Composite metal centrifugal slurry pump impeller

Abstract

A composite metal centrifugal slurry pump impeller includes a rear cover having opposing inner and outer surfaces, the rear cover having an outer peripheral edge and a central axis, and a plurality of pumping blades extending away from the inner main surface of the rear cover. The pumping blades are arranged in a spaced-apart relationship, each pumping blade including opposing main sides, a leading edge in a region of the central axis, and a trailing edge in a region of the outer peripheral edge of the rear cover. A channel is provided between adjacent pumping blades, wherein one or more cavities are located in the rear cover, in a region of at least one of the channels, and wherein a wear-resistant component is at least partially incorporated within the one or more cavities.

Description

Technical Field

[0001] This disclosure relates in general to a composite metal slurry pump impeller. Background Technology

[0002] The various processing steps in the mineral processing industry involve corrosive contact with equipment components, leading to severe wear to the point of requiring frequent replacement. However, depending on the nature of the processing steps, component wear is often uneven.

[0003] For example, in the process of using a centrifugal slurry pump to pump grinding slurry, the limiting factor for the wear life of the wet end components of the centrifugal slurry pump can be localized wear in certain locations of the slurry pump impeller in the form of deep planing or very high wear rates, even if other parts of the impeller may wear at a relatively low rate.

[0004] The present invention seeks to provide a relatively low-cost composite metal slurry pump impeller that provides an impeller for use in the mineral processing industry, including local wear protection. Summary of the Invention

[0005] According to one aspect, a centrifugal slurry pump impeller is provided, the centrifugal slurry pump impeller including a rear cover having opposing inner and outer surfaces, the rear cover having an outer peripheral edge and a central axis, and a plurality of pumping blades extending away from the inner main surface of the rear cover, the pumping blades being arranged in a spaced-apart relationship, each pumping blade including opposing main sides, a leading edge in a region of the central axis and a trailing edge in a region of the outer peripheral edge of the rear cover, and a channel between adjacent pumping blades, wherein one or more cavities are located in the rear cover, in a region of at least one of the channels, and wherein a wear-resistant component is at least partially incorporated within the one or more cavities.

[0006] In some embodiments, the one or more cavities are formed in the outer surface of the rear cover, whereby the wear-resistant component is not exposed to the channel between adjacent pumping blades. In one form, the one or more cavities include sidewalls and endwalls, wherein the endwalls are spaced apart from the surface of the inner main surface of the rear cover. In another form, the endwalls are located within approximately 5 mm to approximately 25 mm from the surface of the inner main surface of the rear cover.

[0007] In some embodiments, the one or more cavities include a circular opening, cylindrical sidewalls, and a circular endwall.

[0008] In some embodiments, the width of the end wall of the one or more cavities spans at least 50% of the width of the channel between adjacent pumping blades. In one embodiment, the width of the end wall of the one or more cavities spans at least 75% of the width of the channel between adjacent pumping blades. In another embodiment, the width of the end wall of the one or more cavities spans a distance that substantially covers the width of the channel between adjacent pumping blades.

[0009] In some embodiments, the wear-resistant component substantially fills the one or more cavities. In one form, the wear-resistant component is cylindrical. In another form, the diameter of the wear-resistant component is greater than its height. In yet another form, the wear-resistant component is disc-shaped and corresponds to the shape of the one or more cavities.

[0010] In some embodiments, a plug portion is also located within the one or more cavities, wherein the plug portion covers the wear-resistant component located within the one or more cavities. In one form, the plug portion includes an outer surface that is substantially flush with or in the same plane as the outer surface of the rear cover.

[0011] In some embodiments, the one or more cavities include sidewalls and endwalls, wherein the sidewalls include contact portions on the outer side of the rear cover, wherein the contact portions are spaced apart from the surface of the inner main surface of the rear cover. In one form, the one or more cavities include cylindrical sidewalls and circular endwalls.

[0012] In some embodiments, the contact portion of the sidewall is located within approximately 5 mm to approximately 25 mm of the surface of the inner main surface of the rear cover. In one form, the contact portion spans at least 50% of the width of the channel between adjacent pumping blades. In another form, the contact portion spans at least 75% of the width of the channel between adjacent pumping blades.

[0013] In some embodiments, during use, the lengths of the sidewalls and the contact portions are oriented perpendicular to the flow direction through the channel.

[0014] In some embodiments, during use, the lengths of the sidewall and the contact portion lie in a plane perpendicular to the axis of rotation of the pump impeller.

[0015] In some embodiments, the length of the sidewall and the contact portion substantially spans the channel from one pumping blade to another.

[0016] In some embodiments, the diameter of the wear-resistant component is smaller than its height.

[0017] In some implementations, each channel includes at least two cavities located between one pumping blade and another pumping blade.

[0018] In some embodiments, each channel includes three cavities positioned at intervals along the length of each channel. In one form, the three cavities are located at the first two-thirds of the length of each channel.

[0019] In some embodiments, the one or more cavities are formed in the inner surface of the rear cover, thereby exposing the wear-resistant component to the channel between adjacent pumping blades.

[0020] In one embodiment, the one or more cavities include sidewalls and endwalls, wherein the endwalls are spaced apart from the surface of the outer main surface of the rear cover. In another embodiment, the endwalls are located within approximately 5 mm to approximately 25 mm from the surface of the outer main surface of the rear cover. In one embodiment, the one or more cavities include a circular opening, cylindrical sidewalls, and a circular endwall.

[0021] In some embodiments, the one or more cavities are inclined from the plane of the rear cover, wherein when the slurry pump impeller is in use, the wear-resistant components combined within the cavities are at an angle to the flow direction of the slurry.

[0022] In some embodiments, each channel includes two or more cavities formed in the inner surface of the rear cover. In one form, each channel includes an inner region and an outer region, the inner region beginning near the leading edge of the plurality of pumping blades and ending midway along each channel, the outer region beginning midway along each channel and ending near the outer peripheral edge, wherein the one or more cavities are substantially located in the inner region of each channel.

[0023] In some embodiments, the abrasion-resistant component is located above the surface of the inner surface of the rear cover. In one form, the abrasion-resistant component is cylindrical, cubic, or button-shaped. In another form, the height of the shape of the abrasion-resistant component is greater than its diameter.

[0024] In some embodiments, the wear-resistant component is bonded to the one or more cavities using an adhesive or by brazing.

[0025] In some embodiments, the slurry pump impeller is made of high-chromium white cast iron.

[0026] In some embodiments, the wear-resistant component is selected from tungsten carbide.

[0027] In some embodiments, the pump impeller includes a front shroud with an inner main surface, wherein the plurality of pumping blades extend between the inner main surfaces of the rear shroud and the front shroud.

[0028] In some embodiments, the wear-resistant components are gradually exposed as the pumping blades are worn during the operation of the centrifugal slurry pump.

[0029] In some embodiments, the one or more cavities include a circular opening and truncated conical sidewalls. In one form, the wear-resistant component is truncated conical in shape.

[0030] In some embodiments, the one or more cavities in the region of the channel extend from the outside of the rear cover to the inside of the rear cover.

[0031] Other aspects, features, and advantages will become apparent from the following detailed description taken in conjunction with the accompanying drawings, which are part of this disclosure and illustrate the principles of the disclosed invention by way of example. Attached Figure Description

[0032] The accompanying diagrams facilitate understanding of the various implementation schemes.

[0033] Figure 1 This is a schematic diagram of the front cross-section of a slurry pump impeller used in centrifugal slurry pumps;

[0034] Figure 2 This is a perspective view of a slurry pump impeller for a centrifugal slurry pump according to one embodiment;

[0035] Figure 3 yes Figure 2 A cross-sectional view of the passage of the impeller of a centrifugal slurry pump shown.

[0036] Figure 4 This is a cross-sectional view of a slurry pump impeller for a centrifugal slurry pump according to another embodiment;

[0037] Figure 5 This is a partial perspective view of the inlet of the impeller of a centrifugal slurry pump according to another embodiment;

[0038] Figure 6 This is a front cross-sectional schematic diagram of a slurry pump impeller for a centrifugal slurry pump according to another embodiment;

[0039] Figure 7 yes Figure 6 The diagram shows a cross-sectional view of the impeller passage of a centrifugal slurry pump.

[0040] Figure 8This is a front cross-sectional view of a centrifugal slurry pump impeller according to one embodiment, which depicts the location of the cavity below the inner surface of the rear cover;

[0041] Figure 9 yes Figure 8 A perspective view of the centrifugal slurry pump impeller from the inlet opening and the channel inlet;

[0042] Figure 10 yes Figure 8 and Figure 9 A cross-sectional view of the impeller of a centrifugal slurry pump shows the location of the cavity inside the rear cover below the surface of the channel;

[0043] Figure 11 This is a cross-sectional view of the passage of a slurry pump impeller for a centrifugal slurry pump according to another embodiment;

[0044] Figure 12 This is a cross-sectional view of the passageway of a slurry pump impeller for a centrifugal slurry pump according to another embodiment; and,

[0045] Figure 13 This is a cross-sectional view of the passage of a slurry pump impeller for a centrifugal slurry pump according to another embodiment. Detailed Implementation

[0046] Using the methods described herein, it has been discovered that composite metal slurry pump impellers can be manufactured for use as wear components in centrifugal slurry pumps in the mineral processing industry. Specifically, it has been found that when one or more cavities are formed during the casting process of the slurry pump impeller, these cavities do not substantially affect the structural integrity of the impeller and also allow wear-resistant components in solid form to be bonded and / or fixed into the one or more cavities to produce composite metal slurry pump impellers with enhanced wear resistance.

[0047] In some embodiments, a composite metal slurry pump impeller is provided, which may be composed of a matrix metal component including a wear-resistant material bonded to and / or fixed within a cavity formed during the casting process of the matrix metal component. Alternatively, the cavity may be formed after the casting process by machining the cavity into the matrix metal component.

[0048] The cavity is formed within the matrix metal component, and the resulting composite slurry pump impeller is composed of the matrix metal component and a wear-resistant material. The wear-resistant material may be bonded or fixed within the cavity, which may be located within the main body of the slurry pump impeller composed of the matrix metal component, adjacent to or near the channel located between the pumping blades.

[0049] In some embodiments, the wear-resistant material is positioned such that it is encapsulated within the body of the composite metal slurry pump, wherein the main working surface of the composite metal slurry pump is composed of a matrix metal component. This ensures that the working surface of the slurry pump is not hydrodynamically altered by the inclusion of the wear-resistant material. In this embodiment, the wear-resistant material is exposed as the body of the metal wear component begins to wear during use, thereby reducing the wear rate experienced by the metal wear component.

[0050] In an alternative embodiment, the wear-resistant component is contained within a cavity located on the main working surface of the composite metal slurry pump impeller, such as in the channels between the pumping blades of the slurry pump impeller. In this form, the wear-resistant material has a top surface that is recessed or flush (in a straight line) with the inner surface of the shroud of the pump impeller located in the channels between the pumping blades. Alternatively, the wear-resistant material may be located above the surface of the inner surface of the shroud, to a degree that the impact of the wear-resistant material does not substantially affect the hydrodynamic performance of the slurry pump impeller shape.

[0051] Composite metal slurry pump impellers can be manufactured using methods for producing composite metal components, such as those described in, for example, WO 2019 / 119043, the contents of which are incorporated herein by reference.

[0052] The base metal composition can be selected from any suitable metal or metal alloy suitable for casting wear parts, such as high-chromium white cast iron. The wear-resistant component ideally has increased wear resistance compared to the base metal composition and can be selected from materials with very high wear resistance, such as tungsten carbide. Tungsten carbide can be sintered and / or can have a grain size of 2 to 6 micrometers. In preferred forms, the wear-resistant component is cylindrical, cubic, or button-shaped, or has another commonly manufactured shape. It has been found that commonly manufactured forms such as cylindrical, cubic, or button shapes are generally cheaper than other more irregular shapes, which reduces the cost of producing composite metal slurry pump impellers as described herein.

[0053] In one embodiment, an adhesive is used to bond the wear-resistant component into one or more cavities in the matrix metal. The adhesive may have high gap-filling capacity and high tensile strength. For example, the adhesive may be selected from LOCTITE EA9497 or 3M Scotch-weld 7236B / A or other structural epoxy adhesives; or high-strength retention compounds such as Loctite 620, Loctite 638 or Loctite 660.

[0054] Alternatively, the wear-resistant component can be bonded to one or more cavities using a brazing method. As another alternative, or in addition to the bonding examples described above, the wear-resistant component can be bonded or secured to one or more cavities via a mechanical locking device, such as a threaded plug, shrink-fit plug, or tight-fit plug that holds the compound in place by high strength; these measures are intended to prevent the wear-resistant component from dislodging from its fixed cavity during operation of the slurry pump impeller.

[0055] refer to Figure 1 The diagram shows a cross-section of a known centrifugal slurry pump impeller 10, which includes a rear shroud 11 having four pumping blades 12 that extend from the shroud in a direction substantially aligned with the axis of rotation X of the slurry pump impeller during operation. This causes the pump impeller to... Figure 1 The rotation is counterclockwise as shown. The inner surface 15 of the rear cover is generally in a plane perpendicular to the axis of rotation X. Each of the four pumping blades 12 includes a trailing edge 13 and a leading edge 14, wherein the leading edge 14 of the pumping blade is adjacent to the center or orifice 16 of the impeller 10, through which slurry enters during the operation of the associated centrifugal slurry pump (not shown). The slurry passes through the orifice and then moves through four channels 6 located between adjacent pumping blades 12 due to the orientation and rotation of the slurry pump impeller. The pumping blades 12 also include opposing main sides 7, 8, which are adjacent to the rear cover 11 and the front cover 21 ( Figure 1 The inner surfaces 15 and 17 (not shown) together define the channel 6. The position and function of the four channels 6 mean that this section of the slurry pump impeller 10, especially the area of ​​the channel 6 along the inner surface 15 of the rear cover 17, is subject to severe erosion and wear during the operation of the centrifugal slurry pump, which means that the inner surface 15 of the rear cover 17 is a highly worn location.

[0056] refer to Figures 2 to 4 Various views of the impeller 10 of the composite metal slurry pump are shown. Figure 2 A perspective view is shown from the rear or drive side of the slurry pump impeller, showing the outer surface 18 of the rear cover 11. The outer surface 18 of the rear cover 11 includes four cavities 20 formed in the matrix metal composition that forms the body of the composite metal slurry pump. These cavities are equidistantly spaced around the outer surface of the rear cover. Each of the cavities 20 includes a wear-resistant component 25 incorporated within each cavity 20.

[0057] For details, please refer to the following: Figure 3 and Figure 4As can be seen, cavity 20 is located within the rear cover 11 in the region of channel 6 of slurry pump impeller 10, which is defined as the space between two adjacent pumping blades 12. The cavity includes end walls 23, side walls 24, and an opening 22. When the slurry pump impeller is manufactured not to expose channel 6, the wear-resistant component 25 is located within cavity 20 and then bonded to it. This means that when the slurry pump impeller is initially put into service, the wear-resistant component will not affect the hydrodynamic performance of the slurry pump impeller 10 during operation.

[0058] The wear-resistant component 25 corresponds to the shape of the cavity 20 and can be cylindrical or disc-shaped, wherein the diameter of the wear-resistant component 25 is significantly larger than its height. This results in the diameter of the cavity 20 and the wear-resistant component 25 being at least 50% of the cross-section of the channel 6 located between the respective pumping blades 12, and at least 75% in a preferred embodiment. Because the cavity 20 and the wear-resistant component 25 are located in the region of the channel 6, once the inner surface of the rear cover 11 forming the channel 6 begins to wear during the use of the slurry pump impeller 10, wear gradually exposes the surface of the wear-resistant material 25 bonded to the cavity 20. Once exposed, the wear-resistant component 25 slows down the wear rate in the region of the channel 6, thereby extending the service life of the composite metal slurry pump impeller 10. When initially manufactured, the wear-resistant component may be located approximately 5 mm to 25 mm below the surface of the inner surface of the rear cover 11.

[0059] like Figure 4 As shown, the disc-shaped plug portion 26 can also be located on top of the wear-resistant component 25 and held in place by an adhesive, piston ring, or multi-threaded connection. The plug portion 26 is constructed of a material such as high-chromium cast iron, which is quite wear-resistant because it will be exposed to abrasion conditions on the outside of the rear cover when the slurry pump impeller 10 is in use. The shape of the cavity 20 may include a narrow-diameter portion for receiving the wear-resistant component 20, followed by a wider-diameter portion for receiving the plug portion 26. This arrangement appears in… Figure 4 The implementation scheme on the right side is shown. Figure 4 An alternative arrangement is shown on the left side, wherein the cavity 20 has a uniform diameter and the plug portion 26 has a diameter larger than that of the wear-resistant component and includes a side portion of the sidewall 24 adjacent to the cavity, which encapsulates or covers the sidewall of the wear-resistant component 23.

[0060] Figure 5 , Figure 6 and Figure 7 Another embodiment of the composite metal slurry pump impeller 10 according to this disclosure is shown. See details. Figure 6A cross-sectional perspective view of the impeller 10 is shown, with the front cover removed, revealing the channels 6 on the inner surface of the pumping blades 12 and the rear cover 11 located between the pumping blades 12. Multiple cavities 20 are shown in each of the channels 6 of the impeller 10, each including an opening 20, a sidewall 24, and an endwall 23. Although in Figure 5 and Figure 6 Not shown, but the aforementioned method can be used to incorporate the wear-resistant component in the form of a cylindrical insert into the cavity. The cavity 20 extends through the thickness of the rear cover 11 until there is approximately 5 mm to approximately 75 mm between the bottom of the cavity 20 and the outer surface of the rear cover 11. Alternatively, the cavity may extend through approximately one-third to approximately four-fifths of the thickness of the rear cover 11.

[0061] refer to Figure 7 As can be seen, the shape and orientation of cavity 20 can be tilted from the plane of the rear cover, wherein the wear-resistant component 25 incorporated within cavity 20 forms an angle with or against the slurry flow direction when the slurry pump impeller 10 is in use. In other words, when facing the flow direction through the passage from the leading edge through the impeller, a line perpendicular to the central axis of cavity 20 forms an angle with the surface of the inner surface of the rear cover 11. This angle can be approximately 50° to approximately 85° or approximately 70° to approximately 80°.

[0062] exist Figure 6 As can be seen, when located in the channel, the cavities are grouped in rows and located in the inner region 30 of the channel 6, not in the outer region 31. It has been found that by positioning the cavities 20 and the wear-resistant component 25 in the inner region 30 of the channel 6, a significant reduction in wear in this region of the rear cover is provided. Adding cavities and wear-resistant components in the outer region 31 of the channel 6 does not result in a significant improvement in wear resistance, which ensures the increase in production costs involved.

[0063] Once placed within cavity 20, the top surface of the wear-resistant component 25 can be recessed, flush, substantially flush, or only slightly raised above the inner surface of the rear cover 11. During use, the wear-resistant component significantly reduces the wear rate in the inner region of the channel, which improves the service life of the composite metal slurry pump impeller 10.

[0064] Figure 8 , Figure 9 and Figure 10 Another embodiment of the composite metal slurry pump impeller 10 according to this disclosure is shown. (Reference) Figure 8 The diagram shows a cross-sectional view of the impeller 10 with the front cover removed, revealing the pumping blades 12 and channels 6 on the inner surface of the rear cover 11 located between the pumping blades 12. Each channel 6 includes the outline of three cavities 20 located below the surface of the channel 6 on the inner surface of the rear cover 11.

[0065] lie in Figure 8 , Figure 9 and Figure 10 The cavity 20 in the impeller shown is cylindrical in shape and includes a circular end wall 24 and cylindrical side walls. The cylindrical side walls include... Figure 10 The contact portion 34 is best shown in the diagram. Contact portion 34 is a part of the outermost sidewall furthest from the rear cover 11 and a part of the sidewall 24 closest to the inner surface of the rear cover 11, which forms the channel 6 between the pumping blades 12 of the impeller 10. Contact portion 34 may be spaced apart from the surface of the inner main surface of the rear cover 11. In a preferred embodiment, the contact portion 34 of the sidewall may be located within approximately 5 mm to approximately 25 mm from the surface of the inner main surface of the rear cover.

[0066] The length of the sidewall 24 and the contact portion 34 of the cavity 20 can span a considerable distance from one opposite side 7 of the pumping blade 12 to the other opposite side. In a preferred embodiment, the contact portion 34 of the cavity 24 may be located over most of the width of the passage from one opposite side 7 of the pumping blade 12 to the other opposite side 8, and preferably over the entire width.

[0067] like Figure 8 and Figure 9 As shown, when the impeller 10 is in use, the lengths of the sidewalls 24 and contact portions 34 of each component in the cavity 20 can be oriented perpendicular to the flow direction through the channel. When the pump impeller is in use, the lengths of the sidewalls 24 and contact portions 34 can also be located in a plane perpendicular to the axis of rotation.

[0068] When the slurry pump impeller is manufactured so as not to be exposed in the channel 6, the wear-resistant component 25 is located within the cavity 20 and then bonded within that cavity. This ensures that when the slurry pump impeller is initially put into use, the wear-resistant component does not affect the hydrodynamic performance of the slurry pump impeller 10 during operation.

[0069] The wear-resistant component 25 corresponds to the shape of the cavity 20 and can be cylindrical, wherein the height of the wear-resistant component 25 is significantly greater than its width. This results in the length of the sidewalls and contact portions of the cavity 20 and the wear-resistant component 25 being at least 50% of the cross-section of the channel 6 located between the respective pumping blades 12, and at least 75% in a preferred embodiment. Since the cavity 20 and the wear-resistant component 25 are located within the area of ​​the channel 6, once the inner surface of the rear cover 11 forming the channel 6 begins to wear during the use of the slurry pump impeller 10, the surface of the wear-resistant material 25 bonded within the cavity 20 at the contact portion 34 is gradually exposed. Once the wear-resistant component 25 is exposed, it slows down the wear rate in the area of ​​the channel 6 immediately downstream of the wear-resistant component 25 (towards the outer edge of the rear cover), thereby extending the service life of the composite metal slurry pump impeller 10. When the impeller 10 is initially manufactured, the wear-resistant component 25 may be located approximately 5 mm to 25 mm below the surface of the inner surface of the rear cover 11.

[0070] like Figure 8 and Figure 9 As shown, in the illustrated embodiment, each channel 6 may include at least two cavities 20, and each channel 6 may include three cavities 20. The cavities 20 may be spaced apart along the length of the channel 6, and in a preferred form, the cavities are located at the first two-thirds of the length of each channel, starting from the leading edge of the pumping blade 12.

[0071] refer to Figure 11 , Figure 12 and Figure 13 Three additional embodiments of the composite metal slurry pump impeller 10 are shown. In each embodiment, the impeller 10 includes a cavity 20 formed in the matrix metal composition forming the body of the composite metal slurry pump impeller 10 outside a rear cover 11. Each of the cavities 20 includes a wear-resistant component 25 bonded within each cavity 20. The cavity 20 is located within the rear cover 11 in the region of a passage 6 of the slurry pump impeller 10, which is defined as the space between two adjacent pumping blades 12.

[0072] Figure 11 , Figure 12 and Figure 13 Each of the cavities shown includes a sidewall 24 and an opening 22. However, only Figure 12 The illustrated embodiment includes an end wall 23 of cavity 20, wherein when the slurry pump impeller is manufactured not to be exposed to channel 6, wear-resistant component 25 is located within cavity 20 and then bonded within the cavity.

[0073] Figure 11 and Figure 13 The cavity 20 shown is in an alternative configuration in which the cavity extends just through the body of the rear cover 11 to the surface of the channel 6. This allows the wear-resistant component 25 to be incorporated within the cavity 20, such that the wear-resistant component is flush with or just above the surface of the channel 6 on the inner main surface of the rear cover 11.

[0074] The wear-resistant component 25 corresponds to the shape of the cavity 20, and can be as follows: Figure 12 and Figure 13 The cylindrical shape shown, or as Figure 11 The truncated conical shape shown. The truncated conical shape of wear-resistant component 25 corresponds to... Figure 11 The shape of the sidewall 24 of the cavity 20 is shown. The truncated conical shape of the cavity and the corresponding truncated conical shape of the wear-resistant component 25 incorporated within the cavity 20 provide increased resistance to movement between the matrix metal and the wear-resistant component during the use of the impeller 10, as the matrix metal component begins to wear. It is also possible to provide... Figure 11 An alternative embodiment of the shown embodiment, wherein the end wall is disposed in a truncated conical cavity, such that when the impeller 10 is initially manufactured, the wear-resistant component is located below the surface of the channel on the inner surface of the rear cover.

[0075] Since the cavity 20 and the wear-resistant component 25 are located in the area of ​​the channel 6, once the inner surface of the rear cover 11 forming the channel 6 begins to wear during the use of the slurry pump impeller 10, the wear gradually exposes the surface of the wear-resistant material 25 bonded to the cavity 20. Once the wear-resistant component 25 is exposed, it slows down the wear rate in the area of ​​the channel 6, thereby extending the service life of the composite metal slurry pump impeller 10.

[0076] The disc-shaped plug portion 26 can also be located in Figure 11 , Figure 12 and Figure 13 The wear-resistant component 25 is placed on top of the cavity 20 and held in place by an adhesive, piston ring, or multi-threaded connection. The plug portion 26 may be large enough to cover more than one cavity, and preferably at least two to six openings 22 of the cavity 20. The plug portion 26 may be made of a material such as high-chromium cast iron, which is quite wear-resistant because the plug portion will be exposed to wear conditions on the outside of the rear cover when the slurry pump impeller 10 is in use.

[0077] In the foregoing description of some embodiments, specific terms have been used for clarity. However, this disclosure is not intended to be limited to the specific terms so chosen, and it should be understood that each specific term includes other technical equivalents that operate in a similar manner to achieve similar technical purposes. Terms such as “left” and “right,” “front” and “back,” “up” and “down” are used as convenient words to provide a point of reference and should not be construed as restrictive terms.

[0078] In this specification, the word "including" should be understood in its "open" meaning, that is, the meaning of "containing", and is therefore not limited to the "closed" meaning, which is the meaning of "consisting of only". If the corresponding words "including", "containing", and "having" appear, the corresponding meaning is also considered to be the attribute of the corresponding words "including", "containing", and "having".

[0079] Furthermore, the foregoing only illustrates some implementation schemes, which may be changed, modified, added to and / or altered without departing from the scope and substance of the disclosed implementation schemes. These implementation schemes are illustrative and not restrictive.

[0080] Furthermore, the invention has been described in conjunction with embodiments currently considered to be the most practical and preferred. It should be understood that the invention is not limited to the disclosed embodiments, but rather, it is intended to encompass various modifications and equivalent arrangements included within the spirit and scope of the invention. Moreover, the various embodiments described above can be implemented in combination with other embodiments; for example, aspects of one embodiment can be combined with aspects of another embodiment to implement other embodiments. Furthermore, each individual feature or component of any given component can constitute an additional embodiment.

[0081] Parts list Channel 6 Relative side 7, 8 Top surface 9 Impeller 10 Back cover 11 Pump blade 12 Trailing edge 13 Frontier 14 15mm inner surface of the rear cover Impeller orifice 16 17 on the inner surface of the front cover 18 on the outside of the back cover Cavity 20 Front cover 21 Opening 22 End wall 23 Side wall 24 Abrasion-resistant component 25 Part 26 Inner area 30 Outer Area 31 Front cover 21 Opening 22 Contact part 34

Claims

1. A composite metal centrifugal slurry pump impeller comprising a rear cover having opposing inner and outer surfaces, the rear cover having an outer peripheral edge and a central axis, a plurality of pumping blades extending remotely from the inner surface of the rear cover, the pumping blades being arranged in a spaced-apart relationship, each pumping blade including opposing main sides, a leading edge in a region of the central axis and a trailing edge in a region of the outer peripheral edge of the rear cover, a channel being provided between adjacent pumping blades, wherein one or more cavities are located in the rear cover, in a region of at least one of the channels, and wherein a wear-resistant component is at least partially incorporated within the one or more cavities, wherein the one or more cavities are formed in the outer surface of the rear cover, thereby preventing the wear-resistant component from being exposed to the channel.

2. The centrifugal slurry pump impeller according to claim 1, wherein the one or more cavities include sidewalls and endwalls, wherein the endwalls are spaced apart from the surface of the inner surface of the rear cover.

3. The centrifugal slurry pump impeller according to claim 1, wherein the one or more cavities include a circular opening, a cylindrical sidewall, and a circular endwall.

4. The centrifugal slurry pump impeller of claim 3, wherein the end wall of one or more chambers has a diameter spanning a distance that substantially covers the width of the channel between adjacent pumping blades.

5. The centrifugal slurry pump impeller according to claim 1, wherein the wear-resistant component substantially fills the one or more cavities.

6. The centrifugal slurry pump impeller according to claim 1, wherein the wear-resistant component is cylindrical in shape.

7. The centrifugal slurry pump impeller according to claim 6, wherein the diameter of the wear-resistant component is greater than its height.

8. The centrifugal slurry pump impeller of claim 1, wherein the plug portion is located in the one or more cavities to cover the wear-resistant component located in the one or more cavities.

9. The centrifugal slurry pump impeller of claim 8, wherein the plug portion includes an outer surface that is substantially flush with or in the same plane as the outer surface of the rear cover.

10. A composite metal centrifugal slurry pump impeller comprising a rear cover having opposing inner and outer surfaces, the rear cover having an outer peripheral edge and a central axis, a plurality of pumping blades extending remotely from the inner surface of the rear cover, the pumping blades being arranged in a spaced-apart relationship, each pumping blade including opposing main side surfaces, a leading edge in a region of the central axis and a trailing edge in a region of the outer peripheral edge of the rear cover, a channel being provided between adjacent pumping blades, wherein one or more cavities are located in the rear cover, in a region of at least one of the channels, and wherein a wear-resistant component is at least partially incorporated within the one or more cavities, wherein the one or more cavities include sidewalls and endwalls, wherein the sidewalls include contact portions remote from the outer surface of the rear cover and wherein the contact portions are spaced apart from the surface of the inner surface of the rear cover.

11. The centrifugal slurry pump impeller of claim 10, wherein the one or more cavities include cylindrical sidewalls and circular endwalls of a certain length, and wherein, in use, the lengths of the sidewalls and the contact portions are oriented perpendicular to the flow direction through the channel and are located in a plane perpendicular to the axis of rotation of the pump impeller.

12. The centrifugal slurry pump impeller of claim 11, wherein the length of the sidewall and the contact portion substantially spans the passage of the adjacent pumping blade.

13. The centrifugal slurry pump impeller of claim 10, wherein the wear-resistant component substantially fills the one or more cavities.

14. The centrifugal slurry pump impeller of claim 10, wherein each channel comprises three chambers positioned at intervals along the length of each channel, starting from the leading edge of the pumping blade in the first two-thirds of the distance.

15. A composite metal centrifugal slurry pump impeller, the composite metal centrifugal slurry pump impeller comprising a rear cover having opposing inner and outer surfaces, the rear cover having an outer peripheral edge and a central axis, a plurality of pumping blades extending remotely from the inner surface of the rear cover, the pumping blades being arranged in a spaced-apart relationship, each pumping blade including opposing main sides, a leading edge in a region of the central axis and a trailing edge in a region of the outer peripheral edge of the rear cover, a channel being provided between adjacent pumping blades, wherein one or more cavities are formed in the inner surface of the rear cover, in a region of at least one of the channels, and wherein a wear-resistant component is at least partially incorporated within the one or more cavities, wherein the one or more cavities include a circular opening, cylindrical sidewalls and a circular endwall, and a line perpendicular to the central axis of the one or more cavities forms an angle with the surface of the inner surface of the rear cover.

16. The centrifugal slurry pump impeller of claim 15, wherein the one or more chambers are inclined from the plane of the rear cover, wherein when the slurry pump impeller is in use, the wear-resistant component incorporated in the one or more chambers is at an angle to the flow direction of the slurry.

17. The centrifugal slurry pump impeller of claim 15, wherein each channel includes an inner region and an outer region, the inner region beginning near the leading edge of the plurality of pumping blades and ending midway along each channel, the outer region beginning midway along each channel and ending near the outer peripheral edge, wherein the one or more cavities are substantially located in the inner region of each channel.

18. The centrifugal slurry pump impeller according to claim 15, wherein the wear-resistant component is located above the surface of the inner surface of the rear cover.

19. The centrifugal slurry pump impeller according to claim 15, wherein the slurry pump impeller is made of high-chromium white cast iron, and wherein the wear-resistant component is selected from tungsten carbide.

20. The centrifugal slurry pump impeller of claim 15, wherein one or more cavities are formed in the outer surface of the rear cover.

21. The centrifugal slurry pump impeller of claim 20, wherein one or more cavities in the region of the channel extend from the outside of the rear cover to the inside of the rear cover.

22. The centrifugal slurry pump impeller of claim 20, comprising a plug portion located at the circular opening of the one or more chambers, wherein the plug portion covers the wear-resistant component located within the one or more chambers.

23. The centrifugal slurry pump impeller of claim 22, wherein the plug portion includes an outer surface that is substantially flush with or in the same plane as the outer surface of the rear cover.

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