Wear resistant assembly for helically formed metal decanter auger

Abstract

The invention relates to a wear-resistant assembly for a helically formed metal screw conveyor of a decanter centrifuge. The assembly includes a wear plate defining a wear plate connection surface extending substantially in a longitudinal direction on a wear plate rear surface and a wear plate abutment surface extending substantially parallel to a wear plate top edge. The assembly further includes a back plate defining a back plate attachment surface on the back plate front surface for engagement with the wear plate attachment surface. The back plate further defines a back plate abutment surface on the back plate front surface for contacting the wear plate abutment surface when the back plate connection surface has engaged with the wear plate connection surface.

Description

Technical Field

[0001] The invention relates to a wear-resistant component for a helically formed metal conveyor screw of a decanting centrifuge, a helically formed metal conveyor screw for a decanting centrifuge and a method for mounting a wear-resistant component on a helically formed metal conveyor screw for a decanting centrifuge. Background Art

[0002] Decanter centrifuges are used in various applications to separate feed consisting of a solid-liquid mixture into light phase (liquid) and heavy phase (solid) components. Decanter centrifuges include a rotatable drum and a helically formed metal screw conveyor that can rotate around a common axis. The feed is typically injected at the center of the decanter centrifuge and separated into discharges at the opposite large and tapered ends of the drum, respectively. The light phase accumulates near the axis and is discharged at the large end, while the heavy phase accumulates at the inner surface of the drum wall and is conveyed to the outlet at the tapered end by the helically formed metal screw conveyor, which rotates at a speed slightly different from the rotation speed of the drum.

[0003] When the heavy phase is corrosive, there is a need to make the screw conveyor resistant to abrasion to extend the service life of the screw conveyor. For example, corrosive feeds are found in the mining industry (e.g. rock), the oil industry (e.g. sand) and the food industry (e.g. stone). The conveyor can be made resistant to abrasion by providing a wear plate of an abrasion-resistant material on the edge of the screw conveyor. Due to the corrosive nature of the feed, laser cladding or brazing of the wear plate is not preferred. It is preferred to attach the wear plate purely mechanically to the backing plate to form an assembly. The assembly can then be attached to the edge of the screw conveyor by fastening the backing plate to the edge of the screw conveyor by welding, brazing or similar fastening techniques.

[0004] CN 204249388 describes a centrifugal decanter having a ceramic element connected to a supporting body by means of a dovetail connection.

[0005] US 8523751 describes a screw centrifuge comprising a series of thin ceramic plates fixed adjacent to each other on the outer edge of the screw. The plate has at least two formed ceramic projections, which protrude from the thin ceramic plate and are arranged in a recessed portion contoured according to the projections.

[0006] GB 2130508 describes a spiral centrifuge with a wear plate having an elastic rubber between the wear plate and the support plate. It may also have a needle-shaped extension.

[0007] US 5429581 describes a centrifugal decanter having a wear resistant component with a dovetail projection having a threaded opening.

[0008] US 6230960 describes a centrifuge with a tile having a dovetail portion.The tile carrier comprises a dovetail slot or groove defined between mutually facing upper and lower lips adapted to engage with the lip of the tile in use.

[0009] KR 1020170013456 describes a tile body and a tile tip, each having a fixing protrusion and a fixing hole on one side. The fixing protrusion and the fixing hole are combined with each other.

[0010] US2006 / 0046081 describes a multi-layer laminated anti-wear assembly comprising a bracket laminated between plates of anti-wear material. The layers of the assembly are secured together by soldering, brazing or some other method. The bracket material is stuck between two layers of harder material and remains stretched between the two layers of harder material.

[0011] WO 2014 / 183772 describes a centrifugal decanter with tile dovetail locking. The support plate has an opening into which the wear-resistant tile is inserted. The opening forms an upper corner, allowing the male corner of the wear-resistant tile to be inserted.

[0012] GB 2048728 and US 4328925 both describe a centrifugal decanter having an anti-wear component with a mating surface that mechanically connects the anti-wear component to a back plate. The mating surface prevents radially outward movement of the anti-wear component.

[0013] WO 9413403 describes a centrifugal decanter with a wear-resistant component mounted along the edge of a screw conveyor. The component has a dovetail projection on its rear surface. The projection tapers in radial direction in width. The component can be directly engaged with its corresponding back plate by sliding movement substantially in radial direction to the axis of the screw.

[0014] GB 2273253B relates to a conveyor screw having a back plate and tiles joined to the back plate by radial sliding movement. Each tile is held in radial inward movement only by abutment with an adjacent tile.

[0015] Having a mating surface that mechanically connects the wear component to the back plate and prevents radial outward movement of the erosion component can cause the erosion component to become loose if the wear plate wears to the mating surface. In this case, the wear component can be thrown toward the inner surface of the drum wall, possibly causing serious damage to the drum wall.

[0016] Having a dovetail protrusion that tapers in width in the radial direction can keep the wear plate in place even when the anti-wear component wears. However, since the tapered protrusion points in the radial direction toward the drum wall, the tapered protrusion is sensitive to manufacturing tolerances. Small deviations in the measurement of the tapered protrusion can cause large deviations in the radial direction of the wear plate. As a result, the wear plate may extend too far in the radial direction and may cause damage to the inner wall of the drum.

[0017] It is therefore an object of the present invention to provide a technique which avoids the above mentioned drawbacks of the prior art. Summary of the invention

[0018] The above objects are achieved in a first aspect by a wear-resistant assembly for a helically formed metal screw conveyor for a decanting centrifuge, the assembly comprising:

[0019] a wear plate defining a wear plate front surface and a wear plate rear surface, the wear plate rear surface defining a wear plate top edge, a wear plate bottom edge, and two oppositely positioned wear plate side edges interconnecting the wear plate top edge and the wear plate bottom edge, the wear plate rear surface further defining a longitudinal direction extending from the bottom edge to the top edge, the wear plate defining a wear plate connecting surface extending substantially in the longitudinal direction on the wear plate rear surface and a wear plate abutment surface extending substantially parallel to the wear plate top edge on the wear plate rear surface, and

[0020] A back plate defining a back plate front surface and a back plate rear surface, the back plate rear surface being attachable to the helically formed metal screw conveyor, the back plate defining a back plate connecting surface on the back plate front surface for engaging with the wear plate connecting surface, the back plate further defining a back plate abutment surface on the back plate front surface for contacting the wear plate abutment surface when the back plate connecting surface has engaged with the wear plate connecting surface.

[0021] The wear-resistant assembly is attached side by side on the edge of the spirally formed metal screw conveyor of the decanting centrifuge. The wear-resistant plate has a connection surface extending substantially in the longitudinal direction. The wear-resistant plate connection surface mainly faces the side edge of the wear-resistant plate. When the front surface of the back plate is engaged with the wear-resistant plate connection surface, the wear-resistant plate connection surface faces and engages the back plate connection surface to keep the rear surface of the wear plate from moving in a direction away from the front surface of the back plate, that is, to prevent separation between the wear plate and the back plate. The wear-resistant plate connection surface and the back plate connection surface should be appropriately formed to prevent such separation when the wear-resistant plate connection surface and the back plate connection surface are engaged. The wear-resistant plate connection surface faces and engages the back plate connection surface to also keep the wear plate from moving left and right, that is, moving left and right in the direction between the side edges.

[0022] When the back plate connection surface has engaged with the wear plate connection surface, the back plate abutment surface will contact the wear plate abutment surface for holding the wear plate relative to the back plate in the longitudinal direction. Since the wear plate abutment surface extends substantially parallel to the top edge of the wear plate, the wear plate abutment surface provides a well-defined stop for the wear plate relative to the back plate, preventing the top edge from extending too far toward the inner wall of the drum. The distance between the top edge of the wear plate and the inner wall of the drum can therefore be determined and controlled very accurately. Small manufacturing errors on the plate will only have a small effect on the distance between the top edge and the inner wall of the drum. In contrast, if the distance between the top edge of the wear plate and the inner wall of the drum is determined by the contact between the tapered wear plate connection surface extending substantially in the longitudinal direction and the back plate connection surface, small manufacturing errors on the plate will have a large effect on the distance between the top edge and the inner wall of the drum.

[0023] The back plate abutment surface is preferably complementary to the wear plate abutment surface such that it contacts the wear plate abutment surface along a contact line substantially parallel to the wear plate top edge.The wear plate abutment surface is preferably located adjacent the top edge, however, it may also be located adjacent the lower edge.

[0024] According to a further embodiment of the first aspect, the back plate connecting surface engages with the wear plate connecting surface by a sliding movement between the wear plate rear surface and the back plate front surface in a longitudinal direction of the wear plate.

[0025] The sliding movement allows the wear plate connecting surface and the back plate connecting surface to engage in a simple and secure manner and allows the wear plate abutment surface to contact the back plate abutment surface.

[0026] According to a further embodiment of the first aspect, the backing plate connection surface and the wear plate connection surface define a protrusion and a groove of complementary shape in which the protrusion engages.

[0027] The protrusions of the engaging grooves hold the rear surface of the wear-resistant plate from moving in a direction away from the front surface of the backing plate, ie, prevent separation between the wear-resistant plate and the backing plate.

[0028] According to a further embodiment of the first aspect, the protrusions are provided on the wear plate and the grooves are formed in the back plate.

[0029] Thereby, the wear plate is supported by the backing plate, which is beneficial because the wear plate is typically more brittle than the backing plate.

[0030] According to a further embodiment of the first aspect, the protrusion has a dovetail cross-section.

[0031] The raised dovetail cross section will hold the rear surface of the wear plate from moving in a direction away from the front surface of the backing plate, ie, prevent separation between the wear plate and the backing plate.

[0032] According to a further embodiment of the first aspect, the protrusions and the grooves taper in width in the longitudinal direction.

[0033] In this way, the wear plate will be restrained in the longitudinal direction even if the wear plate abutment surface and the back plate abutment surface are polished. This allows the wear plate abutment surface to be positioned close to the top edge of the wear plate. When the wear plate abutment surface is polished, the movement of the wear plate relative to the back plate in the longitudinal direction will be limited by the contact of the wear plate connection surface with the back plate connection surface. This will prevent the wear plate from becoming loose and thrown towards the inner surface of the drum wall even if the wear plate abutment surface and the back plate abutment surface are polished. When the abutment surfaces are polished, there will be a small movement of the wear plate relative to the back plate in the longitudinal direction due to the contact of the wear plate connection surface with the back plate connection surface.

[0034] According to another embodiment of the first aspect, the assembly further comprises a locking plate which can be attached to the backing plate at the bottom edge of the wear plate when the wear plate engages the backing plate for retaining the wear plate relative to the backing plate in a direction from the top edge of the wear plate toward the bottom edge of the wear plate.

[0035] In order to hold the wear plate relative to the back plate in the direction opposite to the longitudinal direction, a locking plate may be used. The wear plate will be positioned between the locking plate and the inner wall of the drum and will therefore not come into significant contact with the solid portion of the feed material and therefore it will not wear significantly. Preferably, the locking plate maintains pressure on the bottom edge of the wear plate in the longitudinal direction to ensure that the wear plate abutment surface contacts the back plate abutment surface. The locking plate may be spot welded to the back plate.

[0036] According to a further embodiment of the first aspect, the locking plate comprises a protrusion which protrudes into a complementary groove in the wear plate when the wear plate engages the backing plate.

[0037] The tabs and complementary grooves may be used to ensure that the wear plate is locked in a central position relative to the backing plate and / or prevent any side-to-side movement.

[0038] According to another embodiment of the first aspect, a rubber film is provided between the wear plate and the back plate, the rubber film being preferably applied by spraying on the wear plate rear surface and / or the back plate front surface.

[0039] Having a rubber membrane between the wear plate and the backing plate provides some flexibility in the assembly, which may avoid cracking of the wear plate.

[0040] According to a further embodiment of the first aspect, the back plate comprises a wear indicator on the rear surface.

[0041] The wear indicators may be in the form of markings or ribs which wear away and thus indicate when the wear resistant component should be replaced.

[0042] According to a further embodiment of the first aspect, the top edge is between 10 mm and 100 mm, preferably between 25 mm and 75 mm.

[0043] The wear resistant component should preferably have the above measurements to be able to fit in a typical decanter centrifuge.

[0044] According to another embodiment of the first aspect, the backing plate is made of a softer material than the wear plate, the wear plate is preferably made of carbide such as tungsten carbide, ceramic, polyurethane or polyurea, and the backing plate is preferably made of steel such as stainless steel.

[0045] The wear plate may be made of a harder material than the back plate for resisting abrasion. The back plate may be made of a softer material for attachment to the edge of the helically formed metal screw conveyor by welding, brazing or the like. The above materials are suitable as the wear plate and the back plate, respectively.

[0046] The above object is achieved in a second aspect by a helically formed metal screw conveyor for a decanting centrifuge, the helically formed metal screw conveyor comprising one or more wear-resistant components according to any embodiment of the first aspect, wherein the rear surface of the backing plate is attached to the edge of the helically formed metal screw conveyor, and the longitudinal direction corresponds to the direction radially outward from the axis of the helically formed metal screw conveyor.

[0047] The wear resistant assembly is first mechanically assembled and then attached at the top edge of the helically formed metal auger. The backing plate is fastened to the helically formed metal auger, while the wear plate should face in an outward direction on the helically formed metal auger relative to the axis of rotation. Typically, several wear resistant assemblies are assembled and attached along the edge of the helically formed metal auger.

[0048] According to a further embodiment of the second aspect, the wear-resistant assembly is attached to the helically formed metal screw conveyor by means of a weld at an edge of the helically formed metal screw conveyor.

[0049] The back plate of the assembly is typically attached by a weld at the edge of the metal auger. An additional weld may be made at the front surface of the helically formed metal auger, at the intersection between the back plate and the helically formed metal auger, opposite the top edge. Preferably, MMA, TIG or MAG welding may be used.

[0050] The above objects are achieved in a third aspect by a method for mounting a wear-resistant assembly on a helically formed metal screw conveyor for a decanting centrifuge, the assembly comprising:

[0051] a wear plate defining a wear plate front surface and a wear plate rear surface, the wear plate rear surface defining a wear plate top edge, a wear plate bottom edge, and two oppositely positioned wear plate side edges interconnecting the wear plate top edge and the wear plate bottom edge, the wear plate rear surface further defining a longitudinal direction extending from the bottom edge to the top edge, the wear plate defining a wear plate connecting surface extending substantially in the longitudinal direction on the wear plate rear surface and a wear plate abutment surface extending substantially parallel to the wear plate top edge on the wear plate rear surface, and

[0052] a back plate defining a back plate front surface and a back plate rear surface, the back plate rear surface being attachable to the helically formed metal auger, the back plate defining a back plate connecting surface on the back plate front surface, the back plate further defining a back plate abutment surface on the back plate front surface,

[0053] The method comprises performing the following steps:

[0054] engaging the backing plate connection surface with the wear plate connection surface, and,

[0055] The back plate abutment surface is brought into contact with the wear plate abutment surface.

[0056] The method according to the third aspect preferably uses a wear plate assembly according to any embodiment of the first aspect. For example, the wear plate is preferably joined to the backing plate by sliding movement. Other steps may include welding a locking plate to the backing plate. The assembly is then welded to a helically formed metal screw conveyor. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1A is a perspective view of a helically formed metal screw conveyor.

[0058] Figure 1B is a close-up perspective view of the wear-resistant components.

[0059] Figure 2A is a side view of a wear-resistant assembly according to a first embodiment.

[0060] Figure 2B is a perspective view of the installation procedure for the wear plate.

[0061] Figure 2C is a second perspective view of the installation procedure for the wear plate.

[0062] Figure 3A Side view showing the locking procedure of the wear plates.

[0063] Figure 3B Perspective view showing the locking procedure of the wear plate

[0064] Figure 3C A second perspective view showing the locking procedure of the wear plates.

[0065] Figure 4A A side view of the wear assemblies shown engaged and locked.

[0066] Figure 4B A perspective view showing the wear assemblies engaged and locked.

[0067] Figure 4C A second perspective view of the wear assemblies is shown engaged and locked.

[0068] Figure 5 A third perspective view of the wearable assembly is shown in a non-engaged and unlocked state.

[0069] Figure 6 A perspective view of an alternative embodiment of a wear resistant assembly is shown. DETAILED DESCRIPTION

[0070] Figure 1A A decanter centrifuge 10 is shown having a helically formed metal conveyor screw 12 which is positioned within a cylindrical bowl 14 of the decanter centrifuge 10 . Figure 1B The position of the wear-resistant assembly 16 is shown in a close-up view of FIG.

[0071] The auger 12 is provided with a plurality of wear assemblies 16 positioned at the outer edge 18 of the auger 12. Each wear assembly 16 includes a wear plate 20, a backing plate 22 and a locking plate 24. The wear assemblies 16 are first assembled and then secured to the outer edge 18 of the auger 12.

[0072] The wear plate 20 includes a wear plate front surface 26 and an opposing wear plate rear surface (not visible) that is mechanically secured to a front surface (not visible) of the backing plate 22. The wear plate front surface 26 includes a top edge 28, a bottom edge 30, and two opposing side edges 32, 34 interconnecting the top edge 28 and the bottom edge 30.

[0073] The wear plate 20 is mechanically secured to the back plate 22 so that the wear plate top edge 28 is positioned adjacent to but avoids contact with the drum wall 14. The locking plate 24 is secured to the back plate 22 adjacent to the bottom edge 30, typically by spot welding. The locking plate 24 holds the wear plate 20 in place. The wear assembly 16 is then welded to the auger 12 by a weld (not shown) at the outer edge 18 of the helically formed metal auger. An additional weld (not shown) may be made at the front surface of the helically formed metal auger 12, at the intersection between the back plate 22 and the helically formed metal auger 12, opposite the outer edge 18. Preferably, MMA, TIG or MAG welding may be used.

[0074] The backing plate 22 also includes a wear indicator 36 that indicates wear on the wear resistant component 16. The wear indicator 22 includes a protrusion that polishes as the wear resistant component 16 wears as an indication of wear.

[0075] The wear plate 20 is made of a wear resistant material such as tungsten carbide, ceramic, polyurethane or polyurea, and the backing plate 22 is made of a weldable material such as steel, typically stainless steel. The locking plate 24 is typically made of the same weldable material as the backing plate 22. The wear plate 20 protects the backing plate 22 and the helically formed metal auger 12 from excessive wear.

[0076] Figure 2A A side view of the wear assembly 16 according to the first embodiment is shown together with the edge 18 of the auger. The wear plate 20 is joined to the back plate 22 as indicated by the arrows. The rear surface 38 of the wear plate 20 is mechanically mounted on the front surface 40 of the back plate 22. The back plate 22 is welded to the auger at the outer edge.

[0077] Figure 2B A perspective view of the engagement procedure of the wear plate 20 onto the backing plate 22 is shown. The rear surface 38 of the wear plate 20 includes a protrusion 46 of the rear surface 38. The protrusion 46 has a dovetail shape that tapers toward the wear plate top edge 28. The protrusion 46 engages with a complementary groove (not visible) on the backing plate front surface (not visible) by a sliding motion as shown by the arrows. The protrusion 46 includes two opposing wear plate connecting surfaces 42 extending along the side edges 32, 34 and a wear plate abutment surface 44 extending substantially parallel to the top edge 28 of the wear plate 20.

[0078] Figure 2C A second perspective view of the engagement process of the wear plate 20 onto the backing plate 22 is shown. The backing plate front surface 40 includes two opposing backing plate connection surfaces 48 extending along the side edges 32, 34 and a backing plate abutment surface 50. The front surface 40 of the backing plate 22 includes a groove 52 that is complementary to the protrusion (not visible) of the wear plate 20, and the protrusion (not visible) on the wear plate rear surface (not visible) engages in the groove 52 as shown by the arrow. In this way, the wear plate 20 engages the backing plate 22.

[0079] When the protrusion (not visible) engages the groove, the wear plate connection surface (not visible) faces and engages the back plate connection surface for holding the wear plate rear surface 38 from moving in a direction away from the back plate front surface 40, i.e., preventing separation between the wear plate 20 and the back plate 22. This is performed by the dovetail configuration of the protrusion 46 and the complementary shape of the groove 52.

[0080] When the back plate connection surface 48 has engaged the wear plate connection surface (not visible), the wear plate abutment surface (not visible) contacts the back plate abutment surface 50 for retaining the wear plate 20 relative to the back plate 22 in a longitudinal direction extending from the bottom edge 30 to the top edge 28 .

[0081] Figure 3A A side view of the locking procedure of the wear plate 20 relative to the backing plate 22 in the opposite longitudinal direction by using a locking plate 54 is shown. The locking plate 54 includes a protrusion 56 that is inserted into a complementary opening 58 of the wear plate 20. The locking plate 54 is inserted in the direction as shown by the arrow and can be held in the opposite longitudinal direction to the wear plate bottom edge 30 with pressure to ensure that the wear plate abutment surface contacts the backing plate abutment surface. The locking plate 54 is then spot welded to the backing plate 22.

[0082] Figure 3B A perspective view of the locking procedure of the wear plate 20 relative to the backing plate 22 in the opposite longitudinal direction is shown. The protrusion 56 of the locking plate 54 has a tapered shape that is complementary to the opening (not visible) in the wear plate 20. Thus, the protrusion 56 and the opening 58 help both to secure the wear plate 20 in the longitudinal direction and to center the wear plate 20 on the backing plate 22 when inserted as shown by the arrow.

[0083] Figure 3C A second perspective view is shown of the locking procedure of the wear plate 20 relative to the backing plate 22 whereby the locking plate 54 is moved as indicated by the arrows.

[0084] Figure 4A A side view of the engaged and locked wear assembly 16 secured to the outer edge 18 of the auger 12 is shown. The wear plate 20 is mechanically secured to the backing plate 22 and locked in place by the locking plate 54. The locking plate 54 is typically spot welded to the backing plate 22. The wear assembly 16 is then welded to the auger 12 by a weld 60 where the outer edge 18 of the helically formed metal auger intersects the backing plate 22, and an additional weld 60 at the front surface of the helically formed metal auger 12, opposite the outer edge 18 at the intersection between the backing plate 22 and the helically formed metal auger 12. Preferably, MMA, TIG or MAG welding may be used.

[0085] Figure 4B A perspective view of the engaged and locked wear assembly 16 is shown, ready to be secured to the rim 18 of the auger.

[0086] Figure 4C A second perspective view of the engaged and locked wear assembly 16 is shown, ready to be secured to the rim 18 of the auger.

[0087] Figure 5 A perspective view of the wear assembly 16' is shown in a non-engaged and unlocked state. The present locking plate 54 has an inclined edge 50', which corresponds to the other inclined edge 30' of the wear plate 20. The inclined edges contact to ensure an even better mechanical connection between the wear plate 20, the backing plate 22 and the locking plate 54'.

[0088] The engagement and locking procedure is the same as in the previous embodiment: in a first step indicated by the circular arrow, the back plate connection surface 46 engages with the wear plate connection surface 42, and in a second step indicated by the straight arrow, when the locking plate 54 is attached to the back plate 22, the back plate abutment surface 50' contacts with the wear plate abutment surface 44.

[0089] Figure 6 A perspective view of an alternative embodiment of the wear assembly 16' is shown in a non-engaged and unlocked state. In this embodiment, the protrusion 46' has a different shape with a wear plate abutment surface 44' located closer to the bottom edge 30. The wear plate abutment surface 44' is still parallel to the top edge 28, but is located along the corresponding wear plate connection surface 42'. The corresponding groove 52' has a corresponding different shape, which defines a back plate abutment surface 50' along the back plate connection surface 48'.

Claims

1. A wear-resistant assembly for a helically formed metal screw conveyor of a decanting centrifuge, the assembly comprising: a wear plate defining a wear plate front surface and a wear plate rear surface, the wear plate rear surface defining a wear plate top edge, a wear plate bottom edge, and two oppositely positioned wear plate side edges interconnecting the wear plate top edge and the wear plate bottom edge, the wear plate rear surface further defining a longitudinal direction extending from the bottom edge to the top edge, the wear plate defining a wear plate connecting surface on the wear plate rear surface extending substantially in the longitudinal direction and a wear plate abutment surface on the wear plate rear surface extending substantially parallel to the wear plate top edge, and A back plate defining a back plate front surface and a back plate rear surface, the back plate rear surface being attachable to the helically formed metal screw conveyor, the back plate defining a back plate connecting surface on the back plate front surface for engaging with the wear plate connecting surface, the back plate further defining a back plate abutment surface on the back plate front surface for contacting the wear plate abutment surface when the back plate connecting surface has engaged with the wear plate connecting surface.

2. The wear-resistant assembly according to claim 1, wherein: The back plate connection surface engages with the wear plate connection surface by sliding movement between the wear plate rear surface and the back plate front surface in the longitudinal direction of the wear plate.

3. A wear-resistant component according to any one of the preceding claims, wherein: The back plate connection surface and the wear plate connection surface define projections and complementary shaped grooves in which the projections engage.

4. The wear-resistant assembly according to claim 3, wherein: The protrusions are provided on the wear plate, and the grooves are formed in the back plate.

5. The wear-resistant component according to any one of claims 3 or 4, wherein: The projection has a dovetail cross-section.

6. The wear-resistant component according to any one of claims 3 to 5, wherein: The protrusions and the grooves taper in width in the longitudinal direction.

7. A wear-resistant component according to any one of the preceding claims, wherein: The assembly further includes a locking plate which can be attached to the backing plate at the bottom edge of the wear plate when the wear plate engages the backing plate for retaining the wear plate relative to the backing plate in a direction from the top edge of the wear plate toward the bottom edge of the wear plate.

8. The wear-resistant assembly according to claim 7, wherein: The locking plate includes a protrusion that projects into a complementary opening in the wear plate when the wear plate engages the backing plate.

9. A wear-resistant component according to any one of the preceding claims, wherein: A rubber film is provided between the wear plate and the back plate, the rubber film being preferably applied by spraying on the wear plate rear surface and / or the back plate front surface.

10. A wear-resistant component according to any one of the preceding claims, wherein: The back plate includes a wear indicator on the rear surface.

11. A wear-resistant component according to any one of the preceding claims, wherein: The top edge is between 10 mm and 100 mm, preferably between 25 mm and 75 mm.

12. A wear-resistant component according to any one of the preceding claims, wherein: The backing plate is made of a softer material than the wear plate, which is preferably made of carbide such as tungsten carbide, ceramic, polyurethane or polyurea, and the backing plate is preferably made of steel such as stainless steel.

13. A helically formed metal screw conveyor for a decanting centrifuge, comprising one or more wear resistant components according to any one of the preceding claims, wherein the back plate rear surface is attached to the edge of the helically formed metal screw conveyor and the longitudinal direction corresponds to the direction radially outward from the axis of the helically formed metal screw conveyor.

14. The helically formed metal screw conveyor for a decanting centrifuge according to claim 13, wherein: The wear resistant assembly is attached to the helically formed metal auger by a weld at an edge of the helically formed metal auger.

15. A method of installing a wear resistant assembly on a helically formed metal screw conveyor for a decanting centrifuge, the assembly comprising: a wear plate defining a wear plate front surface and a wear plate rear surface, the wear plate rear surface defining a wear plate top edge, a wear plate bottom edge, and two oppositely positioned wear plate side edges interconnecting the wear plate top edge and the wear plate bottom edge, the wear plate rear surface further defining a longitudinal direction extending from the bottom edge to the top edge, the wear plate defining a wear plate connecting surface on the wear plate rear surface extending substantially in the longitudinal direction and a wear plate abutment surface on the wear plate rear surface extending substantially parallel to the wear plate top edge, and a back plate defining a back plate front surface and a back plate rear surface, the back plate rear surface being attachable to the helically formed metal auger, the back plate defining a back plate connection surface on the back plate front surface, the back plate further defining a back plate abutment surface on the back plate front surface, The method comprises performing the following steps: engaging the backing plate connection surface with the wear plate connection surface, and, The backing plate abutment surface is brought into contact with the wear plate abutment surface.

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