RU2243036C1 - Method to form a gas-drop jet and a device for its realization - Google Patents

Abstract

FIELD: fire-prevention engineering and agriculture; methods of production of gas-drop highly concentrated jets with a long range of action.

SUBSTANCE: the invention. The offered invention is dealt with technologies of production of highly concentrated jets having a long range of action and finely dispersive structure of drops. Such jets may be used in fire-prevention engineering and agriculture for sprinkling and in fields of economy, where there is a necessity in the finely dispersed long range gas-drop jets. The offered group of inventions solves the following problems: provision of formation of a gas-drops two-phase stream by a method permitting to increase an overall performance of the device due to more rationalized use of energy of a liquid and a guaranteed method of dispersion of a two-phase bubbling gas-liquid stream. This technical purpose in the offered invention is achieved by development of a method of formation of a gas-drop jet providing for feeding of a liquid and a gas stream, dispersion of the liquid, mixing of the dispersed liquid with the gas stream and a speed-up of the produced two-phase gas-drop jet, in which according to the invention, a liquid is fed along the axis of the gas-drop jet. At that the liquid is dispersed a stage by stage and a gas stream, and a liquid disperse stage by a stage, preliminary they create a two-phase stream of a bubbling structure by feeding a part of the gas in the liquid. Then this mixture is subjected to action of cavitation or shockwaves and then the dispersed liquid is mixed with the rest of the gas. The invention is also characterized by the fact, that the gas-drop jet is placed in an additional external gas coaxial stream of the same direction.

EFFECT: the invention ensures provision of formation of a gas-drops two-phase stream by a method permitting to increase an overall performance of the device.

4 cl, 2 dwg

Description

The present invention relates to a technology for producing highly concentrated jets having a long range and a finely divided droplet composition. Such jets can be used in fire fighting equipment, agriculture for irrigation and other industries where fine and long-range gas-droplet jets are needed.

Known methods for creating liquid jets, some of which provide range by increasing the pressure in the fluid supply system, and others by supplying a gas stream to the nozzle of the installation.

A known method of creating a gas-droplet jet, including the use of the ejecting action of a gas jet supplied to the gas nozzle nozzle, to disperse the fluid and increase the flight range of the jet (AS USSR No. 380279, class A 01 G 25/00, 1973).

The closest in technical essence to the proposed technical solution is a method of creating a gas-droplet jet, including the supply of a liquid and a gas stream, dispersing a liquid, mixing the dispersed liquid with a gas stream and accelerating the obtained two-phase gas-droplet stream (RF Patent No. 2107554, class A 62 C 31 / 02, 1998).

The disadvantage of this method is the limited nature of the used ways of forming a two-phase flow, reducing the efficiency of the gas-droplet jet, in particular the loss of kinetic energy of a liquid during the formation of a dispersed stream of a gas-droplet structure.

A device is known - a liquid atomizer, including a liquid supply system, which consists of an inlet section in the form of a conical confuser, a cylindrical section and an outlet section in the form of a conical diffuser sequentially conjugated and aligned with each other (see RF Patent No. 2184619, class B 05 V 1 / 00, 2001).

A disadvantage of the known design is the dependence of its operation on the flow parameters that determine the occurrence of the cavitation mode, which ensures crushing of the liquid and obtaining a gas-droplet flow.

The closest in technical essence to the proposed design is a device for creating a gas-droplet jet, including a chamber for forming a two-phase gas-droplet stream with inlets for supplying liquid and gas and a gas-dynamic nozzle associated with it (RF Patent No. 2107554, class A 62 C 31/02, 1998 )

The disadvantages of this method are the loss of kinetic energy of a liquid or its large costs for the formation of a gas-droplet stream.

The problem solved by the proposed group of inventions is to ensure the formation of a gas-droplet two-phase flow in a way that allows to increase the efficiency of the device due to a more rational use of liquid energy and a guaranteed method of dispersing a two-phase bubble gas-liquid flow.

The technical result in the present invention is achieved by creating a method of creating a gas-droplet jet comprising supplying a liquid and a gas stream, dispersing a liquid, mixing the dispersed liquid with a gas stream and accelerating the obtained two-phase gas-droplet stream, in which according to the invention the liquid is fed along the axis of the gas-droplet jet, the liquid being dispersed in stages pre-create a two-phase flow of the bubble structure by supplying part of the gas to the liquid, and then expose this cm when exposed to cavitation or shock waves, and then the dispersed liquid is mixed with the rest of the gas.

The invention is also characterized in that the gas-droplet stream is placed in an additional external gas coaxial stream in the same direction.

This allows you to increase the range of the created gas-droplet jet.

The invention is characterized by the fact that a device for creating a gas-droplet jet is developed, comprising a two-phase gas-droplet flow formation chamber with inlets for supplying liquid and gas and a gas-dynamic nozzle associated with it, which according to the invention is provided with a two-phase flow bubble formation chamber, which is installed in a two-phase gas-droplet formation chamber flow connected to the inlet of the fluid supply and has a gas supply inlet.

The supply of an external coaxial nozzle having a gas supply inlet and in which a gas-dynamic nozzle is located coaxially with it allows increasing the range of the created gas-droplet jet.

Using the proposed group of inventions makes it possible to more effectively use the energy of a liquid, converting it to the maximum extent into kinetic energy directed along the axis of the gas-droplet jet.

The resulting dispersed stream of droplets is smaller than in known methods. This makes it possible to obtain a higher liquid velocity at the outlet of the gas-droplet nozzle and, therefore, a greater jet range, all other things being equal, and an improvement in the quenching properties of the jet, since smaller droplets evaporate faster.

All of the above allows us to conclude: the proposed invention increases the efficiency of a gas-droplet jet.

The conducted patent studies showed that technical solutions with the indicated set of essential features are not known in similar methods for creating a gas-droplet jet and devices for their implementation, i.e. the group of proposed solutions meets the criterion of “novelty”.

In the analysis of known analogues and prototype, no proposal was found with a combination of essential features set forth in the claims, which implies that for specialists involved in methods for creating a gas-droplet jet and devices for their implementation, they do not explicitly follow from the prior art and, therefore, meet the criteria of the invention “inventive step”.

We believe that the information set forth in the application materials is sufficient for the practical implementation of the group of inventions.

The proposed group of inventions is illustrated by the following description and drawings, in which:

figure 1 shows a diagram of a device for implementing the method of creating a gas-droplet jet;

figure 2 shows a diagram of a device for implementing the method of creating a gas-droplet jet with an additional nozzle.

A device for creating a gas-droplet jet includes a chamber 1 for generating a two-phase gas-droplet flow with inlets for supplying a liquid 2 and gas 3, a gas-dynamic nozzle 4 connected to it, a chamber for generating a two-phase flow of a bubble structure, which is installed in a chamber 1 for generating a two-phase gas-droplet flow, connected to the feed inlet liquid 2 and has a gas inlet 5.

The inputs of the fluid and gas are connected to the nodes of the fluid supply 6 and gas 7.

The chamber for forming a two-phase flow of a bubble structure is made with a central channel consisting of a cylindrical section 8 and a conical section 9 connected in series, for example a nozzle (or diffuser). In this case, the cylindrical section of the chamber is connected to the inlet of the liquid supply 2 by means of a nozzle for the liquid 10. The nozzle 9 (or diffuser) is intended for acceleration or deceleration of the bubble stream.

The chamber 1 for generating a two-phase gas-droplet flow, the chamber for forming a two-phase flow of a bubble structure and the gas-dynamic nozzle 4 are so arranged relative to each other that they form a mixing chamber 11 for forming a gas-droplet flow of a dispersed structure.

Gas-dynamic nozzle 4 is designed to accelerate a gas-droplet flow of a dispersed structure and to obtain a gas-droplet jet. It can be made as a conventional nozzle, or annular with a central body for compacting the jet.

The proposed device can also be equipped with an external coaxial nozzle 12 having a gas inlet 13 and in which a gas-dynamic nozzle 4 is located coaxially with it.

Consider how the proposed method for creating a gas-droplet jet can be implemented.

The working fluid (gas) is divided into two streams: part of the gas stream is directed to the formation of a two-phase stream of a bubble structure, the second is used in a gas-droplet nozzle 4 to disperse a two-phase stream of a dispersed (gas-droplet) structure.

A two-phase flow of a bubble structure is obtained by mixing part of the gas into a liquid. This can be done at different stages of the method: either in the nozzle 10 for supplying liquid, or after its preliminary acceleration to reduce the pressure in the chamber for the formation of a two-phase flow of a bubble structure.

The obtained two-phase stream of the bubble structure created by mixing the liquid and part of the gas stream is either slowed down to a speed providing a pressure equal to the pressure in the mixing chamber 11, or accelerated to a speed exceeding the speed of sound in the two-phase stream.

For this purpose, to disperse the fluid, you can use the nozzle 10 for supplying fluid, to mix and obtain a bubble stream - a chamber for the formation of a two-phase stream of a bubble structure, to disperse a bubble stream - nozzle 9. This nozzle can play the role of a diffuser when braking the bubble stream.

After the process of acceleration or deceleration of the bubble stream, it is sent to the mixing chamber 11, where the remaining gas stream is simultaneously supplied.

The gas flow rate G _G1 to obtain the flow of the bubble structure is selected from the condition G _G1 <G _W P / RTρ _W , where

G _W - mass flow rate of liquid,

G _G1 - mass flow rate of gas mixed with the liquid to obtain a bubble stream,

P is the pressure in the region where a part of the gas is supplied to the liquid during the formation of a bubble structure stream;

R is the gas constant gas flow

T is the temperature of the gas-liquid mixture of the bubble stream,

ρ _W - the density of the liquid.

The liquid may be water, oil, etc.

The bubble stream in the nozzle 9 (or diffuser) is destroyed under the influence of either cavitation or shock waves, forming a gas-droplet mixture at the outlet, which is sent to the mixing chamber 11, where it is further intensively destroyed, depending on the values of the parameters i.e. the transition from the bubble structure to dispersed with the formation of small drops.

At the same time, the remaining gas stream enters this mixing chamber 11, which is mixed with the dispersed liquid stream, forming a gas-droplet mixture.

The gas-droplet mixture thus obtained is directed to a gas-droplet nozzle 4, in which it is accelerated to a predetermined speed and a concentrated gas-droplet jet with fine droplets is formed at the outlet of the nozzle 4.

Then, to increase the distribution range of the previously created jet, the gas-droplet jet is placed in an additional external gas coaxial stream of the same direction, which is created in the additional nozzle 12.

To do this, the gas inlet 13 is connected either to the gas supply unit 5, or to an independent power source (not shown). The gas jacket of the gas jet 15 surrounding the stream 14 provides at a certain distance, at least, the absence of braking of the gas-droplet stream. This distance is determined by the range of the gas stream.

A turbocompressor unit may be used as a gas source.

The turbocharger installation can be equipped with a pump to provide the necessary fluid parameters.

If necessary, the installation can be performed mobile; for this, it is equipped with a vehicle, for example, automobile, helicopter, airplane, sea.

The parameters of the device for implementing the proposed method, such as pressure P _to in the mixing chamber 11, mass second flow rates of liquid G _g and gas G _g , initial fluid pressure P _g , are selected from the conditions for obtaining a given jet propagation length.

As calculations show, the proposed method for producing a gas-droplet flow in the mixing chamber and reducing the dispersion of droplets allows increasing the speed of liquid droplets in the jet and increasing the efficiency of the jet, all other things being equal.

The work of the proposed group of inventions is as follows.

The device is moved to its original position, for example, using a conveyance means (not shown). The nozzle 4 with the flow of the gas-droplet structure is directed towards the object to which the gas-droplet jet is to be supplied.

The fluid in the device is produced through the node 6 of the fluid supply.

In this case, the supply of one part of the gas through the node 7 and the inlet 5 is carried out in the chamber for forming a two-phase stream of the bubble structure to obtain a bubble stream and the remaining part of the gas through the node 7 in the mixing chamber 11.

The bubble stream is accelerated in the nozzle 9 to supersonic speeds in terms of sound speed in a two-phase medium, or slowed down to a speed that ensures that at the exit of the nozzle 9 (diffuser) with a bubble structure of pressure equal to the pressure in the mixing chamber 11, and then sent to the mixing chamber 11 where the further formation of the structure of the gas-droplet flow occurs, crushing of the liquid and the formation of a finely dispersed gas-droplet flow.

The other part of the gas stream, through node 7 also entering the second mixing chamber 11, is mixed with drops to form a dispersed gas-and-droplet stream, which enters the gas-droplet nozzle 4, and there it is accelerated to a predetermined speed, creating a finely dispersed highly concentrated gas-droplet jet.

Tests were carried out with the following parameters:

P _to = 5 × 10 ⁵ PA - pressure in the mixing chamber;

G _W = 0.4 kg / s is the mass flow rate of the liquid;

G _G1 = 0.01 kg / s - mass gas flow;

G _G1 = 0.0024 kg / s - the mass flow rate of a part of the gas used to create a two-phase bubble flow;

P _W = 10 × 10 ⁵ Pa - fluid pressure.

The propagation range L _{gas of a} gas stream is of the order of 100 calibers of the initial diameter D _{gas of a} gas stream, i.e. L _gas / D _gas = 100.

The range of the gas-droplet jet L of the _gas-cap is about 1000 of the initial diameter d of the _gas-cap , i.e. L _{gas cap} / D _{gas cap} = 1000.

If we assume that D _gas / d _{gas cap} = 10, then L _gas = 1000 d _{gas cap} , i.e. over a length of 1000 d gas- _cap gas jet will protect the gas-droplet jet and, thus, can double the spread of the gas-droplet jet.

The results obtained on the propagation of a gas-droplet jet indicate that the parameters selected in accordance with the above conditions and the organization of the process for producing a jet in accordance with the proposed method can improve the efficiency of the obtained two-phase gas-droplet jet due to a more complete use of the energy of the liquid and an improvement in its dispersion process.

In particular, the range of the jet increased by 1.5 times compared with the prototype under the same boundary conditions.

With an initial diameter of a gas-droplet jet obtained by the proposed method of about 10 mm, the range of such a jet is 10 m (1000 calibers of the initial diameter).

In tests conducted using a satellite gas stream of the same direction with a diameter of 100 mm, the range of a gas-droplet jet increases to 20 m.

The presented information confirms the feasibility of the proposed method for creating a gas-droplet jet, as well as the device with which the method is implemented, and the possibility of achieving a technical result, which consists in increasing the efficiency of a gas-droplet jet.

The most effective use of the invention in fire fighting equipment for extinguishing fires in facilities where it is necessary to use the minimum amount of liquid with maximum efficiency (reducing damage from the extinguishing process itself), in climate systems for agriculture, medicine, ecology, etc.

Claims (4)

1. A method of creating a gas-droplet jet, comprising supplying a liquid and a gas stream, dispersing a liquid, mixing the dispersed liquid with a gas stream and accelerating the obtained two-phase gas-droplet stream, characterized in that the liquid is supplied along the axis of the gas-droplet jet, the liquid being dispersed in stages, a two-phase flow is preliminarily created bubble structure by feeding part of the gas to a liquid, and then exposing this mixture to cavitation or shock waves, and then the dispersed liquid see Shiva with the remainder of the gas. 2. The method of creating a gas-droplet jet according to claim 1, characterized in that the gas-droplet jet is placed in an additional external gas coaxial stream of the same direction. 3. A device for creating a gas-droplet jet, comprising a chamber for forming a two-phase gas-droplet stream with inlets for supplying liquid and gas and a gas-dynamic nozzle associated with it, characterized in that it is provided with a chamber for forming a two-phase flow of a bubble structure, which is installed in the chamber for forming a two-phase gas-droplet stream, connected to the fluid inlet and has a gas inlet. 4. A device for creating a gas-droplet jet according to claim 3, characterized in that it is equipped with an external coaxial nozzle having a gas inlet and in which a gas-dynamic nozzle is located coaxially with it.

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