US Patent 10325797 Purging device and purging method

Containers are purged between overhead transfer vehicles and a container transfer location to or from which the containers are transferred. A travelling rail for a local vehicle is provided below a travelling rail for the overhead transfer vehicles and above the container transfer location, and a local vehicle travels along the travelling rail and includes a hoist that raises and lowers the containers. A purging table that supports the containers is provided below the travelling rail for the local vehicle so as not to block a portion over the container transfer location and a purging gas feeding device feeds a purging gas into the containers supported on the purging table.