System for producing silicon granulates, comprises a device for granulating powdered silicon particles with a device for agglomeration the silicon particles and a device for melting the agglomerated silicon particles, and a cooling device

摘要

The system (1) comprises a device (3) for granulating powdered silicon particles with a device (6) for agglomeration the silicon particles and a device for melting the agglomerated silicon particles, and a cooling device (4) connected to the melting device for the solidification of the molten silicon droplets. The agglomeration device extends along a flow direction (5) and the melting device is connected to the agglomeration device in the flow direction. The agglomeration device has three sections with increasing smaller cross-section, where the sections are adjacent to each other. The system (1) comprises a device (3) for granulating powdered silicon particles with a device (6) for agglomeration the silicon particles and a device for melting the agglomerated silicon particles, and a cooling device (4) connected to the melting device for the solidification of the molten silicon droplets. The agglomeration device extends along a flow direction (5) and the melting device is connected to the agglomeration device in the flow direction. The agglomeration device has three sections with increasing smaller cross-section, where the sections are adjacent to each other in the flow direction. A deposition-reactor (2) for thermal decomposition of gases containing silicon is provided for the provision of the silicon particles for the granulating device. The agglomeration device is arranged between the deposition-reactor and the melting device, directly connects to the deposition-reactor at the outlet side and has an inductive heating element. An alternating magnetic field is produced in the agglomeration device using the inductive heating element in an area-wise manner. The granulating device is outwardly lockable in a gas-tight manner. The agglomeration device has a carrier gas inlet for supporting a flow of the silicon particle in the flow direction. The carrier gas inlet is a part of a closed gas circuit between the melting device and the agglomeration device. The melting device has an outlet arranged at both sides. A vertically aligned falling tower connects itself to the outlet for the solidification of the silicon molten in the melting device. The agglomeration device has a wall made of graphite, ceramic, silicon carbide, silicon nitride, inert metallic materials or quartzes. An independent claim is included for a method for producing silicon granulates.