Granules conditioner

Abstract

The present invention concerns a granular material conditioner for optimising grain sizes of granular materials comprising two discs which are rotatable relative to each other and which are arranged in substantially mutually parallel relationship, a granular material inlet through which granular material can be passed into the conditioner into an annular gap between the two discs, and a catch container for receiving the granular material which issues from the gap between the two discs by virtue of centrifugal force. According to the invention it is proposed that the catch container has an elastic curtain, wherein the curtain is spaced at least portion-wise from the catch container wall and limits the trajectory of the granular material issuing from the gap.

Claims

1. A granular material conditioner for granular materials comprising two discs which are rotatable relative to each other and which are arranged in parallel, a granular material inlet through which granular material passes into the conditioner into an annular gap between the two discs, and a catch container for receiving the granular material which issues from the gap between the two discs by virtue of centrifugal force, characterised in that the catch container has a wall and an elastic curtain, wherein at least a portion of the curtain is spaced from the catch container wall and limits the trajectory of the granular material issuing from the gap, the elastic curtain including an angle of between 15 and 75 with a notional radial prolongation of the annular gap, the elastic curtain having an S-shaped cross-section, and a concave portion closer to the gap and a convex portion adjoining the concave portion, wherein the notional radial prolongation of the annular gap intersects the elastic curtain in the proximity of the connection between the concave portion and the convex portion.

2. A granular material conditioner according to claim 1 characterised in that the elastic curtain is arranged completely surrounding the pair of discs.

3. A granular material conditioner according to claim 2 characterised in that the elastic curtain is of a bell-shaped configuration.

4. A granular material conditioner according to claim 1 characterised in that the elastic curtain is substantially flat at the side towards the gap, without knobs, grooves or ribs.

5. A granular material conditioner according to claim 1 characterised in that both discs are rotatable about their disc axis.

6. A granular material conditioner according to claim 1 characterised in that one of the two discs has a central opening, by way of which the granular material can be fed into the annular gap.

7. A granular material conditioner according to claim 6 characterised in that the disc which has the central opening is drivable with a hollow shaft, through which the granular material is fed into the gap by way of the central opening.

8. A granular material conditioner according to claim 1 characterised in that the two discs are oriented horizontally perpendicular to the vertical direction.

9. A granular material conditioner according to claim 8 wherein there is provided a pivoting device, by means of which one disc of the two discs, is pivotable about a pivot axis which extends parallel to the plane of the gap.

10. A granular material conditioner according to claim 9, wherein the pivotable disc is the upper disc.

11. A granular material conditioner according to claim 1 characterised in that the annular gap has one or more portions which are conical in cross-section.

12. A granular material conditioner according to claim 1 characterised in that at least one disc of the two discs is driven at a peripheral speed of more than 10 m/s.

13. A granular material conditioner according to claim 12 wherein when both discs are driven the peripheral speeds of the two discs are different.

14. A granular material conditioner according to claim 13 the peripheral speed of the one disc is at least 10% greater than the peripheral speed of the other disc.

15. A granular material conditioner according to claim 1 characterised in that the discs are substantially flat at their surfaces forming the gap.

Description

(1) Further advantages, features and possible uses of the present invention will be apparent from the following description of a preferred embodiment and the accompanying Figures in which:

(2) FIG. 1 is a diagrammatic view of the operating principle of the granular material conditioner or conditioning device 100.

(3) FIG. 2 shows a sectional view through a part of a conditioner 100 according to the invention.

(4) FIG. 4 is an enlarged view of a portion of the conditioner shown in FIG. 2.

(5) FIG. 1 diagrammatically shows the operating principle of the conditioner according to the invention. The conditioner has two rotating discs 1, 2 which are driven in such a way that they rotate relative to each other. In the illustrated example the two discs are driven in different directions. An annular gap 7 remains between the two discs. The upper disc 2 is driven by means of a hollow shaft or granular material inlet 4 through which granular material to be optimised can be fed. The lower disc 1 has at the centre a central cone 5 and a row of vanes 6. The granular material which is passed by way of the hollow shaft 4 between the discs under the effect of the force of gravity is moved radially outwardly by the cone 5 and the vanes 6 so that it is transported into the annular gap 7 by virtue of the radial acceleration. In the gap the granular material is comminuted until it issues again from the annular gap 7 at the periphery thereof.

(6) It will be seen that the annular gap 7 has a conically converging portion which is arranged radially further inwardly and a portion in which the gap remains substantially constant and which adjoins the conically converging portion so that it is arranged radially further outwardly.

(7) The granular material is comminuted in the conically converging portion so that the granular material can be subsequently rolled in the radially outwardly adjoining gap portion of a substantially constant gap width. As an alternative thereto it would also be possible to provide a plurality of conically converging portions.

(8) The discs shown in FIG. 1 are usually mounted in a catch container.

(9) FIG. 2 shows an embodiment of the invention. The conditioner is shown here as a sectional view. As far as possible the same references are used as those in FIG. 1. Here too the granular material can be supplied by way of the hollow shaft 4. The lower disc 1 is driven by way of the shaft 8 while the upper disc 2 is driven by way of the hollow shaft 4. The granular material is comminuted in the annular gap 7 and radially accelerated by the rotating discs so that it issues from the annular gap 7 at the periphery at a not inconsiderable speed. In the known conditioners the issuing granular material impacts against the housing wall which closely surrounds the ejection gap and is conveyed from there in the direction of the granular material discharge for example by means of rotating clearing-out fingers.

(10) Particularly when the granular material is of average moisture content it can however happen that the granular material issuing from the annular gap 7 at high speed adheres to the housing wall so that accumulations of granular material form there, which can then uncontrolledly detach from the wall. The pieces which become detached comprise small grains of granular material which adhere to each other and which cannot be used for further processing.

(11) Therefore the conditioner according to the invention has an elastic curtain 11 so arranged that the granular material grains issuing from the annular gap 7 firstly hit the elastic curtain 11. The elastic curtain 11 which is of a bell-shaped configuration in the preferred embodiment is arranged spaced relative to the wall of the catch container 10 so that, upon impact of granular materials, it is caused to oscillate, which provides that the probability of granular material remaining clinging to the elastic curtain is markedly reduced. Nonetheless the possibility of individual grains of granular material adhering to the curtain can also not be excluded here. Therefore the curtain is so arranged that the grains issuing from the annular gap meet the elastic curtain 11 substantially at an impact angle of about 40 to 50 degrees. That has the advantage that a grain of granular material which is already adhering to the elastic curtain 11 is not pressed against the elastic curtain by the impact of a further grain, but is displaced thereon by the impact thereon of the following particle, which generally has the effect that the grain adhering to the curtain is detached and dropped into the catch container 9.

(12) In the particularly preferred embodiment the elastic curtain is of a substantially S-shaped configuration in cross-section, that is to say it has a concave region and an adjoining convex region, wherein the concave region is arranged closer to the annular gap 7. In that respect the curtain 11 is so arranged that the granular material issuing from the gap meets the curtain substantially in the proximity of the connection between the concave region and the convex region.

(13) As can be seen in FIG. 4, the notional radial prolongation 50 of the annular gap 7 intersects the elastic curtain 11 at an angle 52, and the elastic curtain 11 has an S-shaped cross-section with a concave downward portion 54 and a convex downward portion 56, which meet at the intersection of the notional radial prolongation 50 and the elastic curtain 11.

(14) To be able to adjust the size of the granular material by altering the width of the annular gap 7 one of the rotating discs 1 or 2 is mounted adjustably in height. Height adjustment of the gap 12 can be effected by way of a mounting point or by way of a plurality of and preferably three mounting points so that, besides the gap width, it is also possible to adjust 15 the parallelism of the discs relative to each other by individual adjustment of the mounting points, the plurality of mounting points thus comprising a pivoting device 24.

(15) The peripheral speed of at least one disc should be more than 10 m/s and preferably more than 20 m/s. When the discs are driven the one disc should involve a peripheral speed which is at least 10% greater than the peripheral speed of the other disc.

(16) The present invention also provides apparatus 110 for the production of an optirinised granular material comprising a housing 26 in which there are arranged a granulating mixer 28 for producing a granular material from powders and possibly liquid and a granular material conditioner 100, as shown schematically in FIG. 3.

LIST OF REFERENCES

(17) 1 lower disc 2 upper disc 3 granular material 4 hollow shaft 5 cone 6 vanes 7 annular gap 8 shaft 9 catch container 10 catch container wall 11 curtain 12 gap height adjustment