WO2007105039A2

WO2007105039A2 - Lining arrangement

Info

Publication number: WO2007105039A2
Application number: PCT/IB2006/054007
Authority: WO
Inventors: Berend Jan Werkman
Original assignee: Berend Jan Werkman
Priority date: 2006-03-15
Filing date: 2006-10-30
Publication date: 2007-09-20
Also published as: ZA200610210B; WO2007105039A3; AU2006340292A1; WO2007105038A2; AU2006340291A1; WO2007105038A3; ZA200610209B

Abstract

The invention provides a lining arrangement, suitable for use in lining a surface to be shielded against abrasive material, the lining arrangement including an outer wall having a shielded surface; and a lining member extending from the shielded surface at a downward inclination; a mounting angle between the lining member and the shielded surface being smaller than 30° so as to result in abrasive material impinging on the lining member to be induced to at least partially roll relative to the lining member.

Description

LINING ARRANGEMENT

FIELD OF THE INVENTION

The invention relates to lining members and a lining arrangement for a surface to be lined utilizing such lining members. More particularly, but not exclusively, the invention relates to lining members for lining receptacles and/or surfaces for use in storing and/or conveying abrasive material, such as mineral ore, and to a lining arrangement utilizing such lining members, such as skips, chutes and dump trucks.

BACKGROUND TO THE INVENTION

Many applications exist where abrasive material needs to be conveyed and stored. In mining applications ore is frequently conveyed as part of the mining process. The conveyed ore often consists of a wide range of rock fragments that vary in size from a fraction of a millimeter to rocks of up to 500mm in diameter. In applications where the ore have not been screened the ore may include even larger rocks. The rock fragments often have sharp edges, and may also be of irregular shapes having sharp protrusions. It will be appreciated that the ore described above causes excessive wear when impacting on a conveyance surface.

The wear is particularly severe in the case of mine skips, ore chutes and dump trucks, as ore is typically dropped into such receptacles from elevated positions, thus increasing the impact of the ore on the load-bearing surfaces. The non-vertical angle of entry of ore into such receptacles also results in substantial forces impacting on the sidewalls of such receptacles, and the problem of high impact-loading is therefore not only limited to bottom and lower walls of such receptacles.

It will be appreciated that it would be advantageous if the impact imparted by ore on load-bearing surfaces can be reduced. Various methods have in the past been proposed to facilitate the same.

Angularly inclined impingement plates, known in the trade as cascades, are sometimes secured to the surfaces to be protected, in order to protect the surface against impacting rock. However, a number of disadvantages are associated with known cascades, including the shortcoming that heavy structures are required to support the cascades due to excessive forces being exerted thereon. This becomes problematic in applications such as mine skips where the weight of the receptacle is critical.

The conventional cascades used to protect receptacles, in particular mining skips, have a downward sloping angle relative to the receptacle wall of between 45° and 30°. The angle at which ore is discharged from chutes into the receptacle is between 30° and 45° from the vertical, because rock starts flowing freely off a flat steel surface sloped at more than 45° from the horizontal. The resulting impingement angle of the rock flow on the face of the cascade is therefore between about 60° and 90°, The cascades are normally made of steel and are mostly protected by hard wear liners.

Rubber cascades mounted on steel backing plates are also used in industry. When rubber cascades are used, the aim is to achieve an impingement angle of close to 90° to allow maximum shock absorption and to prevent the rocks from cutting into the rubber surface. Some of these rubber cascades have been observed to be steel clad to protect the rubber from the cutting action of the rocks.

It is known that wear, both on rubber and steel, is much lower during rolling contact than during sliding contact. As a result known cascades aim to achieve impingement angles approximating 90° so that the rocks bounce and roll off the cascades, rather than slide along the cascades. Published data also shows that impact wear against steel is most severe at an angle of incidence of about 32°, and existing designs therefore avoid this situation.

Various other configurations are known in industry, which are also aimed at inducing a rolling action on ore. Raised strips at right angles to the flow of rock fragments can for instance induce such a rolling action. Examples of such configuration are shown in United States Patents No US 6,000,741 and US 6,007,132. These configurations however form small dead zones which is not advisable in applications where efficient discharge of loads are required, as is for instance the case with mining skips and dump trucks.

OBJECT OF THE INVENTION

It is accordingly an object of the invention to provide a lining arrangement that will at least partially alleviate the abovementioned disadvantages.

It is also an object of the invention to provide a lining arrangement that will provide a useful alternative to existing lining arrangements. SUMMARY OF THE INVENTION

According to the invention there is provided a lining arrangement, suitable for use in lining a surface to be shielded against abrasive material, the lining arrangement including: an outer wall having a shielded surface; and a lining member extending from the shielded surface at a downward inclination; a mounting angle between the lining member and the shielded surface being smaller than 30° so as to result in abrasive material impinging on the lining member to be induced to at least partially roll relative to the lining member.

Preferably the mounting angle is smaller than 20°, and more preferably the mounting angle is between 10° and 15°. In a preferred embodiment the mounting angle is 12°.

There is also provided for the abrasive material to impinge on the lining member at an impingement angle of between 30° and 55°, more preferably between 35° and 40° and in a preferred embodiment at an angle of 37°.

In a preferred embodiment the mounting angle is 12° and the impingement angle is 37°.

There is also provided for a backing member to be located between the lining member and the shielded surface.

Preferably the backing member is made of elastomeric material. The backing member may be at least partially tapered.

There is also provided for an oblique support bracket to extend from the shielded surface, the backing member being located between the support bracket and the lining member. An outer surface of the support bracket may be substantially parallel to the lining member.

The lining member includes a connecting section, which is substantially parallel relative to the shielded surface, and an impingement section, which is angularly displaced relative to the shielded surface.

Securing apertures may be provided in the connecting section for securing the lining member to the shielded surface.

The connecting section of the lining member may be secured to the shielded surface by way of threaded securing means.

The backing member may include a planar connecting zone of reduced thickness, the connecting zone being adapted to locate between the connecting section of the lining member and the shielded surface, so as to be sandwiched therebetween when the lining member is secured to the shielded surface.

The lining member may also include an end section that extends from the impingement section, the end section being substantially parallel to the shielded surface and to the connecting section. Securing apertures may be provided in the end section for securing the lining member to the shielded surface.

The end section of the lining member may be secured to the shielded surface by way of threaded securing means.

The backing member may include a planar end zone, the end zone being adapted to locate between the end section of the lining member and the shielded surface, so as to be sandwiched therebetween when the lining member is secured to the shielded surface.

The backing member may include an intermediate zone on the outer surface of the intermediate zone being angularly displaced relative to the connecting zone and/or the end zone of the backing member so as to abut the lining section of the lining member when sandwiched between the lining member and the shielded surface.

There is also provided for the lining member to be at least partially displaceable relative to the shielded surface. In a preferred embodiment there is provided for the lining member to be at least partially pivotable about the threaded securing means that secure the connecting section of the lining member to the shielded surface.

The securing apertures for receiving the threaded securing means preferably have a larger diameter than shanks of the threaded securing means, so as to allow displacement between the lining members and the threaded securing means, and as such between the lining member and the shielded surface. The threaded securing means may be in the form of securing bolts, and the securing bolts may be secured to the shielded surface by way of lock nuts.

There is further provided for the lining member to be made of a metal. In a preferred embodiment welding material may be applied to an outer surface of the metal lining member. Preferably the welding material is applied in spaced apart rows, and more preferably the spaced apart rows are directed in the direction of movement of the abrasive material relative to the lining member.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described by way of non-limiting examples, and with reference to the accompanying drawings, in which:

Figure 1 is a cross-sectional side view of a lining arrangement in accordance with the invention;

Figure 2 is a cross-sectional side view of a lining arrangement in accordance with a further embodiment of the invention;

Figure 3 is a cross-sectional side view of a lining arrangement in accordance with a further embodiment of the invention; and

Figure 4 is a perspective view of the lining arrangement of figure 3 as applied to the inside of a mining skip. DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings, in which like numerals indicate like features, non-limiting examples of a lining arrangement in accordance with the invention is indicated by reference numeral 10.

The lining arrangement 10 comprises a plurality of lining members 20 that are secured to an outer wall 15 of a receptacle or conveyance arrangement that is exposed to abrasive material, so as to protect a shielded surface 16 of such outer wall 15. The outer wall 15 may for instance be a wall of a mining skip, an ore dump truck or a conveyance chute.

The abrasive material (represented by arrow A) enters the receptacle at an angle relative to the outer wall 15, and thus the shielded surface 16. The entry angle (β) is typically between 45° and 30° from a vertical axis. The lining member 20 is mounted to the outer wall 15 at a downward inclination, and a mounting angle (α) is defined between the lining member 20 and the shielded surface 16. The abrasive material impinges on the lining member 20 at an impingement angle (θ), which is the relative angle between the entry angle (β) and the mounting angle (α).

In this embodiment the impingement angle (θ) is approximately 37° degrees, which angle is the result of a mounting angle (α) of 12° and an entry angle (β) of 25° degrees. It is however foreseen that the mounting angle may be between 10° and 29°. A resilient backing member 30 is sandwiched between the lining member 20 and the shielded surface 16. The backing member 30, which is made of an elastomeric material, aids in absorbing impact loads on the lining member 20.

In the arrangement utilized in Figure 1 , the backing member 30 is substantially triangular, and includes a planar connecting zone 31 of reduced thickness and an intermediate zone 32 being of tapered configuration. The backing member 30 abuts the shielded surface 16 on one side thereof, and abuts a lining member 20 on an opposing side. More particularly, the intermediate zone 32 of the backing member 30 abuts the impingement section 22 of the lining member 20, whereas the connecting zone 31 of the backing member 30 abuts a connecting section 21 of the lining member.

The lining member 20, as well as the backing member 30, includes securing apertures 24, and the lining member is secured to the shielded surface 16 by way of threaded connecting means 50 in the form of threaded bolts, in so doing trapping the backing member 30 between the shielded surface 16 and the lining member 20. The threaded bolt is secured by way of a lock nut 51 , which ensures that the threaded bolt remains secured even if the tension imparted by the backing member 30 is reduced. The securing apertures 24 have larger diameters than shanks of the threaded bolts 50, so as to allow the lining member 20 to be displaceable relative to the shielded surface 16, thus enabling compression of the backing member 30 in absorbing impact forces exerted on the lining member 20.

Figure 2 shows an embodiment similar to that of figure 1 , but includes a tapered support bracket 40 that is secured to the shielded surface 16. In this embodiment the backing member 30 has a substantially planar intermediate zone 32. A preferred embodiment of the invention is shown in figures 3 and 4. This embodiment is similar to that disclosed in figure 1 hereinbefore, but the lining member 20 also includes an end section 23 that is parallel to the connecting section 21 , and thus to the shielded surface 16. Likewise, the backing member 30 includes an end zone which is substantially planar, and which is adapted to abut the shielded surface 16 as well as the end section 23 of the lining member 20. In this embodiment the threaded securing means 50 is perpendicular to the shielded surface 16 at both ends of the lining member 20, thus simplifying the process of securing the lining member 20 to the shielded surface 16. In use, a plurality of lining arrangements 10 are positioned end-to-end on an outer wall 15 of a receptacle or conveyance surface to be protected, as is shown in figure 4.

The lining member 20 is typically made of metal, and may include rows of welding material 60 applied to a surface thereof. The rows are typically aligned with the direction of flow of the abrasive material, and are spaced apart in sixteen (16) millimeter intervals. Each row of welding material 60 is about eight (8) millimeters wide. The inventor has found that the rows of welding material provides good protection against sliding wear from large rocks forming part of the abrasive material, without adding much weight to the lining members 20.

Corner sections 80 are located closer to the shielded surface 16 than the lining members 20, due to a backing member 30 of reduced thickness being used behind the corner sections 80. In this embodiment ends of the lining members 20 overlie the receded corner sections 80, and no overlying lip formations are required. The inventor has found that the optimal configuration is to use one single lining member 20 that spans the length of one of the sides of the shielded surface 16, as this provides an arrangement of optimal structural strength. A lining member 20 will therefore span from one corner up to an adjacent corner. Also, the inventor has found that the particular partially Z-shaped configuration of the lining member 16 shown in the figures increases the bending moment, and thus the structural strength, of the lining member 16, and therefore of the composite wall comprising the outer wall 15 and the lining member 16. This allows one to reduce the thickness of the outer wall 15, thus saving material and reducing the overall weight of the receptacle.

The inventor has carried out a number of trials and experiments in order to arrive at the embodiments as described hereinbefore. The invention results in light structures, which are still structurally strong enough to withstand larger rocks that normally form part of the abrasive material, and which will at the same time also provide good wear resistance.

Impact tests against the inclined lining members, or cascades, have been carried out by the inventor using different sizes of rock selected from typical run of mine rock fragments. The angle and velocity of the rocks flowing from the typical discharge chutes were used, and the angles of the lining members or cascades were varied. The impact was recorded on high-speed video camera, while the forces caused by the impact were simultaneously recorded by means of strain gauges and very high frequency recording and computing equipment.

Contrary to the prior art, as set out in the background to the invention hereinbefore, the inventor has found the surprising result that in use the lining members experiences less wear at smaller relative impingement angles. More particularly, it was found that wear is minimised at about 37°. The inventor found that as the impingement angle was reduced, the nature of the impact changed from a rolling and bouncing action, to a partially sliding and rolling action, and that the impact forces were therefore substantially lower when the sliding occurred. The inventor also found that the direction in which the rocks rolled changed when sliding occurred, but that the lining members nevertheless induced a rolling action on the rocks. During the tests, the sliding contact of individual rocks was also observed to cause more wear than the rolling contact. It was however surprisingly found that the smaller rocks maintained their bouncing and rolling action at smaller angles than when compared to the larger rocks.

Trials under normal operating conditions with run of mine ore also showed lower wear on the lining members at smaller relative contact angles. It is submitted that the rationale behind this phenomenon is the fact that only a small proportion of the rocks in run of mine ore are large, and that the smaller rocks and fines form the bulk of the run of mine ore and thus the abrasive material. The small rocks therefore roll and bounce off the lining members at the 37° impingement angle, thus causing little wear while the sliding wear of the large rocks is not that significant in total. It was also found that the 37° impingement angle had the added advantage of reducing impact loads experienced by the lining members. The supporting structure for the lining members can therefore also be made lighter should this particular angle be used.

The inventor still further found that in a container having a series of such lining members secured to the container wall, the smaller rocks were found to bounce off the surface of the lining members and to rotate. The rotation of the smaller rocks in a downwardly directed stream of rocks was found to cause the rocks to impact and rub against each other as well as against the liner members lower down in the container, thereby slowing down the speed of the rock flow, and thus reducing wear in the container. The rolling action induced on the larger rocks by the 37° impingement angle similarly caused slowing down of the large rocks, although the rotation was in an opposite direction to that of the smaller rocks.

When the rubber backing was introduced behind the lining members, the inventor found that the impact loads were even further reduced, which resulted in still lower wear and a further possibility to reduce the mass of the container.

The inventor has found that this invention can be used to produce a container, receptacle or conveyance surface for abrasive material which is lighter than existing receptacles and/or containers, whilst also having a longer operational life span due to the enhanced wear resistance. The invention may find application in many different environments including mining skips, any other mobile container, dump trucks, conveyance chutes and any other surface being exposed to abrasive material, especially under potential impact loads.

It will be appreciated that the above are only some embodiments of the invention, and that there may be many variations without departing from the spirit and/or the scope of the invention.

Claims

CLAIMS:

1. A lining arrangement, suitable for use in lining a surface to be shielded against abrasive material, the lining arrangement including: an outer wall having a shielded surface; and a lining member extending from the shielded surface at a downward inclination; a mounting angle between the lining member and the shielded surface being smaller than 30° so as to result in abrasive material impinging on the lining member to be induced to at least partially roll relative to the lining member.

2. The lining arrangement of claim 1 wherein the mounting angle is smaller than 20°.

3. The lining arrangement of claim 2 wherein the mounting angle is between 10° and 15°.

4. The lining arrangement of claim 3 wherein the mounting angle is 12°.

5. The lining arrangement of any one of the preceding claims wherein the abrasive material impinges on the lining member at an impingement angle of between 30° and 55°.

6. The lining arrangement of claim 5 wherein the impingement angle is between 35° and 40°.

7. The lining arrangement of claim 6 wherein the impingement angle is 37°.

8. The lining arrangement of any one of the preceding claims wherein a backing member is located between the lining member and the shielded surface.

9. The lining arrangement of claim 8 wherein the backing member is made of elastomeric material.

10. The lining arrangement of any one of claims 8 or 9 wherein the backing member is at least partially of a tapered configuration.

11. The lining arrangement of any one of claims 8 or 9 wherein the lining arrangement includes an oblique support bracket that extends from the shielded surface, the backing member being located between the support bracket and the lining member.

12. The lining arrangement of claim 11 wherein an outer surface of the support bracket is substantially parallel to the lining member.

13. The lining arrangement of any one of the preceding claims wherein the lining member includes a connecting section, which is substantially parallel relative to the shielded surface, and an impingement section, which is angularly displaced relative to the shielded surface.

14. The lining arrangement of claim 13 wherein securing apertures are provided in the connecting section for securing the lining member to the shielded surface.

15. The lining arrangement of claim 14 wherein the connecting section of the lining member is secured to the shielded surface by way of threaded securing means.

16. The lining arrangement of any one of claims 13 to 15 wherein the backing member includes a planar connecting zone of reduced thickness, the connecting zone being located between the connecting section of the lining member and the shielded surface, so as to be sandwiched therebetween when the lining member is secured to the shielded surface.

17. The lining arrangement of any one of claims 13 to 16 wherein the lining member includes an end section that extends from the impingement section, the end section being substantially parallel to the shielded surface and to the connecting section.

18. The lining arrangement of claim 17 wherein securing apertures are provided in the end section for securing the lining member to the shielded surface.

19. The lining arrangement of claim 18 wherein the connecting section of the lining member is secured to the shielded surface by way of threaded securing means.

20. The lining arrangement of any one of claims 17 to 19 wherein the backing member includes a planar end zone, the end zone being adapted to locate between the end section of the lining member and the shielded surface, so as to be sandwiched therebetween when the lining member is secured to the shielded surface.

21. The lining arrangement of any one of claims 8 to 19 wherein the backing member includes an intermediate zone, with an the outer surface of the intermediate zone being angularly displaced relative to the connecting zone and/or the end zone of the backing member so as to abut the lining section of the lining member when sandwiched between the lining member and the shielded surface.

22. The lining arrangement of any one of the preceding claims wherein the lining member is at least partially displaceable relative to the shielded surface.

23. The lining arrangement of claim 22 wherein the lining member is at least partially pivotable about the threaded securing means that secures the connecting section of the lining member to the shielded surface.

24. The lining arrangement of any one of the preceding claims wherein the lining member is made of a metal.

25. The lining arrangement of claim 24 wherein welding material is applied to an outer surface of the metal lining member.

26. The lining arrangement of claim 25 wherein the welding material is applied in spaced apart rows.

27. The lining arrangement of claim 26 wherein the spaced apart rows are directed in the direction of movement of the abrasive material relative to the lining member.