EP3017109B1 - Screening device - Google Patents

Description

The invention relates to a screening device which is intended for pulp suspensions in the paper industry and is used, for example, in sorters, pressure sorters and the like.

Out EP 1 114 218 B1 a screening device of the generic type is known, which has a screen surface forming, substantially cylindrical screening device. The screening device is supported by a radially spaced arranged reinforcing device, which is designed in particular in the form of a support shell, which is also referred to as a "backup cylinder". The screening device is interchangeable as a unit to replace the heavily used and prone to wear screen device in a simple way and to be able to use the reinforcing device, such as the support shell again.

Out EP 0 471 195 A1 and the associated one US-A-5,200,072 Screen plates, screen cylinders and methods for their production are known. In the case of a cylindrical screening device, the design is such that the screening device or the corresponding screening part is detachably and interchangeably connected to a support cylinder serving as reinforcement device. In order to reduce the manufacturing costs and the production time, therefore, a worn sieve device only needs to be replaced, while the reinforcing device, in particular the support cylinder, can be reused. For detachable connection of screening device and shell-shaped reinforcing device, the outer diameter of the screening device is dimensioned slightly larger than the inner diameter of the support cylinder. By means of a temperature-dependent Aufschrumpfvorganges then the screening device and the amplifying device are non-positively into each other set, and if necessary, this compound can still be secured, for example by means of welding, rivets, screws, adhesives, solder or the like.

In all these known screening devices, although a partially time-consuming and labor-intensive replacement of the screening device is provided, but the screening device is a self-consistent structure, which as such and whole within the reinforcing means, in the form of the support jacket with appropriate suitable means is releasably fixed.

The invention aims to provide a screening device of the generic type which is flexibly adaptable to different screening tasks and sieving requirements and can be used to increase efficiency. In particular, the screening device should be displayed and manufactured inexpensively. Also, an assembly-friendly construction is to be created, whereby possible potential assembly errors are avoided, in particular, the smallest possible number of parts to be placed together should be present.

According to the invention, for this purpose, a screening device, for pulp suspensions in the paper industry, with a screen surface forming a substantially cylindrical screen basket and a radially spaced therefrom and surrounding the screen basket reinforcing means, provided in the form of a support shell which has an end flange at one axial end, which is characterized in that the screening device comprises at least two separate screen baskets, which are axially successively arranged within the reinforcing device in the form of a support jacket with the interposition of a variable diameter intermediate ring such that the substantially cylindrical screen baskets in cooperation with the end-side end flange of the reinforcing device, a Cover part, a bottom part and the intermediate ring are centrally positioned clamped and fixed.

The screening device according to the invention thus comprises a smaller number of parts to be assembled, namely a support shell, at least two screen baskets, an intermediate ring, a bottom part and a cover part. The interpretation at the Screening device according to the invention is made such that thanks to the variable diameter intermediate ring, the two axially arranged one behind the other screen baskets are automatically centered and aligned relative to each other in the interior of the reinforcing means in the form of the support shell fixed in a predetermined manner. The installation effort and the assembly times for assembling a screening device according to the invention can thereby be particularly optimized, and at the same time a reuse of the reinforcing means in the form of the support shell, ensured. In the screening device according to the invention the variable diameter intermediate ring on the one hand performs the function of a centric positioning of both baskets with respect to the reinforcing device and at the same time a clamping and locking function in the interaction of associated parts of the reinforcing device and the or the front ends of the baskets. Due to the small number of fitting into one another components can also be largely avoided mounting errors. The two screen baskets arranged one behind the other allow each optionally separate and flexible adaptation to the desired screening tasks and sieving requirements. Thus, in a simple manner and structurally simple, a universal adaptation of the screening device to the respective conditions of use is possible.

In a preferred embodiment, the diameter variable intermediate ring is divided, preferably slotted. Alternatively, the variable diameter intermediate ring may be formed by an elastomeric ring. In both cases, the intermediate ring is designed such that the diameter under the action of an axial, the parts of the screening device against each other spanning clamping force can expand or spread in diameter such that the baskets are aligned relative to each other and also relative to the support center, and at the same time also made a determination in this position.

In particular, in the screening device according to the invention, the cover part and the bottom part in cooperation with the front ends (Siebkorbflansch) of the screen baskets each form a torsion-proof unit. In particular, an anti-rotation at the respective ends of the screen baskets or the Siebkorbflansche required to effectively prevent relative movement of the two baskets in the operating state. Preferably, the intermediate ring and the front ends of the screen baskets form a torsion-proof unit, so that a safe and reliable and fixed assignment of intermediate ring and screen baskets is given in the screening device according to the invention. In connection with the axial support of Siebkorbstirnende and support shell a twist-proof fixation can also be achieved by means of frictional engagement.

Conveniently, the rotation is formed by an interlocking pin and groove arrangement. This is an embodiment of an anti-rotation device that is simple in terms of design and construction.

According to a preferred embodiment of the screening device, the design is such that the cover part, the bottom part and the intermediate ring form a non-positive connection with the screen baskets by means of a splined connection. The wedge connection can be expediently designed as a conical seat connection. By means of this frictional connection, after final assembly of the parts of the screening device according to the invention, a final definitive allocation of the components to one another is obtained, but a release of the frictional connection is achieved by a simple separation and a simple removal or disassembly of the component.

In order to enable a universal adaptation to the respective screening tasks and sieving requirements, the screen baskets can have different slot widths and / or slot shapes, in particular they can have different pitches, profile depths, profile sizes or profile inclinations.

In particular, the sieve device according to the invention is designed such that, for its assembly, a first sieve basket is arranged in the reinforcing device under rest on the bottom part, the variable diameter intermediate ring is placed on the upper axial end of the first sieve basket, the second screen basket is arranged thereon, and then the cover part is arranged on the upper axial end of the second screen basket, wherein at an axial Spannkraftbeaufschlagung the above arrangement, the intermediate ring is widened or expanded in diameter and in the radial direction without gaps at the associated axial ends of the Sieve baskets applies. This ensures that during assembly inevitably all possible passage gaps are effectively closed to the entire arrangement of the components. Furthermore, it is also achieved by this gap-free arrangement that the axial ends (end flanges) of the screen baskets, the pressure forces on the reinforcing jacket (backup cylinder) are transmitted and thereby increase the overall stability of the screening device and can be improved.

In summary, the invention specifies a screening device, which in the interior of a backup cylinder serving as an amplification device has one behind the other axially arranged at least two separate screen baskets. By means of a between the axial ends of the screen baskets or Siebkorbflanschen arranged intermediate ring which is variable in diameter, then the arrangement of reinforcing means in the form of the backup cylinder, the two screen baskets and the interposed intermediate ring is achieved under an axial Spannkraftbeaufschlagung that during assembly of this screening device the separate screen baskets are clamped centrically positioned and fixed to the reinforcing means in the form of the backup cylinder.

The sieve device according to the invention can therefore be composed of easy-to-assemble components that are designed to be easy to assemble. In particular, the screening device according to the invention comprises the smallest possible number of individual parts to be constructed together.

The invention will be explained in more detail below with reference to the accompanying drawings with reference to preferred embodiments.

Fig. 1

eine schematische Aufbauzeichnung der Siebvorrichtung nach der Erfindung im Halbschnitt und Queransicht;

Fig. 2a und 2b

schematische Ansichten zur Verdeutlichung der Art und Weise der axialen Spannkraftbeaufschlagung;

Fig. 3a und 3b

schematische Ansichten zur Verdeutlichung der Funktion des Zwischenrings vor und nach der Spannkraftbeaufschlagung bei der Siebvorrichtung nach Erfindung;

Fig. 4a und 4b

schematische Ansichten unter Zuordnung zu den Fig. 3a und 3b;

Fig. 5a und 5b

eine Schnittansicht und eine perspektivische schematische Ausschnittsansicht zur Verdeutlichung einer Verdrehsicherung im oberen Bereich der Siebvorrichtung;

Fig. 6a und 6b

eine schematische Schnittansicht und perspektivische Ausschnittsansicht zur Verdeutlichung einer Verdrehsicherung im Zwischenbereich eines Zwischenrings;

Fig. 7a und 7b

eine schematische Schnittansicht und eine perspektivische Ansicht zur Verdeutlichung einer Verdrehsicherung am Bodenbereich der Siebvorrichtung nach der Erfindung; und

Fig. 8a und 8b

schematische Ansichten zur Verdeutlichung einer alternativen Ausführungsform eines durchmesservariablen Zwischenrings.

It shows:

Fig. 1

a schematic plan view of the screening device according to the invention in half section and transverse view;

Fig. 2a and 2b

schematic views to illustrate the manner of the axial clamping force;

Fig. 3a and 3b

schematic views to illustrate the function of the intermediate ring before and after the clamping force application in the screening device according to the invention;

Fig. 4a and 4b

schematic views under assignment to the Fig. 3a and 3b ;

Fig. 5a and 5b

a sectional view and a perspective schematic sectional view to illustrate an anti-rotation in the upper part of the screening device;

Fig. 6a and 6b

a schematic sectional view and a perspective cutout view to illustrate an anti-rotation in the intermediate region of an intermediate ring;

Fig. 7a and 7b

a schematic sectional view and a perspective view to illustrate an anti-rotation at the bottom portion of the screening device according to the invention; and

Fig. 8a and 8b

schematic views to illustrate an alternative embodiment of a variable diameter intermediate ring.

Those in the figures of the drawing are the same or similar parts with the same reference numerals. Furthermore, the illustrations are non-limiting embodiments.

With reference to FIG. 1 should be briefly explained the essential components of a generally designated 1 screening device according to the invention. The screening device 1 comprises a reinforcement device 2 in the form of a support jacket or "backup cylinder". In the interior of this amplification device 2, two separate baskets 3, 4 are arranged axially one behind the other in the illustrated embodiment. Between the two screen baskets 3, 4 a variable diameter intermediate ring 5 is arranged, which cooperates with the respective end faces of the two abutting baskets 3, 4 in the manner described in more detail below. At the bottom of the screening device 1, a bottom part 6 is provided, in which a frontal axial end of the screen basket 4 by means of a spline connection, preferably a conical seat connection 7, is used. At the top in FIG. 1 the reinforcing device 2 is closed by a cover part 8, which cooperates on the one hand with a top end of a screen basket 3 via a non-positive connection in the form of a wedge connection designed as a conical seat connection 9. On the other hand, the lid part 8 is attached to the reinforcing device 2 by means of clamping screws 12. An intermediate ring 5 is arranged between the reinforcing device 2 and the two axially mutually facing ends of the two screen baskets 3, 4. To assemble such a total of 1 designated sieve a first sieve basket 4 is inserted into the interior formed by the reinforcing device 2 in the form of a support cylinder such that the lower axial end face of the screen basket 4 via the frictional connection in the form of a conical seat connection 7, for example, fits on the Floor part 6 rests. Then the diameter variable intermediate ring 5 is placed on the upper axial end of the first screen basket 4. The second screen basket 3 is then arranged above the intermediate ring 5 axially aligned with the first screen basket 4 and works via a frictional connection, preferably a spline 11, with the intermediate ring 5 together. Finally, the lid part 8 is then mounted on the upper axial end of the second screen basket 3 via the non-positive conical seat connection 9. With the help of clamping screws 12 is an axial Spannkraftbeaufschlagung the overall arrangement of cover part 8, the two screen baskets 3, 4, the interposed intermediate ring 5 and the bottom part. 6

On the hand of the FIGS. 2a and 2b This Spannkraftbeaufschlagung between the cover part 8, the reinforcing device 2 in the form of a support jacket and the second screen basket 3 is illustrated schematically. In FIG. 2a the conditions are indicated schematically when the cover part 8 loose over the cone seat connection 9 rests. As in FIG. 2a indicated, in this state, for example, a distance a _{1 is} present. As in FIG. 2b is clarified, this distance is much smaller after tightening the clamping screws 12 and is designated there with a ₂ .

On the hand FIGS. 3a and 3b the operation of the intermediate ring 5 is illustrated schematically. In FIG. 3a is under assignment to FIG. 2a a schematic representation taken in which the intermediate ring 5 to the inner wall of the reinforcing device 2, for example, a distance b ₁ has. The two axial ends of the screen baskets 3, 4 have after FIG. 3a for example, a distance a ₂ . In FIG. 3b the condition is shown, if appropriate FIG. 2a an axial clamping force is applied. In this axial clamping force, the axial distance between the two screen baskets 3, 4 is smaller and decreases to a ₃ . The intermediate ring 10 is pressed directly against the inner wall of the reinforcing device 2 in the form of a support jacket, and the above in FIG. 3a With b ₁ designated distance is canceled. In this case, compressive forces can then be transmitted to the reinforcing device 2 via the axial ends (end flanges) of the screen baskets 3, 4 in order to give the screening device 1 an overall increased and better stability.

With reference to the FIGS. 4a and 4b The relationships in a plan view are illustrated schematically. In the illustrated, preferred embodiment, the intermediate ring 5 is designed to be of variable diameter in that it is split or slotted, which means that this diameter-variable intermediate ring 5 is not closed at its circumferential ends, but a distance c ₁ in the circumferential direction is present.

How out FIG. 4b under assignment to FIG. 3b can be seen, is spread by the axial Spannkraftbeaufschlagung the intermediate ring 5 in the circumferential direction such that the distance between the circumferential ends of the split intermediate ring 5 is opposite to c ₂ FIG. 4a increased. At the same time, the distance b ₁ between the inner wall of the reinforcing device 2 is released under the action of the clamping force.

As is clear from the FIGS. 2a to 4b can be seen, the variable diameter intermediate ring 5 between the two axially opposite ends of the two screen baskets 3, 4 arranged in the interior of the reinforcing device 2 in the form of a support jacket in such a manner that the screen baskets 3, 4 in cooperation with an end-side end flange 13 of the reinforcing device 2 in the form of a support jacket, the cover part 8, the bottom part 6 and the diameter variable intermediate ring 10 are positioned centrally fixed and fixed.

In the screening device according to the invention thus takes place at the axial Spannkraftbeaufschlagung by means of clamping screws 12 forcibly a centric arrangement of the two baskets 3, 4 in a series connected arrangement, and these two baskets 3, 4 are at the same time in cooperation with the diameter variable intermediate ring 5 against each other and against Inner wall of the reinforcing device 2 firmly clamped.

The FIGS. 5a and 5b illustrate an optionally provided anti-rotation 14, which is designed in the example shown as a pin and groove assembly 15. This rotation 14 prevents relative rotation of the cover part 8 and the second screen basket. 3

On the hand Figures 6a and 6b an anti-rotation 16 is shown, which is also preferably designed in the form of a pin and groove assembly 17, which is effective between the two axially abutting ends of the two screen baskets 3, 4, and a rotation of the screen baskets 3, 4 relative to each other effectively prevented ,

On the hand FIGS. 7a and 7b is an optionally provided in the lower region anti-rotation 18 illustrates which is also preferably designed as a pin and groove assembly 19 and effectively prevents relative rotation of the first screen basket 4 and the bottom part 6.

On the hand FIGS. 8a and 8b Finally, an alternative embodiment of a variable diameter intermediate ring 5 'is clarified, which is designed in the form of an elastomeric ring 20. This elastomer ring 20 has an uninterrupted or continuous configuration and is based on the loosely attached state FIG. 8a under the action of the axial clamping force application accordingly FIG. 8b deformed and pressed, so that even in the FIG. 8b shown state no gap between the inner wall of the reinforcing device 2 and the corresponding axial ends or the end flanges of the two screen baskets 3, 4 is present.

Claims (10)

1. Sieve device (1) for pulp suspensions in the paper industry, with a substantially cylindrical sieve basket (3, 4) forming a sieve surface, and a reinforcement device (2) spaced radially from this and surrounding the sieve basket (3, 4) in the form of a support jacket, having an end flange (13) at one axial end, characterised in that the sieve device (1) comprises at least two separate substantially cylindrical sieve baskets (3, 4), which are arranged axially one behind the other inside the reinforcement device (2) in the form of a support jacket with a variable diameter intermediate ring (5) so that the essentially cylindrical sieve baskets (3, 4) are clamped and fixed in a central position in conjunction with the end flange (13) of the reinforcement device (2), a cover part (8), a base part (6) and the intermediate ring (5).
2. Sieve device in accordance with claim 1, characterised in that the variable diameter intermediate ring (5) is divided, preferably slit.
3. Sieve device in accordance with claim 1, characterised in that the variable diameter intermediate ring (5) is formed by an elastomer ring (20).
4. Sieve device in accordance with one of the preceding claims, characterised in that the cover part (8) and the base part (6) in conjunction with the end faces of the sieve baskets each form a non-twistable unit (14, 18).
5. Sieve device in accordance with one of the preceding claims, characterised in that the intermediate ring (5) and the end faces of the sieve baskets (3, 4) form a non-twistable unit (16).
6. Sieve device in accordance with claim 4 or 5, characterised in that the non-twistable unit (14, 16, 18) is configured in the form of a pin and groove arrangement (15, 17, 19).
7. Sieve device in accordance with one of the preceding claims, characterised in that the cover part (8), the base part (6) and the intermediate ring (5) form a friction-locking connection with the sieve baskets (3,4) by means of a wedge connection.
8. Sieve device in accordance with one of the preceding claims, characterised in that the wedge connection it in the form of a conical seat connection.
9. Sieve device in accordance with one of the preceding claims, characterised in that, for assembly of the sieve device (1), a first sieve basket (4) is positioned in the reinforcing device (2) to rest on the base part (6), the variable diameter intermediate ring (5, 5') is placed on the upper axial end of the first sieve basket (4), the second sieve basket ( 3) is positioned on it and then the cover part (8) is positioned on the upper axial end of the second sieve basket (3), so that when an axial tensioning force is applied to the above arrangement the intermediate ring (5) spreads in a circumferential direction and bears in a radial direction on the associated axial ends of the sieve baskets (3, 4) without a gap.
10. Sieve device in accordance with one of the preceding claims, characterised in that the sieve baskets (3, 4) have different slit widths and/or slit shapes, in particular different divisions, profile depths, profile sizes or profile slopes.

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