JPH01250000A - Ejector device - Google Patents

Abstract

PURPOSE:To improve the efficiency of operation by causing primary fluid to attract secondary fluid by flowing along a convex curved surface of a fluid path. CONSTITUTION:An insert body 4 constituting a portion of the inner peripheral side wall surface of a path along which primary fluid 12 jetted from a discharge port 11 flows at the narrowed portion 16 of a fluid path 9 is formed on the outer surface with a convex curved surface 19. The jetting direction of the primary fluid from the discharge port 11 is directed along the convex curved surface 19 at the jetting position. Thus, the effect of attracting secondary fluid is more fulfilled than that by prior device, so that the efficiency of operation is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an ejector device, and is intended to improve the operating efficiency thereof.

(Prior Art) Fig. 11 shows a conventional ejector device, in which primary fluid 12° is ejected at high speed from a discharge port 11' into a fluid passageway 9'' in an ejector body 5'. °
Negative pressure inside, low speed secondary fluid 15' from suction port 14°
It is something that attracts.

(Problem to be Solved by the Invention) In the conventional ejector device, since the speed difference between the primary fluid 12' and the secondary fluid 15' is large, the speed difference causes vortex generation at the 15° interface between the two fluids 12' and 15'. Based on this, the loss was large (and the operating efficiency was very poor at less than 15%), and its practical use was extremely limited.

The present invention aims to solve the technical problems of the prior art described above.

(Means for Solving the Problems) A feature of the present invention is that the primary fluid 12 is ejected from the discharge port 11 into the fluid passage 9 in the ejector body 5, and the secondary fluid 15 is ejected from the suction port 14. In the ejector device that sucks into the fluid passage 9, the primary fluid 12
The wall surface of the fluid passage 9 is formed into a convexly curved surface 19 so that the fluid flows along the wall surface of the fluid passage 9, and the primary fluid ejecting direction from the discharge port 11 is made along the convexly curved surface 19 at the ejecting position. The suction direction of the secondary fluid 15 from the suction port 14 is substantially parallel to the flow direction of the primary fluid 12 at the suction position.

(Function) The present invention utilizes the Coanda effect, in which when fluid is ejected along a wall surface, if the wall surface downstream of the ejection port is a convex curved surface, the jet flows along the convex curved surface.

That is, since the wall surface of the fluid passage 9 is a convex curved surface 19 and the primary fluid ejecting direction from the discharge port 11 is along the convex curved surface 19 at the ejection position, the Coanda effect causes the primary fluid to eject along the convex curved surface 19. The primary fluid 12 then flows. The pressure distribution when the ejected fluid flows along the wall surface is different from the pressure distribution when the ejected fluid is ejected into a fluid passage without a convex curved surface. Due to this difference in pressure distribution, it is thought that the suction effect of the secondary fluid will be better than that of the conventional one, and the ejector operating efficiency will be improved.

FIGS. 8, 9, and 10 show the results of numerical analysis conducted to confirm the above.

That is, as shown in FIGS. 9 and 10, consider a two-dimensional fluid passage surrounded by wall surfaces A and B, and primary fluid is ejected from the discharge port C into this fluid passage and secondary fluid is ejected from the suction port. The static pressure distribution on wall A is shown by numerical analysis when the next fluid is sucked and wall A is made into a convex curved surface as shown in Fig. 9, and when it is made flat as shown in Fig. 1O. be. 1st
The right side of the figure corresponds to the ejector according to the present invention in which a convex curved surface is formed in the fluid passage as shown in FIG. 9, and the square mark corresponds to the ejector according to the prior art in which the fluid passage does not have a convex curved surface as shown in FIG. From this, if a convex curved surface is formed in the fluid passage and the primary fluid is guided along it, the pressure in the area away from the convex curved surface in the direction perpendicular to the flow will be lower than in the conventional case, resulting in a suction effect on the secondary fluid. It turns out that you can make it larger.

The arrows in Figures 9 and 10 indicate the distribution of the velocity vector of the fluid, and the longer the arrow, the greater the flow velocity. 1st
It is faster than the one in Figure 0.

(Example) Embodiments of the present invention will be described below based on the drawings.

The ejector device 1 shown in FIGS. 1 to 3 includes an outer cylinder 2
, the inner cylinder 3 and the insert body 4 constitute an ejector main body 5.

The outer cylinder 2 has an annular cross section, and the left end face in FIG. 1 is closed, and a secondary fluid inlet 6 is provided near the closed end face, and the right end in the figure is open and serves as a fluid ratio lower. ing. The diameter between both ends gradually increases toward the center.

The insert body 4 is inserted between both ends of the outer cylinder 2 and is fixed by ribs 8, and its shape has a substantially elliptical cross section in the flow direction and a circular cross section perpendicular to the flow direction.

The inner cylinder 3 is connected to a primary fluid supply source (not shown) on the left end side in FIG. It is said that

A portion surrounded by the inner surface of the outer cylinder 2 and the outer surface of the insert body 4 is defined as a fluid passage 9. In addition, the part surrounded by the inner surface of the right end of the inner cylinder 3 in FIG. 1 and the outer surface of the insert body 4 is the nozzle hole 10.
The primary fluid 12 is ejected from the discharge port 11 of the injection hole 10 into the fluid passage 9. Further, a portion surrounded by the outer surface of the right end of the inner cylinder 3 in FIG.

The fluid passage 9 extends downstream (rightward in FIG. 1) toward the contraction section 1.
6. The throat portion 17 and the differential user portion 18 are formed in this order. In the flow contraction section 16, the passage cross-sectional area is gradually decreased as it goes downstream, the throat section 17 has a constant passage cross-sectional area, and the passage cross-sectional area of the differential user section 18 is gradually increased as it goes downstream.

In order that the primary fluid 12 ejected from the discharge port 11 flows along the passage wall surface in the contracted flow section 16 of the fluid passage 9, the outer surface of the insert body 4 constituting the inner circumferential wall surface of the passage at that portion is convex. It is assumed that the curved surface is 19. Further, the direction in which the primary fluid is ejected from the discharge port 11 is along the convex curved surface 19 at the ejection position. Furthermore, in this embodiment, the outer surface of the insert body 4 and the inner surface of the inner cylinder 3 constituting the nozzle hole 10 are made flat and parallel to each other, so that no turbulence occurs in the jet flow and loss is reduced. There is. As a result, the discharge port 11
In the contraction section 16, the primary fluid 12 ejected from the insert body 4 flows as a so-called film flow along the convex curved surface 19 on the outer surface of the insert 4 due to the Coanda effect.

Then, by ejecting the primary fluid 12, the inside of the fluid passage 9 becomes negative pressure, and the secondary fluid 15 is efficiently sucked from the suction port 14. The suction direction of the secondary fluid 15 from this suction Ct14 is made approximately parallel to the flow direction of the primary fluid 12 at the suction position by making the outer surface of the insert body 4 on the inner surface of the outer cylinder 2 approximately parallel. ing. Thereby, the primary fluid 12 and the secondary fluid 15 do not intersect with each other, and losses due to vortex generation can be reduced.

Note that if the radius of curvature 12 of the convex curved surface 19 is not sufficiently large with respect to the axial length of the contraction section 16, there is a risk that the primary fluid 12 may separate without following the convex curved surface 19. The radius of curvature R is set to be large enough to prevent peeling.

The primary fluid 12 then flows from the contraction section 16 to the throat section 17.
In the throat portion 17 , the wall surface of the fluid passage 9 is made a flat surface so that the Coanda effect along the wall surface of the fluid passage 9 disappears when the fluid passage 9 reaches . As a result, the throat portion 17
, the primary fluid 12 is separated from the wall surface and the secondary fluid 15
What used to be a flow with two high and low pressures now becomes a flow with a constant pressure throughout. Thereafter, the pressure energy of the mixed fluid is increased in the diffuser section 18 and the mixed fluid is discharged from the outlet lower.

Furthermore, the ribs 8 have the effect of suppressing naturally occurring weak swirling flows. The length and number of ribs 8 are appropriately selected depending on the effect.

Note that, as shown in FIG. 4, the cross-sectional shape of the discharge port 11 and the suction port 14 in the direction perpendicular to the flow may be elliptical.

FIGS. 5 and 6 show ejector devices 1 according to different embodiments, in which an ejector body 5 includes an outer cylinder 2 and an inner cylinder 3.
is configured.

The outer cylinder 2 has an annular cross section, and the left end face in FIG. 5 is closed, and a connection port 2 with a primary fluid supply source is provided near the closed end face.
0 is provided, and the right end in the figure is open to serve as a fluid outlet lower. A fluid passageway 9 is formed between both ends, with the diameter gradually decreasing toward the center.

The inner cylinder 3 has a secondary fluid suction port 6 on the left end side in FIG.
The right end side is inserted and fixed into the outer cylinder 2, and the right end is opened and serves as a suction port 14 for the secondary fluid 15.

A portion surrounded by the inner surface of the outer cylinder 2 and the right outer surface of the inner cylinder 3 in FIG. Ru. Further, ribs 8 are provided in the fluid passage. In addition, rib 8
You may provide more than one.

The fluid passage 9 is formed in the order of the contraction part 16, the throat part 17, and the diffuser part 18 toward the downstream, as in the above embodiment. In the contraction section 16,
The inner surface of the outer cylinder 2 has a convex curved surface 19. This results in
In the contraction section 16, due to the Coanda effect, the discharge port 1
The primary fluid 12 ejected from the primary fluid 1 flows along the convex curved surface 19 thereof. The flow of the primary fluid 12 along this convex curved surface 19 creates a negative pressure in the fluid passage 9, and the secondary fluid 15 is efficiently sucked from the suction port 14. Note that the ejecting direction of the primary fluid 12, the suction direction of the secondary fluid 15, the fluid mixing effect at the throat section 17 having a flat wall surface, the effect of the ribs 8, and the function of the diffuser section 18 are the same as in the above embodiment. .

If the flow rate of the primary fluid 12 is the same between the embodiment shown in FIG. 1 and the embodiment shown in FIG. Since the contact area with the wall surface before ejecting from the outlet is small, friction loss is also small, which is preferable.

FIG. 7 shows an ejector device 1 according to a further different embodiment, in which an ejector main body 5 is composed of an outer cylinder 2, an inner cylinder 3, and a base 20.

The outer cylinder 2 is provided with a secondary fluid inlet 6 near the closed surface at the left end in the figure, and the right end is disk-shaped.

The inner cylinder 3 is connected to a primary fluid supply source at its left end, and inserted and fixed into the outer cylinder 2 at its right end, and has a disc-shaped tip.

The base plate 20 has a disc shape, is arranged so as to face the right end of the inner and outer cylinders 2.3, and is fixed to the inner and outer cylinders 2.3 via ribs (not shown) or the like. As a result, a nozzle hole 10 and a discharge port 11 are formed between the tip of the inner cylinder 3 and the base 20, and a fluid passage 9 is formed between the tip of the outer cylinder 2 and the base 20. Further, a convex curved surface 19 is provided on the base 20 forming the fluid passage 9. The other configurations are the same as in each of the above embodiments and are designated by the same reference numerals.

(Effect of the invention) According to the ejector device according to the present invention, the primary fluid is
Because it sucks the secondary fluid by flowing along the convex curved surface of the fluid passage, its operating efficiency is improved compared to the conventional method, which sucks the secondary fluid by ejecting the primary fluid into the space. can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an ejector device according to an embodiment of the present invention, FIG. 2 is a sectional view taken along line A-A in FIG. 1, FIG. 3 is an enlarged sectional view of the main part of FIG. A sectional view corresponding to FIG. 2 of an embodiment in which the discharge port and suction port are different from the embodiment shown in FIG. 1, and FIG. 5 is a sectional view corresponding to the embodiment shown in FIG. A sectional view of the ejector device, FIG. 6 is a sectional view taken along line B-B in FIG. 5, FIG. 7 is a sectional view of the ejector device according to the conventional example, FIG. 10 is a diagram showing a fluid velocity vector of an ejector according to the present invention, FIG. 10 is a diagram showing a fluid velocity vector of an ejector according to a conventional example, and FIG. 11 is a cross-sectional view of an ejector device according to a conventional example. 5... Ejector body, 9... Fluid passage, 11.
...Discharge port, 12...Primary fluid, 14...Suction port,
15...Secondary fluid, 19...Convex curved surface. Patent applicant: Kobe Steel, Ltd.■, Case indication: 1988 Patent Application No. 77727 2, Name of the invention: Ejector device 3, Relationship with the amended person case: Patent applicant (119): Kobe Co., Ltd. Steelworks 4, Agent ◎577, 1013 Mikuriya, Higashiosaka City, Osaka Prefecture Telephone: 06 (7B2) 6917/6918 6, Subject of amendment/drawings (Fig. 9, Fig. 1θ) 7. Contents of amendment (1) Figures 9 and 10 of the drawings will be corrected as shown in the attached sheet.

Claims (1)

[Claims] (1) The discharge port 1 is connected to the fluid passage 9 in the ejector body 5.
In an ejector device that sucks a secondary fluid 15 from a suction port 14 into a fluid passage 9 by ejecting a primary fluid 12 from a suction port 14, the wall surface of the fluid passage 9 is made such that the primary fluid 12 flows along the wall surface of the fluid passage 9. The suction port 14 has a convex curved surface 19, and the primary fluid ejecting direction from the discharge port 11 is along the convex curved surface 19 at the ejection position.
An ejector device characterized in that the suction direction of the secondary fluid 15 from the ejector device is substantially parallel to the flow direction of the primary fluid 12 at the suction position.