A method of particle separation and classification and apparatus therefor

Abstract

The application provides a method and device for particle separation and classification. A centrifugal force is applied to a suspension containing particles, and a second force perpendicular to the centrifugal sedimentation direction of the particles in the centrifugal separation is superimposed on the particles, thereby generating a secondary external acceleration to cause the particles to generate a Coriolis acceleration. By using the technical scheme of the application, the Coriolis effect is used to generate a secondary acceleration on the particles in the centrifugal field inside the fluid, which is perpendicular to the sedimentation direction of the particles, and the superimposed acceleration causes the particles to generate a motion perpendicular to the radial sedimentation motion direction of the particles in the fluid, thereby reducing the friction between the particles, allowing smaller and lighter particles to be released, improving the particle separation and classification performance, and achieving more accurate particle size classification. Especially in the case of high concentration, the adverse effects of the blocked sedimentation of the particles are eliminated, and better separation and classification effects are achieved.

Description

Technical Field

[0001] This invention relates to the field of particle separation and classification technology, to a hydrocyclone, and more particularly to a method and apparatus for particle separation and classification. Background Technology

[0002] Hydrocyclones are common separation and classification devices in mining and environmental protection processes. The working principle of a hydrocyclone is to apply a high radial velocity to a suspension, causing it to be subjected to centrifugal force, thereby achieving particle separation. The particles settle under the centrifugal acceleration perpendicular to the hydrocyclone wall. However, if the solids concentration is high, settling will be hindered, meaning that the separation between particles will be mutually impeded, preventing linear settling motion. This effect is particularly pronounced when there is a mixture of two or more particles with different densities, resulting in poor separation and classification performance using hydrocyclones.

[0003] It is well known that particle motion at high concentrations can be improved through superimposed secondary motion. This secondary motion overcomes the static friction between particles, allowing them to move at different settling velocities based on size, density, and shape. Existing separation processes generally employ additional forces, either continuously or discontinuously, to improve particle classification. For example, in an upflow classifier, the suspension is introduced into a tank, particles settle to the bottom, and the water flow is opposite to the particle settling direction, increasing the relative velocity between the fluid and particles and generating turbulence. Turbulence overcomes the static friction between particles, thereby increasing the overall settling velocity and improving classification efficiency. A centrifugal jig is another application of introducing secondary forces, causing the suspension to undergo primary separation under centrifugal force. Particles settle radially against the rotating drum wall, and rinsing water is pulsed in through openings in the drum wall. This countercurrent leads to the release of particle clusters, causing the particles to settle at different velocities as a whole. Another method is a centrifugal concentrator, where the suspension is introduced into a rotating bowl with openings in the bowl wall through which a continuous flow of water is introduced. The direction of water flow is opposite to the direction of main sedimentation, generating turbulence, which overcomes the static friction between particles.

[0004] The existing solutions described above all rely on introducing additional fluid flow to transfer secondary forces, which dilutes the material and increases process water consumption. Furthermore, using auxiliary fluid flow requires the injected fluid to have a velocity approximating the total velocity of the suspension and to be opposite to the particle settling direction. This limits the application of gravity settling in tanks and centrifuges where the velocity gradient between the suspension and the separator wall is small. For hydrocyclones, injecting water from the stationary outer wall into the rotating flow of the suspension in the opposite direction of settling is not feasible. Summary of the Invention

[0005] To address the above technical problems, this invention discloses a method and apparatus for particle separation and classification. This method utilizes the Coriolis effect, resulting in better particle separation and classification performance. It can be used for the classification treatment of suspensions with high solid concentrations, and it does not require additional rinsing water, making it more environmentally friendly and reducing costs.

[0006] The technical solution adopted by this invention is as follows:

[0007] A method for particle separation and classification involves applying centrifugal force to a suspension containing particles and superimposing a second force perpendicular to the centrifugal settling direction onto the particles during centrifugal separation, generating a secondary external acceleration that causes the particles to undergo Coriolis acceleration. Further, the secondary acceleration can be a linear reciprocating acceleration, a constant centrifugal acceleration, or a reciprocating tangential acceleration.

[0008] This technical solution utilizes the Coriolis effect to apply a secondary external acceleration perpendicular to the centrifugal settling direction to the centrifugally separated fluid, achieving Coriolis acceleration of the particles and improving the method of particulate matter separation and classification. Furthermore, this method reduces the concentration of light, small particles in the underflow and large particles in the overflow, thereby improving the particle size distribution of the suspension and allowing the separation device to operate at higher solids concentrations.

[0009] As a further improvement of the present invention, a hydrocyclone is used to apply centrifugal force to the suspension, and a force parallel to the cross-section of the hydrocyclone is applied to the hydrocyclone to generate reciprocating linear acceleration, thereby creating a radial velocity difference between the particles and the fluid.

[0010] As a further improvement of the present invention, the reciprocating linear acceleration includes a first acceleration generated during the forward motion of the hydrocyclone and a second acceleration generated during the return motion, wherein the first acceleration is greater than the second acceleration. More preferably, the first acceleration is 0.02 to 0.1 times the centrifugal acceleration generated by the fluid flow within the hydrocyclone, and the second acceleration is less than 0.02 times the centrifugal acceleration generated by the fluid flow within the hydrocyclone. Here, the forward and return motions are linear reciprocating motions, and further, the ratio of the first acceleration to the second acceleration is not less than 5.

[0011] As a further improvement of the present invention, a hydrocyclone is used to apply centrifugal force to the suspension, and a second force is applied to the hydrocyclone as a whole, causing the hydrocyclone to rotate around an external rotation axis and generate centrifugal acceleration. The angle between the external rotation axis and the axis of the hydrocyclone does not exceed 30 degrees. When the angle is 0 degrees, the external rotation axis is parallel to the axis of the hydrocyclone.

[0012] As a further improvement of the present invention, the centrifugal acceleration of the hydrocyclone is 0.02-0.1 times that of the centrifugal acceleration of the suspension inside the hydrocyclone.

[0013] As a further improvement of the present invention, a hydrocyclone is used to apply centrifugal force to the suspension, and a second force is superimposed on the particles of the suspension to make the particles generate reciprocating tangential acceleration, thereby creating a radial velocity difference between the particles and the fluid; the second angular velocity of the reciprocating tangential acceleration is 0.1-0.4 times the angular velocity of the fluid flow in the hydrocyclone, that is, the second force generates reciprocating tangential acceleration by applying 0.1-0.4 times the angular velocity of the fluid flow to the suspension in the hydrocyclone.

[0014] More preferably, the tangential direction results in a radial velocity gradient caused by the difference in angular velocity between the particles and the fluid, as well as the difference in centrifugal acceleration.

[0015] As a further improvement of the present invention, the particles or some of the particles in the suspension are magnetic particles, and the second force is a magnetic force generated by applying a magnetic field, the magnetic field being parallel to the cross-section of the hydrocyclone. Furthermore, the magnetic field can be constant, or it can vary regularly or irregularly.

[0016] The present invention also discloses a particle separation and classification device, including a hydrocyclone and a Coriolis acceleration application device. The Coriolis acceleration application device applies a second force perpendicular to the centrifugal sedimentation direction of the particles to the hydrocyclone or the particles in the hydrocyclone to generate a secondary external acceleration, causing the particles to generate Coriolis acceleration. The particles are separated and classified using the particle separation and classification method of suspension as described above.

[0017] As a further improvement of the present invention, the Coriolis acceleration application device includes a reciprocating motion drive platform and a reciprocating motion drive mechanism. The hydrocyclone is fixed on the reciprocating motion drive platform, and the reciprocating motion drive mechanism is connected to the reciprocating motion drive platform to drive the reciprocating motion drive platform to perform reciprocating motion.

[0018] As a further improvement of the present invention, the reciprocating motion drive mechanism includes a driver and a drive rod. The hydrocyclone is fixed on a fixed frame, the fixed frame is fixed on a reciprocating motion drive platform, the drive rod is connected to the reciprocating motion drive platform, and the output end of the driver is connected to the drive rod, driving the drive rod to perform linear reciprocating motion, thereby driving the reciprocating motion drive platform and the hydrocyclone to perform reciprocating motion.

[0019] As a further improvement of the present invention, the Coriolis acceleration application device includes a rotating platform and a rotating drive mechanism. The hydrocyclone is fixed on the rotating platform, and the rotating drive mechanism is connected to the rotating platform to drive the rotating platform and the hydrocyclone on it to rotate.

[0020] As a further improvement of the present invention, the rotating platform includes a support base, a rotating part, and a support rod. The support base is connected to the support rod through the rotating part, and the support rod is connected to the hydrocyclone. The rotating drive mechanism drives the rotating part to rotate, thereby driving the hydrocyclone to rotate.

[0021] Furthermore, the support rod is connected to the turntable; the hydrocyclone is mounted on the turntable.

[0022] Furthermore, the turntable has a circular ring structure.

[0023] As a further improvement of the present invention, the Coriolis acceleration application device includes a rotating platform and a rotation drive mechanism. The hydrocyclone is located on the rotating platform, and the rotation axis of the rotating platform is on the same straight line as the axis of rotation. The rotation drive mechanism drives the rotating platform to rotate, thereby driving the hydrocyclone to rotate.

[0024] As a further improvement of the present invention, the particles or some of the particles in the suspension are magnetic particles, the Coriolis acceleration application device includes an external magnetic field generating device, the magnetic field direction of the external magnetic field generating device is perpendicular to the central axis direction of the hydrocyclone, and the external magnetic field generating device includes a permanent magnet block or electromagnet located outside the hydrocyclone.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] First, the technical solution of this invention utilizes the Coriolis effect to generate secondary acceleration of particulate matter in a centrifugal field perpendicular to the particle settling direction within the fluid. The superimposed acceleration causes the particles to move, perpendicular to the radial settling direction of the particles within the fluid. Generally, as particles settle towards the outer wall, the solids concentration of the suspension increases, which increases the effect of hindered settling. That is, particles with higher terminal settling velocities will compress lighter and smaller particles with lower terminal settling velocities, causing friction between particles. However, the technical solution of this invention uses a vertically acting Coriolis force to reduce friction between particles, allowing smaller and lighter particles to be released, thereby improving particle separation and classification performance. Especially under high concentration conditions, it eliminates the adverse effects of hindered particle settling, resulting in better separation and classification effects.

[0027] Secondly, since the Coriolis force is a function of particle mass, particles with higher density or larger diameter will exhibit greater motion perpendicular to the centrifugal settling direction, increasing the classification effect and reducing the concentration of light and small particles in the underflow and heavy particles in the overflow. This further improves the release of smaller or lower density particles from the suspension under obstructed settling conditions, thereby improving the particle size distribution of the suspension within the hydrocyclone and allowing the hydrocyclone to operate at higher solid concentrations. Furthermore, depending on the particle size and density, angular velocity, and rotation radius within the hydrocyclone, the Coriolis acceleration may be greater than the external superimposed acceleration. The overall effect of the superimposed Coriolis acceleration is to improve separation performance and particle classification. Because there are fewer small and light particles in the underflow and fewer large and heavy particles in the overflow, more precise particle size classification can be achieved.

[0028] Third, by employing the technical solution of this invention, the transfer of Coriolis force does not require the injection of additional fluid or additional flushing water, and the solid concentration in the hydrocyclone feed can be higher, avoiding dilution and reducing process water consumption and secondary treatment costs. This method can be applied to any existing hydrocyclone type, whether it is a single unit or a multi-unit hydrocyclone assembly. Attached Figure Description

[0029] Figure 1 This is a motion analysis diagram of particles inside a hydrocyclone according to the first embodiment of the present invention.

[0030] Figure 2 This is a force analysis diagram of particles inside a hydrocyclone according to the first embodiment of the present invention.

[0031] Figure 3 This document presents analysis diagrams of the Coriolis acceleration vector aC of particles within a hydrocyclone according to the first embodiment of the present invention at positions 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315° along the hydrocyclone's rotation path, and curves showing the Coriolis acceleration versus radial position. In these diagrams, a) is the analysis diagram for each position, and b) is the curve showing the functional relationship.

[0032] Figure 4 This is a force analysis diagram of the particles rotating together with the suspension in the hydrocyclone under the condition of applying a secondary centrifugal acceleration (a2=r*ω2) according to the second embodiment of the present invention.

[0033] Figure 5 This is an analysis diagram of the Coriolis acceleration vector aC in the second embodiment of the present invention at positions of 0°, 45°, 90°, 135°, 180°, 225°, 270° and 315° along the rotation path of the hydrocyclone, where a) is the analysis diagram at each position and b) is the function relationship curve.

[0034] Figure 6 This is a force analysis diagram of particles inside a hydrocyclone according to the third embodiment of the present invention, where a) and b) are clockwise and counterclockwise directions, respectively.

[0035] Figure 7 This is a graph showing the functional relationship between the direction of the Coriolis acceleration of particles in the hydrocyclone of the third embodiment of the present invention and the frequency of the superimposed reciprocating tangential acceleration.

[0036] Figure 8 This is a schematic diagram of the particle separation and grading device according to Embodiment 1 of the present invention.

[0037] Figure 9 This is a schematic diagram of the structure of the particle separation and classification device of Embodiment 1 of the present invention, connecting the underflow chute and the overflow chute.

[0038] Figure 10 This is a schematic diagram of the particle separation and grading device according to Embodiment 2 of the present invention.

[0039] Figure 11 This is a schematic diagram of the particle separation and grading device according to Embodiment 3 of the present invention.

[0040] Figure 12 This is a schematic diagram of an improved particle separation and classification device according to Embodiment 3 of the present invention.

[0041] Figure 13 This is a schematic diagram of a second improved structure of the particle separation and classification device of Embodiment 3 of the present invention.

[0042] Figure 14 This is a schematic diagram of the third improved structure of the particle separation and classification device of Embodiment 3 of the present invention.

[0043] Figure 15 This is a schematic diagram of the particle separation and grading device according to Embodiment 4 of the present invention.

[0044] Figure 16 This is a schematic diagram of the rotating drive device of the particle separation and grading apparatus of Embodiment 4 of the present invention.

[0045] Figure 17 This is a schematic diagram of the improved structure of the particle separation and classification device according to Embodiment 4 of the present invention.

[0046] Figure 18 This is a schematic diagram of the magnetic field generated by the external magnetic field generating device in Embodiment 5 of the present invention.

[0047] Figure 19 This is a top view of the hydrocyclone of Embodiment 5 of the present invention.

[0048] Figure 20 This is a schematic diagram of the particle separation and grading device according to Embodiment 5 of the present invention.

[0049] The reference numerals in the figures include:

[0050] 101-Hydrocyclone, 102-Feed inlet, 103-Underflow outlet, 104-Overflow pipe, 105-Reciprocating motion drive platform, 106-Fixed frame, 107-Fixed bracket; 111-Driver, 112-Drive rod; 121-Underflow chute, 122-Overflow chute; 123-Underflow pipe joint, 124-Overflow pipe joint;

[0051] 200-Hydrocyclone, 201-Inlet, 202-Hydrocyclone underflow outlet, 203-Underflow pipe, 204-Overflow pipe; 210-Rotating platform, 211-Support base, 212-Rotating part, 213-Support rod, 214-Turntable; 221-Underflow collection channel;

[0052] 301-Hydrocyclone, 302-Feed inlet, 303-Underflow outlet, 304-Overflow pipe, 305-Rotating platform, 306-Fixed frame, 307-Support, 308-Pivot bearing; 309-Fastening joint, 310-Drive rod, 311-Driver, 312-Hollow shaft, 313-Underflow outlet, 314-Feed pipe; 315-Connecting pipe, 316-Function funnel, 317-Underflow collection funnel, 318-Overflow pipe, 319-Fixed collection channel, 320-Drain pipe;

[0053] 401 - External magnetic field generating device; 402 - Magnetic field strength direction; 403 - Permanent magnet block; 410 - Hydrocyclone; 411 - Feed inlet; 412 - Overflow outlet; 413 - Underflow discharge outlet. Detailed Implementation

[0054] The preferred embodiments of the present invention will be described in further detail below.

[0055] A method for particle separation and classification involves applying centrifugal force to a suspension containing particles and superimposing a second force perpendicular to the centrifugal settling direction onto the particles during centrifugal separation, generating a secondary external acceleration that induces Coriolis acceleration in the particles. The secondary acceleration can be a linear reciprocating acceleration, a constant centrifugal acceleration, or a reciprocating tangential acceleration.

[0056] Specifically, the suspension is treated by a hydrocyclone, and a second force is applied to the entire hydrocyclone. This force is superimposed on the direction perpendicular to the centrifugal settling of the particles, causing the particles to generate Coriolis acceleration.

[0057] The Coriolis force is an inertial force generated when a rotating object moves perpendicular to its axis of rotation. The direction of the Coriolis force depends on the relationship between the motion and the direction of rotation in the rotating system. If the rotation is clockwise, the Coriolis force acts on the left side of the motion; if the rotation is counterclockwise, it acts on the right side.

[0058] The Coriolis force applies acceleration to the rotating particles within the hydrocyclone. Since the force on a particle is the product of acceleration and mass, the velocity of the particle due to acceleration depends on its size or density, thus creating a velocity difference between the particle and the surrounding fluid.

[0059] The Coriolis acceleration aC generated by the superposition of the radial motion of the particles is a function of the product of the angular velocity ω and the superimposed radial velocity vr (aC = 2*ω*vr). Therefore, the ratio of the Coriolis acceleration aC to the external superimposed acceleration is amplified and becomes a function of the angular velocity ω.

[0060] In the first embodiment, a reciprocating linear acceleration parallel to the cross-section of the hydrocyclone is applied to the hydrocyclone, creating a radial velocity difference between the particles and the fluid. That is, a force is applied to the hydrocyclone along the linear direction, causing it to reciprocate along a path parallel to its cross-section. This reciprocating motion can be divided into four parts: acceleration in the linear direction, rapid deceleration followed by a reverse motion, uniform motion, and deceleration followed by a reverse motion. The ratio of the first acceleration generated during the forward motion to the second acceleration generated during the return motion is not less than 5. This technical solution applies positive or negative radial acceleration to the hydrocyclone, generating a velocity difference between the particulate matter and the fluid. This velocity difference is proportional to the mass of the particulate matter, thereby reducing or eliminating friction between particles during sedimentation, achieving better separation while reducing water consumption.

[0061] Furthermore, the first acceleration is 0.02 to 0.1 times the centrifugal acceleration generated by the fluid flow inside the hydrocyclone, and the second acceleration is less than 0.02 times the centrifugal acceleration generated by the fluid flow inside the hydrocyclone.

[0062] like Figure 1 As shown, the particles in the suspension inside the hydrocyclone rotate about axis z with radius r and angular velocity ω. The entire hydrocyclone is subjected to an external acceleration a2 along the y-axis, causing the particles inside the hydrocyclone to generate a secondary velocity v2 along the -y-axis. Under the action of the clockwise angular velocity, a Coriolis acceleration aC is generated along the x-axis. The value of the Coriolis acceleration aC is equal to twice the product of the angular velocity and the secondary velocity, i.e., aC = 2 * ω * v2.

[0063] The forces acting on particles rotating with the suspension inside the hydrocyclone are as follows: Figure 2 As shown, the secondary acceleration a2 is applied in a linear motion parallel to the y-axis, resulting in a secondary velocity v2 for the particle. The radial portion vr of this secondary velocity is related to the Coriolis force. For example, the radial velocity vr and the resulting Coriolis acceleration aC are shown at positions of 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315° along the rotation path.

[0064] When a particle rotates clockwise within a hydrocyclone, the Coriolis velocity component vC lies to the left of the radial velocity component vr. At 0° and 180°, the Coriolis acceleration is at its maximum when the radial velocity vector vr is parallel to the Y-axis. At 90° and 270°, the secondary velocity does not cause radial displacement of the particle, and therefore no Coriolis acceleration is observed.

[0065] Figure 3 The Coriolis acceleration vector aC is given by superimposed quadratic linear acceleration at the positions 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315° along the rotation path of the hydrocyclone. The direction of the Coriolis acceleration depends on the particle's position on the rotation path. The maximum Coriolis acceleration is located at 0° and 180°. The zero point is located at 90° and 270°. The direction of the Coriolis acceleration reverses twice during one rotation at the 90° and 270° positions. When plotted graphically, the function of Coriolis acceleration versus radial position is a sine curve, with maximum values ​​at 0° and 180° and inflection points at 90° and 270°.

[0066] Furthermore, since the superimposed external acceleration is applied intermittently with the reciprocating motion, the Coriolis acceleration also varies with time. The advantage of linear acceleration is that the Coriolis force changes at a higher frequency under moderate intensity. This method is suitable for larger particles and less regular, non-spherical particles.

[0067] Example 1

[0068] A schematic diagram of the apparatus for particle separation and classification, which implements the first embodiment described above, is shown below. Figure 8 As shown, it includes a hydrocyclone 101 and a Coriolis acceleration application device, wherein the Coriolis acceleration application device is a device for driving the hydrocyclone 101 to perform reciprocating motion.

[0069] The hydrocyclone 101 includes a feed inlet 102, an underflow outlet 103, and an overflow pipe 104. The hydrocyclone 101 is fixed to a fixed frame 106, specifically via a fixed bracket 107. The fixed frame 106 is fixed to a reciprocating motion drive platform 105. The reciprocating motion drive platform 105 is fixed vertically and can only move horizontally.

[0070] The reciprocating motion drive device performs reciprocating motion on the reciprocating motion drive platform 105. The reciprocating motion drive device includes a driver 111 and a drive rod 112. The drive rod 112 is connected to the reciprocating motion drive platform 106. Further, the driver 201 includes a motor equipped with a gearbox. The output end of the driver 111 is connected to the drive rod 112, driving the drive rod 112 to perform linear reciprocating motion, and transmitting the reciprocating motion to the hydrocyclone 101 through the reciprocating motion drive platform 105.

[0071] Furthermore, such as Figure 9 As shown, an underflow chute 121 is provided below the underflow outlet 103 of the hydrocyclone 101. The underflow of the hydrocyclone 101 is collected through the underflow chute 121. The outlet of the overflow pipe 104 of the hydrocyclone 101 faces the overflow chute 122, and the overflow is collected in the overflow chute 302. Furthermore, the underflow chute 301 and the overflow chute 122 can be fixed to the external frame and are connected to external pipelines through the underflow pipe joint 123 and the overflow pipe joint 124, respectively.

[0072] Example 2

[0073] Based on Example 1, this example can be further extended, such as... Figure 10 As shown, multiple hydrocyclones 101 can be fixed on the reciprocating motion drive platform 105. Each hydrocyclone 101 is fixed to the reciprocating motion drive platform 105 by a fixing frame 106. Multiple hydrocyclones 101 can be driven to perform reciprocating motion by a single driver 111. In this embodiment, the superimposed Coriolis motion improves the particle separation and classification performance of each hydrocyclone 101.

[0074] In the second embodiment, a second force is applied to the hydrocyclone as a whole, causing it to rotate around an external axis and generate centrifugal acceleration. The angle between the external axis and the axis of the hydrocyclone does not exceed 30 degrees. When the angle is 0 degrees, the external axis is parallel to the axis of the hydrocyclone. More preferably, the centrifugal acceleration of the hydrocyclone is 0.02-0.1 times the centrifugal acceleration of the suspension inside the hydrocyclone. In this scheme, the Coriolis force acts as a superposition with the centrifugal acceleration.

[0075] In this implementation, the high acceleration of centrifugal motion creates a radial velocity gradient between the particles and the fluid. The difference in radial velocity alters the centrifugal acceleration, leading to a radial velocity gradient between particles of different sizes or densities. The resulting Coriolis acceleration is a function of the product of the radial velocity and the angular velocity. For a clockwise circulating hydrocyclone, the corresponding Coriolis acceleration is perpendicular to the left side of the radial velocity, while for a counter-clockwise circulation, it is perpendicular to the right side of the radial velocity.

[0076] Coriolis motion causes pulsating lateral motion as particles settle toward the outer wall. Since the Coriolis force is a function of particle mass and shape, a force gradient is generated between particles of different diameters and densities, thus overcoming the static friction between contacting particles. The result is the release of lighter and smaller particles from the higher concentration suspension into the overflow of the hydrocyclone, thereby overcoming what is commonly referred to as obstructed settling.

[0077] Figure 4 This shows the forces acting on particles rotating with the suspension within a hydrocyclone under a secondary centrifugal acceleration (a2 = r * ω2). The secondary centrifugal acceleration is generated by the rotation of the hydrocyclone about its axis z2, with the hydrocyclone's rotation axis z1 approximately parallel to the secondary rotation axis z2. The superimposed secondary centrifugal acceleration produces a secondary velocity v2 radially relative to the axis z2.

[0078] The second-order velocity vector v2 can be divided into a radial vector vr along the hydrocyclone axis z1 and a vector vr perpendicular to it. Only the velocity vector vr is related to the Coriolis effect. For example, the radial velocity vector vr and the resulting Coriolis acceleration aC are located at 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315° along the rotation path, respectively. When rotating clockwise within the hydrocyclone, the direction of the Coriolis acceleration aC is to the left of the radial velocity vector vr.

[0079] Figure 5 The direction of the Coriolis acceleration vector aC is shown at 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315° along the hydrocyclone's rotation path, with secondary centrifugal acceleration superimposed. The direction of the Coriolis acceleration depends on the particle's position along the rotation path.

[0080] The Coriolis acceleration reaches its maximum at 90° and 270°, where the second-order velocity v2 is parallel to the hydrocyclone axis x. These positions are the intersections of the particle's orbit and the external rotating orbit. At these intersections, the direction of the Coriolis acceleration reverses twice during one revolution.

[0081] The advantage of secondary centrifugal acceleration is that the Coriolis force is greater and the portion of the Coriolis acceleration reversal is shorter. This method is suitable for smaller particles or particles with more regular, more spherical shapes.

[0082] In a specific implementation, the hydrocyclone or hydrocyclone assembly can be vertically mounted on a rotating platform, which is then driven to rotate clockwise or counterclockwise by a drive mechanism. Depending on the position of the particles within the hydrocyclone and their circulation direction, positive or negative radial acceleration is applied, making the velocity difference between the particles and the fluid proportional to the particle mass. This radial superposition generates a Coriolis force perpendicular to the settling direction, which can reduce or eliminate static friction between particles along the settling path, thereby achieving better separation and lower process water consumption. See Example 3 for details.

[0083] Example 3

[0084] A schematic diagram of the apparatus for implementing the second implementation scheme and performing particle separation and classification is shown below. Figure 11 As shown, it includes a hydrocyclone 200 and a Coriolis acceleration application device, wherein the Coriolis acceleration application device drives the hydrocyclone 201 to rotate around an external rotation axis to generate centrifugal acceleration.

[0085] The hydrocyclone 200 is located on a rotating platform 210, which includes a support base 211, a rotating part 212, a support rod 213, and a turntable 214. The support base 211 is connected to the support rod 213 through the rotating part 212, and the support rod 213 is connected to the turntable 214. The hydrocyclone 201 is mounted on the turntable 214. When the rotating platform 210 rotates, it drives the rotating part 212 to rotate, which in turn drives the turntable 214 to rotate, thereby causing the hydrocyclone 200 to rotate clockwise or counterclockwise, so that the high-speed moving particles inside the hydrocyclone 200 are subjected to the Coriolis force.

[0086] like Figure 11 As shown, the hydrocyclone 200 has an inlet 201, an underflow outlet 202, and an overflow pipe 204 connected to an overflow outlet. The underflow outlet 202 guides high-concentration large particles to the underflow collection channel 221 through the underflow pipe 203. The outlet of the overflow pipe 204 faces the overflow collection channel 222, and the overflow pipe 204 guides low-concentration fine particles to the overflow collection channel 222. The hydrocyclone 200 can be a single hydrocyclone or a group of hydrocyclones in different combinations. This embodiment shows two hydrocyclone groups.

[0087] The rotating platform 210 can have various structural forms. For example... Figure 12As shown, this is a compact Coriolis force-enhanced external centrifugal accelerator hydrocyclone device. The rotating disk 214 shown is a hollow annular shape. The overflow pipes 204 of the hydrocyclone 2 are all located near the center of the plane of the rotating disk 214. The central axes of the overflow collection channel 222 and the underflow collection channel 221 are collinear with the axis of the rotating disk 214. In this embodiment, the components are compactly designed and occupy little space. To more clearly illustrate the structural relationship, the overflow collection channel 222 is arranged above the rotating disk 214, and the underflow collection channel 221 is arranged below the rotating disk 214. In actual implementation, it is feasible to arrange both the overflow collection channel 222 and the underflow collection channel 221 above or below the rotating disk 214, or simultaneously on the outer side of the rotating disk 214 to form an annular structure.

[0088] Furthermore, such as Figure 13 As shown, the turntable 214 can be a complete disc structure, or other regular polygonal or polygonal ring structures that can be stably fixed and rotated can be selected according to the number of hydrocyclones installed.

[0089] Furthermore, such as Figure 14 As shown, when the hydrocyclone 200 is small and light, the structure of the rotating platform 210 can be simplified, that is, the turntable 214 can be removed and the hydrocyclone can be directly mounted on the support rod 213.

[0090] In the third implementation, a second force is superimposed on the hydrocyclone to cause the particles to experience superimposed reciprocating tangential acceleration. The high acceleration of forward motion creates a tangential velocity gradient between the particles and the fluid. The difference in tangential velocity alters the centrifugal acceleration, which in turn leads to a radial velocity gradient between particles of different sizes or densities. This results in Coriolis acceleration being a function of the product of radial velocity and angular velocity. The superimposed tangential velocity difference between the particles and the fluid leads to a difference in radial centrifugal acceleration and radial velocity gradient. The corresponding Coriolis acceleration depends on the tangential velocity gradient and the particle orbital radius.

[0091] Furthermore, the second angular velocity of the reciprocating tangential acceleration is 0.1-0.4 times the normal angular velocity of the fluid inside the hydrocyclone.

[0092] Forces acting on particles rotating in a suspension, such as Figure 6 As shown, the suspension exhibits superimposed reciprocating tangential accelerations. The direction of the Coriolis acceleration is independent of the particle's position on its rotational path.

[0093] For the case where the hydrocyclone rotates clockwise and the superimposed tangential velocities are in the same direction, the Coriolis velocity component vC is negative and parallel to the x-axis; for the case where the hydrocyclone rotates clockwise and the superimposed tangential velocities are in opposite directions, the Coriolis velocity component vC is positive and parallel to the x-axis.

[0094] The functional relationship between the direction of the Coriolis acceleration and the frequency of the superimposed reciprocating tangential acceleration is as follows: Figure 7 As shown, the direction of the Coriolis acceleration depends only on the direction of the external tangential acceleration and is the same at all points along the particle's rotation path. The direction of the Coriolis velocity component varies sinusoidally with the direction of the tangential acceleration, and is zero where the direction of the external acceleration changes. Because the Coriolis velocity is a function of the radius, tangential reciprocating acceleration is most suitable for hydrocyclones with larger diameters.

[0095] In this specific implementation, a traditional hydrocyclone is vertically mounted on a rotating platform, with the hydrocyclone's centerline located on the platform's rotation axis. The rotating platform reciprocates, experiencing greater acceleration when moving forward and less acceleration when moving backward. The platform's forward direction is the same as the internal circulation direction of the hydrocyclone. If the hydrocyclone flows clockwise, the platform's forward direction is clockwise. If the hydrocyclone flows counterclockwise, the platform's forward direction is counterclockwise.

[0096] As the rotating platform accelerates forward, the tangential motion of the particles is opposite to the direction of the circulating flow, while the radial velocity is directed towards the axis of rotation. For a clockwise circulating hydrocyclone, the corresponding Coriolis acceleration is perpendicular to the left side of the radial velocity, while for a counterclockwise circulation, it is perpendicular to the right side of the radial velocity. Coriolis motion causes pulsating lateral motion as particles settle towards the outer wall. Since the Coriolis force is a function of particle mass and shape, a force gradient is generated between particles of different diameters and densities, thus overcoming the static friction between contacting particles. The result is the release of lighter and smaller particles from the higher concentration suspension into the overflow of the hydrocyclone, thereby overcoming the commonly referred to hindered settling effect.

[0097] Example 4

[0098] The apparatus for implementing the third embodiment and performing particle separation and classification includes a hydrocyclone 301 and a Coriolis acceleration application device, wherein the Coriolis acceleration application device is a rotary drive device that drives the hydrocyclone 301 to rotate and generate tangential acceleration.

[0099] like Figure 15 As shown, the hydrocyclone 301 is provided with a feed inlet 302, an underflow outlet 303 and an overflow pipe 304. The hydrocyclone 301 is fixed on a fixed frame 306 by a bracket 307. The fixed frame 306 is fixed on a rotating platform 305. The rotating platform 305 is mounted on a pivot bearing 308.

[0100] like Figure 16The rotary drive device connected to the rotary platform 305 is shown, including a fastening joint 309, a drive rod 310, and a driver 311. The rotary platform 305 is fixed on a hollow shaft 312. The driver 311 drives the rotary platform 305 to rotate via the drive rod 310. The hollow shaft 312 rotates within a pivot bearing 308. A bottom flow outlet 313 is provided at the bottom of the pivot bearing 308, forming an angular space. The feed pipe 314 is located at the center of the bottom flow outlet 313.

[0101] Example 5

[0102] Based on Example 4, the main improvement in this example lies in the pipe connection. For example... Figure 17 The diagram shows the piping connection of the hydrocyclone 301, which is mounted on a rotating platform 305 above a pivot bearing 308. The fixed frame 306 is a hollow structure. The feed pipe 314 enters from below the pivot bearing 308 through a hollow shaft 312 and is connected to the fixed frame 306 on the rotating platform 305 via a connecting pipe 315, communicating with its hollow part. One end of the feed pipe 314 is connected to the top of the fixed frame 306, and the other end is connected to the inlet of the hydrocyclone 301.

[0103] The underflow from the underflow outlet 303 flows into the funnel 316, passes through the annular space between the hollow shaft 312 and the feed pipe 314, and is discharged into the underflow collection funnel 317. The overflow pipe 318 extends to the fixed collection channel 319, and the overflow is discharged through the drain pipe 320.

[0104] In the fourth implementation, the Coriolis force is applied using magnetic force. This method is used for the separation of magnetic particles (such as magnetite), or for particles that are partially magnetic. Specifically, a magnetic field parallel to the cross-section of the hydrocyclone is applied, meaning the direction of the magnetic field is perpendicular to the central axis of the hydrocyclone. The external magnetic field can superimpose linear acceleration onto the magnetic particles, causing the magnetic particles (such as magnetite) to be accelerated by the Coriolis effect. This generates magnetic force and second-order tangential acceleration on the magnetic particles, thus optimizing the particle separation and classification performance in the hydrocyclone by utilizing the Coriolis effect. The magnetic field can be constant, or it can vary regularly or irregularly.

[0105] In this implementation scheme, by adding an external magnetic field, the magnetic particles in the hydrocyclone are affected by magnetic force. The magnetic particles, under the influence of the magnetic field, undergo a change in radial motion. Being in a rotating state and experiencing this change in radial motion, the Coriolis effect is generated, resulting in particles with superimposed linear acceleration exhibiting motion perpendicular to radial settling. Furthermore, the Coriolis force acting on the particles due to the magnetic force reduces the static friction between particles during settling, allowing smaller and lighter particles to enter the overflow of the hydrocyclone more effectively, while larger particles enter the underflow more frequently.

[0106] In traditional hydrocyclones, small and large particles often collide and agglomerate during settling. This technical solution modifies the traditional hydrocyclone to overcome the static friction between large and small particles using the Coriolis force, thus preventing particle agglomeration. This allows large and small particles to separate, with more small particles being discharged through the top overflow outlet, while large particles can be smoothly discharged through the bottom discharge outlet, optimizing the overall separation effect.

[0107] For a hydrocyclone with clockwise circulation, the corresponding Coriolis acceleration is perpendicular to the left side of the radial velocity, while for a counterclockwise circulation, it is perpendicular to the right side of the radial velocity.

[0108] Because the Coriolis force is a function of mass, particles with higher density or larger diameter are more significantly affected, thus improving the static friction between particles and resulting in better separation and classification.

[0109] Example 6

[0110] The apparatus for implementing the third embodiment and performing particle separation and classification includes a hydrocyclone and a Coriolis acceleration application device, wherein the Coriolis acceleration application device is an external magnetic field generating device 101.

[0111] like Figure 18 As shown, the external magnetic field generating device 401 can be two permanent magnet blocks or non-permanent electromagnetic blocks. The magnetic field strength direction 402 is parallel to the x-axis and parallel to the feeding direction of the feed port 411 of the hydrocyclone 410, and perpendicular to the rotation axis z-axis of the hydrocyclone.

[0112] A top view of a hydrocyclone is shown below. Figure 19 As shown in the figure, the particle moves about the z-axis with radius r and angular velocity ω. Due to the presence of an external magnetic field, the magnetic particle experiences a magnetic force, generating a secondary acceleration a2 along the -y-axis, where vr is the fluid velocity in the +y direction. When the angular velocity ω is clockwise, a Coriolis acceleration ac is generated along the -x-axis.

[0113] like Figure 20The diagram shows a schematic of an external magnetic field for a hydrocyclone. The hydrocyclone 410 is provided with an inlet 411, an overflow 412, and an underflow discharge 412. The external magnetic field generating device 401 includes two permanent magnet blocks 403, or it can be a non-permanent electromagnetic block.

[0114] Two permanent magnet blocks 403 are vertically installed on the outer wall of the separation zone of the hydrocyclone, having no impact on the operation of the concentration zone. Furthermore, when the permanent magnet blocks 403 are parallel to the axis of the hydrocyclone 410, the longitudinal length of the permanent magnet blocks 403 is no greater than the length of the straight section of the hydrocyclone 410, resulting in a magnetic field perpendicular to the rotation axis inside the hydrocyclone 410. During operation of the hydrocyclone 410, the magnetic particles are attracted by the magnetic field, generating a downward acceleration. Due to the magnetic force, the radial motion of the magnetic particles changes, generating a Coriolis force. If the magnetic particles rotate counterclockwise inside the hydrocyclone, the resulting Coriolis acceleration acts on the right side of the particles. This Coriolis acceleration is related to the particle mass; by utilizing mass differences, particles of different sizes are separated.

[0115] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A method for particle separation and classification, characterized in that: Centrifugal force is applied to a suspension containing particles, and a second force perpendicular to the centrifugal settling direction is superimposed on the particles during centrifugal separation, generating a secondary external acceleration that causes the particles to undergo Coriolis acceleration. A hydrocyclone is used to apply centrifugal force to the suspension, and a force parallel to the cross-section of the hydrocyclone is applied to the hydrocyclone to generate reciprocating linear acceleration, thereby creating a radial velocity difference between the particles and the fluid. The reciprocating linear acceleration includes a first acceleration generated during the forward motion of the hydrocyclone and a second acceleration generated during the return motion; the ratio of the first acceleration to the second acceleration is not less than 5; the first acceleration is 0.02 to 0.1 times the centrifugal acceleration generated by the fluid flow inside the hydrocyclone, and the second acceleration is less than 0.02 times the centrifugal acceleration generated by the fluid flow inside the hydrocyclone.

2. A method for particle separation and classification, characterized in that: Centrifugal force is applied to a suspension containing particles, and a second force perpendicular to the centrifugal settling direction is superimposed on the particles during centrifugal separation, generating a secondary external acceleration that causes the particles to undergo Coriolis acceleration. A hydrocyclone is used to apply centrifugal force to the suspension, and a second force is applied to the hydrocyclone as a whole to make the hydrocyclone rotate around an external rotation axis to generate centrifugal acceleration. The angle between the external rotation axis and the axis of the hydrocyclone does not exceed 30 degrees. The centrifugal acceleration of the hydrocyclone is 0.02-0.1 times that of the centrifugal acceleration of the suspension inside the hydrocyclone.

3. A method for particle separation and classification, characterized in that: Centrifugal force is applied to a suspension containing particles, and a second force perpendicular to the centrifugal settling direction is superimposed on the particles during centrifugal separation, generating a secondary external acceleration that causes the particles to undergo Coriolis acceleration. A hydrocyclone is used to apply centrifugal force to the suspension, and a second force is superimposed on the particles of the suspension to make the particles generate reciprocating tangential acceleration, thereby creating a radial velocity difference between the particles and the fluid; the second angular velocity of the reciprocating tangential acceleration is 0.1-0.4 times the angular velocity of the fluid flow in the hydrocyclone.

4. A particle separation and classification device, characterized in that: It includes a hydrocyclone and a Coriolis acceleration application device, wherein the Coriolis acceleration application device applies a second force perpendicular to the centrifugal settling direction of the particles to the hydrocyclone or the particles within the hydrocyclone, and the particles are separated and classified using the particle separation and classification method as described in any one of claims 1 to 3.

5. The particle separation and classification device according to claim 4, characterized in that: The Coriolis acceleration application device includes a reciprocating motion drive platform and a reciprocating motion drive mechanism. The hydrocyclone is fixed on the reciprocating motion drive platform, and the reciprocating motion drive mechanism is connected to the reciprocating motion drive platform to drive the reciprocating motion drive platform to perform reciprocating motion. Alternatively, the Coriolis acceleration application device may include a rotating platform and a rotating drive mechanism, wherein the hydrocyclone is fixed on the rotating platform and the rotating drive mechanism is connected to the rotating platform to drive the rotating platform and the hydrocyclone on it to rotate. Alternatively, the Coriolis acceleration application device may include a rotating platform and a rotation drive mechanism, wherein the hydrocyclone is located on the rotating platform and the rotation axis of the rotating platform is on the same straight line as the axis of rotation, and the rotation drive mechanism drives the rotating platform to rotate, thereby causing the hydrocyclone to rotate.

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