KR101200284B1 - Performance improvement of the vacuum ejector system using a shock wave generator - Google Patents

Abstract

PURPOSE: An apparatus for improving the performance of a vacuum ejector with a shock wave generator is provided to effectively improve the vacuum degree of a vacuum chamber as the outside air does not flow into the ejector. CONSTITUTION: An apparatus(10) for improving the performance of a vacuum ejector comprises a vacuum chamber(20), a nozzle(30), a duct(40), and a shock wave generator(100). The inside of the vacuum chamber is maintained at a lower pressure than atmospheric pressure. The nozzle guides the gas discharged from one open side of the vacuum chamber to the other side of the vacuum chamber. The diameter of the nozzle is gradually reduced toward the side that the gas is discharged. The duct is connected to the other open side of the vacuum chamber. The duct discharges the high pressure gas to the outside. The shock wave generator is installed inside the duct, and recovers the pressure of outflow gas and blocks outside air from flowing in the ejector. [Reference numerals] (31) Engine

Description

PERFORMANCE IMPROVEMENT OF THE VACUUM EJECTOR SYSTEM USING A SHOCK WAVE GENERATOR}

The present invention relates to a vacuum ejector performance improvement device using a shock wave generator, and more particularly, to install a shock wave generator (SHOCK WAVE GENERATOR) inside the duct to improve or maintain the vacuum in the vacuum chamber when the vacuum ejector is used, By reducing the excessive pressure drop generated in the part, it is possible to prevent the outside air from flowing into the ejector, thereby effectively improving the vacuum degree of the vacuum chamber, and by a plurality of shock waves generated in the mixing part and the diffuser part of the ejector In addition, it is possible to effectively recover the pressure of the gas flowing into the ejector outlet, thereby reducing the flow velocity at the ejector outlet, thereby reducing aerodynamic noise generated by the high-speed flow, thereby reducing the burden of the silencer, as well as structural vibration of the device. You can also reduce.

In general, an ejector is a device that compresses and transfers a low pressure fluid to a higher pressure by injecting a high pressure driving fluid into a nozzle and exchanging a momentum with a low pressure fluid around the jet. Condensor) has been used as a pump for scavenging pumps, and its scope of use has been gradually expanded to vacuum pumps, exhaust pumps and thermal compressors.In recent years, combustion equipment, natural gas equipment, food manufacturing equipment, air conditioning facilities, drying and It is widely applied from deodorizers and semiconductor devices to various chemical fields, and also has many applications such as jet pumps, blast nozzles for metal processing, and advanced simulation equipment for rocket engines, which are installed for emergency use in hydroelectric power plants. It is also applied to the device. In recent years, the ejector system has been applied to hydrogen fuel cells of automobiles and has been widely used.

The ejector is divided into subsonic ejector, sonic and supersonic ejector according to the type of the driving fluid applied to the primary nozzle and the shape of the nozzle, and subdivided into the single nozzle method and the multi-stage nozzle method according to the number of the driving nozzles. In terms of the overall structure, the nozzle is mostly composed of a nozzle, a mixing section, and a diffuser, and since the ejector device does not have any rotating parts or active parts therein, there is little trouble due to the operation of the device. Despite its compact size, it has the feature of compressing and transporting a large amount of fluid.

The ejector is proposed in Korean Patent Publication No. 10-2005-0018404.

In the case of vacuum ejectors, it is important to effectively increase and maintain the degree of vacuum inside the vacuum chamber. In order to improve the performance of these ejectors, the cost of equipment increases and a lot of inconveniences are caused by replacement. In addition, in order to reduce the pressure / speed of the high speed / pressure gas discharged from the nozzle inside the vacuum ejector, and to reduce the pressure to atmospheric pressure, the cost of additional equipment such as a duct and a silencer installed at the rear end of the ejector may occur. do.

Therefore, there is a need to improve this.

The present invention has been made to solve the above problems, by mounting a shock wave generator (shock shock generator) inside the duct (block) to easily block the backflow of the outside air generated from the downstream of the ejector to reduce the vacuum degree of the vacuum chamber The present invention relates to an apparatus for improving ejector performance economically and performancely, which can effectively improve the pressure energy of the gas converted by the ejector and effectively reduce the pressure energy to the atmospheric pressure.

The vacuum ejector performance improving device using the shock wave generator according to the present invention includes: a vacuum chamber having an internal pressure lower than atmospheric pressure and having one side arranged in a straight line, and the other side being opened; A nozzle which guides the gas injected into the other side of the vacuum chamber and decreases in diameter toward the discharge side of the vacuum chamber, a duct connected to the other open side of the vacuum chamber and opened to the outside to guide the discharge of high pressure gas into the atmosphere; And a shock wave generator (SHOCK WAVE GENERATOR) provided inside the duct to restore pressure of the outflow gas and block inflow of external air.

The shock wave generator may be provided on the inner surface of the duct continuously or discontinuously along the circumferential trajectory.

The shock wave generator may be provided in plurality in the axial direction of the duct.

The shock wave generator preferably forms a vertical surface to partially expand in the duct due to the impingement of gas injected at high pressure.

The shock wave generator preferably forms an inclined surface that is inclined from the end of the vertical surface to the inner surface of the duct along the gas flow direction.

As described above, the vacuum ejector performance improving apparatus using the shock wave generator according to the present invention has a shock wave generator (SHOCH WAVE GENERATOR) on the inside of the duct (unlike the prior art) excessive pressure generated in the mixing section of the ejector By reducing the drop, it is possible to prevent outside air from flowing into the ejector, thereby effectively improving the vacuum degree of the vacuum chamber, and leaking to the ejector outlet by a plurality of shock waves generated at the mixing part and the diffuser part of the ejector. It can effectively recover the pressure of the gas to reduce the aerodynamic noise generated by the high-speed flow as it reduces the flow rate at the ejector outlet can reduce the burden of the silencer.

1 is a partial cutaway view of a vacuum ejector performance improving apparatus using a shock wave generator according to an embodiment of the present invention.
2 is a cross-sectional view of a vacuum ejector performance improving apparatus using a shock wave generator according to an embodiment of the present invention.
3 is a cross-sectional view of a vacuum ejector performance improving apparatus using a shock wave generator according to another embodiment of the present invention.
Figure 4 is a data showing the pressure change of the vacuum ejector performance improving apparatus using a shock wave generator according to the present invention.

Hereinafter, an embodiment of a vacuum ejector performance improving apparatus using a shock wave generator according to the present invention will be described with reference to the accompanying drawings. In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, terms to be described below are terms defined in consideration of functions in the present invention, which may vary according to the intention or convention of a user or an operator. Therefore, the definitions of these terms should be made based on the contents throughout the specification.

1 is a partial cutaway view of a vacuum ejector performance improving apparatus using a shock wave generator according to an embodiment of the present invention, Figure 2 is a cross-sectional view of the vacuum ejector performance improving apparatus using a shock wave generator according to an embodiment of the present invention.

3 is a cross-sectional view of a vacuum ejector performance improving apparatus using a shock wave generator according to another embodiment of the present invention.

Figure 4 is a data showing the pressure change of the vacuum ejector performance improving apparatus using a shock wave generator according to the present invention.

1 and 2, the vacuum ejector performance improving apparatus 10 using the shock wave generator according to an embodiment of the present invention is applied to industrial or aviation.

When the vacuum ejector performance improving apparatus 10 according to an embodiment of the present invention is applied to aviation, the vacuum ejector performance improving apparatus 10 may convert a flow having a low momentum around as a high speed primary flow. It is a facility that compresses through exchange and transports to a high pressure discharge part. It is a device that mixes and transfers two gas (fluid) streams with a simple mechanical configuration.

Mechanical structures of the vacuum ejector performance improving apparatus 10 include a vacuum chamber 20, a nozzle 30, a duct 40, and a shock wave generator 100.

The interior of the vacuum chamber 20 should be maintained at a pressure lower than atmospheric pressure.

In addition, the vacuum chamber 20 is formed so that one side and the other side arranged in a straight line is opened. That is, the vacuum chamber 20 has an inlet 22 on one side and a discharge port 24 on the other side. In addition, the inlet port 22 and the outlet port 24 are disposed in a straight line so as not to disturb the flow of the discharged gas.

Of course, the vacuum chamber 20 can be modified in various shapes and various materials.

In addition, the vacuum chamber 20 is formed so that one side and the other side arranged in a straight line is opened. That is, the vacuum chamber 20 has an inlet 22 on one side and a discharge port 24 on the other side. In addition, the inlet port 22 and the outlet port 24 are arranged in a straight line so as not to disturb the flow of the gas discharged.

In addition, the nozzle 30 is provided at one open side of the vacuum chamber 20, that is, the inlet 22. At this time, when the nozzle 30 is inserted into the inlet 22, the gap between the nozzle 30 and the vacuum chamber 20 is sealed. Of course, the nozzle 30 is fixedly installed at the inlet 22 by various methods.

The nozzle 30 is formed to be open to both sides along the axial direction. Thus, high pressure gas is conveyed at high speed through the nozzle 30, the vacuum chamber 20, and the duct 40.

Accordingly, the air inside the vacuum chamber 20 is mixed with the high-pressure gas discharged from the nozzle 30 in the initial atmospheric pressure state and discharged to the outside along the duct 40, so that the inside becomes a pressure lower than the atmospheric pressure. Thus, the inside of the vacuum chamber 20 maintains the low pressure state close to the vacuum.

Thus, the nozzle 30 is provided with an engine 31 for forming and ejecting a high pressure jet stream.

In addition, the nozzle 30 is fixedly installed at the inlet 22 of the vacuum chamber 20 and gradually decreases in diameter from the mixing portion 32 having the same diameter along the axial direction, and the mixing portion 32 along the axial direction. It consists of a diffuser 34.

The mixing part 32 is a part for guiding the gas injected at high pressure by the engine 31 to be transported straight. In addition, the diffuser 34 is a portion of which diameter decreases toward the discharge side of the gas so as to decrease the pressure by increasing the velocity of the gas to be injected.

The gas ejected through the diffuser 34 is straight in the vacuum chamber 20 in a vacuum state and flows toward the discharge port 24.

On the other hand, the duct 40 is connected to the vacuum chamber 20 so as to match the other open side of the vacuum chamber 20, that is, the discharge port 24. The duct 40 is connected to the vacuum chamber 20 so as to be disposed in line with the discharge port 24. In this case, the duct 40 may be fixed to the vacuum chamber 20 by welding or may be integrally formed in the vacuum chamber 20.

And the duct 40 is open to both sides. Therefore, the high-pressure gas passes through the duct 40 through the discharge port 24 to form a shock wave and the pressure is lowered.

In particular, one side of the duct 40 is connected to the vacuum state inside the vacuum chamber 20, the other side is connected to the outside air of 1 atm. Thus, the high pressure gas is gradually reduced to atmospheric pressure while passing through the duct 40. For this reason, the gas blown out from the duct 40 does not generate noise due to the pressure difference between the outside air. The diameter of the duct 40 is preferably made of the same diameter for even distribution of the shock wave.

As the shock wave of the jet stream increases the number of diffuse reflections inside the duct 40, the time until the pressure of the gas is reduced to atmospheric pressure is shortened.

In particular, a shock wave generator 100 is provided inside the duct 40.

The shock wave generator 100 protrudes a plurality of the inside of the duct 40 serves to promote the diffuse reflection of the jet stream.

In particular, a plurality of shock wave generators 100 are provided along the circumferential trajectory on the inner surface of the duct 40. That is, the shock wave generator 100 is provided continuously or discontinuously along the circumferential trajectory of the duct 40. Of course, the number of shock wave generators 100 is not limited. For convenience, the shock wave generator 100 is illustrated as being provided with four at regular intervals along the inner surface of the duct 40.

In addition, a plurality of shock wave generators 100 are provided on the inner side along the axial direction of the duct 40. That is, the shock wave generator 100 is provided to be spaced apart at regular intervals along the axial direction of the duct 40. Of course, the number of shock wave generators 100 is not limited. For convenience, the shock wave generators 100 are shown arranged in three rows at uniform intervals along the axial direction of the duct 40. Therefore, four shock wave generators 100 are provided along the circumferential direction of the duct 40 and are arranged in three rows along the axial direction of the duct 40.

On the other hand, when the diameter of the duct 40 is larger than the set value, outside air is introduced into the vacuum chamber 20 by the gap between the jet stream and the duct 40. This is because the pressure inside the vacuum chamber 20 is in a vacuum state lower than atmospheric pressure, and the wavelength (amplitude) of the jet stream is small.

Thus, the shock wave generator 100 forms a vertical plane 110 on the side facing the nozzle 30 to partially expand in the duct 40 due to the impingement of gas injected at high pressure.

That is, the jet stream is expanded at the front side of the shock wave generator 100 arranged in the circumferential direction due to the occurrence of resistance such as hitting the vertical plane (110). Thus, the jet airflow expands to fill the entire inside of the duct 40. As a result, the outside air is blocked from flowing into the vacuum chamber 20.

In particular, since the shock wave generator 100 is arranged in a plurality of rows along the axial direction of the duct 40, as the jet air flow expands by the number of columns, the inflow of outside air into the vacuum chamber 20 may be completely blocked.

In addition, the shock wave generator 100 forms an inclined surface 120 that is inclined from the end of the vertical surface 110 to the inner surface of the duct 40 in the flow direction of the gas. This is to prevent the generation of vortices by expanding the jet stream flows along the inclined surface 120 of the shock wave generator 100.

Meanwhile, referring to FIG. 3, the vacuum ejector performance improving apparatus 10 using the shock wave generator according to another embodiment of the present invention applies the shock wave generator 100 as an orifice type.

That is, the shock wave generator 100 is formed in a ring shape in the circumferential direction on the inner surface of the duct 40, and is spaced apart by a predetermined interval along the axial direction of the duct 40.

Accordingly, a plurality of shock wave generators 100 are projected inside the duct 40 to promote diffuse reflection of the jet stream.

In addition, as shown in Figure 4, the high-pressure gas is ejected at high speed by the ejector to reduce the pressure, the shock wave is generated during the suction and mixing of the gas in the vacuum chamber 20 in the mixing section, due to the shock wave generator 100 It can be seen that the gas recovers the pressure.

In addition, the flow rate can be reduced at the gas outlet to reduce noise and vibration.

In other words, the shock wave generator 100 is installed inside the duct 40 to improve or maintain the degree of vacuum in the vacuum chamber 20, thereby reducing the excessive pressure drop generated in the mixing part of the ejector, so that the outside air is ejected. Since it can be prevented from entering the inside, it is possible to effectively improve the degree of vacuum of the vacuum chamber 20, and the pressure of the gas flowing out of the ejector outlet by a plurality of shock waves generated in the mixing section and the diffuser section of the ejector It can be effectively restored.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. I will understand. Therefore, the true technical protection scope of the present invention will be defined by the claims below.

10: Improved performance of vacuum ejector using shock wave generator
20: vacuum chamber 21: vacuum pump
22: inlet port 24: outlet port
30: nozzle 32: mixing section
34: diffuser 40: duct
100: shock wave generator 110: vertical plane
120: slope

Claims (5)

A vacuum chamber having an internal pressure lower than atmospheric pressure and having one side and the other side arranged in a straight line;
A nozzle for inducing discharge of the gas injected at a high pressure from the open side of the vacuum chamber to the other side of the vacuum chamber, and decreasing the diameter toward the discharge side of the gas;
A duct connected to the other open side of the vacuum chamber and opened to the outside to guide the discharge of high pressure gas into the atmosphere; And
It includes a shock wave generator (SHOCK WAVE GENERATOR) is provided inside the duct to recover the pressure of the outflow gas, and block the inflow of outside air,
The shock wave generator is a vacuum ejector performance improvement device using a shock wave generator, characterized in that provided on the inner surface of the duct continuously or discontinuously along the circumferential trajectory.
delete The method of claim 1,
And a plurality of shock wave generators provided on the inner side in the axial direction of the duct.
The method of claim 1,
The shock wave generator is a vacuum ejector performance improvement device using a shock wave generator, characterized in that for forming a vertical plane to partially expand in the interior of the duct due to the gas injected at high pressure.
The method of claim 4, wherein
The shock wave generator improves the performance of the vacuum ejector using a shock wave generator, characterized in that for forming a slope inclined from the end of the vertical plane to the inner surface of the duct along the flow direction of the gas.

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