RU176037U1 - DEVICE FOR SPRAYING A LIQUID IN A GAS MEDIUM WITH FORMATION OF A TWO-PHASE JET WITH A HIGH SPEED AND DISPERSION OF A LIQUID - Google Patents

Abstract

The present device relates to techniques for spraying liquids in a gaseous medium, preferably in air, and can be used to spray a significant amount of liquid in a short period of time with the formation of a two-phase flow with high speed and dispersion of the liquid or high-speed foam flow, in particular for fire fighting purposes. The device contains a chamber for mixing gas and liquid, which enter the mixing chamber under excessive pressure from sources of liquid and gas, while gas is introduced through several holes into the mixing chamber, which is located at the beginning of the line through which the gas-liquid mixture flows to the spray nozzle or nozzles. The device may include nodes for adjusting the liquid and / or gas flow located in front of the entrance of the flows into the mixing chamber. The mixing chamber can be made in the form of a hydro-jet pump, consisting of a series-connected confuser and a diffuser so that gas is introduced into the fluid stream in the region of their connection. The mixing chamber may be provided with several identical openings through which gas is introduced into the fluid flow, the number and smallest diameter of the openings affect the speed and dispersion of the sprayed fluid flow; and in the case of foam generation, including, determine its multiplicity and the average equivalent diameter of the bubbles in it. The smallest diameter of the holes for introducing gas into the fluid stream can be made equal to the average equivalent diameter of the bubbles in the finished, i.e. expanded foam. The holes in the mixing chamber can be made in the form of a confuser. The holes in the mixing chamber can be made oblique or coaxial in the direction of fluid flow. The gas-liquid line can be equipped with a stabilizer for the plug flow of a two-phase mixture. The spray nozzle may be provided with an outlet gas-liquid nozzle formed by an inlet confuser, a cylindrical section and an outlet diffuser. The technical result is achieved by simplifying the design and increasing the efficiency of the device. 8 s.p. f-ly, 6 ill.

Description

The present device relates to a technique for spraying liquids in a gaseous medium, preferably in air, and can be used to spray a significant amount of liquid in a short period of time with the formation of a two-phase flow with high speed and dispersion of the liquid or high-speed foam flow, in particular for fire fighting purposes (in further device). The device can be used as a primary (fire extinguisher) or be part of a mobile fire extinguishing medium (for the definition of the scope and types of fire fighting equipment, see No. 123-FZ “Technical Regulations on Fire Safety Requirements”, chapter 12. Classification of fire fighting equipment).

Fire extinguishing devices with a reservoir for a fire extinguishing liquid (OTF, mainly water and water with additives) are known in the prior art, in which overpressure is generated by the displacing gas. When the shut-off valve is opened, the coolant through the sprayer is thrown into the combustion zone with the possible formation of air-mechanical foam and provides fire fighting.

Liquid ejection through the atomizer at a relatively low pressure of displacing gas not exceeding 2.5 MPa for fire extinguishers with liquid extinguishing agents (GOST R 51057-2001. Fire fighting equipment. Portable fire extinguishers. General technical requirements. Test methods), does not provide high speed, range and the dispersion of a jet of liquid or foam, which is necessary for effective fire fighting; in addition, the jet of electrically conductive fluid obtained in this way does not allow to extinguish electrical installations under voltage.

The most common types of commercially available mobile fire extinguishing means are the main fire engines designed to extinguish fires with the help of OTF exported to them, as well as to supply OTG from other sources to the fire site. All major general-purpose fire engines are equipped with fire pumps, OTZ storage tanks and means for their supply (GOST R 53247-2009 “Fire-fighting equipment. Fire engines. Classification, types and designations”). Most of the main fire engines of general use are equipped with normal pressure pumps, the generated pressure of which is not higher than 1 MPa (Bezborodko M.D. Firefighting equipment. - M .: Academy of the State Fire Service of the Ministry of Emergencies of Russia, 2004, p. 59-75). The specified pressure does not provide high speed and dispersion of the jet of liquid or foam, which are necessary for effective fire fighting; in addition, the jet of water or foam obtained in this way does not allow to extinguish electrical installations under voltage.

To overcome these drawbacks, the coolant can be mixed with gas before being fed into the combustion zone, as a result of which a two-phase flow is formed, which provides an increase in the speed and dispersion of the resulting coolant jet. Below are examples of the implementation of such devices.

Known automatic (RU 2536224) and modular (RU 2460561) fire extinguishing systems related to stationary technical means of extinguishing a fire (for definition of the scope and types of fire fighting equipment, see No. 123-FZ "Technical regulation on fire safety requirements", chapter 12. Fire classification techniques), which contain a chamber for mixing gas and liquid, sources of gas and liquid, while the mixing chamber is located at the beginning of the pipeline through which the gas-liquid mixture flows to the spray nozzles.

However, the devices according to the patents RU 2536224 and RU 2460561 cannot be used as the primary (fire extinguisher) or mobile fire extinguishing means since the described devices are stationary and exclude operator’s participation in delivering the device to the fire and jet control (direction, emission intensity, etc.). In addition to the above drawback, these devices do not provide the formation of monodisperse foam, so the gas enters the mixing chamber through a single hole.

Known water-jet pumps, in particular intended for mixing a liquid stream with a stream of sucked-in gas and their subsequent joint transportation (Lyamaev B.F. Water-jet pumps and installations. - L .: Mashinostroyeniye, 1988. - 256 p.). The gas suction effect occurs as a result of a decrease in pressure in the accelerated fluid flow. At the same time, the fluid accelerates as the tapering confuser passes, and the gas is supplied to the portion of the fluid flow that has the highest velocity, i.e. between the confuser and the diffuser.

Known gas-liquid nozzle formed by the inlet confuser, the cylindrical section and the outlet diffuser (RU 2317837). The gas-liquid nozzle allows you to effectively convert the excess pressure of the two-phase gas-liquid mixture into the kinetic energy of the resulting two-phase flow.

A device for producing a gas-droplet jet (RU 2283152, prototype) is known, comprising an exhaust gas-liquid nozzle connected to a gas and liquid mixing chamber in such a way that the outlet of the mixing chamber coincides with the inlet of the exhaust gas-liquid nozzle, and the mixing chamber is connected by lines to liquid containers and compressed gas, while the output end of the gas line is made in the form of a gas-dynamic nozzle and the gas line is located coaxially inside the liquid line, and the outlet The outlet of the liquid manifold forms the inlet of the mixing chamber located coaxially with the outlet of the chamber and the gas-liquid nozzle, and a valve with a small dynamic resistance is installed between the inlet and outlet openings of the mixing chamber and provides simultaneous opening / closing of both the liquid and gas lines.

However, the device according to patent RU 2283152 has the following disadvantages:

1. The insufficient velocity of the gas-droplet jet due to the inhibition of gas-liquid flow by a valve installed between the inlet and outlet openings of the mixing chamber.

2. The complexity of the design, low maneuverability and high weight of the device due to the complex design of the spray gun and the presence of two supply lines to it.

3. Significant pressure loss in the liquid line, if it is made long and is supplied to a considerable height.

4. The mixing chamber of the device does not allow the generation of monodisperse foam, since liquid and gas enter the mixing chamber through single annular and round openings, respectively.

To overcome these drawbacks of the known devices, it is proposed to introduce gas through several openings in the OZ stream before supplying the liquid coolant through the main line to the spray nozzle, which provides an increase in the speed and dispersion of the sprayed liquid flow, and in the case of obtaining foam allows the generation of monodisperse foam, which also increases multiplicity and stability; in addition, in the proposed device, the pressure loss in the gas-liquid line is reduced in comparison with the liquid line, especially if the line is long and fed to a considerable height.

The utility model is aimed at overcoming these drawbacks of known fire extinguishing devices using OTF, due to which a technical result is achieved, which consists in simplifying the design and increasing the efficiency of the devices.

The claimed technical result is achieved by the implementation of a set of features that make up the essence of the utility model.

The device contains a chamber for mixing gas and liquid, which enter the mixing chamber under excessive pressure from sources of liquid and gas, while gas is introduced through several holes into the mixing chamber, which is located at the beginning of the line through which the gas-liquid mixture flows to the spray nozzle or nozzles. The device may include nodes for adjusting the liquid and / or gas flow located in front of the entrance of the flows into the mixing chamber. The mixing chamber can be made in the form of a hydro-jet pump, consisting of a series-connected confuser and a diffuser so that gas is introduced into the fluid stream in the region of their connection. The mixing chamber can be equipped with several identical openings through which gas is introduced into the fluid flow, the number and smallest diameter of the openings affect the speed and dispersion of the sprayed fluid flow, and in the case of foam generation, including its multiplicity and the average equivalent diameter bubbles in it. The smallest diameter of the holes for introducing gas into the liquid stream in the mixing chamber can be made equal to the average equivalent diameter of the bubbles in the finished one, i.e. expanded foam. The holes in the mixing chamber can be made in the form of a confuser. The holes in the mixing chamber can be made oblique or coaxial in the direction of fluid flow. The gas-liquid line can be equipped with a stabilizer for the plug flow of a two-phase mixture. The spray nozzle may be provided with an outlet gas-liquid nozzle formed by an inlet confuser, a cylindrical section and an outlet diffuser.

Using the above set of features, the efficiency is increased, the scope of application is expanded, and the design of the device is simplified.

The utility model is illustrated by examples of specific performance of serial devices. The accompanying drawings show the following:

In FIG. 1 shows a diagram of the implementation of the device, which is part of a mobile fire extinguishing means, equipped with a pump for supplying OTF: firefighters of a car, ship, train, motor pump, etc .;

in FIG. 2 shows a diagram of the implementation of the device as a fire extinguishing device equipped with a container for OTF, which is under excess pressure: a fire extinguisher, a stationary fire extinguishing installation, etc., while the mixing chamber is placed outside the capacity for OTG;

in FIG. 3 shows a diagram of the implementation of the device as a fire extinguishing means, equipped with a tank for OTF under pressure: a fire extinguisher, a stationary fire extinguishing installation, etc., while the mixing chamber is placed inside the gas cavity of the tank for OTG;

in FIG. 4 shows a mixing chamber made in the form of a hydro-jet pump;

in FIG. 5 shows a mixing chamber of a simplified design;

in FIG. 6 shows an exhaust gas-liquid nozzle.

With reference to FIG. 1-6 are indicated:

1) a chamber for mixing liquid and gas;

2) a source of liquid - a pump, a container under pressure;

3) gas source - compressor, gas bottle;

4) the highway for the gas-liquid mixture is a fire hose;

5) spray nozzles - fire barrel;

6) fluid flow adjustment unit;

7) gas flow adjustment unit;

8) openings for introducing gas into the fluid stream;

9) the smallest diameter of the holes;

10) a stabilizer for the cork flow of a two-phase mixture;

11) an exhaust gas-liquid nozzle;

12) the confuser of the exhaust gas-liquid nozzle;

13) a cylindrical section of the exhaust gas-liquid nozzle;

14) a diffuser of the exhaust gas-liquid nozzle;

15) confuser mixing chamber;

16) diffuser mixing chamber;

17) openings for introducing gas into the fluid stream are made in the form of a confuser.

The device (Fig. 1, Fig. 2, Fig. 3) contains a chamber for mixing liquid and gas 1, into which liquid and gas come under excessive pressure from sources of liquid 2 and gas 3, while gas is introduced through several holes into the mixing chamber 1 , which is located at the beginning of the line 4, through which the gas-liquid mixture enters the spray nozzle 5. The device contains nodes for adjusting the liquid 6 and / or gas stream 7 located in front of the inlet flows into the mixing chamber 1.

The mixing chamber (Fig. 4, Fig. 5) is equipped with several identical openings 8 through which gas is introduced into the fluid stream. The smallest diameter 9 of the holes 8 for introducing gas into the liquid stream in the mixing chamber is made equal to the average equivalent diameter of the bubbles in the finished one, i.e. expanded foam. The number and smallest diameter of 9 holes 8 affect the flow rate, speed and dispersion of the flow of the sprayed liquid; and in the case of foam generation, including, determine its multiplicity and the average equivalent diameter of the bubbles in it.

In the gas-liquid line 4, in front of the spray nozzle 5, a plug-flow stabilizer for the two-phase mixture 10 is installed. The spray nozzle 5 is equipped with an exhaust gas-liquid nozzle 11 (Fig. 6) formed by the inlet confuser 12, the cylindrical section 13 and the outlet diffuser 14.

One embodiment of the mixing chamber is shown in FIG. four.

The mixing chamber (Fig. 4) is made in the form of a hydro-jet pump, consisting of a confuser 15 and a diffuser 16 connected in series so that gas is introduced into the liquid stream in the region of their connection. The holes 8 in the mixing chamber (Fig. 4) are made in the form of confusers 17, which are directed at an acute angle to the direction of fluid flow.

Other embodiments of the mixing chamber 7 are possible. Thus, for example, in FIG. 5 shows a mixing chamber of a simpler design and, accordingly, simpler to manufacture.

The device operates as follows. After opening the control nodes 6 and / or 7, the liquid and gas under excess pressure enter the mixing chamber from the sources of liquid 2 and gas 3. The liquid flows sequentially through the confuser 15 and the diffuser 16 of the mixing chamber 1 (Fig. 4). With the passage of fluid through the junction of the confuser 15 and the diffuser 16, it has a maximum speed, which provides a decrease in pressure in the fluid flow. The resulting pressure drop between the gas entering the mixing chamber and the liquid flow in the area between the confuser 15 and the diffuser 16 leads to effective penetration through the openings 8 and mixing of the gas with the liquid, and in the case of using a foaming solution, foam of the necessary multiplicity and dispersion is generated. The process of mixing gas with liquid and foam generation is facilitated by the implementation of holes 8 in the form of confusers 17, which are directed at an acute angle to the direction of fluid flow. The smallest diameter of 9 holes 8, equal to the average equivalent diameter of the bubbles in the finished, i.e. expanded foam, in the case of using a foaming agent solution provides the generation of foam of minimal polydispersity (monodisperse foam). As a result of the implementation of these processes, the flow in the line 4 below the holes 8 becomes two-phase, and in the case of using a foaming solution, monodisperse foam is generated. In the process of further movement of the two-phase flow sequentially through: line 4; cork flow stabilizer of a two-phase mixture 10; spray nozzles 5; input confuser 12; a cylindrical section 13 and an output diffuser 14 of the gas-liquid nozzle 11 (Fig. 6), a two-phase jet is formed with a high speed and dispersion of the liquid or high-speed foam flow.

Claims (9)

1. Fire extinguishing device, characterized in that it contains a mixing chamber of gas and liquid, which enter the mixing chamber under excessive pressure from sources of liquid and gas, while the gas is introduced through several holes into the mixing chamber, which is located at the beginning of the highway, along which the gas-liquid mixture enters the spray nozzle or nozzles. 2. The device according to p. 1, characterized in that it contains nodes for adjusting the liquid and / or gas flow located in front of the entrance of the flows into the mixing chamber. 3. The device according to any one of the preceding paragraphs, characterized in that the gas-liquid line is equipped with a stabilizer plug flow for a two-phase mixture. 4. The device according to p. 1, characterized in that the spray nozzle is equipped with an exhaust gas-liquid nozzle formed by an inlet confuser, a cylindrical section and an outlet diffuser. 5. The device according to claim 1, characterized in that the mixing chamber is made in the form of a hydro-jet pump, consisting of a confuser and a diffuser connected in series so that gas is introduced into the fluid stream in the region of their connection. 6. The device according to p. 1, characterized in that the mixing chamber is provided with several identical openings through which gas is introduced into the fluid flow, the number and smallest diameter of the openings affect the speed and dispersion of the sprayed fluid flow; and in the case of foam generation, including, determine its multiplicity and the average equivalent diameter of the bubbles in it. 7. The device according to claim 6, characterized in that the smallest diameter of the holes for introducing gas into the liquid stream in the mixing chamber is made equal to the average equivalent diameter of the bubbles in the finished one, i.e. expanded foam. 8. The device according to p. 6, characterized in that the holes in the mixing chamber are made in the form of a confuser. 9. The device according to p. 6, characterized in that the holes in the mixing chamber are made inclined or coaxial in the direction of fluid flow.

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