CN106064122B

CN106064122B - Sawtooth jet type evacuator

Info

Publication number: CN106064122B
Application number: CN201510198077.9A
Authority: CN
Inventors: 刘友宏
Original assignee: In Suzhou Energy Saving And Environmental Protection Equipment Co Ltd
Current assignee: In Suzhou Energy Saving And Environmental Protection Equipment Co Ltd
Priority date: 2015-04-24
Filing date: 2015-04-24
Publication date: 2019-12-24
Anticipated expiration: 2035-04-24
Also published as: CN106064122A

Abstract

The invention discloses a supersonic sawtooth nozzle and a sawtooth jet type evacuator device provided with the same. The supersonic sawtooth nozzle comprises an inlet section, a nozzle throat, a nozzle outlet section and a triangular or concave fan-shaped modification of the nozzle outlet trailing edge. The sawtooth jet type evacuator device provided with the supersonic sawtooth nozzle comprises: 1) a main flow fluid conduit inlet section; 2) a supersonic wave serrated nozzle; 3) a suction chamber and a secondary inlet connected to the suction chamber; 4) a mixing plenum. The hybrid diffusion chamber includes: 1) the mixing section consists of an inlet part and a convergence part; 2) a throat; 3) and a diffusion section. The invention has high injection coefficient and working efficiency in mechanism and effect, and can greatly save energy and reduce consumption.

Description

Sawtooth jet type evacuator

Technical Field

The invention belongs to the technical field of equipment in industries such as petroleum, petrifaction, chemical engineering, metallurgy, electric power, refrigeration, pharmacy, seawater desalination and the like, and particularly relates to a supersonic sawtooth nozzle for generating vacuum and a sawtooth jet type evacuator thereof.

The invention further relates to an ejector vacuum pump for generating a vacuum.

The invention further relates to an injector or an injection pump for delivering a fluid.

Background

The evacuator is characterized in that a fluid medium (called a main flow) with certain pressure and temperature enters a mixing diffusion chamber after being decompressed and accelerated by a Laval nozzle, is subjected to energy exchange and mixing with a pumped fluid (called a secondary flow) in the mixing diffusion chamber, carries the pumped fluid to be decelerated, mixed and pressurized in the mixing diffusion chamber, and finally overcomes outlet back pressure to be discharged, so that the purpose of pumping or conveying the secondary flow is achieved. In actual production, the main stream medium is usually water vapor, so the main stream medium is often called a water vapor evacuator, a water vapor ejector and a water vapor jet vacuum pump in engineering.

The air pump has the characteristics of simple structure, no moving part, stable and reliable work, simple installation, use and maintenance, large air pumping quantity and capability of pumping out a large amount of water vapor, dust, particles and other fluids, can provide a vacuum environment with the absolute pressure of not less than 1.33-0.13Pa for the process to the maximum extent, and is one of key equipment in the fields of petroleum, chemical industry, metallurgy, electric power, machinery, refrigeration, seawater desalination, pharmacy, military industry and the like. Although the structure of the evacuator is simple, the flow field mechanism in the evacuator is complex, and the air extraction theory, the design method and the like are not perfect.

The Laval nozzle structure used by the existing water vapor evacuator has the advantages of small evacuating capacity, large steam consumption, low efficiency and large noise, and is one of the large energy consuming households of a production device. The working efficiency of the evacuator depends mainly on two aspects: firstly, the most important is the structural form of the nozzle which completes energy conversion and generates vacuum; and the second is the flow passage form of the evacuator matched with the nozzle.

In the prior art, patent publication No. CN201949953U discloses an energy-efficient nozzle and a steam jet pump equipped with the same, which strives to achieve the goal of reducing steam consumption by using a straight nozzle tube section.

In the prior art, patent publication No. CN2475476Y discloses an ejector nozzle that achieves the goal of reducing steam consumption by employing a variable nozzle throat cross-sectional area. The steam consumption is large when the diameter of the throat part of the nozzle is large, and the steam consumption is small when the diameter of the throat part of the nozzle is small, however, the structural form is only convenient for adjusting the load, and the injection coefficient and the evacuation efficiency of the steam ejector are not researched and improved.

Disclosure of Invention

The invention mainly aims to greatly improve the injection coefficient and the working efficiency of an evacuator from the aspects of mechanism and effect, and discloses a supersonic sawtooth nozzle and a sawtooth jet type evacuator device thereof, which replace the largely used Laval nozzle evacuator at present, improve the flow and the distribution form of a mainstream fluid ejection nozzle from the aspect of mechanism and the flow and the distribution form of the pumped fluid in a mixed diffusion chamber, greatly reduce the consumption of the mainstream fluid of the evacuator, and reduce the pneumatic noise.

It is yet another object of the present invention to provide a jet vacuum pump for generating a vacuum in cooperation with a supersonic wave serrated nozzle.

It is yet another object of the present invention to provide an injector or jet pump for delivering fluids that is compatible with supersonic serrated nozzles.

According to the embodiment of the invention, the supersonic sawtooth nozzle with the fluid working medium comprises 3 parts: 1) a nozzle inlet section (symbol 1 in fig. 1); 2) a nozzle throat (symbol 2 in fig. 1); 3) nozzle outlet section (symbol 3 in fig. 1). These 3 parts are connected in sequence to form a complete zigzag nozzle structure.

The cross section area of the inlet section of the sawtooth nozzle is gradually reduced along the flowing direction, and the wall molded line of the sawtooth nozzle is a conical tube structure or an ideal Witoshiba molded line bus-axis symmetric convergence structure or an arc line, hyperbolic line or parabolic molded line structure taking the Witoshiba molded line as a prototype. The throat part of the nozzle is a circular channel with equal diameter. The nozzle outlet section is a Laval nozzle expansion section with a sawtooth modification at the tail edge (symbol 4 in figure 1) or a concave fan modification (symbol 4 in figure 2).

The tail edge sawtooth modification (symbol 4 in figure 1) is that a plurality of triangles are cut off on the profile of the tail edge of the expansion section of the Laval nozzle at equal intervals or unequal intervals along the circumferential direction, and the shape, the angle and the size of each triangle can be selected at will.

The tail edge concave sector modification (symbol 4 in fig. 2) is that a plurality of concave sectors are cut off on the molded surface of the tail edge of the expansion section of the laval nozzle at equal intervals or unequal intervals along the circumferential direction, and the shape of each concave sector is as follows: circular, elliptical, hyperbolic, parabolic, trigonal function, and the like, and any combination thereof, and any size.

A supersonic saw tooth nozzle evacuator apparatus mounted with [009] to [015], said saw tooth jet evacuator apparatus comprising: 1) an inlet section (symbol 5 in fig. 3) of the main flow fluid conduit; 2) a zigzag nozzle (symbol 6 in fig. 3); 3) a suction chamber (reference numeral 7 in fig. 3) and a secondary flow inlet section (reference numeral 13 in fig. 3) connected to the suction chamber; 4) mixing section of a mixing diffusion chamber (symbol 8 in fig. 3), which consists of two parts: the inlet part (symbol 9 in fig. 3) of the mixing section of the mixing diffusion chamber, and the convergent part (symbol 10 in fig. 3) of the mixing section of the mixing diffusion chamber; 5) a mixing diffuser throat (11 in fig. 3); 6) the diffuser section of the mixing diffuser chamber (symbol 12 in fig. 3). The supersonic sawtooth nozzle (symbol 6 in figure 3) is installed in the suction chamber, and the joints of the inlet section (symbol 1 in figures 1 and 2) of the sawtooth nozzle and the inlet section (symbol 5 in figure 3) of the main flow fluid pipeline are connected in a welding mode, or a gasket sealing and threaded connection mode, or a gasket sealing and flange connection mode.

An evacuator apparatus equipped with the supersonic serrated nozzle [009] to [015], wherein the outlet section of the supersonic serrated nozzle (6 in fig. 3) is a laval nozzle expansion section having a trailing edge serrated profile (4 in fig. 1) or a concave fan profile (4 in fig. 2).

Compared with the prior art, the invention has the beneficial effects that: the main flow is gradually accelerated in the inlet section of the sawtooth nozzle; the nozzle throat just reaches a critical state, and the speed is the local sound speed; in the nozzle outlet section, the supersonic fluid continues to expand and accelerate. At the end section of the nozzle outlet section, the velocity reaches a maximum and the pressure reaches a minimum, thus forming a low pressure zone. Because the secondary fluid pressure is higher than the low-pressure zone pressure, the secondary fluid is drawn into the evacuator under the influence of the pressure differential. Meanwhile, due to the viscous action of the fluid and the trailing edge shape modification structure of the sawtooth nozzle, compared with the existing Laval nozzle, the downstream main flow of the sawtooth nozzle is in contact with the secondary flow in advance, and the effective contact area is greatly increased, namely the acting force of the viscous drag of the main flow to the secondary flow is greatly improved. In addition, the tail edge of the outlet section of the supersonic sawtooth nozzle is modified, the flow form and streamline distribution of the main flow fluid after leaving the nozzle are changed, and the flow form of the main flow fluid and the injected secondary flow medium in the mixing diffusion chamber is improved. Finally, the ejection coefficient and the working efficiency of the sawtooth jet type evacuator are greatly improved in mechanism, so that the supersonic sawtooth jet type evacuator can greatly increase the ejected sub-flow mass flow under the same main flow fluid mass flow, or greatly reduce the main flow fluid consumption under the same ejected sub-flow mass flow, namely, the sawtooth jet type evacuator has high ejection coefficient and working efficiency essentially.

Drawings

FIG. 1 represents a basic schematic of a front view of a supersonic serrated nozzle of the embodiment of the present invention. In fig. 1, symbol 1 denotes a nozzle inlet section, symbol 2 denotes a nozzle throat in fig. 1, symbol 3 denotes a nozzle outlet section in fig. 1, and symbol 4 denotes a cut-away triangular portion in the nozzle outlet section in fig. 1.

FIG. 2 represents a basic schematic of a front view of a second supersonic wave serrated nozzle of the embodiment of the present invention. Wherein symbol 1 in fig. 2 denotes a nozzle inlet section, symbol 2 in fig. 2 denotes a nozzle throat, symbol 3 in fig. 2 denotes a nozzle outlet section, and symbol 4 in fig. 2 denotes a concave sector portion cut out in the nozzle outlet section.

Fig. 3 represents a basic schematic diagram of a saw tooth jet evacuator equipped with a supersonic saw tooth nozzle according to the embodiment of the present invention. Wherein, symbol 5 in fig. 3 represents a main flow fluid pipe inlet section, symbol 6 in fig. 3 represents a zigzag nozzle, symbol 7 in fig. 3 represents a suction chamber, symbol 8 in fig. 3 represents a mixing diffuser chamber mixing section, symbol 9 in fig. 3 represents a mixing diffuser chamber mixing section inlet portion, symbol 10 in fig. 3 represents a mixing diffuser chamber mixing section converging portion, symbol 11 in fig. 3 represents a mixing diffuser chamber throat portion, symbol 12 in fig. 3 represents a mixing diffuser chamber diffuser section, and symbol 13 in fig. 3 represents a secondary inflow port connected to the suction chamber.

Detailed Description

3 sections of the zigzag nozzle in fig. 1 or fig. 2: the nozzle inlet section (symbol 1 in figures 1 and 2), the nozzle throat (symbol 2 in figures 1 and 2) and the nozzle outlet section (symbol 3 in figures 1 and 2) are connected in sequence to form a complete supersonic sawtooth nozzle structure. Then, a complete supersonic sawtooth nozzle (symbol 6 in fig. 3) is installed in the suction chamber (symbol 7 in fig. 3), and the joint of the inlet section (symbol 1 in fig. 1 and 2) of the sawtooth nozzle and the inlet section (symbol 5 in fig. 3) of the pipeline of the mainstream fluid (such as steam, air and process fluid) is welded, or is in gasket sealing and threaded connection, or is in gasket sealing and flange connection; welding, or sealing and screwing a gasket or sealing and flange a process pipeline needing pumped fluid in a process device to a secondary inflow port (symbol 13 in figure 3); the outlet (symbol 12 in fig. 3) of the diffusion section of the mixing diffusion chamber is welded with a process pipeline for conveying mixed fluid in a process device, or is in gasket sealing and threaded connection, or is in gasket sealing and flange connection.

Finally, it is to be noted that: although the present invention has been described in detail with reference to examples, it will be apparent to those skilled in the art that various modifications, variations or equivalent arrangements may be made without departing from the spirit and scope of the present invention.

Claims

1. A supersonic sawtooth nozzle for evacuation comprising 3 sections: the nozzle comprises a nozzle inlet section, a nozzle throat and a nozzle outlet section, wherein the 3 parts are sequentially connected to form a complete supersonic sawtooth nozzle structure, and the supersonic sawtooth nozzle is characterized in that the cross sectional area of the nozzle inlet section is gradually reduced along the flow direction, the wall molded line of the nozzle inlet section is an ideal Wittonsissius molded line axisymmetric convergence structure, the nozzle throat is a circular channel with the same diameter, and the molded surface of the tail edge of the nozzle outlet section is a Laval nozzle expansion section with the shape modified by sawtooth at the tail edge or modified by a concave fan, so that the flow form and streamline distribution of the main flow leaving the nozzle are changed, and the flow form of the main flow and the injected secondary flow medium in a mixing diffusion chamber is improved.

2. The supersonic sawtooth nozzle of claim 1, wherein a plurality of triangles are cut from the profile of the trailing edge of the diverging section of the laval nozzle at equal or unequal intervals in the circumferential direction, the triangles having arbitrary shape angles and sizes.

3. The supersonic sawtooth nozzle of claim 1 wherein a plurality of concave sectors are cut circumferentially at equal or unequal intervals in the profile of the trailing edge of the diverging section of the laval nozzle, the concave sectors being shaped as: circular, elliptical, hyperbolic, parabolic, trigonometric, asymptotic and any combination thereof, the size of the concave sector being any.

4. A saw tooth jet evacuator apparatus with a supersonic saw tooth nozzle according to any of claims 1 to 3, characterized by: 1) a main flow fluid conduit inlet section; 2) a supersonic wave serrated nozzle; 3) a suction chamber and a secondary inlet connected to the suction chamber; 4) a mixing diffusion chamber.

5. The apparatus of claim 4, wherein the mixing plenum is formed by: 1) a mixing section; 2) a throat; 3) the diffusion section consists of 3 parts.

6. The apparatus of claim 4, wherein: the supersonic sawtooth nozzle is installed in the suction chamber, the cross section of the nozzle outlet is parallel or not parallel to the cross section of the mixing section inlet of the mixing diffusion chamber, the design principle is that the flow fields of the nozzle outlet and the mixing section inlet are matched, the sawtooth jet type evacuator adopts CFD design, the flow field of the mixing diffusion chamber is matched with the flow field of the supersonic sawtooth nozzle, and the maximum jet flow rate ratio and the optimal flow loss are achieved.