US Patent 9260050 Collection tank

A collection tank for use in a vacuum operated earth reduction system, the collection tank comprising a closed first end, an open second end defining a tank sealing flange and a body extending between the closed first end and the open second end. An internal chamber defined by the body, the closed first end and the open second end has a door coupled to the open second end and is configured to releasably seal the open second end. An automated door closer is coupled to a center of the door, wherein the automated door closer provides a closing force at the center of the door so that the closing force is equally distributed about a periphery of the door to seal the door against the tank sealing flange.