Comminution plant
A comminution plant for comminuting material includes a set of fixed bottom knifes separated by parallel opening, two parallel shafts extending crosswise of the openings, a set of upper knifes attached on respective shafts and extending partly into the openings, and at least one drive assembly for rotating the shafts during operation. The upper knifes on one shaft include first and second knifes with the second one having a diameter which is smaller than the first. The upper knifes on the other shaft includes third and fourth knifes with the fourth one having a diameter which is smaller than the third. The diameters of the first and third knives are of a size which is larger than twice the distance between the axes of rotation of the at least two shafts. The comminution plant according to the invention can comminute a material effectively and to high degree of fineness.
1. A comminution plant for comminuting material and comprising at least one set of fixed bottom knifes separated by openings, at least two parallel shafts extending crosswise of the bottom knifes, a set of upper knifes attached on each shaft, with the upper knifes extending partly into the openings between the bottom knives, and at least one drive assembly for rotating the shafts during operation, wherein the upper knifes on one of the at least two shafts comprise at least one first upper knife having a first diameter and at least one second upper knife having a second diameter which is smaller than the first diameter, that the upper knifes on another of the at least two shafts comprise at least one third upper knife having a third diameter and at least one fourth upper knife having a fourth diameter which is smaller than the third diameter, and that the first diameter and third diameter together are of a size which is larger than twice the distance between the axes of rotation of the at least two shafts, wherein the sum of the sizes of the first diameter and the fourth diameter and of the second diameter and third diameter, respectively, is less than twice the distance between the axes of rotation of the at least two shafts.
2. The comminution plant according to claim 1 , wherein a first set of upper knifes with a first and fourth upper knife and a second set of upper knifes with a second and third upper knife are extending down into respective openings between two bottom knifes.
3. The comminution plant according to claim 2 , wherein the upper knifes do not overlap each other so that the openings can be minimized to facilitate the comminution of the material to a relatively high degree of fineness.
4. The comminution plant according to claim 1 , wherein the upper knifes in every set of upper knifes are in contact with or close to their respective bottom knife of the two bottom knifes defining an opening into which the respective set of upper knifes is extending.
5. The comminution plant according to claim 1 , wherein the width (b) of at least one opening between two bottom knifes is smaller than the total thickness (t) of a first and fourth upper knife and a second and third upper knife, respectively.
6. The comminution plant according to claim 1 , wherein the upper knifes are mainly disc-shaped and of the same thickness t and the openings are of the same width b wherein b<2t.
7. The comminution plant according to claim 1 , wherein the first and second sets of upper knifes alternately extend down into respective openings between two bottom knifes.
8. The comminution plant according to claim 1 , wherein the upper knifes in every set of upper knifes are displaced axially in relation to each other.
9. The comminution plant according to claim 1 , wherein the first diameter and third diameter are of the same size, and that the second diameter and fourth diameter are of the same size.
10. The comminution plant according to claim 1 , which partly comprises a centrally located set of bottom knifes separated by openings is into which the first or second sets of upper knifes are extending, and a peripheral set of bottom knifes separated by openings into which only one upper knife is extending.
11. The comminution plant according to claim 1 , wherein the upper knifes initially process or pass through the material more easily utilizing axial torsion moments while also extending the wear life of bottom knives.
12. A comminution plant for comminuting plate-shaped material and comprising at least one set of fixed bottom knifes separated by openings, at least two parallel shafts extending crosswise of the bottom knifes, a set of upper knifes attached on each shaft, with the upper knifes extending partly into the openings between the bottom knives, and at least one drive assembly for rotating the shafts during operation, wherein the upper knifes on one of the at least two shafts comprise at least one first upper knife having a first diameter and at least one second upper knife having a second diameter which is smaller than the first diameter, that the upper knifes on another of the at least two shafts comprise at least one third upper knife having a third diameter and at least one fourth upper knife having a fourth diameter which is smaller than the third diameter, and that the first diameter and third diameter together are of a size which is larger than twice the distance between the axes of rotation of the at least two shafts, wherein the sum of the sizes of the first diameter and the fourth diameter and of the second diameter and third diameter, respectively, is less than twice the distance between the axes of rotation of the at least two shafts, so that the upper knifes initially process or pass through the plate-shaped material more easily utilizing axial torsion moments while also extending the wear life of bottom knives; wherein a first set of upper knifes with a first and fourth upper knife and a second set of upper knifes with a second and third upper knife are extending down into respective openings between two bottom knifes and the upper knifes do not overlap each other so that the openings can be minimized to facilitate the comminution of the material to a relatively high degree of fineness.