mixed with said silicon particles in said reaction zone to thereby transfer the heat of said heated silicon particles in said heating zone to said reaction zone;
said reactor means comprising a reactor vessel surrounded by containing means, said containing means being spaced from said reactor vessel to form a space about said reactor vessel, and insulating means within said space;
first outlet means on said reactor means for removing said silicon particles on which said silicon source material has been deposited;
and
second outlet means on said reactor means for removing unreacted fluidizing gases and reaction by-product gases from said reactor means.

7 more elements

A fluidized bed reactor in which a reaction gas comprising a source material is in a fluidized-bed relationship with seed particles on which said source material is to be deposited, comprising;

a fluidized-bed reactor vessel means having a first inlet means for said reaction gas and a second inlet means for seed particles;
partition means in said vessel means partitioning said vessel means into a heating zone and an operating zone, said heating zone having an open upper end, said partition means precluding fluid communication and lateral penetration of silicon particles between said heating zone and said operating zone other than through said open upper end of said heating zone;
said operating zone constituting a reaction zone in which there is a fluidized-bed relationship between said seed particles and said reaction gas;
said vessel means having third inlet means for introducing a carrier gas into said heating zone;
microwave heating means disposed externally of said heating zone operable to heat said heating zone;
said open upper end of said heating zone being in open communication with said operating zone;
containing means disposed about said vessel means, said containing means being spaced from said vessel means to form a space between said vessel means and said containing means, first insulating means disposed in one part of said space between said containing means and said lower section of said vessel means, and second insulating means disposed in another part of said space between said containing means and said vessel means;
first outlet means on said vessel means for removing said seed particles in which said source material has been deposited;
and
second outlet means on said vessel means for removing fluidizing gases and reaction by-product gases from said vessel means.

7 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/055,239Filed 28 Apr 1993 · continuation in part
Priority: 27 Oct 1992
Granted: 17 Jan 1995
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

B01J 8/42
According to "fluidised-bed" technique: with fluidised bed subjected to electric current or to radiations this sub-group includes the fluidised…
B01J 8/1854
With particles moving upwards while fluidised: followed by a downward movement inside the reactor to form a loop
B01J 19/126
Incoherent waves: microwaves
C01B 33/03
By decomposition or reduction of gaseous or vaporised silicon compounds other than silica or silica-containing material: by decomposition of…