A solid-liquid separation structure for ceramic matrix composite chips

Abstract

The application discloses a solid-liquid separation structure for ceramic matrix composite chips, and belongs to the technical field of solid-liquid separation of cyclones, and aims to solve the core problem of low separation precision and high fine particle escape rate of traditional cyclones. The technical scheme comprises a cone section, a column section and an inlet end of the cyclone, spiral micro-grooves are uniformly processed on the inner walls of the cone section and the column section, a tapered flow guide fin is arranged at the tail end of the inlet end, and the flow guide fin is integrally formed with the cyclone. The spiral micro-grooves induce local secondary cyclone to prolong the particle sedimentation path, the tapered flow guide fin optimizes the initial flow field, and the two are combined to significantly improve the separation precision, reduce the fine particle escape rate, reduce the equipment wear and energy loss, and meet the separation requirements of ceramic matrix composite chips with different particle sizes.

Description

Technical Field

[0001] This invention relates to the field of hydrocyclone solid-liquid separation technology, and more particularly to a solid-liquid separation structure for ceramic matrix composite chip cuttings. Background Technology

[0002] Ceramic matrix composites (SiCf / SiC) possess excellent properties such as high hardness, high strength, high temperature resistance, and corrosion resistance, and are widely used in high-end manufacturing fields such as aerospace and precision equipment. During grinding and cutting processes, these materials generate a large amount of cutting fluid mixture containing chips of different particle sizes. To achieve cutting fluid recycling, reduce processing costs, and ensure machining cleanliness, the chip mixture needs to be separated into solid and liquid phases using a hydrocyclone.

[0003] Currently, traditional hydrocyclones mostly employ smooth cylindrical sections, conical inner walls, and fixed direct-inlet structures, relying on a single centrifugal swirling action to achieve solid-liquid separation. This type of structure is suitable for the simple separation of conventional metal chips and large particle impurities. However, ceramic matrix composite chips have characteristics such as high density, high hardness, wide particle size distribution (20μm~150μm), and easy agglomeration of fine particles. Therefore, when traditional hydrocyclones are applied to the separation of this type of special chip, they suffer from technical problems such as extremely low separation accuracy and persistently high escape rate of fine particles. Summary of the Invention

[0004] The main objective of this invention is to provide a solid-liquid separation structure for ceramic matrix composite chipping, aiming to solve the technical problems of extremely low separation accuracy and high fine particle escape rate when traditional hydrocyclones are applied to ceramic matrix composites.

[0005] To achieve the above objectives, the present invention provides a solid-liquid separation structure for ceramic matrix composite chipping, comprising a conical section, a cylindrical section, and an inlet end of a hydrocyclone. The inner walls of the conical segment and the cylindrical segment are uniformly machined with spiral micro-grooves; The inlet end is provided with tapered guide fins, which are integrally formed with the cyclone separator.

[0006] Optionally, the cross-section of the spiral microgroove is trapezoidal, with an upper base width of 1-3 mm, a lower base width of 60%-80% of the upper base width, a depth of 0.5-2 mm, a spiral angle of 60°-75°, and a pitch of 10%-15% of the hydrocyclone diameter.

[0007] Optionally, the conical segment has 3-6 spiral microgrooves, and the cylindrical segment has 2-4 spiral microgrooves; the total length of the grooves in the conical segment accounts for 20%-25% of the effective separation area of ​​the hydrocyclone, and the total length of the grooves in the cylindrical segment accounts for 10%-15% of the effective separation area of ​​the hydrocyclone.

[0008] Optionally, the thickness of the tapered guide fin is 1-2 mm.

[0009] Optionally, the number of tapered guide fins is 4-8, the height of the tapered guide fins linearly decreases from 5mm at the inlet to 1mm at the end, and the tilt angle dynamically increases from 30° to 45°; the length of the guide fins accounts for 50%-70% of the diameter of the feed pipe, and the spacing between adjacent fins is 8%-12% of the circumference of the feed pipe.

[0010] Optionally, the depth of the spiral microgrooves is positively correlated with the chip size: When the chip size is >50μm, the groove depth is set to 1-2mm; When the chip size is ≤50μm, the groove depth should be adjusted to 0.5-1mm.

[0011] Optionally, the distribution density of the spiral microgrooves in the conical section is 1.5-2 times that in the cylindrical section, and the spiral angle of the grooves in the conical section is 5°-10° larger than that in the cylindrical section.

[0012] Optionally, the tapering curve of the tapering guide fin is a quadratic function curve, and its height change satisfies the formula:

[0013] in, , This is the shrinkage coefficient, with a value ranging from 0.02 to 0.05. This represents the distance along the direction of fluid flow.

[0014] The beneficial effects that this invention can achieve are as follows: This structure, through a synergistic design of spiral microgrooves on the inner walls of the conical and cylindrical sections of the hydrocyclone and tapered guide fins at the inlet end, simultaneously optimizes the flow field at its source and enhances particle settling. The guide fins smoothly increase fluid velocity and prevent fine particle agglomeration caused by turbulent flow, while the spiral microgrooves induce local secondary swirling, significantly extending the centrifugal settling path of the cutting particles and increasing the relative velocity difference between the particles and the fluid. This results in a significant improvement in the solid-liquid separation accuracy of ceramic matrix composite chip cuttings, greatly reducing the escape rate of fine chips, and enabling the recovered cutting fluid to directly meet the requirements for recycling in precision machining. Attached Figure Description

[0015] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0016] Figure 1 This is a three-dimensional structural schematic diagram of a solid-liquid separation structure for ceramic matrix composite chip provided in an embodiment of the present invention; Figure 2 A partial sectional view of the column segment and the cone segment provided in an embodiment of the present invention; Figure 3 This is a partial cross-sectional schematic diagram of the entrance structure provided in an embodiment of the present invention.

[0017] Figure label: 1. Inlet; 2. Inlet section; 3. Conical section; 4. Bottom outlet; 5. Column section; 6. Overflow section; 7. Overflow outlet.

[0018] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0021] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0023] Example refer to Figures 1-3 This invention provides a solid-liquid separation structure for ceramic matrix composite chip processing, applied to the solid-liquid separation of chips and cutting fluid generated during ceramic matrix composite processing. The solid-liquid separation structure is designed based on the hydrocyclone principle and includes an inlet section 2, a column section 5, a cone section 3, an underflow port 4, and an overflow section 6. The inlet section 2 is tangentially connected to the sidewall of the column section 5. The lower end of the column section 5 is connected to the upper end of the cone section 3. The lower end of the cone section 3 is provided with the underflow port 4, and the upper end of the column section 5 is provided with the overflow section 6. The top of the overflow section 6 is provided with an overflow port 7. The inner walls of the column section 5 and the cone section 3 are uniformly machined with spiral microgrooves. The end of the inlet section 2 is provided with 4-8 tapered guide fins, which are integrally formed with the hydrocyclone.

[0024] This invention proposes a solid-liquid separation structure for ceramic matrix composite chips. By inducing local secondary swirling through helical microgrooves on the inner wall of a hydrocyclone, the centrifugal settling path of the chip particles is extended. Simultaneously, tapered guide fins at the inlet optimize the initial flow field distribution. The synergistic effect of these two elements significantly improves the separation accuracy of the ceramic matrix composite chips and reduces the escape rate of fine particles. The vortex retention zone formed by the helical microgrooves reduces direct impact of chip particles on the inner wall of the hydrocyclone, reducing equipment wear and extending service life. The tapered guide fins achieve a smooth increase in fluid velocity, reducing energy loss caused by abrupt changes in the flow field and improving operating efficiency. Through the gradient groove design and adjustable operating parameters, the separation requirements of ceramic matrix composite chips with different particle sizes can be met.

[0025] It should be noted that, as Figure 1As shown, the axial direction of the hydrocyclone is vertical. The mixture enters the column section 5 tangentially from the inlet section 2 and forms a rotating flow field. Under the action of centrifugal force, the denser cutting particles move towards the wall and are eventually discharged from the bottom outlet 4, while the less dense cutting fluid converges towards the center and is discharged from the top overflow outlet 7, thus achieving solid-liquid separation.

[0026] Furthermore, ceramic matrix composite chips have the characteristics of high density (approximately 3.2 × 10³ kg / m³), high hardness, and wide particle size distribution (typically 20-150 μm). When traditional hydrocyclones process such chips, they are prone to problems such as high fine particle escape rate, severe equipment wear, and large energy loss. The embodiments of the present invention have made targeted structural improvements to address these problems.

[0027] refer to Figure 2 In an exemplary embodiment, H is the depth of the spiral microgroove, d is the maximum upper bottom width of the spiral microgroove, b is the minimum lower bottom width of the spiral microgroove, β is the spiral angle of the spiral microgroove, P is the pitch of the spiral microgroove, D is the diameter of the cyclone separator, h is the height of the tapered guide fin, s is the length of the tapered guide fin, and α is the tilt angle of the tapered guide fin.

[0028] The spiral microgroove has a trapezoidal cross-section, with an upper base width d of 1-3 mm, a lower base width b of 60%-80% of the upper base width, a depth H of 0.5-2 mm, a spiral angle β of 60°-75°, and a pitch P of 10%-15% of the hydrocyclone diameter D.

[0029] Specifically, the trapezoidal cross-section with a wider top and narrower bottom can form a vortex retention zone. On the one hand, the wider top facilitates the fluid to enter the groove and induces local secondary swirling flow. On the other hand, the narrower bottom can enhance the vortex intensity and reduce particle jamming. At the same time, this structure is also convenient for using integrated manufacturing processes such as 3D printing to ensure structural strength.

[0030] The ratio of pitch P to hydrocyclone diameter D ensures that the grooves are evenly distributed on the inner wall of the hydrocyclone, which can form a continuous disturbance field without causing excessive flow field resistance and energy loss due to excessively dense grooves.

[0031] In an exemplary embodiment, the conical segment 3 has 3-6 spiral microgrooves, and the columnar segment 5 has 2-4 spiral microgrooves; the total length of the conical segment grooves accounts for 20%-25% of the effective separation area of ​​the hydrocyclone, and the total length of the columnar segment grooves accounts for 10%-15% of the effective separation area of ​​the hydrocyclone.

[0032] Specifically, section 5, serving as the pretreatment zone, has a relatively small number of grooves that primarily guide the flow field and provide initial acceleration, directing particles towards the wall while preventing excessive disturbance that could cause fine particles to flow back. Section 3, serving as the main separation zone, has a larger number of grooves that form a dense secondary vortex network, enhancing centrifugal force, extending the particle settling path, and promoting the settling of coarse particles. This gradient distribution design, from sparse to dense, ensures that the separation load matches the structural capacity, thereby improving the overall separation efficiency.

[0033] In an exemplary embodiment, the distribution density of the spiral microgrooves in the conical segment is 1.5-2 times that in the cylindrical segment, and the helix angle of the grooves in the conical segment is 5°-10° larger than that in the cylindrical segment.

[0034] Specifically, the fluid velocity in cone section 3 increases as the cross-section decreases, and the larger helix angle maintains a sufficient tangential velocity component to ensure centrifugal separation. In column section 5, the helix angle is smaller, resulting in moderate secondary swirling intensity, preventing turbulence that could cause fine particles to escape, while also reducing energy loss. This gradient design of the helix angle creates a gradual swirling intensity gradient, avoiding energy loss caused by abrupt changes in the flow field.

[0035] In an exemplary embodiment, the depth of the spiral microgroove is positively correlated with the chip size: when the chip size is >50μm, the groove depth is set to 1-2mm; when the chip size is ≤50μm, the groove depth is adjusted to 0.5-1mm.

[0036] Specifically, coarse particles (>50μm) have large mass and strong inertia, requiring deeper grooves to provide sufficient centrifugal settling space and prevent them from being carried away by the main fluid. Fine particles (≤50μm) have small mass and are prone to agglomeration; shallower grooves can break up particle agglomeration through appropriate secondary swirling, while reducing the residence time of particles in the groove, thus balancing separation efficiency and accuracy. This design, which allows the groove depth to be adjusted according to the chip size, enables this structure to adapt to ceramic matrix composite chips with different particle size distributions.

[0037] refer to Figure 3 In an exemplary embodiment, the thickness of the tapered guide fin is 1-2 mm, the height h linearly decreases from 5 mm at the inlet to 1 mm at the end, and the tilt angle α dynamically increases from 30° to 45°; the length s of the guide fin accounts for 50%-70% of the diameter of the feed pipe, and the spacing between adjacent fins is 8%-12% of the circumference of the feed pipe.

[0038] Specifically, the guide fins adopt a design with gradually varying height and dynamically changing angle, which can smoothly increase the fluid velocity from 0.5-2.0 m / s at the inlet to 3-8 m / s, avoiding flow field turbulence and fine particle agglomeration caused by sudden changes in velocity. The small 30° angle at the inlet reduces the impact resistance of the fluid on the inlet section, while the large 45° angle at the end enhances the swirling guidance, so that the fluid has formed a stable rotation trend when it enters the column section 5, reducing the energy consumption for flow field adjustment in the swirling chamber.

[0039] The design of the spacing between adjacent fins ensures that the fluid can be evenly distributed between the fins, avoiding local wear caused by uneven flow rate; the selection of fin thickness takes into account both structural strength and fluid resistance, while also adapting to the process requirements of integrated 3D printing.

[0040] In an exemplary embodiment, the tapering curve of the tapering guide fin is a quadratic function curve, and its height change satisfies the formula:

[0041] in, , This is the shrinkage coefficient, with a value ranging from 0.02 to 0.05. This represents the distance along the direction of fluid flow.

[0042] Specifically, compared to linear gradient, the height change rate of the quadratic function curve gradually increases, which can achieve a smoother flow velocity increase, further reduce the flow field turbulence, and reduce the agglomeration rate of fine particles; the range of the convergence coefficient k can be adjusted according to the inlet flow velocity, with a smaller k value used at low flow velocities and a larger k value used at high flow velocities to ensure the best flow guiding effect.

[0043] It should be noted that the core advantage of this invention lies in the three-stage synergy between the spiral microgrooves and the tapered guide fins, as well as the gradient synergy between the conical and cylindrical spiral grooves, forming a complete and efficient separation link: The primary synergy is the synergy between the guide fins and the conical spiral groove: the guide fins accelerate the fluid to a stable tangential velocity of 3-8 m / s, providing a high swirling foundation for the conical spiral groove and avoiding the consumption of additional energy due to the instability of the initial flow field in the secondary swirling of the conical section; the conical spiral groove induces strong secondary swirling on the basis of high swirling, which increases the relative velocity between coarse particles and fluid by 20%-40% and extends the centrifugal settling time to 1.5-2 times, significantly enhancing the separation effect of coarse particles.

[0044] The secondary synergy is the synergy between the conical section and the cylindrical section spiral groove: the cylindrical section separates more than 80% of the coarse particles first, reducing the processing load of the conical section; the conical section receives the remaining fine particle fluid through weak secondary swirling, avoiding fine particles from entering the cylindrical section and competing with coarse particles for separation space; at the same time, the difference in spiral angle between the conical section and the cylindrical section forms a swirling intensity gradient, avoiding energy loss caused by abrupt changes in the flow field.

[0045] The three-level collaboration is a collaboration of the entire structure: the guide fins optimize the initial flow field and reduce the impact wear of the fluid on the hydrocyclone inlet; the vortex retention zone of the spiral groove restricts the direct impact of particles on the inner wall, reducing the wear rate of the cone and column sections by more than 30%; the integrated 3D printed fins have no assembly gaps, avoiding local scouring wear caused by fluid leakage.

[0046] In one specific embodiment, the main structural parameters of the hydrocyclone are as follows: the diameter D of the column section 5 is 150 mm, and the height is twice the diameter; the cone section 3 is composed of a single-stage cone angle of 20°; the inlet section 2 adopts a tangential inlet design, with an inlet width of 0.75 times the diameter and an inlet height of 0.2 times the diameter; the diameter of the underflow outlet 4 is 0.25D; the overflow pipe insertion depth of the overflow section 6 is 0.8D, and the overflow pipe outlet diameter is 0.25D.

[0047] The corresponding structural parameters are as follows: the column section 5 is provided with 3 spiral microgrooves, the upper bottom width d is 2.5mm, and the pitch P is 15mm; the cone section 3 is provided with 5 spiral microgrooves, the depth H is 1.2mm, to accommodate chips with a particle size >50μm, the spiral angle β is 72°, and the pitch P is 18mm, which is 12% of the hydrocyclone diameter; the inlet section 2 is provided with 6 tapered guide fins, the length s is 90mm, the thickness is 1.8mm, and the tapering coefficient k=0.03.

[0048] Based on the above embodiments, this invention also provides a solid-liquid separation method for ceramic matrix composite material chips, applied to the above-mentioned solid-liquid separation structure. This method specifically includes the following steps: S100. The mixture containing ceramic matrix composite material chips is fed into the inlet section 2 at a set flow rate. The mixture is accelerated in a stepwise manner by the tapered guide fins to form a stable rotating flow field with a tangential velocity of 3-8 m / s. S200, the rotating flow field enters the column section 5 and the cone section 3, the spiral micro-grooves induce local secondary swirling flow, increase the relative velocity between particles and fluid and prolong the centrifugal settling time of coarse particles. S300: By adjusting the pressure difference between the underflow port 4 and the overflow pipe, the escape rate of fine particles is controlled, and the solid-liquid separation of ceramic matrix composite material chips is finally achieved. Coarse chips are discharged from the underflow port 4, and clear cutting fluid is discharged from the overflow port 7.

[0049] In an exemplary embodiment, the inlet flow rate of the mixture is 0.5-2.0 m / s. This flow rate range is suitable for the high density characteristics of ceramic matrix composite chip. If the flow rate is too low, the centrifugal force is insufficient to drive the coarse particles to settle. If the flow rate is too high, the energy loss is large and the escape rate of fine particles increases. The spiral microgroove increases the relative velocity between the particles and the fluid by 20%-40%, and extends the centrifugal settling time of coarse particles to 1.5-2 times. The pressure difference between the underflow port 4 and the overflow pipe is adjustable in the range of 0.05-0.2 MPa. By adjusting the pressure difference, the rising speed of the fluid in the overflow pipe can be controlled. The greater the pressure difference, the stronger the force of the coarse particles discharged from the underflow port, and the higher the probability that fine particles are pushed back into the separation area.

[0050] In a specific measurement embodiment, the chips in the inlet slurry were SiCf / SiC composite materials with a density of 3.2 × 10³ kg / m³ and a particle size distribution of 20-150 μm. The operating parameters were set as follows: inlet flow velocity 1.2 m / s and underflow pressure 0.12 MPa. After operating according to the above structural and operating parameters, the experimenters used a laser particle size analyzer to measure the slurry discharged from underflow port 4 and overflow port 7, respectively. The calculated solid-liquid separation efficiency of the ceramic matrix composite chip was ≥60%, and the fine particle escape rate was ≤5%, achieving the expected separation effect.

[0051] It should be understood that other structures of the hydrocyclone not described in detail in the embodiments of the present invention (such as the specific structure of the overflow pipe, the adjustment device of the underflow port, etc.) are all conventional designs in the art and will not be described in detail here.

[0052] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A solid-liquid separation structure for ceramic matrix composite chip cuttings, characterized in that, This includes the conical section, cylindrical section, and inlet end of the hydrocyclone. The inner walls of the conical segment and the cylindrical segment are uniformly machined with spiral micro-grooves; The inlet end is provided with tapered guide fins, which are integrally formed with the cyclone separator.

2. The solid-liquid separation structure for ceramic matrix composite chip as described in claim 1, characterized in that, The spiral microgroove has a trapezoidal cross-section, with an upper base width of 1-3 mm, a lower base width of 60%-80% of the upper base width, a depth of 0.5-2 mm, a spiral angle of 60°-75°, and a pitch of 10%-15% of the hydrocyclone diameter.

3. The solid-liquid separation structure for ceramic matrix composite chip as described in claim 1, characterized in that, The conical segment has 3-6 spiral microgrooves, and the cylindrical segment has 2-4 spiral microgrooves; the total length of the grooves in the conical segment accounts for 20%-25% of the effective separation area of ​​the hydrocyclone, and the total length of the grooves in the cylindrical segment accounts for 10%-15% of the effective separation area of ​​the hydrocyclone.

4. The solid-liquid separation structure for ceramic matrix composite chip as described in claim 1, characterized in that, The thickness of the tapered guide fins is 1-2 mm.

5. The solid-liquid separation structure for ceramic matrix composite chip as described in claim 1, characterized in that, The number of tapered guide fins is 4-8, the height of the tapered guide fins linearly decreases from 5mm at the inlet to 1mm at the end, and the tilt angle dynamically increases from 30° to 45°; the length of the guide fins accounts for 50%-70% of the diameter of the feed pipe, and the spacing between adjacent fins is 8%-12% of the circumference of the feed pipe.

6. The solid-liquid separation structure for ceramic matrix composite chip as described in claim 1, characterized in that, The depth of the spiral microgrooves is positively correlated with the chip size: When the chip size is >50μm, the groove depth is set to 1-2mm; When the chip size is ≤50μm, the groove depth should be adjusted to 0.5-1mm.

7. The solid-liquid separation structure for ceramic matrix composite chip as described in claim 1, characterized in that, The distribution density of the spiral microgrooves in the conical section is 1.5-2 times that in the cylindrical section, and the spiral angle of the grooves in the conical section is 5°-10° larger than that in the cylindrical section.

8. The solid-liquid separation structure for ceramic matrix composite chip as described in claim 1, characterized in that, The tapering curve of the tapering guide fin is a quadratic function curve, and its height change satisfies the formula: in, , This is the shrinkage coefficient, with a value ranging from 0.02 to 0.

05. This represents the distance along the direction of fluid flow.

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