Patent ID: 8714207

Claim:
A bulk storage container comprising, in combination: (a) a horizontal bottom wall and a round vertical side wall extending upward from the bottom wall, said walls defining a container space for a liquid; (b) a floating cover arranged within the side wall and configured to float on a surface of a liquid in the container, said cover being sealed in relation to the side wall by means of a flexible seal permitting vertical movement of the cover as the surface of a liquid in the container is raised and lowered, said cover having a plurality of open compartments on a lower side thereof facing such a liquid, if present, which are open toward such a liquid and which trap any gaseous media emanating from such a liquid; (c) a sensor device with at least three sensing elements located around a periphery of the cover for sensing the position of the cover with respect to the surface of such a liquid, if present; (d) a gas control unit having a gas compressor, a plurality of gas lines and a plurality of valves in said gas lines, said gas lines interconnecting the compressor and the plurality of open compartments on the lower side of the cover for controlling the gas pressure within said plurality of open compartments; wherein the gas control unit is responsive to the sensor device and operative to adjust the horizontal orientation of the cover through displacement of gaseous media between said plurality of open compartments.