Claims
- 1. An apparatus for classifying material by size comprising:
- a frame;
- a plurality of shafts mounted on the frame substantially parallel with one another;
- a first stage comprising discs, having S.sub.1 sides, mounted on the shafts in a substantially coplanar row, each of the discs having a perimeter shaped to maintain the space between discs substantially constant during rotation; and
- a second stage comprising discs, having S.sub.2 sides, mounted on the shafts in a substantially coplanar row, each of the discs having a perimeter shaped to maintain the space between discs substantially constant during rotation,
- wherein S.sub.1 and S.sub.2 are integers and S.sub.2 >S.sub.1, and the first stage discs are positioned to allow passage of only small faction material and the second stage discs are positioned to allow passage of intermediate fraction material thereby classifying the material into three fractions of particles having diameters of increasing size.
- 2. The apparatus of claim 1 wherein the perimeter of the first stage discs is defined by the steps comprising:
- (a) drawing a square, having four corners A, B, C, and D, the square having side length S defined as
- S=(L-D.sub.sp)* COS 45/COS 22.5,
- wherein L is the distance between two adjacent shafts and D.sub.sp is the distance between two adjacent coplanar discs; and
- (b) drawing arcs between corner A and corner B, corner B and corner C, corner C and corner D, and corner D and corner A, each arc having a radius R defined as
- R=L-D.sub.sp
- wherein L and D.sub.sp are defined as in step (a) above.
- 3. The apparatus of claim 1 wherein the apparatus further includes a plurality of first stage discs rows spaced apart from one another in substantially parallel relation and a plurality of second stage discs rows spaced apart from one another in a substantially parallel relation.
- 4. The apparatus of claim 1 wherein the shafts are rectangularly-shaped.
- 5. The apparatus of claim 1 wherein the discs of the first and second stages are generally flat and radiate outwardly from each of the shafts at right angles to the longitudinal axis of the shafts.
- 6. The apparatus of claim 1 wherein a plurality of either the first stage discs or the second stage discs are provided on each of the shafts, and further comprising means for selectively moving the plurality of discs mounted on each of the shafts toward or away from one another.
- 7. The apparatus of claim 1 further comprising a third stage of discs mounted on the shafts in a substantially coplanar row, each of the discs having a perimeter shaped to maintain the space between discs substantially constant during rotation, wherein the third stage discs are positioned to allow passage of large fraction material.
- 8. The apparatus of claim 1 wherein the small fraction material comprises particles having a diameter of less than about 4 inches and the intermediate fraction material comprises particles having a diameter of less than about 8 inches.
- 9. The apparatus of claim 7 wherein the small fraction material comprises particles having a diameter of less than about 2 inches, intermediate fraction material comprises particles having a diameter of less than about 4 inches, and large fraction material comprises particles having a diameter of less than 6 inches.
- 10. A method for classifying material by size using an apparatus, as defined by claim 1, which comprises:
- selectively moving the discs of one of the first and second stages to define a plurality of uniform openings disposed between the shafts;
- rotating the shafts in the same direction;
- dropping the material on the shafts at one side of the apparatus so that shaft rotation causes the material to be pushed by the discs across the remainder of the shafts in the apparatus; and
- maintaining the spacing between discs in a row substantially uniform during rotation.
- 11. An apparatus for classifying material by size comprising:
- a frame;
- a plurality of shafts mounted on the frame substantially parallel with one another;
- a first stage of discs mounted on the shafts in a substantially coplanar row, each of the discs having a perimeter shaped to maintain the space between discs substantially constant during rotation and defined by three arcs having substantially the same degree of curvature wherein the first stage discs are positioned to allow passage of particles having a diameter of less than about 2 inches; and
- a second stage of discs mounted on the shafts in a substantially coplanar row, each of the discs having a perimeter shaped to maintain the space between discs substantially constant during rotation and defined by four arcs having substantially the same degree of curvature wherein the second stage discs are positioned to allow passage of particles having a diameter of less than about 4 inches.
- 12. The apparatus of claim 11 further comprising a third stage of discs mounted on the shafts in a substantially coplanar row, each of the discs having a perimeter shaped to maintain the space between discs substantially constant during rotation and defined by five arcs having a substantially the same degree of curvature wherein the third stage discs are positioned to allow passage of particles having a diameter of less than about 6 inches.
- 13. A method for classifying material by size comprising the steps of:
- defining a first stage of substantially uniform openings disposed between a plurality of shafts arranged to define a substantially planar array, the first stage openings being sized to allow passage of small fraction material;
- defining a second stage of substantially uniform openings disposed between a plurality of shafts arranged to define a substantially planar array, the second stage openings being sized to allow passage of intermediate fraction material;
- mounting noncircular discs on the shafts in substantially parallel rows;
- rotating the shafts in the same direction such that (RPM).sub.1 =(S.sub.1 /S.sub.2) (RPM).sub.2, wherein (RPM).sub.1 is the revolutions per minute of the first stage discs, (RPM).sub.2 is the revolutions per minute of the second stage discs, S.sub.1 is the number of sides of the first stage discs, and S.sub.2 is the number of sides of the second stage discs, wherein S.sub.2 >S.sub.1 ;
- dropping the material on the shafts at one side of the array so that shaft rotation causes the material to be pushed by the discs across the remainder of the shafts in the array; and
- maintaining the spacing between discs in a row substantially uniform during rotation.
- 14. An apparatus for classifying material by size comprising:
- a frame;
- a plurality of shafts mounted on the frame substantially parallel with one another;
- a first stage comprising discs mounded on the shafts in a substantially coplanar row, each of the discs having a perimeter defined by three arcs having substantially the same degree of curvature; and
- a second stage comprising discs mounted on the shafts in a substantially coplanar row, each of the discs having a perimeter defined by four arcs having substantially the same degree of curvature,
- wherein the first stage discs are positioned to allow passage of only small fraction material and the second stage discs are positioned to allow passage of intermediate fraction material thereby classifying the material into three fractions of particles having diameters of increasing size.
- 15. The apparatus of claim 14 wherein the perimeter of the first stage discs is defined by the steps comprising:
- drawing an equilateral triangle having vertices A, B, and C;
- drawing an arc, having a center point located at vertex A, between end point B and vertex C; and
- drawing an arc, having a center point located at vertex B, between vertex C and vertex A.
- 16. The apparatus of claim 15 wherein the perimeter of the second stage discs is defined by the steps comprising:
- (a) drawing a square, having four corners A, B, C, and D, the square having side length S defined as
- S=(L-D.sub.sp)* COS 45/COS 22.5,
- wherein L is the distance between two adjacent shafts and D.sub.sp is the distance between two adjacent coplanar discs; and
- (b) drawing arcs between corner A and corner B, corner B and corner C, corner C and corner D, and corner D and corner A, each arc having a radius R defined as
- R=L-D.sub.sp
- wherein L and D.sub.sp are defined in step (a) above.
- 17. An apparatus for classifying material by size comprising:
- a frame;
- a plurality of shafts mounted on the frame substantially parallel with one another;
- a first stage comprising discs mounded on the shafts in a substantially coplanar row, each of the discs having a perimeter defined by four arcs having substantially the same degree of curvature; and
- a second stage comprising discs mounted on the shafts in a substantially coplanar row, each of the discs having a perimeter defined by five arcs having substantially the same degree of curvature,
- wherein the first stage discs are positioned to allow passage of only small fraction material and the second stage discs are positioned to allow passage of intermediate fraction material thereby classifying the material into three fractions of particles having diameters of increasing size.
- 18. An apparatus for classifying material by size comprising:
- a frame;
- a plurality of shafts mounted on the frame substantially parallel with one another;
- a first stage comprising discs mounted on the shafts in a substantially coplanar row, each of the discs having a perimeter defined by the steps comprising
- (a) drawing a square, having four corners A, B, C, and D, the square having side length S defined as
- S=(L-D.sub.sp)* COS 45/COS 22.5,
- wherein L is the distance between two adjacent shafts and D.sub.sp is the distance between two adjacent coplanar discs, and
- (b) drawing arcs between corner A and corner B, corner B and corner C, corner C and corner D, and corner D and corner A, each arc having a radius R defined as
- R=L-D.sub.sp
- wherein L and D.sub.sp are defined as in step (a) above;
- a second stage comprising discs mounted on the shafts in a substantially coplanar row, each of the discs having a perimeter defined by the steps comprising
- drawing a regular pentagon having vertices A, B, C, C, and E,
- drawing an arc, having a center point located at vertex D, between vertex A and vertex B,
- drawing an arc, having a center point located at vertex E, between vertex B and vertex C,
- drawing an arc, having a center point located at vertex A, between vertex C and vertex D,
- drawing an arc, having a center point located at vertex B, between vertex D and vertex E, and
- drawing an arc, having a center point located at vertex C, between vertex E and vertex A,
- wherein the first stage discs are positioned to allow passage of only small fraction material and the second stage discs are positioned to allow passage of intermediate fraction material thereby classifying the material into three fractions of particles having diameters of increasing size.
Parent Case Info
This is a continuation in part of application Ser. No. 08/112,411, filed Aug. 26, 1993, abandoned.
US Referenced Citations (18)
Foreign Referenced Citations (2)
Number |
Date |
Country |
592126 |
Jan 1934 |
DEX |
609919 |
Feb 1935 |
DEX |
Non-Patent Literature Citations (1)
Entry |
Bulk Handing Systems Product Brochure, BHS Disc-Screens, two pages. |
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
112411 |
Aug 1993 |
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