Patent ID: 8747757

Claim:
An apparatus for preparing granular polysilicon comprising a fluidized bed reactor which comprises: a reactor tube; a reactor shell enclosing the reactor tube; a fluidizing gas supplying means, wherein means, and means hereafter, is defined as a plate and holes or a plate and holes and nozzles, comprising a gas distributing means for supplying a fluidizing gas to a bottom cross-section of a bed of silicon particles, wherein the bed of silicon particles is formed within the reactor tube with the bottom cross-section of the bed being supported by the gas distribution means; a reaction gas supplying means installed vertically within the bed of silicon particles for supplying a reaction gas required for silicon deposition into the bed of silicon particles, wherein the reaction gas supplying means is extended upward from the gas distributing means, with a first intersection being defined, in plan view, between the reaction gas supplying means and the gas distribution means, and a reaction gas outlet, wherein outlet, and outlets hereafter, is defined as a hole or a hole and nozzles, of the reaction gas supplying means is located higher than a plurality of fluidizing gas outlets of the gas distributing means; an internal heater, comprising a plurality of heater units, which is vertically extended upward from the gas distribution means, with a second intersection being defined, in plan view, between the internal heater and the gas distribution means, and installed, in between the reaction gas supplying means and the inner wall of the reactor for heating the fluidizing gas and the silicon particles, wherein the height of the internal heater is not higher than the height of the reaction gas outlet; a plurality of fluidizing gas outlets provided, in plan view, substantially uniformly over a cross-section of the gas distribution means except for the first intersection and the second intersection; a reaction zone and a heating zone, which represent the upper and lower spaces in the reactor tube, respectively, with the height of the reaction gas outlet being selected as the reference height separating the reaction zone and the heating zone; a gas discharging means for discharging an off-gas comprising the fluidizing gas passing through the reaction zone, an unreacted reaction gas and a reaction byproduct gas out of the fluidized bed reactor; a particle discharging means for discharging a part of the silicon particles prepared in the reactor tube by the silicon deposition out of the fluidized bed reactor as silicon product particles; and wherein the gas distributing means comprised in the fluidizing gas supplying means comprises a gas distribution plate in the form of a grid, a disc or a conical plate or a gas distribution assembly plate having a plurality of holes for the distribution of the fluidizing gas at the bottom of the heating zone or comprises a plurality of fluidizing gas supplying holes and nozzles.