Fluidized-Bed Reactor With Zone Heating

Deposition of silicon on wall suppressed. In new fluidized bed, silicon seed particles heated in uppermost zone of reactor. Hot particles gradually mix with lower particles and descend through fluidized bed. Lower wall of vessel kept relatively cool. Because silane enters at bottom and circulates through reactor pyrolized to silicon at high temperatures, silicon deposited on particles in preference wall. Design of fluidized bed for production of silicon greatly reduces tendency of silicon to deposit on wall of reaction vessel.