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US 7,029,632 B1Granted
Radiation-heated fluidized-bed reactor
AssigneeWacker Chemie AG
InventorsDieter Weidhaus, Alexander Hayduk
Life of this patent
Estimating the term…
Abstract
A radiation-heated fluidized-bed reactor and a process for producing high-purity polycrystalline silicon by using this reactor are provided. In this reactor, a heater device (14) is a radiation source for thermal radiation which is arranged outside the inner reactor tube and as a cylinder around the heater zone, without being in direct contact with the inner reactor tube. The inner reactor tube 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.
Claims8
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).
8 more elements
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.
8 more elements
Dependencies are inferred from the claim text.