A high-efficiency anti-wear centrifugal sand delivery pump

Abstract

The application discloses a centrifugal sand and stone conveying pump with high wear resistance, and belongs to the technical field of fluid conveying, which comprises a volute, a front end cover, a rear end cover and an impeller, the impeller is arranged in the volute, the shaft surface of the impeller forms a smooth transition flow channel, a plurality of blades are arranged on the impeller along the self axis at intervals, the bone surface of the blade is composed of a plurality of continuous spline curves along the self extension direction, and there is at least one inflection point of the mounting angle of the blade along the arc length variation curve of the bone surface; the front end cover is arranged at the inlet of the volute, and a sealing structure is formed between the inner surface of the front end cover and the volute. In summary, the conveying pump effectively improves the pumping effect of large particle substances in the ore slurry, reduces the risk of blockage, and can better adapt to the high-efficiency conveying demand under complex working conditions through the unique flow channel of the impeller, the blade design and the sealing structure between the front end cover and the volute.

Description

Technical Field

[0001] This invention relates to the field of fluid transport technology, and in particular to a high-efficiency, wear-resistant centrifugal sand and gravel transport pump. Background Technology

[0002] In mining and mineral processing operations, large quantities of mixtures containing solid particles, such as slurry, mud, and waste residue, need to be transported to designated locations or discharged. Mining pumps, as key conveying equipment in these operations, play a vital role in ore mining, crushing, screening, and mineral processing.

[0003] Existing mining pumps typically employ straight or simple curved flow channel designs. These designs fail to adequately consider the flow patterns and mechanical properties of large particles in the slurry. Consequently, large particles easily generate flow resistance as they pass through the pump, leading to problems such as particle deposition, reduced flow rate, and blockage. Especially in slurry environments with high solids content and large particles, the throughput capacity of traditional pumps is significantly insufficient, failing to meet the demands for efficient transportation under complex operating conditions. Furthermore, the internal flow channels of the pump body are often not properly optimized for the flow characteristics of large particles, resulting in a substantial decrease in pump efficiency under large particle loads, and even damage to the pump body. Summary of the Invention

[0004] The purpose of this invention is to provide a high-efficiency, wear-resistant centrifugal sand and gravel conveying pump to solve the technical problems of poor pumping effect and easy clogging of large particles in slurry in existing mining pumps.

[0005] Based on the above concept, the technical solution adopted by this invention is as follows:

[0006] A high-efficiency, wear-resistant centrifugal sand and gravel conveying pump includes a volute, a front cover, a rear cover, and an impeller, specifically:

[0007] The impeller is disposed inside the volute, and the axial surface of the impeller forms a smoothly transitioned flow channel. Multiple blades are spaced apart on the impeller along its own axis. The rib surface of the blade is composed of multiple continuous spline curves along its own extension direction, and the mounting angle of the blade along the arc length variation curve of the rib surface has at least one inflection point.

[0008] The front end cover is disposed at the inlet of the volute, and a sealing structure is formed between the inner surface of the front end cover and the volute.

[0009] Preferably, the bone surface is composed of three continuous spline curves along its extension direction, namely a first spline curve, a second spline curve, and a third spline curve. The first spline curve is located on the side of the blade near the rear end cover, with an inlet installation angle of 38° to 40°, an outlet installation angle of 14° to 16°, and a wrap angle of 148° to 152°. The second spline curve is located in the middle of the blade, with an inlet installation angle of 25° to 27°, an outlet installation angle of 14° to 16°, and a wrap angle of 149° to 153°. The third spline curve is located on the side of the blade near the front end cover, with an inlet installation angle of 16° to 18°, an outlet installation angle of 14° to 16°, and a wrap angle of 150° to 154°.

[0010] Preferably, there are three blades, and the included angle between any two adjacent blades is 120 degrees.

[0011] Preferably, in the front and middle regions of the blade, the thickness of the blade is asymmetrically distributed on both sides of the bone surface.

[0012] Preferably, the blade includes a first thickness region, a second thickness region, and a third thickness region arranged sequentially from the leading edge to the trailing edge. In the first thickness region, the blade thickness gradually decreases along its own extension direction. In the second thickness region, the distance between the pressure surface of the blade and the bone surface gradually decreases, and the distance between the suction surface of the blade and the bone surface gradually increases. In the third thickness region, the pressure surface and suction surface of the blade are symmetrically distributed about the bone surface.

[0013] Preferably, the blade has a spatially twisted structure from the leading edge to the trailing edge, and the blade includes a first tilt angle region, a second tilt angle region, and a third tilt angle region arranged sequentially from the leading edge to the trailing edge. In the first tilt angle region, the tilt angle of the blade gradually decreases along the extension direction of the blade; in the second tilt angle region, the tilt angle of the blade is smaller than the minimum tilt angle in the first tilt angle region; and in the third tilt angle region, the tilt angle of the blade is smaller than the minimum tilt angle in the second tilt angle region.

[0014] Preferably, the leading edge of the blade has an elliptical cross-section, the major axis of which is aligned with the extension direction of the blade; the trailing edge of the blade has a cutting structure, the outline of which intersects with the outlet circumference of the impeller to form an arc-shaped transition area.

[0015] Preferably, the volute's vortex chamber cross-sectional shape is an axisymmetric structure, and the vortex chamber cross-sectional shape includes a converging section and an expanding section connected in sequence along the extension direction of the blade; the contour line of the converging section is a concave curve, the contour line of the expanding section is a convex curve, and the converging section and the expanding section smoothly transition at the maximum diameter of the vortex chamber cross-section.

[0016] Preferably, the inner surface of the front end cover is provided with a first concave ring structure at a position corresponding to the front end of the impeller. The first concave ring structure includes a first concave ring and a second concave ring with different widths. The first concave ring and the second concave ring are misaligned along the axial direction to form the sealing structure.

[0017] Preferably, the inner surface of the front end cover is provided with a second concave ring structure at a position corresponding to the impeller. The second concave ring structure includes two third concave rings of the same width. The two third concave rings are arranged opposite each other along the axial direction. The open ends of the two third concave rings are fastened together to form a cavity. A sealing filler is provided in the cavity to form the sealing structure.

[0018] The beneficial effects of this invention are:

[0019] This invention proposes a high-efficiency, wear-resistant centrifugal sand and gravel conveying pump. The impeller shaft surface forms a smoothly transitioning flow channel, preventing abrupt changes in cross-section or sharp turns in the fluid flow from inlet to outlet. This reduces the risk of large solid particles colliding and stagnating within the flow channel, ensuring smooth particle passage with the fluid. Multiple blades spaced apart on the impeller utilize a rib surface composed of multiple continuous spline curves. This continuous, smooth curve combination allows for a natural transition in the blade surface profile, eliminating localized flow separation zones caused by traditional straight-line spliced ​​blades, thereby reducing particle adhesion and accumulation on the blade surface. The blade installation angle is designed with at least one inflection point along the rib surface arc length variation curve, creating a variation pattern where the blade angle initially increases and then decreases, or initially decreases and then increases. This non-monotonic angle variation actively adjusts the force of the fluid on particles at different blade heights. Increasing the installation angle in the impeller inlet region enhances the capture capacity of solid particles, helps adjust the flow direction of large particles, and further improves pumping efficiency. The front cover is located at the inlet of the volute casing. The sealing structure formed between the front cover and the inner surface of the volute casing prevents slurry leakage, ensuring the normal operation of the pump. It also prevents external impurities from entering, ensuring unobstructed internal flow channels and preventing blockages caused by impurities. In summary, this transfer pump, through its unique impeller flow channel and blade design, as well as the sealing structure between the front cover and the volute casing, effectively improves the pumping efficiency for large particles in slurry, reduces the risk of blockage, and better adapts to the high-efficiency conveying needs under complex operating conditions. Attached Figure Description

[0020] Figure 1 This is a cross-sectional view of the high-efficiency wear-resistant centrifugal sand and gravel conveying pump provided in Embodiment 1 of the present invention;

[0021] Figure 2 This is a schematic diagram of the volute structure provided in Embodiment 1 of the present invention;

[0022] Figure 3 This is a schematic diagram of the first structure of the blade provided in Embodiment 1 of the present invention;

[0023] Figure 4 This is a schematic diagram of the second structure of the blade provided in Embodiment 1 of the present invention;

[0024] Figure 5 This is a cross-sectional view of the sealing structure provided in Embodiment 1 of the present invention;

[0025] Figure 6 This is a cross-sectional view of the sealing structure provided in Embodiment 2 of the present invention.

[0026] In the picture:

[0027] 1. Volute; 2. Front end cover; 3. Rear end cover; 4. Impeller; 5. Blade; 100. First concave ring structure; 101. First concave ring; 102. Second concave ring; 200. Second concave ring structure; 201. Third concave ring; 202. Sealing filler. Detailed Implementation

[0028] Embodiments of the present invention are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0029] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0031] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0032] Example 1

[0033] See Figures 1 to 5 The high-efficiency wear-resistant centrifugal sand and gravel conveying pump provided in this embodiment of the invention includes a volute 1, a front cover 2, a rear cover 3, and an impeller 4. The impeller 4 is disposed inside the volute 1, and its axial surface forms a smoothly transitioned flow channel. Multiple blades 5 are spaced along the impeller 4 around its own axis. The blade 5's rib surface is composed of multiple continuous spline curves along its extension direction, and the installation angle of the blade 5 along the arc length variation curve of the rib surface has at least one inflection point. The front cover 2 is disposed at the inlet of the volute 1, and a sealing structure is formed between the inner surface of the front cover 2 and the volute 1.

[0034] This invention proposes a high-efficiency, wear-resistant centrifugal sand and gravel conveying pump. The impeller 4's axial surface forms a smoothly transitioning flow channel, preventing abrupt changes in cross-section or sharp turns in the fluid flow from inlet to outlet. This reduces the risk of large solid particles colliding and stagnating within the flow channel, ensuring smooth particle passage with the fluid. Multiple blades 5 spaced apart on the impeller 4 utilize a rib surface composed of multiple continuous spline curves. The smooth, continuous curve combination allows for a natural transition in the blade 5's surface profile, eliminating localized flow separation zones caused by traditional straight-line spliced ​​blades, thereby reducing particle adhesion and accumulation on the blade 5's surface. The blade 5's installation angle is designed with at least one inflection point along the rib surface arc length variation curve, creating a variation in the blade 5's angle distribution that first increases and then decreases, or first decreases and then increases. This non-monotonic angle variation actively adjusts the fluid's force on particles at different blade heights. Increasing the installation angle in the impeller 4 inlet area enhances the capture capacity of solid particles, helps adjust the flow direction of large particles, and further improves pumping efficiency. The front cover 2 is located at the inlet of the volute 1. The sealing structure formed between the front cover 2 and the inner surface of the volute 1 prevents slurry leakage, ensuring the normal operation of the pump, and also prevents external impurities from entering, ensuring unobstructed internal flow channels and preventing blockages caused by impurities. In summary, this transfer pump, through the unique flow channel design of the impeller 4, the blade design 5, and the sealing structure between the front cover 2 and the volute 1, effectively improves the pumping effect on large particles in the slurry, reduces the risk of blockage, and can better adapt to the high-efficiency conveying requirements under complex working conditions.

[0035] The specific structure and working principle of this delivery pump will be described in detail below.

[0036] Impeller 4 is housed within volute 1, and its axial surface forms a smoothly transitioning flow channel. The axial surface refers to a specific plane containing the axis of rotation of impeller 4. On this plane containing the axis of rotation, the contour of the flow channel (typically formed by the hub, blades 5, and cover plate) through which the fluid (such as slurry) passes within impeller 4 is smooth and continuous, without abrupt turns or steps. This smooth transition is crucial for guiding smooth fluid flow, reducing flow separation and energy loss, and especially preventing large solid particles from getting stuck or depositing at flow channel corners. It ensures a natural and smooth flow path for the fluid from the impeller 4 inlet to the outlet.

[0037] Specifically, the width of the impeller 4 flow channel is minimum at the outlet, which is 42% of the suction diameter. The maximum curvature of the axial surface on the front cover 2 surface is located approximately 53% of the axial surface length behind the leading edge of the blade 5, and the product of the maximum curvature and the axial surface velocity at the rated flow rate is approximately 28.6 s⁻¹ (in this embodiment, the curvature of the front cover 2 surface is 4.4 m⁻¹, and the nearby axial surface velocity is 6.5 m / s). The maximum curvature of the axial surface on the rear cover 3 surface is located near the leading edge of the blade 5, approximately 48% of the axial surface length, and the product of the maximum curvature and the axial surface velocity at the rated flow rate is approximately 11.4 s⁻¹ (in this embodiment, the curvature of the rear cover 3 surface is 2.2 m⁻¹, and the nearby axial surface velocity is 5.2 m / s). Through the above settings, sufficient curvature is provided for the axial surface flow of the pump to change from the horizontal direction to the vertical direction, reducing secondary flow on the axial surface and enabling the pump to maintain high efficiency over a wide range of flow rate variations.

[0038] The impeller 4 has multiple blades 5 spaced apart along its axis. Specifically, there are three blades 5, with an included angle of 120 degrees between each adjacent pair. This arrangement makes the force exerted on the slurry more uniform when the impeller 4 rotates. The uniform spacing of the blades 5 in the circumferential direction allows them to work synergistically, enabling larger particles in the slurry to flow more orderly, reducing the possibility of collisions and accumulation between particles, thus further reducing the likelihood of blockage. Moreover, this uniformly distributed blade arrangement optimizes the force balance during impeller 4 rotation, making the pump more stable during operation, reducing equipment vibration caused by uneven force, extending equipment lifespan, ensuring continuous and efficient pumping of slurry, and improving operational reliability under complex conditions.

[0039] The skeletal surface of blade 5 is composed of multiple continuous spline curves along its own extension direction, and the mounting angle of blade 5 along the arc length variation curve of the skeletal surface has at least one inflection point. Specifically, the skeletal surface is composed of three continuous spline curves along its own extension direction, namely the first spline curve, the second spline curve, and the third spline curve. The first spline curve is located on the side of blade 5 near the rear end cover 3, with an inlet mounting angle of 38° to 40°, an outlet mounting angle of 14° to 16°, and a wrap angle of 148° to 152°. The second spline curve is located in the middle of blade 5, with an inlet mounting angle of 25° to 27°, an outlet mounting angle of 14° to 16°, and a wrap angle of 149° to 153°. The third spline curve is located on the side of blade 5 near the front end cover 2, with an inlet mounting angle of 16° to 18°, an outlet mounting angle of 14° to 16°, and a wrap angle of 150° to 154°. The above settings ensure that the installation angle of blade 5 is not monotonic and its concavity and convexity are not uniform. This differs from traditional high-efficiency pumps (where the first and second derivatives of the arc length-installation angle function of traditional blade 5 are on one side of the 0 value, and the first and second derivatives of the installation angle function of pumps both cross the 0 value). Blade 5 is convex at first and then concave, comprehensively balancing the throughput, efficiency, wear resistance, and cavitation resistance of the sand and gravel pump, thus providing efficient and stable performance in the conveying of high-concentration, large-diameter solid particles.

[0040] In the leading and middle regions of blade 5, the thickness of blade 5 is asymmetrically distributed on both sides of the slurry surface. In the leading region, this asymmetrical thickness distribution guides large particles in the incoming slurry to flow in a specific direction, optimizing the flow field at the inlet, allowing particles to enter the flow channel more smoothly, reducing impact and turbulence, lowering energy loss, and improving pump efficiency. In the middle region, the asymmetrical thickness of blade 5 further adjusts the trajectory of particles in the flow channel, preventing particle aggregation or collisions in this area and reducing the risk of blockage.

[0041] Specifically, the blade 5 includes a first thickness region, a second thickness region, and a third thickness region arranged sequentially from the leading edge to the trailing edge. In the first thickness region, the thickness of the blade 5 gradually decreases along its own extension direction. In the second thickness region, the distance between the pressure surface and the bone surface of the blade 5 gradually decreases, while the distance between the suction surface and the bone surface of the blade 5 gradually increases. In the third thickness region, the pressure surface and the suction surface of the blade 5 are symmetrically distributed about the bone surface.

[0042] In this embodiment, the front region of blade 5 is generally thicker. The first thickness region is from the leading edge of blade 5 to about 15% of the arc length of blade 5. Within the first thickness region, blade 5 gradually narrows, and then the distance between the pressure surface and the core surface of blade 5 decreases, while the thickness between the suction surface and the core surface of blade 5 increases. The second thickness region is about 40% of the arc length of blade 5, where the thickness of blade 5 is the smallest and the asymmetry is the greatest. Subsequently, the asymmetry gradually decreases, and the third thickness region is after 60% of the arc length of blade 5. Within the third thickness region, blade 5 reaches and maintains its maximum thickness, and the thickness asymmetry disappears. Unlike traditional transfer pumps where blade 5 has a uniform thickness or gradually increases from the inlet to the outlet, this design improves the load distribution of blade 5, reduces flow separation on the blade surface, and improves wear resistance and cavitation resistance. On the other hand, it also takes into account the efficiency and flow performance of the hydraulic pump.

[0043] The blade 5 has a spatially twisted structure from the leading edge to the trailing edge. The blade 5 includes a first tilt angle region, a second tilt angle region, and a third tilt angle region arranged sequentially from the leading edge to the trailing edge. In the first tilt angle region, the tilt angle of the blade 5 gradually decreases along the extension direction of the blade 5. In the second tilt angle region, the tilt angle of the blade 5 is smaller than the minimum tilt angle in the first tilt angle region. In the third tilt angle region, the tilt angle of the blade 5 is smaller than the minimum tilt angle in the second tilt angle region.

[0044] In this embodiment, the inclination angle of the first inclination region is 30° to 50°, the inclination angle of the second inclination region is 10° to 20°, and the inclination angle of the third inclination region is close to 0° to 5°, thereby suppressing local backflow at the outlet of the impeller 4 at different axial widths and circumferential angles, and ensuring that the slurry flows into the volute 1 uniformly.

[0045] The leading edge of blade 5 has an elliptical cross-section, with the major axis of the elliptical cross-section aligned with the extension direction of blade 5. This alignment creates a gently flowing, streamlined guide surface at the leading edge of blade 5. This structure guides large solid particles along their major axis when they contact the leading edge of blade 5, preventing instantaneous impact and rebound caused by right-angled edges. Furthermore, the continuous curvature of the ellipse disperses the impact stress on the particles, reducing the local wear rate at the leading edge and decreasing the probability of particles rebounding towards the center of the flow channel after collision, ensuring that the particle group enters the impeller 4 flow channel in an orderly manner.

[0046] The trailing edge of blade 5 has a cutting structure, and its contour line intersects with the outlet circumference of impeller 4 to form an arc-shaped transition area, eliminating the flow separation vortex generated by the traditional right-angle trailing edge. The contour line of the cutting structure intersects with the outlet circumference of impeller 4 to form an arc-shaped transition area. The arc transition allows the fluid to naturally separate tangentially at the outlet of blade 5, avoiding the stagnation and swirling of high-speed particles due to the sudden expansion of the trailing edge structure, and ensuring that solid particles are discharged from the flow channel in one go with high efficiency.

[0047] The volute 1 has an axisymmetric cross-sectional shape, consisting of a converging section and an expanding section connected sequentially along the extension direction of the blade 5. The converging section has an inwardly concave profile, which helps to gather and accelerate the fluid entering the volute 1, resulting in a more rational fluid velocity distribution and enhanced capacity to carry large particles. The expanding section has an outwardly convex profile, which allows the accelerated fluid to diffuse smoothly, reducing the flow velocity and effectively converting kinetic energy into pressure energy, thus increasing the pump's head. Furthermore, the converging and expanding sections smoothly transition at the maximum diameter of the volute cross-section, ensuring the continuity of fluid flow within the volute 1, reducing impacts and turbulence caused by abrupt changes in the flow path, further improving the pump's efficiency and stability in conveying slurries containing large particles, and reducing the risk of clogging.

[0048] Specifically, the vortex chamber of volute 1 has a pear-shaped cross-section, with eight sections at 45° angles to each other. The ratio of the area of ​​the end section to the area of ​​the beginning section of volute 1 is 2.2 (the end section of volute 1 is the cross-section where the liquid is about to leave volute 1 and enter the outlet pipe after completing energy conversion and flow path within volute 1; the beginning section of volute 1 is the cross-section where the liquid just enters volute 1), and the ratio of the pump suction port diameter to the discharge port diameter of volute 1 is 2.8. The growth rate of the cross-sectional area is initially small and then increases. This design balances the wear resistance of volute 1 with hydraulic efficiency over a wide flow variation range, while ensuring good tongue-bar passage performance.

[0049] The optimal discharge port angle of volute 1 to the ground is 80°. This design, on the one hand, distributes the fluid impact force and the overall weight of the pump casing on both sides of the pump centerline, thus optimizing the stress on the volute 1 base; on the other hand, it ensures that the time average value of the periodic stress on the pump bearing under conditions exceeding the rated flow is vertically upward along the pump centerline (collinear and opposite to the gravity of the impeller 4 on the pump bearing), which to some extent reduces the amplitude of the force on the pump shaft during operation, weakens the pump shaft vibration, and improves the working stability and service life of the pump.

[0050] The inner surface of the front cover 2 and the corresponding position of the front end of the impeller 4 are respectively provided with a first concave ring structure 100. The first concave ring structure 100 includes a first concave ring 101 and a second concave ring 102 with different widths. The first concave ring 101 and the second concave ring 102 are misaligned along the axial direction to form a sealing structure. The design of different widths and the axial misalignment form a multi-layered labyrinth-type sealing structure, which increases the path length and difficulty of slurry leakage. If the slurry is to leak, it must pass through a tortuous channel. During this process, the slurry pressure is gradually dispersed, reducing the possibility of leakage.

[0051] Example 2

[0052] Figure 6Embodiment 2 is shown, in which components identical or corresponding to those in Embodiment 1 are represented by the same reference numerals as in Embodiment 1. For simplicity, only the differences between Embodiment 2 and Embodiment 1 are described. The difference lies in that a second concave ring structure 200 is provided on the inner surface of the front cover 2 at a position corresponding to the impeller 4. The second concave ring structure 200 includes two third concave rings 201 of the same width, which are arranged axially opposite each other. The open ends of the two third concave rings 201 are engaged to form a cavity, and a sealing filler 202 is provided in the cavity to form a sealing structure. The cavity formed by the two engaging third concave rings 201 provides a stable installation space for the sealing filler 202, enabling the sealing filler 202 to better perform its sealing function. Furthermore, the sealing filler 202 filling the cavity can further enhance the sealing effect and effectively prevent slurry leakage. Since the slurry contains solid particles, this sealing structure can prevent particles from entering the critical parts of the pump, avoiding wear and damage caused by particle entry, and extending the service life of the pump. In addition, this sealing structure can maintain stable internal pump pressure, ensure efficient operation of the pump, improve pumping effect on slurry containing large particles, and adapt to complex mining conditions.

[0053] The above embodiments merely illustrate the basic principles and characteristics of the present invention. The present invention is not limited to the above embodiments. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-efficiency, wear-resistant centrifugal sand and gravel conveying pump, comprising a volute (1), a front end cover (2), a rear end cover (3), and an impeller (4), characterized in that: The impeller (4) is disposed inside the volute (1). The axial surface of the impeller (4) forms a smooth transition flow channel. Multiple blades (5) are spaced along the axis of the impeller (4). The rib surface of the blade (5) is composed of multiple continuous spline curves along its own extension direction. The installation angle of the blade (5) has at least one inflection point along the arc length variation curve of the rib surface. The front end cover (2) is disposed at the inlet of the volute (1), and a sealing structure is formed between the inner surface of the front end cover (2) and the volute (1); The bone surface is composed of three continuous spline curves along its extension direction, namely the first spline curve, the second spline curve, and the third spline curve. The first spline curve is located on the side of the blade (5) near the rear end cover (3), and the inlet installation angle of the first spline curve is 38° to 40°, the outlet installation angle is 14° to 16°, and the wrap angle is 148° to 152°. The second spline curve is located in the middle position of the blade (5), and the inlet installation angle of the second spline curve is 25° to 27°, the outlet installation angle is 14° to 16°, and the wrap angle is 149° to 153°. The third spline curve is located on the side of the blade (5) near the front end cover (2), and the inlet installation angle of the third spline curve is 16° to 18°, the outlet installation angle is 14° to 16°, and the wrap angle is 150° to 154°. In the front and middle regions of the blade (5), the thickness of the blade (5) is asymmetrically distributed on both sides of the bone surface.

2. The high-efficiency wear-resistant centrifugal sand and gravel conveying pump according to claim 1, characterized in that, There are 3 blades (5), and the included angle between any two adjacent blades (5) is 120 degrees.

3. The high-efficiency wear-resistant centrifugal sand and gravel conveying pump according to claim 1, characterized in that, The blade (5) includes a first thickness region, a second thickness region and a third thickness region arranged sequentially from the leading edge to the trailing edge. In the first thickness region, the thickness of the blade (5) gradually decreases along its own extension direction. In the second thickness region, the distance between the pressure surface of the blade (5) and the bone surface gradually decreases, and the distance between the suction surface of the blade (5) and the bone surface gradually increases. In the third thickness region, the pressure surface and suction surface of the blade (5) are symmetrically distributed about the bone surface.

4. The high-efficiency wear-resistant centrifugal sand and gravel conveying pump according to claim 1, characterized in that, The blade (5) has a spatially twisted structure from the leading edge to the trailing edge. The blade (5) includes a first tilt angle region, a second tilt angle region and a third tilt angle region arranged sequentially from the leading edge to the trailing edge. The tilt angle of the blade (5) in the first tilt angle region gradually decreases along the extension direction of the blade (5). The tilt angle of the blade (5) in the second tilt angle region is smaller than the minimum tilt angle in the first tilt angle region. The tilt angle of the blade (5) in the third tilt angle region is smaller than the minimum tilt angle in the second tilt angle region.

5. The high-efficiency wear-resistant centrifugal sand and gravel conveying pump according to claim 1, characterized in that, The leading edge of the blade (5) has an elliptical cross section, and the major axis of the elliptical cross section is aligned with the extension direction of the blade (5); the trailing edge of the blade (5) has a cutting structure, and the outline of the cutting structure intersects with the outlet circumference of the impeller (4) to form an arc-shaped transition area.

6. The high-efficiency wear-resistant centrifugal sand and gravel conveying pump according to claim 1, characterized in that, The vortex chamber cross-section of the volute (1) is an axisymmetric structure. The cross-section of the vortex chamber includes a converging section and an expanding section connected in sequence along the extension direction of the blade (5). The contour line of the converging section is a concave curve, and the contour line of the expanding section is a convex curve. The converging section and the expanding section smoothly transition at the maximum diameter of the vortex chamber cross-section.

7. The high-efficiency wear-resistant centrifugal sand and gravel conveying pump according to claim 1, characterized in that, The inner surface of the front cover (2) and the front end of the impeller (4) are respectively provided with a first concave ring structure (100). The first concave ring structure (100) includes a first concave ring (101) and a second concave ring (102) with different widths. The first concave ring (101) and the second concave ring (102) are misaligned along the axial direction to form the sealing structure.

8. The high-efficiency wear-resistant centrifugal sand and gravel conveying pump according to claim 1, characterized in that, The inner surface of the front cover (2) is provided with a second concave ring structure (200) at the position corresponding to the impeller (4). The second concave ring structure (200) includes two third concave rings (201) of the same width. The two third concave rings (201) are arranged opposite each other along the axial direction. The open ends of the two third concave rings (201) are fastened to each other to form a cavity. A sealing filler (202) is provided in the cavity to form the sealing structure.

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