| 摘要 |
The invention relates to overhead covers of structures for use in purification of waste waters. The overhead cover of water surface is made compound from three concentric rings - central, medium and peripheral. The central ring of the overhead cover is stationary and secured on the central axis of the settling tank. The peripheral ring is also stationary and secured to a collar. The medium ring is arranged on the water surface and has a connection with a swinging frame allowing the cover to move together with the frame relative to the central and peripheral rings. The cover rings are arranged with an overlap to each other, a clearance between the medium ring and the central and peripheral rings is tightened by rubber seals to avoid smells and expulsion of waste waters discharges. The rings are made compound as sections. The sections of the central ring are rigidly connected by bolts, wherein sections of the medium ring are made as several hermetic chambers and have a movable loop joint providing "flexibility" of the structure required for emptying of the tank so that the cover, when putting down, took its configured profile. A scraper system is provided at the central and peripheral rings for avoiding snow storing during winter period. Scrapers rotate together with the frame and used for removing snow from the central and peripheral rings by dropping thereof on the medium ring, wherein snow is further moved to the clearance between movable and stationary rings, after which is dropped down to water using a system of stationary scrapers. Said scrapers are secured equally distant to the stationary central and peripheral rings in several spots over the tank diameter and inclined towards the clearance between the movable and stationary rings of the overhead cover. |
