Patent ID: 7029632

Claim:
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 ).