A system for growing silicon crystal structures includes a housing defining a growth chamber and a feed system connected to the housing for delivering silicon particles to the growth chamber. The feed system includes a container for holding the silicon particles. The container includes an outlet for discharging the silicon particles. The feed system also includes a channel connected to the outlet such that silicon particles discharged from the container flow through the channel. The feed system further includes a separation valve connected to the channel and to the housing. The separation valve is configured such that a portion of the feed system rotates relative to the housing.