Vortex-type fluid mixer

Abstract

A vortex flow type fluid mixer (111) comprises: a vortex chamber (25) defined by a cylindrical peripheral side wall (13) extending along a vortex chamber central axis O, and a first end wall (15) and a second end wall (17) provided at both ends of the peripheral side wall (13) and facing each other; an inlet flow path (19) connected to an inlet opening (27) provided in the peripheral side wall (13); and an outlet flow path (21) connected to an outlet opening (29) provided in the second end wall (17) or in the region of the peripheral side wall (13) adjacent to the second end wall (17). A protrusion (31) protruding toward the vortex chamber central axis (O) is provided on the peripheral side wall (13) between the inlet opening (27) and the second end wall (17) in the vortex chamber central axis (O) direction, and a throttle part is formed between the first end wall (15) and the second end wall (17) by the protrusion (31).

Description

Vortex-type fluid mixer

[0001] The present invention relates to a vortex-type fluid mixer that is used in fluid transport pipes in various industries such as chemical plants, semiconductor manufacturing fields, food fields, medical fields, and bio fields, and mixes two or more kinds of fluids using vortices.

[0002] In various industrial fields such as chemical plants, semiconductor manufacturing fields, food fields, medical fields, and bio fields, fluid mixers may be used to mix different types of fluids. As one such fluid mixer, there is a vortex-type fluid mixer that mixes different types of fluids using vortices, as described in Patent Document 1 and Patent Document 2. For example, in Patent Document 1, a plurality of fluid inlets are provided at the lowermost end of a mixing tank so as to generate a swirling flow in the same direction in the mixing tank by introducing fluids, and the mixed fluid mixed by a spiral flow in the mixing tank is discharged from a fluid outlet provided at the uppermost end of the mixing tank. A continuous mixing device is disclosed. Further, in Patent Document 2, there are provided a vortex chamber (mixing tank) defined by a cylindrical peripheral side wall and first and second end walls provided at both ends thereof, an inlet flow path opening in the peripheral side wall, an outlet flow path opening in the first end wall, and a protruding portion protruding into the vortex chamber from at least one of the first end wall and the second end wall. The inlet flow path is provided such that the inlet flow path axis passes through a position separated from the center axis of the vortex chamber. When the fluid that has merged upstream of the inlet flow path flows into the vortex chamber through the inlet flow path, the vortex chamber is configured to form a vortex, and the fluid mixed by forming a vortex in the vortex chamber flows out from the outlet flow path. A vortex-type fluid mixer is disclosed.

[0003] Japanese Patent Application Laid-Open No. 2006-167600, Patent No. 7457193

[0004] In fluid mixers such as those described in Patent Document 1 and Patent Document 2, since a swirling flow occurs along the peripheral wall of the mixing tank or the vortex chamber, the fluid is not sufficiently mixed inside the mixing tank or the vortex chamber, and mixing unevenness may occur between the inside and the outside of the mixing tank or the vortex chamber. Such mixing unevenness causes variations in the concentration distribution. For example, in a semiconductor wafer manufacturing line, when a chemical solution with a concentration variation is applied to a semiconductor wafer, it causes defective products.

[0005] Therefore, the object of the present invention is to solve the problems of the prior art and to suppress the occurrence of uneven mixing between the outside and inside of the vortex chamber in a vortex-type fluid mixer.

[0006] In view of the above objectives, the present invention provides a vortex-type fluid mixer for mixing two or more fluids using a vortex flow, comprising: a vortex chamber defined by a cylindrical circumferential wall extending along the central axis of the vortex chamber and a first end wall and a second end wall provided at both ends of the circumferential wall and facing each other; an inlet passage connected to an inlet opening provided in the circumferential wall and extending along an inlet passage central axis passing away from the central axis of the vortex chamber; and an outlet passage connected to an outlet opening provided in the second end wall or in an adjacent area of ​​the circumferential wall, wherein a projection is provided in the circumferential wall between the inlet opening and the second end wall in the direction of the central axis of the vortex chamber, and the projection forms a throttling portion between the first end wall and the second end wall.

[0007] In the above-described vortex-type fluid mixer, the vortex chamber is defined by a cylindrical circumferential wall and opposing first and second end walls at both ends. The inlet channel is connected to an inlet opening in the circumferential wall and extends along the inlet channel's central axis, which is located away from the vortex chamber's central axis. The outlet channel opens to the second end wall or to an adjacent area of ​​the circumferential wall. Therefore, a mixed fluid containing two or more types of fluids flowing in from the inlet channel becomes a swirling flow within the vortex chamber and flows in a vortex before flowing out through the outlet channel. As a result, the mixing fluid flowing into the vortex chamber from the inlet channel can reduce variations in the concentration of different types of fluids (unevenness in concentration distribution) due to the stirring action of the vortex flow within the vortex chamber. Furthermore, a projection is provided between the inlet opening and the second end wall in the direction of the vortex chamber's central axis on the circumferential wall of the vortex chamber, forming a throttling section. Therefore, the swirling flow passes through the throttling section within the vortex chamber before being discharged from the outlet channel. In the constricted section, the radial dimension of the vortex chamber is reduced by the protrusions. Therefore, when the swirling flow reaches the constricted section, a flow is generated radially toward the central axis of the vortex chamber. As a result, variations in radial concentration within the vortex chamber are reduced, and uneven mixing is suppressed.

[0008] In one embodiment, the projection can be an annular projection. In this case, the inner circumferential surface of the throttling portion can have a circular, elliptical, or polygonal shape when viewed in the direction of the central axis of the vortex chamber, for example.

[0009] In other embodiments, the projection may be provided only on a portion of the circumferential side wall. In this case, the ridge of the projection may have, for example, an arc shape or a shape formed by connecting multiple straight lines when viewed in the direction of the central axis of the vortex chamber.

[0010] In the above-described vortex-type fluid mixer, the protrusions may be provided at multiple positions in the direction of the central axis of the vortex chamber.

[0011] In the above-described vortex-type fluid mixer, the second end wall may have a weight shape or a hemispherical shape.

[0012] In the above-described vortex-type fluid mixer, it is preferable that the cross-sectional area of ​​the smallest opening of the throttling portion is larger than the cross-sectional area of ​​the inlet flow path. This prevents the protrusion from restricting the flow rate.

[0013] In the above-described vortex-type fluid mixer, it is preferable that the diameter of the vortex chamber is larger than the diameter of the inlet flow path.

[0014] In the above-described vortex-type fluid mixer, the first end wall may be formed by a diaphragm that is deformable in the direction of the central axis of the vortex chamber.

[0015] According to the present invention, a vortex flow is generated within the vortex chamber, and the stirring action of the vortex flow within the vortex chamber reduces variations in the concentration of different types of fluids (unevenness in concentration distribution). Furthermore, since a constriction is formed by a projection provided between the inlet opening and the second end wall in the direction of the vortex chamber's central axis, a flow is generated radially toward the vortex chamber's central axis. As a result, variations in radial concentration within the vortex chamber can be further reduced, and the effect of suppressing uneven mixing can be achieved.

[0016] This is a partially cutaway perspective view showing the overall configuration of the vortex fluid mixer of the first embodiment according to the present invention, with a portion cut away to allow the interior to be seen. This is an explanatory diagram showing the streamlines representing the fluid flow when the second end wall of the vortex fluid mixer is circular and flat and the outlet channel is connected to the circumferential side wall and extends in a direction perpendicular to the central axis of the vortex chamber. This is an explanatory diagram showing the streamlines representing the fluid flow when the second end wall of the vortex fluid mixer is hemispherical and the outlet channel is connected to the center of the hemispherical second end wall and extends in a direction perpendicular to the central axis of the vortex chamber. This is a plan view of the vortex fluid mixer of the second embodiment, which has a deformed projection, as seen in the direction of the central axis of the vortex chamber. This is a side view of the vortex fluid mixer of the second embodiment, which has a deformed projection, as seen from the direction of arrow A in Figure 4A. This is a side view of the vortex fluid mixer of the second embodiment, which has a deformed projection, as seen from the direction of arrow B in Figure 4A. This is a plan view of a third embodiment of a vortex-type fluid mixer equipped with a deformed projection, viewed in the direction of the vortex chamber's central axis. This is a side view of a third embodiment of a vortex-type fluid mixer equipped with a deformed projection, viewed from the direction of arrow C in Figure 5A. This is a side view of a third embodiment of a vortex-type fluid mixer equipped with a deformed projection, viewed from the direction of arrow D in Figure 5A. This is a side view showing a vortex-type fluid mixer according to the fourth embodiment of the present invention. This is a side view showing a vortex-type fluid mixer according to the fifth embodiment of the present invention. This is a side view showing a vortex-type fluid mixer according to the sixth embodiment of the present invention. This is an explanatory diagram for explaining the configuration and dimensions of a vortex-type fluid mixer model equipped with a projection used in a numerical simulation to verify the effect of the projection, showing the vortex-type fluid mixer model viewed from the first end wall side in the direction of the vortex chamber's central axis. This is an explanatory diagram for explaining the configuration and dimensions of a vortex-type fluid mixer model equipped with a projection used in a numerical simulation to verify the effect of the projection, showing the vortex-type fluid mixer model viewed from a direction perpendicular to the vortex chamber's central axis. This is an explanatory diagram illustrating the configuration and dimensions of a vortex-flow fluid mixer model without protrusions, used in numerical simulations to verify the effect of the protrusions. It shows the vortex-flow fluid mixer model as viewed from the first end wall side in the direction of the vortex chamber's central axis.This is an explanatory diagram illustrating the configuration and dimensions of a vortex-flow fluid mixer model without protrusions used in numerical simulations to verify the effect of protrusions, showing the vortex-flow fluid mixer model viewed from a direction perpendicular to the vortex chamber's central axis. This is a bar graph comparing the difference between the maximum and minimum values ​​of the passive scalar of the mixed fluid at the mixing uniformity measurement position, obtained by numerical simulations using a vortex-flow fluid mixer with protrusions and a vortex-flow fluid mixer without protrusions. This is an explanatory diagram illustrating the configuration and dimensions of a vortex-flow fluid mixer model used in numerical simulations to verify the effect of the shape of the protrusions, in which the minimum opening of the throttling portion formed by the protrusions has a triangular shape when viewed in the direction of the vortex chamber's central axis, showing the vortex-flow fluid mixer model viewed from the first end wall side in the direction of the vortex chamber's central axis. This is an explanatory diagram illustrating the configuration and dimensions of a vortex-flow fluid mixer model used in numerical simulations to verify the effect of the shape of the protrusions, in which the minimum opening of the throttling portion formed by the protrusions has a triangular shape when viewed in the direction of the vortex chamber's central axis, showing the vortex-flow fluid mixer model viewed from a direction perpendicular to the vortex chamber's central axis. This is an explanatory diagram for describing the configuration and dimensions of a vortex-type fluid mixer model used in numerical simulations to verify the effect of the shape of the protrusions, in which the smallest opening of the throttling portion formed by the protrusions has a triangular shape when viewed in the direction of the vortex chamber's central axis, and shows the vortex-type fluid mixer model viewed from a direction rotated 90° clockwise from the direction of Figure 15 around the vortex chamber's central axis. This is an explanatory diagram for describing the configuration and dimensions of a vortex-type fluid mixer model used in numerical simulations to verify the effect of the shape of the protrusions, in which the smallest opening of the throttling portion formed by the protrusions has an arc shape when viewed in the direction of the vortex chamber's central axis, and shows the vortex-type fluid mixer model viewed from the first end wall side in the direction of the vortex chamber's central axis. This is an explanatory diagram for describing the configuration and dimensions of a vortex-type fluid mixer model used in numerical simulations to verify the effect of the shape of the protrusions, in which the smallest opening of the throttling portion formed by the protrusions has an arc shape when viewed in the direction of the vortex chamber's central axis, and shows the vortex-type fluid mixer model viewed from a direction perpendicular to the direction of the vortex chamber's central axis.This is an explanatory diagram for describing the configuration and dimensions of a vortex-flow fluid mixer model used in numerical simulations to verify the effect of the shape of the protrusions, in which the minimum opening of the throttling portion formed by the protrusions has an arc shape when viewed in the direction of the vortex chamber's central axis. It shows the vortex-flow fluid mixer model as viewed from a direction rotated 90° clockwise from the direction shown in Figure 18 around the vortex chamber's central axis. This is a bar graph comparing the difference between the maximum and minimum values ​​of the passive scalar of the mixed fluid at the mixing unevenness measurement position, obtained by numerical simulations using vortex-flow fluid mixers with different shapes when viewed in the direction of the vortex chamber's central axis.

[0017] Hereinafter, embodiments of the vortex-type fluid mixer according to the present invention will be described with reference to the drawings. First, the overall configuration of the vortex-type fluid mixer 111 of the first embodiment will be described with reference to Figure 1.

[0018] The vortex-type fluid mixer 111 comprises a cylindrical circumferential wall 13 extending along a central axis, a first end wall 15 and a second end wall 17 provided opposite each other at both ends of the circumferential wall 13 in the direction of the central axis, an inlet passage 19, an outlet passage 21, and a confluence section 23 provided upstream of the inlet passage 19. The first end wall 15 and the second end wall 17 are provided to close both ends of the circumferential wall 13 in the direction of the central axis, and the space surrounded by the circumferential wall 13, the first end wall 15 and the second end wall 17 constitutes a vortex chamber 25. The central axis O of the vortex chamber, which extends to connect the center of the first end wall 15 and the center of the second end wall 17, coincides with the central axis of the circumferential wall 13. In this specification, the center of the first end wall 15 and the center of the second end wall 17 refer to the centroid positions of the first end wall 15 and the second end wall 17, respectively. In the illustrated embodiment, the first end wall 15 is a circular flat plate shape, the second end wall 17 is a hemispherical shape, and the circumferential side wall 13 is cylindrical. However, the shape of the circumferential side wall 13 is not limited to a cylindrical shape; it can be any shape, such as an elliptical cylinder, a triangular cylinder, or a polygonal cylinder, as long as it can generate a vortex flow within the vortex chamber 25. Similarly, the shape of the first end wall is not limited to a circular flat plate shape; it can be any shape, such as an elliptical flat plate shape, a triangular flat plate, or a polygonal flat plate, in accordance with the shape of the circumferential side wall 13. Furthermore, the shape of the second end wall 17 is not limited to a hemispherical shape; it can be any shape, such as a cone, an elliptical cone, a polygonal pyramidal shape, such as a triangular pyramid or a square pyramid, or a circular flat plate shape or a polygonal planar shape similar to the shape of the first end wall 15.

[0019] The inlet channel 19 is connected to an inlet opening 27 provided in the circumferential wall 13 and extends along the inlet channel central axis P1 perpendicular to the vortex chamber central axis O. The inlet channel central axis P1 extends so as to pass through the center of the cross-section of the inlet channel 19. A mixed fluid containing at least two or more types of fluids is supplied to the inlet channel 19. The outlet channel 21 is connected to an outlet opening 29 provided in the second end wall 17 and extends along the outlet channel central axis P2. The outlet channel central axis P2 extends so as to pass through the center of the cross-section of the outlet channel 21. The outlet channel 21 is configured to discharge the mixed fluid, which has been mixed within the vortex chamber 25. In the illustrated embodiment, the outlet channel central axis P2 extends perpendicular to the vortex chamber central axis O. However, the direction in which the central axis P2 of the outlet channel extends is not particularly limited, as long as fluid can be discharged from the vortex chamber 25. For example, the central axis P2 of the outlet channel may extend parallel to the central axis O of the vortex chamber. Also, in the illustrated embodiment, both the inlet channel 19 and the outlet channel 21 are made of circular pipes with a circular cross-section. However, the cross-sectional shape of the inlet channel 19 and the outlet channel 21 is not limited to a circular shape, and can be an elliptical or polygonal shape such as a square. Furthermore, in the illustrated embodiment, the inlet channel 19 is made of a straight circular pipe, but it may be made of other shapes such as a nozzle shape, as long as fluid can be introduced into the vortex chamber 25.

[0020] The inlet channel 19 is provided such that the central axis P1 of the inlet channel passes through an eccentric position away from the central axis O of the vortex chamber. Therefore, the fluid flowing in from the inlet channel 19 strikes the circumferential side wall 13 in the vortex chamber 25, flows along the circumferential side wall 13, generates a swirling flow, and becomes a vortex flow, which then flows towards the outlet channel 21 and flows out from the outlet channel 21. In order to facilitate the generation of a swirling flow, it is preferable that the inlet channel 19 is provided such that the fluid flowing into the vortex chamber 25 from the inlet channel 19 flows along the circumferential side wall 13.

[0021] In the illustrated embodiment, the inlet channel 19 extends tangentially to the cylindrical circumferential wall 13 and is connected to the circumferential wall 13 such that the central axis P1 of the inlet channel is parallel to the tangency, so that the fluid flows from the inlet channel 19 into the vortex chamber 25 substantially tangentially to the circumferential wall 13.

[0022] On the other hand, the outlet opening 29 to which the outlet passage 21 is connected can be provided at any position, as long as the fluid that flows into the vortex chamber 25 from the inlet passage 19 flows out from the outlet passage 21 after generating a vortex flow. That is, the outlet opening 29 only needs to be provided on the opposite side of the inlet opening 27 in the direction of the vortex chamber central axis O with respect to the projection 31, which will be described later. For example, the outlet opening 29 may be provided in the center of the second end wall 17, or it may be provided on the circumferential wall 13. When the outlet opening 29 is provided on the circumferential wall 13, it is preferable that it be provided in a region of the circumferential wall 13 adjacent to the second end wall 17 (preferably adjacent to the second end wall 17) in order to prevent the formation of a stagnant area.

[0023] When the outlet opening 29 is provided in the circumferential wall 13, it is preferable that the outlet flow path 21 extends tangentially to the cylindrical circumferential wall 13 and is connected to the outlet opening 29 such that the central axis P2 of the outlet flow path is parallel to the tangency. With this configuration, the vortex-forming fluid can flow smoothly out of the outlet flow path 21, and the occurrence of pressure loss can be suppressed.

[0024] In the illustrated embodiment, the outlet opening 29 is provided at the center, or top, of the hemispherical second end wall 17, and the outlet channel 21 extends from the outlet opening 29 along the outlet channel central axis P2 in a direction perpendicular to the vortex chamber central axis O. When the second end wall has a circular plate shape, the fluid flowing out of the vortex chamber 25 flows along the outlet channel central axis P2 in the outlet channel 21, as shown in Figure 2. In contrast, when the second end wall 17 has a hemispherical shape, as in the first embodiment, as shown in Figure 3, the fluid flowing out of the vortex chamber 25 gradually decreases its vortex radius towards the vortex chamber central axis O along the hemispherical second end wall 17, changes the direction of the vortex flow at the center of the hemispherical second end wall, and flows through the outlet channel 21 while forming a vortex around the outlet channel central axis P2. This has the advantage of making it possible to obtain a mixing effect due to the vortex flow even in the outlet channel 21. Note that in Figures 2 and 3, the protrusion 31 has been omitted for simplification.

[0025] The confluence section 23 is configured to combine different types of fluids supplied from at least two fluid supply channels connected to different fluid sources and allow them to flow into the vortex chamber 25 through the inlet opening 27 via the inlet channel 19. The mixed fluid, consisting of different types of fluids combined in the confluence section 23, is supplied to the inlet channel 19. In the illustrated first embodiment, the confluence section 23 is composed of a T-shaped channel, in which one end of a straight main channel 23a, one end of which is connected to the inlet channel 19, is connected to one end of a sub-channel 23b. Fluid A is supplied from the other end of the main channel 23a and fluid B is supplied from the other end of the sub-channel 23b, so that fluid A and fluid B are combined in the confluence section 23 to generate a mixed fluid. The shape of the confluence section 23 is not limited to a T shape, and may be a Y shape, for example. Furthermore, two or more sub-channels 23b may be connected to the main channel 23a, and three or more types of fluids may be combined at the confluence section 23 to form a mixed fluid. The main channel 23a and sub-channels 23b constituting the confluence section 23 are preferably straight circular pipes with a circular cross-section, but are not limited to circular pipes and can be pipes with any cross-sectional shape. Furthermore, the pipe diameters (inner diameters) of the main channel 23a and sub-channels 23b are preferably the same, but the pipe diameter (inner diameter) of the sub-channel 23b may be smaller than the pipe diameter (inner diameter) of the main channel 23a.

[0026] In the vortex-type fluid mixer 111, different types of fluids, i.e., mixed fluids, that merge at the confluence section 23 are supplied to the inlet channel 19 and flow into the vortex chamber 25 via the inlet channel 19. Furthermore, the central axis P1 of the inlet channel passes through an eccentric position away from the central axis O of the vortex chamber, and the central axis P2 of the outlet channel extends through a position away from the central axis P1 of the inlet channel. Therefore, within the vortex chamber 25, the fluid flowing in from the inlet channel 19 strikes the circumferential side wall 13 and flows along the circumferential side wall 13, generating a swirling flow, which becomes a vortex flow around the central axis O of the vortex chamber and flows towards the outlet channel 21, from which it flows out. In other words, the mixed fluid, which contains different types of fluids and flows in from the inlet channel 19, forms a vortex flow within the vortex chamber 25 before flowing out from the outlet channel 21. Therefore, the mixed fluid flowing in from the inlet channel 19 can reduce the variation in the concentration of different types of fluids (unevenness in the concentration distribution) due to the stirring action of the vortex flow, and flows out from the outlet channel 21 with reduced concentration variation.

[0027] The vortex-type fluid mixer 111 further includes a projection 31 that protrudes toward the vortex chamber central axis O from the circumferential side wall 13 toward the second end wall 17 toward the inlet opening 27, and the projection 31 forms a throttling portion within the vortex chamber 25 between the first end wall 15 and the second end wall 17, which is narrower radially (in the direction perpendicular to the vortex chamber central axis O) than the rest of the circumferential side wall 13. In the first embodiment, the vortex-type fluid mixer 111 includes an annular projection 31. Preferably, the opening area of ​​the smallest opening in the throttling portion formed by the projection 31 (the smallest cross-sectional area of ​​the vortex chamber surface perpendicular to the vortex chamber central axis O at the smallest opening in the throttling portion) is larger than the cross-sectional area of ​​the inlet flow path 19. This prevents the throttling portion formed by the projection 31 from causing a reduction in the flow rate of the vortex-type fluid mixer 111.

[0028] In the vortex-type fluid mixer 111 according to the first embodiment, the projection 31 is formed by narrowing the circumferential side wall 13 toward the central axis O of the vortex chamber. However, the method of forming the projection 31 is not limited as long as a narrowing portion is formed within the vortex chamber 25. For example, the projection 31 may be formed by providing a raised portion on the inner circumferential surface of the circumferential side wall 13 that protrudes toward the central axis O of the vortex chamber while maintaining the shape of the outer circumferential surface of the circumferential side wall 13.

[0029] In the vortex-type fluid mixer 111 according to the first embodiment, the mixed fluid created by the confluence section 23 is supplied to the inlet channel 19. However, if a fluid containing two or more different fluids is supplied to the inlet channel 19, the mixed fluid is not limited to that created by the confluence section 23. For example, the mixed fluid may be roughly mixed in a mixing tank or the like.

[0030] In the vortex-type fluid mixer 111, the stirring action of the swirling flow, or vortex flow, generated within the vortex chamber 25 is used to mix a mixed fluid containing different types of fluids, thereby reducing concentration unevenness. The mixed fluid flows mainly along the circumferential side wall 13 within the vortex chamber 25. Therefore, if the circumferential side wall 13 is a simple cylindrical shape and no projection 31 is provided, the stirring effect will be smaller on the side closer to the vortex chamber's central axis O (hereinafter also referred to as the inner side) compared to the side closer to the circumferential side wall 13 (hereinafter also referred to as the outer side), resulting in radial mixing unevenness and a tendency for unevenness (concentration variation) in the concentration distribution of the mixed fluid between the outer and inner sides of the vortex chamber 25. However, in the vortex-type fluid mixer 111, a projection 31 is provided between the inlet opening 27 and the second end wall 17 in the direction of the vortex chamber's central axis O, forming a throttling section. In other words, the projection 31 is provided along the path where a mixed fluid containing different types of fluids flows in a vortex from the inlet channel 19 to the outlet channel 21 within the vortex chamber 25, forming a vortex flow. As a result, the mixed fluid, which mainly flows along the circumferential side wall 13 and becomes a swirling flow, flows through the constricted section of the vortex chamber 25 before being discharged from the outlet channel 21. At the constricted section, the projection 31 reduces the radial dimension of the vortex chamber 25 (the direction perpendicular to the vortex chamber's central axis O). Therefore, when the swirling flow reaches the constricted section, it generates a flow in the radial direction toward the vortex chamber's central axis O, suppressing radial mixing unevenness. As a result, this has the effect of reducing variations in the radial concentration of the mixed fluid within the vortex chamber 25 (unevenness in concentration distribution).

[0031] As long as the projection 31 forms a narrower constriction in the vortex chamber 25 than the portion closer to the inlet opening 27, it is possible to generate a flow radially toward the central axis O of the vortex chamber, thereby reducing the aforementioned concentration variation (unevenness in concentration distribution). Therefore, as long as the projection 31 protrudes toward the central axis O of the vortex chamber so as to form a constriction, the shape of the projection 31 is not limited, and it does not need to be annular.

[0032] The vortex-type fluid mixer 111 according to the first embodiment is merely one embodiment of the present invention, and the present invention is not limited to the configuration of the first embodiment. Hereinafter, other embodiments of vortex-type fluid mixers according to the present invention will be described with reference to Figures 2 to 6.

[0033] In the vortex-type fluid mixer 211 according to the second embodiment, the vortex-type fluid mixer 311 according to the third embodiment, the vortex-type fluid mixer 411 according to the fourth embodiment, the vortex-type fluid mixer 511 according to the fifth embodiment, and the vortex-type fluid mixer 611 according to the sixth embodiment, as shown in Figures 2 to 6, the same reference numerals are used for components that are common to the vortex-type fluid mixer 111 according to the first embodiment shown in Figure 1. Furthermore, components with the same reference numerals have similar configurations. Therefore, the following description of components common to the vortex-type fluid mixer 111 according to the first embodiment will be omitted.

[0034] In the first embodiment of the vortex-type fluid mixer 111 shown in Figure 1, an annular projection 31 extending circumferentially around the central axis O of the vortex chamber is provided on the circumferential side wall 13, and the smallest opening of the throttling portion formed by the projection 31, i.e., the ridge line connecting the tops of the inner circumferential surface of the throttling portion, extends in a circular shape when viewed in the direction of the central axis O of the vortex chamber. However, the annular projection 31 may be formed such that the smallest opening of the throttling portion has any arbitrary shape when viewed in the direction of the central axis O of the vortex chamber, such as an elliptical shape, a polygonal shape, or a shape that combines straight lines and curves in an annular shape. Furthermore, as described above, the projection 31 does not need to extend in an annular shape; it is sufficient that a throttling portion is formed in which at least a part of the circumferential side wall 13 is tapered in the radial direction. For example, the projection 31 may be provided only on a part of the circumferential side wall 13, or multiple projections 31 may be provided adjacent to or spaced apart from each other in the circumferential direction. Specifically, when the projection 31 is provided on only a part of the circumferential side wall 13, or when multiple projections 31 are provided in the circumferential direction of the circumferential side wall 13, the edges of each projection 31 may extend in an arc shape, a straight line shape, or a shape formed by connecting multiple straight lines when viewed in the direction of the vortex chamber central axis O. Furthermore, when multiple projections 31 are provided adjacent to each other in the circumferential direction, the smallest opening of the constricted portion formed by the projections 31 may have a polygonal shape such as a triangle or square, or a shape formed by combining straight lines and curves in an annular manner when viewed in the direction of the vortex chamber central axis O. In addition, the highest part of the projection 31 may extend linearly or planarly in the circumferential direction.

[0035] Specifically, as shown in Figures 4A to 4C, the vortex-type fluid mixer 211 according to the second embodiment, three identically shaped protruding elements 31a', each with a straight ridge at its top, are provided adjacent to each other in the circumferential direction on the circumferential side wall 13 to form an annular projection 31', and the ridge connecting the tops of the inner circumferential surface of the throttling portion, i.e., extends in a triangular shape when viewed in the direction of the vortex chamber central axis O. Alternatively, as shown in Figures 5A to 5C, the vortex-type fluid mixer 311 according to the third embodiment, a projection 31'' with an arc-shaped ridge at its top is provided only on a part of the circumferential side wall 13, and the ridge connecting the tops of the inner circumferential surface of the throttling portion, i.e., extends in an arc shape when viewed in the direction of the vortex chamber central axis O.

[0036] Furthermore, in the embodiment shown in Figure 1, the first end wall 15 has a circular flat plate shape, and the second end wall 17 has a hemispherical shape. However, as described above, if the mixed fluid forms a vortex or swirling flow within the vortex chamber 25 and a projection 31 is provided within the vortex chamber 25, it is possible to obtain the effect of reducing variations in concentration and unevenness in concentration distribution. Therefore, the first end wall 15 and the second end wall 17 are not limited to the shapes of the first end wall 15 and the second end wall 17 of the vortex-type fluid mixer 111 of the first embodiment.

[0037] The first end wall 15 may have a hemispherical shape like the second end wall 17, or it may have a conical shape, an elliptical cone shape, a polygonal pyramidal shape, or a polygonal planar shape. Alternatively, as in the vortex-type fluid mixer 411 according to the fourth embodiment shown in Figure 6, the second end wall 17' may have a conical shape. In this case, it is preferable that at least a portion of the end of the outlet channel 21 is connected to the side surface of the cone, that is, at least a portion of the outlet opening 29 is formed on the side surface of the cone. By connecting the outlet channel 21 in this way, the mixed fluid that forms a swirling flow along the conical surface can flow smoothly into the outlet channel 21, thereby reducing pressure loss. As shown in the fifth embodiment of the vortex-type fluid mixer 511 in Figure 7, the second end wall 17" may have a circular flat plate shape. In the fifth embodiment of the vortex-type fluid mixer 511 shown in Figure 7, the outlet channel 21 extends from the circumferential wall 13 such that the outlet channel central axis P2 extends perpendicular to the vortex chamber central axis O. In this case, in order to prevent stagnation from occurring on the side of the second end wall 17" rather than the outlet opening 29 in the direction of the vortex chamber central axis O, it is preferable that the outlet opening 29 be provided adjacent to the second end wall 17" on the circumferential wall 13. Also, if the second end wall 17" has a circular flat plate shape, the outlet channel 21 may be configured such that the outlet channel central axis P2 extends parallel to, preferably coaxially with, the vortex chamber central axis O.

[0038] Furthermore, as shown in the sixth embodiment of the vortex-type fluid mixer 611 in Figure 8, the first end wall may be configured with a diaphragm 15'. In the sixth embodiment, the diaphragm 15' is driven by a drive unit (not shown) to move closer to and away from the second end wall 17 in the direction of the central axis O of the vortex chamber, thereby increasing or decreasing the volume of the vortex chamber 25 and adjusting the fluid flow velocity within the vortex chamber 25. Various drive methods can be employed for the drive unit, such as manual, air-driven, or electric. By adjusting the fluid flow velocity within the vortex chamber 25, it becomes possible to perform more appropriate mixing with less concentration unevenness depending on the type of fluid being mixed.

[0039] The following describes the results of a numerical simulation analysis to verify the effect of the vortex fluid mixer according to the present invention. In the following description, for the sake of clarity, the same reference numerals are used for components common to the components of the vortex fluid mixer 111 in the vortex fluid mixer model used in the numerical simulation. Furthermore, in order to clarify the effect of the projection 31, in the vortex fluid mixer model used in this numerical simulation, the passive scalar of the mixed fluid is determined in a cross section perpendicular to the central axis O of the vortex chamber at a measurement position X located in the vortex chamber 25, which is on the second end wall 17 side of the projection 31 and on the first end wall 15 side of the second end wall 17. Note that the numerical simulation was performed assuming that there is no influence from the outlet flow path 21 at measurement position X.

[0040] First, we will explain the results of a numerical simulation to verify the effect of the projection 31 of the vortex-type fluid mixer 111 according to the present invention. In the numerical simulation, a vortex-type fluid mixer model M1 equipped with a projection 31 having the configuration and dimensions shown in Figures 9 and 10, and a vortex-type fluid mixer model M2 without a projection having the configuration and dimensions shown in Figures 11 and 12 were used. More specifically, in both the vortex fluid mixer model M1 with a projection 31 and the vortex fluid mixer model M2 without a projection, the vortex chamber 25 has a roughly cylindrical shape with a diameter of 12 mm and a height of 30 mm. A circular inlet channel 19 with a diameter of 4 mm is connected to the circumferential wall 13 such that the central axis P1 of the inlet channel passes 3.5 mm from the center of the vortex chamber 25 in a direction perpendicular to the central axis O of the vortex chamber and 5.5 mm from the first end wall in the direction of the central axis O of the vortex chamber. The inlet channel 19 extends to a position 20 mm away from the central axis O of the vortex chamber. Here, the "height" of the vortex chamber 25 refers to the length from the first end wall 15 in the direction of the central axis O of the vortex chamber to the measurement position X (more specifically, measurement position X1 in the vortex fluid mixer model M1 and measurement position X2 in the vortex fluid mixer model M2). In the vortex-type fluid mixer model M1, an annular projection 31 is provided on the circumferential side wall 13, projecting toward the vortex chamber central axis O in a semicircular shape with a diameter of 6 mm, centered at a position 4 mm away from the outer surface of the inlet channel 19 (i.e., 11.5 mm from the first end wall 15) in the direction of the vortex chamber central axis O. In contrast, in the vortex-type fluid mixer model M2, the circumferential side wall 13 does not have the above-described projection, and the circumferential side wall 13 has a cylindrical shape.

[0041] Furthermore, in numerical simulations to verify the effect of the protrusion 31, white water was supplied at a rate of 500 mL / min and black water at a rate of 500 mL / min to the right end of the inlet channel 19 in the vortex-type fluid mixer model M1 shown in Figures 9 and 10 and the vortex-type fluid mixer model M2 shown in Figures 11 and 12. The mixed fluid containing white water and black water was mixed in the vortex chamber 25 to form a mixed fluid. In the vortex-type fluid mixer model M1, the way in which white water and black water mixed was evaluated using passive color as an indicator at the cross-section of the vortex chamber 25 at measurement position X1 (a cross-section perpendicular to the central axis O of the vortex chamber), and in the vortex-type fluid mixer model M2, the cross-section of the vortex chamber 25 at measurement position X2. Passive color is a surrogate index of concentration in relation to the color of the mixed fluid, where white is considered as 1 (concentration of white water is 100%) and black as 0 (concentration of black water is 0%). Furthermore, to evaluate the degree of uneven mixing between white water and black water, the cross-sections at measurement positions X1 and X2 are divided into multiple regions, the passive scalar is determined in each region, and the degree of uneven mixing is expressed using the difference between the maximum and minimum values ​​of the passive scalar obtained in each region of the cross-section.

[0042] Figure 13 is a bar graph comparing the degree of mixing unevenness at measurement position X1 for a vortex-type fluid mixer model M1 equipped with a projection 31 and the degree of mixing unevenness at measurement position X2 for a vortex-type fluid mixer model M2 without a projection. In Figure 13, the vertical axis represents the difference between the maximum and minimum values ​​of the passive scalar, which is an indicator of the degree of mixing unevenness. The results for the vortex-type fluid mixer model M1 are shown on the left, and the results for the vortex-type fluid mixer model M2 are shown on the right. As can be seen from Figure 13, compared to the case of the vortex-type fluid mixer model M2 without a projection, the difference between the maximum and minimum values ​​of the passive scalar at measurement position X1 is smaller for the vortex-type fluid mixer model M1 equipped with a projection 31, indicating less mixing unevenness. This indicates that the variation in concentration (unevenness of concentration distribution) at radial positions is reduced. Therefore, this numerical simulation confirmed that using the vortex-type fluid mixer 111 has the effect of eliminating radial concentration variations (unevenness in concentration distribution), that is, the effect of homogenizing the radial concentration.

[0043] Next, we will explain the results of a numerical simulation to verify the effect of the shape of the protrusions 31' and 31'' of the vortex-type fluid mixers 211 and 311 according to the present invention. In the numerical simulation, a vortex-type fluid mixer model M3 having the configuration and dimensions shown in Figures 14 to 16, and a vortex-type fluid mixer model M4 having the configuration and dimensions shown in Figures 17 to 19 were used. For comparison, a vortex-type fluid mixer model M2 without protrusions, having the configuration and dimensions shown in Figures 11 and 12 described above, was also used. In the vortex-type fluid mixer model M3, the vortex-type fluid mixer 211 according to the second embodiment shown in Figures 4A to 4C Similarly, three identical protruding elements 31a', each with a straight ridge at its top, are provided adjacent to each other in the circumferential direction on the circumferential side wall 13 to form an annular projection 31', and the smallest opening of the throttling portion (i.e., the ridge connecting the tops of the inner circumferential surface of the throttling portion) has a triangular shape when viewed in the direction of the vortex chamber central axis O. Furthermore, in the vortex-type fluid mixer model M4, similar to the vortex-type fluid mixer 311 according to the third embodiment shown in Figures 5A to 5C, a protruding portion 31'' with an arc-shaped ridge at its top is provided only on a part of the circumferential side wall 13, and the smallest opening of the throttling portion (i.e., the ridge connecting the tops of the inner circumferential surface of the throttling portion) has an arc shape when viewed in the direction of the vortex chamber central axis O.

[0044] Specifically, in common to the vortex fluid mixer model M3 and the vortex fluid mixer model M4, the vortex chamber 25 has a substantially cylindrical shape with a diameter of 12 mm and a height of 30 mm. The inlet flow path central axis P1 passes through a position that is 3.5 mm away from the center of the vortex chamber 25 in a direction perpendicular to the vortex chamber central axis O and 5.5 mm away from the first end wall in the direction of the vortex chamber central axis O. A circular pipe-shaped inlet flow path 19 with a diameter of 4 mm is connected to the circumferential side wall 13 and extends to a position 20 mm away from the vortex chamber central axis O. Here, the "height" of the vortex chamber 25 means the length from the first end wall 15 in the direction of the vortex chamber central axis O to the measurement position X (specifically, the measurement position X3 in the vortex fluid mixer model M3 and the measurement position X4 in the vortex fluid mixer model M4). In the vortex fluid mixer model M3, three protruding elements 31a' that protrude linearly toward the vortex chamber central axis O and are adjacent to each other in the circumferential direction are provided so as to form a semi-circular shape with a diameter of 7 mm at the position with the largest protrusion amount centered at a position 11.5 mm away from the first end wall 15 in the direction of the vortex chamber central axis O on the circumferential side wall 13, forming an annular protrusion 31'. In the vortex fluid mixer model M4, a protrusion 31" that protrudes toward the vortex chamber central axis O so as to form an arc shape with a diameter of 7 mm centered at a position 11.5 mm away from the first end wall 15 in the direction of the vortex chamber central axis O on the circumferential side wall 13 and extends in an arc shape so as to be connected to the circumferential side wall 13 at a position 3 mm away from the vortex chamber central axis O in the direction of the inlet flow path central axis P1 is provided. Since the vortex fluid mixer model M2 is as described above, the description is omitted here.

[0045] In this numerical simulation, white water was supplied at a rate of 500 mL / min and black water at a rate of 500 mL / min to the right end of the vortex fluid mixer models M2, M3, and M4 in the diagram, and the mixed fluid containing white water and black water was mixed in the vortex chamber 25 to form a mixed fluid. The mixing of white water and black water was evaluated using passive scalar as an indicator at the cross-section of the vortex chamber 25 at measurement position X2 (a cross-section perpendicular to the central axis O of the vortex chamber) in the vortex fluid mixer model M2, at measurement position X3 (a cross-section perpendicular to the central axis O of the vortex chamber) in the vortex fluid mixer model M3, and at measurement position X4 in the vortex fluid mixer model M4. To evaluate the degree of uneven mixing between white water and black water, the cross-sections at measurement positions X2, X3, and X4 are divided into multiple regions. Passive scalars are determined in each region, and the degree of uneven mixing between white water and black water is expressed using the difference between the maximum and minimum values ​​of the passive scalars obtained in each region of the cross-section.

[0046] Figure 20 is a bar graph comparing the degree of mixing unevenness at measurement position X3 for vortex-type fluid mixer model M3, where the minimum opening of the throttling portion formed by the projection 31' is triangular when viewed in the direction of the vortex chamber central axis O; the degree of mixing unevenness at measurement position X4 for vortex-type fluid mixer model M4, where the minimum opening of the throttling portion formed by the projection 31'' is arc-shaped when viewed in the direction of the vortex chamber central axis O; and the degree of mixing unevenness at measurement position X2 for vortex-type fluid mixer model M2, which has no projections. In Figure 20, the vertical axis is the difference between the maximum and minimum values ​​of the passive scalar as an indicator of the degree of mixing unevenness, with the results for vortex-type fluid mixer model M3 on the left, the results for vortex-type fluid mixer model M4 in the center, and the results for vortex-type fluid mixer model M4 on the right. The results for Model M2 are shown. As can be seen from Figure 20, compared to the case of vortex-type fluid mixer Model M2, which does not have protrusions, the difference between the maximum and minimum values ​​of the passive scalar at the measurement position X1 is smaller in vortex-type fluid mixer Models M3 and M4, and the mixing unevenness is reduced. This indicates that the variation in concentration at radial positions (unevenness in concentration distribution) is reduced. Therefore, regardless of the shape of the protrusions, if a constricted section is formed where the cross-section perpendicular to the central axis O of the vortex chamber is smaller than that of other parts of the vortex chamber 25, the effect of eliminating the variation in radial concentration (unevenness in concentration distribution), i.e., the effect of homogenizing the radial concentration, is obtained, as confirmed by this numerical simulation.

[0047] Although the vortex-type fluid mixers 111, 211, 311, 411, 511, and 611 according to the present invention have been described above with reference to the illustrated embodiments, the present invention is not limited to the illustrated embodiments. For example, in the illustrated embodiments, a cylindrical vortex chamber 25 is used, but an elliptical or polygonal cylindrical vortex chamber can also be used as long as a vortex flow can be generated within the vortex chamber 25. Also, in the illustrated embodiments, a projection is provided at one position in the direction of the central axis of the vortex chamber, but multiple projections may be provided at different positions.

[0048] 13 Peripheral wall 15 First end wall 15' Diamond 17' Second end wall 17" Second end wall 19 Inlet flow path 21 Outlet flow path 25 Vortex chamber 31 Protrusion 31' Protrusion 31a' Protrusion element 31" Protrusion 111 Vortex fluid mixer 211 Vortex fluid mixer 311 Vortex fluid mixer 411 Vortex fluid mixer 511 Vortex fluid mixer 611 Vortex fluid mixer

Claims

1. A vortex-type fluid mixer for mixing two or more fluids using a vortex flow, comprising: a vortex chamber defined by a cylindrical circumferential wall extending along the central axis of the vortex chamber and a first end wall and a second end wall provided at both ends of the circumferential wall and facing each other; an inlet passage connected to an inlet opening provided in the circumferential wall and extending along an inlet passage central axis passing away from the central axis of the vortex chamber; and an outlet passage connected to an outlet opening provided in the second end wall or in an adjacent area of ​​the circumferential wall, wherein a projection is provided in the circumferential wall between the inlet opening and the second end wall in the direction of the central axis of the vortex chamber, and the projection forms a throttling portion between the first end wall and the second end wall.

2. The vortex-type fluid mixer according to claim 1, wherein the projection is an annular projection.

3. The vortex-type fluid mixer according to claim 2, wherein the smallest opening of the throttling portion has a circular, elliptical, or polygonal shape when viewed in the direction of the central axis of the vortex chamber.

4. The vortex-type fluid mixer according to claim 1, wherein the projection is provided only on a part of the circumferential side wall.

5. The vortex-type fluid mixer according to claim 4, wherein the ridge of the projection has an arc shape or a shape formed by connecting multiple straight lines when viewed in the direction of the central axis of the vortex chamber.

6. The vortex-type fluid mixer according to claim 1, wherein the protrusions are provided at multiple positions in the direction of the central axis of the vortex chamber.

7. The vortex-type fluid mixer according to any one of claims 1 to 6, wherein the second end wall has a weight-like or hemispherical shape.

8. The vortex-type fluid mixer according to any one of claims 1 to 6, wherein the cross-sectional area of ​​the smallest opening of the throttling portion is larger than the cross-sectional area of ​​the inlet flow path.

9. The vortex-type fluid mixer according to any one of claims 1 to 6, wherein the diameter of the vortex chamber is greater than the diameter of the inlet channel.

10. The vortex fluid mixer according to any one of claims 1 to 6, wherein the first end wall is formed by a diaphragm that is deformable in the direction of the central axis of the vortex chamber.

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