WO2012131162A1

WO2012131162A1 - Crusher

Info

Publication number: WO2012131162A1
Application number: PCT/FI2012/050294
Authority: WO
Inventors: Jarkko Nurmi
Original assignee: Bmh Technology Oy
Priority date: 2011-03-25
Filing date: 2012-03-23
Publication date: 2012-10-04
Also published as: FI20115288L; AT14416U1; FI20115288A0; CN203470076U; DE212012000029U1; FI10270U1

Abstract

The invention relates to a crusher comprising two adjacent crusher rotors (4, 5) with crusher teeth (6, 7) on their circumferences, counterblade structures (8, 9) locating on side walls (3) of the crusher frame (1) and cooperating with said crusher teeth, and screen sets (10, 11) beneath each crusher rotor so as to screen the material crushed to a given particle size out of the crusher. The first crusher rotor (4) is for coarse crushing and the second crusher rotor (5) is for fine crushing, and consequently they are provided with crusher teeth (6, 7) of different sizes, and correspondingly, different counter- blade structures (8, 9) are provided with counterblades of different sizes, mesh sizes in the screen sets (10, 11) beneath each crusher rotor being selected with the intention to produce a product in accordance with the requirement set for the final particle size.

Description

Crusher

Background of the invention

[0001] The invention relates to a crusher comprising a box-like crusher frame, which includes two end walls and two side walls connecting the end walls; two adjacent crusher rotors, which are supported for rotary motion inside the crusher frame on the end walls thereof; whereby the circumferences of both crusher rotors comprise a plurality of crusher teeth, and the side walls of the crusher frame comprise counterblade structures cooperating with the crusher teeth of both crusher rotors, and material to be fed into the crusher is arranged for being crushed between the crusher teeth of the crusher rotors and the counterblade structures as the crusher rotors are rotated; a feed point for the material to be crushed in the upper part of the crusher frame; and screen sets underneath each crusher rotor, at a selected distance from the crusher rotor teeth and arranged to extend to a selected angular area of each crusher rotor for screening the material crushed to a given particle size out of the crusher.

[0002] There are known two-rotor crushers with identical crusher rotors in the same crusher. In that case the rotors may be mirror images of one another, rotate at the same speed and operate independently at the same time (in the same direction, in different directions, change the direction, etc.).

[0003] Typically, the material to be crushed, i.e feed material, which has large dimensions or large particle size, is crushed in a slow speed tearing crusher. This crusher equipped with coarse-teeth crusher rotors does not provide sufficiently small particle size in the end product, even though gripping in the feed material and the capacity are good.

[0004] Whereas, if a crusher equipped with fine-teeth crusher rotors is employed for crushing, in most cases, the rotors grip poorly the feed material, which is often large in dimensions, such as wood or tree stumps. In addition, finer cogging is weaker when considering impurities, such as stones and the like, often accompanying the feed material. Fines, such as sand, also wear the cogging unnecessarily, which fines are screened in a coarse-teeth crusher at the very early stages.

[0005] To compensate for poor gripping it is often necessary to load an extra amount of feed material on the rotors to serve as weight. This causes extra wear in the rotors as well as power consumption. In addition, the stalling of the crusher induced by impurities, if any, results in a cumbersome cleaning operation of a crusher jaw.

Summary of the invention

[0006] The object of the invention is to develop the crusher of the above-described type in such a manner that the aforementioned problems will be solved. This is achieved by a crusher according to the invention, which is characterized in that one crusher rotor is for coarse crushing and another crusher rotor is for fine crushing, and the different crusher rotors are provided with crusher teeth of different sizes, and correspondingly, different counter- blade structures are provided with counterblades of different sizes, and that mesh sizes of screen sets beneath the crusher rotors are selected with the intention to produce a product in accordance with the requirement set for final particle size. The preferred embodiments of the invention are disclosed in the dependent claims.

[0007] The invention is thus based on a combination of a coarse crusher and a fine crusher. The crushing of feed material is performed against counterblade structures locating on the side walls of the crusher frame, the rotors rotating towards the side walls. The rotors are rotated towards the centre only to break up emerging material arches, if any, or to remove overload. The particle size of the end product is determined by the screen sets beneath the rotors.

[0008] The material to be crushed is fed on the side of the rotor having coarser cogging. Oversized material, which has not passed through the screen set beneath this particular rotor, rises from the middle of the rotors upwards and will be subjected to a similar crushing treatment with the rotor having finer cogging.

List of figures

[0009] The invention will be described now in greater detail by means of one preferred embodiment with reference to the attached drawing, which is a simplified cross-sectional view of a crusher of the invention.

Detailed description of the invention

[0010] With reference to the drawing, there is shown a crusher of the invention, by way of example and in a highly simplified manner, the crusher including a box-like frame 1 with two end walls 2 (of which only the rearmost is visible) and two side walls 3 connecting the end walls 2. Inside the crusher frame 1 , on its end walls 2 there are supported two adjacent crusher rotors 4 and 5, which are operated, i.e. rotated with conventional actuators, not shown. On the circumferences of both crusher rotors 4 and 5 there are a plurality of crusher teeth 6 and 7, and on the side walls 3 of the crusher frame 1 there are counterblade structures 8 and 9 cooperating with the respective crusher teeth 6 and 7 of each crusher rotor 4 and 5. The material to be fed into the crusher, i.e. feed material F is intended for being crushed between the crusher teeth 6 and 7 of the crusher rotors 4 and 5 and the counterblade structures 8 and 9 while the crusher rotors 4 and 5 are rotated in the direction of the arrows shown in the drawing. The feed point 12 of the feed material F to be crushed is located in the upper part of the crusher frame 1 . In addition, there are screen sets 10 and 1 1 underneath each crusher rotor 4 and 5, at a selected distance from the teeth 6 and 7 of the crusher rotors 4 and 5, and they are arranged to extend to a selected angular area of each crusher rotor 4 and 5 for screening the material crushed to a given particle size out of the crusher.

[0011] What is particular in this crusher is that a first crusher rotor 4 is for coarse crushing and a second crusher rotor 5 is for fine crushing, and consequently these crusher rotors 4 and 5 are provided with crusher teeth 6 and 7 of different sizes, and correspondingly, different counterblade structures 8 and 9 are provided with counterblades of different sizes which are suitable for cooperation with the above-mentioned crusher teeth 6 and 7; and that mesh sizes in the screen sets 10 and 1 1 beneath each crusher rotor 4 and 5 are selected with the intention to produce a product in accordance with the requirement set for the final particle size. Naturally, the feed point 12 of the material to be crushed, i.e. the feed F, is thus located at and above the crusher rotor 4 for coarse crushing.

[0012] As already stated above, the crushing of the feed material F is performed against the counterblade structures 8 and 9, the rotors 4 and 5 rotating towards the side walls 3. The rotors 4 and 5 are rotated towards the centre only to break up emerging material arches, if any, or to remove overload. The particle size in the end product is determined by the screen sets 10 and 1 1 . Oversized material, which has not passed through the screen set 10 beneath the rotor 4, rises from the middle of the rotors 4 and 5 upwards and will be subjected to a similar crushing treatment with the rotor 5 having finer cogging. [0013] Preferably, the screen sets 10 and 1 1 extend from below the counterblade structures 8 and 9 to the area between the rotors 4 and 5, approximately to the height of the axles of the rotors 4 and 5, and they are connected to a shaped central beam 13 running between the rotors 4 and 5 and supported to the end walls 2 of the crusher frame 1 .

[0014] Each crusher rotor 4 and 5 may be arranged to operate independently, their diameters may be substantially equal in size, or if so desired, different in size. Correspondingly, their rotating speeds may be either equal or different. Likewise, the mutual axle level of the crusher rotors 4 and 5 may be modified. All the above parameters are selected according to each particular feed material F and the desired end product thereof as well as according to the situation in question.

[0015] The above description of the invention is only intended to illustrate the basic idea of the invention. A person skilled in the art may thus vary its details within the scope of the accompanying claims.

Claims

1 . A crusher comprising:

a box-like crusher frame (1 ), which includes two end walls (2) and two side walls (3) connecting the end walls;

two adjacent crusher rotors (4, 5), which are supported for rotary motion inside the crusher frame (1 ) on the end walls (2) thereof; whereby the circumferences of both crusher rotors (4, 5) comprise a plurality of crusher teeth (6, 7), and the side walls (3) of the crusher frame (1 ) comprise counter- blade structures (8, 9) cooperating with the respective crusher teeth (6, 7) of both crusher rotors (4, 5), and material (F) to be fed into the crusher is arranged for being crushed between the crusher teeth (6, 7) of the crusher rotors (4, 5) and the counterblade structures (8, 9) as the crusher rotors (4, 5) are rotated;

a feed point (12) for the material to be crushed in the upper part of the crusher frame (1 ); and

screen sets (10, 1 1 ) underneath each crusher rotor (4, 5), at a selected distance from the teeth (6, 7) of the crusher rotors (4, 5) and arranged to extend to a selected angular area of each crusher rotor (4, 5) for screening the material crushed to a given particle size out of the crusher;

c h a r a c t e r i z e d in that one crusher rotor (4) is for coarse crushing and another crusher rotor (5) is for fine crushing, and the different crusher rotors (4, 5) are provided with crusher teeth (6, 7) of different sizes, and correspondingly, different counterblade structures (8, 9) are provided with counterblades of different sizes, and that mesh sizes in screen sets (10, 1 1 ) beneath the crusher rotors (4, 5) are selected with the intention to produce a product in accordance with the requirement set for final particle size.

2. The crusher of claim 1 , c h a ra ct e r i z e d in that the feed point (12) of the material to be crushed is located at and above the crusher rotor (4) for coarse crushing.

3. The crusher of claim 1 or 2, c h a r a c t e r i z e d in that the screen sets (10, 1 1 ) extend from below the counterblade structures (8, 9) to an area between the rotors (4, 5), approximately at the height of the axles of the rotors (4, 5), and they are connected to a shaped central beam (13) running between the rotors (4, 5) and supported to the end walls (2) of the crusher frame (1 ).

4. The crusher of any one of the preceding claims, c h a ra ct e ri z e d in that both crusher rotors (4, 5) are arranged to operate independently.

5. The crusher of any one of the preceding claims, characterized in that the diameters of the crusher rotors (4, 5) are substantially equal in size.

6. The crusher of any one of claims 1 to 4, characterized in that the diameters of the crusher rotors (4, 5) are different in size.

7. The crusher of any one of the preceding claims, characterized in that the rotating speeds of the crusher rotors (4, 5) are substantially equal.

8. The crusher of any one of claims 1 to 6, characterized in that the rotating speeds of the crusher rotors (4, 5) are different.

9. The crusher of any one of the preceding claims, characterized in that the axles of the crusher rotors (4, 5) are located substantially on the same level.

10. The crusher of any one of the preceding claims, characterized in that the axles of the crusher rotors (4, 5) are located on different levels.