EP2188064B1 - Eccentric screen element for disk screens - Google Patents

Abstract

The invention relates to a star body for a star disk screen and a star disk screen comprising a plurality of rotatable axes oriented parallel to one another. At least one star body (10) provided with star fingers (16, 24, 26) is disposed on at least one of said axes. In order to vary the screen hole size when the star disk screen is in operation, said star body is designed or oriented eccentrically to the rotational axis (15) thereof.

Description

The invention relates to a sieve element, in particular sieve discs of disc sieves and a disc screen with a number of mutually parallel rotatable axes for separating supplied material, in particular for separating bulk materials, such as compost, bark mulch, rubble and the like organic or inorganic materials.

Background and state of the art

Various screen systems are known in the prior art, which are used for the presorting of bulk materials, in particular recyclable or reprocessed bulk materials application. Such a screen system, also referred to as a screen screen, is for example in DE 93 09 872 U1 as well as in the EP 1 088 599 B1 described.

Such screening systems have parallel waves to be driven synchronously or asynchronously, the groups of sieve elements, such as screen stars, which are axially offset relative to the gap, are provided. Such screen stars are usually made of elastic material and have elastically yielding sickle-shaped, extending in the radial direction to the shaft fingers or star fingers. The fingers are aligned in the direction of rotation nacheilend and are accordingly designed as Abstreifzinken. The respective distances between adjacent, rotatably mounted screen stars and Siebsternwalzen are to be sorted each good.

The EP 1 088 599 B1 describes rotary screen elements, which have reinforcing parts on selected star fingers, which constantly travel during the screening process over the collar of adjacent rotary screen elements which is axially widened in relation to the star fingers. By this measure, neither dirt nor foreign matter can accumulate on the collar of the sieve elements, so that during the screening process, a permanent cleaning of the axial spaces between the sieve elements takes place.

Although so trained rotary screen elements with radially projecting at the star fingers cleaning elements allow effective and continuous cleaning of the star wheel screen during operation. However, the use of such radially projecting cleaning elements also requires the application of a very large torque on the axis, so that both the energy consumption and the material wear, in particular the cleaning elements, is quite high.

In addition, the cleaning elements are designed such that they almost completely fill the space between the star discs, so that in these star disc gaps the sorted to be sorted with the Sternscheibensieb Good and can be squeezed, which increases the mechanical stress on the screen significantly.

A generic sieve is from the AU 259 866 A known. The sieve element has crescent-shaped star fingers, which are arranged distributed around the axis of rotation of the sieve element. The outer contour of the screen element is in one Projection formed perpendicular to the axis of rotation eccentric to the axis of rotation.

From the GB 2 268 867 A is another sieve with sickle-shaped star fingers known. The star fingers are arranged distributed with the exception of a single star finger with substantially the same radial distance around the axis of rotation of Siebelements. Only the one screen element has a larger radial distance.

Another sieve is from the EP 0 136 442 A1 known. This results in a screen element whose outer contour is formed in a projection eccentric to the axis of rotation.

A similar sieve element is also from the US 2,150,717A known.

Another sieve is from the FR 1 240 250 A known. This sieve element has an outer contour which is arranged concentrically to the axis of rotation of the sieve element. In this case, a reinforcing element is provided on a star finger, which projects beyond the end of the star finger to the outside.

Another turn screen element is from the WO 94/20227 A1 known.

task

The present invention is therefore an object of the invention to provide novel and improved screening elements, as well as an improved disc screen available, in which lower mechanical stresses on the screen elements occur and which is less prone to foil, fiber or rope-like objects in the to capture separating bulk material. In addition to be provided by the invention, a higher screening performance and an adaptability to already existing Scheibensiebsysteme available.

Invention and advantageous effects

The object underlying the invention is achieved by means of a screen element according to claim 1 and a disc screen according to claim 10. Further advantageous embodiments of the invention are specified in the respective subclaims.

The screening element according to the invention is intended for use in a disc screen having a number of parallel rotatable shafts or shafts. On these axes, individual sieve elements are arranged so as to be non-rotatable with respect to one another in a gap, so that sieve elements of adjacent shafts intermesh with one another during rotation operation.

The screen element may have a polygonal, elliptical but also polygonal, such as four-, six- or octagonal outer contour, wherein radially outwardly extending portions of the screen element immersed in axial interstices of screen elements adjacent arranged waves.

The sieve element according to the invention is characterized in that it is formed or mounted in the plane perpendicular to the axis of rotation eccentric to the axis of rotation, so that during operation of the Scheibensiebs, ie upon rotation of the sieve around its axis of rotation, the sieve size of the Scheibensiebs.

The screen hole size here is to be understood as the radial distance between an outer contour section of a screen element to the hub or to the collar of one or more screen elements mounted on an adjacent axle or shaft.

The required eccentricity of Siebelements can already be done by an eccentric, that is off-center storage of Siebelements on the associated axis of rotation. In operation, such a sieve performs a kind of tumbling motion on the one hand between the adjacent extending, also equipped with sieve elements axes and the other perpendicular thereto. As a result, the material to be screened in particular in the vertical direction, that is moved and loosened substantially perpendicular to the plane of the rotatable axes. Such a movement and loosening of the Siebguts as well as in the operation of the Scheibensiebs continuously varying Sieblochgröße lead to a higher screening performance.

An eccentric design or arrangement in the sense of the invention means an asymmetrical geometry or off-center mounting of the sieve element with respect to the axis of rotation. The required eccentricity of the Siebelements can in different ways, such as by an off-center or eccentric storage of Siebelements and / or be achieved by a correspondingly asymmetrical geometric design, in particular the outer contour of the screen element.

According to a first advantageous embodiment of the invention it is provided that on the sieve element in the axial direction relative to the outer contour widened collar or a widened hub of the sieve is formed concentrically or radially symmetrically to the axis of rotation. The broadened in the axial direction collar passes during operation of the disc screen at least temporarily with the outer contour of arranged on adjacent waves sieve elements at least almost or even directly in an investment position.

According to a development it is provided that the eccentric training or storage is universally applicable to a variety of different screen elements, in particular on screen plates with different outer contours. Thus, star-shaped disks provided with sickle-shaped star fingers are like four-, six-, eight- or the like polygonal contours of screen disks as well as polygonal, elliptical or rounded toothings, outer contours of screen disks within the scope of the invention.

It is further provided that edges or end sections of a screen element which lie in the radial direction outside are spaced apart from the axis of rotation of the screen element differently from the axis of rotation.

The individual outer end sections may themselves have a different extent in the radial direction.

Alternatively, an asymmetry or a corresponding eccentricity can also be provided between the axially widened collar and the projection of a region of the sieve element forming the outer contour.

According to a particularly advantageous embodiment of the invention, it is provided that the outer contour of the sieve element has a plurality of sickle-like radial fingers extending in the radial direction, so that the sieve element is designed as a so-called star body or star disc.

It is particularly provided that the free ends of the star fingers are spaced differently far from the axis of rotation of the star body, resulting in a rotational symmetry deviating outer contour of the star body or the Siebelements with respect to its suspension or storage on the rotatable axis.

It is further provided that the radially outer end portions of adjacent star fingers in the circumferential direction of the star body have a continuously changing distance from the axis of rotation. In this way it can be achieved that the Sieblochgröße the Scheibensiebs in operation not abruptly, but continuously, according to the radial outer contour of the star body changes. Accordingly, no jerky, but uniform rising and falling movement are introduced into the screening system.

Furthermore, an eccentric formation of the gap between the concentric collar and the actual Star finger approach provided. The free ends of the star fingers can then come to rest even eccentrically to the axis of rotation of the star body, even if the star fingers themselves have an identical radial extent.

Thus, the throats provided between the individual star fingers can come to lie far different from the widened collar of the star body. In extreme cases, such a throat or the associated star finger approach coincides with the axially widened collar of the star body.

This point opposite, that is, by 180 ° in the circumferential direction leading or lagging, then preferably is that star finger with the largest radial extent in relation to the axis of rotation.

According to a further preferred embodiment of the invention it is provided that the radially outer end portions of the individual star fingers lie on an imaginary circle whose center is radially offset from the axis of rotation of the star body. In this embodiment, the star body has a radially symmetrical outer contour. Only through its eccentric bearing on the axis of rotation does it perform a tumbling motion during operation of the star wheel screen, which has a loosening and throughput-promoting effect on the screenings.

According to a further aspect of the invention, a cleaning element is arranged on at least the radially outer portion of the screen element whose free end has the greatest radial distance from the axis of rotation. This, also as reinforcing part trainees cleaning element has typically has a greater rigidity than the screen element, which is preferably made of elastic material, such as synthetic or natural rubber.

The preferably made of steel, plastic or a ceramic material cleaning element is arranged on the outer contour of the sieve or on a star finger, so that it can almost completely fill the space between two radially and axially staggered screen elements of an adjacent wave and free from deposits.

The mechanical stresses occurring due to the cleaning can be reduced to a minimum, in particular without significantly reducing the cleaning effect, which has a positive effect on the energy consumption of the entire screening device. By such lower mechanical stresses and strains, the wear of the sieve elements as well as the cleaning elements to be provided on the sieve elements can be advantageously minimized in an advantageous manner.

Furthermore, it is provided that the cleaning element projects radially outward from an associated star finger. With such an arrangement of the cleaning element on the star finger or on the star body, it is provided that the individual star fingers do not directly approach the hub or the collar of star bodies of adjacent axes of rotation. This interstice not filled by the intermeshing star fingers is ultimately filled by the cleaning element and freed by this dirt and deposits adhering there.

According to a development of the invention, it is provided that the cleaning element is wider in the axial direction than the associated star finger. The cleaning element is thus at least partially in an axial direction, but preferably on both sides in the axial direction on the associated star finger, so that by means of the cleaning element of the axial gap between star fingers of star bodies of an adjacent shaft or axis of rotation can be almost completely filled by the cleaning element.

It is further provided that the cleaning element comes to lie completely within the radial extent of the associated star finger or an associated outer region of the outer contour of the screen element. In this embodiment, the cleaning element does not over the radial outer edge of an associated star finger over. Nonetheless, scraping or cleaning along the free end section of the star finger on the adjoining waistband takes place due to the stiffening action of the cleaning element.

The non-radial protrusion of the cleaning element and the eccentric storage of Siebelements have an advantageous effect on the film and Seilfangeigenschaften the Scheibensiebs, since langfädige or fibrous materials such as wires, fibers, carpet residues, films or the like straight through the continuously changing Sieblochgröße and not radially protruding cleaning fingers are less trapped during sieving.

Thus, the mechanical stress on the cleaning finger and thus also on the star body or the sieve element occurring during operation of the disk screen can be significantly reduced overall. This has an advantageous effect on the wear and the life of the cleaning element, sieve and last of the entire screening device.

According to a further independent aspect, the invention relates to a disc screen with a number of mutually parallel rotatable axes or shafts on which individual sieve elements, in particular star discs are arranged. Here, the previously described eccentrically formed or eccentrically mounted sieve elements are provided on at least one axis of the disc screen.

Such a screen, in which sieve elements of a rotatable shaft perform a tumbling motion corresponding to their eccentricity, has a higher screening capacity than conventional screen systems known from the prior art, since the screen hole size continuously changes during operation of the screen screen and by the tumbling movement , In particular perpendicular to the plane of the axes of rotation, a vertical stroke is exerted on the screenings. This learns by a loosening, which also has an advantageous effect on the screening performance and throughput of the disc screen.

A particular advantage of the invention results from the fact that already existing star screen with consistently concentric sieve elements or star discs with the invention eccentrically or eccentrically to be stored screen elements or star discs retrofitted or can be converted.

Thus, the eccentric mounting of a sieve element according to the invention can also be produced in a particularly simple and cost-saving manner by an eccentricity is generated by concentrically formed sieve elements in a central recess which is provided in particular for storage on a rotary shaft or axis by adding a compensating body ,
Thus, it is particularly provided that adjacent to the axis, which has the eccentrically formed or eccentrically mounted sieve elements, axes are provided with concentric sieve elements, in particular star discs. In this case, for example, it is provided to provide adjacent axes or waves alternately with eccentric sieve elements according to the invention and with conventional, that is to say concentrically designed sieve elements.

However, a design in which all sieve elements or screen discs of the disc screen have the eccentric bearing or design according to the invention is also particularly advantageous. As a result, a loosening of the bulk material to be screened and throughput can be maximized.

It is provided in particular that the distance between adjacent axes of the disk screen or the diameter of the screen elements is selected such that one star finger or radially outer region of an eccentrically formed screen element or a star disk whose radially outer end section has the greatest radial distance from the axis of rotation , in at least one position of the axis up to the collar or the hub of one or more sieve elements or star body of an adjacent axis extends, so that in the position in which the said star finger substantially comes to rest on an imaginary connecting line between adjacent axes of rotation with its cleaning element provided on the adjacent hub or collar scraping along.

A cleaning effect is achieved in particular by the fact that adjacent rotary axes equipped with sieve elements rotate at different speeds, so that the outer area equipped with the cleaning element always reaches at least almost at each revolution at different positions of the outer circumference of the hub or the collar of the adjacent sieve element or along there scrapes.

According to a further advantageous embodiment of the invention it is provided that the eccentrically formed or eccentrically mounted sieve elements of a common rotatable axis are arranged rotated in the circumferential direction to each other. Consequently, such adjacent in the axial direction coming eccentric sieve elements of an axis are not formed with the same, but with mutually offset eccentricity or are correspondingly rotated but rotationally fixed to the respective shaft.

This has the advantage that also seen in the axial direction, along a shaft, the screenings undergoes uneven loosening and each locally different vertical stroke. On the other hand, by such, circumferentially offset arrangement eccentrically trained or correspondingly eccentrically mounted sieve elements, the mechanical loads occurring on the shaft are kept constant during operation and homogenized. Any unbalance of a wave caused by the individual sieve elements during operation of the sieve can thus be almost compensated on average.

According to a development, it is provided that the sieve elements arranged adjacent to one another in the axial direction on a common axis of rotation are each arranged rotated by 90 ° or by 180 ° relative to one another. Such a 90 ° or 180 ° offset causes a π / 2 or n phase-shifted vertical stroke on adjacent star bodies.

embodiments Other goals, features as well as advantageous

Figur 1

ein erfindungsgemäßes als Sternkörper ausgebildetes Siebelement in einer Seitenansicht,

Figur 2

den erfindungsgemäßen Sternkörper innerhalb eines Sternscheibensiebs im Querschnitt in einer ersten Konfiguration,

Figur 3

eine der Figur 2 entsprechende Darstellung in einer anderen Konfiguration und

Figur 4

den erfindungsgemäßen Sternkörper in einer perspektivischen Darstellung.

Applications of the present invention will become apparent from the following description of the embodiments with reference to the drawings. Show it:

FIG. 1

an inventive trained as a star body screen element in a side view,

FIG. 2

the star body according to the invention within a star disk screen in cross section in a first configuration,

FIG. 3

one of the FIG. 2 corresponding representation in a different configuration and

FIG. 4

the star body according to the invention in a perspective view.

This in FIG. 1 Sieve element 10 shown in plan view, which is designed as a sieve star or star body of a star disk, has an eccentric geometry with respect to its axis of rotation 15 or an eccentric outer contour, which is formed by the radially outer end regions of the individual star fingers 16, 24, 26. In the middle of the star body 10, a square recess 12 is provided, with which the star body can be non-rotatably pushed onto a (not explicitly shown) shaft of a star wheel screen and attached thereto. The in the FIGS. 1 to 4 shown recess here has a specially adapted to the wave geometry profile. But there are also simple geometric shapes, such as a regular four-, six- or even octagonal profile conceivable.

The individual crescent-shaped star fingers 16, 24, 26 aligned in the direction of rotation A are distributed uniformly over the circumference of the star body 10. Only the finger 24, whose free end has the largest radial distance 30 to the axis of rotation 15, differs slightly in its outer contour of the remaining fingers 16, 26. The trailing throat 20 of this finger 24 is closed in a slightly greater degree than the remaining grooves 18 located between the fingers 16, 26, so that this finger 24, which is provided with a cleaning element 22 has a slightly greater rigidity compared to the other fingers.

The in FIG. 4 In the perspective view to be recognized collar 14, which is slightly widened in the axial direction relative to the fingers 16, 24, 26, points in the in the FIGS. 1 to 4 illustrated embodiments, a concentric and thus rotationally symmetrical with respect to the rotation axis 15 training.

The grooves 18 formed between the individual fingers 16, 24, 26 have different radial distances from the collar 14 over the circumference of the star body 10. While the throat trailing the finger 26 substantially coincides with the collar 14, the grooves 18 trailing the fingers 16 or 24 are spaced radially from the collar 14.

The cleaning element 22 designed as a reinforcing part is arranged on that cleaning finger 24, which comes to lie furthest away from the axis of rotation 15, so that a cleaning and freischaben adjacent star bodies 100, 200, as for example in the Figures 2 and 3 are shown, only temporarily during the passage of the cleaning element 22 by the imaginary line connecting the axes of rotation adjacently arranged star body 10, 100, 200 takes place.

Due to the eccentricity or off-center configuration of the star body 10 reach the cleaning element 22 and the associated star finger 24 in the in FIG. 2 shown position on the collar 214 of the star body 200 to the plant. While in the rotated by almost 180 ° position of the star body 10 the Cleaning element 22, together with the associated star finger 24 on the opposite collar 114 of the other star body 100 reaches the cleansing system.

In comparison of the two representations according to FIG. 2 and 3 It can clearly be seen how the sieve holes 40, 42 formed between the individual star bodies 10, 100, 200 and on both sides of the eccentric star body change continuously during operation, that is to say in the case of the like-minded rotation of the individual star discs 10, 100, 200.

The adjacent adjacent to the eccentrically shaped star wheel 10 arranged further star discs 100, 200 are in the embodiments shown here is substantially concentric, ie radially symmetrical. These have, in the same way as the star disk 10, in each case a through opening 112, 212 and in each case a cleaning element 122, 222 provided on a cleaning finger 124, 224.

All shown in Figures 1 to 3

Cleaning elements 22, 122, 222 do not protrude over the associated star fingers 24, 124, 224 in the radial direction, but protrude above this primarily in the axial direction, so that in the meshing movement of star fingers adjacent star disk 10, 100, 200 of the larger axial deflection of the respective collar 14, 114, 214 formed opposite the fingers gap can be almost completely filled and cleaned by the cleaning element 22, 122, 222.

The in the FIGS. 1 to 3 illustrated, substantially concentric formation of the collar 14, 114, 214 of each Star body 10, 100, 200 allows that not only the collar 114, 214 of the star discs 100, 200 is cleaned by the cleaning element 22 of the eccentric star disk body, but that, conversely, the eccentrically shaped star body 10 centrally formed collar 14 of the cleaning elements 122 and 222 of the adjacent star discs 100, 200 can be reliably removed from deposits.

The perspective view according to FIG. 4 shows the star disc according to the invention in an exploded view. Here, the two elements 14, which each side of the disc each form a collar formed as a separate and removable sliding elements, but in other embodiments, also in one piece with the star fingers having disc can be connected. The slide having the star fingers can also have a two-component construction and can be formed by joining two halves together.

LIST OF REFERENCE NUMBERS

10

star body

12

recess

14

Federation

15

axis of rotation

16

star fingers

18

throat

20

throat

22

cleaning element

24

star fingers

26

star fingers

30

external outline

40

screen hole size

42

screen hole size

100

star body

112

recess

114

Federation

122

cleaning element

124

star fingers

200

star body

212

recess

214

Federation

222

cleaning element

224

star fingers

Claims (15)

1. Screen element of a disc screen, which comprises a plurality of rotatable axles which are oriented parallel to one another and at each of which a respective plurality of mutually axially spaced-apart screen elements can be arranged to be rotationally fast, wherein for variation of the screen hole size (40, 42) in operation of the disc screen the outer contour of the screen element (10) in a projection perpendicular to the axis (15) of rotation is formed to be eccentric with respect to the axis (15) of rotation and has a plurality of star fingers (16, 24, 26) of crescent-like construction, characterised in that a cleaning element (22, 122, 222) is arranged at that star finger (24) of which the free end has the greatest radial spacing from the axis (15) of rotation.
2. Screen element according to claim 1, characterised in that a collar (14) constructed concentrically with respect to the axis of rotation and widened in axial direction relative to the outer contour of the screen element is provided.
3. Screen element according to claim 1 or 2, characterised in that the screen element (10) has a multi-sided, polygonal, elliptical, double-elliptical or star-shaped (16, 24, 26) outer contour.
4. Screen element according to any one of the preceding claims, characterised in that the edges or end sections, which come to lie outwardly in radial direction, of the outer contour (16, 24, 26) are arranged at different spacings from the axis (15) of rotation.
5. Screen element according to claim 4, characterised in that the radially outwardly disposed end sections of star fingers (16, 24, 26) arranged adjacently in circumferential direction have a continuously changing spacing from the axis (15) of rotation in the circumferential direction.
6. Screen element according to claim 4 or 5, characterised in that the star fingers (16, 24, 26) have different radial lengths.
7. Screen element according to any one of claims 4 to 6, characterised in that the end sections, which are disposed outwardly in radial direction, of the star fingers (16, 24, 26) lie on a circle having a centre radially offset with respect to the axis (15) of rotation of the star body (10).
8. Screen element according to any one of the preceding claims, characterised in that the cleaning element (22; 122; 222) is constructed to be wider in axial direction that the star fingers (16, 24, 26).
9. Screen element according to any one of the preceding claims, characterised in that that the cleaning element (22; 122; 222) comes to lie completely within the radial extent of the associated start finger (24; 124; 224).
10. Disc screen with a plurality of rotatable axles which are oriented parallel to one another and at which screen elements (10, 100, 200) are arranged to be secure against relative rotation, wherein eccentrically constructed screen elements (10) according to any one of the preceding claims are arranged at at least one axle.
11. Disc screen according to claim 10, characterised in that axles with concentrically constructed screen elements (100, 200) are provided adjacent to the axle having eccentrically constructed screen elements (10).
12. Disc screen according to claim 10, characterised in that all axles are equipped with eccentrically constructed screen elements (10) according to any one of claims 1 to 10.
13. Disc screen according to any one of claims 10 to 12, characterised in that the spacing between adjacent axles is so selected that the star finger (24) having the greatest radial spacing from the axis (15) of rotation of an eccentrically constructed screen element (10) reaches, in at least one setting of the axle, almost up to or directly against the collar (114, 214) of one or more star bodies (100, 200) of an adjacent axle.
14. Star disc screen according to any one of claims 10 to 13, characterised in that the screen elements (10), which are arranged adjacent to one another in axial direction, of an axle are arranged to be turned relative to one another in circumferential direction.
15. Star disc screen according to claim 14, wherein screen elements (10) arranged adjacently in axial direction are arranged at the axle to be respectively turned relative to one another through 90° or 180°.

Images