JPH0448921A - Ejector - Google Patents

Abstract

PURPOSE:To still enhance the contact mixing efficiency of the first and second liquids by providing the jet orifice of the second liquid inside a nozzle and injecting the second liquid therefrom. CONSTITUTION:The water supplied under pressure through the piping 12 on the side of a submerged pump is once throttled when it passes through a contraction nozzle 14 to be forcibly ejected at high speed from the orifice provided to the leading end of the nozzle 14. Negative pressure is generated in a negative pressure chamber 18 by the ejected water and the open air is sucked by this negative pressure through a suction pipe 22 and a suction port 20, and discharged through a discharge pipe part 24 along with the jet stream of water in a mixed state. In this nozzle part, water and air are brought to a contact state over a wide contact area. The air sucked from the suction port 20 is brought into contact with the water stream from the nozzle 14 outside of said water stream and water and air are well mixed in a contact state.

Description

Detailed Description of the Invention (Industrial Application Field) This invention is applicable to gas-liquid contact mixing in purifiers, 112 stirring,
The present invention relates to ejectors that are widely used for other purposes.

(Background of the Invention and Problems to be Solved) An ejector that ejects a first fluid from a nozzle at high speed, sucks a second fluid from an inlet using the entraining action of the ejected flow, and discharges it together with the first fluid is a purifier. *It is widely used for gas-liquid mixing or stirring in AI, or as a vacuum generator in other fields, a contact device H for gas absorption, etc.

FIG. 4 shows an example of an ejector commonly used in the past. As shown in the figure, in the case of this ejector, water sucked in by a submersible pump 100 is ejected at high speed from a contraction nozzle 102 to create a negative pressure. Negative pressure is generated in the chamber 104, and the negative pressure causes air introduced through the suction pipe 106 and suction 1j l O8 to be sucked in and discharged through the discharge pipe section 110 together with the wood jet stream. .

However, this ejector has a problem in that the contact mixing efficiency between the first fluid ejected from the nozzle 102 and the second fluid sucked through the suction port 108 is still insufficient.

The present invention has been made to solve such problems, and its gist is to eject a first fluid from a nozzle,
The ejector sucks and discharges the second fluid from the suction port by the entrainment action of the ejected flow, and the ejector is provided with one or more ejection ports for ejecting the second fluid inside the nozzle.

(Action and effect of invention) ffi4r! In the conventional ejector shown in No. 4, the second fluid (usually gas) sucked in from suction 0108 is brought into contact with the outer periphery of the first fluid (usually liquid) ejected from the constriction nozzle 102. .

However, in the ejector of the present invention, the second fluid jet port is provided inside the nozzle, and the second fluid is jetted from there. , the first fluid and the second fluid are also brought into contact within the jet flow.

This has the effect of further increasing the contact mixing efficiency between the first fluid and the second fluid.

By the way, when different fluids are brought into contact, the contact mixing efficiency increases as the contact area increases. However, in the case of an ejector, as the contact area increases, the ejection flow of the first fluid for sucking the second fluid slows down, and as a result, the amount of second fluid sucked from the suction port decreases. There is a possibility that sufficient contact and mixing between the first fluid and the second fluid will not occur.

In this respect, the ejector of the present invention is! It has been confirmed that the contact area between the first fluid and the second fluid can be increased and the contact mixing efficiency thereof can be increased without particularly reducing the intake amount of the second fluid.

In the present invention, it is desirable that the jet U is formed inside the nozzle in a ring shape and concentric with the nozzle.

In this way, a ring-shaped flux of the second fluid is generated inside the flux of the first fluid from the nozzle, and as a result, the flux of the first fluid and the flux of the second fluid intersect. Therefore, their contact area is effectively increased.

(Example) Next, an example in which the present invention is applied to an ejector for contact mixing of water and air will be described in detail based on the drawings.

In 9N156, 10 is its ejector.

It has a pipe 12 extending to the submersible pump side. Piping 12
A convergence nozzle 14 is provided at the tip of the nozzle, and a casing 16 is provided to surround the trickle nozzle 14. The interior of the casing 16 is a negative pressure chamber 18, and the casing 16
Air is being sucked inside.

Note that 24 is a discharge pipe section for discharging the jet stream.

Inside the contraction nozzle 14, as shown in FIG. 2, an outer tube 26 and an inner tube 9f28 are arranged concentrically, and a ring-shaped jet is formed by them to blow out air. Exit is configured. And those outer W26 and inner pipe 2
An introduction pipe 29 is connected to the proximal end of the ring-shaped space formed by 8 in both upper and lower positions, and air is introduced into the ring-shaped space through these introduction pipes 29.

Here, an outer pipe 26 and an inner pipe 28 forming a ring-shaped spout
They are said to have different lengths. That is, inner tube 2
8 has its tip located at the same position as the tip of the trickle nozzle 14, while the outer tube 26 protrudes into the negative and positive chamber 18 by a certain length (cross) than the tips of the constriction nozzle 14 and the inner tube 28. I'm forced to.

Next, the operation of the ejector of this example will be explained.

When the wood that is pressure-fed through the pipe v12 on the submersible pump side passes through the contraction nozzle 14, it is ejected forcefully at high speed from the once narrowed upper tip opening. This jet flow generates negative pressure in the negative pressure chamber 18, and the negative pressure sucks air from the atmosphere through the suction pipe 22 and the inlet 20, and the air is mixed with the jet flow of water and passes through the discharge pipe section 24. be discharged.

In the case of the ejector of this example, a ring-shaped ejection port is provided inside the contraction nozzle 14, and air is also ejected from the ring-shaped ejection port.

That is, in the ejector lO of this example, the water pumped through the pipe 12 is ejected from the tip of the inner pipe 28 in a circular cross-section, and also from between the outer pipe 26 and the pipe wall of the contraction nozzle 14 in a ring shape. is ejected. Between these two water fluxes, the air introduced through the introduction pipe 29 is ejected from the ejection opening formed by the inner pipe 28 and the outer pipe 26 in a ring shape.

As a result, in the ejector 10 of this example, the contraction nozzle 1
A ring-shaped air flux is formed inside the water flux from Nozzle 4, and water and air are brought into contact with each other over a wide contact area in this nozzle portion. At the same time, the air sucked in through the suction port 20 is brought into contact with the water flux from the nozzle 14 on the outside thereof, whereby the water and air are brought into good contact and mixed.

Table 1 shows the KLa value when gas-liquid mixing is performed using the ejector IO of this example, in comparison with that of a conventional ejector. Here, 1 is the overall oxygen transfer capacity coefficient, and is an index indicating the amount of dissolved rIg element.

(Left below) Into the liquid As can be seen from the results in Table 1, in the case of the ejector of this example,
Compared to the conventional ejector, the KLa value is significantly increased even though the intake air 1 is almost the same.

In the present invention, it has been confirmed that better results can be obtained by making the outer tube 26 protrude as described above. FIG. 3 specifically shows this, and the horizontal axis shows the outer tube 26.
The vertical axis shows the oxygen absorption efficiency at a water temperature of 20°C.

From this figure, it can be seen that the oxygen absorption efficiency is increased by making the diameter larger than O, that is, by making the outer tube 26 protrude, and that the oxygen absorption efficiency is particularly good when the diameter is about 20 to 300.

In the present invention, it is preferable that the contraction nozzle 14 is constricted in the middle, and the outer tube 26. Inner tube 2
As for 8, it is desirable to form it into a straight tube shape, and furthermore, the introduction pipe 28 may be made of a single piece of wood, but it should be placed in two symmetrical positions (vertical or horizontal symmetrical positions) to prevent deflection due to the introduced air. The distance between the outer tube 26 and the inner tube 28 is desirably greater than or equal to lam and less than or equal to 5. The distance from the tip of the contraction nozzle 14 to the inlet portion 30 of the discharge pipe section 24 is desirably about 3 to 5 times the inner cross-sectional area of the tube 28.
It has been confirmed through experiments that it is desirable to set the ratio to about 50.1.

Although the embodiments of the present invention have been described above in detail, the present invention can be configured in other forms.

For example, in the case of supernatant, the ejection port of the second fluid is formed into a ring shape concentric with the contraction nozzle 14, and only one is provided.
A plurality of such ring-shaped jet ports may be provided concentrically with the contracting flow nozzle 14, or they may be formed in a different shape than the ring shape, or provided at a position different from that of the supernatant. It is also possible.

Further, depending on the case, the suction pipe 22 and the suction port 20 in the above embodiment may be omitted, and the ejector of the present invention can be used not only as a gas-liquid mixing device of a purification device but also as another gas-liquid mixing device. Alternatively, it can be used for various other purposes, and can be configured with various modifications based on the knowledge of those skilled in the art without departing from the spirit thereof.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 are a longitudinal cross-sectional view and a cross-sectional view of a main part of an ejector according to an embodiment of the present invention, respectively.
The figure shows the relationship between the protruding length of the outer tube and the oxygen absorption efficiency in the ejector, and FIG. 4 is a schematic diagram showing an example of the conventional ejector. lO: Ejector 14: Contraction nozzle 20: Inlet
22: Suction pipe 26: Outer pipe 28: Inner pipe 29: Introductory pipe diagram (mm)

Claims (2)

[Claims] (1) In an ejector that ejects a first fluid from a nozzle, and sucks and discharges a second fluid from a suction port by the entrainment action of the ejected flow, a unit that ejects the second fluid into the inside of the nozzle. Alternatively, an ejector characterized by being provided with a plurality of ejection ports. (2) The ejection port ejects the second fluid in the same direction as the ejection flow of the first fluid, and is formed in a ring shape and concentric with the nozzle. The ejector according to item (1).