Abstract: A pneumatic metering device for metering powdered materials, for example in connection with feeding aluminum oxide and aluminum fluoride to an electrolysis cell for production of aluminum, includes a container in the form of a relatively long, closed channel or similar structure. A fluidizing element is fitted in the base of the channel for supply of air for fluidization of material which is located in the channel. The container is fitted with an inlet for feeding material to the container from a store in the form of a silo or similar and an outlet for metered discharge of material from the container. The area below the inlet is inactive and is not supplied with fluidizing air, whereas air is supplied intermittently to the fluidizing element which is designed to cover essentially all other parts of the base of the channel.

Abstract: An apparatus having a closed channel or container for transporting and/or distributing fluidizable material includes an air- or gas-permeable wall arranged in the channel and forming a partition between an upper pathway for the fluidizable material and a lower flue to which is fed fluidizing gas from a gas source via a tube. An inlet is provided for feeding fluidizable material to the channel. The apparatus also includes one or more outlets for continual or intermittent run off of material from the channel, and a tube for ventilating the channel. The channel is equipped at its inlet with pipe stub extending into the upper pathway. An area defined under the pipe stub is inactive or is equipped with a separately arranged fluidizing wall with a separate gas feed.