Ejector

Abstract

To provide an ejector capable of maintaining a physical relationship between an inside nozzle and an outside nozzle, as desired.SOLUTION: An ejector 1 has an inside nozzle 25, an outside nozzle 26 inside which the inside nozzle 25 is provided, and an outside injection hole 32 provided between the inside nozzle 25 and the outside nozzle 26, sucks target fluid using a negative pressure generated by working fluid injected from the inside of the inside nozzle 25 and / or the outside injection hole 32, and releases the target fluid while joining it with the working fluid. The ejector includes a nozzle guide 51 provided in a gap between the inside nozzle 25 and the outside nozzle 26 and regulating a distance from the outside injection hole 32.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to an ejector that generates a negative pressure by flowing a working fluid and causes a target fluid to flow by the action of the negative pressure.

Background Art

[0002] Patent Document 1 discloses an ejector having a first nozzle that is an inner nozzle and a second nozzle that is an outer nozzle and houses the first nozzle therein as nozzles for injecting a working fluid.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the ejector disclosed in Patent Document 1, the positional relationship between the first nozzle and the second nozzle is such that the first nozzle and the second nozzle are coaxial. However, during or after the assembly of the first nozzle and the second nozzle, the first nozzle may be eccentric with respect to the second nozzle, and there is a possibility that the positional relationship between the first nozzle and the second nozzle cannot be maintained in a desired positional relationship (that is, a coaxial positional relationship). Then, the working fluid cannot be stably ejected from between the first nozzle and the second nozzle, and there is a possibility that the flow rate of the target fluid flowing by the action of the working fluid is not stable.

[0005] Therefore, the present disclosure has been made to solve the above-described problems, and an object thereof is to provide an ejector that can maintain the positional relationship between an inner nozzle and an outer nozzle in a desired positional relationship.

Means for Solving the Problems

[0006] One embodiment of the present disclosure made to solve the above problems is an ejector having an inner nozzle and an outer nozzle having the inner nozzle inside, with a gap provided between the inner nozzle and the outer nozzle, which draws in a target fluid by negative pressure generated by a working fluid sprayed from inside the inner nozzle and / or from the gap, and discharges the target fluid after merging it with the working fluid, wherein the ejector has a gap restricting part provided in the gap to restrict the gap, and a target fluid supply port to which the target fluid is supplied, The inner circumferential surface of the outer nozzle comprises, in order from the tip side of the outer nozzle toward the upstream side in the flow direction of the working fluid, a portion with a constant inner diameter and a sloping portion with a gradually increasing inner diameter. The aforementioned spacing regulating section is provided at a position upstream of the target fluid supply port in the flow direction of the working fluid. Furthermore, it is provided at the position of the inclined portion on the inner circumferential surface of the outer nozzle. It is characterized by the following.

[0007] In this embodiment, the gap between the inner nozzle and the outer nozzle is restricted by the gap restricting section, so that the positional relationship between the inner nozzle and the outer nozzle can be maintained at the desired positional relationship. As a result, the flow rate of the working fluid injected from the gap between the inner nozzle and the outer nozzle is stabilized, so that the flow rate of the target fluid that flows due to the action of the working fluid is stabilized, and the target fluid can be flowed at the desired flow rate.

[0008] In the above embodiment, it is preferable that an outer injection hole is provided inside the tip of the outer nozzle, and the spacing regulating portion is positioned upstream of the outer injection hole in the flow direction of the working fluid.

[0009] According to this embodiment, the relative positions of the inner nozzle and the outer nozzle can be maintained in a desired positional relationship without reducing the flow rate of the working fluid injected from the outer injection port.

[0010] In the above embodiment, it is preferable that the upstream end of the spacing restricting portion in the direction of the working fluid flow is formed in a shape that converges toward the upstream side.

[0011] According to this embodiment, the gap restricting portion can be prevented from acting as resistance to the flow of the working fluid. Therefore, the reduction in the flow rate of the working fluid injected from the gap between the inner nozzle and the outer nozzle due to the gap restricting portion can be prevented.

[0012] In the above embodiment, it is preferable that the downstream end of the spacing restricting portion in the direction of the working fluid flow is formed in a shape that converges toward the downstream side.

[0013] In this embodiment, the flow of the working fluid is straightened by the spacing regulating section. As a result, the target fluid can be flowed stably due to the action of the straightened working fluid, and the flow rate of the target fluid is stabilized.

[0014] In the above embodiment, ,before Preferably, the cross-sectional area of ​​the gap, as viewed from the axial direction of the inner nozzle, is larger the closer it is to the target fluid supply port.

[0015] According to this embodiment, the flow rate of the working fluid injected from the portion of the gap between the inner nozzle and the outer nozzle closest to the target fluid supply port can be increased. Therefore, it is possible to suppress the reduction in the flow rate of the working fluid injected from the gap between the inner nozzle and the outer nozzle due to the inflow of the target fluid from the target fluid supply port. Thus, the flow rate of the target fluid flowed by the action of the working fluid can be maintained.

[0016] In the above embodiment, it is preferable that the spacing restricting portion is arranged such that the axis connecting the upstream end and the downstream end in the flow direction of the working fluid in the spacing restricting portion is inclined with respect to the flow direction of the working fluid.

[0017] According to this aspect, since the axis of the spacing regulating portion is inclined with respect to the flow direction of the working fluid, the working fluid can be caused to flow while swirling in the circumferential direction of the inner nozzle and the outer nozzle, and ejected from the gap between the inner nozzle and the outer nozzle. Therefore, the action of the working fluid ejected from the gap between the inner nozzle and the outer nozzle facilitates the flow of the target fluid, so that the suction amount of the target fluid can be increased.

[0018] In the above aspect ,before A diffuser that sucks the target fluid by the negative pressure generated by the working fluid, merges the target fluid with the working fluid, and sends it to the discharge port The has, and it is preferable that the suction port of the diffuser is formed in an elliptical shape such that the opening area on the side of the target fluid supply port is widened.

[0019] According to this aspect, it becomes easier to suck the target fluid from the portion on the side of the target fluid supply port at the suction port of the diffuser. Therefore, since the suction amount of the target fluid into the diffuser can be increased, the flow rate of the target fluid can be increased.

Effect of the Invention

[0020] According to the ejector of the present disclosure, the positional relationship between the inner nozzle and the outer nozzle can be maintained in a desired positional relationship.

Brief Description of the Drawings

[0021] [Figure 1] It is a cross-sectional view of the ejector of this embodiment. [Figure 2] It is an enlarged view around the tip portions of the inner nozzle and the outer nozzle. [Figure 3] It is a cross-sectional view taken along the line A-A of FIG. 2 in the first embodiment. For convenience of explanation, illustration of the cross-sectional portion of the main body casing is omitted. [Figure 4] It is a view of the nozzle guide as seen from the inside of the outer nozzle. [Figure 5] It is a view showing the inner peripheral surface of the outer nozzle of the second embodiment developed in a planar shape. [Figure 6]This figure corresponds to the AA cross-sectional view in Figure 2 of the third embodiment. For the sake of explanation, the cross-sectional view of the main casing has been omitted. [Figure 7] This figure corresponds to the AA cross-sectional view in Figure 2 of the fourth embodiment. For the sake of explanation, the cross-sectional view of the main casing has been omitted. [Figure 8] This figure shows the shape of the diffuser's intake port in a modified example. [Figure 9] This is a magnified view of the area around the tip of the inner and outer nozzles in the conventional technology. [Modes for carrying out the invention]

[0022] An embodiment of the present disclosure, Ejector 1, will be described below.

[0023] <Overall overview of the ejector> First, let's explain the overall overview of Ejector 1.

[0024] As shown in Figure 1, the ejector 1 has a main casing 11. This main casing 11 is tubular in shape to allow the working fluid (e.g., hydrogen gas) and the target fluid (e.g., hydrogen off-gas) to flow through it.

[0025] The main casing 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 a discharge port 28.

[0026] The first working fluid supply port 21 is a supply port to which working fluid is supplied and communicates with the inner injection hole 31 (see Figure 2), which is the flow path inside the inner nozzle 25. The second working fluid supply port 22 is a supply port to which working fluid is supplied and communicates with the outer injection hole 32 (see Figure 2), which is the flow path in the gap between the inner nozzle 25 and the outer nozzle 26.

[0027] The target fluid supply port 23 is a supply port to which the target fluid is supplied and is in communication with the negative pressure generation chamber 24. The negative pressure generation chamber 24 is a space for generating negative pressure using the working fluid.

[0028] The inner nozzle 25 and the outer nozzle 26 are nozzles for injecting 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 in a substantially cylindrical shape and are made of stainless steel or resin. The inner nozzle 25 is installed inside the outer nozzle 26. The inner nozzle 25 is fixed to the outer nozzle 26 by press-fitting, for example. The tip 41 of the inner nozzle 25 and the tip 42 of the outer nozzle 26 are located in the negative pressure generating chamber 24. The tip 41 and the tip 42 are the downstream ends (hereinafter simply referred to as the "downstream side"; left side in Figure 2) in the direction of working fluid flow in the inner nozzle 25 and the outer nozzle 26, respectively, and are the parts where the inner diameter is narrowed to the minimum.

[0029] Here, as an example, as shown in Figures 1 to 3, 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 and the axis L3 of the outer nozzle 26 coincide). Also, as shown in Figure 3, the axis L2 of the inner nozzle 25 and the axis L3 of the outer nozzle 26 coincide with the axis L1 of the diffuser 27.

[0030] As shown in Figure 2, the working fluid flows inside the tip 41 of the inner nozzle 25. A nozzle 31 is provided. Also, inside the tip 42 of the outer nozzle 26 teeth, More specifically, an outer injection hole 32 is provided between the outer circumferential surface 41a of the tip portion 41 of the inner nozzle 25 and the inner circumferential surface 42a of the tip portion 42 of the outer nozzle 26, with an annular cross-section through which the working fluid flows.

[0031] In this embodiment, as shown in Figures 2 and 3, a nozzle guide 51 is provided at a position upstream of the outer injection hole 32 in the direction of the working fluid flow (hereinafter simply referred to as "upstream side"; right side in Figure 2), that is, at a position adjacent to the tip portion 42 on the upstream side, where the inner diameter of the outer nozzle 26 is larger than that of the tip portion 42, or in other words, at a position where the inner diameter of the outer nozzle 26 is one step larger than the minimum. Details of this nozzle guide 51 will be described later. Note that the nozzle guide 51 is an example of the "spacing regulating portion" of this disclosure.

[0032] The diffuser 27 is a flow path that communicates with the negative pressure generating chamber 24 and uses the negative pressure generated by the working fluid to draw in the target fluid, combine the target fluid with the working fluid, and send it to the discharge port 28. The discharge port 28 is the part that discharges the working fluid and target fluid that have flowed through the diffuser 27 to the outside.

[0033] The ejector 1, configured in this way, generates negative pressure in the negative pressure generating chamber 24 by the 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. This negative pressure draws the target fluid into the negative pressure generating chamber 24 from the target fluid supply port 23. The ejector 1 then flows the target fluid together with the working fluid to the diffuser 27 and discharges it from the discharge port 28 toward the destination (not shown).

[0034] More specifically, the working fluid supplied to the first working fluid supply port 21 flows to the inner nozzle 25, is injected from its inner injection hole 31 into the negative pressure generating chamber 24, flows through the diffuser 27, and is discharged from the outlet 28. Similarly, the working fluid supplied to the second working fluid supply port 22 flows to the outer nozzle 26, is injected from its outer injection hole 32 into the negative pressure generating chamber 24, flows through the diffuser 27, and is discharged from the outlet 28.

[0035] Then, due to this flow of working fluid, negative pressure is generated in the negative pressure generating chamber 24, and 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 through the diffuser 27 together with the working fluid, mixes with the working fluid, and is discharged from the discharge port 28.

[0036] <Explanation of Nozzle Guide> Next, we will describe the nozzle guide 51.

[0037] Conventionally, as shown in Figure 9, nothing was provided in the gap between the inner nozzle 25 and the outer nozzle 26. Therefore, during or after assembly of the inner nozzle 25 and the outer nozzle 26, there was a risk that the inner nozzle 25 would tilt and become eccentric relative to the outer nozzle 26. When 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 can lead to a decrease in the flow rate of the working fluid injected from the outer injection hole 32, or to variations in the flow rate of the working fluid injected from the outer injection hole 32 in the circumferential direction of the inner nozzle 25 and the outer nozzle 26. If the working fluid cannot be stably injected from the outer injection hole 32 in this way, the flow rate of the target fluid that flows due to the action of the working fluid will not be stable, and there is a risk that the target fluid at the desired flow rate cannot be flowed.

[0038] (First embodiment) Therefore, let me first describe the first embodiment.

[0039] In this embodiment, as shown in Figures 2 and 3, a nozzle guide 51 is provided in the gap between the inner nozzle 25 and the outer nozzle 26, upstream of the outer injection hole 32. This nozzle guide 51 contacts the outer peripheral surface 25a of the inner nozzle 25, thereby regulating the spacing of the outer injection hole 32. The spacing of the outer injection hole 32 refers to the radial spacing between the inner nozzle 25 and the outer nozzle 26 within the outer injection hole 32.

[0040] Specifically, as shown in Figures 2 and 3, three nozzle guides 51 are provided on the inner circumferential surface 26a of the outer nozzle 26 at a position upstream of the tip portion 42, and are arranged at equal intervals in the circumferential direction of the outer nozzle 26. Note that the number of nozzle guides 51 is not limited to three; two or more are acceptable. The nozzle guides 51 may also be provided on the outer circumferential surface 25a of the inner nozzle 25 at a position upstream of the tip portion 41. Furthermore, the nozzle guides 51 may be separate components from the inner nozzle 25 and the outer nozzle 26.

[0041] In this way, by regulating the spacing of the outer injection holes 32 with the nozzle guide 51, the position of the inner nozzle 25 is guided in the radial direction of the inner nozzle 25 and outer nozzle 26. Therefore, the spacing of the outer injection holes 32 (i.e., the gap between the outer peripheral surface 41a of the tip portion 41 of the inner nozzle 25 and the inner peripheral surface 42a of the tip portion 42 of the outer nozzle 26) can be kept constant. Thus, during and after assembly of the inner nozzle 25 and outer nozzle 26, the nozzle guide 51 can keep the spacing of the outer injection holes 32 constant, preventing the inner nozzle 25 from tilting and becoming eccentric relative to the outer nozzle 26.

[0042] In other words, the radial positional relationship between the inner nozzle 25 and the outer nozzle 26 can be maintained at a desired positional relationship (i.e., a coaxial positional relationship in this case). Therefore, the size of the outer injection holes 32 can be kept uniform in the circumferential direction of the inner nozzle 25 and the outer nozzle 26. Consequently, a decrease in the flow rate of the working fluid injected from the outer injection holes 32 can be suppressed, and variations in the flow rate of the working fluid injected from the outer injection holes 32 in the circumferential direction of the inner nozzle 25 and the outer nozzle 26 can be suppressed. As a result, the working fluid can be stably injected from the outer injection holes 32, and the flow rate of the target fluid flowing due to the action of the working fluid can be stabilized, allowing the target fluid to flow at a desired flow rate. Therefore, the flow rate of the mixed fluid of the working fluid and the target fluid discharged from the outlet 28 can be set to a desired flow rate.

[0043] Furthermore, to prevent the inner nozzle 25 from tilting and becoming eccentric relative to the outer nozzle 26, it is not necessary to lengthen the fixing portion between the inner nozzle 25 and the outer nozzle 26, or to increase the diameters of the inner nozzle 25 and the outer nozzle 26. Therefore, it is possible to suppress the increase in the size of the ejector 1.

[0044] Furthermore, as shown in Figure 4, the nozzle guide 51 is formed in a rhombic shape when viewed from the inside of the outer nozzle 26. The nozzle guide 51 is positioned on the inner circumferential surface 26a upstream of the outer injection hole 32 (tip portion 42) of the outer nozzle 26, such that the direction of the diagonal of the major axis of the rhomb is parallel to the flow direction of the working fluid (i.e., the axis L3 direction of the outer nozzle 26). In this way, the upstream end 61 of the nozzle guide 51 (i.e., the right side in Figure 4) is formed in a shape that converges toward the upstream side. Also, the downstream end 62 of the nozzle guide 51 in the direction of the working fluid flow (left side in Figure 4) is formed in a shape that converges toward the downstream side.

[0045] As described above, according to this embodiment, the ejector 1 has a nozzle guide 51 that regulates the spacing of the outer injection holes 32.

[0046] In this way, the nozzle guide 51 restricts the spacing of the outer injection holes 32 (i.e., the spacing between the outer circumferential surface 41a of the tip portion 41 of the inner nozzle 25 and the inner circumferential surface 42a of the tip portion 42 of the outer nozzle 26), so that 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). As a result, the working fluid can be stably injected from the outer injection holes 32, the flow rate of the target fluid that flows due to the action of the working fluid is stabilized, and the target fluid can be flowed at the desired flow rate.

[0047] Furthermore, the nozzle guide 51 is positioned upstream of the outer injection hole 32.

[0048] In this way, since the nozzle guide 51 is not provided at the position of the outer injection hole 32 located at the tip 42, which is the smallest constriction portion of the outer nozzle 26, the cross-sectional area of ​​the flow path of the outer injection hole 32 does not decrease. Furthermore, the cross-sectional area of ​​the flow path between the inner nozzle 25 and the outer nozzle 26 can be made larger than when the nozzle guide 51 is provided at the position of the outer injection hole 32. In addition, even if the nozzle guide 51 acts as resistance to the flow of the working fluid and causes turbulence, it can be stabilized (rectified) at the outer injection hole 32, which is located downstream of the nozzle guide 51. As a result, the flow rate of the working fluid injected from the outer injection hole 32 does not decrease, and the positional relationship between the inner nozzle 25 and the outer nozzle 26 can be maintained at the desired positional relationship.

[0049] Furthermore, the upstream end 61 of the nozzle guide 51 is formed in a shape that converges toward the upstream side.

[0050] This prevents the nozzle guide 51 from acting as resistance to the flow of the working fluid. Therefore, it is possible to prevent the flow rate of the working fluid injected from the outer injection hole 32 from being reduced by the nozzle guide 51.

[0051] Furthermore, the downstream end 62 of the nozzle guide 51 is formed in a shape that converges toward the downstream side.

[0052] As a result, the nozzle guide 51 straightens the flow of the working fluid. Therefore, the straightened working fluid allows the target fluid to flow stably, thus stabilizing the flow rate of the target fluid.

[0053] As a variation, either the upstream end 61 or the downstream end 62 of the nozzle guide 51 may be formed in a shape that converges toward either the upstream or downstream side.

[0054] (Second example) Next, we will describe the second embodiment, explaining the differences from the first embodiment. I will omit the explanation of the common points.

[0055] In this embodiment, as shown in Figure 5, the nozzle guide 51 is positioned such that its axis Lg is inclined with respect to the flow direction of the working fluid (i.e., the direction of the axis L3 of the outer nozzle 26, the left-right direction in Figure 5). Here, the axis Lg is the line connecting the upstream end 61 and the downstream end 62 of the nozzle guide 51, as shown in Figure 5.

[0056] In this embodiment, since the axis Lg of the nozzle guide 51 is inclined with respect to the flow direction of the working fluid, the working fluid can be made to flow while swirling in the circumferential direction (up and down direction in Figure 5) of the inner nozzle 25 and outer nozzle 26 and ejected from the outer injection hole 32. As a result, the target fluid is made to flow more easily by the action of the working fluid ejected from the outer injection hole 32, and the amount of target fluid drawn into the diffuser 27 can be increased. Consequently, the mixed fluid of the target fluid and working fluid can be efficiently discharged from the discharge port 28.

[0057] (Third embodiment) Next, we will describe the third embodiment, explaining the differences from the first and second embodiments. The explanation of points common to the examples will be omitted.

[0058] In this embodiment, as shown in Figure 6, the height Hg of the nozzle guide 51 is made larger for nozzle guides 51 that are closer to the target fluid supply port 23 (i.e., the lower nozzle guide 51 in Figure 6). Here, height Hg refers to the radial width of the inner nozzle 25 and outer nozzle 26 in the nozzle guide 51.

[0059] In this way, by increasing the height Hg of the nozzle guide 51 for the nozzle guide 51 closer to the target fluid supply port 23, the inner nozzle 25 is eccentric to the outer nozzle 26 on the opposite side of the target fluid supply port 23 (i.e., the upper side of Figure 6), as shown in Figure 6. By eccentricating the inner nozzle 25 relative to the outer nozzle 26 in this way, the cross-sectional area of ​​the outer injection hole 32, as viewed from the axis L2 of the inner nozzle 25 (or the axis L3 of the outer nozzle 26), becomes larger the closer it is to the target fluid supply port 23 (i.e., the lower side of Figure 6).

[0060] Specifically, the heights Hg of the three nozzle guides 51 are set such that (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). As a result, 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, which are divided into three holes by the nozzle guides 51. The flow path 33 is a flow path formed between the outer circumferential surface 25a of the inner nozzle 25 and the inner circumferential surface 26a of the outer nozzle 26, and is a flow path that connects to the outer injection hole 32.

[0061] In this way, as shown in Figure 6, the axis L2 of the inner nozzle 25 is shifted to the side further from the target fluid supply port 23 (upper side in Figure 6) than the axis L3 of the outer nozzle 26, thereby forcibly eccentricating the inner nozzle 25 relative to the outer nozzle 26. This makes it possible to increase the flow rate of the working fluid injected from the portion of the outer injection hole 32 that is closer to the target fluid supply port 23. Therefore, it is possible to suppress the reduction in the flow rate of the working fluid injected from the outer injection hole 32 due to the influence of the flow of the target fluid from the target fluid supply port 23. Thus, the flow rate of the target fluid that flows due to the action of the working fluid can be maintained.

[0062] (Fourth embodiment) Next, we will describe the fourth embodiment, explaining the differences from the first to third embodiments, and omitting the explanation of the points that are common to the first to third embodiments.

[0063] In this embodiment, as shown in Figure 7, the spacing In between adjacent nozzle guides 51 in the circumferential direction of the inner nozzle 25 and outer nozzle 26 is increased as it approaches the target fluid supply port 23. As a result, the cross-sectional area of ​​the outer injection hole 32, as viewed from the axis L2 of the inner nozzle 25 (or the axis L3 of the outer nozzle 26), increases as it approaches the target fluid supply port 23.

[0064] Specifically, for the three nozzle guides 51, the distance In between the second nozzle guide 51-2 and the third nozzle guide 51-3, which is closer to the target fluid supply port 23, is larger than the distance In between the first nozzle guide 51-1 and the second nozzle guide 51-2, and the distance In between the first nozzle guide 51-1 and the third nozzle guide 51-3. As a result, for the flow path 33 (connected to the outer injection hole 32) which is divided into three 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.

[0065] This makes it possible to suppress the reduction in the flow rate of the working fluid injected from the outer injection port 32 due to the inflow of the target fluid, similar to the third embodiment. Therefore, the flow rate of the target fluid to be flowed by the action of the working fluid can be maintained.

[0066] (modified version) As a modified example, in the first to fourth embodiments, as shown in Figure 8, the suction port 71 of the diffuser 27 may be formed in an elliptical shape so that the opening area on the target fluid supply port 23 side is wider.

[0067] This makes it easier for the target fluid to be drawn in from the portion of the suction port 71 of the diffuser 27 that is on the side of the target fluid supply port 23. Therefore, 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.

[0068] It should be noted that the embodiments described above are merely illustrative examples and do not limit this disclosure in any way. Various improvements and modifications are possible without departing from the gist of the disclosure.

[0069] For example, the shape of the nozzle guide 51 may be a rectangular prism with a rhombic top and bottom, or a rectangular prism, cube, cylinder, or other prism shape.

[0070] Furthermore, although the above description uses a double-pipe nozzle with an inner nozzle 25 and an outer nozzle 26, a triple-pipe or more nozzle may also be used. [Explanation of symbols]

[0071] 1 Ejector 11 Main casing 25 Inner nozzle 26 Outer nozzle 27 Diffuser 28 Outlet 31 Inner injection hole 32 Outer injection hole 33 channels 41 (Tip of the inner nozzle) 42 (Tip of the outer nozzle) 51 Nozzle Guide 61 Upstream end 62 Downstream end 71 Suction port Lg (Nozzle guide) axis

Claims

1. The inner nozzle and An outer nozzle having the aforementioned inner nozzle on the inside, It has, A gap is provided between the inner nozzle and the outer nozzle. In an ejector that draws in a target fluid by negative pressure generated by a working fluid injected from the inside of the inner nozzle and / or the gap, and discharges the target fluid after it has merged with the working fluid, A gap regulating unit is provided in the gap to regulate the spacing of the gap, It has a target fluid supply port through which the target fluid is supplied, The inner circumferential surface of the outer nozzle comprises, in order from the tip side of the outer nozzle toward the upstream side in the flow direction of the working fluid, a portion with a constant inner diameter and a sloping portion with a gradually increasing inner diameter. The spacing restricting portion is provided upstream of the target fluid supply port in the flow direction of the working fluid, and is provided at the position of the inclined portion on the inner circumferential surface of the outer nozzle. An ejector characterized by the following.

2. In the ejector of claim 1, An outer injection hole is provided on the inside of the tip of the outer nozzle. The aforementioned spacing restricting portion is positioned upstream of the outer injection hole in the flow direction of the working fluid. An ejector characterized by the following.

3. In the ejector of claim 1 or 2, The upstream end of the gap restricting portion in the direction of the working fluid flow is formed in a shape that converges toward the upstream side. An ejector characterized by the following.

4. In the ejector of claim 1 or 2, The downstream end of the gap restricting portion in the direction of the working fluid flow is formed in a shape that converges toward the downstream side. An ejector characterized by the following.

5. In the ejector of claim 1 or 2, The cross-sectional area of ​​the gap, as viewed from the axial direction of the inner nozzle, is larger the closer it is to the target fluid supply port. An ejector characterized by the following.

6. In the ejector of claim 1 or 2, The spacing restricting portion is arranged such that the axis connecting the upstream end and the downstream end in the flow direction of the working fluid is inclined with respect to the flow direction of the working fluid. An ejector characterized by the following.

7. In the ejector of claim 1 or 2, The diffuser has a negative pressure generated by the working fluid that draws in the target fluid, combines the target fluid with the working fluid, and sends it to the outlet. The suction port of the diffuser is formed in an elliptical shape so that the opening area on the side of the target fluid supply port is widened. An ejector characterized by the following.

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