阅读说明：本技术 在高速粉碎磨机中使用的冲击工具 (Impact tool for use in high speed pulverizer ) 是由 彼得·罗伯特·布什 乔妮·克里斯汀·帕雷德斯·尊尼加 贝恩德·海恩里希·里斯 哈比卜·萨里迪克 于 2018-12-20 设计创作，主要内容包括：本公开涉及一种在高速、高撞击能粉碎磨机中使用的冲击工具。所述冲击工具包括可在第一端附接至粉碎磨机的细长主体,并进一步包括用于改善冲击工具耐磨性的耐磨件,该耐磨件包括多个独立单元。(The present disclosure relates to an impact tool for use in a high speed, high impact energy pulverizing mill. The impact tool comprises an elongated body attachable to a pulverizer mill at a first end, and further comprises a wear part for improving wear resistance of the impact tool, the wear part comprising a plurality of individual cells.)

1. An impact tool for use in a high speed, high impact energy pulverizing mill, said impact tool comprising an elongated body attachable at a first end to said pulverizing mill, and further comprising a wear part for improving wear resistance of the impact tool, said wear part comprising a plurality of independent units.

2. The impact tool of claim 1, wherein the wear member extends from a second end opposite the first end toward the first end to at most 90% of a longitudinal length of the impact tool.

3. The impact tool of claim 1, wherein the wear member is disposed to surround a leading edge of the impact tool.

4. The impact tool of claim 3, wherein the wear member comprises a series of wear resistant teeth arranged side-by-side.

5. The impact tool of claim 1, wherein the wear member is disposed on or within a first surface of the impact tool.

6. The impact tool of claim 5, wherein the wear member is disposed on or within first and second adjacent surfaces of the impact tool.

7. An impact tool, as claimed in claim 5 or 6, in which the wear member comprises a plurality of projections extending outwardly from the or each surface of the impact tool.

8. An impact tool according to claim 7, wherein the projection is an insert provided in a correspondingly shaped recess in the or each surface.

9. An impact tool, as claimed in claim 8, wherein said insert has a rounded profile at or above the or each surface of the impact tool.

10. An impact tool according to claim 7, 8 or 9, wherein the projections are arranged in an ordered array on the or each surface.

11. The impact tool of claim 7, 8 or 9, wherein the protrusion is configured to be more compact closer to the second end.

12. An impact tool, as claimed in any one of the preceding claims, further comprising an elongate rib extending outwardly from a surface of the impact tool.

13. An impact tool, as claimed in claim 5 or 6, wherein the wear part comprises a series of plates arranged in a side-by-side configuration and attached to the or each surface of the impact tool.

14. A percussion tool according to any one of the preceding claims, wherein the wear part comprises polycrystalline diamond (PCD) material.

15. The impact tool of any of claims 1 to 14, wherein the wear part comprises a cemented carbide material.

16. An impact tool for use in a high speed pulverizer, the impact tool comprising an elongated body attachable at a first end to the high speed pulverizer, and further comprising a wear member for improving wear resistance of the impact tool, the wear member comprising a wear layer extending over portions of the body to form a hardened surface.

17. The impact tool of claim 16, wherein the wear layer has a predetermined variable layer thickness covering two or more different areas of the body.

18. The impact tool of claim 16 or 17, wherein the wear part comprises polycrystalline diamond (PCD) material.

19. The impact tool of claim 16 or 17, wherein the wear part comprises one or more cemented carbide materials.

Technical Field

The present disclosure relates to an impact tool for use in a high speed, high impact energy pulverizing mill. Such mills are commonly used to break rock and minerals extracted from mines.

Background

Similar to high pressure roller mills (HPGR), pulverisation mills are one of the many ways to break rock and minerals. The rock formation enters the mill through the inlet and exits the mill through the outlet. As the rock formations pass through the mill, rotors and/or stators that operate to reduce the effective diameter of these formations are encountered. Many mills have tines designed to impact and break down falling rock, reducing particle size from one size fraction to another. The blades of the rotor are subjected to severe wear and produce defects such as edge chips due to the large forces.

For example, EP2851122B1 discloses a comminution apparatus for mechanically comminuting polymers of materials composed of materials of different densities and/or consistencies. The apparatus comprises a cylindrical crushing chamber containing vertically stacked rotatable impact tools. The feed inlet is positioned at the upper part of the crushing chamber, and the discharge outlet is positioned at the bottom of the crushing chamber. The polymer passes through the crushing chamber, mainly under the influence of gravity, travels from the inlet opening to the outlet opening and hits the impact tool on the way.

When each impact tool is severely worn and/or severely flawed, catastrophic failure often results, further damaging other impact tools within the mill. The mill operation must be stopped and each damaged impact tool replaced.

Disclosure of Invention

It is an object of the present invention to provide an impact tool for use in a pulverizer mill having improved wear and fracture resistance, thereby extending the operating life and operating efficiency of the mill.

One aspect of the present invention provides an impact tool for use in a high speed, high impact energy pulverizing mill, the impact tool comprising an elongated body attachable at a first end to the pulverizing mill, and further comprising a wear part for improving wear resistance of the impact tool, the wear part comprising a plurality of individual cells.

The wear part may extend from a second end opposite the first end towards the first end up to 90% of the longitudinal length of the impact tool.

The wear member may be arranged to surround a leading edge of the impact tool.

The wear member may comprise a series of wear resistant teeth arranged side by side.

The wear part may be provided on or in the first surface of the impact tool.

The wear part may be provided on or in the first and second adjacent surfaces of the impact tool.

Optionally, the wear part comprises a plurality of projections extending outwardly from the or each surface of the impact tool.

Optionally, the projection is an insert provided in a correspondingly shaped recess in the or each surface.

Preferably, the insert has a rounded profile at or above the or each surface of the impact tool.

The protrusions are arranged in an ordered array on the or each surface.

The closer the protrusion may be disposed to the second end, the more compact the assembly (packed) may be.

Optionally, the impact tool further comprises an elongate rib extending outwardly from a surface of the impact tool.

The wear part may comprise a series of plates arranged in a side-by-side configuration and attached to the or each surface of the impact tool.

Optionally, the wear part comprises polycrystalline diamond (PCD) material.

Preferably, the wear part comprises a cemented carbide material.

Another aspect of the invention provides an impact tool for use in a high speed pulverizing mill, the impact tool comprising an elongated body attachable at a first end to the high speed pulverizing mill, and further comprising a wear member for improving wear resistance of the impact tool, the wear member comprising a wear layer extending over a portion of the body to form a hardened surface.

The wear layer may have a predetermined variable layer thickness covering two or more different regions of the body.

Optionally, the wear part comprises polycrystalline diamond (PCD) material.

Preferably, the wear part comprises one or more cemented carbide materials.

Drawings

The invention will now be described in detail, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 shows a perspective view of a prior art rotor shaft and impact tool;

fig. 2 shows a perspective view of the impact tool of the first embodiment;

FIG. 3 shows a perspective view of an impact tool of a second embodiment;

FIG. 4 shows a perspective view of an impact tool of a third embodiment;

FIG. 5 is a perspective view showing an impact tool of a fourth embodiment;

FIG. 6 shows a perspective view of an impact tool of a fifth embodiment;

FIG. 7 is a perspective view showing an impact tool of a sixth embodiment;

fig. 8 shows a perspective view of an impact tool of a seventh embodiment;

fig. 9 shows a perspective view of an impact tool of an eighth embodiment;

fig. 10 shows an exploded perspective view of an impact tool of an eighth embodiment; and

fig. 11 shows a perspective view of an impact tool of a ninth embodiment.

Detailed Description

Fig. 1 shows a prior art rotor shaft 10 and a plurality of impact tools 12 as disclosed in EP2581122B 1. The impact tools 12 are mounted about the rotor shaft 10 such that they are rotatable about an axis of rotation extending through the rotor shaft 10. The rotor speed is typically 800-. The rotor shaft 10 is housed within a cylindrical pulverizing chamber (not shown) of a high-speed pulverizing mill. Attrition mills are commonly used to separate precious metal particles and mineral compounds from hot slag and ore. Exemplary starting materials to be degraded or depolymerized are basalt having a length of about 300 mm and iron ore having a length of about 150 mm.

The crushing chamber is provided with a feeding hole and a discharging hole. The rotor shaft 10 is arranged vertically and the material formation or polymer to be degraded or separated enters the top of the crushing chamber through the feed opening. A plurality of sections 14a, 14b and 14c are axially disposed along the length of the rotor shaft 10. Each section 14a, 14b and 14c contains a plurality of impact tools 12 for crushing the material entering the crushing chamber. The impact speed can reach more than 200 meters per second. The present invention relates only to the impact tool 12.

Referring now to fig. 2, an impact tool in accordance with a first embodiment of the present invention is generally referred to herein by the reference numeral 16. The impact tool 16 comprises an elongated body attachable at a first end 20 to the high speed, high impact energy pulverizer rotor shaft 10, and further comprises a wear member comprising a plurality of individual cells.

The manner in which the body 18 is attached or connected to the pulverizer is not relevant to the present invention, so any connection, engagement or attachment between the two is suitable for use in the present invention.

The configuration of the impact tool 16 is directional in that it is not axially symmetrical in the radial direction with respect to the rotor shaft 10. The impact tool 16 comprises a leading side 22 and a trailing side 24, said leading side 22 and trailing side 24 being defined relative to a desired direction of rotation about the rotor shaft 10 in use.

In the present embodiment, the impact tool 16 is a rectangular parallelepiped, and its transverse cross section is generally rectangular. However, other shapes or forms of cross-section are also contemplated, for example, the impact tool 16 may be generally cylindrical and thus circular in transverse cross-section. Alternatively, the impact tool 16 may be a triangular prism having a triangular transverse cross section. Alternatively, the impact tool 16 may be a pentagonal prism having a pentagonal transverse cross section. Alternatively, the impact tool 16 may be a hexagonal prism having a hexagonal transverse cross section. Irregular geometric three-dimensional shapes are also possible. Obviously, the surface may be planar or arcuate.

The body 18 of the impact tool 16 includes a base 25, which base 25 is steel in this embodiment. The steel may be surface hardened. Non-steel materials may be used instead of, or in addition to, steel. Ferrous or non-ferrous metals may be used. For example, the body 18 may comprise diamond impregnated in a metal matrix.

The body 18 may be unitary or may alternatively comprise a protective layer or hard shell covering a core made of another material. Preferably, the material used as the first material of the core has a greater fracture toughness than the second material of the outer layer (i.e. the protective layer), while the second material has a higher hardness and wear resistance than the first material. However, since the impact tool 16 comprises a wear part, the opposite is also possible, although not preferred, namely: the second material has a higher fracture toughness than the first material, and the first material has a higher wear resistance than the second material.

The impact tool body 18 comprises two joined body portions, of which a first body portion 18a is substantially conical (with a rounded apex) in plan view and a second body portion 18b is rectangular in plan view. The second body portion 18b is circumferentially (i.e., laterally) narrower than the first body portion 18a such that there is a single shoulder 26 at the transition between the first and second body portions 18a, 18 b. The shoulder portion 26 is present only on the front side 22 of the impact tool 16 for reasons that will be explained below. At the trailing side 24, the impact tool 16 tapers laterally inward from point A just past the transition between the first and second body portions 18a, 18 b.

The through bore 28 at the first end 20 is located within the first body portion 18a so that the impact tool 16 may be mounted to the rotor shaft 10 using conventional methods. The conventional method may include, for example, mechanical articulation.

In this embodiment, the wear member has a plurality of wear resistant teeth 30 arranged side-by-side along the front side 22 of the impact tool 16. By locating the wear resistant teeth 30 along the front side, the locations where the impact tool material wears most are protected. The wear resistant teeth 30 extend from a second end 32 of the impact tool 16 opposite said first end 20 towards said first end 20 up to a substantially intermediate position along the longitudinal extent of the impact tool 16.

In this case, six wear resistant teeth 30 are provided, but more or fewer wear resistant teeth may be used. The number of wear resistant teeth 30 and their physical extent along the length of the impact tool 16 depends on the anticipated wear scar or damage caused by the incoming polymer and can be adjusted accordingly.

Each tooth 30 is connected to the body 18 of the impact tool 16 by an engagement arrangement. In the present embodiment, the teeth 30 are joined to the body 18 by brazing. Alternatively, the wear teeth 30 may be removably mounted to the body for easy replacement.

Each tooth 30 is generally rectangular parallelepiped with a rounded leading edge 34. The first tooth in the row abuts the shoulder 26 between the first and second body portions 18a, 18 b. The last tooth in the row closest to the second end 32 is additionally curved inwardly toward the first end 20. The last tooth has a rounded outer edge 36 to complement the rounded leading edge. The wear teeth 30 are offset radially inwardly relative to the front side 22 so that they do not protrude beyond the second body portion 18b in the direction of rotation.

The rounded or chamfered edges relieve stress in critical areas of impact with the rock material, thereby preventing or at least limiting fracture of the impact tool 16. The use of a hemispherical surface on the front side may also work if rounded corners are not used.

Each tooth 30 comprises a wear resistant material such as cemented carbide (e.g. cemented tungsten carbide), polycrystalline diamond (PCD) material, cubic boron nitride (cBN), Polycrystalline Cubic Boron Nitride (PCBN) or ceramic.

A plurality of elongated protective ribs 38 project outwardly from an upper planar surface 40 of the impact tool. These ribs 38 serve to protect the impact tool body 18. Six ribs 38 are disposed in parallel and extend from the second end 32 to the human interface between the first and second body portions 18a, 18 b.

More or fewer ribs 38 may also be used. Alternatively, the ribs may extend over the impact tool body 18.

The ribs 38 comprise a low melting point carbide (LMC) material characterized as iron-based. Exemplary materials thereof are found in US8,968,834, US8,846,207 and US8,753,755. Alternatively, the ribs 38 may comprise cemented carbide or polycrystalline diamond (PCD) material, or other wear resistant material.

The following figures show variants of the impact tool. Like parts are indicated by like reference numerals, where appropriate. For the sake of brevity, only the main differences are described below.

Fig. 3 shows another embodiment of the impact tool, indicated at 42. In this embodiment, the wear teeth 44 are not offset inwardly relative to the front side 22. Unlike the embodiment shown in fig. 2, the wear teeth 42 protrude beyond the second body portion 18b in the direction of rotation.

Another difference is that the underside 46 of each wear tooth 42 is supported by the impact tool body 18. The body 18 includes a short support wall 48, the support wall 48 extending circumferentially outwardly from the underside of the second body portion 18 b. The support wall 48 reduces the risk of the wear teeth 42 being knocked off the body 18 when an entering rock strikes the impact tool 42 from above. Brazing is used to attach the wear resistant teeth 42 to the body 18. The thickness (measured axially) of the impact tool is increased to facilitate this connection.

Fig. 4 shows a further embodiment of an impact tool, indicated at 50, which is based on the embodiment of fig. 2, but has a width of about half of this embodiment.

In fig. 5, the width of another embodiment of the impact tool 52 is again reduced to about half that of the embodiment of fig. 4. Four wear resistant teeth 34 are provided, also connected to the body 18 of the impact tool 52 by an engagement arrangement.

In fig. 6, the impact tool 54 comprises an elongated block having a rectangular transverse cross-section. In this embodiment, the wear member is provided with a plurality of projections or studs 56 extending outwardly from the upper planar surface 40 of the impact tool 54. The protrusions 56 are arranged in an array on the surface 40, with regular spacing between them being a distinguishing feature. However, they may be configured to fit more closely, particularly but not necessarily near the second end 32. The projection 56 is an insert located in a correspondingly shaped recess in the surface 40.

The purpose of the protrusion 56 is to act as a protection for the substrate 25. They also improve the cutting efficiency of the impact tool. It is believed that the reduced lobe area (as compared to the body 18) concentrates the stresses in the rock to a greater extent than the otherwise flat surface of the body 18 when impacting with the incoming rock.

As with the wear part in any of the embodiments described herein, the material of the protrusion preferably comprises cemented carbide or polycrystalline diamond (PCD) material. Other wear resistant materials may also be used.

In this embodiment, insert 56 has a rounded profile at or above surface 40. It is contemplated that inserts having other shaped profiles may be used, for example, they may be parabolic or truncated. Also, the protrusion may be an insert in the shape of a sphere, hemisphere, cube, cuboid, or the like.

Brazing is used to secure the insert 56 to the body 18, but alternatively, press fitting, shrink fitting, gluing, or any other joining method may be used.

In fig. 7, the wear part is further provided with a plurality of protrusions 56. However, in the present embodiment, the impact tool 58 includes an elongated block having a trapezoidal transverse cross-section. The widest surface forms the lowermost surface of the impact tool 58. In addition to being disposed on the upper planar surface 40, the projections 56 are also disposed on the second planar surface 60. The second planar surface 60 is located on the front side 22 of the impact tool 58.

In fig. 8, the impact tool 62 includes an elongated block having a rectangular transverse cross section. In this embodiment, the wear member is provided in the form of a rectangular plate 64. A plurality of plates 64 arranged side-by-side extend on the upper planar surface of the impact tool 62 from the second end 32 toward the first end 20. The plate 64 extends to about 60% of the longitudinal length of the upper surface 40. Fig. 8 shows seven plates 64, but it will be apparent that more or fewer plates may be provided as desired. Brazing is used to attach each plate 64 to the body 18 of the impact tool 62, but other forms of attachment may be used.

In fig. 9 and 10, the impact tool 66 comprises an elongated block having a rectangular transverse cross-section. The wear resistant pieces are provided in the form of a carbide cap 68 covering a portion of the substrate 25 and a sleeve 70 covering a second (different) portion of the substrate 25 adjacent the first portion. The carbide cap 68 extends from the second end 32 toward the first end 20 and extends along approximately 30% of the longitudinal length of the impact tool 66. The sleeve 70 is a case hardened steel sleeve. The sleeve 70 has approximately the same length as the carbide cap 68, but is positioned along the middle of the impact tool 66 such that the overall length of the wear part is approximately 60% of the length of the impact tool 66.

In fig. 11, the impact tool 72 includes an elongated block having a rectangular transverse cross section. The wear part is provided in the form of a protective layer which extends partly through the substrate 25. The steel substrate is a strong core material that can withstand the impacts and vibrations imposed on the impact tool, while the protective layer provides abrasion resistance to reduce wear of the impact tool.

For the protective layer, a standard hard-facing or LMC material (described above) may be used. Various techniques can be used to obtain the desired material properties at or near the surface: nitriding, carburizing, case hardening, and/or laser treating.

The protective layer is provided in two different regions. The first region 74 has a first predetermined thickness and the second region 76 has a second predetermined thickness, wherein the second region 76 has a greater thickness than the first region 74. The second region 76 is located at a second end of the impact tool 72. This targeted layering process ensures that the protective layer is only placed where abrasion resistance is most needed, thereby reducing material costs.

While the present invention has been particularly shown and described with reference to embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.

Furthermore, although the rock material falling onto the impact tool is described as a polymer, it is not a limitation of the present invention. The invention may equally be used with polymers, agglomerated masses or any other type of rock or mineral of similar size and grain size.

Although the wear resistant teeth are described as extending over a portion of the width of the impact tool, the wear resistant teeth may alternatively extend over the entire width of the impact tool 16. In such embodiments, each wear tooth may include a retaining ring through which a locking pin passes to secure the wear tooth to the body of the impact tool.

In any of the embodiments described herein, the wear member may extend along the entire length of the impact tool (i.e., 100% of the longitudinal length) from the second end toward the first end of the impact tool. Optionally, the wear part may extend from the second end towards the first end of the impact tool along at most 90%, at most 80%, at most 70%, at most 60%, at most 50%, at most 40%, at most 30%, at most 20% or at most 10% of the longitudinal length of the impact tool.

Any combination of features of the various embodiments is contemplated. For example, the projections 56 may be used in conjunction with the wear teeth 30 as an alternative (or in addition) to the protective ribs 38.

The impact tools described herein have excellent wear and fracture resistance to incoming rocks and minerals processed through high speed, high impact energy pulverizers.

Certain standard terms and concepts used herein will be briefly explained below.

As used herein, polycrystalline diamond (PCD) material comprises a plurality of diamond grains, wherein a substantial number of the grains are directly bonded to one another, and the content of diamond is at least about 80 volume percent of the material. The interstices between the diamond particles may be substantially empty, or they may be at least partially filled with a filler material, or they may be substantially empty. The filler material may comprise a sintered catalytic material.

PCBN material comprises cubic boron nitride (cBN) grains dispersed in a matrix comprising a metal, semi-metal and/or ceramic material. For example, PCBN material may comprise at least about 30 volume% of cBN grains dispersed in a binder matrix material comprising a titanium-containing compound, such as titanium carbonitride and/or an aluminium-containing compound, such as aluminium nitride, and/or a metal (e.g. cobalt and/or tungsten) -containing compound. Certain types (or "grades") of PCBN material may comprise at least about 80 volume% or even at least about 85 volume% of cBN grains.