RU2442635C2 - Device for mechanical removal of the sediment from the radial-flow settlement tank - Google Patents

Abstract

FIELD: waste-water treatment technology.

SUBSTANCE: invention relates to waste-water treatment technology in radial-flow settlement tanks by means of removal of suspended particles of insoluble matters from the waste water sedimenting on the settlement tank bottom; the device comprises the active carrier gear and the group of principle scrapers which have the kinematical connection to the active carrier drive and to one another and collectively form the blade on the bottom of the settlement tank; the device is provided with a group of additional scrapers distributed along the blade and kinematically connected to the active carrier drive, each of them is installed in front of the blade at the distance not less than the height of the principle scraper.

EFFECT: provision of the efficient treatment of the bottom of radial-flow settlement tanks with the minimal energy consumption.

1 cl, 5 dwg

Description

The present invention relates to a technology for wastewater treatment in radial sumps by removing from the effluent suspended particles of insoluble substances that precipitate at the bottom of the sump in the form of sediment. This invention may find application in radial sumps at aeration stations for drinking and wastewater and other industrial wastewater treatment plants.

A similar device is known for mechanical removal of sludge from a radial sump (see RF certificate for utility model No. 30613, 07/10/2003), designed to be installed on a radial sump to rake the sludge into the silt pit at the bottom of the radial sump, containing an active carrier ( a bridge equipped with a drive), on which a tool is mounted that makes complex movement along the bottom of the radial sump with a portable movement in a circle around the center of the radial sump and with periodic relative motion m along an arc of a circle from the bottom border to the silt pit, while the sediment is removed from the bottom in stages in separate strips overlapping one another in succession. As a result of repeated movements of the tool in relative motion along the strips overlapping one after another, simultaneously with the removal of sludge, the bottom is cleaned, which is the advantage of this equipment, since the bottom cleaning prevents the formation of local zones of adhering sludge on it, which compacts, rots over time and floats to the surface, reducing the quality of water treatment. The specified known device for mechanical removal of sediment returns the radial sump to its original state within one cycle of the portable movement of the tool.

Known for another similar device for the mechanical removal of sediment from a radial sump (see RF patent No. 60390, Bull. No. 3, 01/27/2007). This device is also intended for installation on a radial sump with the aim of raking sediment into the sludge pit at the bottom of the radial sump. It contains an active carrier (see above), kinematically connected with an instrument that performs complex movement along the bottom of the radial settler with a portable movement around the center of the radial settler and with continuous relative movement around the circumference between the bottom boundary and the silt pit through the use of corresponding individual drives. In this case, the tool removes sediment into the sludge pit in stages in separate strips, overlapping one another in succession. Compared with the first analogue in this device, the total length of tool movements in its relative movement along the bottom doubles. Therefore, the likelihood that the radial sump will be returned to its original state during one cycle of portable rotational movement of the tool increases significantly.

Thus, in both known similar devices, high sediment removal efficiency is achieved by repeatedly repeating the movements of the raking tool along the bottom during the cycle, however, the amount of energy corresponding to the total length of these movements is spent on making these movements.

A device for the mechanical removal of sediment from a radial sump (see USSR author's certificate No. 464536, BI No. 11, 03/25/1975), containing an active carrier, that is, a bridge equipped with a drive, as a surface part and an underwater part in the form of a truss, connected to the drive axle, and a working tool, which is a group of scrapers, in which the scrapers are arranged in a row in a spiral line and connected by adjacent edges to each other by means of hinges, each scraper has a tie rod fixed to it, pivotally connected with the farm.

The task to be solved by the device according to USSR author's certificate No. 464536 is the formation of a prism of drawing of the removed sediment and at the same time giving it movement in the direction of the silt pit, which is achieved by arranging the scrapers along a line close to the spiral, resulting in a dump from the scrapers.

The advantage of this known device, in contrast to the aforementioned analogues, is its low power consumption due to the minimum length of disposable scrapers and raked sediment along the bottom during a cycle of movement.

However, one-time movement of the scrapers along the bottom during a cycle, performed invariably in one direction, leads to the fact that part of the sediment is smeared with a thin layer on the bottom, compacted and adhered to the bottom surface. As already noted, such a layer rots and after some time, under the influence of gas bubbles formed during decay, it floats to the surface, which affects the quality of wastewater treatment.

This well-known technical solution is selected as a prototype, so it has the largest number of essential features in common with the claimed technical solution.

The objective of the present invention is to eliminate the inherent disadvantage of the known device due to the introduction of new scraper elements into the working tool, which would exert a preliminary mechanical effect on the monolithic structure of caked sediment in order to weaken the adhesion of this sediment to the bottom surface. At the same time, the main advantage of the prototype should be preserved, namely, the low consumption of energy spent on the movement of silt sediment into the pit.

The problem is solved as follows. A known device for the mechanical removal of sediment from a radial sump, containing an active carrier and a group of main scrapers that have a kinematic connection with both the active carrier and with each other, forming together at the bottom of the radial sump, at least one dump, ACCORDING to the present invention is provided a group of additional scrapers distributed along the said blade and kinematically connected with the active carrier, each of which is installed in front of the blade at a distance equal to at least those primary scraper.

Such a new technical solution, while retaining the advantages of the prototype, with the totality of its essential features, ensures the cleaning of the bottom of the radial settler during each raking cycle of the removed sediment.

The inventive combination of essential features is not known from the prior art. Therefore, the proposed device can be recognized as new.

The inventive device for the mechanical removal of sludge from a radial sump meets the patentability criterion of "inventive step", since the proposed technical solution for a specialist does not explicitly follow from the prior art.

The essence of the claimed device is illustrated by drawings, where:

figure 1 - diagram of the relative position of the main and additional scrapers;

figure 2 - diagram of the device with additional scrapers deployed in the direction of the silt pit of the radial sump with a central silt pit;

figure 3 - diagram of the device with additional scrapers deployed in the direction opposite to the silt pit of the radial sump with a central silt pit;

4 is a diagram of a device with additional scrapers deployed in the direction of the silt pit of the radial sump with an annular silt pit;

5 is a diagram of a device with additional scrapers deployed in the direction opposite to the silt pit of the radial sump with an annular silt pit.

Additionally, FIGS. 1-5 indicate the direction of movement of the equipment (solid bold arrow) and FIG. 1 shows the direction of movement of the raked sludge relative to the scrapers (dash-dot line).

The device for mechanical removal of sediment from the radial sump contains an active carrier (1) pivotally connected to a fixed support (2) with the possibility of rotation around it, as well as main scrapers (3) and additional scrapers (4). The drive of the active carrier (1) can be a movable support (5), which can be made in the form of a drive trolley, that is, have at least one wheel equipped with a drive. The drive of the carrier may be separate from the movable support and is made, for example, in the form of an engine with a gearbox, which is connected with a chain, gear or pinion gear located along the perimeter of the radial sump; the drive can also be located on a fixed support (2) and directly drive the carrier (1), while the carrier structure itself can be located, at least partially, under water. Thus, the active carrier (1) - this carrier, one way or another equipped with a drive. As for the movable support (5), it is not an obligatory element of the equipment and may be absent, for example, on small diameter radial sumps, when it is enough to have a cantilever active carrier (1) with a fixed support (2), driven by the support ( 2) driven. The main scrapers (3) have a kinematic connection between themselves and with the active carrier (1). In the aggregate, the main scrapers (3) are interconnected in the form of at least one blade. The kinematic connection of the main scrapers (3) with each other can be performed by hinges (6). Additional scrapers (4) are distributed along the main scrapers (3). Each of the additional scrapers (4) has a kinematic connection also with the active carrier (1) and is installed in front of the corresponding dump at a distance equal to at least the height h of the main scrapers (3).

The proposed device mounted on a radial sump works as follows. Wastewater entering the treatment is fed in a continuous stream into the bowl of the radial settler through the central inlet pipe (7). While the wastewater is in the radial sump bowl, they are treated both due to the physical processes of the formation of agitated particles on the bottom (8) of the sump and on the chemical-biological processes of formation of various organic coagulants, which also sink to the bottom (8) of the sump, dragging more fine particles. Thus, a sludge layer is formed at the bottom (8) of the sump. The active carrier (1), relying in the case under consideration on a movable support (5) moving along the board (9) of the sump bowl, moves the main scrapers (3) and additional scrapers (4) along the bottom (8). At the same time, a drawing prism with a leg B is formed from the sediment in front of the blade, guided into the silt pit (10) due to the shape of the main scrapers (3) in the plan.

The additional scrapers installed in front of the dump (4) when moving them along the bottom (8) are inserted at an acute angle into the mass of the sediment to be removed, they are divided into parts and cut from the bottom surface, shifting each part of the massif individually in a direction that intersects with the direction of movement of the main scrapers (3). Due to this, the effect of improving the quality of bottom cleaning is achieved, since the mechanical effect on the removed sludge, preceding the movement of the dump into the sludge pit, prevents the sediment from sticking to the bottom. The direction of the indicated shift depends on which side relative to the silt pit additional scrapers are deployed (4). The effect of improving the quality of cleaning the bottom, of course, is achieved only if the size and location of the additional scrapers (4) provide them with the passage along the entire surface of the bottom of the radial sump. The connection of the main scrapers (3) with hinges (6) allows the main scrapers (3) to rotate with respect to each other in a vertical plane and in the best way fit to the bottom irregularities (8), which also improves the quality of bottom cleaning (8). It should also be noted that the presence of hinges (6) is optional; An improvement in the adjoining of the sump bowl to the bottom (8) can be achieved, for example, by selecting the appropriate flexibility of the blade as a whole or by setting certain requirements for bottom irregularities (8) to ensure compatibility between the equipment and the sump.

Based on the experiments and conditions laid down in the calculation of sediment raking forces, the shape of the section prism is a figure close to a right triangle with hypotenuse located at an angle of 45 ° to the bottom surface of the sump, and the leg of this triangle does not exceed the height of the main scraper ( see, for example, V. I. Morozova’s dissertation “Research and development of rational equipment for removing sludge from radial settlers”, L., 1979).

Thus, the minimum clearance between the blade and additional scrapers (4), sufficient for the prism of the drawing along the blade to pass, must be at least one height h of the main scrapers (3). Due to the fact that the drawing prism in cross section is an isosceles right triangle, the leg of which increases as the material of the raked sediment approaches the silt pit (10) in its relative movement along the blade and reaches size B, the height h of the main scrapers (3) should be greater than B and, accordingly, the distance between the additional scrapers (4) and the main scrapers (3) must be at least h. This condition will ensure unhindered passage of the drawing prism. Specific values of B and h are calculated from the load on the radial sump, expressed in the maximum amount of sediment falling to the bottom of the sump in mm / day. For example, the calculation of the equipment of a particular 54-meter primary radial sedimentation tank with a precipitation of up to 270 mm / day shows that B will not exceed 160 mm and the height of the main scrapers (3) 250 mm is sufficient with a margin. Accordingly, at the same distance from the main scrapers (3), additional scrapers (4) can also be located.

A feature of the proposed device is also that when turning the additional scrapers (4) in the direction opposite to the silt pit (10), the effect of cleaning the bottom is enhanced by a sharper change in the direction of movement of the sludge, moved first by additional scrapers (4), and then by the main scrapers (3).

At the same time, an additional effect of compensating for the radial force acting on the blade resulting from the opposite direction of the radial components of the reactive forces acting on the main (3) and additional (4) scrapers is achieved.

Thus, the proposed device for the mechanical removal of sludge from the radial sump provides effective cleaning of the bottom of the radial sump with minimal energy consumption.

Claims (1)

A device for the mechanical removal of sediment from a radial sump, containing an active carrier and a group of main scrapers, which have a kinematic connection with both the active carrier and with each other, forming together at the bottom of the radial sump, at least one dump, characterized in that the device equipped with a group of additional scrapers distributed along the said blade and kinematically connected with the active carrier, each of which is installed in front of the blade at a distance equal to at least the height of the main of the scraper.

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