Two-phase spray jet nozzle

Abstract

The present invention relates to a device for generating a two-phase fluid jet, comprising a rotary nozzle, the device comprising a fixed base (10) having a central connector (14) for connecting an inlet for a first phase, opening centrally on the inner surface of the fixed base, and peripheral connectors (13) for connecting inlets for a second phase, opening peripherally in an annular region of the inner surface of the fixed base, a fixed body (20) fixed to the base, the fixed body (20) having a central channel (34) for the passage of the first phase, surrounded by a coaxial annular chamber (46) for the passage of the second phase, and at least one rotary nozzle, rotatable about an axis corresponding to the longitudinal axis (21) of the fixed body and arranged at the interface with the fixed body. The invention is characterized in that it comprises a body (30) with a rolling joint, the rotating body (30) having a connector for receiving a two-phase diffusion nozzle (40), the body (30) having a longitudinal axis (41) not aligned with the longitudinal axis (21) of the stationary body (20), a central channel (100) for feeding a first phase to the nozzle, the central channel (100) having ports opening in the upstream face of the body through openings in the central channel, and at least one peripheral channel (102) communicating with a coaxial annular chamber for the passage of a second phase, the body (30) having means for being driven in rotation relative to the stationary body.

Description

[Technical Field]

[0001] The present invention relates specifically to the field of generating and propelling a two-phase mixture of at least one gas and liquid for fire extinguishing, equipment cooling, and mist formation. The mixture is created in a nozzle, where the interaction of a high-velocity gas stream with a jet of water atomizes the water droplets in the water jet to form a mist of very small or microscopic droplets, thereby forming a two-phase mixture of water mist droplets driven and carried by the gas flow. When the relative flow velocity between the two fluids is high, inertial forces result in the formation of bubbles or droplets.

[0002] Such two-phase mixtures exhibit significant cooling performance, suppressing damage caused by water and water vapor by causing low levels of localized wetting and eliminating any ambient disturbances. These mixtures are produced by fixed equipment located, for example, in ceilings of industrial, tertiary or residential buildings, tunnels, passenger cabins of airplanes or ships, or in the cabs / cockpits of aircraft pilots or industrial equipment operators, or in industrial site-based or forestry facilities, or by portable equipment in the form of fire hoses operated by firefighters or autonomous vehicles.

[0003] The finer the atomization and the higher the droplet velocity, the higher the kinetic energy of the droplets and the greater their ability to penetrate the center of the fire. As the heat exchange surface increases, the cooling and inertization all become greater. High-pressure water mist also blocks radiant heat. This allows, for example, temperatures to remain tolerable just a few meters from the center of an 800°C fire, and dampens the shock waves caused by, for example, an explosion.

[0004] The gas supplied to the nozzle may be an inert gas such as nitrogen, carbon dioxide, argon, or simply air, or oxygen. [Background technology]

[0005] WO 2022 / 090662 describes an earlier invention by the same inventor. It describes a fire hose supplied by a two-phase supply line, with a nozzle that can be optionally extended by a deformable spray tip, with a multifunction control handle and optional peripheral elements, for example, to form a portable device. This system includes a convergent-divergent mixing chamber that opens directly into the deformable tip, which is connected in a sealed manner, without any passage of air coming from outside the nozzle. The purpose is to form a mist of water droplets with a cross section of less than 400 micrometers, preferably less than 90 micrometers, sprayed axially.

[0006] US Patent Application Publication No. 20180264486 relates to a device for single-phase spraying of liquid chemicals, including pesticides such as insecticides or nutrients, on four sides through a nozzle structure that is rotated so that the liquid chemical spraying device can be placed on a flat surface such as the ground or a desk.

[0007] WO 2021 / 156125 relates to a single-phase rotary atomizer designed to spray a liquid through a rotating disc. The disc is designed to rotate about an axis centered at the disc center. A liquid applicator is designed to apply the liquid to the surface of the disc. A spray guide assembly partially surrounds the disc. The inner surface of the spray guide assembly is designed to modify the trajectory of any liquid emerging from the outer edge of the disc. Summary of the Invention [Problem to be solved by the invention]

[0008] The object of the present invention is to make it possible to flexibly orient the spray axis, which is provided axially in the solution proposed by WO 2022 / 090662, so as to direct the two-phase jet in the appropriate direction, regardless of the orientation of the device, and to make it possible to control the direction when the device is fixed (mounted on a ceiling or wall, or on a mobile machine) or possibly handheld.

[0009] The problem is that generating a two-phase jet results in a geometry without axisymmetric upstream sections, while the rotating head solutions proposed by US Patent Application Publication No. 20180264486 and WO 2021 / 156125 relate to single-phase solutions with a single supply line axially arranged to the upstream section and to the inlet of the rotating head. It is not possible to adapt the rotating heads known from these two prior art documents to a two-phase structure in which axisymmetric only exists at the nozzle after mixing of the two liquid and gas phases. [Means for solving the problem]

[0010] It is an object of the present invention to create a high performance spray nozzle capable of dispersing a two-phase mist, particularly for fire fighting applications.

[0011] To this end, the invention relates to a device for generating a two-phase fluid jet having the features of claim 1.

[0012] This device is A fixed base, a central connector for connecting the inlet of the first phase, opening in the center of the inner surface of the fixed base; a fixed base having a peripheral connector for connecting a second phase inlet opening at the periphery in an annular zone on the inner surface of the fixed base; A fixed body fixed to a base, Surrounded by a coaxial annular chamber for the passage of the second phase, a fixed body with a central channel for the passage of the first phase; a body rotatable about an axis corresponding to the longitudinal axis of the fixed body and having at least one rotational joint arranged at the interface with the fixed body, the body has a connector for receiving a two-phase diffusion nozzle, the connector having a longitudinal axis that is not aligned with the longitudinal axis of the stationary body; a central channel for supplying the first phase to the nozzle, the central channel having ports opening in the upstream face of the body through openings in the central channel; a rotary nozzle comprising a body having at least one peripheral channel communicating with a coaxial annular chamber for the passage of a second phase, This body comprises means for being driven in rotation relative to the fixed body.

[0013] Preferably, the first phase is pressurized air.

[0014] Preferably, the second phase is water.

[0015] According to a first embodiment, the means for being driven are constituted by a helix positioned in the peripheral duct.

[0016] According to a second embodiment, the means for being driven are constituted by an electric motor mechanically coupled to the rotating body.

[0017] According to a third embodiment, the means for being driven are constituted by a hydraulic motor mechanically coupled to the rotating body.

[0018] According to a fourth embodiment, the means for being driven are constituted by a magnetized ring fixed to the rotor and interacting electromagnetically with a stator wound around its periphery.

[0019] According to a fifth embodiment, the means for being driven are pneumatic or hydraulic motors.

[0020] According to one embodiment, the rotating body comprises at least one nozzle having a main duct supplied with a pressurized gaseous fluid and opening into the mixing chamber, and at least one secondary duct supplied with at least one pressurized fluid and opening into the mixing chamber in a direction forming a non-zero angle with the axis of the main duct.

[0021] Advantageously, the mixing chamber has a converging-diverging cylindrical wall with a constriction defining an opening in a plane perpendicular to the axis of the main duct, the tapered portion of the wall having a frustoconical zone in the extension of the axis of at least one secondary duct to form a liquid phase fragmentation chamber.

[0022] In one variant, the axis of at least one secondary duct forms an angle of between 2° and 20° with the axis of the main duct.

[0023] In another variant, the axis of the secondary duct subtends an angle of 0° to 60°, preferably 45°±10°, with the generatrix of the cone of the tapered section.

[0024] Advantageously, the diameter of the constricted opening is 0.8 to 1.2 times the diameter of the main duct.

[0025] In a particular embodiment, the nozzle has a mixing chamber forming a so-called Laval nozzle. [Brief explanation of the drawings]

[0026] The invention will be better understood on reading the following description, which refers to non-limiting exemplary embodiments illustrated by the accompanying drawings, in which: [Figure 1] 1 shows a front view of a first exemplary embodiment of a device according to the invention; [Figure 2] 1 shows a front view of a second exemplary embodiment of a device according to the invention; [Figure 3] 1 shows a cross-sectional view of a device according to the invention. [Figure 4] 1 shows a longitudinal section of a device according to the invention; [Figure 5]1 shows a perspective view of a device according to the invention; DETAILED DESCRIPTION OF THE INVENTION

[0027] The description of one of these items naturally extends to a subassembly including that element in combination with another element, even if the first element is not described in detail again in the section relating to the detailed description of the other element. Similarly, each of the elements can be used with complementary elements other than those described or even the subject of this patent, the nozzles that are the subject of this patent can be extended by tips other than those proposed by this patent, and likewise, the tips described can be used with nozzles other than those of this patent. The same applies to all elements in the detailed description.

[0028] General principles of the present invention The present invention relates to a two-phase fluid generator that can be orientated at an angle oblique to the longitudinal axis of an upstream base (10) that provides liquid and gas supplies, is rotatably articulated to a downstream rotor (30), and is fitted with one or more nozzles (40, 45) for dispersing a two-phase jet. The formation of the two-phase jet from a main duct supplying a first fluid phase and one or more secondary ducts supplying a second fluid phase different from the first fluid phase is carried out either within this downstream rotor (30) or, preferably, in one or more nozzles with two-phase mixers mounted on this downstream rotor (30) that transport each of the fluid phases through two separate ducts.

[0029] The interface between the upstream base (10) and the downstream rotor (30) is a main axial duct passing through the base (10) and a main axial duct passing through the rotor (30) at an angle to the axis of the base; It is configured to ensure fluid continuity between the secondary ducts in the base (10) and the secondary ducts in the rotor (30).

[0030] For this purpose, the main axial duct passing through the rotor (30) may be elbow-shaped, having an axially upstream portion in the extension of the main axial duct passing through the base (10) and a downstream portion oriented along the longitudinal axis of the nozzle attached to this rotor (30), or several downstream portions when the body comprises several nozzles.

[0031] In the case of secondary ducts eccentric to the main duct, an advantageous solution is to provide annular grooves in the base (10) and / or the rotor (30), which communicate upstream with the secondary ducts of the base and upstream with the secondary ducts of the rotor (30).

[0032] Description of Exemplary Embodiments of Nozzles Figure 1 shows a front view of the first variant with a rotating nozzle 40. The device comprises a base 10 supported by legs 11, 12 for mounting on a pedestal or ceiling.

[0033] The fixed part, comprising the base (10) and the body (20), has a cylindrical shape with a longitudinal axis (21). The rotating body (30) is extended by nozzles (40) whose longitudinal axis (41) forms an angle of approximately 55° with the longitudinal axis (21) of the fixed part. In the embodiment shown, it features a series of axial nozzles (31).

[0034] The inner rotating part of the stationary body 20 is fitted with a gear 52 which is driven by the output pinion 51 of an electric, hydraulic or pneumatic motor. Of course, the drive can also be provided by a chain or belt system.

[0035] FIG. 2 shows an alternative configuration having two rotating nozzles (40, 45) oriented along axes (41, 42) whose rotation defines a cone coaxial with the longitudinal axis (21).

[0036] Functional Description The base (10) has two threaded holes (13, 14) for connecting pressurized water and air supplies respectively. The connections are shown on the front face, but one or both could also be radial.

[0037] The rotor (30) is extended by a cylindrical rod characterized by two coaxial ducts: an annular longitudinal chamber (32) separated by a cylindrical partition (33) and a central duct (34), which is designed to feed a nozzle for the arrival of the first phase.

[0038] The annular longitudinal chamber (32) allows the liquid phase entering via (13) to flow into the annular distribution chamber.

[0039] The water supply hole (13) opens into an annular distribution chamber (36) formed by a flare in the annular longitudinal chamber (32). The fixed rod (31) is guided relative to the rotor (30) by rear bearings (22) and front bearings (23). Seals (24-26) ensure leak-proofness of the flows of liquid and gas phases, such as water and air.

[0040] The head of the moving part (30) has, in the described embodiment, two axial water diffusion segments (35, 36) and a screw thread for mounting a nozzle having a central outlet (48) for supplying the first phase fluid, in the described embodiment air, and a peripheral outlet (102) for supplying pressurized air. It also features a peripheral duct (49) for feeding the nozzle for the arrival of the second phase. The annular longitudinal chamber (32) enters via (13) and allows the liquid phase to be distributed by the annular distribution chamber (36).

[0041] In the embodiment described, the rotor (30) is driven by a propeller (50) placed in the water current, the passage of which creates rotational motion.

[0042] Exemplary Nozzle Description The description of the exemplary nozzle shown in Figure 4 is non-limiting. The present invention is designed to work with different types of two-phase diffusion nozzles.

[0043] The nozzle is crossed by an axial main channel (100) that opens into a coaxial mixing chamber (105). The main channel (100) extends from an eccentric screw joint (101) to a ring (104) that opens into the mixing chamber (105).

[0044] The ring (104) provides the communication of the two fluids from the head of the rotor to the mixing chamber (105). It comprises a main channel (100) arranged along the longitudinal axis of the intermediate body and the mixing chamber (105), and one or more secondary ducts (102, 103), typically a bundle of secondary ducts extending from the threaded joint (101) to the inlet of the mixing chamber (105). These secondary ducts (102, 103) are oriented along axes (113, 114) that form an angle of approximately 10°, typically 8-15°, with the longitudinal axis (10).

[0045] Other configurations may be provided, for example a conical annular chamber extending from the joint (101) to the annular outlet in the inlet of the mixing chamber (105), which may be partitioned longitudinally to ensure peripheral wall rigidity.

[0046] The mixing chamber (105) forms the tip of a so-called Laval nozzle, which is formed by a straight duct of variable cross section, consisting of a convergent section (106) followed by a divergent section (107), with a constriction (108) between these two sections (106, 107).

[0047] The tapered portion (106) is configured so that the annular region (108) is in continuation of the axes (113, 114) of the respective secondary ducts (102-103).

[0048] This configuration is essential for the liquid jet to impact the surface of the convergent portion (106), atomizing the droplet stream projected into the central vane in a gaseous jet, and creating turbulence within the convergent portion (107) before being driven by the central vane through a neck (108) in the divergent portion (106) of the Laval nozzle.

Claims

1. 1. A device for generating a two-phase fluid jet comprising at least one rotating nozzle, A fixed base (10), a central connector (14) for connecting the inlet of the first phase, opening centrally on the inner surface of said fixed base; a fixed base (10) having a peripheral connector (13) for connecting a second phase inlet opening at the periphery in an annular zone of the inner surface of the fixed base (10); a fixed body (20) fixed to said base, surrounded by a coaxial annular chamber (32) for the passage of said second phase, a stationary body (20) provided with a central channel (34) for the passage of said first phase; a body (30) rotatable about an axis corresponding to the longitudinal axis of said fixed base (10) and having at least one rotational joint arranged at the interface with said fixed base (10), the rotating body (30) has a connector for receiving a two-phase diffusion nozzle (40) and a longitudinal axis (41) that is not aligned with the longitudinal axis (21) of the stationary body (20); a central channel (48) for supplying the first phase to the nozzle, the central channel (48) opening at the upstream face of the body through an opening opening into the central channel (34); a body (30) having at least one peripheral channel (49) communicating with said coaxial annular chamber for the passage of said second phase, A device for generating a two-phase fluid jet, wherein this body comprises means for being driven in rotation relative to said fixed body (20).

2. 2. The device for generating a two-phase fluid jet according to claim 1, wherein the first phase is pressurized air.

3. 2. The device for generating a two-phase fluid jet according to claim 1, wherein the second phase is water.

4. 3. A device for generating a two-phase fluid jet according to claim 1 or 2, characterized in that the means for being driven comprise a helix positioned in a peripheral duct.

5. 2. The device for generating a two-phase fluid jet according to claim 1, characterized in that said means for being driven comprises an electric motor mechanically coupled to said rotating body.

6. 2. The device for generating a two-phase fluid jet according to claim 1, characterized in that said means for being driven comprises a hydraulic motor mechanically coupled to said rotating body.

7. 2. The device for generating a two-phase fluid jet according to claim 1, characterized in that the means for being driven are constituted by a magnetized ring fixed to the rotor and electromagnetically interacting with a stator wound around its periphery.

8. 2. A device for generating a two-phase fluid jet according to claim 1, characterized in that said means for being driven are pneumatic or hydraulic motors.

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

10. 10. The device for generating a two-phase fluid jet according to claim 9, characterized in that the mixing chamber (105) has a converging-diverging cylindrical wall with a constriction (108) defining an opening in a plane perpendicular to the axis of the main duct, the tapered portion (106) of the wall having a frustoconical zone in the extension of the axis of the at least one secondary duct (102, 103) to form a liquid phase fragmentation chamber.

11. 11. The device for generating a two-phase fluid jet according to claim 10, characterized in that the axis (113, 114) of the at least one secondary duct (102, 103) forms an angle of between 2° and 20° with the axis of the main duct (100).

12. 12. The device for generating a two-phase fluid jet according to claim 11, characterized in that the axes (113, 114) of the secondary ducts (102-103) define an angle with the generatrix of the cone of the tapered portion (106) of between 0° and 60°, preferably 45°±10°.

13. The device for generating a two-phase fluid jet according to claim 10, characterized in that the diameter of the opening of the constriction (108) is 0.8 to 1.2 times the diameter of the main duct.

14. 2. The device for generating a two-phase fluid jet according to claim 1, characterized in that the nozzle has a mixing chamber (105) forming a Laval nozzle.

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