Slurry pump impeller and manufacturing method thereof

Abstract

The present application relates to a slurry pump impeller and a manufacturing method thereof, belonging to the technical field of pump impellers. The slurry pump impeller includes a metal core and a plurality of blades, the metal core including a pair of first cover plates and a plurality of support plates; the pair of first cover plates are arranged relative to each other along a first direction; the support plates are located between the pair of first cover plates, and the support plates are fixed to the cover plates; the blades are provided with roots and ends along their lengths; wherein the plurality of blades are arranged in a circular array with the first direction as the axis; the roots are closer to the axes of the plurality of blades than the ends; the support plates pass through the blades, and the support plates support the blades; the support plates are arranged closer to the ends between the ends and the roots; and the plurality of blades correspond one-to-one to the plurality of support plates. The slurry pump impeller provided by the embodiment of the present application has a long service life.

Description

Technical Field

[0001] The present application relates to the technical field of pump impellers, and in particular to a slurry pump impeller and a manufacturing method thereof. Background Art

[0002] Phosphate chemical industry is an industrial system that uses phosphate rock as raw material and produces phosphorus-containing products through chemical processing. Phosphate chemical production will produce phosphogypsum tailings. In order to prevent phosphogypsum tailings from polluting the environment, the phosphogypsum tailings need to be treated. Phosphogypsum tailings are solid particles. In order to facilitate the transportation of phosphogypsum tailings, the solid phosphogypsum tailings are generally mixed with phosphogypsum slurry water to form a slurry, and the phosphogypsum tailings are wet-discharged through a conveying pump.

[0003] Centrifugal pumps transport phosphogypsum tailings by rotating the impeller in the pump casing at high speed, generating centrifugal force that propels the slurry at high speed. With the annual growth of the phosphate chemical industry, the height of phosphogypsum storage yards has also increased, and the distances between phosphogypsum tailings have also increased, requiring greater pump head capacity from phosphogypsum tailings pumps. To increase pump head capacity, the impeller diameter must be increased. However, the phosphogypsum slurry mixing water (some factories use more acidic tailings return water instead of phosphogypsum slurry mixing water for environmental reasons) mixed with phosphogypsum tailings is highly acidic and can corrode the impeller. Therefore, the impellers used in phosphogypsum tailings transportation are generally made of corrosion-resistant materials (such as ceramic). However, these materials are brittle and prone to cracking when subjected to high stress on the impeller edges. Therefore, the diameter of the impellers made of these materials cannot be too large.

[0004] To meet the increasing demands for higher pump lift during the transportation of phosphogypsum tailings, a high-strength metal skeleton can be installed inside the impeller to prevent blade breakage through the high strength of the metal skeleton. However, during operation, the root of the impeller blades is subjected to lower stress (lower centrifugal force and bending moment), but the number of cycles is extremely high. The metal skeleton at the root of the blades will quickly accumulate fatigue damage during the high-speed cyclic stress process, and then fail, resulting in a shorter overall blade life. Summary of the Invention

[0005] The purpose of this application is to address the above-mentioned problems and provide a slurry pump impeller with a longer service life, so as to improve the above-mentioned problems.

[0006] This application is achieved through the following technical solutions:

[0007] In the first aspect, the present application provides a slurry pump impeller, which includes a metal core and multiple blades, the metal core including a pair of first cover plates and multiple support plates; the pair of first cover plates are arranged opposite to each other along a first direction; the support plates are located between the pair of first cover plates, and the support plates are fixed to the cover plates; the blades are provided with roots and ends along their length directions; wherein the multiple blades are arranged in a circular array with the first direction as the axis; the roots are closer to the axes of the multiple blades than the ends; the support plates pass through the blades, and the support plates support the blades; the support plates are configured to be closer to the ends between the ends and the roots; the multiple blades correspond one-to-one to the multiple support plates.

[0008] In the technical solution of the embodiment of the present application, the stress cycle to which the slurry pump impeller is subjected during use is mainly caused by rotational periodic loads and vibration loads. The rotational periodic load is that each part of the impeller undergoes a complete stress cycle for each rotation of the impeller. The vibration load is a high-frequency alternating stress caused by water flow disturbance, mechanical resonance or external excitation. However, the effect of the rotational load on the root and end of the blade is: the number of cycles at the root and end is the same (once per rotation), but the stress amplitude increases from the root to the end; and the effect of the vibration load on the root and end of the blade is: since the constraint effect on the blade decreases from the root to the end, the root may be subjected to more frequent stress fluctuations due to the constraint effect. In summary, the stress (such as centrifugal force) borne by the end of the blade is large, but the number of cycles mainly comes from the rotation speed, and the frequency is low. The stress (such as centrifugal force) borne by the root of the blade is small, but the number of cycles comes from both the rotation speed and vibration, and the frequency is high.

[0009] In traditional designs, the root of the blade suffers from rapid fatigue failure of the metal skeleton due to cyclic stress concentration. This application changes the stress distribution by placing the support plate closer to the blade end. The metal support plate with a high fatigue limit supports the end, while the root is supported by the fatigue-resistant material of the blade itself, allowing the end to withstand more centrifugal force. The root is loaded by the support plate close to the end, reducing the local stress amplitude and subjecting the root to less stress. The fatigue-resistant properties of the blade's own material (such as ceramics, carbon fiber composites, etc.) allow the root to resist fatigue damage during high-speed cyclic stress, thereby extending the overall life of the blade.

[0010] The squirrel cage structure formed by the combination of the metal core and the cover plate and the support plate improves the overall rigidity of the impeller, especially suppressing the bending deformation of the blades caused by centrifugal force under high-speed rotation; for blades made of brittle materials (such as ceramics), the support of the metal core can reduce the stress concentration at the blade end, avoid brittle fracture, and allow the impeller diameter to be increased to meet high head requirements.

[0011] The blades are designed with a circular array, and the support plates correspond to the blades one by one. The evenly distributed support plates ensure that each blade is subjected to balanced force, reducing the risk of local overload and improving the smoothness of the impeller operation.

[0012] In some embodiments, a plurality of through holes are provided on the support plate and the first cover plate.

[0013] In the technical solution of the embodiment of the present application, a plurality of through holes are provided on the support plate and the first cover plate. The through holes can significantly reduce the weight of the support plate and the cover plate, thereby reducing the overall mass of the metal core bone and reducing the cyclic load of the centrifugal force on the root of the blade during high-speed rotation. After the mass is reduced, the bending moment and inertia force borne by the root of the blade are reduced, further delaying the accumulation of fatigue damage at the root and improving the service life of the slurry pump impeller provided by the present application. The through holes provide mechanical anchor points for the material of the blade during the manufacturing process. The slurry or adhesive penetrates into the holes to form a "locking structure", which improves the interface bonding strength and reduces the risk of separation between the metal core bone and the blade.

[0014] In some embodiments, the dimension from one end of the support plate close to the root to the other end close to the end is the length dimension of the support plate; the axes of the multiple blades pass through the axis of the first cover plate; the axis of one of a pair of first cover plates is connected to the driving member, and the axis of the other is provided with a liquid inlet; the length dimension of the side of the support plate close to the driving member is R1; the length dimension of the side of the support plate close to the liquid inlet is R2; and R1>R2.

[0015] In the technical solution of the embodiment of the present application, the first cover plate directly connected to the driving member in the metal core is more strongly restricted by the driving member, while the other first cover plate is a certain distance away from the driving member and is less controlled by the driving member. When R1>R2 is satisfied, the length dimension of the end of the support plate close to the driving member is greater than the dimension of the end of the support plate close to the liquid inlet. The dimension of the end of the support plate close to the liquid inlet is smaller, so that the weight of the portion of the metal core away from the driving member is smaller, thereby making the inertia of this portion smaller, which can adapt to the weaker control effect of the driving member, thereby preventing the portion of the metal core away from the driving member from vibrating relative to the driving member and affecting the normal rotation of the impeller; furthermore, after entering the impeller, the material will continue to flow into the impeller along the axial direction of the impeller under the action of the suction force of the negative pressure until it is blocked by the first cover plate connected to the driving member and the flow direction is changed. After contacting the first cover plate connected to the driving member, the material will continue to contact the blades, that is, the portion of the impeller close to the driving member will share this part of the impact force, and the length dimension of the end of the support plate close to the driving member is larger, which can provide a more reliable support effect for this portion of the impeller, thereby improving the service life of the impeller.

[0016] In some embodiments, an end of the support sheet close to the end portion is flush with the outer peripheral surface of the first cover plate.

[0017] In the technical solution of the embodiment of the present application, one end of the support plate close to the end is flush with the outer peripheral surface of the first cover plate, so that the size of the space in the center of the multiple support plates gradually decreases from the suction port to the driving member, and the shape of the support plate is adapted to the shape of the impeller, so that the size of the opening in the center of the impeller gradually decreases from the suction port to the driving member. This setting allows the material to enter the impeller until it is blocked and changed direction. During this process, the channel through which the material flows is gradually narrowed, allowing the water flow to concentrate and reduce energy loss.

[0018] In some embodiments, a pair of second cover plates are further included; the pair of second cover plates are arranged opposite to each other along the first direction; the first cover plate is located inside the second cover plate; the blade is located between the pair of second cover plates, and the blade is fixed to the second cover plates.

[0019] In the technical solution of the embodiments of this application, the second cover plate serves as an outer protective shield, encasing the first cover plate. This prevents the slurry formed by the mixture of phosphogypsum tailings and phosphogypsum slurry water (or tailings return water) from directly eroding the metal first cover plate, significantly reducing the risk of corrosion damage to the first cover plate. Furthermore, the blades are fixedly connected to the second cover plate, allowing some centrifugal force to be transmitted through the second cover plate to the axle to which the slurry pump blades are connected, reducing the stress amplitude at the root and thereby minimizing the risk of root damage.

[0020] In some embodiments, both ends of the support sheet extend into a pair of second cover plates and are respectively connected to a pair of first cover plates.

[0021] In the technical solution of the embodiment of the present application, the two ends of the support plate are respectively fixed to the first cover plate and the second cover plate to form a rigid connection that runs through the inner and outer layers, integrating the metal core bone and the second cover plate into a three-dimensional support frame, thereby improving the overall bending stiffness of the impeller and suppressing the radial deformation of the blades under high centrifugal force. The second cover plate and the blades wrap the entire metal core bone to prevent the slurry formed by the mixture of phosphogypsum tailings and phosphogypsum slurry water (or tailings return water) from contacting the metal core bone. The support plate passes through the second cover plate and is connected to the first cover plate to form a physical anchor point. Even if microcracks occur at the connection interface between the outer second cover plate and the blades, the internal support plate and the first cover plate can still provide mechanical support to prevent the cracks from spreading and improve the structural stability of the slurry pump impeller.

[0022] In some embodiments, the blade is made of carbon fiber composite material.

[0023] In the technical solution of the embodiment of the present application, traditional ceramic blades are difficult to meet high head requirements due to their high brittleness and limited impeller diameter. The material of the blades provided in the present application is carbon fiber composite material. The tensile strength of carbon fiber composite material (CFRP) is higher than that of steel. At the same time, it has excellent impact toughness and can withstand greater centrifugal force, allowing the slurry pump impeller diameter to be larger, thereby increasing the conveying head. The carbon fiber composite material has a low density, which can reduce the weight of the blades and reduce the load of centrifugal force on the metal core bone, thereby reducing the stress amplitude at the root and extending the fatigue life. The carbon fiber composite material also has extremely high corrosion resistance and can effectively prevent the blades from being corroded by phosphogypsum slurry water (or tailings return water).

[0024] In the second aspect, the present application provides a method for manufacturing a slurry pump impeller, which is used to manufacture the slurry pump impeller of the first aspect. The method for manufacturing the slurry pump impeller includes: step S100: connecting a first cover plate to one end of a plurality of support plates; step S200: installing a disposable inner mold between the plurality of support plates, and then connecting another first cover plate to the other end of the plurality of support plates to obtain a metal core bone; step S300: placing the metal core bone equipped with the disposable inner mold into a molding mold and injection molding to obtain a slurry pump impeller.

[0025] In the technical solution of the embodiment of the present application, in step S100, one end of a plurality of support sheets is connected to one of a pair of first cover plates, and the positions of the plurality of support sheets are fixed. In step S200, a disposable inner mold is installed between the plurality of support sheets from the end of the support sheet that is not connected to the cover plate, and then another first cover plate is connected to the other end of the plurality of support sheets to obtain a metal core bone. The inner mold accurately fills the gap between the support sheets to ensure that the non-metallic material (such as carbon fiber prepreg, corrosion-resistant engineering plastic) is evenly wrapped around the metal core bone during injection molding to avoid stress concentration caused by eccentricity or uneven wall thickness. Finally, in step S300, the metal core bone equipped with the disposable inner mold is placed into the molding mold and injection molded to obtain the slurry pump impeller. The other first cover plate is connected to the support sheet only after the disposable inner mold is installed between the support sheets, which simplifies the installation process of the disposable inner mold and makes it easier for the operator to adjust and determine the position of the disposable inner mold, reducing the risk of eccentricity of the metal core or uneven wall thickness. A disposable inner mold is used to complete the molding of the entire inner cavity of the slurry pump impeller, so that the wall of the inner cavity of the manufactured slurry pump impeller is flat and smooth, avoiding burrs and unevenness that may occur in the inner cavity manufactured by piecing together multiple inner molds. The manufacturing method of the slurry pump impeller provided in this application realizes the precision molding of high-lift, large-sized impellers by prefabricating the metal core + auxiliary injection molding of the inner mold, providing a manufacturing solution for slurry pump impellers with high efficiency, high reliability and low environmental load.

[0026] In some embodiments, step S400 is further included between step S200 and step S300: setting a transition layer on the molding surface of the metal core bone; wherein the molding surface is the surface of the metal core bone in contact with the molding liquid through the transition layer; the transition layer is composed of M layers of transition material, M≥3; the innermost N layers of transition material are the first material, the first material has elasticity, M>N≥1, and the first material is in close contact with the molding surface; the outermost K layer of transition material is the second material, the second material has adhesion, M>K≥1; the L layer of transition material located between the first material and the second material is the third material, the third material has low thermal conductivity, M>L≥1, N+K+L≤M.

[0027] In the technical solution of the embodiment of the present application, when the molding liquid is injected, the third material has a low thermal conductivity, which reduces the amount of thermal expansion caused by the metal core bone absorbing the heat of the molding liquid and causing its own temperature to rise. The first material deforms as the metal core bone expands. During the cooling stage of the molding liquid, the metal core bone shrinks in volume due to its own temperature drop, and the transition layer adheres to the molding surface of the metal core bone and maintains close contact. The first material deforms synchronously with the shrinkage of the metal core bone. At the same time, the second material has high fluidity and self-sealing properties. The second material can fill the gap between the molded body formed after the molding liquid is cooled and the third material, so that the transition layer can fill the gap left after the metal core bone shrinks and the gap that appears after the molding liquid cools and hardens, thereby reducing the probability of defects such as cavities or holes appearing between the molding liquid and the metal core bone during the cooling and hardening stage of the molding liquid.

[0028] In some embodiments, the first material is silicone rubber.

[0029] In the technical solution of the embodiment of the present application, the first material is silicone rubber, which has low elastic modulus characteristics and excellent flexibility. It can stably fit with the metal core bone and compensate for the thermal expansion of the metal core bone during the injection molding process through its own elastic deformation, thereby avoiding the formation of cavities between the metal core bone and the blades and the second cover plate due to the thermal expansion and contraction of the metal core bone, thereby improving the overall density of the slurry pump impeller.

[0030] In some embodiments, the second material is an epoxy resin-based nanocomposite material.

[0031] In the technical solution of the embodiments of this application, the second material is an epoxy resin-based nanocomposite material. This epoxy resin-based nanocomposite material is capable of infiltrating the surfaces of the blades and second cover plates facing the metal core and forming a dense structure after curing. Its high adhesion enhances the interfacial bonding between the metal core, blades, and second cover plates, reduces defects on the surfaces of the blades and second cover plates facing the metal core, and improves the stability of the connection between the metal core, blades, and second cover plates.

[0032] In some embodiments, the third material is a ceramic-based coating.

[0033] In the technical solution of the embodiment of the present application, the third material is a ceramic-based coating, which has low thermal conductivity (<30W / m·K) and high-temperature stability (>1000°C), and can effectively block the heat of the molding liquid from being conducted to the metal core bone, reducing its thermal expansion amplitude, and preventing the expansion of the metal core bone from exceeding the compensable amount of the first material, thereby reducing the risk of a cavity forming between the metal core bone and the blade and the second cover plate.

[0034] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 A schematic diagram of the overall structure of a slurry pump impeller provided in some embodiments of the present application;

[0037] Figure 2 A side view of a slurry pump impeller provided for some embodiments of the present application;

[0038] Figure 3 for Figure 2 Cross-sectional view at AA in the middle;

[0039] Figure 4 A schematic diagram of the structure of a metal core provided in some embodiments of the present application;

[0040] Figure 5 A flow chart of a method for manufacturing a slurry pump impeller provided in some embodiments of the present application;

[0041] Figure 6 A schematic cross-sectional view of a transition layer provided in some embodiments of the present application;

[0042] Figure 7 A flow chart of a method for manufacturing a slurry pump impeller provided in other embodiments of the present application;

[0043] Figure 8 Schematic diagram of the structure of the metal core provided in some other embodiments of the present application;

[0044] Icon: 1-metal core; 10-first cover plate; 11-support plate; 12-molding surface; 13-through hole; 2-blade; 20-root; 21-end; 3-second cover plate; 4-transition layer; 40-first material; 41-second material; 42-third material; X-first direction. DETAILED DESCRIPTION

[0045] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0046] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0047] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0048] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0049] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0050] The term "multiple" used in this application refers to more than two (including two). Similarly, "multiple groups" refers to more than two (including two) groups, and "multiple sheets" refers to more than two (including two) sheets.

[0051] According to some embodiments of the present application, optionally, Figure 3~Figure 4 As shown, the present application provides a slurry pump impeller, which includes a metal core bone 1 and multiple blades 2. The metal core bone 1 includes a pair of first cover plates 10 and multiple support plates 11; the pair of first cover plates 10 are arranged opposite to each other along a first direction X; the support plate 11 is located between the pair of first cover plates 10, and the support plate 11 is fixed to the cover plate; the blade 2 is provided with a root 20 and an end 21 along its length direction; wherein the multiple blades 2 are arranged in a circular array with the first direction X as the axis; the root 20 is closer to the axis of the multiple blades 2 than the end 21; the support plate 11 passes through the blade 2, and the support plate 11 supports the blade 2; the support plate 11 is configured to be closer to the end 21 between the end 21 and the root 20; the multiple blades 2 correspond one to one to the multiple support plates 11.

[0052] The material of the metal core 1 can be, but is not limited to, 2205 duplex stainless steel, CD4MCu duplex stainless steel, etc.

[0053] The material of the blade 2 can be, but is not limited to, ceramic, carbon fiber reinforced ceramic, carbon fiber composite material, etc.

[0054] One of the first cover plates 10 may be connected to the rotating shaft.

[0055] The diameter of the slurry pump impeller provided in this application is 700-900mm, the rotation speed n=980rpm, and the pump equipped with the slurry pump impeller provided in this application needs to withstand a pressure of 4.0MPa, a flow rate of 900-1300m³ / h, and a head of 70-90m.

[0056] The support sheet 11 and the cover plate can be welded, bonded or integrally formed; or the support sheet 11 can be integrally formed with one of the two cover plates and welded or bonded to the other, so that the end of the support sheet 11 not connected to the cover plate can first pass through the blade 2 and then be welded or bonded to the cover plate, reducing the difficulty of assembly.

[0057] The blades 2 cover the support sheet 11 to prevent the slurry formed by the mixture of phosphogypsum tailings and phosphogypsum slurry water (or tailings return water) from contacting the support sheet 11 and corroding the support sheet 11 .

[0058] The stress cycles experienced by a slurry pump impeller during use are primarily caused by rotational cyclical loads and vibrational loads. Rotational cyclical loads involve each impeller rotating once, with each part experiencing a complete stress cycle. Vibrational loads are high-frequency alternating stresses caused by water flow disturbances, mechanical resonance, or external excitation. However, the effects of rotational loads on the root 20 and tip 21 of blade 2 are as follows: the number of cycles at the root 20 and tip 21 is the same (once per revolution), but the stress amplitude increases from the root 20 to the tip 21. Conversely, the effects of vibrational loads on the root 20 and tip 21 of blade 2 are as follows: because the constraint effect on blade 2 decreases from the root 20 to the tip 21, the root 20 may experience more frequent stress fluctuations due to the constraint effect. In summary, the tip 21 of blade 2 experiences greater stress (e.g., centrifugal force), but the number of cycles is primarily driven by rotational speed, resulting in a lower frequency. The root 20 of blade 2 experiences less stress (e.g., centrifugal force), but the number of cycles is driven by both rotational speed and vibration, resulting in a higher frequency.

[0059] In traditional designs, the root 20 of the blade 2 suffers from rapid fatigue failure of the metal skeleton due to cyclic stress concentration. This application changes the stress distribution by placing the support sheet 11 close to the end 21 of the blade 2. The support sheet 11, which is made of metal with a high fatigue limit, supports the end 21, while the root 20 is supported by the fatigue-resistant material of the blade 2 itself, allowing the end 21 to withstand more centrifugal force. The root 20 shares the load with the support sheet 11 close to the end 21, reducing the local stress amplitude and subjecting the root 20 to less stress. The fatigue-resistant properties of the material of the blade 2 itself (such as ceramics, carbon fiber composite materials, etc.) allow the root 20 to resist fatigue damage during high-speed cyclic stress, thereby extending the overall life of the blade 2.

[0060] The squirrel-cage structure formed by the metal core 1 through the combination of the cover plate and the support plate 11 improves the overall rigidity of the impeller, especially suppressing the bending deformation of the blade 2 caused by centrifugal force under high-speed rotation; for blades 2 made of brittle materials (such as ceramics), the support of the metal core 1 can reduce the stress concentration at the end 21 of the blade 2, avoid brittle fracture, and allow the impeller diameter to be increased to meet high head requirements.

[0061] The blades 2 are designed in a circular array, and the support pieces 11 correspond to the blades 2 one by one. The evenly distributed support pieces 11 ensure that each blade 2 is subjected to balanced force, reducing the risk of local overload and improving the stability of the impeller operation.

[0062] Fatigue resistance refers to a material's ability to resist fatigue crack initiation, propagation, and eventual fracture under repeated cyclic loading. It reflects a material's overall tolerance to fatigue damage and is typically quantified by fatigue life (number of cycles) or crack growth rate.

[0063] The fatigue limit is the maximum alternating stress amplitude that a material can withstand under an infinite number of stress cycles without breaking. If the fatigue limit of a material is high, it is said to have a high fatigue limit.

[0064] According to some embodiments of the present application, optionally, Figure 4 As shown, a plurality of through holes 13 are provided on the support plate 11 and the first cover plate 10 .

[0065] The sizes of the plurality of through holes 13 may be the same; or, the sizes of the plurality of through holes 13 may be different.

[0066] When the sizes of multiple through holes 13 are different, the size of some through holes 13 near the connection between the support sheet 11 and the first cover plate 10 can be smaller than the size of other through holes 13. The stress on the connection between the support sheet 11 and the first cover plate 10 is greater. The smaller size of the through holes 13 in this area can reduce the impact of the setting of the through holes 13 on the strength of the connection between the support sheet 11 and the first cover plate 10, thereby reducing the risk of damage to the connection between the support sheet 11 and the first cover plate 10.

[0067] A plurality of through holes 13 are provided on the support plate 11 and the first cover plate 10. The through holes 13 can significantly reduce the weight of the support plate 11 and the cover plate, thereby reducing the overall mass of the metal core 1 and reducing the cyclic load of the centrifugal force on the root 20 of the blade 2 during high-speed rotation. After the mass is reduced, the bending moment and inertial force borne by the root 20 of the blade 2 are reduced, further delaying the accumulation of fatigue damage at the root 20 and improving the service life of the slurry pump impeller provided by this application. The through holes 13 provide mechanical anchor points for the material of the blade 2 during the manufacturing process. The slurry or adhesive penetrates into the holes to form a "locking structure", which improves the interface bonding strength and reduces the risk of separation between the metal core 1 and the blade 2.

[0068] According to some embodiments of the present application, optionally, Figure 8 As shown, the dimension from one end of the support sheet 11 close to the root 20 to the end close to the end 21 is the length dimension of the support sheet 11; the axis of the plurality of blades 2 passes through the axis of the first cover plate 10; the axis of one of the pair of first cover plates 10 is connected to the driving member, and the axis of the other is provided with a liquid inlet; the length dimension of the side of the support sheet 11 close to the driving member is R1; the length dimension of the side of the support sheet 11 close to the liquid inlet is R2; and R1>R2 is satisfied.

[0069] The first cover plate 10 directly connected to the driving member in the metal core 1 is more strongly restricted by the driving member, while the other first cover plate 10 is at a certain distance from the driving member and is less controlled by the driving member. When R1>R2 is satisfied, the length of the end of the support plate 11 close to the driving member is greater than the length of the end of the support plate 11 close to the liquid inlet, and the length of the end of the support plate 11 close to the liquid inlet is smaller, so that the weight of the part of the metal core 1 away from the driving member is smaller, thereby making the inertia of this part smaller, which can adapt to the weaker control effect of the driving member, thereby avoiding the metal core 1 The part away from the driving member vibrates relative to the driving member, affecting the normal rotation of the impeller; furthermore, after the material enters the impeller, it will continue to flow into the impeller along the axial direction of the impeller under the action of the suction force of the negative pressure until it is blocked by the first cover plate 10 connected to the driving member and the flow direction is changed. After the material contacts the first cover plate 10 connected to the driving member, it will continue to contact the blades 2, that is, the part of the impeller close to the driving member will share this part of the impact force, and the length of the support sheet 11 at the end close to the driving member is larger, which can provide a more reliable support effect for this part of the impeller, thereby improving the service life of the impeller.

[0070] According to some embodiments of the present application, optionally, Figure 8 As shown, one end of the support sheet 11 close to the end portion 21 is flush with the outer circumferential surface of the first cover plate 10 .

[0071] One end of the support sheet 11 close to the end portion 21 is flush with the outer peripheral surface of the first cover plate 10, so that the size of the space in the center of the multiple support sheets 11 gradually decreases from the suction port to the driving member, and the shape of the support sheet 11 is adapted to the shape of the impeller, so that the size of the opening in the center of the impeller gradually decreases from the suction port to the driving member. This arrangement allows the material to enter the impeller until it is blocked and changed direction. During this process, the channel through which the material flows is gradually narrowed, allowing the water flow to be concentrated and reduce energy loss.

[0072] According to some embodiments of the present application, optionally, Figure 1~Figure 2 As shown, it also includes a pair of second cover plates 3; the pair of second cover plates 3 are arranged opposite to each other along the first direction X; the first cover plate 10 is located inside the second cover plates 3; the blade 2 is located between the pair of second cover plates 3, and the blade 2 is fixed to the second cover plates 3.

[0073] The material of the second cover plate 3 may be the same as that of the blade 2 ; or, the material of the second cover plate 3 may be different from that of the blade 2 .

[0074] On the one hand, the second cover plate 3 acts as an outer protective shield, enclosing the first cover plate 10. This prevents the slurry formed by the mixture of phosphogypsum tailings and phosphogypsum slurry water (or tailings return water) from directly eroding the metal first cover plate 10, significantly reducing the risk of corrosion damage to the first cover plate 10. On the other hand, the blades 2 are fixed to the second cover plate 3, allowing some centrifugal force to be transmitted through the second cover plate 3 to the axle to which the slurry pump blades are connected, reducing the stress amplitude at the root 20 and thereby reducing the risk of damage to the root 20.

[0075] According to some embodiments of the present application, optionally, both ends of the support sheet 11 extend into a pair of second cover plates 3 and are respectively connected to a pair of first cover plates 10 .

[0076] The two ends of the support plate 11 are respectively fixed to the first cover plate 10 and the second cover plate 3, forming a rigid connection that runs through the inner and outer layers. This integrates the metal core 1 and the second cover plate 3 into a three-dimensional support frame, improving the overall bending stiffness of the impeller and suppressing radial deformation of the blades 2 under high centrifugal forces. The second cover plate 3 and the blades 2 enclose the entire metal core 1, preventing the slurry formed by the mixture of phosphogypsum tailings and phosphogypsum slurry water (or tailings return water) from coming into contact with the metal core 1. The support plate 11 passes through the second cover plate 3 and connects to the first cover plate 10, forming a physical anchor point. Even if microcracks occur at the connection interface between the outer second cover plate 3 and the blades 2, the internal support plate 11 and the first cover plate 10 can still provide mechanical support to prevent the cracks from spreading and improve the structural stability of the slurry pump impeller.

[0077] According to some embodiments of the present application, optionally, the blade 2 is made of carbon fiber composite material.

[0078] The material of the blade 2 can be, but is not limited to, a carbon fiber / epoxy resin composite material, a carbon fiber / polyimide resin composite material, a carbon fiber / phenolic resin composite material, and the like.

[0079] Traditional ceramic blades 2 are difficult to meet high lift requirements due to their high brittleness and limited impeller diameter. The material of the blades 2 provided in this application is carbon fiber composite material. The tensile strength of carbon fiber composite material (CFRP) is higher than that of steel. At the same time, it has excellent impact toughness and can withstand greater centrifugal force, allowing the slurry pump impeller to have a larger diameter, thereby increasing the conveying lift. The carbon fiber composite material has a low density, which can reduce the weight of the blade 2 and reduce the load of centrifugal force on the metal core 1, thereby reducing the stress amplitude of the root 20 and extending the fatigue life. The carbon fiber composite material also has extremely high corrosion resistance and can effectively prevent the blade 2 from being corroded by phosphogypsum slurry water (or tailings return water).

[0080] According to some embodiments of the present application, optionally, Figure 5As shown, the present application provides a method for manufacturing a slurry pump impeller, which is used to manufacture the above-mentioned slurry pump impeller. The method for manufacturing a slurry pump impeller includes: step S100: connecting a first cover plate 10 to one end of a plurality of support plates 11; step S200: installing a disposable inner mold between the plurality of support plates 11, and then connecting another first cover plate 10 to the other end of the plurality of support plates 11 to obtain a metal core bone 1; step S300: placing the metal core bone 1 equipped with the disposable inner mold into a molding mold and injection molding to obtain a slurry pump impeller.

[0081] A disposable inner mold is a temporary support structure used to form an internal cavity during the injection molding process. It is used to produce parts with complex shapes. Disposable inner molds may be made of biodegradable materials, foam plastics, gypsum, salt, etc. to facilitate their disposal after use.

[0082] The support plate 11 can be connected to the first cover plate 10 by welding.

[0083] Injection molding, also known as injection molding, is a molding process that combines injection and molding. At a certain temperature, a screw stirs completely molten material (the molding liquid) and injects it into the mold cavity (the molding cavity of the mold) at high pressure. After cooling and solidification, the molded part is obtained. This method is suitable for the mass production of complex-shaped parts and is one of the most important processing methods. The injection molding process can be roughly divided into six stages: mold closing, injection, pressure holding, cooling, mold opening, and product removal.

[0084] The molten molding liquid injected into the molding mold has a certain temperature, namely the injection temperature.

[0085] In step S100, one end of the multiple support sheets 11 is connected to one of a pair of first cover plates 10, and the positions of the multiple support sheets 11 are fixed. In step S200, a disposable inner mold is installed between the multiple support sheets 11 from the end of the support sheet 11 that is not connected to the cover plate, and then another first cover plate 10 is connected to the other end of the multiple support sheets 11 to obtain a metal core bone 1. The inner mold accurately fills the gap between the support sheets 11 to ensure that the non-metallic material (such as carbon fiber prepreg, corrosion-resistant engineering plastic) is evenly wrapped around the metal core bone 1 during injection molding to avoid stress concentration caused by eccentricity or uneven wall thickness. Finally, in step S300, the metal core bone 1 equipped with the disposable inner mold is placed into the molding mold and injection molded to obtain the slurry pump impeller. The other first cover plate 10 is connected to the support sheet 11 only after the disposable inner mold is installed between the support sheets 11, which simplifies the installation process of the disposable inner mold and makes it easier for the operator to adjust and determine the position of the disposable inner mold, reducing the risk of eccentricity or uneven wall thickness of the metal core 1. A disposable inner mold is used to complete the molding of the entire inner cavity of the slurry pump impeller, so that the wall of the inner cavity of the manufactured slurry pump impeller is flat and smooth, avoiding burrs and unevenness that may occur in the inner cavity manufactured by piecing together multiple inner molds. The manufacturing method of the slurry pump impeller provided in this application realizes the precision molding of high-lift, large-sized impellers by prefabricating the metal core 1 + auxiliary injection molding of the inner mold, providing a manufacturing solution for slurry pump impellers with high efficiency, high reliability and low environmental load.

[0086] According to some embodiments of the present application, optionally, Figure 6-Figure 7 As shown, step S400 is further included between step S200 and step S300: a transition layer 4 is provided on the molding surface 12 of the metal core 1; wherein the molding surface 12 is the surface of the metal core 1 in contact with the molding liquid through the transition layer 4; the transition layer 4 is composed of M layers of transition material, M≥3; the innermost N layers of transition material are the first material 40, the first material 40 has elasticity, M>N≥1, and the first material 40 is in close contact with the molding surface 12; the outermost K layer of transition material is the second material 41, the second material 41 has adhesion, M>K≥1; the L layer of transition material located between the first material 40 and the second material 41 is the third material 42, the third material 42 has low thermal conductivity, M>L≥1, N+K+L≤M.

[0087] The molten molding liquid injected into the molding mold has a certain temperature, namely the injection temperature.

[0088] The molding temperature range of carbon fiber composites varies depending on the matrix material (resin or high-temperature matrix) and process. Carbon fiber casting has a wide range of temperatures, including: medium- and low-temperature resin-based carbon fibers (120°C to 230°C), high-temperature thermoplastic carbon fibers (300°C to 400°C), and ultra-high-temperature carbon / carbon composites (>800°C). In actual processing, the appropriate transition layer material can be selected based on the actual processing temperature.

[0089] When the molding liquid is injected, the third material 42 has a low thermal conductivity, which reduces the amount of thermal expansion caused by the metal core bone 1 absorbing the heat of the molding liquid and causing its own temperature to rise. The first material 40 deforms with the expansion of the metal core bone 1. During the cooling stage of the molding liquid, the metal core bone 1 shrinks in volume due to its own temperature drop. The transition layer 4 adheres to the molding surface 12 of the metal core bone 1 and maintains close contact. The first material 40 deforms synchronously with the shrinkage of the metal core bone 1. At the same time, the second material 41 has high fluidity and self-sealing properties. The second material 41 can fill the gap between the molded body formed after the molding liquid is cooled and the third material 42, so that the transition layer 4 can fill the gap left after the metal core bone 1 shrinks and the gap formed after the molding liquid is cooled and hardened, thereby reducing the probability of defects such as cavities or holes between the molding liquid and the metal core bone 1 during the cooling and hardening stage of the molding liquid.

[0090] According to some embodiments of the present application, optionally, the first material 40 is silicone rubber.

[0091] Silicone rubber's temperature resistance range (-60°C to 250°C) covers most injection molding process requirements. During high-temperature injection molding, silicone rubber will not undergo thermal decomposition or permanent deformation, ensuring the integrity of the elastic layer.

[0092] The first material 40 is silicone rubber, which has low elastic modulus characteristics and excellent flexibility. It can stably fit with the metal core bone 1 and compensate for the thermal expansion of the metal core bone 1 during the injection molding process through its own elastic deformation, thereby avoiding the formation of cavities between the metal core bone 1 and the blades 2 and the second cover plate 3 due to the thermal expansion and contraction of the metal core bone 1, thereby improving the overall density of the slurry pump impeller.

[0093] According to some embodiments of the present application, optionally, the second material 41 is an epoxy resin-based nanocomposite material.

[0094] Epoxy resin-based nanocomposites are epoxy resins with added nanoparticles (such as carbon nanotubes and graphene) and have good fluidity.

[0095] The second material 41 is an epoxy resin-based nanocomposite material. This epoxy resin-based nanocomposite material is capable of infiltrating the surfaces of the blades 2 and second cover plates 3 facing the metal core 1 and forming a dense structure after curing. Its high adhesion enhances the interfacial bonding between the metal core 1 and the blades 2 and second cover plates 3, reduces defects on the surfaces of the blades 2 and second cover plates 3 facing the metal core 1, improves the connection stability between the metal core 1, blades 2, and second cover plates 3, and enhances the internal density of the slurry pump impeller.

[0096] According to some embodiments of the present application, optionally, the third material 42 is a ceramic-based coating.

[0097] The ceramic-based coating may be, but is not limited to, aluminum oxide, boron nitride, and the like.

[0098] The third material 42 is a ceramic-based coating, which has low thermal conductivity (<30 W / m·K) and high-temperature stability (>1000°C). It can effectively block the heat of the molding liquid from being transferred to the metal core 1, reducing its thermal expansion amplitude, and preventing the expansion of the metal core 1 from exceeding the compensable amount of the first material 40, thereby reducing the risk of a cavity forming between the metal core 1 and the blade 2 and the second cover plate 3.

[0099] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be substituted with equivalents without departing from the scope of the present application. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions within the scope of the claims.

Claims

1. A slurry pump impeller, characterized in that: include: A metal core bone, comprising a pair of first cover plates and a plurality of support plates; A pair of the first cover plates are arranged opposite to each other along a first direction; The support sheet is located between a pair of the first cover plates, and the support sheet is fixedly connected to the cover plates; a plurality of blades, each blade having a root and an end along its length; Wherein, the plurality of blades are arranged in a circular array with the first direction as the axis; The root portion is closer to the axes of the plurality of blades than the end portion; The supporting sheet passes through the blade, and the supporting sheet supports the blade; The supporting piece is configured to be closer to the end portion between the end portion and the root portion; The plurality of blades corresponds one to one to the plurality of support pieces.

2. A slurry pump impeller according to claim 1, characterized in that: A plurality of through holes are provided on the support plate and the first cover plate.

3. A slurry pump impeller according to claim 1, characterized in that: The dimension from one end of the support sheet close to the root to the other end close to the end is the length dimension of the support sheet; The axes of the plurality of blades pass through the axis of the first cover plate; The axis of one of the pair of first cover plates is connected to the driving member, and the axis of the other cover plate is provided with a liquid inlet; The length of the side of the support plate close to the driving member is R1; The length of the side of the support sheet close to the liquid inlet is R2; Satisfies, R1>R2.

4. A slurry pump impeller according to claim 3, characterized in that: One end of the support sheet close to the end portion is flush with the outer peripheral surface of the first cover plate.

5. The slurry pump impeller according to claim 1, characterized in that: Also included is a pair of second cover plates; A pair of the second cover plates are arranged opposite to each other along the first direction; The first cover plate is located inside the second cover plate; The blade is located between a pair of the second cover plates, and the blade is fixed to the second cover plates.

6. A slurry pump impeller according to claim 5, characterized in that: Two ends of the support plate extend into a pair of second cover plates and are respectively connected to a pair of first cover plates.

7. A slurry pump impeller according to claim 1, characterized in that: The material of the blade is carbon fiber composite material.

8. A method for manufacturing a slurry pump impeller, for manufacturing the slurry pump impeller according to any one of claims 1 to 7, characterized in that: include: Step S100: connecting one of the first cover plates to one end of the plurality of support plates; Step S200: inserting a disposable inner mold between the plurality of support sheets, and then connecting another first cover plate to the other end of the plurality of support sheets to obtain the metal core; Step S300: placing the metal core with the disposable inner mold into a forming mold and performing injection molding to obtain a slurry pump impeller.

9. The method for manufacturing a slurry pump impeller according to claim 8, characterized in that: Between step S200 and step S300, step S400 is further included: providing a transition layer on the forming surface of the metal core; Wherein, the molding surface is the surface of the metal core bone in contact with the molding liquid through the transition layer; The transition layer is composed of M layers of transition materials, M ≥ 3; The innermost N layers of transition material are the first material, the first material has elasticity, M>N≥1, and the first material is in close contact with the forming surface; The transition material of the outermost K layer is the second material, and the second material has adhesion, M>K≥1; The transition material in the L layer between the first material and the second material is a third material. The third material has low thermal conductivity, M>L≥1, N+K+L≤M.

10. The method for manufacturing a slurry pump impeller according to claim 9, characterized in that: The first material is silicone rubber.

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