Ceramic pump with silicon carbide flow parts

Abstract

The utility model belongs to ceramic pump technical field discloses a kind of ceramic pumps with silicon carbide flow parts, including pump body shell, transmission shaft is rotationally arranged in the inside of pump body shell, impeller is coaxially fixedly assembled on transmission shaft, the one end of pump body shell is fixedly connected with sheath, and impeller is rotationally arranged in the cavity of sheath, rear baffle is sealingly equipped between impeller and the inner wall of pump body shell, the one end of sheath away from pump body shell is fixedly covered with pump cover, and front baffle is sealingly equipped between the inside of impeller and pump cover;The utility model whole simple structure can enhance the combination stability of silicon carbide flow parts and matrix, improve the impact resistance and wear and corrosion resistance synergic performance of silicon carbide material, optimize the flow resistance characteristics of silicon carbide flow channel, improve use effect.

Description

Technical Field

[0001] This utility model belongs to the field of ceramic pump technology, specifically, it relates to a ceramic pump with silicon carbide flow elements. Background Technology

[0002] In industrial sectors such as chemical, mining, metallurgy, power plant desulfurization, and environmental solid waste treatment, it is often necessary to transport media containing high-hardness solid particles and highly corrosive media (such as acid and alkali solutions, mineral slurries, desulfurization slurries, and sludge). These operating conditions place stringent requirements on the pump's wear resistance, corrosion resistance, and erosion resistance. Traditional metal pump bodies and flow parts, due to their low hardness and poor chemical stability, are prone to wear, corrosion, and leakage under the long-term action of harsh media. This results in short equipment lifespan, high maintenance frequency, and significantly increased operating costs, making it difficult to meet the high-efficiency and stable demands of industrial production.

[0003] Currently, while traditional ceramic materials (alumina ceramics, silicon nitride ceramics, etc.) outperform metals in hardness and corrosion resistance, they suffer from drawbacks such as high brittleness, poor impact resistance, and high manufacturing costs. In recent years, silicon carbide ceramics, with their high hardness (Mohs hardness above 9.0), excellent resistance to strong acid and alkali corrosion, and good chemical inertness, have become the preferred material for flow-through components. Ceramic pumps based on silicon carbide flow-through components are gradually becoming a hot research topic in the industry.

[0004] Chinese patent application CN2023209198898 discloses a silicon carbide ceramic pump with anti-detachment, wear-resistant, and corrosion-resistant properties. The pump body, impeller, and pump cover are made of either reaction-bonded silicon carbide or self-propagating high-temperature synthesized silicon carbide. The pump body coating and pump cover coating are made of either reaction-bonded silicon carbide or oxide-bonded silicon carbide. This application's embodiment, by using reaction-bonded silicon carbide or self-propagating high-temperature synthesized silicon carbide as the silicon carbide ceramic material, effectively solves the technical problem of low fracture toughness and brittle fracture in existing silicon carbide ceramic materials, which affects the reliability and safety of silicon carbide ceramic pumps. This improves the corrosion resistance and high-temperature resistance of the silicon carbide ceramic pump, extends its service life, and reduces maintenance costs.

[0005] However, although the reaction sintering and self-propagating high-temperature synthesized silicon carbide used in this patent improves fracture toughness, its anti-fracture ability under the impact of high-hardness particle media is still insufficient. Moreover, its coating only focuses on the interface connection problem and does not strengthen the wear-prone areas of the flow parts. The coating thickness (0.1-0.5mm) is relatively thin, and the coating is prone to wear failure under long-term scouring, which in turn leads to substrate corrosion. In addition, the patent only mentions that silicon carbide ceramic material is set on the outer surface of the impeller, suggesting that it adopts an integral ceramic molding or simple coating structure. During long-term operation, stress concentration is easily generated due to vibration, which may cause the impeller and shaft connection to loosen or even crack. Utility Model Content

[0006] The main technical problem to be solved by this utility model is to provide a ceramic pump with silicon carbide flow elements that has a simple overall structure, enhances the bonding stability between silicon carbide flow elements and the substrate, improves the synergistic performance of silicon carbide material in terms of impact resistance, wear resistance and corrosion resistance, optimizes the flow resistance characteristics of silicon carbide flow channels, avoids silicon carbide components from falling off, cracking or wearing out, and improves the performance of the pump.

[0007] To solve the above-mentioned technical problems, this utility model provides the following technical solution: A ceramic pump with silicon carbide flow elements includes a pump body shell, a drive shaft rotatably passing through the pump body shell, an impeller coaxially fixedly mounted on the drive shaft, a sheath fixedly connected to one end of the pump body shell, and the impeller rotatably disposed within the cavity of the sheath, a rear guard plate sealingly installed between the impeller and the inner wall of the pump body shell, a pump cover fixedly covering the end of the sheath away from the pump body shell, and a front guard plate sealingly installed between the impeller and the inner side of the pump cover; Both the front and rear protective plates are made of silicon carbide powder as raw material and are integrally formed by a three-stage gradient sintering process. The impeller includes an impeller body with a metal skeleton inside. Impeller cover plates are bonded to both sides of the impeller body. The impeller body and impeller cover plates are also made of silicon carbide powder as raw material and are integrally formed by a three-stage gradient sintering process.

[0008] The following are further optimizations of the above technical solution by this utility model: The impeller body is composed of two symmetrically designed, connected parts.

[0009] Further optimization: The two parts are made of silicon carbide powder as raw material and are integrally formed by a three-stage gradient sintering process, and the mating surfaces of the two parts are bonded and fixed.

[0010] Further optimization: The outer surface of the split body has a ring array of multiple protrusions, and multiple circular holes are opened on the outer surface of the split body near the positions of the multiple protrusions. The circular holes correspond one-to-one with the protrusions and are evenly distributed along the circumference of the split body.

[0011] Further optimization: The outer circular surface of the split body is evenly spaced with multiple blades, each blade extending outward at a certain angle to the radial direction of the split body, and adjacent blades are symmetrically arranged at equal angles, with the center angles of adjacent blades being consistent.

[0012] Further optimization: The metal frame includes a frame body, and positioning holes are provided at positions on the surface of the frame body that correspond one-to-one with the protrusions of the impeller body.

[0013] Further optimization: The outer dimensions of the protrusion are adapted to the inner dimensions of the positioning hole, and the two adopt a transition fit to achieve a tight fit.

[0014] Further optimization: The metal frame has a positioning post integrally formed at the position where it corresponds to the circular hole of the split body along both end faces. The outer diameter of the positioning post is adapted to the diameter of the circular hole, and the two adopt a transition fit to achieve precise positioning.

[0015] Further optimization: Impeller cover plates are bonded to both end faces of the impeller body. The impeller cover plates are made of silicon carbide powder as raw material and are integrally formed by a three-stage gradient sintering process, which is consistent with the impeller body in terms of material and process. On the side surface of each of the two impeller cover plates opposite to the impeller body, there are multiple first blades arranged in a ring array near the outer edge, and each first blade extends outward along the radial direction of the impeller cover plate.

[0016] Further optimization: The sheath includes a support shell, and a bushing is bonded to the inner wall of the support shell. The bushing is made of silicon carbide powder as raw material and is integrally formed by a three-stage gradient sintering process.

[0017] This utility model adopts the above-mentioned technical solution, with ingenious conception and reasonable structure. Through the coordinated design of structural innovation, material optimization and process upgrade, it solves the technical pain points of traditional metal pump flow parts being prone to wear and corrosion, conventional ceramic pumps having poor impact resistance and unstable component connections.

[0018] The core flow components (front guard plate, rear guard plate, impeller body, impeller cover plate, and bushing) are all made of silicon carbide powder and integrally formed through a three-stage gradient sintering process. The final parts have high density and a Mohs hardness of over 9.0, and have extremely strong wear resistance and acid and alkali corrosion resistance. They can resist the scouring of high-hardness particulate media and the erosion of strong corrosive media. Compared with traditional metal pumps (high chromium alloy material), the service life is extended by 3-5 times, which greatly reduces the frequency of equipment replacement under harsh working conditions. Silicon carbide is chemically inert and does not react with media such as acid and alkali solutions, slurries, and desulfurization slurries. This avoids the media contamination and equipment leakage problems caused by corrosion of traditional metal pumps, improves the safety and purity of the conveying process, and is suitable for the stringent use requirements of chemical, mining, power desulfurization and other fields.

[0019] The impeller body adopts a composite structure of metal skeleton + dual silicon carbide split. The circumferential positioning of the protrusion block and the positioning hole and the axial positioning of the positioning column and the round hole form a double precise constraint. With the chemical bonding effect of silane modified epoxy special adhesive, the metal skeleton and silicon carbide split are stably connected, effectively dispersing the torque and media impact load when the impeller rotates, and avoiding the silicon carbide parts from cracking and falling off due to stress concentration. The impeller body, impeller cover, and the support shell and bushing of the sheath are all fixed with the same special adhesive, which is resistant to high temperature and media erosion. Combined with the synergistic constraint of the positioning structure, it ensures that each component maintains the integrity of the structure under conditions such as high-speed rotation and temperature fluctuations, thus solving the problem of operational failure caused by loose connections in conventional ceramic pumps.

[0020] The impeller adopts a spliced ​​structure of segmented blades + first blade. The segmented blades are arranged at a preset angle to the radial direction, and the first blade extends radially along the impeller cover plate. The two work together to form a complete flow channel, which can reduce turbulence and eddy current losses during the medium flow process and reduce friction resistance. The shallow flow channels on the working surfaces of the front and rear guard plates adopt a rounded transition design to further regulate the flow field, avoid particle accumulation, and achieve higher overall conveying efficiency than traditional pumps. The liquid-containing chamber is enclosed by the rear guard plate, the front guard plate, the outer surface of the impeller, and the inner wall of the bushing to form a closed structure. Combined with the guiding effect of the first blade of the impeller cover plate, it avoids medium backflow and stagnation, ensures continuous pressurized delivery of the medium, and improves the flow stability and pressure output accuracy.

[0021] In addition, the core flow components uniformly adopt a three-stage gradient firing process: low temperature debinding (850℃) - medium temperature pre-densification (1650℃) - high temperature final densification (1850℃). Each stage is held at a temperature of 3 hours, which not only avoids defects such as blank cracking and porosity that are easily caused by single high temperature firing, but also improves the density and structural uniformity of the parts layer by layer, ensuring that the dimensional accuracy and material properties of each component are consistent.

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] Figure 1 This is an exploded view of the overall structure in an embodiment of this utility model; Figure 2 This is a schematic diagram of the impeller cover plate in an embodiment of the present utility model; Figure 3 This is a schematic diagram of the impeller metal frame in an embodiment of the present invention; Figure 4 This is a schematic diagram of the impeller body in an embodiment of the present utility model; Figure 5 This is a schematic diagram of the sheath structure in an embodiment of this utility model.

[0024] In the diagram: 1. Pump body casing; 2. Impeller; 21. Impeller cover plate; 210. First blade; 22. Metal frame; 220. Positioning column; 221. Positioning hole; 222. Frame; 23. Impeller body; 230. Split body; 231. Split blade; 232. Round hole; 233. Protrusion; 3. Front guard plate; 4. Rear guard plate; 5. Drive shaft; 6. Sheath; 61. Support shell; 62. Bushing; 7. Pump cover. Detailed Implementation

[0025] like Figure 1-5 As shown: A ceramic pump with silicon carbide flow elements includes a pump body shell 1. A drive shaft 5 is rotatably installed inside the pump body shell 1. An impeller 2 is coaxially fixedly mounted on the drive shaft 5. A sleeve 6 is fixedly connected to one end of the pump body shell 1, and the impeller 2 is adapted to rotatably disposed in the cavity of the sleeve 6. A rear guard plate 4 is sealed between the impeller 2 and the inner wall of the pump body shell 1. A pump cover 7 is fixedly covered at the end of the sleeve 6 away from the pump body shell 1, and a front guard plate 3 is sealed between the impeller 2 and the inner side of the pump cover 7. Both the front guard plate 3 and the rear guard plate 4 are made of silicon carbide powder as raw material and are integrally formed by a three-stage gradient sintering process. The impeller 2 includes an impeller body 23, with a metal frame 22 inside the impeller body 23. Impeller cover plates 21 are bonded to both sides of the impeller body 23. The impeller body 23 and the impeller cover plates 21 are also made of silicon carbide powder as raw material and are integrally formed by a three-stage gradient sintering process.

[0026] In this embodiment, both the pump body shell 1 and the pump cover 7 are integrally formed from high-strength metal material.

[0027] The pump body shell 1 has a cylindrical cavity structure, and the inner wall is provided with an annular stepped surface for positioning and fitting with the sheath 6. A sealing groove is provided at the stepped surface, and an O-ring is built in to achieve a sealed connection with the sheath 6.

[0028] The pump body housing 1 has a flange connection end at one end, and multiple threaded holes are evenly distributed on the flange surface. It is fastened to the sleeve 6 by bolts. At the same time, the flange has a reserved installation positioning groove for the rear guard plate 4.

[0029] The pump body housing 1 has a through hole for the drive shaft 5 at the other end. The hole wall is inlaid with a wear-resistant bushing, which is clearance-fitted with the drive shaft 5 to prevent wear of the shaft hole and reduce the risk of media leakage.

[0030] The pump cover 7 adopts a disc-shaped structure with a medium inlet channel in the center. The inner wall of the channel is rounded to reduce the resistance to medium inflow.

[0031] The pump cover 7 has a positioning stop for the front guard plate 3 on its inner side. The depth of the stop is adapted to the thickness of the front guard plate 3, and a sealing ring groove is opened on the inner side of the stop for installing a corrosion-resistant sealing ring.

[0032] The pump cover 7 has a flange structure on its edge that corresponds to the sleeve 6. The flange holes correspond one-to-one with the sleeve 6 to ensure the coaxiality of the bolt connection.

[0033] The basic structural form, conventional assembly method and general sealing form of the pump body shell 1 and pump cover 7 are common knowledge in the prior art, so the specific details will not be elaborated here.

[0034] Both the front guard plate 3 and the rear guard plate 4 have shallow guide grooves (not shown in the figure) evenly spaced along the circumference on their working surfaces facing the impeller 2 (i.e., the side that is in direct contact with the medium). The depth of the shallow guide grooves is set to 2 mm and the width of the grooves is set to 5 mm. The groove walls and the working surfaces of the front guard plate 3 and the rear guard plate 4 are all designed with rounded transitions, and the transition surfaces are smooth and without sharp edges.

[0035] like Figure 4 As shown, the impeller body 23 is composed of two symmetrically structured parts 230 joined together.

[0036] The split body 230 is made of silicon carbide powder as raw material and is integrally formed by a three-stage gradient firing process. The mating surfaces of the two split bodies 230 are bonded and fixed by a high-temperature resistant ceramic special adhesive. The thickness of the adhesive layer is controlled at 0.1-0.3mm and the fit of the mating surfaces is ≤0.02mm.

[0037] In this embodiment, the adhesive is a silane-modified epoxy-based adhesive, which is commercially available.

[0038] The silane-modified epoxy ceramic special binder contains a silane coupling agent in its molecular structure that can chemically react with the hydroxyl groups on the surface of silicon carbide ceramics to form chemical bonds (rather than simple physical adsorption), which significantly improves the interfacial bonding strength between the binder and the component 230 (shear strength ≥15MPa). At the same time, the binder has excellent high temperature resistance (long-term temperature resistance ≥300℃), acid and alkali corrosion resistance, and media erosion resistance, which can resist the erosion of particulate corrosive media transported by ceramic pumps and avoid separation caused by aging and degradation of the adhesive layer.

[0039] The outer surface of the split body 230 has a ring array of multiple protrusions 233, and multiple circular holes 232 are opened on the outer surface of the split body 230 near the multiple protrusions 233.

[0040] The circular holes 232 and the protrusions 233 correspond one-to-one and are evenly arranged along the circumference of the split body 230.

[0041] The outer circular surface of the split body 230 is evenly spaced with multiple blades 231. Each blade 231 extends outward at a certain angle to the radial direction of the split body 230, and adjacent blades 231 are symmetrically arranged at equal angles, with the center angles of adjacent blades 231 being consistent.

[0042] With this design, when the two parts 230 are fixed together by adhesive, the corresponding blades 231 on the two parts can be spliced ​​together to form a complete impeller blade. Each blade after splicing continues the arrangement angle of the blades and extends outward at a preset angle with the radial direction of the impeller body 23, forming a blade structure that conforms to fluid dynamics.

[0043] When the impeller body 23 rotates at high speed with the drive shaft 5, the blades generate axial thrust and radial centrifugal force on the medium (liquid and particulate medium) inside the sheath 6. Through the guiding and squeezing action of the blades, the medium is transported from the inlet end at the center of the impeller body 23 to the outlet end at the outer edge of the blades, thereby realizing continuous pressurization and directional flow of the medium. The outer surface of the sheath 6 is provided with a discharge port, which corresponds to the outlet end of the outer edge of the blade.

[0044] The preset angle between the blade and the radial direction, along with the smooth curved surface design, can reduce turbulence and eddy current losses during the medium flow process, reduce frictional resistance, and prevent particulate media from accumulating on the blade surface, thereby improving conveying efficiency.

[0045] like Figure 3 As shown, the metal frame 22 includes a frame 222, which is made of high-toughness stainless steel.

[0046] Positioning holes 221 are provided on the surface of the frame 222 at positions corresponding to the protrusions 233 of the impeller body 230.

[0047] The outer dimensions of the protrusion 233 are adapted to the inner dimensions of the positioning hole 221. The two adopt a transition fit to achieve a tight fit. When the two parts 230 are joined and bonded, the corresponding protrusion 233 is simultaneously inserted into the positioning hole 221 on the frame 222 to form circumferential positioning and restrict the circumferential displacement of the parts 230 relative to the metal frame 22.

[0048] The metal frame 22 has positioning posts 220 integrally formed at positions on both end faces (the faces that fit with the two parts 230) that correspond one-to-one with the round holes 232 of the parts 230.

[0049] The outer diameter of the positioning post 220 is adapted to the diameter of the circular hole 232, and the two adopt a transition fit to achieve precise positioning.

[0050] When the two parts 230 are joined and bonded, the positioning posts 220 on both sides of the metal frame 22 are inserted into the corresponding round holes 232 of the parts 230 to form axial positioning, ensuring the coaxiality and docking accuracy of the two parts 230.

[0051] By adopting the above-mentioned dual positioning structure design, precise positioning and bidirectional constraint between the metal frame 22 and the two parts 230 can be achieved. During the bonding process of the two parts 230, the circumferential positioning of the parts 230 relative to the metal frame 22 can be effectively restricted by the circumferential positioning of the protrusion 233 and the positioning hole 221. At the same time, the axial positioning of the positioning post 220 and the circular hole 232 can be used to strictly ensure the coaxiality, fitting degree and splicing accuracy of the two parts 230 and the blade 231, avoiding misalignment and displacement during bonding. At the same time, after the bonding and curing, the positioning structure can form a cooperative force system with the bonding layer, which can evenly transfer the torque and media impact load during impeller rotation to the metal frame 22, reduce stress concentration at the bonding surface and splicing point, further improve the connection stability and overall structural strength of the impeller body 23 and the metal frame 22, and ensure that the impeller maintains structural precision and reliable operation under long-term high-speed rotation conditions.

[0052] With this design, the metal frame 22 can serve as the core load-bearing and positioning support component of the impeller body 23, forming a composite structure with the impeller body 23 that is rigid and flexible, precisely positioned, and shares the load. This not only makes up for the material defects of silicon carbide, which is brittle and has poor impact resistance, but also provides multiple structural guarantees for the assembly and operation of the impeller body 23. Its core role runs through the entire process of the impeller body 23's bonding and molding, precise assembly, and high-speed operation.

[0053] Impeller cover plates 21 are bonded to both ends of the impeller body 23. The adhesive used is the same silane-modified epoxy ceramic adhesive used for docking with the split body 230, so as to achieve reliable fixation.

[0054] The impeller cover plate 21 is made of silicon carbide powder as raw material and is integrally formed by a three-stage gradient sintering process, and its material and process are consistent with those of the impeller body 23.

[0055] On the side surface of each of the two impeller cover plates 21 that is away from the impeller body 23, there are multiple first blades 210 arranged in a ring array near the outer edge. Each first blade 210 extends outward along the radial direction of the impeller cover plate 21.

[0056] like Figure 5 As shown, the sheath 6 includes a support shell 61. The end face of the support shell 61 near the pump body shell 1 is fixedly and sealed to one end of the pump body shell 1 by bolts, and the side of the support shell 61 away from the pump body shell 1 is fixedly and sealed to the pump cover 7 by bolts.

[0057] The inner wall of the support shell 61 is bonded with a bushing 62, which is made of silicon carbide powder as raw material and integrally formed by a three-stage gradient sintering process, and is consistent with the impeller body 23 in terms of material and process.

[0058] The impeller 2 is adapted to rotate within the inner cavity of the bushing 62. The rear guard plate 4, the front guard plate 3, the outer surface of the impeller 2, and the inner wall of the bushing 62 together form a sealed liquid cavity. After the conveying medium enters the liquid cavity, it is pressurized and guided by the high-speed rotation of the impeller 2, and finally continuously output through the outlet end of the pump body.

[0059] The support shell 61 is made of QT450-10 ductile iron through casting, which has excellent structural rigidity, impact resistance and adaptability to working conditions. As the core load-bearing and positioning base of the sheath 6, the support shell 61 can withstand the reaction force generated by the impact of the medium and the backflow when the impeller rotates at high speed, providing a stable structural support for the operation of the impeller 2, preventing radial offset and shaking during the rotation of the impeller, and ensuring the coaxiality of the impeller and the sheath.

[0060] At the same time, when the impeller 2 drives the medium to rotate synchronously in the liquid chamber, the first blade 210 can quickly guide the medium attached to the surface of the impeller cover plate 21 to the flow channel of the main blade of the impeller, so that the medium can be pressurized and transported with the main blade, and avoid the medium from stagnating on the surface of the cover plate.

[0061] The front guard plate 3, rear guard plate 4, impeller body 23, impeller cover plate 21, and bushing 62 are manufactured using a three-stage gradient firing process: low-temperature glue removal, medium-temperature pre-densification, and high-temperature final densification. The firing temperature in the low-temperature glue removal stage is set at 850℃, the temperature in the medium-temperature pre-densification stage is set at 1650℃, and the temperature in the high-temperature final densification stage is set at 1850℃. Each stage is held at this temperature for 3 hours to complete the firing process.

[0062] This design enables the step-by-step forming of silicon carbide powder raw materials from green body to dense ceramic parts. It avoids defects such as cracking, deformation, and porosity that are prone to occur in single high-temperature firing, and can improve the density and structural uniformity of the parts layer by layer. The low-temperature debinding stage can fully remove organic binders and moisture from the green body, avoiding internal cracks caused by the rapid escape of volatiles during subsequent high-temperature firing. The medium-temperature pre-densification stage allows the powder particles to be initially sintered and bonded to form a green body with basic structural strength, laying the structural foundation for high-temperature final densification. The high-temperature final densification stage allows the powder particles to fully diffuse and sinter, greatly improving the density of the parts and ultimately obtaining silicon carbide ceramic parts with high hardness, high wear resistance, and erosion resistance.

[0063] Each stage is kept at a uniform temperature for 3 hours to ensure uniform temperature inside and outside the component, avoid local cracking caused by thermal stress due to temperature difference, ensure the dimensional accuracy and structural integrity of core flow components such as front guard plate 3 and rear guard plate 4, and ensure that all components are manufactured using the same process to ensure consistent material performance, improve assembly compatibility and overall operational stability, and meet the harsh working conditions of ceramic pumps conveying media containing particles and corrosive media.

[0064] For those skilled in the art, any changes, modifications, substitutions, and variations made to the embodiments based on the teachings of this utility model, without departing from the principles and spirit of this utility model, still fall within the protection scope of this utility model.

Claims

1. A ceramic pump with silicon carbide flow elements, comprising a pump body housing (1), characterized in that: The pump body shell (1) is rotatably connected to a drive shaft (5), and an impeller (2) is coaxially fixedly mounted on the drive shaft (5). A sleeve (6) is fixedly connected to one end of the pump body shell (1), and the impeller (2) is adapted to rotate within the cavity of the sleeve (6). A rear guard plate (4) is sealed between the impeller (2) and the inner wall of the pump body shell (1). A pump cover (7) is fixedly covered at the end of the sleeve (6) away from the pump body shell (1), and a front guard plate (3) is sealed between the impeller (2) and the inner side of the pump cover (7). Both the front guard plate (3) and the rear guard plate (4) are made of silicon carbide powder as raw material and are integrally formed by a three-stage gradient sintering process. The impeller (2) includes an impeller body (23), a metal skeleton (22) is provided inside the impeller body (23), and impeller cover plates (21) are bonded to both sides of the impeller body (23). The impeller body (23) and the impeller cover plates (21) are also made of silicon carbide powder as raw material and are integrally formed by a three-stage gradient sintering process.

2. A ceramic pump with a silicon carbide flow element according to claim 1, characterized in that: The impeller body (23) is composed of two symmetrically structured parts (230) joined together.

3. A ceramic pump with a silicon carbide flow element according to claim 2, characterized in that: The split body (230) is made of silicon carbide powder as raw material and is integrally formed by a three-stage gradient sintering process, and the mating surfaces of the two split bodies (230) are bonded and fixed.

4. A ceramic pump with a silicon carbide flow element according to claim 3, characterized in that: The outer surface of the split body (230) has a ring array of multiple protrusions (233), and multiple circular holes (232) are opened on the outer surface of the split body (230) near the multiple protrusions (233). The circular holes (232) correspond one-to-one with the protrusions (233) and are evenly arranged along the circumference of the split body (230).

5. A ceramic pump with a silicon carbide flow element according to claim 4, characterized in that: The outer surface of the split body (230) is evenly spaced with multiple blades (231). Each blade (231) extends outward at a certain angle to the radial direction of the split body (230), and adjacent blades (231) are symmetrically arranged at equal angles, with the center angles of adjacent blades (231) being consistent.

6. A ceramic pump with a silicon carbide flow element according to claim 5, characterized in that: The metal frame (22) includes a frame (222), and positioning holes (221) are provided at positions on the surface of the frame (222) that correspond one-to-one with the protrusions (233) of the impeller body (230).

7. A ceramic pump with a silicon carbide flow element according to claim 6, characterized in that: The external dimensions of the protrusion (233) are adapted to the internal dimensions of the positioning hole (221), and the two are fitted together by transition.

8. A ceramic pump with a silicon carbide flow element according to claim 7, characterized in that: The metal skeleton (22) has a positioning post (220) integrally formed at the position corresponding to the round hole (232) of the split body (230) on both sides end face. The outer diameter of the positioning post (220) is adapted to the diameter of the round hole (232), and the two adopt a transition fit to achieve precise positioning.

9. A ceramic pump with a silicon carbide flow element according to claim 8, characterized in that: Impeller cover plates (21) are bonded to both ends of the impeller body (23). The impeller cover plates (21) are made of silicon carbide powder as raw material and are integrally formed by a three-stage gradient firing process. The material and process are consistent with those of the impeller body (23). The two impeller cover plates (21) on the side surface opposite to the impeller body (23) are provided with a plurality of first blades (210) arranged in a ring array near the outer edge, and each first blade (210) extends outward along the radial direction of the impeller cover plate (21).

10. A ceramic pump with a silicon carbide flow element according to claim 9, characterized in that: The sheath (6) includes a support shell (61), and a bushing (62) is bonded to the inner wall of the support shell (61). The bushing (62) is made of silicon carbide powder as raw material and is integrally formed by a three-stage gradient sintering process.

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