Mixing device

Abstract

A mixing device disclosed in the present specification comprises: a first inflow part into which a first fluid flows; a second inflow part into which a second fluid flows; an outflow part from which a mixed fluid flows out; a plurality of first fluid passages each of which communicates between the first inflow part and the outflow part; and a plurality of second fluid passages each of which communicates between the second inflow part and each of the plurality of first fluid passages. Each of the plurality of first fluid passages has a diameter-decreasing passage where the passage decreases in diameter, and a diameter-increasing passage which is provided downstream of the diameter-decreasing passage and where the passage increases in diameter. Each of the plurality of second fluid passages is formed in a straight line from the upstream end to the downstream end, and some of the plurality of second fluid passages are disposed such that the upstream end is positioned in a first direction when viewed from the downstream end, the remainder being disposed such that the upstream end is positioned in the first direction or in a second direction different from the first direction when viewed from the downstream end.

Description

mixing device

[0001] The technology disclosed in this specification relates to a mixing device.

[0002] Japanese Patent Laid-Open Publication No. 8-131800 discloses a mixing device that mixes a first fluid with a second fluid to produce a mixed fluid. The mixing device includes a first inlet into which the first fluid flows, a second inlet into which the second fluid flows, an outlet from which the mixed fluid flows, and a passage member arranged such that one end faces the first inlet, the other end faces the outlet, and the side surface between the one end and the other end faces the second inlet. The passage member has a plurality of first fluid flow paths, each communicating between the first inlet and the outlet, and a plurality of second fluid flow paths, each communicating between the second inlet and each of the plurality of first fluid flow paths. The plurality of first fluid flow paths includes at least three first fluid flow paths. Each of the plurality of first fluid flow paths includes a reduced-diameter flow path whose diameter decreases from the first inlet to the outlet, and an increased-diameter flow path located downstream of the reduced-diameter flow path and whose diameter increases from the first inlet to the outlet. Each of the plurality of second fluid flow paths has a downstream end communicating with the first fluid flow path and is formed linearly from its upstream end to its downstream end. Each of the plurality of second fluid flow paths is arranged radially with respect to a central axis in the flow direction of the plurality of first fluid flow paths.

[0003] In the mixing device disclosed in JP-A-8-131800, multiple second fluid flow paths are arranged radially relative to the central axis of the first fluid flow path. This poses a problem in terms of processability when manufacturing the passage member. For example, when manufacturing the passage member by injection molding using resin, separate molds corresponding to the multiple second fluid flow paths must be prepared for demolding after molding. This specification provides a technology that can further improve the processability of the passage member.

[0004] A first aspect of the mixing device disclosed in this specification mixes a first fluid with a second fluid to produce a mixed fluid. The mixing device includes a first inlet into which the first fluid flows, a second inlet into which the second fluid flows, an outlet from which the mixed fluid flows, and a passage member arranged such that one end faces the first inlet, the other end faces the outlet, and a side surface between the one end and the other end faces the second inlet. The passage member has a plurality of first fluid flow paths, each communicating between the first inlet and the outlet, and a plurality of second fluid flow paths, each communicating between the second inlet and each of the plurality of first fluid flow paths. The plurality of first fluid flow paths includes at least three first fluid flow paths. Each of the plurality of first fluid flow paths includes a reduced-diameter flow path whose flow path diameter decreases from the first inlet side toward the outlet side, and an increased-diameter flow path provided downstream of the reduced-diameter flow path and whose flow path diameter increases from the first inlet side toward the outlet side. Each of the plurality of second fluid flow paths has a downstream end communicating with the first fluid flow path and is formed linearly from its upstream end to its downstream end. Some of the plurality of second fluid flow paths are arranged so that their upstream ends are located in a first direction as viewed from their downstream ends. The remainder of the plurality of second fluid flow paths are arranged so that their upstream ends are located in the first direction or a second direction different from the first direction as viewed from their downstream ends.

[0005] According to the above configuration, for example, when the passage member is manufactured by injection molding using resin, even if the passage member has three or more first fluid flow paths, it is only necessary to prepare one or two molds corresponding to each of the plurality of second fluid flow paths for demolding after molding. According to the above configuration, the processability of the passage member can be further improved.

[0006] In a second aspect, in the mixing device of the first aspect, the plurality of second fluid flow paths may be arranged along a plane perpendicular to the flow direction of the plurality of first fluid flow paths.

[0007] According to the above configuration, for example, when manufacturing the passage member by injection molding using resin, it is possible to perform demolding of a mold corresponding to the plurality of second fluid flow paths without using a slide mechanism that slides the passage member in the flow direction of the plurality of first fluid flow paths. This makes it possible to suppress the complexity of the mold configuration. According to the above configuration, it is possible to further improve the processability of the passage member.

[0008] In a third aspect, in the mixing device of the second aspect, the remaining of the plurality of second fluid flow paths may be arranged so that their upstream ends are positioned in the second direction when viewed from the downstream end, and the second direction may be the opposite direction to the first direction.

[0009] According to the above configuration, for example, when manufacturing the passage member by injection molding using resin, the removal direction of the mold corresponding to a portion of the plurality of second fluid flow paths (i.e., the first direction) can be opposite to the removal direction of the mold corresponding to the remainder of the plurality of second fluid flow paths (i.e., the second direction). This allows the mold corresponding to a portion of the plurality of second fluid flow paths to be removed symmetrically in the first direction and the mold corresponding to the remainder of the plurality of second fluid flow paths to be removed in the second direction while holding the passage member in the same orientation, thereby forming a mold with excellent demoldability. According to the above configuration, the processability of the passage member can be further improved.

[0010] In a fourth aspect, in the mixing device of the third aspect, the first fluid flow paths with which some of the plurality of second fluid flow paths communicate may be arranged at a position where a distance to the side surface in the first direction is equal to or less than a distance to the side surface in the second direction. The first fluid flow paths with which the remainder of the plurality of second fluid flow paths communicate may be arranged at a position where a distance to the side surface in the second direction is equal to or less than a distance to the side surface in the first direction.

[0011] According to the above configuration, the length of each of the plurality of second fluid flow paths can be shortened. This reduces pressure loss when the second fluid passes through the plurality of second fluid flow paths, allowing a larger amount of second fluid to flow in. Furthermore, for example, when manufacturing the passage member by injection molding using resin, the length of the pin-shaped mold corresponding to the plurality of second fluid flow paths can be shortened, thereby preventing damage to the mold during manufacturing of the passage member.

[0012] In a fifth aspect, in the mixing device of the third or fourth aspect, the mixing device may further include a case member that houses the passage member. The case member may include a supply port that supplies the second fluid to the second inlet portion. The supply port may be arranged to face the side surface of the passage member in a direction perpendicular to the first direction and the second direction, at a center position between an end of the side surface of the passage member in the first direction and an end of the side surface of the passage member in the second direction.

[0013] According to the above configuration, it is possible to reduce the unevenness in the distance from the supply port to the upstream ends of the second fluid flow paths, so that the second fluid flowing in from the second inlet portion can be made to flow evenly into some of the second fluid flow paths and the remaining second fluid flow paths.

[0014] In a sixth aspect, in the mixing device of any one of the second to fifth aspects, the side surface of the passage member may include an expanded diameter section whose diameter expands from the first inlet side toward the outlet side. Each of the plurality of first fluid flow paths may further include a same-diameter flow path that communicates the reduced-diameter flow path and the expanded-diameter flow path and has a constant flow path diameter. The expanded-diameter flow path and the same-diameter flow path of each of the plurality of first fluid flow paths may be disposed inside the expanded diameter section. A downstream end of each of the plurality of second fluid flow paths may communicate with the same-diameter flow path of the first fluid flow path.

[0015] According to the above configuration, the same-diameter flow path has the smallest diameter among the first fluid flow paths and is therefore the flow path that is most depressurized. This further improves the suction effect of the second fluid into the second fluid flow path connected to the same-diameter flow path. Note that when the downstream end of the second fluid flow path is connected to the same-diameter flow path, the second fluid flow path is likely to be longer than when the downstream end of the second fluid flow path is connected to a reduced-diameter flow path or an expanded-diameter flow path. However, according to the above configuration, an expanded-diameter portion is formed on the side surface of the passage member, and the same-diameter flow path and the expanded-diameter flow path are disposed inside the expanded-diameter portion. This allows the length of the second fluid flow path to be shorter than when the diameter of the side surface of the passage member is constant. Therefore, the length of the second fluid flow path can be shortened while improving the suction effect of the second fluid. This reduces pressure loss in the second fluid flow path and allows more second fluid to flow in. Furthermore, for example, when manufacturing the passage member by injection molding using resin, the length of the pin-shaped mold corresponding to the multiple second fluid flow paths can be shortened, thereby preventing damage to the mold forming the second fluid flow paths during manufacturing the passage member.

[0016] FIG. 1 is an overall perspective view of a mixing device 2 of an embodiment; FIG. 2 is a longitudinal sectional view of a mixing device 2 of an embodiment; FIG. 3 is an overall perspective view of a passage member 10 of an embodiment, viewed from the downstream side; FIG. 4 is a cross sectional view of a location where a second fluid flow path 14 is arranged in the mixing device 2 of the embodiment; FIG. 5 is a longitudinal sectional view of a passage member 10 of a modified example; FIG. 6 is a cross sectional view of a location where a second fluid flow path 14 is arranged in a passage member 10 of another modified example; and FIG. 7 is a cross sectional view of a location where a second fluid flow path 14 is arranged in a mixing device 2 of yet another modified example.

[0017] Representative, non-limiting embodiments of the present disclosure are described in detail below with reference to the drawings. This detailed description is intended simply to provide those skilled in the art with details for implementing preferred embodiments of the present teachings and is not intended to limit the scope of the present disclosure. Furthermore, the additional features and teachings disclosed can be used separately or in conjunction with other features and teachings to provide further improved mixing devices and methods of using and manufacturing the same.

[0018] Furthermore, the combinations of features and steps disclosed in the following detailed description are not essential to practicing the present disclosure in its broadest sense, but are presented solely to specifically illustrate exemplary embodiments of the present disclosure. Furthermore, the various features of the following exemplary embodiments, as well as the various features of the various independent and dependent claims, do not necessarily have to be combined in the exact embodiments described herein, or in the exact order listed, to provide additional and useful embodiments of the present teachings.

[0019] All features described in this specification and / or claims are intended to be disclosed individually and independently of one another as limitations to the specific features described in the original disclosure and claims, apart from the configuration of features described in the examples and / or claims. Furthermore, all numerical ranges and group or aggregate descriptions are intended to disclose intermediate configurations thereof as limitations to the specific features described in the original disclosure and claims.

[0020] (Configuration of Mixing Device 2) The mixing device 2 shown in FIG. 1 includes a case member 100, an inlet member 102, and an outlet member 104. The case member 100 has a generally cylindrical shape centered on a central axis A. The case member 100 includes a supply section 106 that protrudes outward. An inlet 102a is formed in the inlet member 102. An outlet 104a is formed in the outlet member 104. An inlet 106a and a supply port 106b are formed in the supply section 106. The inlet 106a is an opening provided on the outer surface of the supply section 106, and the supply port 106b is an opening provided on the inner surface 18 (see FIG. 2) of the case member 100, and the inlet 106a and the supply port 106b are in communication with each other. The mixing device 2 mixes a first fluid (e.g., water) supplied from the outside via the inlet 102a with a second fluid (e.g., air) supplied from the outside via the inlet 106a, and discharges the mixed fluid (e.g., a fluid obtained by mixing water with air) to the outside via the outlet 104a.

[0021] The entrance member 102 is attached to one end of the case member 100. A plurality of screw bosses 100a are formed at one end of the case member 100. A plurality of screw receiving portions 102b are formed in the entrance member 102 corresponding to the plurality of screw bosses 100a. The entrance member 102 is fixed to the case member 100 by passing a plurality of screws 108 through the corresponding screw receiving portions 102b and threading them into the corresponding screw bosses 100a. A seal member 20c (see FIG. 2) is disposed at the connection point between the case member 100 and the entrance member 102, and the connection point between the case member 100 and the entrance member 102 is sealed by the seal member 20c.

[0022] The outlet member 104 is attached to the other end of the case member 100. A plurality of screw bosses 100b are formed at the other end of the case member 100. A plurality of screw receiving portions 104b are formed in the outlet member 104 corresponding to the plurality of screw bosses 100b. The outlet member 104 is fixed to the case member 100 by passing a plurality of screws 110 through the corresponding screw receiving portions 104b and threading them into the corresponding screw bosses 100b. A seal member 20d (see FIG. 2) is disposed at the connection point between the case member 100 and the outlet member 104, and the connection point between the case member 100 and the outlet member 104 is sealed by the seal member 20d.

[0023] As shown in FIG. 2 , a passage member 10 and a plurality of swirl flow generating members 30 are housed inside a case member 100 of the mixer 2. The passage member 10 and the plurality of swirl flow generating members 30 are arranged side by side along the central axis A. In the following description, within the case member 100, the space formed between one end of the passage member 10 (the right end in FIG. 2 ) and the inlet member 102 is referred to as a first inlet section 10a, the space formed between the other end of the passage member 10 (the left end in FIG. 2 ) and the plurality of swirl flow generating members 30 is referred to as an outlet section 10b, and the space formed between the side surface 16 of the passage member 10 and the case member 100 is referred to as a second inlet section 16a. The first inlet section 10a is connected to an inlet 102a of the inlet member 102. The second inlet section 16a is connected to an inlet 106a of a supply section 106 (see FIG. 1 ). The outflow portion 10b is connected to the outlet 104a of the outlet member 104 via a plurality of swirl flow generating members 30. Furthermore, with respect to the passage member 10, one end side (the right side in FIG. 2) is also referred to as the upstream side, and the other end side (the left side in FIG. 2) is also referred to as the downstream side. The plurality of swirl flow generating members 30 are arranged side by side on the downstream side of the passage member 10. Each of the plurality of swirl flow generating members 30 has a shape that generates a swirl flow in the fluid passing through it.

[0024] (Configuration of Passage Member 10) As shown in FIG. 3, the passage member 10 has a generally solid-of-revolution shape centered on the central axis A. An upstream seal holder 15a is formed near the upstream end of the side surface 16 of the passage member 10. The upstream seal holder 15a includes an upstream groove 17a, an upstream fitting portion 18a that protrudes radially outward on the upstream side of the upstream groove 17a, and an upstream locking portion 19a that protrudes radially outward on the downstream side of the upstream groove 17a. As shown in FIG. 2, a seal member 20a is held in the upstream seal holder 15a. The seal member 20a seals the gap between the upstream seal holder 15a and the case member 100, thereby suppressing fluid movement between the first inlet portion 10a and the second inlet portion 16a outside the passage member 10. As shown in FIG. 3, a downstream seal holder 15b is formed near the downstream end of the side surface 16 of the passage member 10. The downstream seal retaining portion 15b includes a downstream groove portion 17b, a downstream fitting portion 18b that protrudes radially outward downstream of the downstream groove portion 17b, and a downstream locking portion 19b that protrudes radially outward upstream of the downstream groove portion 17b. As shown in Fig. 2, a seal member 20b is retained in the downstream seal retaining portion 15b. The seal member 20b seals the gap between the downstream seal retaining portion 15b and the case member 100, thereby suppressing fluid movement between the second inlet portion 16a and the outlet portion 10b outside the passage member 10.

[0025] A plurality of first fluid flow paths 12 and a plurality of second fluid flow paths 14 are formed inside the passage member 10. Each of the plurality of first fluid flow paths 12 communicates between the first inlet portion 10a and the outlet portion 10b. Each of the plurality of second fluid flow paths 14 communicates between the second inlet portion 16a and a respective one of the plurality of first fluid flow paths 12. Each of the plurality of first fluid flow paths 12 includes a reduced-diameter flow path 22 whose flow path diameter decreases from the upstream side to the downstream side, an expanded-diameter flow path 24 that is provided downstream of the reduced-diameter flow path 22 and whose flow path diameter increases from the upstream side to the downstream side, and a constant-diameter flow path 23 that communicates between the reduced-diameter flow path 22 and the expanded-diameter flow path 24 and has a constant flow path diameter. The side surface 16 of the passage member 10 includes an expanded-diameter portion 16b whose diameter increases from the upstream side to the downstream side. The same-diameter flow paths 23 and the expanded-diameter flow paths 24 of each of the plurality of first fluid flow paths 12 are disposed within the expanded-diameter section 16b. The upstream end of each of the plurality of second fluid flow paths 14 is connected to the second inlet section 16a, and the downstream end is connected to the same-diameter flow path 23 of the first fluid flow path 12. The plurality of second fluid flow paths 14 are formed linearly from their upstream ends to their downstream ends, and are disposed along a plane perpendicular to the flow direction of the plurality of first fluid flow paths 12 (i.e., the direction along the central axis A).

[0026] As shown in FIG. 3 , in this embodiment, the multiple first fluid flow paths 12 include one first fluid flow path 12a disposed on the central axis A and seven first fluid flow paths 12b disposed in a circumferential row radially outside the first fluid flow path 12a. In this embodiment, two slits 13 are formed in the expanded diameter flow path 24 of one first fluid flow path 12a disposed on the central axis A. The slits 13 have a U-shaped groove shape extending radially outward from the expanded diameter flow path 24. As shown in FIG. 2 , the slits 13 extend from near the upstream end to the downstream end of the expanded diameter flow path 24. The formation of the slits 13 in the expanded diameter flow path 24 of the first fluid flow path 12a can prevent a water film from forming in the expanded diameter flow path 24 of the first fluid flow path 12a.

[0027] In the mixer 2, when a first fluid flows into the first inlet section 10a through the inlet 102a, the first fluid flows into each of the reduced-diameter flow channels 22 of the multiple first-fluid flow channels 12. The flow velocity of the first fluid that flows into the reduced-diameter flow channels 22 increases as it passes through the reduced-diameter flow channels 22, resulting in a reduced pressure and the first fluid flowing into the same-diameter flow channels 23. This creates a negative pressure inside the same-diameter flow channels 23, and the second fluid is sucked into the second inlet section 16a through the inlet 106a and the supply port 106b (see FIG. 1), causing the second fluid to flow into each of the multiple second-fluid flow channels 14. As the second fluid passes through the second-fluid flow channels 14 and flows into the same-diameter flow channels 23, the first and second fluids mix within the same-diameter flow channels 23. The mixed fluid of the first and second fluids flows from the same-diameter flow channels 23 into the expanded-diameter flow channels 24, where its flow velocity decreases as it passes through the expanded-diameter flow channels 24, resulting in an increased pressure. The mixed fluid then flows into the multiple swirl flow generating members 30 through the outlet 10b. As the mixed fluid passes through the multiple swirl flow generating members 30, a swirling flow is generated, stirring the mixed fluid and resulting in a more uniform mixture. The mixed fluid is then discharged from the outlet 104a. In this embodiment, when the first fluid is water and the second fluid is air, the water is decompressed as it passes through the diameter-reducing flow path 22, creating a negative pressure inside the same-diameter flow path 23. This causes the air dissolved in the water to turn into bubbles, generating microbubbles in the water. Furthermore, as the water is pressurized as it passes through the diameter-increasing flow path 24, the air bubbles mixed in the water break up, generating more microbubbles in the water. Furthermore, as the water passes through the multiple swirl flow generating members 30, the microbubbles can be further broken down into smaller bubbles.

[0028] As shown in FIG. 4 , in this embodiment, some of the second fluid flow paths 14 a among the plurality of second fluid flow paths 14 are arranged such that their upstream ends are located in a first direction (e.g., a direction from right to left in FIG. 4 ) as viewed from the downstream end, and the remaining second fluid flow paths 14 b among the plurality of second fluid flow paths 14 are arranged such that their upstream ends are located in a second direction (e.g., a direction from left to right in FIG. 4 ) that is different from the first direction as viewed from the downstream end. In particular, in this embodiment, the second direction is the opposite direction to the first direction (a direction that forms an angle of 180° with respect to the first direction). The first fluid flow paths 12 (in the example of FIG. 4 , the first fluid flow path 12 a on the central axis A and the four first fluid flow paths 12 b to the left of the central axis A) that communicate with the second fluid flow paths 14 a whose upstream ends are located in the first direction as viewed from the downstream end are arranged such that the distance to the side surface 16 in the first direction is less than the distance to the side surface 16 in the second direction. The first fluid flow paths 12 (in the example of FIG. 4, the three first fluid flow paths 12b on the right side of the central axis A) which communicate with the second fluid flow paths 14b whose upstream ends are located in the second direction when viewed from the downstream end, are arranged at positions where the distance to the side surface 16 in the second direction is equal to or less than the distance to the side surface 16 in the first direction. In this embodiment, the supply port 106b of the supply unit 106 is arranged so as to face the side surface 16 at the center position between the end of the side surface 16 of the passage member 10 in the first direction and the end of the side surface 16 of the passage member 10 in the second direction in a direction perpendicular to the first direction and the second direction (for example, a direction from bottom to top in FIG. 4).

[0029] (Method of Manufacturing Passage Member 10) The passage member 10 can be manufactured by injection molding using, for example, a resin (such as polypropylene or polyphenylene sulfide). The mold used in manufacturing the passage member 10 includes a first mold corresponding to the shape of the upstream end face of the passage member 10 and the shapes of the reduced-diameter flow paths 22 and the equal-diameter flow paths 23 of each of the plurality of first fluid flow paths 12, a second mold corresponding to the shape of the downstream end face of the passage member 10 and the shapes of the expanded-diameter flow paths 24 of each of the plurality of first fluid flow paths 12, a third mold corresponding to the shape of the side face 16 of the passage member 10 in the first direction and the shape of some of the second fluid flow paths 14a of the plurality of second fluid flow paths 14, and a fourth mold corresponding to the shape of the side face 16 of the passage member 10 in the second direction and the shape of the remaining second fluid flow paths 14b of the plurality of second fluid flow paths 14. After molding the passage member 10, the passage member 10 can be removed from the molds by moving the first mold in the upstream direction, moving the second mold in the downstream direction, moving the third mold in the first direction, and moving the fourth mold in the second direction.

[0030] In the mixing device 2, the case member 100 can also be manufactured by injection molding using, for example, a resin (such as polypropylene or polyphenylene sulfide). In this case, sink marks are likely to occur during molding at the inner surface of the case member 100 at a location corresponding to the supply unit 106. In this embodiment, the seal members 20a and 20c are disposed upstream of the supply unit 106, and the seal members 20b and 20d are disposed downstream of the supply unit 106. In this manner, by disposing the seal members 20a, 20b, 20c, and 20d at locations that do not overlap with the supply unit 106, it is possible to prevent sink marks occurring at the inner surface of the case member 100 at a location corresponding to the supply unit 106 from affecting the sealing properties of the seal members 20a, 20b, 20c, and 20d. It should be noted that there is a risk of sink marks occurring during molding at locations on the inner surface of the case member 100 that correspond to the screw boss portions 100a and 100b. However, the sink marks that occur at these locations are smaller than the sink marks that occur at the location that corresponds to the supply portion 106, and therefore have little effect on the sealing properties of the sealing members 20a, 20b, 20c, and 20d.

[0031] (Modification) The mixer 2 may include only the passage member 10 , and may not include the swirl flow generating member 30 .

[0032] The supply port 106b may be disposed so as to face the side surface 16 of the passage member 10 in a direction other than the direction perpendicular to the first direction and the second direction.

[0033] The first fluid may be a liquid other than water or may be a gas, and the second fluid may be a gas other than air or may be a liquid. For example, the first fluid may be water and the second fluid may be a liquid detergent.

[0034] The plurality of first fluid flow paths 12 do not necessarily have to include one first fluid flow path 12a arranged on the central axis A. The plurality of first fluid flow paths 12 do not necessarily have to include a slit 13. The arrangement of the plurality of first fluid flow paths 12 in a plane perpendicular to the central axis A is not limited to the above embodiment, and any arrangement is possible. The number of the plurality of first fluid flow paths 12 may be any number as long as it is three or more.

[0035] Each of the plurality of first fluid flow paths 12 does not have to include the same-diameter flow path 23, and the reduced-diameter flow path 22 and the increased-diameter flow path 24 may be directly connected to each other.

[0036] As shown in FIG. 5, the second fluid flow paths 14 may be arranged to intersect with a plane perpendicular to the flow direction of the first fluid flow paths 12 (i.e., the direction along the central axis A).

[0037] The downstream ends of the multiple second fluid flow paths 14 do not have to be connected to the same-diameter flow path 23, but may be connected, for example, to the vicinity of the downstream end of the reduced-diameter flow path 22 or the vicinity of the upstream end of the expanded-diameter flow path 24.

[0038] The connection positions between the plurality of second fluid flow paths 14 and the plurality of first fluid flow paths 12 may be different in the flow direction of the plurality of first fluid flow paths 12 (i.e., the direction along the central axis A).

[0039] As shown in FIG. 6, for the plurality of second fluid flow paths 14, the second direction does not have to be opposite to the first direction (i.e., at an angle of 180° with respect to the first direction).

[0040] 7, all of the second fluid flow paths 14 may be arranged such that their upstream ends are positioned in the first direction when viewed from their downstream ends. In this case, the supply port 106b of the supply unit 106 may be arranged to face the side surface 16 of the passage member 10 in the first direction.

[0041] The inner surface 18 of the case member 100 does not have to have a substantially cylindrical shape. For example, the inner surface 18 of the case member 100 may have a rectangular tubular shape. In this case, the side surface 16 of the passage member 10 may have the same rectangular tubular shape as the inner surface 18.

[0042] The side surface 16 of the passage member 10 may not have the expanded diameter portion 16b. For example, the side surface 16 of the passage member 10 may have a cylindrical shape with the central axis A as the center.

[0043] The passage member 10 and the case member 100 may be made of metal (for example, aluminum or stainless steel).

[0044] (Correspondence) In this embodiment, the mixing device 2 mixes a first fluid (e.g., water) with a second fluid (e.g., air) to produce a mixed fluid. The mixing device 2 includes a first inlet 10a into which the first fluid flows, a second inlet 16a into which the second fluid flows, an outlet 10b from which the mixed fluid flows, and a passage member 10 arranged such that one end faces the first inlet 10a, the other end faces the outlet 10b, and a side surface 16 between the one end and the other end faces the second inlet 16a. The passage member 10 includes a plurality of first fluid flow paths 12, each of which connects the first inlet 10a and the outlet 10b, and a plurality of second fluid flow paths 14, each of which connects the second inlet 16a and each of the plurality of first fluid flow paths 12. The plurality of first fluid flow paths 12 includes at least three first fluid flow paths 12. Each of the plurality of first fluid flow paths 12 includes a reduced-diameter flow path 22 whose flow path diameter decreases from the first inlet portion 10 a toward the outlet portion 10 b, and an increased-diameter flow path 24 located downstream of the reduced-diameter flow path 22 and whose flow path diameter increases from the first inlet portion 10 a toward the outlet portion 10 b. Each of the plurality of second fluid flow paths 14 has a downstream end communicating with the first fluid flow path 12 downstream of the reduced-diameter flow path 22 and is formed linearly from its upstream end to its downstream end. Some of the plurality of second fluid flow paths 14 are arranged such that their upstream ends, as viewed from their downstream ends, are positioned in a first direction, and the remaining plurality of second fluid flow paths 14 are arranged such that their upstream ends, as viewed from their downstream ends, are positioned in the first direction (see FIG. 7 ) or a second direction different from the first direction (see FIG. 4 ).

[0045] According to the above configuration, for example, when the passage member 10 is manufactured by injection molding using resin, even if the passage member 10 has three or more first fluid flow paths 12, it is only necessary to prepare one or two molds corresponding to each of the plurality of second fluid flow paths 14 for demolding after molding. According to the above configuration, the processability of the passage member 10 can be further improved.

[0046] In one embodiment of the present technology, as shown in FIG. 2 , the plurality of second fluid flow paths 14 are arranged along a plane perpendicular to the flow direction of the plurality of first fluid flow paths 12 .

[0047] According to the above configuration, for example, when the passage member 10 is manufactured by injection molding using a resin, it is possible to perform demolding of a mold corresponding to the plurality of second fluid flow paths 14 without using a slide mechanism that slides the passage member 10 in the flow direction of the plurality of first fluid flow paths 12. This makes it possible to prevent the mold configuration from becoming complicated. According to the above configuration, it is possible to further improve the processability of the passage member 10.

[0048] In one embodiment of the present technology, as shown in FIG. 4 , the remaining second fluid flow paths 14 are arranged such that their upstream ends are positioned in a second direction when viewed from the downstream ends, and the second direction is opposite to the first direction.

[0049] According to the above configuration, for example, when manufacturing the passage member 10 by injection molding using resin, the removal direction (i.e., first direction) of the mold corresponding to a portion of the plurality of second fluid flow paths 14 (i.e., second fluid flow path 14a) can be opposite to the removal direction (i.e., second direction) of the mold corresponding to the remainder of the plurality of second fluid flow paths 14 (i.e., second fluid flow path 14b). This allows the mold corresponding to a portion of the plurality of second fluid flow paths 14 (i.e., second fluid flow path 14a) to be removed in the first direction and the mold corresponding to the remainder of the plurality of second fluid flow paths 14 (i.e., second fluid flow path 14b) to be removed in the second direction symmetrically while holding the passage member 10 in the same orientation, thereby enabling the construction of a mold with excellent demoldability. According to the above configuration, the processability of the passage member 10 can be further improved.

[0050] 4 , the first fluid flow paths 12a, 12b, which communicate with some of the plurality of second fluid flow paths 14 (i.e., the second fluid flow path 14a), are arranged at positions where the distance to the side surface 16 in the first direction is equal to or less than the distance to the side surface 16 in the second direction. The first fluid flow path 12b, which communicates with the rest of the plurality of second fluid flow paths 14 (i.e., the second fluid flow path 14b), is arranged at a position where the distance to the side surface 16 in the second direction is equal to or less than the distance to the side surface 16 in the first direction.

[0051] According to the above configuration, the length of each of the plurality of second fluid flow paths 14 can be shortened. This reduces the pressure loss when the second fluid passes through the plurality of second fluid flow paths 14, allowing a larger amount of second fluid to flow in. Furthermore, for example, when the passage member 10 is manufactured by injection molding using a resin, the length of the pin-shaped mold corresponding to the plurality of second fluid flow paths 14 can be shortened, and damage to the mold during the manufacturing of the passage member 10 can be suppressed.

[0052] In one embodiment of the present technology, the device further includes a case member 100 that houses the passage member 10. The case member 100 includes a supply port 106b that supplies the second fluid to the second inlet portion 16a. As shown in Fig. 4 , the supply port 106b is arranged to face the side surface 16 of the passage member 10 in a direction perpendicular to the first direction and the second direction, at a center position between an end of the side surface 16 of the passage member 10 in the first direction and an end of the side surface 16 of the passage member 10 in the second direction.

[0053] The above configuration reduces the deviation in the distance from the supply port 106b to the upstream ends of the second fluid flow paths 14. This allows the second fluid flowing in from the second inlet 16a to flow evenly into some of the second fluid flow paths 14 (i.e., second fluid flow path 14a) and the remaining second fluid flow paths 14 (i.e., second fluid flow path 14b).

[0054] In one embodiment of the present technology, the side surface 16 of the passage member 10 includes an expanded diameter portion 16b whose diameter expands from the first inlet portion 10a toward the outlet portion 10b. Each of the plurality of first fluid flow paths 12 communicates with a reduced diameter flow path 22 and an expanded diameter flow path 24, and further includes a same-diameter flow path 23 having a constant flow path diameter. The expanded diameter flow path 24 and the same-diameter flow path 23 of each of the plurality of first fluid flow paths 12 are disposed inside the expanded diameter portion 16b. A downstream end of each of the plurality of second fluid flow paths 14 communicates with the same-diameter flow path 23 of the first fluid flow path 12.

[0055] According to the above configuration, the same-diameter flow path 23 has the smallest diameter among the first fluid flow paths 12 and is therefore the flow path that is most depressurized. This further improves the suction effect of the second fluid into the second fluid flow path 14 that is connected to the same-diameter flow path 23. When the downstream end of the second fluid flow path 14 is connected to the same-diameter flow path 23, the second fluid flow path 14 is likely to be longer than when the downstream end of the second fluid flow path 14 is connected to the reduced-diameter flow path 22 or the expanded-diameter flow path 24. However, according to the above configuration, the expanded-diameter portion 16b is formed on the side surface 16 of the passage member 10, and the same-diameter flow path 23 and the expanded-diameter flow path 24 are disposed within the expanded-diameter portion 16b. This allows the length of the second fluid flow path 14 to be shorter than when the diameter of the side surface 16 of the passage member 10 is constant. Therefore, the length of the second fluid flow path 14 can be shortened while enhancing the suction effect of the second fluid. This reduces pressure loss in the second fluid flow path 14, allowing more second fluid to flow in. Furthermore, for example, when the passage member 10 is manufactured by injection molding using resin, the length of the pin-shaped mold corresponding to the plurality of second fluid flow paths 14 can be shortened, and damage to the mold forming the second fluid flow paths 14 during the manufacturing of the passage member 10 can be suppressed.

Claims

1. A mixing device for mixing a first fluid with a second fluid to produce a mixed fluid, comprising: a first inflow section into which the first fluid flows in; a second inflow section into which the second fluid flows; an outflow section from which the mixed fluid flows out; and a passage member arranged such that one end faces the first inflow section, the other end faces the outflow section, and a side surface between the one end and the other end faces the second inflow section, the passage member having a plurality of first fluid flow paths, each of which communicates between the first inflow section and the outflow section, and a plurality of second fluid flow paths, each of which communicates between the second inflow section and each of the plurality of first fluid flow paths, the plurality of first fluid flow paths comprising at least three first fluid flow paths, each of the plurality of first fluid flow paths comprising: a reduced diameter flow path whose flow path diameter reduces from the first inflow section side to the outflow section side; and an increased diameter flow path provided downstream of the reduced diameter flow path and whose flow path diameter increases from the first inflow section side to the outflow section side, a mixing device in which each of the plurality of second fluid flow paths has a downstream end connected to the first fluid flow path and is formed in a straight line from the upstream end to the downstream end, some of the plurality of second fluid flow paths are arranged such that their upstream ends are located in a first direction when viewed from the downstream end, and the remainder of the plurality of second fluid flow paths are arranged such that their upstream ends are located in the first direction or in a second direction different from the first direction when viewed from the downstream end.

2. The mixing device of claim 1, wherein said plurality of second fluid flow paths are arranged along a plane perpendicular to the flow direction of said plurality of first fluid flow paths.

3. The mixing device of claim 2, wherein the remainder of the plurality of second fluid flow paths are arranged such that their upstream ends are positioned in the second direction when viewed from their downstream ends, and the second direction is opposite to the first direction.

4. The mixing device of claim 3, wherein the first fluid flow paths with which the portion of the plurality of second fluid flow paths are connected are positioned at a position such that the distance to the side surface in the first direction is less than or equal to the distance to the side surface in the second direction, and the first fluid flow paths with which the remainder of the plurality of second fluid flow paths are connected are positioned at a position such that the distance to the side surface in the second direction is less than or equal to the distance to the side surface in the first direction.

5. A mixing device according to claim 3 or 4, further comprising a case member that houses the passage member, the case member having a supply port that supplies the second fluid to the second inlet portion, the supply port being arranged so as to face the side surface of the passage member in a direction perpendicular to the first direction and the second direction, at a central position between the end of the side surface of the passage member in the first direction and the end of the side surface of the passage member in the second direction.

6. A mixing device according to any one of claims 2 to 5, wherein the side surface of the passage member is provided with an enlarged diameter section that enlarges in diameter from the first inlet side toward the outlet side, each of the plurality of first fluid flow paths further comprises a same-diameter flow path that communicates with the reduced-diameter flow path and the enlarged-diameter flow path and has a constant flow path diameter, the same-diameter flow path and the enlarged-diameter flow path of each of the plurality of first fluid flow paths are disposed inside the enlarged diameter section, and each of the plurality of second fluid flow paths has a downstream end that communicates with the same-diameter flow path of the first fluid flow path.

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