EP2038488B1 - Screening grid on an overflow spillway of a rainwater relief system - Google Patents

Abstract

In a rotary brush screen at an overflow sill of a rainwater relief system, comprising screen bars extending transverse to the overflow sill and strippers engaging in the screen bars in a comb-like manner, the strippers are put into a curvilinearly extending, circling movement via a crank drive in accordance with the invention by means of an actuating lever in cooperation with a stationary support bearing, due to which circling movement the strippers are guided from above into the spaces between the screen bars and out again at the bottom of the overflow sill. The risk of the discharge of solids into the waters as a result of a mechanical influence on the solids during the stripping operation is reduced thereby and the operational safety is increased.

Description

The invention relates to a screen rake at an overflow threshold of a rain relief system referred to in the preamble of claim 1. Art.

Screening rakes of this type are usually used at overflow thresholds of rain relief structures of the sewer system to prevent the precipitation of the discharge of entrained solids in the sewage, such as feces lumps, toilet paper, toiletries o. Ä., In the waters. The solids retained on the screen bars are thereby to be returned to the wastewater stream which continues to the sewage treatment plant.

At the DE 44 38 716 A1 and the GB 1 174 915 A screen rakes of the type mentioned are known. GB 1,174,915 shows a screen rake according to the preamble of claim 1.

The from the DE 44 38 716 A1 known screen rakes are characterized by a simple, robust and compact design, the use of which is well suited especially in confined spaces and thus for retrofitting.

They consist of a arranged at the overflow threshold computing grid with transverse to the overflow threshold and the overflow threshold directed upwards rake bars, ropes o. The like., In the interstices of a crank drive, comb-like scrapers are pivoted about a lever mechanism back and forth. The adhering to the rake bars solids are transported by the scrapers at each pivoting movement to the end portions of the computing bars. There they should detach themselves from the scrapers on the rake bars and then sink into the sewage stream flowing to the sewage treatment plant.

However, this gives rise to the problem that in particular the solids stripped off by the scrapers upwards and against the outflow flow and thereby formed into lumps, are immediately washed back against the rake bars after the turning point of the swiveling movement with the suction of the overflow flow.

By then pressed by the flow pressure of the overflow flow into the interstices of the computing bars clumped solids, the stripping resistance increases at the rake bars. With increasing operating time and inevitably increasing accumulations of solids, the stripping resistance can become so great that the function of the crushing stops.

In addition, it is disadvantageous that the stripped solids by the v. G. Problem inevitably be detected several times by a stripping and so crushed due to the mechanical effects of the scrapers on the rake bars and under the pressure of the overflow, crushed and thus reach in divided form in the waters.

In particular, when solids made of plastic material, such as hygiene articles, wrap around the scrapers and / or around the rake bars, scissors-like pivoting of the scrapers into the interstices of the rake bars, the risk of jamming on the rake bars is particularly large.

A further disadvantage is that at the reversal points of the scraper pivotal movement complete leaching of the clumped solids from the scrapers is not possible. As a result, form on the stripper clogging, which no longer detach themselves and thereby also lead to increased frictional resistance to the rake bars, cause the malfunction and / or have an increased maintenance costs result.

The invention is therefore an object of the invention to provide a screen rake of the type mentioned, in which the risk of solids discharge in the

Waters are reduced due to mechanical effects on the solids during stripping and the reliability is increased.

The solution of this task is carried out according to the characterizing features of claim 1; particular embodiments of the invention are the subject of the characterizing features in the subclaims.

The advantage of the crushing of the invention consists primarily in the avoidance of o. G. Disadvantage.

During the stripping process, the solids retained on the screen bars are scraped off via the kinematics of the stripper which rotate in accordance with the invention exclusively via a downward movement and thereby in a gentle manner.

To replace the accumulation of solids from the scrapers in the lower area of the rake bars, a directed and to the discharge side almost linear lead out the scraper with the overflow flow from the interstices of the rake bars is effected. As a result, the scrapers on the rake bars are completely and gently freed from the solids after each stripping operation, without any scissor-like crushing of the solids or jamming of the scrapers on the rake bars.

By Abstreiferkinematik invention the vg detachment of solids from the scrapers is also possible below the overflow threshold level. The detached there solids can be collected for example in a foreclosed against the suction of the overflow collecting trough and returned to the end of the discharge event in the flow to the sewage treatment plant.

In the case of the screen rake according to the invention, there is the particular advantage that, in the event of a blockage of the scrapers on the rake bars, for example as a result of an extreme accumulation of solids or due to clamped-on solid parts, this can be eliminated on its own.

Occurs when combing the rake bars on a blockage as described above, then the scrapers remain hanging on the blockade, at the same time the actuating lever lifts by the still undisturbed rotating crank drive from the support bearing and is inevitably moved back in the direction of the crank drive.

If this movement sequence, the scraper comb is pulled away from the blockage, then the Abstreiferkamm falls over its own weight abruptly down until the associated actuating lever again impinges on the support bearing. About the thus generated force of the abruptly falling scraper comb the causative for the blockage solids from the interstices of the rake bars out and pushed back into the inlet flow of the overflow water, whereby the blockade is eliminated.

During the stripping process, the overflow stream directed at the scrapers or at their carrier element acts as a driving force on the crank drive and thus offers spatial and structural advantages, in particular in a waterwheel drive, because the waterwheel can be made more compact or smaller by means of this force support.

Further features, details and advantages of the invention will be explained in more detail with reference to exemplary embodiments illustrated in the drawings.

Figur 1:

einen Vertikalschnitt durch die Regenentlastungsanlage und den Siebrechen quer zur Überlaufschwelle,

Figur 2:

eine Draufsicht auf den Siebrechen gemäß Fig. 1 als Horizontalschnitt durch die Regenentlastungsanlage,

Figur 3:

eine vergrößerte Darstellung des Siebrechens in der Draufsicht,

Figur 4:

eine vergrößerte Darstellung des Siebrechens im Vertikalschnitt mit in den Zwischenräumen der Rechenstäbe geführten Abstreifern,

Figur 5:

eine vergrößerte Darstellung des Siebrechens im Vertikalschnitt mit den außerhalb der Rechenstäbe geführten Abstreifern,

Figur 6:

Detail eines Abstreifers mit vergrößerter Kontur in der Vertikal-Ansicht,

Figur 7:

Draufsicht zu Fig. 6,

Figur 8:

eine Darstellung entsprechend Figur 4 einer zweiten Ausführungsform,

Figur 9:

eine Darstellung entsprechend der Figur 3 einer zweiten Ausführungsform, und

Figur 10:

eine Darstellung entsprechend der Figur 5 einer zweiten Ausführungsform.

Show it:

FIG. 1:

a vertical section through the rain relief system and the screen rake across the overflow threshold,

FIG. 2:

a plan view of the screen according to Fig. 1 as a horizontal section through the rain relief system,

FIG. 3:

an enlarged view of the Siebrechens in plan view,

FIG. 4:

an enlarged view of the Siebrechens in vertical section with guided in the interstices of the computing bars scrapers,

FIG. 5:

an enlarged view of the Siebrechens in vertical section with the outside of the computing bars guided scrapers,

FIG. 6:

Detail of a scraper with enlarged contour in the vertical view,

FIG. 7:

Top view to Fig. 6 .

FIG. 8:

a representation accordingly FIG. 4 a second embodiment,

FIG. 9:

a representation according to the FIG. 3 a second embodiment, and

FIG. 10:

a representation according to the FIG. 5 a second embodiment.

The drawings show a screen rake 1, which is arranged at an overflow threshold 21 of a rain relief system 20. The rain relief system 20 has an inlet channel 22, an outlet channel 23 and a discharge channel 24 leading to the receiving water.

During a precipitation event, the water level in the relief system 20 rises between inlet channel 22 and outlet channel 23. The amounts of water that can not be absorbed by the sewage treatment plant are transferred via the overflow threshold 21 into a body of water knocked off and flow through the arranged at the overflow threshold 21 Siebrechen. 1

The screen rake 1, which is preferably arranged in the upper region of the overflow threshold 21, consists of a multiplicity of rake bars 2 or ropes which are directed transversely to the overflow threshold 21 and from the rollover threshold 21 and up to which the solids entrained in the overflow water are retained when flowing through the rake bars 2.

Before the direction of the discharge channel 24 side of the overflow threshold 21 comb-like juxtaposed scrapers 4 are arranged on a support member 5 to which an actuating lever 6 is attached. The other end of the actuating lever 6 is pivotally connected to a crank drive 8, via which the scrapers 4 mesh during operation in the interstices 3 of the computing bars 2.

About a arranged in the region of the actuating lever 6, stationary support bearing 7, the actuating lever 6 is contacted by its own weight or the scraper 4 with the support bearing 7.

When the crank drive 8 is rotated, the articulated actuating lever 6 is moved in the horizontal direction to and fro in the stationary, preferably roller-shaped, support bearing 7. At the same time the actuating lever 6 is pivoted in the vertical direction, whereby the connected to the scrapers 4 end of the actuating lever 6 is set in a curved linear, circular motion.

In this case, the scrapers 4 in the upper region of the computing bars 2 in opposite directions to the flow direction in the interstices 3 in and out in the lower region of the computing bars 2 in the flow direction again.

For a better overview, see Fig. 4 the kinematics of the Siebrechens 1 in the phase with the guided in the interstices 3 of the computing bars 2 scrapers. 4 shown. In Fig. 5 the kinematics of the Siebrechens 1 in the phase with the outside of the computing bars 2 moving scrapers 4 is shown.

The individual components of the Siebrechens 1, such as crank drive 8, operating lever 6, support bearing 7, computing bars 2, etc. are exemplified by a frame-shaped bracket 19 which is fixed to the wall surfaces of the rain relief system 20, connected to each other or stored in this. Of course, the components such as the operating lever 6 and the support bearing 7 are preferably arranged in pairs for design reasons.

In Fig.1 to Fig.5 According to the exemplary embodiment, a foreign energy-free operation of the Siebrechens 1 by means of a water wheel 9 is shown. About a belt or chain drive 25, the rotational movement of a water wheel 9 is transmitted to the crank drive 8; a power transmission by means of electric motor to the crank drive 8 is also possible.

In the kinematics of the wiper 4 according to the invention, the touching contour of the actuating lever 6 and / or support bearing 7 is preferably formed as a control curve 18, through which the crank drive 8 toward almost linear and obliquely upward movement of the scraper 4 when removing the scraper 4 from the gaps 3 of the computing bars 2 is effected.

To accommodate the stripped to the rollover threshold 21 solids in the crown area at the overflow threshold 21 preferably a drip pan 10 is provided, which is closed laterally and from below in the operating case. Due to the inertia of the water, the solids stripped off there remain in the sealed tub liquid and are not sucked in with the overflow flow to the screen bars 2. The solids uptake in the collecting trough 10 is particularly advantageous when the detachment process of the solids from the wipers 4 in the interior of the collecting trough 10 and, because of the overflow, below the threshold upper edge is completed.

A float-controlled hinged bottom 11 on the underside of the drip pan 10 releases the collected solids into the wastewater stream leading to the sewage treatment plant after the end of a discharge event.

In the longitudinal direction of the overflow threshold 21 is guided over the actuating lever 6 guided support member 5 and thus also the scrapers 4, by design a slightly divergent sideways movement. In order to prevent that even with a sideways movement of only a few millimeters, the scrapers 4 encounter when engaging in the interstices 3 against the computing bars 2 or intervene in adjacent spaces 3, in which the mechanism could block, the invention provides in a further embodiment in that, distributed over the length of the support element 5, a selected number of strippers 4a are arranged, which have a larger contour compared to the remaining strippers 4.

For this purpose, guide elements 13 are arranged in an area where the scrapers 4, 4a leading to the screen bars 2 are to again engage in the interspaces 3 of the screen bars 2, for the scrapers 4a with the larger contour.

The preferably formed from a sheet metal strip guide elements 13 are seen in flow view to the overflow, provided to the enlarged scrapers 4a out with funnel-shaped guide slots 15, in which engage the contours of the scraper 4a and are thus aligned in operation in their sideways movement inevitably.

If, for example, a piece of wood entrained in the wastewater or the like clamps between the rake bars 2 in such a way that a further wiper movement is no longer possible, then the wipers 4 can be activated by automatically lifting the operating lever via the loose connection between actuating lever 6 and support bearing 7 according to the invention 6 of the support bearing 7, their function, albeit in a limited form, to the Disturbance continue to maintain, without causing the entire device is disabled and possibly damaged.

Extremely high quantities of overflow water caused by rare heavy rain events can be discharged to the discharge channel 24 via the upper end of the computing bars 2 in the form of an emergency overflow. Thus, the operating lever 6 and the scrapers 4 are not torn up by such amounts of water and damaged is conceivable that arranged by a on the operating lever 6 or the support bearing 7, here not shown securing bracket, a turnover or an extreme lifting of the operating lever 6 from Support bearing 7 is prevented.

In the FIGS. 8 to 10 a further exemplary embodiment of a foreign energy-free operation of the Siebrechens 1 by means of a water wheel 9 is shown. This embodiment substantially corresponds to that of FIGS. 1 to 5 ,

Claims (10)

1. A rotary brush screen (1) at an overflow sill (21) of a rainwater relief system (20), comprising
   screen bars (2) which extend transverse to the overflow sill (21),
   strippers (4) which can be guided in the spaces (3) of the screen bars (2),
   a crank drive (8), and
   a lever mechanism which is motionally connected with the crank drive (8) and includes an actuating lever (6) and a stationary support bearing (7),
   wherein the strippers (4) are actuated by the crank drive via the lever mechanism, and wherein the actuating lever (6) at one end is pivotally connected with the crank drive (8), at the other end carries the strippers (4), and cooperates with the support bearing (7) such that when the crank drive (8) rotates, the strippers (4) are put into a circling movement extending vertical and parallel to the screen bars (2),
   characterized in that
   during the circling movement the strippers (4) are guided into the spaces (3) between the screen bars (2) in the upper region thereof opposite to the flow direction and in the lower region of the screen bars (2) are guided out of the spaces (3) between the same in flow direction.
2. The rotary brush screen according to claim 1, characterized in that the actuating lever (6) is connected with the support bearing (7) loosely and only by the own weight of the actuating lever (6) and/or that of the strippers (4), and on the stationary support bearing (7) it is moved to and fro in horizontal direction and at the same time swivelling in vertical direction, whereby the end of the actuating lever (6) connected with the strippers (4) is put into a curvilinearly extending, circling movement.
3. The rotary brush screen according to claim 1, characterized in that the contacting contour between actuating lever (6) and support bearing (7) constitutes a control cam.
4. The rotary brush screen according to any one of claims 1 to 4, characterized in that the detachment of the solids from the strippers (4) is effected below the upper edge of the overflow sill (21).
5. The rotary brush screen according to any one of claims 1 to 4, characterized in that the strippers (4) are again guided out of the spaces (3) between the screen bars (2) almost linearly.
6. The rotary brush screen according to any one of claims 1 to 5, characterized in that for collecting the stripped solids a collecting pan (10) is arranged at the overflow sill (21).
7. The rotary brush screen according to any one of claims 1 to 6, characterized in that distributed on the carrier element (5) a certain number of strippers (4a) is arranged, which have a greater contour than the remaining strippers (4).
8. The rotary brush screen according to claim 7, characterized in that for aligning the strippers (4) guide elements (13) are provided for the strippers (4a) with the enlarged contour.
9. The rotary brush screen according to claim 8, characterized in that the guide elements (13) are arranged in a region where the strippers (4, 4a) engage in the spaces (3) between the screen bars (2).
10. The rotary brush screen according to any one of claims 8 or 9, characterized in that the guide elements (13) have a guiding slot (15) extending in a funnel-shaped manner to the spaces (3) between the screen bars (2).

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