Radiation-heated fluidized-bed reactor

Claim 2

A fluidized-bed reactor ( 1 ) comprising: a) a pressure-supporting enclosure ( 2 ); b) an inner reactor tube ( 3 ) within said enclosure ( 2 ) and made from a material which exhibits high transmission for thermal radiation; c) an inlet ( 4 ) at a top of said enclosure ( 2 ) for silicon particles ( 5 ); d) an inlet device ( 6 ) for supplying a reaction gas ( 7 ) which contains a silicon compound in gas or vapor form, the inlet device ( 6 ) being of tubular design and dividing the fluidized bed into zones consisting of a heating zone ( 17 ) and a separate reaction zone ( 18 ) situated above the heating zone, wherein the inlet device is positioned so that the reaction gas supplied by the inlet device does not enter the heating zone; e) a gas-distribution device ( 8 ) at a bottom of said enclosure ( 2 ) for feeding a fluidizing gas ( 9 ) into the heating zone; f) an outlet ( 10 ) at the top of said enclosure ( 2 ) for reaction gas which has not fully reacted, fluidizing gas and products of reaction ( 11 ) which are in gas or vapor form and collect above a fluidized-bed surface ( 19 ); g) an outlet ( 12 ) at the bottom of said enclosure ( 2 ) for a product ( 13 ); h) a heater device ( 14 ); i) an energy supply ( 15 ) for the heater device ( 14 ); and wherein the heater device ( 14 ) is a radiation source for thermal radiation which is arranged outside the inner reactor tube and as a cylinder around the heating zone ( 17 ), without being in direct contact with the inner reactor tube, and is designed in such a manner that it uses thermal radiation to heat the silicon particles in the heating zone to a temperature which is such that the reaction temperature is established in the reaction zone ( 18 ).

Claim 3

The fluidized-bed reactor as claimed in claim 1 , wherein a space between said inner reactor tube ( 3 ) and said pressure-supporting enclosure ( 2 ) is provided with thermal insulation ( 16 ).

Claim 4

The fluidized-bed reactor as claimed in claim 1 , wherein the heater device is formed over a large area around the entire heating zone and thus forms a cylindrical radiation source.

Claim 5

The fluidized-bed reactor as claimed in claim 1 , wherein the heater device emits thermal radiation with a wavelength of from 0.4 μm to 900 μm.

Claim 6

The fluidized-bed reactor as claimed in claim 4 , wherein the heater device emits thermal radiation with a wavelength of from 0.4 μm to 300 μm.

Claim 7

The fluidized-bed reactor as claimed in claim 1 , wherein the heater device is selected from the group consisting of a heater element made from doped silicon, a heater element made from graphite, a heater element made from silicon carbide, a quartz tube radiator, a ceramic radiator and a wire radiator.

Claim 8

The fluidized-bed reactor as claimed in claim 1 , wherein all components of the reactor which come into contact with product are selected from the group consisting of an inert material and a component coated with an inert material.

Claim 9

A fluidized-bed reactor ( 1 ) comprising: (a) a pressure supporting enclosure ( 2 ); (b) an inner reactor tube ( 3 ) within said enclosure ( 2 ) and made from a material which exhibits high transmission for thermal radiation; (c) an inlet ( 4 ) at a top of said enclosure ( 2 ) for silicon particles ( 5 ) (d) an inlet device ( 6 ) for supplying a reaction gas ( 7 ) which contains a silicon compound in gas or vapor form, the inlet device ( 6 ) being of tubular design and dividing the fluidized bed into a heating zone ( 17 ) and a reaction zone ( 18 ) situated above the heating zone; (e) a gas-distribution device ( 8 ) at a bottom of said enclosure ( 2 ) for feeding a fluidizing gas ( 9 ) into the heating zone; (f) an outlet ( 10 ) at the top of said enclosure ( 2 ) for reaction gas which has not fully reacted, fluidizing gas and products of reaction ( 11 ) which are in gas or vapor form and collect above a fluidized-bed surface ( 19 ); (g) an outlet ( 12 ) at the bottom of said enclosure ( 2 ) for a product ( 13 ); (h) a heater device ( 14 ); (i) an energy supply ( 15 ) for the heater device ( 14 ); and wherein the heater device ( 14 ) is a radiation source for thermal radiation which is arranged outside the inner reactor tube and as a cylinder around the heating zone ( 17 ), without being in direct contact with the inner reactor tube, and is designed in such a manner that it uses thermal radiation to heat the silicon particles in the heating zone to a temperature which is such that the reaction temperature is established in the reaction zone ( 18 ) and wherein the heater device is a tube with meandering slots made from graphite with a SiC surface coating which is arranged in the reactor, standing on or hanging from electrode terminals.

Claim 10

A fluidized-bed reactor ( 1 ) comprising: (a) a pressure supporting enclosure ( 2 ); (b) an inner reactor tube ( 3 ) within said enclosure ( 2 ) and made from a material which exhibits high transmission for thermal radiation; (c) an inlet ( 4 ) at a top of said enclosure ( 2 ) for silicon particles ( 5 ) (d) an inlet device ( 6 ) for supplying a reaction gas ( 7 ) which contains a silicon compound in gas or vapor form, the inlet device ( 6 ) being of tubular design and dividing the fluidized bed into a heating zone ( 17 ) and a reaction zone ( 18 ) situated above the heating zone; (e) a gas-distribution device ( 8 ) at a bottom of said enclosure ( 2 ) for feeding a fluidizing gas ( 9 ) into the heating zone; (f) an outlet ( 10 ) at the top of said enclosure ( 2 ) for reaction gas which has not fully reacted, fluidizing gas and products of reaction ( 11 ) which are in gas or vapor form and collect above a fluidized-bed surface ( 19 ); (g) an outlet ( 12 ) at the bottom of said enclosure ( 2 ) for a product ( 13 ); (h) a heater device ( 14 ); (i) an energy supply ( 15 ) for the heater device ( 14 ); and wherein the heater device ( 14 ) is a radiation source for thermal radiation which is arranged outside the inner reactor tube and as a cylinder around the heating zone ( 17 ), without being in direct contact with the inner reactor tube, and is designed in such a manner that it uses thermal radiation to heat the silicon particles in the heating zone to a temperature which is such that the reaction temperature is established in the reaction zone ( 18 ) and wherein the heater device is a tube with meandering slots made from graphite with a SiC surface coating which is arranged in the reactor, standing on or hanging from electrode terminals.