injector

Abstract

The present application provides a kind of ejector that can maintain the positional relationship of inner nozzle and outer nozzle at desired positional relationship.The present application is a kind of ejector (1) with inner nozzle (25) and outer nozzle (26) with inner nozzle (25) arranged inside, outer injection hole (32) is arranged between inner nozzle (25) and outer nozzle (26), the ejector (1) uses the negative pressure generated by working fluid injected from the inner side or / and outer injection hole (32) of inner nozzle (25) to suck target fluid, makes target fluid and working fluid confluence and discharge, wherein the ejector (1) has nozzle guide (51), the nozzle guide (51) is arranged in the gap between inner nozzle (25) and outer nozzle (26), and the interval of outer injection hole (32) is limited.

Description

Technical Field

[0001] The present invention relates to an injector that generates negative pressure by causing the working fluid to flow, and uses the effect of the negative pressure to cause the target fluid to flow. Background Technology

[0002] Patent Document 1 discloses an injector that serves as a nozzle for injecting working fluid. The injector has an inner nozzle, namely a first nozzle, and an outer nozzle, namely a second nozzle, on which the first nozzle is disposed.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2002-56869 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] In the injector disclosed in Patent Document 1, the positional relationship between the first nozzle and the second nozzle is that they are coaxial. However, during and after the assembly of the first and second nozzles, the first nozzle may become eccentric relative to the second nozzle, making it impossible to maintain the desired positional relationship (i.e., coaxial relationship) between the first and second nozzles. As a result, it is impossible to stably inject the working fluid between the first and second nozzles, and the flow rate of the target fluid flowing by the action of the working fluid may be unstable.

[0008] Therefore, the present invention was made to solve the above-mentioned problems, with the aim of providing an injector capable of maintaining the positional relationship between the inner nozzle and the outer nozzle at a desired positional relationship.

[0009] Solution for solving the problem

[0010] To address the aforementioned problems, the present invention provides a jetting device comprising: an inner nozzle and an outer nozzle, wherein the inner nozzle is disposed on its inner side, and a gap is provided between the inner nozzle and the outer nozzle. The jetting device utilizes negative pressure generated by working fluid ejected from the inner side of the inner nozzle and / or the gap to draw in a target fluid, causing the target fluid to merge with the working fluid and be discharged. The jetting device is characterized in that it has a gap-limiting portion disposed within the gap, limiting the interval of the gap.

[0011] According to this technical solution, the gap between the inner nozzle and the outer nozzle is limited by the gap limiting part, thus maintaining the positional relationship between the inner nozzle and the outer nozzle at the desired positional relationship. Furthermore, this stabilizes the flow rate of the working fluid ejected from the gap between the inner nozzle and the outer nozzle, thereby stabilizing the flow rate of the target fluid flowing under the action of the working fluid, enabling the target fluid to flow at the desired flow rate.

[0012] In the above technical solution, it is preferred that an outer injection hole is provided on the inner side of the front end of the outer nozzle, and the interval limiting part is positioned upstream of the working fluid in the flow direction of the outer injection hole.

[0013] According to this technical solution, without reducing the flow rate of the working fluid ejected from the outer injection hole, the positional relationship between the inner and outer nozzles can be maintained at the desired positional relationship.

[0014] In the above technical solution, it is preferred that the upstream end of the working fluid in the flow direction of the interval limiting part is formed into a shape that converges towards the upstream side.

[0015] According to this technical solution, it is possible to suppress the situation where the gap limiting part becomes a resistance to the flow of the working fluid. Therefore, it is possible to suppress the situation where the flow rate of the working fluid injected from the gap between the inner nozzle and the outer nozzle is reduced due to the gap limiting part.

[0016] In the above technical solution, it is preferred that the downstream end of the working fluid in the flow direction of the interval limiting part is formed into a shape that converges towards the downstream side.

[0017] According to this technical solution, the flow of the working fluid is rectified by the interval limiting section. Therefore, the target fluid can be made to flow stably by utilizing the effect of the rectified working fluid, thus ensuring a stable flow rate of the target fluid.

[0018] In the above technical solution, preferably, the injector has a target fluid supply port for supplying the target fluid, and the cross-sectional area of ​​the gap, as viewed from the axial direction of the inner nozzle, is larger closer to the target fluid supply port.

[0019] According to this technical solution, the flow rate of the working fluid ejected from the gap between the inner and outer nozzles near the target fluid supply port can be increased. Therefore, it is possible to suppress the reduction in the flow rate of the working fluid ejected from the gap between the inner and outer nozzles due to the inflow of the target fluid from the target fluid supply port. Consequently, the flow rate of the target fluid flowing using the action of the working fluid can be maintained.

[0020] In the above technical solution, preferably, the interval limiting part is configured such that the axis connecting the upstream end and the downstream end of the interval limiting part in the flow direction of the working fluid is inclined relative to the flow direction of the working fluid.

[0021] According to this technical solution, the axis of the gap limiting part is inclined relative to the flow direction of the working fluid. Therefore, the working fluid can flow while rotating circumferentially around the inner and outer nozzles, and be ejected from the gap between the inner and outer nozzles. As a result, the target fluid can easily flow by utilizing the action of the working fluid ejected from the gap between the inner and outer nozzles, thereby increasing the suction volume of the target fluid.

[0022] In the above technical solution, preferably, the injector has: a target fluid supply port for supplying the target fluid; and a diffuser that uses the negative pressure generated by the working fluid to draw in the target fluid, so that the target fluid and the working fluid merge and are sent out to the discharge port, wherein the suction port of the diffuser is formed in an egg shape such that the opening area on the side of the target fluid supply port is increased.

[0023] According to this technical solution, the target fluid can be easily drawn from the portion of the diffuser's suction port near the target fluid supply port. Therefore, the amount of target fluid drawn into the diffuser can be increased, thereby increasing the flow rate of the target fluid.

[0024] The effects of the invention

[0025] According to the injector of the present invention, the positional relationship between the inner nozzle and the outer nozzle can be maintained at the desired positional relationship. Attached Figure Description

[0026] Figure 1 This is a cross-sectional view of the injector in this embodiment.

[0027] Figure 2 This is an enlarged view of the front periphery of the inner and outer nozzles.

[0028] Figure 3 This is the first embodiment. Figure 2 The AA cross-sectional view is shown. Furthermore, for ease of explanation, the cross-sectional view of the main shell is omitted.

[0029] Figure 4 This is a diagram showing the nozzle guide as viewed from the inside of the outer nozzle.

[0030] Figure 5 The diagram shows the inner circumferential surface of the outer nozzle of the second embodiment unfolded into a planar shape.

[0031] Figure 6 It is equivalent to the third embodiment. Figure 2 The diagram shows the AA cross-section. Furthermore, for ease of explanation, the cross-sectional view of the main shell is omitted.

[0032] Figure 7 It is equivalent to the fourth embodiment. Figure 2 The diagram shows the AA cross-section. Furthermore, for ease of explanation, the cross-sectional view of the main shell is omitted.

[0033] Figure 8 This is a diagram showing the shape of the suction port of the diffuser in the modified example.

[0034] Figure 9 This is an enlarged view of the front periphery of the inner and outer nozzles in the prior art.

[0035] Explanation of reference numerals in the attached figures

[0036] 1. Injector; 11. Main housing; 25. Inner nozzle; 26. Outer nozzle; 27. Diffuser; 28. Outlet; 31. Inner injection hole; 32. Outer injection hole; 33. Flow path; 41. (Inner nozzle) front end; 42. (Outer nozzle) front end; 51. Nozzle guide; 61. Upstream end; 62. Downstream end; 71. Suction port; Lg. (Nozzle guide) axis. Detailed Implementation

[0037] The injector 1, which is an embodiment of the present invention, will be described.

[0038] <Overall Overview of the Injector>

[0039] First, a general overview of the injector 1 will be given.

[0040] like Figure 1 As shown, the injector 1 has a main housing 11. The main housing 11 is formed in a tubular shape to allow the flow of a working fluid (e.g., hydrogen) and a destination fluid (e.g., hydrogen exhaust gas).

[0041] The main body housing 11 is provided with a first working fluid supply port 21, a second working fluid supply port 22, a target fluid supply port 23, a negative pressure generating chamber 24, an inner nozzle 25, an outer nozzle 26, a diffuser 27, and an outlet 28.

[0042] The first working fluid supply port 21 is a supply port for supplying working fluid, and is connected to the inner injection hole 31, which serves as the flow path inside the inner nozzle 25 (see reference). Figure 2 The second working fluid supply port 22 is a supply port for supplying working fluid, and is connected to the outer injection hole 32 (see reference) which serves as the flow path between the inner nozzle 25 and the outer nozzle 26. Figure 2 Connect.

[0043] The target fluid supply port 23 is a supply port for supplying the target fluid and is connected to the negative pressure generating chamber 24. The negative pressure generating chamber 24 is a space for generating negative pressure using the working fluid.

[0044] The inner nozzle 25 and the outer nozzle 26 are nozzles for spraying working fluid supplied from the first working fluid supply port 21 and the second working fluid supply port 22, respectively. The inner nozzle 25 and the outer nozzle 26 are each formed into a generally cylindrical shape and are made of stainless steel, resin, or the like. The inner nozzle 25 is disposed inside the outer nozzle 26. Furthermore, the inner nozzle 25 is fixed, for example, by pressing it into the outer nozzle 26. Additionally, the front end portion 41 of the inner nozzle 25 and the front end portion 42 of the outer nozzle 26 are disposed in the negative pressure generating chamber 24. Furthermore, the front end portion 41 and the front end portion 42 are respectively the downstream side (hereinafter referred to as the "downstream side") in the flow direction of the working fluid from the inner nozzle 25 and the outer nozzle 26. Figure 2 The left end of the part is the part with the inner diameter reduced to its smallest size.

[0045] For example, such as Figures 1-3 As shown, the inner nozzle 25 and the outer nozzle 26 are arranged in a coaxial positional relationship (i.e., the axis L2 of the inner nozzle 25 coincides with the axis L3 of the outer nozzle 26). Furthermore, as... Figure 3 As shown, the axis L2 of the inner nozzle 25 and the axis L3 of the outer nozzle 26 are aligned with the axis L1 of the diffuser 27.

[0046] like Figure 2 As shown, an inner injection hole 31 for the flow of working fluid is provided on the inner side of the front end portion 41 of the inner nozzle 25. In addition, on the inner side of the front end portion 42 of the outer nozzle 26 (Technical Solution 2), specifically, between the outer peripheral surface 41a of the front end portion 41 of the inner nozzle 25 and the inner peripheral surface 42a of the front end portion 42 of the outer nozzle 26, as a gap, an outer injection hole 32 with an annular cross-section for the flow of working fluid is provided.

[0047] In this embodiment, such as Figure 2 and Figure 3 As shown, the upstream side (hereinafter referred to as the "upstream side") is located in the direction of the flow of the working fluid compared to the outer injection hole 32. Figure 2 The nozzle guide 51 is provided at a position on the right side of the outer nozzle 26, that is, at a position adjacent to the front end portion 42 on the upstream side, and at a position where the inner diameter of the outer nozzle 26 is increased relative to the inner diameter of the front end portion 42; in other words, at a position where the inner diameter of the outer nozzle 26 is larger than the minimum. The details of the nozzle guide 51 will be discussed later. Furthermore, the nozzle guide 51 is an example of the "interval limiting part" of the present invention.

[0048] The diffuser 27 has the following flow path: it is connected to the negative pressure generating chamber 24, and uses the negative pressure generated by the working fluid to draw in the target fluid, causing the target fluid and the working fluid to merge and be sent out to the outlet 28. The outlet 28 is the part that discharges the working fluid and the target fluid that have been flowing in the diffuser 27 to the outside.

[0049] The ejector 1 configured in this way uses working fluid supplied from the first working fluid supply port 21 and the second working fluid supply port 22 and ejected from the inner nozzle 25 and the outer nozzle 26 to generate a negative pressure in the negative pressure generating chamber 24. This negative pressure is used to draw the target fluid from the target fluid supply port 23 into the negative pressure generating chamber 24. Furthermore, the ejector 1 causes the target fluid and the working fluid to flow together towards the diffuser 27 and be discharged from the outlet 28 toward the supply target (not shown).

[0050] More specifically, the working fluid supplied to the first working fluid supply port 21 flows through the inner nozzle 25 and is injected into the negative pressure generating chamber 24 through its inner injection hole 31, flows through the diffuser 27, and is discharged from the outlet 28. Conversely, the working fluid supplied to the second working fluid supply port 22 flows through the outer nozzle 26 and is injected into the negative pressure generating chamber 24 through its outer injection hole 32, flows through the diffuser 27, and is discharged from the outlet 28.

[0051] Furthermore, due to the flow of such working fluid, a negative pressure is generated in the negative pressure generating chamber 24. The target fluid supplied to the target fluid supply port 23 is drawn into the negative pressure generating chamber 24 by this negative pressure, flows together with the working fluid in the diffuser 27 and mixes with the working fluid, and is discharged from the outlet 28.

[0052] <Instructions for Nozzle Guide>

[0053] Next, the nozzle guide 51 will be described.

[0054] In the past, such as Figure 9 As shown, no gap is provided between the inner nozzle 25 and the outer nozzle 26. Therefore, during and after assembly of the inner nozzle 25 and the outer nozzle 26, the inner nozzle 25 may be tilted or eccentric relative to the outer nozzle 26. Furthermore, if the inner nozzle 25 is eccentric in this way, the size of the outer injection hole 32 becomes uneven in the circumferential direction of the inner nozzle 25 and the outer nozzle 26. This results in a reduced flow rate of the working fluid ejected from the outer injection hole 32, or fluctuations in the flow rate of the working fluid ejected from the outer injection hole 32 in the circumferential direction of the inner nozzle 25 and the outer nozzle 26. Moreover, if the working fluid cannot be stably ejected from the outer injection hole 32, the flow rate of the target fluid flowing by the action of the working fluid may be unstable, preventing the desired flow rate of the target fluid from being achieved.

[0055] (First Embodiment)

[0056] Therefore, the first pair of embodiments will be described first.

[0057] In this embodiment, as Figure 2 and Figure 3 As shown, a nozzle guide 51 is provided in the gap between the inner nozzle 25 and the outer nozzle 26, and at a position upstream of the outer injection hole 32. The spacing of the outer injection holes 32 is limited by the nozzle guide 51 contacting the outer peripheral surface 25a of the inner nozzle 25. Furthermore, the spacing of the outer injection holes 32 refers to the radial spacing between the inner nozzle 25 and the outer nozzle 26 at the outer injection hole 32.

[0058] Specifically, such as Figure 2 and Figure 3 As shown, three nozzle guides 51 are provided on the inner circumferential surface 26a of the outer nozzle 26, located upstream of the front end 42, in a manner that they are equally spaced apart in the circumferential direction of the outer nozzle 26. However, the number of nozzle guides 51 is not limited to three; two or more are acceptable. Alternatively, the nozzle guides 51 may also be provided on the outer circumferential surface 25a of the inner nozzle 25, located upstream of the front end 41. Furthermore, the nozzle guides 51 may be components independent of the inner nozzle 25 and the outer nozzle 26.

[0059] In this way, by using the nozzle guide 51 to limit the spacing of the outer spray holes 32, the position of the inner nozzle 25 is guided radially between the inner nozzle 25 and the outer nozzle 26. Therefore, the spacing of the outer spray holes 32 (i.e., the gap between the outer peripheral surface 41a of the front end 41 of the inner nozzle 25 and the inner peripheral surface 42a of the front end 42 of the outer nozzle 26) can be kept constant. Thus, the spacing of the outer spray holes 32 can be kept constant by the nozzle guide 51 during and after the assembly of the inner nozzle 25 and the outer nozzle 26, and the tilting and eccentricity of the inner nozzle 25 relative to the outer nozzle 26 can be suppressed.

[0060] That is, the radial positional relationship between the inner nozzle 25 and the outer nozzle 26 can be maintained at the desired positional relationship (i.e., coaxial positional relationship). Therefore, the size of the outer injection hole 32 can be kept equal in the circumferential direction of the inner nozzle 25 and the outer nozzle 26. Thus, the reduction in the flow rate of the working fluid ejected from the outer injection hole 32 can be suppressed, and the fluctuation of the flow rate of the working fluid ejected from the outer injection hole 32 in the circumferential direction of the inner nozzle 25 and the outer nozzle 26 can be suppressed. Furthermore, the working fluid can be ejected stably from the outer injection hole 32 in this way, and thus the flow rate of the target fluid flowing by the action of the working fluid is stabilized, and the target fluid can flow at the desired flow rate. Therefore, the flow rate of the mixture of working fluid and target fluid discharged from the outlet 28 can be set to the desired flow rate.

[0061] Furthermore, there is no need to extend the fixing portion between the inner nozzle 25 and the outer nozzle 26, or increase the diameter of the inner nozzle 25 and the outer nozzle 26, in order to suppress the tilting and eccentricity of the inner nozzle 25 relative to the outer nozzle 26. Therefore, it is possible to prevent the overall size of the injector 1 from increasing.

[0062] In addition, such as Figure 4 As shown, the nozzle guide 51 is rhomboid when viewed from the inside of the outer nozzle 26. Furthermore, the inner circumferential surface 26a of the nozzle guide 51, located upstream of the outer nozzle 26 (front end 42), is arranged such that the diagonal of the major axis of the rhombus is parallel to the flow direction of the working fluid (i.e., the direction of the axis L3 of the outer nozzle 26). Thus, the upstream side of the nozzle guide 51 (i.e., the...)... Figure 4 The right end 61 of the nozzle guide 51 is formed in a shape that converges towards the upstream side. Additionally, the downstream side (in the flow direction of the working fluid) of the nozzle guide 51... Figure 4 The left end 62 is formed into a shape that converges toward the downstream side.

[0063] As described above, according to this embodiment, the injector 1 has a nozzle guide 51 that limits the spacing of the outer injection holes 32.

[0064] In this way, the spacing of the outer injection holes 32 (i.e., the spacing between the outer peripheral surface 41a of the front end 41 of the inner nozzle 25 and the inner peripheral surface 42a of the front end 42 of the outer nozzle 26) is limited by the nozzle guide 51. Therefore, the radial positional relationship between the inner nozzle 25 and the outer nozzle 26 can be maintained at the desired positional relationship (i.e., coaxial positional relationship). Furthermore, as a result, the working fluid can be stably injected from the outer injection holes 32, thus stabilizing the flow rate of the target fluid flowing by the action of the working fluid, and enabling the target fluid to flow at the desired flow rate.

[0065] In addition, the nozzle guide 51 is positioned upstream of the outer spray hole 32.

[0066] In this way, since the nozzle guide 51 is not provided at the position of the outer injection hole 32, which is located at the front end 42 of the smallest diameter portion of the outer nozzle 26, the cross-sectional area of ​​the flow path of the outer injection hole 32 is not reduced. Furthermore, compared to the case where the nozzle guide 51 is provided at the position of the outer injection hole 32, the cross-sectional area of ​​the flow path between the inner nozzle 25 and the outer nozzle 26 can be increased. Moreover, even assuming that the nozzle guide 51 becomes a resistance to the flow of the working fluid and causes turbulence, the working fluid can be stabilized (rectified) at the outer injection hole 32, which is located downstream of the nozzle guide 51. Therefore, without reducing the flow rate of the working fluid ejected from the outer injection hole 32, the positional relationship between the inner nozzle 25 and the outer nozzle 26 can be maintained at the desired positional relationship.

[0067] In addition, the upstream end 61 of the nozzle guide 51 is formed in a shape that converges towards the upstream side.

[0068] Therefore, it is possible to suppress the nozzle guide 51 from becoming a resistance to the flow of the working fluid. Thus, it is possible to suppress the reduction of the flow rate of the working fluid ejected from the outer injection hole 32 due to the nozzle guide 51.

[0069] In addition, the downstream end 62 of the nozzle guide 51 is formed in a shape that converges towards the downstream side.

[0070] Thus, the flow of the working fluid is rectified by the nozzle guide 51. Therefore, the target fluid can be made to flow stably by utilizing the effect of the rectified working fluid, and thus the flow rate of the target fluid is stable.

[0071] Furthermore, as a variation, either the upstream end 61 or the downstream end 62 of the nozzle guide 51 may be formed into a shape that converges towards the upstream or downstream side.

[0072] (Second Embodiment)

[0073] Next, the second embodiment will be described, but the points that differ from the first embodiment will be described, while the points that are common to the first embodiment will be omitted.

[0074] In this embodiment, as Figure 5 As shown, the nozzle guide 51 is positioned with its axis Lg relative to the flow direction of the working fluid (i.e., the direction of the axis L3 of the outer nozzle 26). Figure 5 The configuration is tilted in the left and right directions. For example, Figure 5As shown, axis Lg is the line connecting the upstream end 61 and the downstream end 62 of the nozzle guide 51.

[0075] In this embodiment, the axis Lg of the nozzle guide 51 is inclined relative to the flow direction of the working fluid, thus enabling the working fluid to flow in the circumferential direction of the inner nozzle 25 and the outer nozzle 26. Figure 5 The fluid flows in a cyclical pattern (up and down) while being ejected from the outer injection port 32. Therefore, the target fluid easily flows using the action of the working fluid ejected from the outer injection port 32, thus increasing the amount of target fluid drawn into the diffuser 27. Consequently, the mixture of the target fluid and the working fluid can be efficiently discharged from the outlet 28.

[0076] (Third Embodiment)

[0077] Next, the third embodiment will be described, but the points that differ from the first and second embodiments will be described, while the points that are common to the first and second embodiments will be omitted.

[0078] In this embodiment, as Figure 6 As shown, the closer to the target fluid supply port 23 (i.e., ... Figure 6 The nozzle guide 51 on the lower side) has a greater height Hg. Here, the height Hg refers to the radial width of the inner nozzle 25 and the outer nozzle 26 of the nozzle guide 51.

[0079] In this way, the closer the nozzle guide 51 is to the target fluid supply port 23, the greater the height Hg of the nozzle guide 51 becomes, such as... Figure 6 As shown, the inner nozzle 25 is positioned relative to the outer nozzle 26 towards the side opposite to the target fluid supply port 23 (i.e., Figure 6 The inner nozzle 25 is eccentric relative to the outer nozzle 26. Furthermore, by eccentricating the inner nozzle 25 relative to the outer nozzle 26, the cross-sectional area of ​​the outer injection hole 32, as observed from the axis L2 of the inner nozzle 25 (or the axis L3 of the outer nozzle 26), is closer to the target fluid supply port 23 (i.e., the upper side). Figure 6 The larger the lower side (of the body).

[0080] Specifically, the height Hg of the three nozzle guides 51 is set as (height Hg of the first nozzle guide 51-1) < (height Hg of the second nozzle guide 51-2 and height Hg of the third nozzle guide 51-3). Therefore, for the flow path 33 divided into three holes by the nozzle guides 51, the cross-sectional area of ​​the second flow path 33-2, which is closer to the target fluid supply port 23, is larger than the cross-sectional areas of the first flow path 33-1 and the third flow path 33-3. Furthermore, the flow path 33 is formed between the outer peripheral surface 25a of the inner nozzle 25 and the inner peripheral surface 26a of the outer nozzle 26, and is connected to the outer injection hole 32.

[0081] In this way, such as Figure 6 As shown, the axis L2 of the inner nozzle 25 is positioned relative to the axis L of the outer nozzle 26, away from the target fluid supply port 23. Figure 6 The inner nozzle 25 is offset from the outer nozzle 26 by offsetting the upper side of the outer nozzle 32, thus forcibly eccentricating the inner nozzle 25 relative to the outer nozzle 26. This increases the flow rate of the working fluid ejected from the outer nozzle 32 near the target fluid supply port 23. Therefore, it can suppress the reduction in the flow rate of the working fluid ejected from the outer nozzle 32 due to the inflow of target fluid from the target fluid supply port 23. Consequently, it is possible to maintain the flow rate of the target fluid flowing under the action of the working fluid.

[0082] (Example 4)

[0083] Next, the fourth embodiment will be described, but the points that differ from the first to third embodiments will be described, while the points that are common to the first to third embodiments will be omitted.

[0084] In this embodiment, as Figure 7 As shown, in the circumferential direction of the inner nozzle 25 and the outer nozzle 26, the spacing In between adjacent nozzle guides 51 is larger as they approach the target fluid supply port 23. Consequently, the cross-sectional area of ​​the outer injection hole 32, as observed from the axis L2 of the inner nozzle 25 (or the axis L3 of the outer nozzle 26), is larger as it approaches the target fluid supply port 23.

[0085] Specifically, for the three nozzle guides 51, the interval In between the second nozzle guide 51-2 and the third nozzle guide 51-3, which are closer to the target fluid supply port 23, is larger than the interval In between the first nozzle guide 51-1 and the second nozzle guide 51-2, and the interval In between the first nozzle guide 51-1 and the third nozzle guide 51-3. Furthermore, for the three flow paths 33 (connected to the outer injection holes 32) divided by the three nozzle guides 51, the cross-sectional area of ​​the second flow path 33-2, which is closer to the target fluid supply port 23, is larger than the cross-sectional area of ​​the first flow path 33-1 and the third flow path 33-3.

[0086] Therefore, similar to the third embodiment, it is possible to suppress the reduction in the flow rate of the working fluid ejected from the outer injection hole 32 due to the inflow of the target fluid. Thus, it is possible to maintain the flow rate of the target fluid that flows using the action of the working fluid.

[0087] (Modified Example)

[0088] As a variation, in embodiments 1 to 4, such as Figure 8 As shown, the suction port 71 of the diffuser 27 can also be formed in an egg shape by increasing the opening area on the side of the target fluid supply port 23.

[0089] Therefore, it is easy to draw the target fluid from the portion of the suction port 71 of the diffuser 27 on the side near the target fluid supply port 23. As a result, the amount of target fluid drawn into the diffuser 27 can be increased, and thus the flow rate of the target fluid can be increased.

[0090] Furthermore, the above-described embodiments are merely illustrative and do not limit the present invention in any way. Of course, various modifications and variations can be made without departing from the spirit of the invention.

[0091] For example, the nozzle guide 51 can also be a quadrangular prism with a rhomboid upper and lower surface, a cuboid, a cube, a cylinder, or other prisms.

[0092] In addition, the nozzle described above is a double-layered tube consisting of an inner nozzle 25 and an outer nozzle 26, but it can also be a nozzle with three or more layers.

Claims

1. An injector having: Inner nozzle; and An outer nozzle, with an inner nozzle disposed on its inner side. A gap is provided between the inner nozzle and the outer nozzle. The ejector utilizes the negative pressure generated by the working fluid ejected from the inside of the inner nozzle and / or the gap to draw in the target fluid, causing the target fluid to merge with the working fluid and then discharge it. The ejector is characterized in that... The injector has: An interval limiting portion is disposed in the gap to limit the interval of the gap; and The target fluid supply port is used to supply the target fluid. The inner circumferential surface of the outer nozzle has a portion with a constant inner diameter and an inclined portion with a gradually increasing inner diameter, which are sequentially provided from the front end of the outer nozzle towards the upstream side of the flow direction of the working fluid. The interval limiting part is located upstream of the target fluid supply port in the flow direction of the working fluid, and is located at the position of the inclined portion in the inner circumferential surface of the outer nozzle.

2. The injector according to claim 1, characterized in that, An outer spray hole is provided on the inner side of the front end of the outer nozzle. The interval limiting part is positioned upstream of the working fluid in the flow direction of the outer injection hole.

3. The injector according to claim 1 or 2, characterized in that, The upstream end of the interval limiting section in the direction of flow of the working fluid is formed in a shape that converges towards the upstream side.

4. The injector according to claim 1 or 2, characterized in that, The downstream end of the interval limiting section in the direction of flow of the working fluid is formed in a shape that converges toward the downstream side.

5. The injector according to claim 1 or 2, characterized in that, The cross-sectional area of ​​the gap, as observed from the axial direction of the inner nozzle, is larger the closer it is to the target fluid supply port.

6. The injector according to claim 1 or 2, characterized in that, The interval limiting part is configured such that the axis connecting the upstream end and the downstream end of the interval limiting part in the flow direction of the working fluid is inclined relative to the flow direction of the working fluid.

7. The injector according to claim 1 or 2, characterized in that, The injector has a diffuser that uses the negative pressure generated by the working fluid to draw in the target fluid, causing the target fluid to merge with the working fluid and be discharged towards the outlet. The diffuser's suction port is formed in an egg shape by increasing the opening area on the side of the target fluid supply port.

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