EP0443205B1 - Sieve grid for the removal of solid matter from flowing fluids - Google Patents

Description

The invention relates to a sieve screen for the removal of solid components from flowing liquids, in particular wastewater, consisting of a fixed grid arranged in a supporting frame with an inclination in the direction of flow and a grid movable by external force, the bars of which engage between the bars of the fixed grid and both in the longitudinal direction of the bar and can also be moved with a component perpendicular to the plane of the stationary grid.

In the case of sieve breaking of the aforementioned type, it is necessary to move or raise the movable grating both in the longitudinal direction and perpendicular to the plane of the stationary grating and beyond it, in order to lift the solid components carried in the liquid upwards above the liquid level with the aid of several strokes to be transported to a delivery point. The sieve screens are usually inclined in the direction of flow in order to enable the sieved components to be transported. At the start of periodically performed movements, the movable grille is raised above the level of the stationary grille and additionally guided upwards in the longitudinal direction. Towards the end of the longitudinal movement, the movable grating is returned to the level of the stationary grating or somewhat below it. Then there is a reverse movement lengthways to return the grid to its starting points. The material initially lifted off the stationary grille is placed on it a little above the catch point and gradually transported upwards at an angle by repeated repetitive movements of the movable grille.

In a known embodiment, the movable grating is guided by rollers arranged in rails on its two longitudinal sides. The guide rails are arranged one above the other in two levels and are connected by switches at their front ends in the direction of the elevator.
The driving force is generated hydraulically or pneumatically. At the beginning of the longitudinal movement in the direction of the elevator, the rollers are guided through a switch to the guide rail running at a higher level. The rollers move to the end of the rail and there suddenly fall down onto the guide rail of the lower level. The weight of the grating places considerable strain on the material. For the same reason, hitting the rollers on the lower rails is associated with a large noise emission. Since the switch and the lower guide rail are within the liquid flow, coarse materials carried can block the switch. The rollers of the grating are pulled against the blocked switch by the hydraulic or pneumatic drive. The tilting of the movable grille caused by this leads to mechanical faults and damage.

In a further known arrangement for collecting and conveying solid materials located in the waste water, with a lattice construction made of movable and stationary rods according to the preamble of claims 1 and 15 corresponding US-A-4 853 116, the movable rods are in a package united and driven by a mechanism so that the rods in a suitable movement for collecting and conveying to be brought. During this movement, each point describes a closed curved path, which naturally contains at least one vertical component. For this purpose, the movable grid package with its entire weight is suspended in the upper area on eccentric discs. The eccentric discs are connected in pairs with chains and are driven together by a motor. There is no lateral guidance and support of the movable grille. The arrangement of the eccentric drive in the upper part of the movable grille and its lack of guidance and support over the entire length leads to a grille movement that is not evenly distributed over the entire grille length. Naturally, the transport movements of the movable grille depend only on the size of the eccentric discs and are very limited. The drive device also requires considerable design effort.

It is also known to provide a grid formed with fixed and movable bars with a drive in which a hydraulic cylinder is attached to a trolley above the grid structure. The trolley moves back and forth in the flow direction of the wastewater to be cleaned. The movable grid is guided on lateral guide ellipses, so that an approximately elliptical movement of the movable grid part can be achieved in connection with the adjusting movement of the hydraulic piston and the movement of the trolley. The drive construction is technically very complex and naturally prone to malfunctions for this reason.

The invention is based on the object of creating a sieve screen according to the generic term mentioned above, which is characterized by a simple construction, a trouble-free and low-noise running of the movable grille. The invention as a solution to this problem is characterized from that the movable grille is supported on each longitudinal side via levers on skids and these are mounted in guide profiles of the supporting structure, the levers being pivotable about their connecting axes with the skids by an electric drive.

The construction according to the invention is largely insensitive to mechanical disturbances. Experience has shown that coarse matter is washed away as a result of increased water supply, and the guideways cannot become blocked, since the skids are able to push the coarse matter back. The mechanical structure of the guide arrangement with the lever construction for transmitting the driving forces is simple. The movement of the movable grille is quiet. There is no sudden mechanical stress.

In a further advantageous embodiment of the invention, it is proposed to use an electric gear motor as the actuator, which reaches the force-side ends of all angle levers via rod-shaped parallel guides. With short lever ratios, a sufficient movement length can be achieved with a sufficient stroke of the grille. Another solution to the problem is described in claim 15.

Further features that advantageously shape the two subject matter of the invention are specified in the subclaims.

• Fig. 1 eine Seitenansicht eines Siebrechens mit einem Kurbeltrieb,
• Fig. 2 eine Stirnansicht des Siebrechens nach Fig. 1 im Bereich des Antriebsmotors,
• Fig. 3 eine Ansicht in Längsrichtung des Gitters nach Fig. 1 gegen das untere Ende,
• Fig. 4 die Seitenansicht eines Siebrechens mit einer Gewindespindel als Verbindungselement zwischen dem beweglichen Gitter und dem Antriebsmotor,
• Fig. 5 das obere Ende des Siebrechens nach Fig. 4 im Bereich des Antriebsmotors in größerem Maßstab,
• Fig. 6 eine Stirnansicht des Siebrechens nach Fig. 4 am oberen Ende,
• Fig. 7a-c Gitterstababschnitte zur Verdeutlichung der ausgeführten Bewegungen,
• Fig. 8 die Seitansicht eines Rechens mit einer anderen Ausführung des Antriebs,
• Fig. 9 Gitterabschnitte zur Verdeutlichung der ausführbaren Bewegungen des beweglichen Gitters gegenüber dem festen Gitter,
• Fig. 10 eine Ansicht in Längsrichtung des Siebrechens nach Fig. 8 mit Darstellung der festen Gitterstäbe und
• Fig. 11 eine Ansicht in Längsrichtung des Siebrechens nach Fig. 8 mit Darstellung des beweglichen Gitters und der Hebel.

In the drawing, several embodiments of the invention are shown schematically and explained below.
Show it:

• 1 is a side view of a screen with a crank mechanism,
• 2 shows an end view of the screen rake according to FIG. 1 in the area of the drive motor,
• 3 is a view in the longitudinal direction of the grille of FIG. 1 against the lower end,
• 4 is a side view of a screen with a threaded spindle as a connecting element between the movable grille and the drive motor,
• 5 shows the upper end of the screen in FIG. 4 in the area of the drive motor on a larger scale,
• 6 is an end view of the screen rack according to FIG. 4 at the upper end,
• 7a-c lattice bar sections to illustrate the movements performed,
• 8 is a side view of a rake with another embodiment of the drive,
• 9 grid sections to illustrate the executable movements of the movable grid relative to the fixed grid,
• Fig. 10 is a view in the longitudinal direction of the screen breaking according to Fig. 8 showing the fixed bars and
• Fig. 11 is a view in the longitudinal direction of the screen breaking according to Fig. 8, showing the movable grille and the lever.

The embodiment according to FIG. 1 shows a sieve screen 1, which is supported with vertical posts 2 of a supporting structure on the upper edges 3 of a sewer and extends with its lower ends down to the channel bottom 4.
The sieve screen consists of a fixed grating 5 made of parallel grating bars 5a, which are held together in a packet by means of rod-shaped transverse anchors. The cross anchors 6 pass through downward-facing tabs 7, so that it is possible to grasp a movable grating 8 made of rods 8a. The individual lattice bars 5a have intermediate distances in which the lattice bars 8a of the movable lattice 8 can engage.

The movable grid is on the long sides with the help of block-shaped skids 9 in profiles 10 with a U-shaped cross section guided. The lattice bars 8a of the movable lattice are also provided with lugs 11 pointing downwards and connected to one another by a bar 12 which extends transversely through the lugs. The movable grille is supported on the skids 9 by levers 13. Tabs 14 are arranged on the cross bar 12 holding the movable bars together. The levers 13 attach to them with their load-side ends. The levers in the form of triangles have two arms, since their connection points 15 with the skids 9 lie in the area of the angle. The force-side ends of the levers 13 are connected to one another by transverse rods 16 and by a central rod 18 running in the longitudinal direction of the grating, so that this results in parallel guidance. The levers 13 can be pivoted with their ends on the load side about the axes 17.

The drive motor 19 is arranged at the upper end of the grid. The output shaft of the reduction gear 20 is connected to one of the crankshaft journals 21. A connecting rod 23 extends between the crank pin 22 and the connecting rod 16 of the upper lever 13. The crank webs are designated by 24. The entire crank mechanism with the geared motor is fastened to a support plate 25 which extends transversely between the supports 2. The bearings 26 of the crank mechanism, which are connected to the plate 25, for example screwed, can be seen.

The power transmission arrangement of the embodiment according to FIGS. 1 to 3 enable the use of the motor, the direction of movement of which is uniform.

In FIG. 1, the screen rake is shown in its starting position. It rests on the channel floor 4 with its grid 5 that is stationary during use and can be pivoted up and out of the channel around the pivot pin 27 as needed, for example during maintenance work. Solid material carried in the wastewater collects on the front edges of the grids 5 and 8 in the flow direction. The bars of the movable grid 8 have the task of moving to the fixed one To transport bars of solid components that are depositing bars upwards. For this reason, the motor 19 is started up in regularly recurring periods, that is to say periodically. The crossbar 16 moves towards the engine via the connecting rod 23. As a result, the angle levers are also pivoted towards the motor. They rotate about the pivot axes 15 and thereby lift the movable bars 8a, which at the same time experience a movement component in the longitudinal direction upwards. As soon as the bars 8a go beyond the level of the stationary bars, they lift the accumulated solid components from the stationary bars and carry the solids up with them until they dip again between the stationary bars and deposit the transported material on their upper edges. During the upward movement, the skids 9 execute a sliding movement within the guide profiles 10. The levers 13 are pivoted back again by the circular movement of the crankshaft.

The movable bars 8a dip down into the gaps between the fixed bars and thereby deposit the material carried on the latter. When the engine continues to operate, the skids 9 are pushed back into their lower position. The movable lattice bars once again reach their lower starting position according to FIG. 1. The motor switches off in order to start operation again with the direction of rotation unchanged after a predetermined rest phase. In this way, the solid constituents collecting on the screen, carried along by the wastewater, are gradually carried up to the end of the stationary screen 5, from where they can fall into a collecting channel, not shown, for further removal.

In a paired rigid connection of the skids 9 by a rigid element, the connecting rod 18 for the lever 13 can be omitted, of which the lower then too simple, articulated between the skids and the movable lattice bars articulated one-armed levers shrink. This simplifies the construction of the parallel guide.

For the grid according to FIGS. 4 to 7, the same reference numerals as used in FIGS. 1 to 3 were used for identical structural parts. Thereafter, the sieve screen again consists of the fixed grid 5 with its bars 5a and the movable grid 8 with its bars 8a. The movable grille is supported on the skids 9 by levers 30. The cross bar 12 holding the movable bars together is guided through tabs 11.

With its two lateral ends 28, 29, the rod rotatably engages in the angle levers 30 attached to both sides of the sieve rake. At their force-side ends 33, 34, the angle levers 30 are connected to one another by longitudinal rods 35 and 36 and a transverse rod 37 in such a way that they form a parallel guide. The crossbar 37 carries a threaded bush 38 for receiving a threaded spindle 40, which connects the parallel guide to an electric drive motor 41. A universal joint 42 enables the inclination of the threaded spindle to be changed during operation. On their upper side, the bars 8a are provided with notches 25 in order to achieve better catchability and to prevent the detected solid components from slipping back during the upward transport. Overall, the screen rake can be pivoted about an axis of rotation 43 on the lateral supports of the supporting structure 2. It rests on the channel floor 4 with its grid 5 that is stationary during use and, if necessary, is pivoted up and out of the channel around the axis of rotation 43, for example during maintenance work. Solid material carried in the wastewater collects on the front edges in the direction of flow. Since the bars of the movable grid 8 have the task of transporting the solid components that are deposited on the fixed bars upwards, it becomes regularly recurring Periods, i.e. periodically, the drive motor 41 is put into operation. Via the threaded spindle 40, which is first turned clockwise, the cross bar 37 of the parallel guide moves towards the motor. As a result, the angle levers are also pivoted in the direction of the gear motor. They rotate about the pivot axis 32 and thereby lift the movable bars 8a, which at the same time experience a component of movement in the longitudinal direction upwards. As soon as the bars 8a go beyond the level of the stationary bars, they lift the accumulated solid components from the stationary bars and carry the solids up with them until they dip again between the stationary bars and deposit the transported material on their upper edges. During the upward movement, the skids 9 perform a sliding movement within the guide profiles 10. The upper end position of the movable lattice bars 8a is illustrated schematically with FIG. 5. When this position is reached, the drive motor switches off and then starts operating again in the opposite direction of rotation. As a result, the angle levers 30 are pivoted back again. The movable bars 8a dip down into the spaces between the fixed bars and thereby deposit the material carried on the latter. This position is illustrated in FIG. 7a. When the drive motor continues to operate with the opposite direction, ie counterclockwise in the direction of rotation, the skids 9 are retracted into their lower position. The movable lattice bars once again reach their lower starting position according to FIG. 4. The drive motor switches off in order to start operation again in a clockwise direction after a predetermined rest phase. In this way, the solid constituents collected on the screen, carried by waste water, are gradually carried up to the end of the stationary screen grid 5, from where they can fall into a collecting trough, not shown, for further removal.

The exemplary embodiment in FIGS. 8 to 11 shows a screen rake 101 which is supported by vertical posts 102 of a supporting structure on the upper edges 103 of a sewer and extends with its lower end down to the channel bottom 104. The sieve screen consists of a fixed grating 105 made of parallel grating bars 105a (see FIG. 9), which are held together in a packet by means of rod-shaped transverse anchors 106. The cross anchors 106 pass through tabs 107 pointing downward, so that a movable grating 108 made of rods 108a is possible (see FIG. 9).
The individual lattice bars 105a of the fixed lattice 105 have intermediate distances in which the lattice bars 108a of the movable lattice 108 can engage. The bars 105a and 108a are provided with serrations 125. The movable grid is guided on the long sides by means of long skids in guide profiles 110 with a U-shaped cross section. The fixed grid 105 is fixedly connected to the guide profile 110 at several points by the tabs 107. The lattice bars 108a of the movable lattice are also provided with tabs 111 pointing downwards and connected to one another by round bars 112 extending transversely through the tabs. The lateral ends 112a are rotatably supported in the levers 113a and 113b. The levers 113a and 113b are rotatably supported at their opposite ends via pins 115 on the skids. The levers 113b are also connected to the connecting rod 123 via the round rods 112. The connecting rod transmits the circular movement of the crank arm 124 as a longitudinal movement to the skids 109. The crank arm is moved by a corresponding reduction gear with an electric drive 119. The levers 113b are designed as angle levers, the ends of which on the slide runners can be supported against two stops in the form of tabs 145a and 145b. The tabs are rigidly attached to the skid 109.

At the start of the crank arm 124, the rotational movement is transmitted to the rotatable lever 113b via the connecting rod 123. in the In the first movement sequence, the levers 113b and in parallel the levers 113a rotate with an angular movement about the pivot points 115. This angular movement lifts the movable rods 108a out of the spaces between the fixed rods 105a. During the angular movement of the levers 113b, the lever parts 144 on the slide runners lie against the fixed tabs 145a. The angular movement of the levers is thereby ended and the continuing rotational movement of the crank arm 124 is now transmitted as a longitudinal movement via the connecting rod 123 to the skids 109. After 180 ° rotation of the crank arm 124, the sequence of movements becomes opposite. Due to the renewed angular movement of the levers 113b, the movable bars 108a are lowered between the fixed bars 105a. This process is ended by the stop of the angle lever 113b on the fixed tabs 145b. The further rotary movement of the crank arm 124 is now transmitted via the connecting rod 123 to the skids 109 as a downward longitudinal movement. The electric drive 119 of the crank arm 124 switches off in the starting position shown in FIG. 8.

The lattice bars of the movable lattice 108 have the task of transporting the solid components which settle on the fixed lattice bars 105a upwards. For this reason, the electric drive of the crank arm 124 is started up in periodically recurring periods — that is, periodically — as a function of an external control signal. The crank arm lifts the movable grill 108 via the connecting rod 123 and the movable levers 113a and 113b. The solid components accumulated on the grating 105 are lifted off the grating 105 and shifted upward in the longitudinal direction by the further movement sequence of the movable grating 108. This means that the accumulated solid components are transported upwards. In the upper reversal point of motion, the movable grating 108 is lowered and the solid components that have accumulated are deposited again on the stationary grating 105. The lowered, mobile Lattice bars 108a return to the starting position between the fixed lattice bars 105a. Through the periodic repetition of the movement sequence described, the accumulated solid components on the grids are transported to the discharge end, from where they fall into a collecting channel, not shown, for further removal.

The screen breaking shown in FIG. 8 can, if necessary, be pivoted up out of the channel base 104 around the pivot 127 of the fixed support 102, for example for maintenance work.
The mechanical structure of the guide arrangement with the lever construction for transmitting the driving forces is extremely simple. Impairment or blocking by coarse material of the lower lever arms 113a lying in the water is not possible, because they only perform a movement of a few angular degrees. An electric geared motor can be used as the actuator, which reaches the upper pair of levers 113b with its crank arm 124 via the connecting rod 123 for lifting and moving the grille. The required movement length for the sufficient stroke of the grille is achieved via the radius of the crank arm. By transmitting the crank movement via the connecting rod 123, the angled upper pair of levers fulfills both the function of raising and lowering the grille and the parallel displacement of the grille in the guideways 110.

Claims (20)

1. A sieve grid for the removal of solid matter from flowing liquids, more particularly sewage, comprising a fixed grid (5) disposed in a supporting structure (2) with an inclination in the direction of flow and a grid (8) which can be moved by an outside force and whose rods (8a) extend between the rods (5a) of the fixed grid and can be moved both in the longitudinal direction of the rods and also with a component perpendicular to the plane of the fixed grid, characterized in that the movable grid (8) is carried by levers (13, 30) on sliding skids (9) on each longitudinal side and the sliding skids are mounted in guide sections (10) of the supporting structure (2), the levers being pivotable with the sliding skids around their connecting pivots (15, 32) by an electric drive.

2. A sieve grid according to Claim 1, characterized in that the drive used is an electric gear motor (19, 41).

3. A sieve grid according to Claims 1 or 2, characterized in that at least two sliding skids supporting and guiding the movable grid are disposed spaced apart from one another on each longitudinal side.

4. A sieve grid according to Claim 3, characterized in that the sliding skids (9) are rigidly interconnected in pairs by a connecting rod.

5. A sieve grid according to one of Claims 1 to 4, characterized in that the driving ends of all the levers are connected to the motor via rods (16, 18, 35, 36, 37) forming a parallel guide.

6. A sieve grid according to Claim 5, characterized in that the motor (19) is connected to the parallel guide via a crank mechanism.

7. A sieve grid according to Claim 6, characterized in that the crank pin (22) of the crank mechanism is connected via a connecting rod (23) to the parallel guide (motion) of the levers.

8. A sieve grid according to one of Claims 1 to 7, characterized in that the lever arms form a substantially right-angle.

9. A sieve grid according to one of Claims 1 to 8, characterized in that the rods of the movable grid are interconnected via at least two spaced-apart rod-shaped cross members, the top cross member in the conveying direction serving to initiate the lifting and pulling forces (adjusting forces).

10. A sieve grid according to one of Claims 1, 4 or 5, characterized in that the parallel guide comprises a longitudinal rod (18) which is disposed below the grids and which connects in the longitudinal direction the driving ends of the lever arms connected via transverse rods (16).

11. A sieve grid according to one of Claims 1 to 10, characterized in that the rods of the grids are formed with notches (25).

12. A sieve grid according to one of Claims 1 to 11, characterized in that the rods of the fixed grid are smooth and the rods of the movable grid are serrated.

13. A sieve grid according to Claim 5, characterized in that the motor (41) is connected to the parallel guide via a threaded spindle (40).

14. A sieve grid according to Claims 5 or 13, characterized in that the parallel guide comprises rods (35, 36) disposed on both longitudinal sides of the movable grid to connect the driving ends of the lever arms, and a rod (37) which connects in the transverse direction the levers disposed at the top grid end and with which the threaded spindle driven by the motor engages.

15. A sieve grid for the removal of solid matter from flowing liquids, more particularly sewage, comprising a fixed grid disposed in a supporting structure with an inclination in the direction of flow and a grid which can be moved by an outside force and whose rods engage between the rods of the fixed grid and can be moved both in the longitudinal direction of the rods and also with a component perpendicular to the plane of the fixed grid, characterized in that the movable grid is borne on each longitudinal side via levers on sliding skids which are mounted in guide sections of the supporting structure, the levers are pivotable with the sliding skids around their connecting pivots by an adjusting drive, and the levers (113a, 113b) form in pairs a parallel guide together with continuous sliding skids (109) connecting the lever ends.

16. A sieve grid according to Claim 15, characterized in that the lever arms of one of the pairs of levers have prolongations (144) which engage between two stops (145a, 145b) rigidly disposed on the sliding skids (109).

17. A sieve grid according to Claim 15 or 16, characterized in that the adjusting drive (119) is connected to the parallel guide via a crank mechanism (124) and a connecting rod (123).

18. A sieve grid according to one of Claims 15 to 17, characterized in that the rods (108a) of the movable grid (108) are interconnected via at least two spaced-apart rod-shaped cross members (112) which serve to initiate the lifting and pulling forces (adjusting forces).

19. A sieve grid according to one of Claims 15 to 18, characterized in that the arrangement of the levers (113a, 113b) is devised for performing both an angular movement and also a longitudinal displacement of the movable grid.

20. A sieve grid according to one of Claims 15 to 19, characterized in that for maintenance or repair purposes the complete sieve grid can be pivoted out of the flow of sewage around the pivot pin (127) of the fixed support (102).

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