Large tank or sewage basin type cover - comprises sections retractable and extensible from sides to stretch across basin

摘要

The spread of odours or noxious vapours is prevented by a covering for large containers and basins, esp. sewage treatment plant in waste water disposal installations. Use is made of a series of lid-type elements spanning the basin across its width. The elements are telescopically retractable and extensible from one side of the basin. There may be two groups on opposite sides, connected to a shared travelling chassis frame, so that one group extends and the other retracts as it moves. Frame and/or elements can have wheels running on side tracks and/or pool edges.