Screen, in particular pressure screen

Abstract

The invention provides a screen (S1-S14), in particular a pressure screen or a pressure screen device which has an inlet (Z) and at least one axially spaced accept (Ak) and reject (R). Screen elements (2) are arranged in the inlet space (ZR) of the screen (S1-S14) and in the inlet space (ZR) of the screen elements, spaced radially therefrom, there is a rotor (3) which rotates by means of a driving means (G). In the axial direction between the inlet (Z) and accept (Ak), the rotor comprises at least two rotor regions (A, B) which rotate at different rotational speeds. Each rotor region (A, B) is assigned a corresponding screen basket region (2A, 2B, 2'A, 2'B). These rotor regions can rotate in the same direction or in opposite directions. The screen is operable according to the inflow principle or the outflow principle, optionally also in combination.

Description

[0001] Sorters, especially pressure sorters

[0002] Description

[0003] The invention relates to a sorter, in particular a pressure sorter or, more generally, to pressure screening devices. Such a sorter has an inlet and at least one axially spaced-apart accept and reject. Furthermore, screening elements are provided in the usual manner, for example in the form of a screen basket. A radially spaced rotor is provided in the inlet space of the screening elements, which rotates in an axial direction within the inlet space of the screening elements.

[0004] EP 0 404 624 B1 discloses a method for controlling pressure screening devices and pressure sorters. In addition to an inlet, this pressure screening device comprises an accept outlet and a reject outlet axially spaced therefrom. Furthermore, a screening element in the form of a screen basket, or more generally, a screen plate, is arranged in the pressure screening device. Furthermore, a screen plate treatment device, which is a rotor blade arrangement, is provided radially spaced from the screen basket, and a deflector plate arrangement is provided radially spaced therefrom. The deflector plate arrangement and the screen plate treatment device (rotor) both feed the fiber suspension to the screen plate and are provided with separate drive devices, each of which is connected to these devices. This allows the screen plate treatment device (rotor) and the deflector plate arrangement to be driven, in particular, at the desired speed.In this state-of-the-art technology, the rotor elements serve to supply or divert flow from axial to radial to the screen element or screen basket. The rotor element is effective across the entire axial extent of the screen element. A second rotor blade arrangement with a separate drive and separate speed is arranged downstream for the cleaning action of the screen element (screen basket) by means of pressure and suction on the screen element surface. This second rotor blade arrangement sweeps the entire axial extent of the screen element. Both rotor elements are arranged between the inlet and the accept, but the individual rotor elements are arranged radially one behind the other and sweep the entire height of the screen element (screen basket). Thus, a different mode of operation is realized.

[0005] Furthermore, US 3,939,065 of February 17, 1976, and US 3,933,649 of January 20, 1976, disclose screening devices, particularly pressure screening devices, which comprise two conically shaped and radially spaced first and second screening drums. Thus, this prior art shows a two-stage screening or sorting device with two conical screening elements, each of which is assigned two independent drives.

[0006] DE 102 06 595 A1 deals with a non-standard wood chip spreading device. DE 33 47 115 C2 shows a conical screening device for a screw extractor. DE 16 37 850 U shows a screening drum for waste processing.

[0007] The invention aims to improve sorting efficiency and reduce energy and operating costs.

[0008] According to the invention, a sorter, in particular a pressure sorter, is provided with an inlet and at least one axially spaced-apart accept and reject, with screening elements and a rotor arranged radially spaced therefrom, which rotates in the inlet space of the screening elements by means of a drive device. According to the inventive concept, the sorter is designed such that the rotor comprises at least two downstream rotor regions in the axial direction between the inlet and accept, which rotate at different speeds, and the rotor regions are each assigned to corresponding screening element regions.

[0009] This allows the respective rotor sections to be adapted to the consistency and / or type of the material being sorted, resulting in significantly improved sorting efficiency for the sorter overall. Furthermore, the at least two rotor sections, which rotate at different speeds, enable the energy and operating costs of such a sorter to be reduced thanks to the adaptation to the sorting mass or material.

[0010] Further preferred embodiments of the invention are set out in claims 2 to 25.

[0011] The rotor sections can rotate in the same direction but at different speeds, or they can rotate in opposite directions. This allows for further optimization and adaptation to the properties of the material being sorted.

[0012] According to a preferred embodiment, the inlet-side rotor section rotates slower than the reject-side or downstream rotor section. This allows the incoming material to initially remain longer on the inlet side than in the subsequent reject-side or downstream rotor section. This allows the sorting process of the material to be sorted to be optimized and controlled accordingly. With this design, the inlet-side rotor section rotates 10% to 60%, preferably in a range of approximately 20% to 40%, slower than the reject-side or downstream rotor section.

[0013] The sieve elements are preferably essentially cylindrical, but they can also be essentially conical. This depends in particular on the design of the sorter.

[0014] Preferably, the sieve elements have different diameters and the rotor areas also have different diameters and work together with the sieve elements with different diameters.

[0015] Preferably, the rotor blades of the rotor sections are spaced at different distances from the walls of the screen elements, allowing for correspondingly different sorting conditions. The distance between the rotor blades and the screen element is 1.5 mm to 10 mm, preferably 2.5 mm to 6.0 mm. As can be seen from the figures in the drawing, the rotor blades of the rotor sections can be positioned upstream of the screen elements in the inlet chamber.

[0016] A preferred embodiment is characterized in that the accept flow direction through the screen element is radially inward (inflow design). Optionally, the at least two screen elements are flowed through in different radial directions.

[0017] In particular, the at least two rotor regions can also have different rotor designs. The rotor regions preferably comprise an open rotor design, particularly for low-consistency applications, and a closed drum design, particularly for high-consistency applications.

[0018] In a preferred design of the sorter, a common inlet is assigned to at least two rotor areas and at least two axially spaced, separate acceptance outlets are provided.

[0019] In a preferred embodiment of the invention, the drive device for the rotor sections comprises a gearbox with at least two shaft outputs for driving the rotor sections differently. This results in a compact, space-saving sorter design.

[0020] Alternatively, the drive device comprises at least two separate drives. The drive device comprises an axial hollow shaft for passing through the drive shaft for the respective other rotor section.

[0021] In general, the drive(s) can be located on top of the sorter and / or on the bottom of the sorter. In a preferred embodiment, the sorter is designed such that, when configured with more than two spaced-apart rotor sections, these rotate at different speeds and / or have different directions of rotation. This allows the operating conditions and operating conditions to be flexibly adapted to the properties of the material being sorted.

[0022] In summary, the main idea underlying the invention is that the rotor comprises at least two rotor sections in the axial direction between the inlet and the acceptor, which rotate at different speeds to achieve optimal adaptation to the material to be sorted. These rotor sections are each assigned to corresponding sieve element sections.

[0023] Further details, features and advantages of the invention will become apparent from the following description of non-limiting preferred embodiments with reference to the accompanying drawings.

[0024] Figures 1—14 of the drawing show schematically a sectional view of different embodiments of the essential concept according to the invention.

[0025] In the figures of the drawing, identical or similar parts are provided with the same reference symbol.

[0026] Figure 1 shows a first design of a sorter S1 which has a sorting housing 1. An inlet Z for the material to be sorted is arranged near the top of the sorting housing 1. At an axial distance from this, an accept outlet Ak and a reject outlet R are provided in the sorting housing 1 near the bottom. Within the inlet space in the sorting housing 1, a sieve element 2 in the form of a sieve basket is arranged, which is preferably cylindrical. Radially spaced from this is a rotor, designated overall by 3. The rotor 3 comprises a first rotor region, which is formed by a schematically indicated rotor A, and a second rotor region, which is formed by a schematically indicated rotor B. The drive device for the rotor A comprises a motor A1, a pulley A2 and a drive shaft A3.The second rotor region, formed on the reject side or downstream of the rotor region, has a drive device comprising a separate motor B1, a pulley B2, and a drive shaft B3 designed as a hollow shaft. Thus, the embodiment according to Fig. 1 has a sorter S1 with two separate drive devices for the rotor regions A and the second rotor region B. The drive shaft B3 is designed as a hollow shaft and is mounted in a suitable manner axially aligned with the drive shaft A3.

[0027] Arrows indicate the directions of rotation of rotors A and B. The length of the arrows indicates that the inlet-side rotor section A rotates more slowly than the reject-side, or downstream, rotor section B. Both rotor sections or rotors A and B rotate in the same direction. In the embodiment of the sorter S1 shown in Figure 1, separate drive devices are provided for rotor section A and rotor section B. Separate screening element sections 2A and 2B (screen basket sections) are assigned to rotor sections A and B, respectively.

[0028] In the embodiment shown schematically in Figure 2, however, and also in the other Figures 2 to 11, a common drive motor M is provided, to which a common pulley arrangement RS is assigned. Interposed to the common pulley arrangement RS is a gearbox G, which comprises at least two shaft outputs (shown schematically) for driving the rotor areas A, B. As shown in the embodiment according to Figure 2, in the area of ​​the sieve element 2 (sieve basket), the two rotor areas A and B rotate in the same direction but at different speeds, as is illustrated by the length of the arrows indicating the rotational movement.

[0029] In the embodiment of the sorter S3 according to Figure 3, however, the rotor areas A, B rotate in opposite directions and the rotor area A rotates more slowly than the rotor area B, as shown by the arrows. All other details of this embodiment S3 essentially correspond to the embodiment of the sorter S2 according to Figure 2.

[0030] Another alternative embodiment of a sorter is shown in Figure 4, which is designated overall by S4 there. In contrast to the previous figures, here the inlet Z is arranged near the bottom of the sorter S4, while the reject outlet is arranged near the top of the sorter S4 and the accept outlet Ak is arranged approximately axially centrally between the reject outlet R and the inlet Z. This sorter S4 also has a heavy dirt separation outlet 5. Furthermore, the embodiment S4 according to Figure 4 comprises a combination of different rotor design variants, namely a drum design for high-consistency applications and an open rotor design for low-consistency applications. Further details of the drum design for high-consistency applications are illustrated schematically in Figure 4a.The drum structure has a cylindrical rotor body 10, with the rotor blades 11 attached to the outer wall of the drum-shaped rotor body. In Figure 4, for example, rotor region A has a drum structure.

[0031] Figure 4b illustrates an open rotor design intended for low-consistency applications and forming rotor area B or rotor B. The open rotor design according to Figure 4b comprises a centrally arranged rotor body 12, to which the rotor blades 13 are attached by means of a rotor blade attachment 14. These rotor blades 13 also sweep over the inner surface of the sieve element 2, as in Figure 4a.

[0032] Figure 5 shows a variant of a sorter S5 in which the rotor regions or the rotors A, B have different speeds, as is achieved in the preceding embodiments either with separate drives or a gear G. In the design of the sorter S5, the sieve element 2 comprises two sieve elements 2a and 2b. Separate acceptance outlets Ak1 and Ak2 are each assigned to these sieve elements 2a, 2b. Figure 6 shows a sorter referred to overall as S6. The basic design and structure are essentially the same as the sorter S2 shown in Figure 2. However, here the sieve elements 2a' and 2b have different diameters and / or the rotor regions A, B can also have different diameters. The assigned sieve element regions are designated 2'A and 2'B.By changing the diameters of the sieve elements 2a', 2b' and / or by changing the diameters of the rotor areas A, B, different sorting conditions can be set accordingly.

[0033] Figure 7 shows a variant in which the sorter S7 has rotor areas A, B with different diameters, while the diameter of the sieve elements 2 in the form of a sieve basket remains the same. This allows different distances to be achieved between the sieve element 2 and the outer surface of the rotor areas A, B. In the embodiment according to Figure 7, the rotor area A with the smaller diameter is arranged near the inlet side, while the rotor area B with the larger diameter is arranged on the acceptance side. Here, too, the sorting conditions between rotor area A and rotor area B can be adapted to the material to be sorted. Of course, the area with the smaller diameter and the rotor area with the larger diameter can also be selected in the reverse order to that shown in Figure 7. The distance between the rotor blade 13 and the sieve element 2 is between 1.5 mm and 10 mm, preferably 2.5 mm to 6.0 mm.A special design is characterized in that the rotor blades of the inlet-side rotor area (A) have a distance from the wall of the screen elements (2, 2', 2a) that is 0% to 30% smaller than the rotor blades of the reject-side or downstream rotor area.

[0034] Figure 8 shows a sorter S8 which is based on the basic concept of the sorter S5 according to Figure 5, but the sieve elements 2a, 2b have different diameters as in the embodiment according to Figure 6.

[0035] Figure 9 shows a sorter, designated overall by S9, in which several rotor areas A to F are provided, schematically illustrated with the rotors A to F. These rotor areas A to F rotate at different speeds or in different directions of rotation. Otherwise, the basic structure of the sorter S9 is identical to the sorters shown and explained above. Separate screening element areas 2A, 2B (screening element areas ACE; BDF) are assigned to each rotor area.

[0036] The sorter shown in Figure 10 has essentially the same basic structure as Figure 1, but the drive motor A1 is located near the top of the sorter S10. This eliminates the complex one-sided shaft / hollow shaft drive through the pressure sorter housing base shown in Figure 1.

[0037] Figure 11 schematically shows a sorter S11 in which conical rotor regions A', B' are provided. Similarly, the sieve element 2' is also conically shaped and has associated sieve element regions 2'A, 2'B. The drives for the rotor regions are designed according to the previously explained embodiments.

[0038] Finally, Figure 12 shows a sorter S12 which, in terms of its basic design, is designed similarly to the sorter S10 in Figure 10, but here it is additionally made clear that the sorting element in the form of the screen basket 2 is also driven in rotation by means of the motor A2 which is arranged above the sorting housing 1.

[0039] Figure 13 shows a sorter S13, which, in terms of its basic design and drive arrangement, is designed similarly to the sorter S10. However, the rotor A is arranged on the outer region of the sieve element area A2. Thus, the suspension to be sorted flows from the outer diameter of the sieve element 2 into the interior of the sieve element 2. The flow direction of this arrangement is centripetal; thus, this sorting area operates according to the inflow principle. The accept flow of the sieve element 2A is now the inflow flow of the sieve element 2B, which is subsequently treated in the rotor area B in a radially outward direction (outflow principle) through the sieve element 2B. Thus, the treatment of the material to be sorted takes place in interdependent stages.

[0040] Figure 14 shows a sorter S14 in which both rotor sections A and B operate according to the inflow principle. The inflow Z here originates from the outer diameter of the screen element 2. Each rotor section is driven by a shaft output associated with a respective rotor section at a different rotor speed. In Figure 13, rotor B is spaced further apart from the screen element 2 than rotor A.

[0041] The sieve element can be designed in a variety of ways. Sieve elements with slotted openings made of profiled bars and rings, as well as perforated sheet metal constructions with slotted, round-hole, or other opening geometries, are possible. Meshes can also be used as sieve elements.

[0042] Of course, the invention is not limited to the above-described and illustrated preferred embodiment, but numerous variations and modifications are possible, in particular combinations of the preferred embodiment. However, all preferred embodiments and all variant designs have in common that at least two different rotor regions A, B are present, which preferably rotate at different speeds, and that separate sieve element regions 2A, 2B, 2'A, 2'B are assigned to each of the different rotor regions A, B.

[0043] Reference symbol

[0044] S1 to S14 sorters in total

[0045] 1 sorting housing

[0046] 2 Sieve element in the form of a sieve basket

[0047] 2A, 2B sieve element area

[0048] 2' Sieve element in Figure 11 conical

[0049] 2'A, 2'B sieve element area

[0050] 3 Rotor

[0051] 5 Heavy dirt outlet

[0052] 10 Rotor body as drum construction (Fig. 4a)

[0053] 12 open rotor construction (Fig. 4b)

[0054] 13 Rotor blade / rotor blade attachment

[0055] 14 Rotor blade attachment

[0056] M common drive motor in Fig. 2 to 11

[0057] G Gearbox

[0058] A first rotor area or rotor (inlet side)

[0059] B second rotor area or rotor (accept side)

[0060] Ak acceptance outlet

[0061] R Reject outlet

[0062] Z inlet

[0063] ZR inlet chamber

[0064] RS pulley arrangement (total)

[0065] Drive device for rotor A includes:

[0066] Engine A1 ,

[0067] Pulley A2

[0068] Drive shaft A3

[0069] Drive device for rotor B includes:

[0070] Engine B1

[0071] Pulley B2

[0072] Drive shaft B3 designed as a hollow shaft

Claims

Patent claims 1. Sorter, in particular a pressure sorter, with an inlet (Z) and at least one axially spaced-apart accept (Ak) and reject (R), with screening elements (2, 2') and a rotor (3) arranged radially spaced therefrom, which rotates in the inlet space (ZR) of the screening elements (2, 2') by means of a drive device, characterized in that the rotor (3) comprises at least two downstream rotor regions (A, B) in the axial direction between the inlet (Z) and accept (Ak), which rotate at different speeds and the rotor regions are each assigned to corresponding screening element regions (2A, 2B; 2'A, 2'B).

2. Sorter according to claim 1, characterized in that the rotor areas (A, B) rotate in the same direction.

3. Sorter according to claim 1, characterized in that the rotor areas (A, B) rotate in opposite directions (Fig. 3).

4. Sorter according to one of the preceding claims, characterized in that the inlet-side rotor region (A) rotates more slowly than the reject-side or downstream rotor region (B) (Fig. 2, Fig. 4).

5. Sorter according to claim 4, characterized in that the inlet-side rotor region (A) rotates 10% to 60%, preferably in a range of about 20% to 40%, slower than the reject-side or downstream rotor region (B).

6. Sorter according to one of the preceding claims, characterized in that the rotor regions (A, B) are substantially cylindrical.

7. Sorter according to one of claims 1-5, characterized in that the sieve elements (2, 2') are substantially cylindrical.

8. Sorter according to one of the preceding claims 1-5, characterized in that the rotor regions (A, B) are substantially conical (Fig. 11).

9. Sorter according to claim 8, characterized in that the sieve elements (2') are substantially conical (Fig. 11).

10. Sorter according to one of the preceding claims, characterized in that the sieve elements (2a) have different diameters (Fig. 6).

11. Sorter according to one of the preceding claims, characterized in that the rotor regions (A, B) have different diameters and cooperate appropriately with the sieve elements (2a) with different diameters (Fig. 6).

12. Sorter according to one of the preceding claims, characterized in that the rotor blades of the rotor regions (A, B) have a different distance from the wall of the sieve elements (2, 2', 2a).

13. Sorter according to one of the preceding claims, characterized in that the distance between the rotor blade (13) and the sieve element (2) is 1.5 mm to 10 mm, preferably 2.5 to 6.0 mm.

14. Sorter according to one of the preceding claims, characterized in that the rotor blades of the inlet-side rotor region (A) have a distance from the wall of the screen elements (2, 2', 2a) that is 0% to 30% smaller than the rotor blades of the reject-side or downstream rotor region (B) 15. Sorter according to one of claims 12 to 14, characterized in that the rotor blades (13) of the rotor regions (A, B) are arranged in front of the screening elements (A, B) in the inlet chamber (ZR).

16. Sorter according to one of the preceding claims, characterized in that the accept flow direction through the sieve element (A, B) is directed radially outwards (Fig. 1).

17. Sorter according to one of claims 1-15, characterized in that the accept flow direction through the sieve element (A,B) is directed radially inwards (Fig. 14).

18. Sorter according to one of the preceding claims, characterized in that the at least two sieve elements (A, B) are flowed through in different radial directions (Fig. 13).

19. Sorter according to one of the preceding claims, characterized in that the at least two rotor regions (A, B) are designed in the form of different rotor constructions (Fig. 4).

20. Sorter according to one of the preceding claims, characterized in that the rotor regions (B) comprise an open rotor construction (12), preferably for low-consistency applications, and a closed drum construction (10), preferably for high-consistency applications (Fig. 4).

21. Sorter according to one of the preceding claims, characterized in that a common inlet (Z) and at least two axially spaced, separate acceptance outlets (Ak1, Ak2) are assigned to the at least two rotor regions (A, B).

22. Sorter according to one of the preceding claims, characterized in that the drive device comprises a gear (G) with at least two shaft outputs for driving the rotor areas (A, B).

23. Sorter according to one of the preceding claims, characterized in that the drive device comprises at least two separate drives (Fig. 1).

24. Sorter according to claim 22, characterized in that the drive device comprises an axial hollow shaft (B3) for passing through the drive shaft for the respective other rotor region (B, A).

25. Sorter according to one of the preceding claims, characterized in that a drive (A1) is provided on the top of the sorter (S10) and / or on the bottom of the sorter (S10) (Fig. 10, Fig. 11).

26. Sorter according to one of the preceding claims, characterized in that in a design with more than two spaced-apart rotor regions (A to F), these rotate at different speeds and / or have different directions of rotation (Fig. 9).

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