Abstract: In the present invention, there is provided a removable cover for retaining off-gases inside a clarifier. The cover comprises trusses extending across the clarifier and a flexible sheet laid across the trusses. Structural angles enclose the clarifier and constitute a kick plate on the walkways around the clarifier for improving the safety of workers. One side of the flexible sheet is permanently affixed to a first wall of the clarifier. A series of pullers are mounted inside the structural angles for pulling and releasably sealing the three other sides of the flexible sheet against the outmost trusses and against a second wall of the clarifier opposite the first wall. Each puller has a cable-deflector bar extending substantially at a same level as a mounting surface of the puller for increasing an angle of downward pull on the flexible sheet. The flexible sheet is rolled-up along the trusses to expose. machinery inside the clarifier.

Abstract: In the present invention, there is provided a removable cover for retaining off-gases inside a clarifier. The cover comprises trusses extending across the clarifier and a flexible sheet laid across the trusses. Structural angles enclose the clarifier and constitute a kick plate on the walkways around the clarifier for improving the safety of workers. One side of the flexible sheet is permanently affixed to a first wall of the clarifier. A series of pullers are mounted inside the structural angles for pulling and releasably sealing the three other sides of the flexible sheet against the outmost trusses and against a second wall of the clarifier opposite the first wall. Each puller has a cable-deflector bar extending substantially at a same level as a mounting surface of the puller for increasing an angle of downward pull on the flexible sheet. The flexible sheet is rolled-up along the trusses to expose machinery inside the clarifier.

Abstract: In the present invention, there is provided a removable cover for retaining off-gases inside a clarifier. The cover comprises trusses extending across the clarifier and a flexible sheet laid across the trusses. Structural angles enclose the clarifier and constitute a kick plate on the walkways around the clarifier for improving the safety of workers. One side of the flexible sheet is permanently affixed to a first wall of the clarifier. A series of pullers are mounted inside the structural angles for pulling and releasably sealing the three other sides of the flexible sheet against the outmost trusses and against a second wall of the clarifier opposite the first wall. Each puller has a cable-deflector bar extending substantially at a same level as a mounting surface of the puller for increasing an angle of downward pull on the flexible sheet. The flexible sheet is rolled-up along the trusses to expose machinery inside the clarifier.