EP0764736B1 - Foil for screening apparatus - Google Patents

Abstract

A rotor blade for a sieve, esp. for fibrous material suspensions in paper pulping, has an outer contour facing a sieve wall which interacts with the sieve wall so that it generates, in the direction of flow of the stock, a suction zone section (C) with increasing blade width and a pressure zone section (D) with decreasing blade width. The total length (Fl) of the blade (5) is composed of the length of the suction zone section (C) and the length (L1) of the pressure zone section (D), and the outer contour of the blade has a smooth profile from the section of increasing blade width to that of decreasing width, even at the transition point. The length (L1) of the blade in the pressure zone section (D) is about 0.1 - 0.45 x F1.

Description

The invention relates to a wing and an arrangement of several wings for sorting devices, in particular are intended for fiber suspensions in paper pulping. In particular, the invention relates to preferred wing shapes.

From EP-A-0 275 921, for example, a wing or a Sorting wing of a sorter with a drum-like body known. In the meridian section, the wing points in the direction of rotation ever increasing cross section and ends in one steep edge, and this is included in the direction of rotation Extension with a decreasing cross-section with a Fillet. The area with increasing cross section forms in Interaction with a surrounding the drum-like body Sieve wall a suction zone, and the area with decreasing Cross section forms in cooperation with the screen wall Pressure zone. The outer contour of the wing includes a steep one falling edge at the transition between the area with increasing Cross section and the area with decreasing cross section. By the sudden change in direction caused by this can in Area of the pressure zone Contamination from the perforations the screen wall are pressed, so that a reduced sorting quality of the sorter is to be expected. By profiling the The flow of material is directly on the perforations directed so that a high hydraulic load occurs, which the risk of easy relocation of the Sorter. Caused by the fillet and the sudden change of direction causes strong pulsations, which lead to turbulence in the fabric area, whereby it especially with increasing material density to fiber accumulations the sorting wing can come. This can cause malfunctions of the sorter in particular if the Clogged screen area. Because of the sharp edge between the increasing cross-sectional area and decreasing cross-sectional area there is also a relatively high flow resistance through the wing in the fabric flow area so that this sorter with must work according to suitable, relatively high speeds, which have a relatively high energy consumption during operation Have consequence.

From US-A-4 676 903 there is a screening device for fiber pulp known, which has a rotating element, which a Has outer contour surface with recesses. The recesses are from a first plane parallel to the lateral surface, one inclined plane, an upper plane and a side plane educated. The side plane is essentially perpendicular to first level. Here too you get a steeply sloping edge between the pressure zone and the suction zone with the rotor rotating. Therefore, essentially the same difficulties arise and disadvantages as in EP-A-0 275 921. The above Areas can be sloping through the steep Edges form fiber bundles and braids, which lead to malfunctions the sorting device and / or a decrease in efficiency lead in the sorting process. There will also be a wing described, which is designed such that a pressure pulse from the leading surface of the wing with a maximum at the narrowest point to the strainer basket is generated. According to this state of the Technology should have a long and lasting pressure pulse be generated. This results in pressure pulsations, which are undesirable.

From the magazine "Wochenblatt für Papierfabrikation" 17 ,, 1988, pages 733 - 737, the article by D. Egelhof "Der low-pulsation vertical classifiers - basics, development, Results "show that by optimizing the wing shape damping the pressure vibrations emanating from the vertical classifier can achieve. Details regarding such Optimization methods are not included there. It will only on the arrangement of the blades on the rotor body, thereby reducing pressure vibrations should.

DE 28 30 386 C2, WO90 / 05807 and US-A-2 835 173 are sorting devices known, which have a rotor that on its outer circumference Cleaning elements or sorting elements is occupied. By the The above installation of the same can also be fiber bundles and braids as well as dead zones and spinning due to the Form the disruptive effect of the cleaning elements in the material flow area. The Annular gap between the screen wall and the rotor base body due to the projecting height of the cleaning elements or Driving elements narrowed. If between the highest point of the Cleaning element and the sieve wall surface only a small one If there is a distance, the goods to be treated can be on this very narrowed, annular gap a very strong Experience thickening. This leads to malfunctions of the Sorter. However, if you arrange such a rotor at a greater distance from the screen wall, so you have to Increase the speed of the rotor, reducing the energy consumption of the Sorting device becomes larger.

There is therefore a need for wing-shaped cleaning elements for sorting devices which keep the Sieving of impurities, avoiding thickening effects, avoidance of pulsations and sufficient Fluidization of the material to be sorted (the fiber) mainly caused by turbulence.

The invention aims to achieve the one outlined above Need to take into account and especially while overcoming of the difficulties described above wings for sorting devices to provide, especially for fiber suspensions are determined when digesting paper and which in supportive An efficient and reliable manner high quality sorting with an energy saving Allow operation.

For this purpose, according to the invention, a wing for sorting device, especially for fiber suspensions in paper pulping, provided which faces such a screen wall Outside contour has that in cooperation with the screen wall in Flow direction a suction zone section with increasing Wing width and a pressure zone section with decreasing Wing width forms, whereby the total length of the wing the length of the suction zone section and the length of the pressure zone section composed. Such a wing is traced the invention in that the screen facing outer contour of the Wing a steady course of increasing wing width and has decreasing wing width also at the transition area, as well as the Length (L1) of the wing in the pressure zone section approximately L1 = 0.1 to Is 0.45x Fl (total wing length).

The wing according to the invention thus has to face the screen Outside contour profiling without edges, breaks or Fillets, but with both the section of the wing increasing wing width as well as the section of the wing decreasing wing width and also the transition area a steady course. This is also in the area of the pressure zone section a steady increase in pressure due to the steady course available, which ensures gentle transport of material to the perforations the screen wall takes place. This prevents Contamination in the pressure zone section due to the perforations the screen wall to be pressed. So you get an improved one Sorting quality. At the same time, you also get the necessary ones Turbulence to keep and clean the perforations as well sufficient fluidization of the goods to be sorted due to the change in sash width in the suction zone section. On the other hand, pulsations and related ones can be avoided Impact effects due to the constant curve in the suction zone section prevent so that you have a more efficient flow of material to increase the efficiency of the sorting process. Also can by the shape of the outer contour of the wing of the Reduce its own flow resistance in the material flow area, so that not only the sorting process becomes more efficient can be carried out, but also an energy-saving way of working a sorting device equipped with such wings is obtained because the same throughputs Let the rotor speed down and therefore cheaper Power consumption values when operating the sorting device receives.

Thanks to the wing designed according to the invention, the sorting device especially suitable for sorting tasks in High consistency area, as well as for sorting tasks with quite coarse impurities, since the sorting quality can significantly improve. By reducing the pulsations due to the continuous course of the outer contour damage and malfunctions in subsequent process steps avoided and the strain on the sieve walls caused by sieve baskets can be formed can be reduced.

• Die Länge L1 des Flügels im Druckzonenabschnitt, welche etwa L1 = 0,1 - 0,45 x Fl (Gesamtflügellänge), vorzugsweise etwa L1 = 0,3 x Fl, beträgt;
• der Flügel im Druckzonenabschnitt einen Radius R2 hat, welcher etwa R2 = 0,3 - 0,6 x Fl, vorzugsweise R2 = 0,4 - 0,5 x Fl beträgt;
• das vorauslaufende Ende des Flügels im Saugzonenabschnitt mit einem Radius R3 ausläuft, welcher in der Größenordnung von 3 - 25 mm, vorzugsweise 6 bis 20 mm liegt.

The following influencing variables with regard to the wing geometry have proven to be particularly expedient with regard to the different tasks of such wings in the region of the pressure zone:

• The length L1 of the wing in the pressure zone section, which is approximately L1 = 0.1-0.45 x Fl (total wing length), preferably approximately L1 = 0.3 x Fl;
• the wing in the pressure zone section has a radius R2 which is approximately R2 = 0.3-0.6 x Fl, preferably R2 = 0.4-0.5 x Fl;
• the leading end of the wing ends in the suction zone section with a radius R3 which is of the order of 3 to 25 mm, preferably 6 to 20 mm.

• Der Flügel hat im Saugzonenabschnitt einen Radius R1, welcher etwa R1 = 0,8 - 1,5 x Fl, vorzugsweise 0,9 - 1,4 x Fl beträgt;
• das nachlaufende Ende des Flügels weist vorzugsweise einen Radius R4 in der Größenordnung von 1 bis 5 mm, vorzugsweise 1,5 bis 3 mm auf.

In the area of the suction zone section, the following influencing factors have proven to be expedient and essential with regard to optimizing the functioning:

• The wing has a radius R1 in the suction zone section, which is approximately R1 = 0.8-1.5 x Fl, preferably 0.9-1.4 x Fl;
• the trailing end of the wing preferably has a radius R4 on the order of 1 to 5 mm, preferably 1.5 to 3 mm.

The total length Fl des are further influencing variables Wing, based on the inside diameter of the screen, as well as the largest Wing width Fb to mention. The total length Fl, based on the Sieve inner diameter Di, is about the order of 0.05 to 0.3 x Di, preferably from 0.08 to 0.2 x Di. The largest Wing width Fb is approximately Fb = 0.15-0.35 x Fl, preferably Fb = 0.2 - 0.27 x Fl.

If the above preferred ranges of the specified Sizes in the shape of the wing and especially the The design of the outer contour facing the screen was observed pressure pulsations can be avoided and you achieve a reduction in power consumption, since the wing width and the leading wing radius in the area of the pressure zone section as slim a shape of the wing as possible.

With regard to the entry area of the paper stock one obtains when adhering to these values that the paper stock is gentle too the perforations of the screen wall is guided. Because in the area of Pressure zone, a steady rise in pressure is generated Prevent contaminants from pressing through, which actually to be separated. Furthermore, this section is also dimensioned so that it with a view to avoiding thickening effects doesn't get too long.

Thanks to the order of magnitude for the influencing variables of the wing in the Suction zone section has such a sufficient length that reliable cleaning of the perforations of the screen wall is guaranteed. If the suction zone section is too short, the current breaks off too soon and turbulence occurs, which affect the cleaning effect.

In particular, due to the gentle handling of the fabric close cooperation with the screen wall Screen wall, even if it is contoured, for example, so that a higher throughput is achieved. Furthermore, the Reduce rotor speed so that you save energy can achieve.

Preferably, the smallest distance s between the Outer contour of the wing and the sieve wall about 0.5 to 10 mm, preferably 1.5 to 6 mm. Such a distance is essential smaller than with conventional designs of such sorters, so that you can get very high quality sorting results without Can cause malfunctions. The rotor speed can also be changed lower because the wings are reduced due to the Distance very effectively with regard to the fabric flow area the cleaning and fabric management act.

With regard to the side of the wing facing away from the screen, which at a freely projecting wing also influences the If the sorting device works, it can be turned away from the screen Page designed so that they are essentially with the shape of the screen-facing outer contour according to the the above explanations. You then get one symmetrical design of the wing. Alternatively, the screen facing away Side of the wing deviates from the screen facing Be designed outer contour. For example, the one facing away from the screen Side be formed as a straight section.

In particular, the wing is aerodynamically profiled. This can reduce the wing's inherent flow resistance and the energy consumption can continue to reduce. This also allows interference flows in the Suppress fabric flow area to reduce the fabric flow both on the Favor cleaning side as well as on the fabric feed side.

If necessary, the wing can be designed in several parts. If he Wing is designed in one piece or in several parts, depends on essentially on the size of the wing and its function and arrangement, for example on a base body.

Preferably, the section with increasing wing width and the section with decreasing wing width in the fabric flow direction or point against it. So you can be independent of the relative direction of movement between screen wall and wing with the wing according to the invention, the desired effects generate on the fabric flow.

With regard to the arrangement of the wing or possibly several Wings have different options. So the wing can for example directly on the outer circumference of a base body, such as a basic rotor body, preferably essentially one cylindrical or conical rotor body, attached or be formed in one piece with the base body, or optionally attached to the base body by means of a support arm his. If the wing on the outer circumference of the main body attached and fastened there, so the attachment by welding or soldering, or it can be screwed on become. If the wing or wings directly on the Mounted on the outer circumference of the basic rotor body and fastened there there are no protruding internals, so that dead zones, Avoid spinning, braid formation or the like. This allows the operational safety of a sorting device improve with the wings of the invention. Through the Avoiding the above internals can also Intrinsic flow resistance of the arrangement in the material flow area belittling so that you're not just a more efficient way of working the sorting device, but also an energy-saving one Operation.

With the respective mounting method of the wing on the base body spacers such as shims or the like, are provided, by means of which the distance between the next point of the outer contour of the wing and the screen wall change and vary. This can fine tune to the respective sorting task.

Furthermore, the wing can face the generatrix of the base body be arranged inclined. This can create transition areas between individual sorting levels.

To improve the operation of the wing, this can opposite the tangent to the base body at an angle be employed, which is up to 10 °, or preferably up to 4 °, can be.

Furthermore, an arrangement is specified according to the invention, which comprises several wings, which is characterized in that the Wing in different basic body axial planes in the circumferential direction are staggered. This gives you one Wing arrangement for a sorting device, by means of which a Matching the effect of the wings on the respective sorting levels assigned sorting tasks can be done without a noticeable mutual influence is to be feared.

In summary, the invention relates to the design and Profiling of wings in sorting devices for fiber suspensions, especially for pulping paper, which such are optimized and chosen so that you have a streamlined Profiling the outer contour of the wing or wings without sharp Edges. This reduces the inherent resistance, and you get a significant energy saving. Further can through the section with ever increasing wing width and the section with continuously decreasing wing width, whereby both sections also merge continuously, on the one hand a suction zone in cooperation with the screen wall facing are formed, which for effective sieve cleaning provides sufficient suction, and on the other hand a Pressure zone are formed, which is a gentle material transport to the perforations of the screen wall without a sudden increase in pressure allowed. This makes the sorting quality essential improve.

Fig. 1

einen schematischen Ausschnitt einer Draufsicht auf eine Anordnung umfassend einen Flügel und eine zugeordnete Siebwand bei einer Sortiervorrichtung, und

Fig. 2

einen schematischen Ausschnitt einer Draufsicht auf eine Ausführungsform mit mehreren Flügeln auf dem Außenumfang eines Grundkörpers, insbesondere eines Rotorgrundkörpers.

The invention is explained below with reference to preferred embodiments with reference to the accompanying drawings. It shows:

Fig. 1

a schematic section of a plan view of an arrangement comprising a wing and an associated screen wall in a sorting device, and

Fig. 2

a schematic section of a plan view of an embodiment with several blades on the outer circumference of a base body, in particular a rotor base body.

In the figures of the drawing the same or similar parts are with provided the same reference numerals.

The essential influencing factors in the Design of a wing 5 schematically associated with one Sieve 2 explains which perforations 3 in its sieve wall 2a Has. The inside diameter of the sieve 2 is excerpted indicated with Di. The wing 5 is without the clarification of details of an attachment of the same and of illustrated further details of a sorting device, since such a wing 5 in sorters with different Operating principles and different rotor types with im essential same or similar advantages are used can. Since it also only relies on the relative movement between the Screen wall 2a and the outer contour of the wing 5 arrives at The explanations below only refer to the direction of flow of the material detailed, which is shown schematically with an arrow is. The direction of the material flow can of course also be against direction of the arrow shown. Even if in Counter direction of the material flow direction according to Figure 1 slightly result in different modes of action, so the Design of wing 5 to the essential tasks, after which hereby keep the screen 2 free of impurities thickening effects should be avoided, Pulsations should be avoided and adequate fluidization of the goods to be sorted due to the generation of turbulence should be achieved.

The wing 5 has an overall outer contour 6, which the Screen wall 2a facing, which has such a course, that in cooperation with the sieve wall 2a in the material flow direction (see arrow in Figures 1 and 2) a suction zone section C with increasing wing width and a pressure zone section D with decreasing wing width is formed. The suction zone itself is with P- and the pressure zone with P +. The wing 5 has one Total wing length Fl, which is equal to the sum of the length L1 of the Suction zone section C and the length L2 of the pressure zone section D is. The total wing length Fl is preferably based on the Dimension the inner diameter Di of the sieve 2 such that Fl = 0.05 is up to 0.3 x Di, and preferably Fl = 0.08 to 0.2 x Di. The length L1 of the pressure zone section D is 0.1 to 0.45 x Fl (total wing length) and preferably to 0.3 x Fl. The largest wing width is designated with Fb. This will be between the side of wing 5 facing away from the screen and the highest point measured on the outer contour 6 of the wing 5. The largest Wing width Fb is, for example, in a range of Fb = 0.15 - 0.35 x Fl, and in particular Fb = 0.2 to 0.27 x Fl. in the Pressure zone section D becomes the outer contour 6 of the wing 5 preferably from a segment of a circle with a radius R2 educated. The radius R2 is approximately in a range of R2 = 0.3 - 0.6 x Fl, and preferably from R2 = 0.4 to 0.5 x Fl. The leading end of the wing 5 is preferably one immediately adjacent circular section formed or runs out with a radius R3, which is in a range of 3 to 25 mm, in particular from 6 to 20 mm.

The outer contour 6 of the wing 5 in the suction zone section C is preferably formed by a segment of a circle, which one Has radius R1. R1 is on the order of R1 = 0.8 to 1.5 x Fl, and in particular from R1 = 0.9 to 1.4 x Fl. At the beginning of Suction zone section C, that is, at the trailing end of the Outer contour 6 may have a radius R4 which is in one Range of 1 to 5 mm, preferably in a range of 1.5 to 3 mm.

The smallest distance between the screen wall 2a and the outer contour 6 is denoted by s. This distance s can be in a range from 0.5 to 10 mm, preferably from about 1.5 to about 6 mm lie.

As is shown schematically in FIG. 1, there may be a deviation from the illustrated embodiment, in which the screen remote Side of the wing 5 approximately perpendicular to the not shown Center axis of the sorting device is arranged below an angle of attack FW can be arranged, which in one area of up to 10 °, preferably up to 4 °. At this schematically indicated at the angle of attack FW arrangement of Wing 5 is this opposite the tangent to a base body, for example a rotor base body (see reference number 1 in Figure 2) then employed including the angle of attack FW.

The wing 5, which is also referred to as a hydrofoil, enables interaction with perforations 3 in the sieve 2 regardless of the profiling of the perforations on the manner described in more detail below.

In the area of the suction zone P- (suction zone section C in the figures) turbulence in the area of the perforations 3 to keep clear and cleaning as well as for feeding the material through the perforations 3 generated. Due to the increasing wing width in the suction zone section C is a gentle mass transfer to the in Perforation nearest fabric flow direction 3. Starting from the Place with the largest wing width is then also a constant pressure build-up in the pressure zone section D, so that in more efficiently in the pressure zone P + the fabric through the Perforations 3 is promoted. Since one is particularly in the area the pressure zone P + a steady pressure increase due to the steady Course of the outer contour 6 of the wing 5 to the smallest Receives distance s, the sorting quality can be improved since for example, preventing contamination by a sudden pressure increase through the perforations 3 pressed become. By the more efficient mode of action, achieved by the Profiling of the wing 5 according to the type described above and the streamlined profile of the outer contour 6, can the energy consumption of the assigned sorting device decrease. Due to the streamlined profile of the Wing 5, the inherent resistance of the same can be reduced, and there are dead zones, spinning, braids and the like avoiding either a degradation of the efficiency of the sorting device or can even lead to malfunctions and the perforations 3 can clog. Since the suction zone section C and the Pressure zone section D without interruption with a steady Transition into each other, pulsations can be reduced, which have led to the sieve 2 strong Exposures, especially changing loads, exposed was. Thus, the wing 5 allows a efficient sorting process with high quality results as well as an energy-saving, reliable operation an assigned sorting device.

FIG. 2 shows a preferred embodiment of a sorting device shown schematically and by way of example. With this For example, the sorting device has a rotor with a Rotor base body 1, which is, for example, corresponding to the Direction of material flow (see arrow) in Figure 2 clockwise rotates. The basic rotor body 1 can be essentially cylindrical or be conical or frustoconical. The Rotor base body 1 is surrounded by the screen 2, which the Sieve wall 2a forms which perforations 3, such as openings, Slots or the like. Although not shown in more detail is the profile geometry of the perforations 3, for example be chosen in the manner shown in US-A-5,073,254. The screen openings shown there open into groove-shaped grooves, which are essentially transverse to the direction of flow Extend fiber suspension. The grooves are curved in an arc and have a downstream flank with a stronger one Curvature as well as an upstream flank with weaker Curvature, with the flanks bump-free through an arc can be connected. On an outer circumference 4 of the Rotor base body 1 are in the example shown, in Circumferentially spaced wings 5 placed and, as there shown, for example by means of welding or soldering the rotor base body 1 firmly connected.

In deviation from the connection shown of wing 5 and Base body 1 can also be selected a screw connection, or if necessary, the wings 5 by means of support arms on Base body 1 be attached. If necessary, spacers, such as shims or the like, in addition to Attachment of the wing 5 to the rotor base body 1 used be, if necessary, the smallest distance s between the Screen wall 2a and the outer contour 6 of the wing 5 to vary and to adjust to the size ranges mentioned above.

Although not shown, the base body 1 can with the fixed wings 5 are fixed at the sorting device, and the sieve 2 can move around the common central axis turn the arrangement of sieve 2 and base body 1.

Furthermore, the wings 5 on different axial planes of the Base body 1 are arranged. Each wing 5 can for example inclined with respect to the generatrix of the base body 1 be arranged. The wings 5 are preferably different Axial planes of the base body 1 offset relative to one another arranged.

Furthermore, one obtains an identical or similar mode of action and same or similar advantages if either the direction of rotation of the basic rotor body 1 compared to that illustrated in FIG is reversed, or if you look at the relative movement a direction of material flow between the wings 5 and the screen 2 receives, which is opposite to that represented by the arrow is directed.

Of course, the profile of the wing 5 is not on the Hand explained the preferred embodiments shown Details are limited but there are numerous changes and modifications possible, which the specialist in case of need will meet without leaving the inventive concept.

LIST OF REFERENCE NUMBERS

1

cylindrical rotor body

2

scree

3

perforations

4

Outer circumference of the cylindrical rotor body 1

5

sorting wings

6

Outside contour of the wing 5

S

next point

s

distance

FW

angle of attack

C

area increasing in cross section

D

area decreasing in cross section

P +

pressure zone

P-

suction zone

F1

Total leaf length

L1

Leaf length of the pressure zone section D

L2

Leaf length of the suction zone section C

Fb

leaf width

Claims (21)

1. Vane for sorting devices, in particular for fibrous suspensions during paper pulping, which has such an outer contour facing a screen wall that, in cooperation with the screen wall in stock flow direction, it forms a suction zone section (C) having increasing vane width and a pressure zone section (D) having decreasing vane width, wherein the total length (Fl) of the vane (5) is composed of the length of the suction zone section (C) and the length (L1) of the pressure zone section (D), and the outer contour (6) of the vane (5) facing the screen has a continuous pattern of increasing vane width and decreasing vane width even at the transition region, characterised in that the length (L1) of the vane (5) in the pressure zone section (D) is approximately L1 = 0.1 to 0.45 x Fl (total vane length), the length (L1) of the vane (5) in the pressure zone section (D) is approximately L1 = 0.1 to 0.45 x Fl (total vane length) approximately L1 = 0.3 x Fl, the vane (5) in the suction zone section (C) has a radius (R1) of approximately R1 = 0.8 to 1.5 x Fl, preferably R1 = 0.9 to 1.4 x Fl, and in that the greatest vane width (Fb) is approximately Fb = 0.15 to 0.35 x Fl, preferably Fb = 0.2 to 0.27 x Fl.
2. Vane according to claim 1, characterised in that the vane (5) in the pressure zone section (D) has a radius (R2) of approximately R2 = 0.3 to 0.6 x Fl, preferably R2 = 0.4 to 0.5 x Fl.
3. Vane according to claim 1 or 2, characterised in that the total length (Fl) of the vane (5) based on the screen internal diameter (Di) lies approximately in the order of magnitude of Fl = 0.05 to 0.3 x Di, preferably Fl = 0.08 to 0.2 x Di.
4. Vane according to one of the preceding claims, characterised in that the section of the vane (5) having decreasing vane width tapers with a radius (R3) in the order of magnitude of 3 to 25 mm, preferably 6 to 20 mm.
5. Vane according to one of the preceding claims, characterised in that the section of the vane (5) having increasing vane width starts with a radius (R4) in the order of magnitude of 1 to 5 mm, preferably 1.5 to 3 mm.
6. Vane according to one of the preceding claims, characterised in that the smallest distance (s) between the outer contour (6) of the vane (5) and the screen wall (2a) is approximately 0.5 to 10 mm, preferably 1.5 to 6 mm.
7. Vane according to one of the preceding claims, characterised in that the side of the vane (5) facing away from the screen corresponds essentially to the shape of the outer contour (6) facing the screen.
8. Vane according to one of claims 1 to 6, characterised in that the side of the vane (5) facing away from the screen is designed to be different from the outer contour (6) facing the screen.
9. Vane according to one of the preceding claims, characterised in that it is profiled to be favourable to flow.
10. Vane according to one of the preceding claims, characterised in that it is designed to have multiple parts.
11. Vane according to one of the preceding claims, characterised in that the section (C) having increasing vane width and the section (D) having decreasing vane width point in stock flow direction or contrary to the same.
12. Vane according to one of the preceding claims, characterised in that it is designed to be attached to an outer periphery (4) of base body (1) or to be integral with the base body (1).
13. Vane according to claim 12, characterised in that the base body (1) is a rotor base body, preferably an essentially cylindrical or conical rotor base body.
14. Vane according to claim 12 or 13, characterised in that it is inclined with respect to the generatrix of the base body (1).
15. Vane according to one of claims 12 to 14, characterised in that it is set at an angle (FW) of up to 10°, preferably up to 4°, with respect to the tangent at the base body (1).
16. Vane according to one of the preceding claims, characterised in that it is placed on and attached directly to the outer periphery (4) of the base body (1).
17. Vane according to claim 16, characterised in that it is welded-on or soldered-on.
18. Vane according to one of claims 12 to 15, characterised in that it is attached to the base body (1) by means of a supporting arm.
19. Vane according to one of claims 12 to 18, characterised in that it is screwed onto the base body (1) or by means of the supporting arm.
20. Vane according to claim 19, characterised in that spacers, such as shim plates or the like, are provided to alter the smallest distance (s) between the outer contour (6) of the vane (5) and the screen wall (2a).
21. Arrangement comprising several vanes according to one of claims 12 to 20, characterised in that the vanes (5) are arranged to be offset peripherally in different axial planes of the base body.

Images