Separation devices and fluid devices

Abstract

The present invention provides a separation device that allows for easy separation of fine particles concentrated in the center of a flow path, and a fluid device having such a separation device that can easily concentrate fine particles in a liquid. [Solution] A separation device connected to a flow channel for a liquid, which separates the liquid into a first liquid flowing through the center of the flow channel and a second liquid flowing along the inner wall of the flow channel, comprising a device body having a through hole and an exterior member housing the device body, the exterior member being spaced apart from the device body and having a top plate with an inlet to which the flow channel is connected, the through hole opening to the surface of the device body opposite to the top plate and being a main flow channel for the first liquid, the space between the top plate and the opposing surface being a secondary flow channel for the second liquid, the opening of the through hole overlapping with the inlet in the central axis direction of the inlet, the opening diameter of the inlet being larger than the opening diameter of the through hole on the opposing surface and smaller than the maximum outer diameter of the device body on the opposing surface.

Description

Technical Field

[0001] The present invention relates to a separation device and a fluid device.

Background Art

[0002] Conventionally, a fluid device for acoustically focusing fine particles in a fluid (liquid) is known (for example, see Patent Document 1). The fluid device described in Patent Document 1 includes a flow path member through which a fluid flows and an ultrasonic element provided in the flow path. By applying ultrasonic vibration to the fluid flowing in the flow path from the ultrasonic element, fine particles dispersed in the fluid can be converged (concentrated) near the center of the flow path.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Non-Patent Documents

[0004]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Using a fluid device such as the one described in Patent Document 1, after concentrating the fine particles in the center of the flow path, it is possible to concentrate the fine particles by separating the fluid flowing through the flow path into (1) the central portion of the flow path where the fine particles are concentrated and (2) the peripheral portion of the flow path where the fine particles have been reduced. In such cases, conventionally, a configuration is known in which an inner tube is inserted into the central portion of the flow path to create a double-tube flow path (separation section) downstream of the configuration that concentrates the fine particles, and the concentrated fine particles are separated by guiding portion (1) into the inner tube.

[0006] However, in a separation unit using a double tube as described above, if the central axes of the inner and outer tubes are misaligned, there is a risk that (1) will leak into the outer tube. In a separation unit with this configuration, the assembly precision easily affects the efficiency of separating fine particles, and improvement was needed.

[0007] This invention has been made in view of these circumstances, and aims to provide a separation device that can easily separate fine particles concentrated in the center of a flow path. It also aims to provide a fluid device having such a separation device that can easily concentrate fine particles in a liquid. [Means for solving the problem]

[0008] To solve the above problems, one aspect of the present invention includes the following aspects.

[0009] [1] A separation device connected to a flow channel for a liquid, which separates the liquid into a first liquid flowing through the center of the flow channel and a second liquid flowing along the inner wall of the flow channel, comprising: a device body having a through hole; and an exterior member housing the device body, wherein the exterior member is spaced apart from the device body and has a top plate with an inlet to which the flow channel is connected; the through hole opens to the surface of the device body opposite to the top plate and is a main flow channel for the first liquid; the space between the top plate and the opposing surface is a secondary flow channel for the second liquid; the opening of the through hole overlaps with the inlet in the central axis direction of the inlet; the opening diameter of the inlet is larger than the opening diameter of the through hole on the opposing surface and smaller than the maximum outer diameter of the device body on the opposing surface.

[0010] [2] The separation device according to [1], wherein the through hole extends in the direction of the central axis.

[0011] [3] The separation device according to [2], wherein the opposing surface is annular, the opening is circular, and the center position of the opposing surface coincides with the center position of the opening.

[0012] [4] The separation device according to any one of [1] to [3], wherein the opposing surface and the inner surface of the top plate are parallel.

[0013] [5] The separation device according to any one of [1] to [4], wherein the exterior member has a bottom plate that faces the top plate and supports the main body of the device, and the bottom plate has an outlet that communicates with the through hole and discharges the first liquid.

[0014] [6] The separation device according to any one of the items [1] to [5], comprising a plurality of device bodies and an exterior member that commonly houses the plurality of device bodies, wherein the top plate has a plurality of inlets that each overlap with the through holes of the plurality of device bodies.

[0015] [7] The separation device according to [6], wherein the separation device has a confluence section that communicates with a plurality of through holes of the device body on the downstream side.

[0016] [8] A fluid device comprising a flow path for flowing a liquid containing particles, a converging portion for converging the particles to the center of the flow path while flowing the liquid, and a separation device according to any one of [1] to [7] connected downstream of the converging portion for separating the liquid into the first liquid and the second liquid.

[0017] [9] The converging portion has a flow path member having a flow path through which the liquid flows as the flow path, and a vibrating portion for vibrating the flow path member. The vibrating portion has a vibrating plate to which the flow path member is attached on a main surface, and a vibrator for vibrating the vibrating plate in the thickness direction of the vibrating plate. The fluid device according to [8].

Advantages of the Invention

[0018] According to the present invention, it is possible to provide a separation device capable of easily separating fine particles concentrated in the center of the flow path. Further, it is possible to provide a fluid device having such a separation device and capable of easily concentrating fine particles in a liquid.

Brief Description of the Drawings

[0019] [Figure 1] FIG. 1 is an explanatory view showing a separation device and a fluid device according to the first embodiment. [Figure 2] FIG. 2 is a cross-sectional view of the converging portion 20A. [Figure 3] FIG. 3 is a perspective view showing a separation device 40A according to an embodiment. [Figure 4] FIG. 4 is a cross-sectional view taken along the line VI-VI of FIG. [Figure 5] FIG. 5 is an explanatory view for explaining the function of the separation device 40A. [Figure 6] FIG. 6 is a schematic perspective view showing a separation device and a fluid device according to the second embodiment. [Figure 7] FIG. 7 is a cross-sectional view taken along the line VII-VII of FIG. [Figure 8]FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG. 6, as viewed in the direction of the arrow. [Figure 9] FIG. 9 is a block diagram for explaining the configuration of the control unit 30. [Figure 10] FIG. 10 is an explanatory diagram for explaining the composite waveform.

Embodiments for Carrying Out the Invention

[0020] [First Embodiment] . In all the following drawings, for the sake of easy viewing of the drawings, the dimensions, ratios, etc. of each component are appropriately made different.

[0021] 《Fluid Device, Separation Device》 FIG. 1 is an explanatory diagram showing the separation device and the fluid device of the present embodiment. As shown in FIG. 1, the fluid device 100A of the present embodiment includes a supply unit 10, a converging unit 20A, a control unit 30, and the separation device 40A of the present embodiment. The fluid device 100A has a function of converging the fine particles P in a cross section orthogonal to the flow direction of the liquid L while flowing the liquid L containing the fine particles P, and separating the liquid L into a first liquid L1 and a second liquid L2.

[0022] [Supply Unit] The supply unit 10 stores the liquid L containing the fine particles P and supplies it to the downstream side. The supply unit 10 includes a storage unit 11, a pipe 12, and a pump 13.

[0023] The storage unit 11 is a container for storing the liquid L. Although only one storage unit 11 is shown in FIG. 1, the present invention is not limited to this, and a plurality of storage units 11 may be prepared so that the discharge source can be switched according to the remaining amount of the liquid L.

[0024] The piping 12 is a pipeline through which the liquid L discharged from the storage section 11 flows. The piping 12 has a main pipe 120 with one end connected to the storage section 11, branch pipes 121, 122, and 123 that branch off from the main pipe 120 downstream of the main pipe 120, and a branching section 125 that branches the liquid L from the main pipe 120 to the branch pipes 121, 122, and 123. In this embodiment, the branching section 125 is configured to branch into three branch pipes 121, 122, and 123, but it is not limited to this configuration; it may also be configured to branch into two, or into four or more.

[0025] The other end of pipe 12 (the other end of branch pipes 121, 122, and 123) is connected to the convergence section 20A.

[0026] The pump 13 is installed within the flow path of the piping 12 and causes the liquid L in the piping 12 to flow downstream. Preferably, the pump 13 has a structure that prevents blockage by fine particles P contained in the liquid L. Such a pump 13 can preferably be a tube pump or a diaphragm pump.

[0027] [Convergence section] The convergence section 20A has a flow channel for the liquid L supplied from the supply section 10, and has the function of convergeding fine particles P in the cross-section of the flow channel while the liquid L is flowing. The "cross-section of the flow channel" refers to the cross-section in a virtual plane perpendicular to the direction of extension of the flow channel.

[0028] The converging section 20A includes a flow path member 21 and a vibrating section 22.

[0029] (Flow channel member) The flow channel member 21 has a flow channel through which the liquid L flows. In the fluid device 100A of this embodiment, the flow channel member 21 has three members: a first flow channel member 211, a second flow channel member 212, and a third flow channel member 213. The first flow channel member 211 has a first flow channel 211a through which the liquid L flows. Similarly, the second flow channel member 212 has a second flow channel 212a, and the third flow channel member 213 has a third flow channel 213a.

[0030] In other words, in the fluid device 100A, three flow channels are connected in parallel. In Figure 1, the first flow channel member 211, the second flow channel member 212, and the third flow channel member 213 are arranged in approximately parallel directions.

[0031] Figure 2 is a cross-sectional view of the convergence section 20A. As shown in Figure 2, the first flow channel member 211 and the second flow channel member 212 of the flow channel member 21 have circular cross-sectional shapes for each flow channel (first flow channel 211a and second flow channel 212a). In the third flow channel member 213 (not shown), the cross-sectional shape of the third flow channel 213a is also preferably circular.

[0032] (Vibrating part) The vibrating unit 22 is provided in common to each of the parallel-connected flow paths and supplies ultrasonic vibrations to each flow path by vibrating the flow path member 21. The vibrating unit 22 has a diaphragm 221 and a transducer 222.

[0033] The diaphragm 221 is a plate-shaped member that exhibits a rectangular shape when viewed from the direction normal to the diaphragm 221, and the flow channel member 21 is attached to the main surface 221a. The "main surface" is the surface of the diaphragm 221 that faces the outside of the vibrating section 22 and is the surface that is exposed in the field of view from the normal direction.

[0034] A flow channel member 21 is attached to the diaphragm 221 via an adhesive layer 223. In the field of view normal to the diaphragm 221, the diaphragm 221 overlaps with a portion of the flow channel member 21. A relatively longer length of the portion where the diaphragm 221 and the flow channel member 21 are in contact (the length of the flow channel member 21 in contact with the diaphragm 221 in the flow direction) is preferable as it promotes acoustic convergence. For example, when using a SUS pipe with an inner diameter of about 1 mm as the flow channel member, it is preferable that the diaphragm 221 and the flow channel member 21 (SUS pipe) are in contact for 10 mm or more, and more preferable that they are in contact for 40 mm or more.

[0035] The vibrator 222 vibrates the diaphragm 221 in the thickness direction of the diaphragm 221. As a result, the vibrating unit 22 can vibrate the flow channel member 21 in the thickness direction of the diaphragm 221.

[0036] The transducer 222 can use any known ultrasonic transducer that converts high-frequency power into ultrasonic vibrations. Two types of ultrasonic transducers are known: electrostrictive transducers and magnetostrictive transducers. However, for transducer 222, an electrostrictive transducer capable of generating relatively high-frequency ultrasonic vibrations is preferred. Examples of electrostrictive transducers include piezoelectric elements using lead zirconate titanate (PZT) and transducers using lithium niobate (LiNbO3).

[0037] Similar to known fluid devices based on the principle of acoustic convergence, in the fluid device 100A, the vibrator 222 (vibrating part 22) emits ultrasonic vibrations that generate standing waves W in the flow path, as the vibration state of the vibrating part 22 is controlled by the control unit 30, which will be described later. As a result, an acoustic radiation force F is applied to the fine particles P dispersed in the liquid L within the flow path member 21, directed from the inner wall of the flow path towards the center of the flow path, causing the fine particles P to converge (acoustic convergence) near the center of the cross-section of the flow path.

[0038] In this case, in the flow channel member 21, which has a circular flow channel shape, standing waves W are generated isotropically in the cross-sections of the first flow channel 211a, the second flow channel 212a, and the third flow channel 213a. Therefore, in the flow channel member 21, it is easy to converge the fine particles P towards the center of the flow channel.

[0039] The "ultrasonic vibration that generates a standing wave W in the flow path" can be determined theoretically or experimentally through preliminary experiments.

[0040] [Control Unit] The control unit 30 controls the operation of the focusing unit 20A. Specifically, the control unit 30 controls the operation of the vibrator 222 of the vibrating unit 22 by creating a drive signal to operate the vibrator 222 and supplying it to the vibrator 222. As a result, the acoustic focusing described above occurs in the focusing unit 20A, and the fine particles P dispersed in the liquid L are focused. The control unit 30 may also control the pump 13 of the supply unit 10.

[0041] [Separation device] Figure 3 is a perspective view showing the separation device 40A of this embodiment. Figure 4 is a cross-sectional view taken along the line segment VI-VI in Figure 3. The separation device 40A is connected to a flow path (flow path member 21) through which the liquid L flows. The separation device 40A separates the liquid L flowing within the flow path member 21 into a first liquid L1 flowing in the center of the axial cross-section of the flow path and a second liquid L2 flowing along the inner wall side of the flow path.

[0042] Due to the function of the convergence section 20A described above, the fine particles P converge in the first liquid L1 flowing through the center of the flow path. Therefore, the separation device 40A can separate the liquid L into the first liquid L1, which contains a large amount of fine particles P, and the second liquid L2, which contains relatively fewer fine particles P than the first liquid L1.

[0043] As shown in Figures 3 and 4, the separation device 40A has a main channel FP1 for flowing the first liquid L1 and a sub-channel FP2 for flowing the second liquid L2. The main channel FP1 overlaps with the channel in the field of view in the direction of the central axis C1 of the inlet 40a to which the channel 21a (channel member 21) is connected. The sub-channel FP2 is provided in a direction intersecting the main channel FP1.

[0044] The separation device 40A has a device body 41 and an exterior member 42.

[0045] (Main unit of the device) The device body 41 is a cylindrical member with both ends open. One end of the device body 41 shown in the figure, the opposing surface 41x facing inward with the inner surface of the outer casing member 42, is an annular plane in the field of view in the direction of the central axis C1. The side surface 41y of the device body 41 may be parallel to the central axis C2 of the device body 41, or it may intersect the central axis C1 at an angle. That is, the device body 41 may be a cylindrical member as shown in Figure 3, or it may be a frustoconical member.

[0046] The device body 41 has a through hole 41a. The through hole 41a is the main flow path FP1 of the separation device 40A and has an opening A that opens to the opposing surface 41x. In the field of view in the direction of the central axis C1, the opening A overlaps with the flow path 21a in the flow path member 21. The device body 41 is a straight tubular member having a through hole 41a extending in the direction of the central axis C1.

[0047] Aperture A is circular in the field of view along the central axis C1, and the center of aperture A coincides with the center of the opposing surface 41x.

[0048] (Exterior components) The exterior member 42 is a member that houses the device body 41. The exterior member 42 shown in Figures 3 and 4 is a cylindrical member that is concentric with the device body 41 in the field of view in the direction of the central axis C2 of the device body 41.

[0049] The exterior member 42 includes a top plate 421, a bottom plate 422, and side walls 423. The top plate 421, bottom plate 422, and side walls 423 may be formed separately or integrally.

[0050] The top plate 421 is a plate-like member provided at a distance from the main body 41 of the device 41, on one end side of the main body 41 (the side facing the opposing surface 41x). The gap between the main body 41 of the device 41 and the inner surface 421x of the top plate 421 constitutes part of the sub-channel FP2. That is, the sub-channel FP2 extends around the entire radial circumference of the opposing surface 41x in a field of view along the central axis C2. The inner surface 421x of the top plate 421 and the opposing surface 41x are parallel.

[0051] The top plate 421 has an inlet 40a into which liquid L flows. The inlet 40a is a circular through-hole in plan view, and its central axis coincides with the opening A of the through-hole 41a of the device body 41. The flow path member 21 is connected to the separation device 40 at the inlet 40a. The central axis C1 of the inlet 40a and the central axis of the flow path 21a coincide.

[0052] The inner diameter D1 of the flow channel member 21 (inner diameter of the flow channel), i.e., the opening diameter D1 of the inlet 40a, is larger than the opening diameter D2 of the opening A of the main flow channel FP1 (through hole 41a). Therefore, in the field of view in the direction of the central axis C1, the flow channel member 21 overlaps with the through hole 41a. Ideally, the central axis C1 of the inlet 40a and the central axis C2 of the device body 41 (through hole 41a) should coincide.

[0053] Furthermore, the opening diameter D1 of the inlet 40a is smaller than the maximum outer diameter D3 of the device body 41 on the opposing surface 41x. Since the device body 41 in this embodiment is a cylindrical tubular member, the maximum outer diameter D3 is equal to the diameter of the device body 41.

[0054] The shape of the device body 41 is not limited to the cylindrical shape described above. For example, the device body 41 may be elliptical or polygonal. If the device body 41 is polygonal, it is preferable that the opposing surfaces have polygons with four or more sides. When the device body 41 is a cylindrical member of such a shape, it is preferable to use the diameter of the smallest circumscribed circle of the opposing surfaces as the maximum outer diameter D3.

[0055] Because the size of the inlet 40a and the size of the device body 41 are in the relationship described above, the device body 41 is positioned so as not to protrude from the inlet 40a towards the flow path 21a. Furthermore, the liquid L flowing through the flow path 21a is separated into a first liquid L1 that flows into the main flow path FP1 and a second liquid L2 that strikes the opposing surface 41x and flows into the sub-flow path FP2. The flow rates of the first liquid L1 and the second liquid L2 may be controlled independently, and the flow rate ratio of the first liquid L1 and the second liquid L2 may be controlled to be constant. In this case, the flow rate of the second liquid L2 may be made larger than the flow rate of the first liquid L1. The flow rates of the first liquid L1 and the second liquid L2 can be adjusted, for example, by providing pumps that flow the first liquid L1 and the second liquid L2 respectively on the downstream side of the separation device 40 and controlling the pumps.

[0056] The bottom plate 422 is a plate-shaped member that supports the main body 41 of the device and is provided on the other end side of the main body 41. The bottom plate 422 has a first outlet 40b that communicates with the main body 41. The first liquid L1 flowing through the main flow path FP1 is discharged to the outside of the separation device 40 from the first outlet 40b. The first outlet 40b corresponds to the "outlet" in this invention.

[0057] The side wall 423 is a cylindrical member that surrounds the device body 41 in the circumferential direction of the central axis C2. The device body 41 and the side wall 423 are spaced apart, and the gap between the device body 41 and the inner surface 423x of the side wall 423 constitutes part of the subflow channel FP2.

[0058] The side wall 423 has a second outlet 40c at the end on the bottom plate 422 side. The second liquid L2 flowing through the subflow channel FP2 is discharged to the outside of the separation device 40 from the second outlet 40c. A side pipe 45 is connected to the second outlet 40c.

[0059] The liquid L flowing into the separation device 40A flows towards either the main channel FP1 or the sub-channel FP2. A portion of the liquid L flows in the same direction as the flow direction in channel 21a and flows into the main channel FP1. The remaining portion of the liquid L changes its flow direction from channel 21a towards the gap between the opposing surface 41x and the inner surface 421x and flows into the sub-channel FP2. In the sub-channel FP2, the remaining portion of the liquid L flows isotropically in the radial direction of the central axis C1.

[0060] In this case, the pipeline resistance of the subchannel FP2 in the separation device 40A is set to be high. The pipeline resistance of such a sub-channel FP2 can be adjusted by controlling the width H between the opposing surface 41x and the inner surface 421x of the top plate 421, and the radial width R of the opposing surface 41x of the device body 41. Focusing on the widths H and R, the narrower the width H, the greater the pipeline resistance of the sub-channel FP2 tends to be. Also, the larger the width R, the greater the pipeline resistance of the sub-channel FP2 tends to be.

[0061] For example, the width H can be set to 2 times or less the opening diameter D2 of the opening A of the main flow path FP1 (through hole 41a). Preferably, the width H is 1 time or less of the opening diameter D2, more preferably 1 / 2 time or less, even more preferably 1 / 3 time or less, and especially preferably 1 / 4 time or less.

[0062] Furthermore, while the main channel FP1 extends in the same direction as the central axis C1, the secondary channel FP2 is positioned perpendicular to the main channel FP1, i.e., perpendicular to the central axis C1. This difference in the direction of extension of each channel also results in a difference in pipe resistance.

[0063] (Function of the separation device) Figure 5 is an explanatory diagram illustrating the function of the separation device 40A, and is a schematic diagram showing the state of the flow path 21a.

[0064] First, in the convergence section 20A located upstream of the separation device 40A, the fine particles P (not shown) contained in the fluid in the flow path are converged to the center of the flow path. At this time, the position where the fine particles P flow in the flow path 21a can be approximated as a roughly circular region near the center of the cross-section of the flow path 21a. In Figure 5(a), the region where the fine particles P flow is indicated by the symbol AR1, and the center of region AR1 is indicated by the symbol P1.

[0065] On the other hand, regarding the liquid L supplied from flow path 21a to the separation device 40A, it can be confirmed which part of the liquid in the flow path flows into the main flow path FP1 using known fluid simulation software (COMSOL multiphysics ver6.2, manufactured by COMSOL). For example, when liquid L is supplied to the separation device 40A under the following simulation conditions, it can be confirmed that a roughly circular region near the center of the cross-section of flow path 21a flows into the main flow path FP1. (Simulation conditions) Width H: 0.125mm, Width R: 2mm Inner diameter D1 of channel 21a: 0.8 mm, Inner diameter D2 of main channel: 0.5 mm Flow rate of liquid introduced from channel 21a to separation device 40A: 10 mL / min Flow rate ratio of the second liquid L2 to the first liquid L1: L2:L1 = 9:1

[0066] In Figure 5(b), in addition to region AR1, the region of liquid flowing into the main channel FP1 in the cross-section of channel 21a is indicated by the symbol AR2. In Figure 5(b), region AR2 is approximated as a circular region, and its center is indicated by the symbol P2. If region AR2 is not circular, the symbol P2 indicates the centroid of region AR2.

[0067] In this case, the central axis C1 of the inlet 40a (the central axis of the flow path 21a) and the central axis C2 of the main flow path FP1 coincide, and as shown in Figure 5(b), when region AR1 is contained within region AR2, it can be understood that the region in which the fine particles P flow preferably flows into the main flow path FP1 as the first liquid L1.

[0068] However, if the central axes C1 and C2 do not coincide, the first liquid L flowing through region AR1 is expected not to flow into the main channel FP1, but instead to collide with the opposing surface 41x and flow into the sub-channel FP2. In conventional separation units using double-walled pipes, if the central axes of the inner and outer pipes are misaligned, the first liquid may not flow into the inner pipe corresponding to the main channel FP1, but may leak out into the outer pipe corresponding to the sub-channel FP2. In separation units with such a configuration, the central axis of the inner pipe (main channel) and the central axis of the outer pipe (sub-channel) coincide with the flow direction of the liquid flowing through the channels, so there is little difference in the ease with which the liquid flows into the inner pipe and the ease with which it flows into the outer pipe. For this reason, in conventional separation units using double-walled pipes, the assembly accuracy easily affected the efficiency of separating the first liquid, i.e., the efficiency of separating fine particles.

[0069] In contrast, in the separation device 40A, even if the central axis of the flow path 21a (i.e., the central axis C1 of the inlet 40a) and the central axis C2 of the main flow path FP1 do not coincide, and there is a radial displacement of the central axis, simulations have confirmed that the first liquid L1 is less likely to flow into the sub-flow path FP2. Therefore, the separation device 40A can reduce the influence of assembly accuracy on the preparative efficiency.

[0070] As described above, if the central axes C1 and C2 do not coincide, it is conceivable that turbulence in the liquid flow will occur near the opening A due to the misalignment. Such turbulence in the flow is thought to create new pipeline resistance (referred to as pipeline resistance Rα) near the opening A, affecting the flow of liquid L into the main channel FP1 and the secondary channel FP2.

[0071] On the other hand, in the separation device 40A, the pipe resistance of the subflow channel FP2 (referred to as pipe resistance R2) is set to be large by controlling the widths H and R as described above. Therefore, the newly generated pipe resistance Rα is considered to be sufficiently small compared to pipe resistance R2, and the difference between pipe resistance R2 and pipe resistance R2 + pipe resistance Rα becomes small.

[0072] As a result, in the separation device 40A, even if the central axis C1 of the inlet 40a and the central axis C2 of the main flow path FP1 do not coincide due to manufacturing errors or distortion of the device, the effects of such misalignment are reduced, and the liquid L can be suitably separated.

[0073] Figure 5(c) is a schematic diagram showing the relationship between regions AR1 and AR2 within the flow path 21a when there is a misalignment between the central axes C1 and C2. When the above simulation software is used and liquid L is flowed under the above simulation conditions, even if there is a 100 μm radial misalignment between the central axes C1 and C2, the distance (misalignment) D between the center P1 of region AR1 and the center P2 of region AR2 will be 10.5 μm. In other words, it can be seen that the separation device 40A can reduce the effect of the misalignment between the central axes C1 and C2.

[0074] With a separation apparatus configured as described above, the problem of the first liquid L1 flowing into the subchannel FP2 is suppressed, and fine particles concentrated in the center of the channel can be easily separated.

[0075] Furthermore, a fluid device with the above configuration makes it possible to easily concentrate fine particles in a liquid.

[0076] [Second Embodiment] The separation apparatus and fluid device according to the second embodiment will be described below with reference to Figures 6 to 8. In this embodiment, components common to the first embodiment are denoted by the same reference numerals, and detailed descriptions are omitted.

[0077] Figure 6 is a schematic perspective view showing the separation device 40B and fluid device of this embodiment. Figure 7 is a cross-sectional view taken along the line segment VII-VII in Figure 6. Figure 8 is a cross-sectional view taken along the line segment VIII-VIII in Figure 6. As shown in Figures 6-8, the fluid device 100B of this embodiment includes a supply unit 10, a convergence unit 20A, a control unit 30, and the separation device 40B of this embodiment.

[0078] The separation device 40B comprises a plurality of device bodies 41 and an exterior member 46.

[0079] (Exterior components) The exterior member 46 is a member that commonly houses multiple device bodies 41. The exterior member 46 includes a top plate 461, a bottom plate 462, and side walls 463. The top plate 461, bottom plate 462, and side walls 463 may be formed separately or integrally.

[0080] The exterior member 46 has an internal space S that houses the device body 41. The internal space S is enclosed by a top plate 461, a bottom plate 462, and side walls 463. Multiple device bodies 41 are arranged in one direction within the internal space S.

[0081] The top plate 461 is a plate-shaped member provided at a distance from the main body 41 and on one end side of the main body 41. The gap between the main body 41 and the inner surface 461x of the top plate 461 constitutes part of the sub-channel FP2. That is, the sub-channel FP2 extends around the entire radial circumference of the opposing surface 41x in a field of view along the central axis of each main body 41.

[0082] The top plate 461 has multiple inlets 40a into which liquid L flows. The flow path member 21 is connected to the separation device 40 at the inlets 40a. Each inlet 40a overlaps with a through-hole 41a of each device body 41.

[0083] The bottom plate 462 is a plate-shaped member that supports the device body 41 and is provided on the other end side of the device body 41. The bottom plate 462 has a plurality of first outlets 40b that communicate with each device body 41. The first liquid L1 flowing through the main flow path FP1 is discharged from the first outlets 40b. The first outlets 40b may gradually widen in diameter toward the downstream side.

[0084] The side wall 463 is a closed annular member that surrounds the multiple device bodies 41. Each device body 41 and the side wall 463 are spaced apart, and the gap between the device body 41 and the inner surface 463x of the side wall 463 constitutes part of the sub-flow channel FP2.

[0085] The side wall 463 has a second outlet 40c that extends in the longitudinal direction (the same direction as the arrangement direction of the device body 41). The second liquid L2 flowing through the subflow channel FP2 is discharged to the outside of the separation device 40 from the second outlet 40c.

[0086] The separation device 40B has a confluence section 47. The confluence section 47 is a space enclosed by a side wall 463, a bottom plate 462, and a bottom plate 464, and communicates with a plurality of first outlets 40b on the downstream side, and is a space that allows the first liquid L1 discharged from the first outlets 40b to flow in common. An outlet 47a is provided on the downstream side of the confluence section 47. The first liquid L1 discharged into the confluence section 47 is discharged collectively to the outside of the separation device 40B through the outlet 47a.

[0087] In the diagram, the separation device 40B is shown with the bottom plate 462 supporting the main body 41 also serving as part of the confluence section 47, and the entire device is formed as a single unit, but this is not limited to this configuration. The separation device 40B may also have a separate component that has the same function as the confluence section 47. For example, such a configuration may include a piping system having pipes connected to each first outlet 40b and branch joints that bring the pipes together.

[0088] With a separation device configured as described above, it becomes possible to easily separate the fine particles concentrated in the center of the flow path.

[0089] Furthermore, a fluid device with the above configuration makes it possible to easily concentrate fine particles in a liquid.

[0090] In the above-described embodiment, the main body of the separation device is cylindrical, and the sub-flow channel FP2 is formed isotropically in the radial direction of the central axis C1, but this is not limited to this. For example, within the limits that do not impede the effects of the invention, the main body 41 of the device may be in partial contact with the inner surface of the exterior member (inner surface of the top plate, inner surface of the side wall), and the sub-flow channel FP2 may not be formed at the contact points between the main body 41 of the device and the exterior member.

[0091] Furthermore, while the above-described embodiment shows a configuration utilizing acoustic focusing as the focusing section of the fluid device, any known technique for focusing fine particles contained in the fluid in the pipe to the center of the pipe can be appropriately adopted. Examples of such techniques include acoustic focusing, inertial focusing, probabilistic separation, dielectrophoresis, and magnetophoresis, and can be appropriately adopted depending on the properties of the fine particles contained in the liquid and the properties of the liquid.

[0092] Furthermore, the method of acoustic convergence is not limited to the method of the embodiment described above.

[0093] Through the inventor's investigation, it was found that the "ultrasonic vibration that generates a standing wave W within the flow path" applied to the flow path member in the convergence section differs depending on various conditions, such as the shape and size of the flow path, the temperature of the liquid L flowing within the flow path, and the relative position of the flow path with respect to the transducer 222. For example, as shown in Figure 1, when ultrasonic vibration is applied to multiple flow paths from a single transducer, even if flow paths of the same shape and size are prepared, the actual dimensions of the flow paths will differ due to manufacturing tolerances. Due to these differences in actual dimensions, it is thought that the appropriate frequency for ultrasonic vibration to concentrate sound will differ for each flow path. In addition, it was thought that various influences, such as the arrangement (relative position) of each flow path with respect to the transducer and changes in the temperature of the liquid flowing inside, would make it difficult to set an appropriate frequency.

[0094] Therefore, in the fluid device of this embodiment, the control unit 30 may determine the ultrasonic vibration that generates a standing wave for each flow path, and may also generate a composite vibration of the ultrasonic vibrations that generate standing waves for each flow path in the transducer. For example, in the relationship between the first flow path 211a and the second flow path 212a shown in Figure 1, the control unit 30 may create a drive signal that generates a composite vibration in the transducer of a first ultrasonic vibration having a first frequency that generates a standing wave in the first flow path 211a and a second ultrasonic vibration having a second frequency that generates a standing wave in the second flow path 212a, and supply this signal to the transducer 222.

[0095] Figure 9 is a block diagram illustrating the configuration of the control unit 30. The control unit 30 includes an input means 31, a temperature sensor (detection means) 32, and a control device 33.

[0096] The input means 31 can include an input device for inputting instructions to the control device 33, or the power switch of the control device 33. Examples of instructions input from the input means 31 include, for example, • Actual dimensions of each channel • The range of manufacturing tolerances relative to the design values ​​of the flow path (the upper and lower limits of the dimensions of the flow path that are expected) • Correspondence between the dimensions of the first channel 211a and the frequency of the first ultrasonic vibration (first frequency) that generates a standing wave in the first channel 211a. • The temperature range over which liquid L can change temperature (the upper and lower limits of the temperature of liquid L that are assumed) • Correlation between the temperature of liquid L and the frequency of the first ultrasonic vibration (first frequency) that generates a standing wave in the first channel 211a. • The same correspondence as above for the second and third channels. These are some examples.

[0097] Furthermore, if the frequency of the first ultrasonic vibration has been confirmed through preliminary experiments, the frequency of the first ultrasonic vibration may be input from the input means 31.

[0098] The temperature sensor 32 detects the temperature of the liquid L flowing through the flow path. In Figure 1, one temperature sensor 32 is installed in the main pipe 120 of the piping 12, and it is intended to detect the temperature of the liquid L inside the main pipe 120. In this case, it is assumed that the liquid L flowing through the first flow path 211a, the second flow path 212a, and the third flow path 213a are all at the same temperature.

[0099] Furthermore, the temperature sensor 32 may be provided in each of the branch pipes 121, 122, and 123 shown in Figure 1. In addition, the temperature sensor 32 may be provided in the flow path member 21. In this case, the temperature sensor 32 may be provided on the upstream side of the vibrating section 22, or on the downstream side of the vibrating section 22.

[0100] The control device 33 generates a drive signal for the vibrator 222 based on the detection results from the temperature sensor 32 and the instructions input from the input means 31, and supplies it to the vibrator 222. The control device 33 includes a measurement unit 331, a storage unit 332, a determination unit 333, and a signal generation unit 334. For the sake of explanation, the measurement unit 331, storage unit 332, determination unit 333, and signal generation unit 334 are shown separately in the diagram, but these are processing blocks and do not need to be physically separated within the control device 33.

[0101] The measuring unit 331 receives the detection result detected by the temperature sensor 32 as an electrical signal and calculates the temperature of the liquid L from the received electrical signal. The measuring unit 331 may continuously receive the detection results continuously detected by the temperature sensor 32 and continuously determine the temperature of the liquid L, or it may receive the detection results intermittently and intermittently determine the temperature of the liquid L.

[0102] The memory unit 332 stores the above correspondences input from the input means 31. The correspondences may be stored in advance. In Figure 9, the memory unit 332 is shown as a component of the control device 33, but it is not limited to this. An external storage medium may be used as the memory unit 332. The above correspondences can be stored in the form of mathematical formulas or lookup tables.

[0103] The determination unit 333 receives information regarding at least one of "dimensions of the flow path" and "temperature of the liquid," such as the temperature of the liquid L determined by the measurement unit 331, the actual dimensions of the flow path input from the input means 31, the range of manufacturing errors between the design value of the flow path and the storage unit 332, and the temperature range in which the liquid L can change temperature. Based on this information and the corresponding relationships stored in the storage unit 332, the determination unit 333 determines ultrasonic vibrations that generate standing waves in the flow path. Specifically, the determination unit 333 determines a first ultrasonic vibration having a first frequency that generates standing waves in the first flow path 211a, a second ultrasonic vibration having a second frequency that generates standing waves in the second flow path 212a, and a third ultrasonic vibration having a third frequency that generates standing waves in the third flow path 213a.

[0104] Furthermore, if the determination unit 333 obtains information on the temperature range in which the liquid L can change temperature, the determination unit 333 may determine the first ultrasonic vibration as a composite vibration of a high-temperature ultrasonic vibration determined based on the correspondence between the upper limit temperature of the temperature range and the first frequency, and a low-temperature ultrasonic vibration determined based on the correspondence between the lower limit temperature and the first frequency. The composite vibration can be created by the method described later.

[0105] The signal generation unit 334 generates a drive signal that causes the transducer 222 to produce a combined vibration of the first to third ultrasonic vibrations determined by the determination unit 333.

[0106] The signal generation unit 334 may determine a composite waveform of the vibration waveform of the first ultrasonic vibration, the vibration waveform of the second ultrasonic vibration, and the vibration waveform of the third ultrasonic vibration, and create a drive signal that generates ultrasonic vibrations having the composite waveform in the transducer 222.

[0107] Figure 10 is an explanatory diagram illustrating the composite waveform. Figure 10(a) is a graph showing the waveforms of three ultrasonic vibrations UV1 to UV3 at different frequencies generated by the transducer 222, and Figure 10(b) is a graph showing the results of the Fourier transform of the ultrasonic vibrations UV1 to UV3 waveforms.

[0108] As shown in Figures 10(a) and 10(b), for example, the waveforms of three ultrasonic vibrations with different frequencies (first ultrasonic vibration UV1, second ultrasonic vibration UV2, and third ultrasonic vibration UV3) are each Fourier transformed, and after creating a peak by superimposing the resulting transformed peaks, an inverse Fourier transform is performed to obtain a composite waveform CW.

[0109] Even if a single-frequency ultrasonic vibration UV1 is generated in the transducer 222, as shown in the waveform after the Fourier transform, the ultrasonic vibration UV1 has a frequency spread (peak width PW) of a certain width. Furthermore, even if the frequencies of the ultrasonic vibrations that generate standing waves differ due to manufacturing errors during the production of the flow channel or temperature changes in the liquid L, these differences are minute. Therefore, it is unlikely that there will be large differences in the frequencies of each ultrasonic vibration before synthesis, and it is thought that the peaks after the Fourier transform will often overlap with each other.

[0110] Therefore, the synthesized waveform CW can be considered to include not only the frequencies of the peaks of the three original ultrasonic vibrations, but also the vibration components of the frequencies between the peaks of the three ultrasonic vibrations. By generating ultrasonic vibrations with the synthesized waveform CW obtained in this way in the transducer 222, standing waves can be generated in the flow path even if there are manufacturing errors in the flow path or temperature changes in the liquid L.

[0111] To generate a standing wave appropriately within the flow path, the amplitudes of the three ultrasonic vibrations that form the basis of the synthesis may be adjusted as needed when obtaining a synthesized CW waveform.

[0112] In addition to the process of determining the composite waveform CW by combining each ultrasonic vibration as described above, the signal generation unit 334 may also create a drive signal that changes the frequency of the vibration generated in the transducer 222 between the first frequency, the second frequency, and the third frequency within a unit time. Here, "unit time" is a time of 100 milliseconds or less, and can be set within the range of 0.001 milliseconds to 100 milliseconds.

[0113] As described above, the unit time for changing the frequency can be set considering the time the microparticles are present in the flow path. For example, when the liquid in the flow path forms a laminar flow, it is known that the flow velocity at the center of the laminar flow is approximately twice the average flow velocity. Taking such differences in liquid flow velocity into account, if it is calculated that the liquid near the center of the flow path passes through the flow path member in 240 milliseconds, then the unit time for applying two types of ultrasonic vibrations should be set to 100 milliseconds or less. This ensures that even microparticles flowing with the fastest-moving liquid in the flow path can be reliably acoustically focused by the two types of ultrasonic vibrations.

[0114] Furthermore, by setting the required unit time even shorter as described above, it is possible to average out the effects of the multiple types of ultrasonic vibrations applied, which is preferable. In the above example, by setting the vibration switching unit time to 10 milliseconds, the two types of ultrasonic vibrations can be applied to the fine particles passing through the flow path 10 or more times each. Following a similar line of reasoning, it is preferable for the unit time to be, for example, 1 millisecond.

[0115] The lower limit of the unit time should be set based on the period of the applied ultrasonic vibration. For example, since one period of 1 MHz (1000 kHz) ultrasonic vibration is 0.001 milliseconds, it is advisable to set the unit time to 0.001 milliseconds or more.

[0116] As described above, when creating a drive signal that changes the vibration frequency over time, the control device 33 always handles only one type of drive signal. Therefore, compared to the case where the control device 33 handles multiple drive signals simultaneously and creates a composite waveform CW drive signal, power consumption is reduced and heat generation during operation of the device can be suppressed.

[0117] Furthermore, when multiple flow channel members 21 are vibrated by a single transducer 222, even if the same material is used for the multiple flow channel members, manufacturing tolerances may cause differences in the ultrasonic vibrations that generate standing waves within the piping. Moreover, if the thickness of the transducer 222 differs due to manufacturing tolerances, it may not be possible to supply the same vibration to the flow channel members commonly attached to the transducer 222. In such cases, it becomes difficult to determine the composite waveform CW and to supply ultrasonic vibrations corresponding to the composite waveform CW to the flow channel members.

[0118] On the other hand, when the vibration frequency is varied over time as described above, it becomes easier to find conditions that allow for appropriate acoustic convergence in all flow path members, and control becomes easier.

[0119] As an example, when applying vibrations of two different vibration frequencies to multiple flow channel members 21, the vibration frequencies can be set as follows.

[0120] First, the theoretical resonant frequency of the flow channel member 21 is calculated using known analytical methods such as finite element analysis. Next, preliminary experiments are conducted in which a liquid containing fine particles is flowed through multiple flow channel members 21 while vibrations at frequencies within ±10% of the obtained resonant frequency are applied, thereby determining multiple (e.g., two) vibration frequencies at which the fine particles converge appropriately. By applying vibrations at these determined frequencies to multiple flow channel members 21 from a single oscillator 222 while varying the time, for example, by 1 millisecond, it becomes possible to achieve suitable acoustic convergence in multiple flow channel members 21.

[0121] The control unit 30 supplies the drive signal created as described above to the transducer 222, driving the transducer 222. The transducer 222 generates ultrasonic vibrations corresponding to the composite waveform CW, causing the flow channel member to vibrate. In each flow channel, standing waves W1 and W2 are generated by ultrasonic components included in the composite waveform CW, with ultrasonic components having frequencies corresponding to each flow channel. As a result, acoustic focusing can be achieved in the fluid device.

[0122] In the convergence section of the fluid device, acoustic convergence may be performed as described above.

[0123] Furthermore, although the apparatus body 41 is configured as a straight tube in the above-described embodiment, it is not limited to this. For example, the through hole 41a may be bent or curved inside the apparatus body 41, and the first liquid may be discharged from a first outlet provided on the side wall of the exterior member.

[0124] Furthermore, in the above-described embodiment, the second discharge port is provided on the side wall of the exterior member, but it is not limited to this configuration, and may also be provided on the bottom plate.

[0125] Preferred embodiments of the present invention have been described above with reference to the attached drawings, but the present invention is not limited to these examples. The shapes and combinations of the constituent members shown in the above examples are merely examples, and can be modified in various ways based on design, specifications, etc., without departing from the spirit of the present invention. [Explanation of Symbols]

[0126] 12…piping, 20A…bundle section, 21…flow path components, 21a…flow path, 22…vibration section, 40A, 40B…separation device, 40a…inlet, 40b…first outlet, 40c…second outlet, 41…device body, 41a…through hole, 41x…opposite surface, 42, 46…external components, 47…merging section, 47a…outlet, 100A, 100B… Fluid valve, 221...vibration plate, 221a...main surface, 222...vibrator, 421, 461...top plate, 421x, 423x, 461x, 463x...inner surface, 422 ,462,464…bottom plate, 423,463…side wall, C1, C2…central axis, FP1…main flow path, FP2…auxiliary flow path, L…liquid, L1…first liquid, L2…second liquid

Claims

1. A separation device connected to a flow channel for a liquid, which separates the liquid into a first liquid flowing through the center of the flow channel and a second liquid flowing along the inner wall of the flow channel, A device body having a through hole, The device comprises an exterior member that houses the main body of the device, The exterior member is positioned at a distance from the main body of the device and has a top plate on which an inlet is provided to which the flow path is connected. The through-hole opens to the surface of the apparatus body facing the top plate and serves as the main flow path for the first liquid. The space between the top plate and the opposing surface is a sub-channel for the flow of the second liquid. The opening of the through hole overlaps with the inlet in the central axis direction of the inlet, A separation device in which the opening diameter of the inlet is larger than the opening diameter of the through hole on the opposing surface and smaller than the maximum outer diameter of the device body on the opposing surface.

2. The separation device according to claim 1, wherein the through hole extends in the direction of the central axis.

3. The aforementioned opposing surfaces are annular in shape. The aforementioned opening is circular, The separation device according to claim 2, wherein the center position of the opposing surface and the center position of the opening coincide.

4. The separation device according to any one of claims 1 to 3, wherein the opposing surface and the inner surface of the top plate are parallel.

5. The exterior member has a bottom plate that faces the top plate and supports the main body of the device, The separation device according to any one of claims 1 to 3, wherein the bottom plate has an outlet that communicates with the through hole and discharges the first liquid.

6. The separation device comprises a plurality of the device bodies, The device has an exterior member that commonly houses the multiple device bodies, The separation device according to any one of claims 1 to 3, wherein the top plate has a plurality of inlets that each overlap with a plurality of through holes of the plurality of the device bodies.

7. The separation device according to claim 6, having a confluence section that communicates with multiple through-holes of the device body on the downstream side.

8. It has a channel through which a liquid containing particles flows, and a convergence section that converges the particles to the center of the channel while the liquid flows, A fluid device comprising: a separation device according to any one of claims 1 to 3, which is connected downstream of the convergence section and separates the liquid into a first liquid and a second liquid.

9. The convergence portion comprises a flow channel member having a flow channel through which the liquid flows, It has a vibrating part that vibrates the aforementioned flow channel member, The vibrating section comprises a vibrating plate on which the flow channel member is attached to the main surface, The fluid device according to claim 8, further comprising a vibrator that vibrates the diaphragm in the thickness direction of the diaphragm.

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