CRUSHER ROTOR

Abstract

A rotor for a comminution apparatus that is arranged to launch material to be comminuted towards a surface, such as an anvil or an autogenous layer of crushed material. The rotor includes a frame including an upper plate, a lower plate and wall elements extending between the upper plate and the lower plate. The rotor further includes an inlet opening in the upper plate and an outlet located between the upper plate and the lower plate. An uppermost surface of the frame and a lowermost surface of the frame have a greater hardness than the rest of the frame such that additional wear protection elements may be omitted at those uppermost and lowermost surfaces.

Claims

1. Rotor for a comminution apparatus, said rotor being arranged to launch material to be comminuted towards a surface, said rotor comprising a frame including an upper plate, a lower plate and wall elements extending between said upper plate and said lower plate, the rotor further comprising an inlet opening in said upper plate and an outlet located between the upper plate and the lower plate, wherein the upper plate and the lower plate has a greater hardness than the wall elements such that an uppermost surface of the frame and a lowermost surface of the frame has a greater hardness than the rest of the frame such that additional wear protection elements can be omitted at those upper most and lowermost surfaces.

2. Rotor in accordance with claim 1, wherein the frame is provided in the form of a weldment.

3. Rotor in accordance with claim 1, wherein the frame is balanced about its intended rotational axis.

4. (canceled)

5. Rotor in accordance with claim 1, wherein a ratio of the hardness of at least one of the upper plate and the lower plate to the hardness of at least one of the wall elements lies in a range of 1.3 to 5.3.

6. Rotor in accordance with claim 1, wherein a ratio of the hardness of at least one of the upper plate and the lower plate to the hardness of at least one of the wall elements lies in a range of 2.5 to 3.

7. Rotor in accordance with claim 1, wherein a ratio of the tensile strength of at least one of the upper plate and the lower plate to the tensile strength of at least one of the wall elements lies in a range of 1.5 to 3.8.

8. Rotor in accordance with claim 1, wherein a ratio of the tensile strength of at least one of the upper plate and the lower plate to the tensile strength of at least one of the wall elements lies in a range of 2.2 to 2.6.

9. Rotor in accordance with claim 1, wherein the frame is configured to receive replaceable wear protection elements at exposed areas thereof.

10. Rotor in accordance with claim 9, wherein the replaceable wear protection elements are weight matched to reduce imbalance.

11. Rotor in accordance with claim 9, wherein the replaceable wear protection elements comprise one or more of the following: cavity wear plates; trail plates; rotor tips; distribution plate arranged at the lower plate, downstream from the inlet.

12. Rotor in accordance with claim 1, wherein a circumference of the upper plate and the lower plate have a generally circular shape.

13. Rotor in accordance with claim 12, wherein the upper plate and the lower plate have local recesses deviating from the circular shape.

14. Method for manufacturing a rotor for a comminution apparatus, said rotor being arranged launch material to be comminuted towards a surface, said method comprising the following steps providing rotor an upper plate having an inlet opening therein, a lower plate and wall elements; connecting said wall elements such that they extend between said upper plate and said lower plate and such that one or more outlets are created between the upper plate and the lower plate, wherein the upper plate and the lower plate has a greater hardness than the wall elements such that an uppermost surface of the upper plate and a lowermost surface of the lower plate has a greater hardness than the rest of the rotor such that additional wear protection elements may be omitted at those surfaces.

15. Comminution apparatus comprising a rotor in accordance with claim 1.

Description

BRIEF DESCRIPTIONS OF THE DRAWINGS

[0046] The invention will by way of example be described in more detail with reference to the appended drawings, which shows presently preferred embodiments of the invention.

[0047] FIG. 1 shows a perspective view of a comminution apparatus.

[0048] FIG. 2 shows an interior of the comminution apparatus of FIG. 1 comprising a rotor according to an embodiment of the present disclosure.

[0049] FIG. 3 shows a more detailed view of the rotor of FIG. 2.

[0050] FIG. 4 shows an interior of the rotor of FIGS. 2 and 3.

DETAILED DESCRIPTION

[0051] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled person.

[0052] FIG. 1 illustrates a comminution apparatus 100 for crushing or grinding rock, ore, cement clinker and other hard materials by way of example. The comminution apparatus 100 is configured to crush the materials by pushing them by force against metal but also by using the materials fed into the comminution apparatus 100 to crush itself. The comminution apparatus 100 may be a vertical shaft impact crusher. The crushing process of the comminution apparatus 100 will be discussed in further detail in connection with FIG. 2.

[0053] The comminution apparatus 100 comprises a roof 102 and a chamber 104. The chamber 104 is arranged on a base 106 of the comminution arrangement 100. The roof 102 is arranged on top of the chamber 104.

[0054] The comminution apparatus 100 further comprises a hopper 216 (see FIG. 2 for illustration). The hopper 216 is arranged inside the roof 102. The hopper 216 may comprise a centrally arranged opening in an upper part of the hopper 216. The hopper 216 may be configured to receive materials 216 to be crushed through the centrally arranged opening. The hopper 216 is further configured to feed the material 204 to the chamber 104.

[0055] The comminution arrangement 100 further comprises a rotor 108. The rotor 108 is arranged inside the chamber 102. The rotor 108 is configured to crush the material received in the chamber 102. Thus, the rotor is the main working component of the comminution apparatus 100. The rotor 108 will be further discussed in connection with FIGS. 2-4.

[0056] With reference to FIG. 2, the interior 200 of the comminution apparatus 100 is illustrated by way of example. Further to what have been discussed in connection with FIG. 1, the comminution apparatus 100 comprises a control gate 220. The control gate 220 may be arranged at a bottom end of the hopper 216. The control gate 220 is configured to alter cascade ratio. Thus, the control gate 220 is configured to control the amount of material 214 that is fed from the hopper 216 towards the rotor 108.

[0057] Further, the rotor 108 comprises a frame 202. The frame 202 includes an upper plate 204, a lower plate 206 and wall elements 208. The frame 202 is provided in the form of a weldment. The wall elements 208 extends between the upper plate 204 and the lower plate 206 and are perpendicular to the upper plate 204 and the lower plate 206. Put differently, the rotor 108 is manufactured by providing the rotor 108 with an upper plate 204, a lower plate 206 and wall elements 208. The wall elements 208 may be connected such that they may extend between the upper plate 204 and the lower plate 206. The rotor 108 further comprises an inlet opening 210 and an outlet 212. The inlet opening 210 is arranged in the upper plate 204. The outlet 212 is located between the upper plate 204 and the lower plate 206. The rotor 108 may comprise more than one outlet 212. The rotor 108 is illustrated in further detail in connection with FIGS. 3-4.

[0058] During operation of the comminution apparatus 100, the rotor 108 is configured to rotate. The rotor 108 is configured to rotate about a rotational axis A. The rotational axis is a vertical axis. Preferably, the rotor 108 rotates with 1800-3000 revolutions per minute (RPM) and a rotor tip speed may be up to 75 m/s. The maximum weight of the rotor 108 may be around 900-950 kg. Thus, with the heavy weight as well as the rather high speeds, the rotor 108 needs to be balanced in a correct way in order to perform the crushing process in the correct way. The rotor 108 is balanced at a factory, wherein the rotor 108 is produced. Forming the frame 202 of the weldment provides for that the rotor 108 only needs to be balanced at the factory and the consumer does not need to balance or turning the rotor 108 onsite. The rotor 108 may be balanced about its intended rotational axis A.

[0059] During operation, the materials 214 received by the rotor 108 are pushed away from the rotor 108 through the outlet 212 towards a surface 218. The surface 218 is arranged in the chamber 104. Put differently, the rotor 108 is configured to launch the material 202 to be comminuted towards the surface 218 within the chamber 104. The surface 218 may be an anvil. The surface 106 may comprise a build-up of material to be crushed, i.e. an autogenous layer of crushed material. The build-up in the comminution apparatus 100 is retained material, which forms the surface 218 over which feed material slides. It may form the shape of a wave with a crest towards the center of the rotor 108. The build-up may be arranged in the rotor 108 as well. The build-up in the rotor 108 is needed to protect the internal walls of the rotor 108 and most importantly, protect a rotor tip from direct wear and impact. The build-up may vary with material properties, rotor speed, feed rate, feed size and moisture content. This may provide for a crushing chamber creating an autogenous crushing. Such autogenous crushing has proven to guarantee superior shaped particles, for example aggregate. Preferably, the final product leaving the crusher 104 has a particle size of about 55 mm.

[0060] With reference to FIG. 3, the rotor 108 is illustrated in further detail by way of example. As discussed in connection with FIG. 2, the rotor 108 comprises the frame 202 provided in the form of the weldment. The frame 202 includes the upper plate 204, the lower plate 206 and the wall elements 208.

[0061] The upper plate 204 may have a circumference that has a generally circular shape. The lower plate 206 may have a circumference that may have a generally circular shape. As illustrated in FIG. 3, the upper plate 204 and the lower plate 206 may have local recesses 302. The local recesses 302 may deviate from the circular shape. With the arrangement, wherein the upper plate 204 and/or the lower plate 206 may have local recesses 302, provides for a reduce in weight of respective plate 204, 206 compared to conventional rotors. This may be advantageous as it improves the manufacturing as well as the maintenance operation of the rotor 108.

[0062] The upper plate 204 and the lower plate 206 may have a greater hardness than the wall elements 208. A ratio of the hardness of at least one of the upper plate 204 and the lower plate 206 to the hardness of at least one of the wall elements 208 may lie in a range of 1.3 to 5.3. The ratio of the hardness of at least one of the upper plate 204 and the lower plate 206 to the hardness of at least one of the wall elements 208 may lie in a range of 2.5 to 3. A ratio of the tensile strength of at least one of the upper plate 204 and the lower plate 206 to the tensile strength of at least one of the wall elements 208 may lie in a range of 1.5 to 3.8. The ratio of the tensile strength of at least one of the upper plate 204 and the lower plate 206 to the tensile strength of at least one of the wall elements 208 may lie in a range of 2.2 to 2.6.

[0063] The rotor 108 may further comprise an uppermost surface 304 of the frame 202 and a lowermost surface 306 of the frame 202. The uppermost surface 304 is arranged on the upper plate 204. The lowermost surface 306 is arranged on the lower plate 206. The uppermost surface 304 and the lowermost surface 306 has a greater hardness than the rest of the frame 202. An advantage achieved when the uppermost surface 304 and the lowermost surface 306 has greater hardness than the rest of the frame 202 is that additional wear protection elements may be omitted at those uppermost and lowermost surfaces 304, 306.

[0064] With reference to FIG. 4, an interior of the rotor 108 is illustrated by way of example. The frame 202 is further configured to receive replaceable wear protection elements at exposed areas thereof. The replaceable wear protection elements may be weight matched to reduce imbalance. Preferably, the replaceable wear protection elements are weight matched within 5-10 grams.

[0065] The replaceable wear protection elements may comprise cavity wear plates 202. The replaceable wear protection elements may comprise rotor tips 404.

[0066] The replaceable wear protection elements may comprise a distribution plate 206 arranged at the lower plate 206, downstream from the inlet 210 such that the one or more outlets 212 may be created between the upper plate 204 and the lower plate 206. The distribution plate 406 is arranged on an upper surface pf the lower plate 206. Preferably, the distribution plate 406 is a rotating distribution plate and as the material to be crushed hits the rotating distributor plate 406, the material will be hauled generally radially outwardly, through the outlets 212, and hit the surface 218 as discussed in connection with FIG. 2. The distribution plate 406 may be designed in different ways depending on the material to be crushed.

[0067] The replaceable wear protection elements may comprise lower wear plates 408.

[0068] The replaceable wear protection elements may comprise trail plates 410. The arrangement of the trail plate 410 may control the material build-up. Wide trail plates 410 make the material build-up deeper. Narrow tail plates 410 make the material build-up shallower. Moving the trail plates 410 away from the rotor tip 404 make the build-up shallower. Moving the trail plates 410 towards the rotor tip 404 make the material build-up deeper. The angle of the trail plate 410 may control the depth of build-up at the top and bottom of the rotor 108. An angled trail plate 410, a trail plate 410 with a wide base and a narrow top, may direct material more to the top of the rotor 108, raising the wear path on rotor tips 404 and reducing clearance around feed tube. Straight trail plate 410 may tend to direct material to the bottom of the rotor tip 404 and increase clearance around feed tube.

[0069] Thus, it is understood that the purpose of the disclosure is to reduce the problems with balancing of the rotor 108 and vibration of the rotor 108 while the comminution apparatus 100 is running. A further purpose is to reduce the machining needed during the manufacturing process and thereby also reduce the manufacturing challenges.

[0070] The person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.