EA017108B1 - Overhead cover for radial settling tank - Google Patents

Abstract

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.

Description

The invention relates to the field of ceilings of wastewater treatment plants.

Known overlapping of the dome type of the company S. E. Ma1eg (Germany), used for radial sedimentation tanks of various diameters. This overlap is stationary and has the shape of a dome with support on the sides of the channel. The disadvantage of dome type ceilings is the impossibility of installing it on existing bowl sumps, due to the need for an additional foundation capable of supporting the weight of the ceilings. Another disadvantage of domed ceilings is the very expensive and time-consuming installation, requiring large free areas around the bowl of the sump, which is often impossible for finished treatment plants. The domed ceiling completely eliminates the possibility of overhauling equipment installed inside the sump bowl without resorting to the complete dismantling of the ceiling. An extremely effective air filtration and purification system is needed not only at the exit from under the ceiling, but also inside the dome, to ensure the normal operation of staff. The organization of such an air filtration and purification system is extremely complex and entails high operating costs.

A floating pontoon type ceiling is known to be used in oil storage tanks to reduce fumes. This overlap acts as a gas barrier, reducing vapor loss by up to 99%. Overlap is a set of sealed metal floats, covered from above with metal sheets. With full drainage of the tank, this overlap falls on the vertical supports provided at the bottom. The disadvantage of this overlap is the impossibility of its use for wastewater treatment plants. The presence of vertical supports on the bottom, on which the overlap rests when emptying the sump, is completely excluded, due to the constant rotation of the truss and the presence of underwater moving parts inside the bowl. The sedimentation tanks have a broken bottom profile, which this overlap is not able to repeat. In addition, for the normal operation of treatment facilities, the surface of the water in the sump must remain clean, while the cavities between the metal floats will contribute to fouling and debris. This type of overlap is designed for closed containers, not suitable for outdoor use and not designed for heavy loads, which completely excludes its use in the winter.

The technical results to which the invention is directed are:

1) increasing environmental friendliness by eliminating foul-smelling fumes from a liquid mirror;

2) the installation of the ceiling should not require a change in the existing design of the sump bowl;

3) the overlap should ensure the normal operation of equipment located inside the overlapped tank;

4) if it is necessary to empty the sump, the ceiling should lie on the bottom, repeating its profile and provide access to the equipment installed inside the bowl;

5) the overlap should have minimal operating costs and be adapted to work in the winter period.

Technical results are achieved as follows. The radial sump, which is a bowl with a central support-tower, in a circular way, an annular tray, inside which equipment is installed, for example, a silo scraper with a truss and a drive, has a water mirror overlap, which is made up of three rings - central, middle and peripheral. The central and peripheral rings are fixedly mounted, respectively, on the support tower and the peripheral part of the tank body, and the middle ring is mounted on a water mirror and has a connection to the silo scraper truss, allowing the overlap to move with the truss relative to the central and peripheral rings.

Each overlap ring is made prefabricated in the form of sections. The sections of the central and peripheral rings are rigidly connected to each other by bolted connections, and the sections of the middle overlap ring have a movable connection.

Each section of the middle overlap ring is made in the form of a series of sealed chambers to ensure positive buoyancy of the middle ring. The lower surface of the floor is smooth, without voids and has constant contact with water.

The sections of the central, middle and peripheral rings are made of stainless steel.

Using the proposed overlap allows you to increase environmental friendliness, eliminating the problem of foul-smelling fumes, due to the complete overlap of the sump. The overlap is made of three rings - central, middle and peripheral. The central overlap ring is fixed and mounted on the central support tower of the sump. The peripheral overlap ring is also stationary and is mounted on the peripheral part of the sump bowl, resting on the treadmill and the annular tray. The middle ring is mounted on a water mirror and has a connection to the silo scraper truss, which allows the ceiling to move with the truss relative to the central and peripheral rings.

The overlap rings are overlapped relative to each other. Clearance between movable and non

- 1 017108 the movable overlapping rings are closed with a rubber seal to prevent the escape of wastewater vapors and odors. Such a design of the overlap eliminates the contact of the water mirror with the atmosphere, i.e. ingress of vapors and odors into it, and ensure operability when changing the level of wastewater in the radial sump.

Each overlap ring is made prefabricated in the form of sections. The sections of the central and peripheral overlapping rings are a metal frame, covered from above with a steel sheet. The sections of the middle ring are made of independent sealed chambers, which are a box of rectangular cross section. The implementation of each section of the middle overlap ring in the form of independent sealed chambers can improve the reliability of the overlap and its maintainability. Due to the fact that the installation of the ceiling is carried out in small sections, there is no need to empty the sump or use expensive lifting equipment. Overlapping allows its installation without changing existing designs of sump bowls.

The lower surface of the middle overlap ring is smooth, without voids and has constant contact with water, which eliminates the accumulation of debris and fat deposits under the overlap.

The central and peripheral rings are rigidly connected to each other through bolted connections. The middle overlap ring has a movable loop connection of the sections, which, when emptying the sump, goes to the bottom, repeating its uneven profile and providing access to the equipment installed inside.

The water temperature in the sump is + 18 ° С all year round, which ensures snow melting on the middle floating part of the ceiling. To prevent snow accumulation in winter, a scraper system is provided on the peripheral and central overlapping rings. On a triangular sludge scraper farm there are a number of scrapers with a slope towards the middle overlap ring, rotating with it. Scrapers are designed to remove snow from the central and peripheral overlapping rings by dropping it onto the middle ring. From the middle overlap ring, snow is raked to the gap between the movable and fixed overlap rings, after which it is discharged into the water thanks to the system of fixed scrapers. Fixed scrapers are attached with equal pitch in several places along the diameter of the settler to the fixed peripheral and central overlap rings with a slope towards the gap between the movable and fixed overlap rings. Fixed scrapers are located with a different gap from the plane of the central ring for more uniform removal of snow.

The above shows that the combination of the claimed features ensures the achievement of the goals.

In FIG. 1 shows a general view of a radial sump with an overlap;

in FIG. 2 is a section AA in FIG. one;

in FIG. 3 - place I in FIG. one;

in FIG. 4 is a section BB in FIG. one;

in FIG. 5 is a section GG in FIG. 3;

in FIG. 6 is a view D in FIG. 5;

in FIG. 7 is a section BB of FIG. 3;

in FIG. 8 - place II in FIG. 2.

The radial sump contains a housing-tank 1, a central support-tower 2, a circular path 3, an annular tray 4, a silt scraper 5 with a drive 6, a truss 7 and an overlap 8.

The overlapping 8 of the water mirror is made of three rings — the central 9, the middle 10 and the peripheral 11. The overlap material 8 is stainless steel.

Rings 9, 10 and 11 are arranged concentrically to each other.

The central annulus 9 of the overlap is fixed and secured to the central turbine 2 of the sump. The peripheral ring 11 of the overlap is also stationary and is installed on the peripheral part of the bowl of the sump, resting on the treadmill 3 and the annular tray 4. The middle ring 9 is mounted on the water mirror and has a connection with the truss 7 of the silo scraper 5, which allows the overlap to move together with the truss 7 relative to the central 9 and peripheral 11 rings.

The overlap rings 9, 10, 11 are overlapped relative to each other. The gap between the middle ring 10 and the rings of the central 9 and peripheral 11 is sealed with a rubber seal 12 to prevent the escape of waste water vapor and odors. The seal 12 is fixed with the help of strips 13 and bolts 14.

Rings 9, 10 and 11 are prefabricated in the form of sections 15. The sections of the central 9 and peripheral 11 rings are rigidly connected to each other by bolted connections 16 (Fig. 4), and the sections of the middle overlap ring 10 have a movable loop connection 17 (Fig. 5 , 6) providing design flexibility. Design flexibility is necessary when emptying the sump, so that the overlap falls to the bottom, taking its uneven profile.

Each section 15 of the middle ring 10 of the overlap 8 is made in the form of several sealed chambers 19 to ensure positive buoyancy of the middle ring 10.

- 2 017108

To prevent snow accumulation in winter, a scraper system 20 is provided on peripheral 11 and central 9 overlapping rings 20. A row of scrapers 21 is located on the farm 7 of the silo scraper 5 with a slope towards the middle ring 10 of the overlap 8. The scrapers 21 rotate together with the farm 7 and are designed to remove snow from the central 9 and peripheral 11 overlapping rings by dropping snow onto the middle ring 10. From the middle ring 10 of overlapping 8, this snow is raked to the gap 22 between the movable and fixed overlapping rings, and then discarded camping into the water through a system of stationary scrapers 23. The fixed scrapers 23 are mounted with equal spacing at several locations along the diameter of the settler 11 to a fixed peripheral and central rings 9 overlap with a bias toward the gap between the movable and the fixed overlap rings. The scrapers 23 are arranged with a different gap from the plane of the central ring for a more uniform removal of snow.

Claims (6)

1. Overlap of the radial sump is made of composite of the Central, middle and peripheral rings, while the central ring is fixedly attached to the Central support of the sump, the peripheral ring is fixedly attached to the side of the sump, and the middle ring is mounted at the level of the water mirror and mounted on a movable farm with equipment, with the possibility of concentric rotation relative to the Central and peripheral rings. 2. The overlap according to claim 1, characterized in that the lower surface of the middle overlap ring is smooth, without voids and has constant contact with water. 3. Overlap according to claims 1, 2, characterized in that a system of scrapers is installed on the peripheral and central rings of the overlap. 4. Overlap according to claims 1, 2, 3, characterized in that the overlap rings consist of sections. 5. The overlap according to claim 4, characterized in that each section of the middle overlap ring is made in the form of independent sealed chambers, which are a box of rectangular cross section. 6. Overlap according to claims 4, 5, characterized in that the middle overlap ring has a movable loop connection of the sections, which is capable of lying on the bottom when emptying the sump, repeating its uneven profile and providing access to the equipment installed inside the sump.