SEPARATOR

Abstract

A separator having a housing, a feed cone and a rotatable dispersing plate, on the upper face of which dispersing blades which are distributed across the periphery of the dispersing plate are arranged. The feed cone is arranged on the housing at a distance from the dispersing plate. The precision of the separator is improved compared to conventional separators.

Claims

1. A separator, comprising: a housing, a feed cone, and a rotatable dispersing plate, on an upper face of which dispersing blades which are distributed across a periphery of the dispersing plate are arranged, wherein the feed cone is arranged on the housing at a distance from the dispersing plate.

2. The separator as claimed in claim 1, wherein the feed cone has an aperture angle of 4590.

3. The separator as claimed in claim 1, wherein the feed cone at its cone edge has a radius R.sub.1 for which: 0.5R.sub.2<R.sub.1<R.sub.2, where R.sub.2 denotes the radius of the dispersing plate.

4. The separator as claimed in claim 3, wherein a radius R.sub.3 of an inner circumference of the dispersing blades is R.sub.3R.sub.1.

5. The separator as claimed in claim 2, wherein a distance A.sub.1 between the cone edge of the feed cone and the dispersing blades of the dispersing plate is 0<A.sub.130 mm.

6. The separator as claimed in claim 1, wherein each dispersing vane has a dispersing surface which is situated perpendicular to the rotation direction of the dispersing plate.

7. The separator as claimed in claim 1, wherein the dispersing blades are plates sticking up from the upper face of the dispersing plate and extending in the radial direction.

8. The separator as claimed in claim 1, wherein there is provided on the housing an impact ring, having impact elements distributed over the inner circumference and projecting in the direction of the dispersing plate.

9. The separator as claimed in claim 8, wherein a distance A.sub.2 between the impact elements and the dispersing plate is 0<A.sub.230 mm.

10. The separator as claimed in claim 8, wherein the impact elements are configured and arranged such that they lie opposite at least the dispersing blades.

11. The separator as claimed in claim 1, wherein the separator comprises a separator wheel having separator wheel paddles and an air guidance system having guide vanes for the supply of separating air, while an annular separating space is arranged between the separator wheel and the air guidance system.

12. The separator as claimed in claim 11, wherein the guide vanes are guide plates protruding into the separating space and extending in a vertical direction.

13. A separator, comprising: a separator wheel having separator wheel paddles and an air guidance system having guide vanes for the supply of separating air, while an annular separating space is arranged between the separator wheel and the air guidance system, wherein the guide vanes are guide plates protruding into the separating space and extending in a vertical direction.

14. The separator as claimed in claim 13, wherein the dispersing plate is fastened to the separator wheel.

15. The separator as claimed in claim 13, wherein the air guidance system has air windows and a guide plate is arranged on at least one edge of the air windows.

16. The separator as claimed in claim 15, wherein guide plates are arranged on opposite edges of the air windows.

17. The separator as claimed in claim 16, wherein the guide plates are arranged between two respective air windows such that their ends converge on each other.

18. The separator as claimed in claim 16, wherein the two respective guide plates which are arranged at each air window are oriented parallel to each other.

19. The separator as claimed in claim 13, wherein the guide plates make an angle of attack with the radius R.sub.L of the air guidance system of 3060.

20. The separator as claimed in claim 15, wherein the guide plates are curved in the direction of the separator wheel.

21. The separator as claimed in claim 20, wherein the guide plates have a single radius of curvature R.sub.4.

22. The separator as claimed in claim 20, wherein the guide plates are curved such that a radius of curvature R.sub.4 decreases in the direction of the separator wheel.

23. The separator as claimed in claim 21, wherein the radius of curvature R.sub.4 is 5 mmR.sub.42000 mm.

24. The separator as claimed in claim 13, wherein the air guidance system has at least one cone ring with a particle guide element protruding into the separating space and having a first conical surface.

25. The separator as claimed in claim 24, wherein the first conical surface is arranged on the upper face of the particle guide element and forms an angle with a vertical axis L.sub.V of 10<<90.

26. The separator as claimed in claim 13, wherein a distance A.sub.4 between an inner circumference of the air guidance system and an outer circumference of the separator wheel is
A.sub.4=.Math.D.sub.S(V1) where V=D.sub.L/D.sub.S with 1.01V1.2 and Ds denotes an outer diameter of the separator wheel and D.sub.L an inner diameter of the air guidance system.

27. The separator as claimed in claim 26, wherein the ratio V=D.sub.L/D.sub.S is 1.05V1.1.

28. The separator as claimed in claim 24, wherein a distance A.sub.3 from the inner edge of the particle guide elements and/or ends of guide plates to an inner circumference of the separator wheel is:
0.005.Math.A.sub.4A.sub.30.5.Math.A.sub.4.

29. The separator as claimed in claim 13, wherein the air guidance system has at least one circumferential horizontal air slot.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0063] Sample embodiments of the invention are explained more closely below with the aid of schematic drawings. These show:

[0064] FIG. 1, a separator in vertical cross section,

[0065] FIG. 2, a vertical cross section through the upper region of the separator shown in perspective view,

[0066] FIG. 3, a top view of the separator,

[0067] FIG. 4, a vertical cross section through cone and dispersing plate of the separator of FIG. 1,

[0068] FIG. 5, a cutout from FIG. 4 in enlarged representation,

[0069] FIG. 6, a horizontal cross section through a separator wheel and an air guidance system according to one embodiment,

[0070] FIG. 7, a perspective representation of an air guidance system according to another embodiment,

[0071] FIG. 8a, a top view of the air guidance system shown in FIG. 7 with separator wheel drawn in,

[0072] FIGS. 8b, c, a top view of an air guidance system with separator wheel according to two embodiments with curved guide plates,

[0073] FIG. 9, an enlarged cutout from FIG. 8a,

[0074] FIG. 10, another embodiment of an air guidance system with separator wheel in top view,

[0075] FIG. 11, a cross section through an air guidance system according to another embodiment with a cone ring,

[0076] FIG. 12, a cross section through a cone ring shown in FIG. 11,

[0077] FIG. 13, an enlarged vertical cross section through the air guidance system and a corresponding separator wheel, and

[0078] FIG. 14, a diagram of the cumulative distribution curves Q.sub.3 to explain the yield and separating efficiency of the separator.

DETAILED DESCRIPTION OF THE INVENTION

[0079] FIG. 1 shows a separator 1 in vertical cross section. The separator 1 comprises a housing 2, having a fill pipe 6 and divided into an upper housing portion 3 and a lower housing portion 5. In the upper housing portion 3, which is substantially cylindrically shaped, there is situated a separator wheel 60 with separator wheel paddles 62 as well as an air guidance system 70 with three guide vane rings 72. Between the separator wheel 80 and the air guidance system 70 there is located the separating space 18. On the separator wheel 60 there is fastened a dispersing plate 30, which is thereby driven by the separator wheel 60.

[0080] The dispersing plate 30 has dispersing blades 40 on its upper face 31 (see also FIG. 2) in the marginal region, consisting of substantially rectangular metal plates sticking up from the upper face 31 of the dispersing plate 30 and extending as far as the rim 33 of the dispersing plate 30. By means of the dispersing plate, a feed cone 20 is fixed stationary to the housing 2.

[0081] The upper housing portion 3 comprises a separator cover 4, in which the fill pipe 6 with the fill opening 7 for the feeding material is disposed. The feeding material is filled in through the fill pipe 6 into the separator 1 and strikes against the feed cone 20 there.

[0082] In the lower housing portion 5 there is arranged the drive shaft 13 for the separator wheel 60, which is driven at the lower end by a drive mechanism 12. The lower housing portion 5 moreover comprises an outlet pipe with the outlet opening 9 for discharging the fines. At the lower end of the conical lower housing portion 5 there is arranged a suction fan 11 and the outlet 10 for coarse material.

[0083] FIG. 2 shows a detail cross section through the upper region of the housing 3.

[0084] The feed cone 20 protrudes by its cone apex 26 into the fill pipe 6 and is secured there by means of a fastening element 22 to the fill pipe 6.

[0085] The dispersing plate 30 is surrounded by an impact ring 50, having impact elements 54 on its inner surface 52, which stick out from the inner surface 52 in the direction of the dispersing plate 30. The impact elements 54 are arranged distributed over the inner surface 52 of the impact ring 50 and extend in the vertical direction at least for the entire height of the dispersing blade 40. The impact ring 50 is adjoined at the top by a conical wall 58.

[0086] The separator wheel 60 situated beneath the dispersing plate 30 has a plurality of vertically disposed separator wheel paddles 62 and is surrounded by an air guidance system 70 with a total of three guide vane rings 72.

[0087] FIG. 3 shows a top view of the separator 1 shown in FIG. 1, having two separating air feeds 8a, b arranged tangentially on the housing portion 3. A total of twenty four impact elements 54 are arranged on the impact ring 50. The impact elements 54 are arranged at a spacing from the dispersing plate 30. The dispersing plate 30 carries on its upper face 31 six dispersing blades 40, which extend in part to beneath the feed cone 20. The inner circumference of the dispersing blades 40 is indicated by the dashed circular line 44, on which the inner surfaces 41 of the dispersing blades 40 lie. The corresponding radius R.sub.3 of the inner circumference 44 of the dispersing blades 40 is likewise indicated, as is the radius R1 of the cone edge 24 of the feed cone 20.

[0088] FIGS. 4 and 5 show enlarged cross sectional representations of the upper portion of the separator 1 shown in FIG. 2. The feed cone 20 has an aperture angle of around 85. The feed cone 20 extends as far as the region of the dispersing blades 40, so that feeding material 14 introduced from above through the fill pipe 6 is taken directly to the dispersing blades 40. The agglomerates in the feeding material 14 are indicated by the reference number 15. The agglomerates 15 as well as the other particles of the feeding material 14 are first caught up by the dispersing surface 46 of the dispersing blades 40, before striking onto the upper face 31 of the dispersing plate 30.

[0089] Because of the centrifugal forces acting on the particles of the feeding material 14, the particles are flung in the direction of the impact ring 50, where they strike against the impact elements 54. The radii R.sub.1, R.sub.2 and R.sub.3 are drawn in, showing that the radius R.sub.3 is smaller than the radius R.sub.1, and preferably for the radii 0.4R.sub.2R.sub.30.8R.sub.2. This ensures that the agglomerates 15 of the feeding material 14 upon leaving the feed cone 20 do not shoot out beyond the rim 33 of the dispersing plate 30 without hitting the dispersing blades 40.

[0090] This situation can be seen more clearly in a further enlarged representation of FIG. 5.

[0091] FIG. 5 shows the distance A1 between the cone edge of the feed cone 20 and the top surface 43 of the dispersing vane 40. Moreover, the distance A.sub.2 between the edge surface 34 of the dispersing plate and the impact element 56 is drawn in. The outer surface 42 of the dispersing vane 40 is set back from the edge surface 34 of the dispersing plate 30.

[0092] The impact element 54 extends to beneath the plane in which the bottom side 32 of the dispersing plate 30 lies. The length L.sub.S of the dispersing blade 40 is preferably in the range of 0.02R.sub.2L.sub.S0.2R.sub.2. The height H.sub.S is preferably in the range of 0.01R.sub.2H.sub.S0.1R.sub.2.

[0093] In the embodiment shown here, A.sub.1R.sub.2/6. Preferably A.sub.1<R.sub.2/2.

[0094] For the height H.sub.P of the impact elements 54 preferably 0.03R.sub.2H.sub.P0.5R.sub.2. The width B.sub.P of the impact element 54 is somewhat less than the height H.sub.S of the dispersing vane 40.

[0095] As a representative of the agglomerates, there is shown an agglomerate particle 15 which is sliding down along the conical surface and which is caught up by the dispersing surface 46 and broken up into single particles. The resulting deagglomerated particles 16 strike against the impact surface 56 of the impact element 54 and become further deagglomerated there.

[0096] FIG. 6 shows a top view of a separator wheel 60 with separator wheel paddles 62 and a corresponding air guidance system 70 with air guide vanes 73. The guide vane ring 72 of the air guidance system 70 has an inner diameter D.sub.L. The outer diameter of the separator wheel 60 is denoted as D.sub.S. This results in a width A.sub.4 of the annular separating space 18.

[0097] FIG. 7 shows a further embodiment of the air guidance system 70. The air guidance system 70 has two rings 79, between which an annular wall 71 with air windows 74 is arranged. The air windows 74 are arranged uniformly over the entire circumference of the annular wall 71. The embodiment shown here is a rectangular air window 74, having air guide vanes 73 in the form of guide plates 76 each time at the left edge 75. These guide plates 76 are able to swivel about an axis L.sub.SA, so that the angle of attack , which is drawn in FIG. 9, can be adjusted specifically.

[0098] In FIG. 9, the flow direction of the particle/air stream generated by the rotation of the separator wheel 60 in the direction of the arrow P.sub.1 is indicated by the arrow P.sub.2 in the separating space 18. The angle is subtended between the inner radius R.sub.L of the air guidance system 70 and the guide plate 76.

[0099] FIG. 8a shows the air guidance system 70 of FIG. 7 combined with a separator wheel 60. P.sub.1 indicates the rotation direction of the separator wheel 60. P.sub.2 denotes the flow direction of the particle/air stream.

[0100] FIG. 8b shows a further embodiment in which the guide plates 76 are curved in design. The guide plates 76 have a uniform radius of curvature R.sub.4 and are arranged curved in the direction of the separator wheel. The angle of attack is indicated by the tangent T through the center of the guide plate 76 and the inner radius of the air guidance system 70.

[0101] FIG. 8c shows a further embodiment in which the guide plates 76 do not have a uniform radius of curvature, but instead a radius of curvature which diminishes from outside to inside. The radius of curvature R.sub.6 at the end of the curved guide plate 76 is smaller than the radius of curvature R.sub.5.

[0102] FIG. 10 shows a further embodiment of the air guidance system 70, in which oppositely situated guide plates 77a, 77b are arranged respectively at both edges 75 of the air window 74. The incoming air stream is designed by the arrows drawn. While the guide plates 77a are short in configuration, the guide plates 77b are longer. In the embodiment shown here, the neighboring guide plates 77a and 77b of two windows 74 are respectively oriented parallel, so that an air duct of constant width is created. The ends 77c of the guide plates 77a, 77b do not touch and are spaced apart from each other.

[0103] FIG. 11 shows a further embodiment of the air guidance system 70, in which three guide vane rings 72 are arranged one above another, while between the rings 79 of neighboring guide vane rings 72 there is arranged a cone ring 80 each time. Furthermore, a horizontal annular air slot 78 is provided in this air guidance system 70, through which separating air is conveyed into the separating space 18.

[0104] FIG. 12 shows a cone ring 80 in cross section. The cone ring 80 has a particle guide element 82 with a first conical surface 84 on the upper face and a second conical surface 86 on the bottom side. The angle of inclination of the surface 84 to a vertical axis L.sub.V is designated by .

[0105] FIG. 13 shows the air guidance system 70 together with a separator wheel 60, so that it can be seen that the particle guide elements 82 protrude into the separating space 18. The distance A.sub.3 from the inner edge 88 of the particle guide elements 84 to the separator wheel is designated as A.sub.3. Furthermore, the diameters D.sub.L and D.sub.S as well as the distance A.sub.4 between the air guidance system 70 and the separator wheel 60.

[0106] Experiments have been carried out with a mineral powder as the feeding material. The particle sizes of the feeding material were <50 m, 70% of the particles having a size<10 m (d70=10 m). 20% of the particles had particle sizes<3 m.

[0107] This powder was classified in a traditional separator without the feed cone according to the invention and without the dispersing plate according to the invention. The corresponding cumulative distribution curve I is shown in FIG. 14, where the cumulative distribution Q.sub.3 (x) is plotted as a function of the grain size x, with Q.sub.3 (x)=(mass of the particlesparticle size x)/(total mass of all particles) (see Fine Grinding System with Impact Classifier Mill and Cyclone Classifier by Giersemehl and Plihal, Power Handling and Processing Vol. 11, No. 3, July/September 1999). The separating efficiency is =0.51.

[0108] The same powder was classified in a separator according to the invention with the feed cone, dispersing plate with dispersing blades and an impact ring according to the invention, per FIG. 1 to 5, and an air guidance system per FIG. 6.

[0109] The cumulative distribution curve II obtained with the separator according to the invention is likewise shown in FIG. 14. The curve II differs from the curve I by an improved separating efficiency with =0.56 and a boosted yield of particles with particle sizes<3 m. The yield for this particle range was 7.3% for the prior art (curve I) and 11.3% with the separator according to the invention (curve II). This is a higher yield by 54.8%.

[0110] It has been shown that the separator according to the invention results in a much better deagglomeration, as is manifested by the difference between the cumulative distribution curves I and II.

[0111] By using a separator according to the invention, which additionally has the air guidance system according to the invention per FIGS. 8 and 11, the separating efficiency for the same feeding material can be increased up to =0.7.

LIST OF REFERENCE NUMBERS

[0112] 1 Separator [0113] 2 Housing [0114] 3 Upper housing portion [0115] 4 Separator cover [0116] 5 Lower housing portion [0117] 6 Fill pipe [0118] 7 Fill opening for feeding material [0119] 8a,b Separating air feed [0120] 9 Outlet opening, fine material [0121] 10 Outlet opening, coarse material [0122] 11 Suction fan [0123] 12 Drive mechanism [0124] 13 Drive shaft [0125] 14 Feeding material [0126] 15 Agglomerate [0127] 16 Deagglomerated particles [0128] 18 Separating space [0129] 20 Feed cone [0130] 22 Fastening element [0131] 24 Cone edge [0132] 26 Cone apex [0133] 30 Dispersing plate [0134] 31 Upper face [0135] 32 Bottom side [0136] 33 Edge [0137] 34 Edge surface [0138] 40 Dispersing vane [0139] 41 Inner surface [0140] 42 Outer surface [0141] 43 Top surface [0142] 44 Inner circumference [0143] 46 Dispersing surface [0144] 50 Impact ring [0145] 52 Inner surface of impact ring [0146] 54 Impact element [0147] 56 Impact surface [0148] 58 Conical wall [0149] 60 Separator wheel [0150] 62 Separator wheel paddle [0151] 70 Air guidance system [0152] 71 Annular wall [0153] 72 Guide vane ring [0154] 73 Guide vanes [0155] 74 Air window [0156] 75 Edge of air window [0157] 76 Guide plate [0158] 77a,b Guide plate [0159] 77c Guide plate end [0160] 78 Air slot [0161] 79 Ring [0162] 80 Cone ring [0163] 82 Particle guide element [0164] 84 First conical surface [0165] 86 Second conical surface [0166] 88 Inner edge [0167] B.sub.P Width, impact element [0168] H.sub.P Height, impact element [0169] H.sub.S Height, dispersing vane [0170] L.sub.S Length, dispersing vane [0171] Cone angle of cone ring [0172] Aperture angle of feed cone [0173] Angle of attack of guide plate [0174] D.sub.L Inner diameter of air guidance system [0175] D.sub.S Outer diameter of separator wheel [0176] L.sub.SA Vertical swivel axis [0177] L.sub.V Vertical axis [0178] T Tangent [0179] R.sub.L Inner radius of air guidance system [0180] R.sub.1 Radius of cone edge [0181] R.sub.2 Radius of dispersing plate [0182] R.sub.3 Radius of inner circumference of dispersing blade [0183] R.sub.4 Radius of curvature [0184] R.sub.5 Radius of curvature [0185] R.sub.6 Radius of curvature [0186] A.sub.1 Distance feed cone edge to top surface of dispersing vane [0187] A.sub.2 Distance inner surface of impact element to edge surface of dispersing plate [0188] A.sub.3 Distance end of guide plate to outer circumference of separator wheel [0189] A.sub.4 Distance inner circumference of air guide ring to outer circumference of separator wheel [0190] P.sub.1 Rotation direction of separator wheel [0191] P.sub.2 Flow direction of particle air stream