Two-phase mist jet nozzle

Abstract

The invention relates to a device for generating a two-phase fluid jet comprising a rotating nozzle. Said device comprises: a fixed base (10) having: a central connection (14) for connecting a first-phase inlet opening at the center of the inner surface of said fixed base, a peripheral connection (13) for connecting a second-phase inlet opening at the periphery, in an annular zone, of the inner surface of said fixed base; a fixed body (20), integral with said base, having a central conduit (34) for the passage of said first phase, surrounded by a coaxial annular chamber (46), for the passage of said second phase; a body (30) rotating about an axis corresponding to the longitudinal axis of said fixed body (21), having at least one rotating joint disposed in the interface with said fixed body; said rotating body (30) having a connection for receiving a two-phase diffusion nozzle (40).having a longitudinal axis (41) not aligned with the longitudinal axis (21) with said fixed body (20), a central conduit (100) for supplying the nozzle with said first phase, said orifice opening onto the upstream face of said body through an opening leading into said central conduit, and at least one peripheral conduit (102), communicating with said coaxial annular chamber, for the passage of said second phase, said body comprising a means for rotational drive relative to said fixed body. Figure of the abstract: Figure 1,

Description

Title of the invention: Two-phase mist jet nozzle

[0001] The present invention relates to the field of the production and propulsion of a two-phase mixture of at least one gas and one liquid, particularly for fire suppression, equipment cooling, and mist formation. The mixing takes place in a nozzle where the interaction of a high-speed gas stream with a water jet atomizes water droplets within the water jet to form a mist of very small or minute droplets, thus creating a two-phase mixture of water mist droplets carried along and transported by the gas stream. When the relative flow rate between the two fluids is high, the inertial forces exerted result in the formation of bubbles or droplets.

[0002] Such two-phase mixtures exhibit remarkable cooling performance and limit damage caused by water and fumes by producing low and localized wetting, with no surrounding nuisance. These mixtures are produced either by fixed installations located, for example, on the ceiling of an industrial, commercial or residential building, a tunnel, the fuselage of an aircraft or ship, or in the cockpit of an aircraft pilot or an industrial equipment operator, or in installations located on industrial sites or in forest areas, or by portable equipment in the form of fire hoses operated by a firefighter or by an autonomous motorized vehicle.

[0003] The finer the mist, the higher the droplet velocity, and the greater the droplet kinetic energy, the greater their ability to penetrate deeply into the fire. As the heat exchange surface area increases, so do the cooling and inert effects. The high-pressure water mist also blocks radiant heat. Thus, for example, the temperature can remain bearable just a few meters from a fire reaching 800°C, and it attenuates the shock waves caused, for example, by an explosion.

[0004] The gas supplying the nozzle can be an inert gas, such as nitrogen, carbon dioxide, argon, or simply air, or even oxygen. State of the art

[0005] French patent EP3037176B1 describes a nozzle-type device for spraying fluid, comprising a body with a supply inlet that receives the fluid supply and two or more spray holes that communicate with the supply inlet and are open on one fluid spray side. According to one of the described variants, the control element is a tubular rotating ring arranged around an external circumferential portion of the body in a rotational manner. Each rotating nozzle arranged in the body includes a projection that is positioned through the hole corresponding spray pattern and protrudes from the fluid spray side. Each rotary nozzle includes an annular groove on an external circumferential surface, and the annular groove receives a retaining pin projecting from a wall surface of the corresponding spray hole and extending into the corresponding spray hole. The retaining pin engages with the annular groove to retain the rotary nozzle in the body in a rotational manner. The rotation control mechanism, which rotates each rotary nozzle by rotating the rotary ring, is arranged between an internal circumferential surface of the rotary ring and the protrusion of each rotary nozzle facing the internal circumferential surface.

[0006] US patent 9352340B2 describes a device for ejecting at least a two-phase mixture, comprising at least one injection inlet (INI, IN2) for a liquid (11) and a gas (G1), a distribution chamber (EMD) for producing a first liquid-gas mixture (MLG1), and an ejection nozzle (EJ) for the first liquid-gas mixture along a principal direction defined by a vector axis. The ejection nozzle has a geometry with at least one minimum cross-section, called the throat, along its length at a location (X) on the vector axis.

[0007] The invention has an aspect coupling several nozzles as described above and arranged on a rotating support, allowing in addition to a gyratory action by the expansions of the nozzles and their particular arrangements on the rotor and between them, to sweep targeted surfaces in a complete and extensive way or to project jets of mist over a large volume without trying to precisely reach a flame zone for example.

[0008] French patent FR3037826B1 describes a spraying unit, for spraying a liquid onto vegetation, comprising a nozzle formed by a tube, a rotating atomizer and a fan generating a carrier airflow around the latter, a drive system, conveying means for conveying the liquid to said atomizer capable of fragmenting it into droplets.

[0009] International application WO00 / 12177 relates to a method for producing fire-extinguishing foam, comprising mixing and foaming water, a gas (e.g., air), and a fluid foam, the gas being added to the water under pressure before the gas-water mixture leaves the nozzle to disperse the foam. The nozzle head comprises a nozzle head insert that rotates under water pressure relative to an inlet sleeve, and at least one emission conduit in fluidic communication with the inlet sleeve via the nozzle head insert. Solution provided by the invention

[0010] The present invention aims to enable the production of spray nozzles per forming in particular for firefighting, allowing the diffusion of a two-phase fog.

[0011] To this end, the invention, in its most general sense, relates to a device for generating a two-phase fluid jet comprising a rotating nozzle, characterized in that it comprises: • a fixed base featuring: • a central connection for connecting a first-phase inlet emerging in the center of the inner surface of said fixed base, • a peripheral connection for connecting a second-phase supply emerging at the periphery, in an annular zone, of the inner surface of said fixed base • a fixed body, integral with said base comprising • a central conduit for the passage of said first phase, • surrounded by a coaxial annular chamber, for the passage of said second phase, • a body rotating about an axis corresponding to the longitudinal axis of said fixed body, having at least one rotating joint disposed in the interface with said fixed body • said body having a fitting to receive a two-phase diffusion nozzle, having a longitudinal axis not aligned with the longitudinal axis of said fixed body • a central conduit for supplying the nozzle with said first phase, said orifice opening onto the upstream face of said body through an opening leading into said central conduit • and at least one peripheral conduit, communicating with said coaxial annular chamber, for the passage of said second phase, • this body comprising a means of rotational drive relative to the fixed body.

[0012] Preferably, said first phase is pressurized air.

[0013] Preferably, said second phase is water.

[0014] According to a first embodiment, said drive means consists of a helical shape positioned in the peripheral conduit

[0015] According to a second embodiment, said drive means consists of an electric motor mechanically coupled to said rotating body.

[0016] According to a third embodiment, said drive means consists of a hydraulic motor mechanically coupled to said rotating body.

[0017] According to a fourth embodiment, said drive means consists of a magnetic ring fixed to said rotating body, interacting electro- genetically with a wound peripheral stator.

[0018] According to a fifth embodiment, said drive means is a pneumatic or hydraulic motor.

[0019] According to one embodiment, said rotating body comprises at least one nozzle having a main conduit supplied by a pressurized gaseous fluid and opening into a mixing chamber, as well as at least one secondary conduit supplied by at least one pressurized liquid fluid opening into said mixing chamber in a direction forming a non-zero angle with the axis of said main conduit.

[0020] Advantageously, said mixing chamber has a convergent-divergent cylindrical wall having a constriction defining an opening in the plane perpendicular to the axis of said main conduit, the convergent part of said wall having a frustoconical zone in the extension of the axis of said at least one secondary conduit, to form a fragmentation chamber of the liquid phase.

[0021] According to one variant, the axis of said at least one secondary conduit forms with the axis of said main conduit an angle between 2° and 20°.

[0022] According to another variant, the axes of the secondary conduits define with the generatrix of the cone of the converging part an angle between 0° and 60° and preferably of 45% ±10°.

[0023] Advantageously, the diameter of said opening of the constriction is between 0.8 and 1.2 times the diameter of said main conduit.

[0024] According to a particular embodiment, said nozzle(s) having a mixing chamber forming a so-called Laval nozzle.

[0025] Detailed description of non-limiting examples of embodiment

[0026] The present invention will be better understood upon reading the following description, referring to non-limiting examples of embodiment, illustrated by the accompanying drawings where: • [Fig. 1] [Fig. 1] represents a front view of a first example of an embodiment of a device according to the invention • [Fig.2] [Fig.2] represents a front view of a second example of a implementation of a device according to the invention • [Fig. 3] [Fig. 3] represents a cross-sectional view of a device according to the invention • [Fig. 4] [Fig. 4] represents a longitudinal cross-sectional view of a device according to the invention • [Fig.5] [Fig.5] represents a perspective view of a device according to the invention. General note

[0027] The description of one of these elements naturally extends to subsets including This element can be combined with another element, even if the first element is not described in detail in the section concerning the detailed description of that other element. Similarly, each element can be used with a complementary element other than the one described or even the subject of this patent: the nozzle that is the subject of the patent can be extended by a nozzle other than the one proposed by this patent, just as the described nozzle can be used with nozzles other than those covered by this patent. The same applies to all elements that are the subject of a detailed description.

[0028] Description of an example embodiment of the nozzle 1. Figure 1 shows a front view of a first variant embodiment, with a rotating nozzle (40). The device includes a base (10) supported by feet (11, 12) allowing it to be fixed to a plinth or a ceiling.

[0029] The fixed part, comprising the base (10) and the body (20), is cylindrical with a longitudinal axis (21). The rotating body (30) is extended by a nozzle (40) whose longitudinal axis (41) forms an angle of approximately 55° with respect to the longitudinal axis (21) of the fixed part. In the example described, it has a series of axial nozzles (31).

[0030] A rotating part disposed inside the fixed body (20) is provided with a toothed wheel (52) driven by the output pinion (51) of an electric, hydraulic, or pneumatic motor. The drive could, of course, also be achieved by a chain or belt system.

[0031] Fig. 2 represents an alternative with two rotating nozzles (40, 45), oriented along axes (41, 42) whose rotation defines a cone coaxial with the longitudinal axis (21). Description of operation

[0032] The base (10) has two threaded holes (13, 14) intended respectively for connecting a water supply and a pressurized air supply. The connections are shown on the front face, but one or both could also be provided radially.

[0033] The rotating body (30) is extended by a cylindrical rod having two coaxial conduits consisting of an annular longitudinal chamber (32) and a central conduit (34) delimited by a cylindrical partition (33). This central conduit (34) is intended for supplying the nozzle allowing the arrival of the first phase.

[0034] The annular longitudinal chamber (32) allows the circulation of the liquid phase which entered through (13) towards the annular distribution chamber.

[0035] The bore (13) for the water supply opens into an annular distribution chamber (36) formed by a flared section of the annular longitudinal chamber (32). The guidance of this fixed rod (31) relative to the rotating body (30) is ensured by a rear bearing (22) and a front bearing (23). Seals (24 to 26) ensure the tightness of the circulation of the liquid and gaseous phases, for example, water and air.

[0036] The head of the moving part (30) has, in the described example, two water diffusion segments (35, 36) along an axial direction and a thread for mounting a nozzle with a central outlet (48) for supplying the fluid of the first phase, in the described example, air, and a peripheral outlet (102) for supplying pressurized air. It also includes a peripheral conduit (49) for supplying the nozzle, allowing the arrival of the second phase. The annular longitudinal chamber (32) allows the liquid phase, which entered through (13) and was distributed by an annular distribution chamber (36), to enter.

[0037] In the example described, the rotating body (30) is driven by a propeller (50) placed in the water flow, the passage of which creates a rotary motion. Description of an example of a nozzle

[0038] The description of the example nozzle illustrated in [Fig. 4] is not limiting. The invention is intended to work with different types of two-phase diffusion nozzles.

[0039] The nozzle is traversed by a main axial channel (100) opening into the coaxial mixing chamber (105). This main channel (100) extends from an eccentric threaded fitting (101) to a ring (104) opening into the mixing chamber (105).

[0040] The ring (104) ensures the transmission of the two fluids from the head of the rotating body to the mixing chamber (105). It comprises the main channel (100), arranged along the longitudinal axis of the intermediate body and the mixing chamber (105), and one or more secondary conduits (102, 103), typically a bundle of secondary conduits extending from the threaded fitting (101) to the inlet of the mixing chamber (105). These secondary conduits (102; 103) are oriented along axes (113, 114) forming an angle of approximately 10°, typically between 8 and 15°, with respect to the longitudinal axis (10).

[0041] Other configurations may be provided, for example a conical annular chamber extending from the fitting (101) to an annular outlet in the inlet of the mixing chamber (105). This conical chamber may be partitioned longitudinally to ensure the rigidity of the peripheral walls.

[0042] The mixing chamber (105) forms a so-called Laval nozzle. It is formed by a straight duct with a variable cross-section, consisting of a convergent section (106) extended by a divergent section (107) with a constriction (108) between these two parts (106, 107).

[0043] The convergent part (106) is configured so that an annular zone (108) is in the extension of the axes (113, 114) of the secondary conduits respectively (102, 103).

[0044] This configuration is essential for the liquid jet to break on the surface of the convergent part (106) and atomize the liquid flow into droplets projected into the central vein in the jet of the gaseous phase and create turbulence in the convergent part (107) before being carried by the central vein through the throat (108) into the divergent part (106) of the so-called Laval nozzle.

Claims

Demands

1. - A device for generating a two-phase fluid jet comprising at minus a rotating nozzle, characterized in that it comprises: • a fixed base (10) having: • a central connection (14) for connecting a first-phase inlet emerging in the center of the inner surface of said fixed base, • a peripheral connection (13) for connecting a second-phase supply emerging at the periphery, in an annular area, of the inner surface of said fixed base • a fixed body (20), integral with said base, comprising • a central conduit (34) for the passage of said first phase, • surrounded by a coaxial annular chamber (32), for the passage of said second phase, • a body (30) rotating about an axis corresponding to the longitudinal axis of said fixed body (21), having at least one rotating joint disposed in the interface with said fixed body; • said rotating body (30) having a fitting for receiving a two-phase diffusion nozzle (40), having a longitudinal axis (41) not aligned with the longitudinal axis (21) with said fixed body (20); • a central conduit (48) for supplying the nozzle with said first phase opening onto the upstream face of said body through an opening into said central conduit (34) • and at least one peripheral conduit (49), communicating with said coaxial annular chamber, for the passage of said second phase, • said body comprising a means of rotational drive relative to said fixed body (20).

2. - Device for generating a two-phase fluid jet according to claim- dication 1 characterized in that said first phase is air under pressure.

3. - Device for generating a two-phase fluid jet according to claim 1 characterized in that said second phase is water.

4. - A device for generating a two-phase fluid jet according to claim 1 or 2, characterized in that said drive means consists of a helical shape positioned in the peripheral conduit

5. - A two-phase fluid jet generation device according to claim 1 characterized in that said drive means consists of an electric motor mechanically coupled to said rotating body.

6. - A two-phase fluid jet generation device according to claim 1 characterized in that said drive means consists of a hydraulic motor mechanically coupled to said rotating body.

7. - A two-phase fluid jet generation device according to claim 1 characterized in that said drive means consists of a magnetized ring attached to said rotating body, interacting electromagnetically with a wound peripheral stator.

8. - A two-phase fluid jet generation device according to claim 1 characterized in that said drive means is a pneumatic or hydraulic motor.

9. - A two-phase fluid jet generation device according to claim 1 characterized in that said rotating body comprises at least one nozzle having a main conduit (100) supplied by a pressurized gaseous fluid and opening into a mixing chamber (105), as well as at least one secondary conduit (102, 103) supplied by at least one pressurized liquid fluid opening into said mixing chamber (105) in a direction forming a non-zero angle with the axis of said main conduit.

10. - A two-phase fluid jet generation device according to the preceding claim, characterized in that said mixing chamber (105) has a convergent-divergent cylindrical wall having a constriction (108) defining an opening in the plane perpendicular to the axis of said main conduit, the convergent part (106) of said wall having a frustoconical zone in the extension of the axis of said at least one secondary conduit (102; 103), to form a liquid phase fragmentation chamber.

11. - Device for generating a two-phase fluid jet according to claim- the previous dication characterized in that the axis (113, 114) of said at least one secondary conduit (102; 103) forms with the axis of said main conduit (100) an angle between 2° and 20°.

12. - A two-phase fluid jet generation device according to the preceding claim characterized in that the axes (113, 114) of the secondary conduits (102, 103) define with the generatrix of the cone of the converging part (106) an angle between 0° and 60° and preferably of 45° ±10°.

13. - A device for generating a two-phase fluid jet according to claim 10 characterized in that the diameter of said opening of the constriction (108) is between 0.8 and 1.2 times the diameter of said main conduit.

14. - A device for generating a two-phase fluid jet according to claim 1 characterized in that said nozzle(s) have a mixing chamber (105) forming a so-called Laval nozzle.

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