Deceleration device with vortex effect for flows made up of an injection system with jet-type intersecting atomisers

Abstract

The present invention describes a deceleration device with vortex effect for flows made up of an injection system with jet-type atomisers, consisting of an atomising system, which is formed by jet-type atomisers intersectingly arranged around a cylindrical chamber, the jets of which consecutively collide with each other, causing the velocity at which the jets were expelled from their respective nozzles to be significantly reduced. A nebulised and rotational flow is caused as a result of the collisions, which flow circulates at the centre of the chamber at low speeds. The work fluid may range from liquid water at low temperatures to cryogenic fluids such as nitrogen. The novelty of this invention lies in the rotational nebulisation that is intended to preserve edible products for longer. Moreover, in the event of failure, this device is easy to repair as it is made up of removable parts that can be repaired or replaced if required. Furthermore, the angle "β" can be widened, which allows adjustments to be performed with regards to the intensity of the mist inside the deceleration cylinder.

Description

[0001] WHIRL EFFECT DEACCELERATION FOR FLOWS CONFORMED BY A DRYING ATOMIZER INJECTION SYSTEM TYPE

[0002] JET

[0003] TECHNICAL FIELD

[0004] The present invention is based on jet-type atomizers and the vortex effect, where it should be noted that both techniques have had wide application in combustion areas; however, in the present invention, it should be noted that the vortex effect will be achieved through channels arranged in a secant direction (represented by the jet atomizers), which will cause the vortex or whirlwind effect to be decelerated.

[0005] BACKGROUND OF THE INVENTION

[0006] The present invention is based on jet-type atomizers and the vortex effect, where it should be noted that both techniques have had wide application in combustion areas; however, in the present invention, it should be noted that the vortex effect will be achieved through channels arranged in a secant direction (represented by the jet atomizers), which will cause the vortex or whirlwind effect to be decelerated.

[0007] The closest antecedents found are the following:

[0008] D1 : Patent document No. W09801708A1 for Multiple Swirl Combustion Chamber Plate; by Ryan William R.; with publication date: 15-01-1998; document D1 discloses a combustion chamber plate with multiple swirls, for efficient air-fuel mixing; that is, positioned around multiple and concentric circles on the plate; all this, with the intention of reducing NOx emissions (Nitrogen oxides) produced in gas turbine engines. It should be noted that the mixture of fluids before passing through the vortex fins, do so previously in an axial manner.

[0009] D2: Patent document No. WO201 1 133420A2 for Swirl pressure atomizer with swirl assist configuration, by Bamber Daniel W.; Ambrose Steven L.; Stretch Dale A., with publication date: 27-10-2011 ; document D2 discloses a device that operates under the physical principle of a fluid with rotational movement, which is achieved when a fluid is injected at a certain pressure, through a number of channels distributed tangentially around an enclosure (vortex chamber).

[0010] D3: Publication article (Ayala et al, Design of a Cryogenic Duplex Pressure- Swirl Atomizer through CFDs for the Cold Conservation of Marine Products, Fluids 2023 Oct 1 ; 8(10): 271 , https: / / doi.org / 10.3390 / fluids8100271 . This article proposes the design of a duplex atomizer (consisting of two centrifugal atomizers with tangential inlets); where each atomizer will work with liquid water and liquid nitrogen respectively, leaving it known that the small-sized atomizer corresponds to the liquid nitrogen one, both atomizers operate under the principle of conservation of angular motion, which causes conical-shaped sprays to form at their respective outlets. The imminent collision of both sprays causes the atomized liquid nitrogen (fluid at low temperatures) to remove heat from the water droplets, causing the liquid water to pass to the solid state (ice).

[0011] D4: Publication article (Ronceros et al, Study of Internal Flow in Open-End and Closed Pressure-Swirl Atomizers with Variation of Geometrical Parameters, Aerospace 2023 Oct 31 ; 10(1 1 ): 930, https: / / doi.org / 10.3390 / aerospace 101 10930. This article studies the geometric variations of the centrifugal atomizer with tangential inlets; that is, how the internal flow and the spray angle of this type of atomizer behave depending on the number of tangential channels and the opening parameter (which classifies centrifugal atomizers as open or closed).In this study, six different centrifugal atomizers were used (different numbers of channels and opening parameters), which gave a better understanding of the internal flow behavior, showing that when the number of tangential channels increased, greater stability was achieved in the conical spray and more uniform mass distribution at the atomizer outlet.

[0012] The following problems are found in the aforementioned background:

[0013] The invention shown in D1 is a device used in the combustion area and the flow inlet is made in an axial direction (parallel to the axis of the system); then, the flow will experience a form of multiple swirls, which guarantees greater turbulence and mixing of fuel and oxidants, the swirl effect is predominantly present. However, the chamber used to house this system would have to have a greater length so that the residence time of the air-fuel mixture is greater within said chamber.

[0014] The invention shown in D2 is a device that produces a whirlpool effect because the channels through which the fluid enters are distributed tangentially around the internal walls of the cylindrical chamber. However, in the proposed invention, by adopting this criterion of considering the inlet channels as tangential, they would cause the jet of nebulized fluid to be influenced by the change in temperature, due to friction with the internal walls of the cylinder and this will produce a phase change, where the nebulized fluid will quickly condense. For this reason, in the present invention, the inlet channels are proposed in a "dry" manner to the cylindrical walls of the device, which will only cause the jets of nebulized fluids to impact consecutively, causing only deceleration and no phase change, that is, there will be no contact of the nebulized jets with the walls (friction with the walls will be avoided).At the same time, the cylindrical chamber will be prevented from having considerable lengths.

[0015] The article published in D3 shows two atomizers with their respective chambers, each used to house different fluids: a cryogenic liquid fluid (liquid nitrogen) and a fluid in a liquid state at room temperature (water). Both atomizers operate with tangential channels, the intention of which is to impart an angular motion to both fluids, achieving that, when expelled, conical sprays are produced at their respective outlets. This device, therefore, is more suitable for liquid fluids, and it is worth clarifying that atomization occurs at the outlet. However, in the proposed invention, atomization occurs internally, because the drying channels are already atomizing devices (Jet-type atomizers).

[0016] D4, a mathematical model is shown whose usefulness is for the design of centrifugal atomizers with tangential channels, this mathematical model relates the mass flow, pressure differential, discharge coefficient and spray angle, based on important geometric parameters in their design. However, here also the atomization is achieved at the exit of the device and is more focused on working with liquid fluids, highlighting the difference that the device proposed here produces a nebulizing effect of the fluids inside its cylindrical chamber, through the drying channels, which behave at the same time as Jet type atomizers.

[0017] BRIEF DESCRIPTION OF THE INVENTION

[0018] Based on the foregoing, in order to overcome the disadvantages of the aforementioned background, the present invention proposes a vortex effect decelerator for flows formed by a jet-type atomizer injection system. The present invention is specifically developed with the objective of reducing the velocity of atomized / nebulized liquid fluids. This decelerator is composed of a cylindrical chamber with a circular section, around the perimeter of which is installed an injection system consisting of a plurality of jet-type atomizers, which are positioned angularly equidistant from one another; furthermore, these atomizers enter the circular perimeter of the decelerator chamber in a secant manner.

[0019] On the other hand, the deceleration of the total flow is carried out by impacting a jet of atomized liquid with the jet of the immediately subsequent atomizer, and so on until the atomization ring is closed, producing the nebulization of the fluids throughout the decelerator chamber, highlighting that this effect can be achieved with a minimum of three atomizers (atomizers positioned in an equilateral triangle format), the nebulizing effect will be appreciated more pronouncedly in the center of the cylinder, where the nebulized fluid streams will describe a rotational movement or jet effect at low speeds.Finally, this slowdown will ensure that the nebulized fluids have a longer residence time in the cylindrical chamber. These fluids can be conditioned to operate at different temperatures and pressures, which is convenient in various areas, such as food preservation areas, which rely on cold processes and require low temperatures to ensure their preservation for a much longer period.

[0020] The jet-type atomizer is a circular section channel where the injected liquid will experience a change in area or "choke" at the outlet of the atomizer (nozzle), which will produce instability in the liquid, due to the high speeds at which it is expelled, achieving atomization. It is true that, in the first instance, the purpose of atomization is achieved; However, the problem persists that the fluid is at high speeds, therefore, a solution for the deceleration would be to "brake" it, through the idea of ​​​​impacting the jet ejected from an atomizer with a neighboring jet, but in a strategic manner, that is, so that "braking" is achieved and at the same time that the direction of the resulting jet does not impact the internal walls of the cylinder that houses the desiccant atomizers.That is why it is proposed that the position of these atomizers be distributed in a secant direction around the cylindrical chamber and entering it in a secant manner, so that the vortex effect does not occur on the walls of the chamber, but rather closer to the center of the chamber, where a nebulization flow will be visualized, a product of the multiple impact of the atomized jets, achieving that the flow in the center is rotational and decelerated.

[0021] The jet type atomizer (See sketch in Fig.1), is a removable piece where the fluid will enter axially or parallel to the axis of symmetry of the atomizer, these atomizers will be located around the perimeter of a circular section of the cylindrical chamber (Fig.2); At the same time, these atomizers fulfill the role of fluid inlet channels into the cylindrical chamber and are distributed in an angularly equidistant and secant manner (Fig. 3), the removal of the atomizers will facilitate maintenance and cleaning in case of clogging by particles foreign to the working fluid. It should be remembered that the channels when entering in a secant manner, will guarantee the angular movement of the flow inside the cylindrical chamber and as a result of the collisions of the jets, a nebulization will be obtained at slow rotational speeds, which will guarantee a longer residence time inside the cylinder.

[0022] Finally, the proposed invention is oriented toward the cold storage industry; it should be noted that it can also be used in the combustion area, due to the longer residence time and uniform mixing that reactive fluids would experience. DETAILED DESCRIPTION OF THE INVENTION

[0023] The present invention has as a novelty, the use of an atomization system consisting of jet type atomizers, where due to the drying position, oriented by an angle They will cause an impact of jets suitable for producing the nebulization of a flow that is rotational and slow, achieving greater flow residence time, where it should be noted that the intention of the greater flow residence time is conducive to being used in the area of ​​refrigeration and food preservation.

[0024] The swirl decelerator for flows consisting of a jet-type desiccant atomizer injection system consists of:

[0025] - Feeding system, consisting of the inlets (2) of the jet-type atomizers, to the decelerating chamber (5) (Fig. 2 and Fig. 3).

[0026] - A decelerating chamber (5), which houses the removable jet-type atomizers (1), positioned periodically around the perimeter of the cylindrical chamber (4), through whose outlet (6), the nebulized flow will slowly expand into the environment (Fig. 2).

[0027] - Jet type atomizers (1), which are characterized by presenting a decrease in area section at its exit, commonly referred to as nozzle (3), these atomizers must be in number greater than or equal to three units, imaginarily forming a figure with regular sides between them, in this case 8 units are shown (octagon). It should be noted that these atomizers enter the circular section in a secant manner, oriented by an angle which is inscribed in the “xy” plane, and results from positioning the “imaginary axis” of the atomizer parallel to the “x” axis (Fig. 3).

[0028] The vortex effect decelerator for flows is made up of a jet-type desiccant atomizer injection system, which are removable and the number can be variable (greater than or equal to 3 units), and they are also oriented in a secant manner by the angle “ ”, which we will call “vortex angle”, and we can vary it according to the design requirements.

[0029] • The liquid fluid, through injection pressure, enters through the inlet sections (2), and is expelled from the jet atomizer (1), through the nozzles (3), at considerable speeds, due to the decrease in area presented by the atomizer outlet.

[0030] • The atomized fluid or jet that is expelled from the nozzles (3) will impact the adjacent jet and so on, they will impact periodically and around the circular perimeter (4).

[0031] • A nebulized flow will be produced, resulting from the multiple impacts of the jets; this flow will have a rotational movement at low speeds and will be more noticeable in the center of the deceleration chamber (5), where it will slowly seek the exit of the cylinder (6), until it joins the atmosphere or environment.

[0032] It can then be stated that the slower the nebulizing current, the longer the flow residence time, which, by presenting a rotational movement, will facilitate the uniform conservation of the edible product at low temperatures, where it should be noted that this invention can be modified to scale if the conditions of quantities to be refrigerated so require.

[0033] BRIEF DESCRIPTION OF THE FIGURES

[0034] Fig. 1. Sketch of the jet-type atomizer, showing the entry of the liquid fluid at the inlet velocity “Uent” and being expelled in the form of a jet through the nozzle with the outlet velocity “Usai”.

[0035] Fig. 2. Perspective view of the decelerating cylinder, showing its walls (5), and inside it are displayed: jet-type atomizers (1), atomizer inlets (2), atomizer outlet or nozzles (3), perimeter of the circular section where the atomizers are located (4) and outlet of the nebulized flow (6).

[0036] Fig. 3. Atomization system consisting of jet-type atomizers, with drying inlet, in plan view, where the angle is displayed the jet-type atomizers (1), the cylinder inlets (2), the atomizer nozzles (3), and the perimeter of the circular section of the chamber (4).

[0037] Fig. 4. Plan view of the deceleration chamber, showing the velocity contour (m / s) of the atomizer jets and the center of the chamber, using Ansys Fluent 2023.

[0038] Fig. 5. Perspective view of the deceleration chamber, showing the streamlines and velocities (m / s) of the flow caused by the eddy effect, using Ansys Fluent 2023.

[0039] Fig. 6. Plan view of the deceleration chamber, showing the liquid / air interface, using the “Volume of Fluid” multiphase VOF model (present in Ansys Fluent); liquid fluid is colored red and air is colored blue.

[0040] PREFERRED EMBODIMENT OF THE INVENTION

[0041] The present invention is susceptible to embodiment in many different forms. The drawings and preferred description show in detail a preferred embodiment of the invention. However, it should be understood that the drawings and preferred description of one embodiment are to be considered as a particular exemplification of the principles of the invention and are not intended to limit the broad technical aspects of the present invention to the particular embodiment. A preferred embodiment of the invention is described below in accordance with Figures 1 through 6.

[0042] In Fig. 1, a sketch shows the expulsion of the atomized fluid in the form of a jet at "Usai" speed, which, when colliding with the jets of the surrounding atomizers, will cause a nebulized flow in rotational form (finely atomized water in a continuous medium: air), where the surfaces of the food will be uniformly covered, guaranteeing its conservation.

[0043] In Fig. 2, the decelerating cylinder is shown, where the nebulizing current will be formed inside at low speeds and in a rotational manner (vortex effect), causing the flow to take longer to leave the chamber, that is, a longer residence time is achieved.

[0044] Figure 3 shows in detail the location of the drying channel (jet type atomizer), with respect to the "x" axis, where it is important to emphasize that the design of the atomization system depends on the angle and that to achieve the swirl effect at low speeds, the impact of the jets will be necessary, where the minimum amount for this phenomenon to occur must be three atomizers. The tangential component "W" of the jet velocity at the nozzle exit can be related to the angle using equation 1 , where “Usa” is the jet velocity. Remember that the velocity “U” depends on the nozzle exit cross-sectional area and the continuity equation.

[0045] W = U sai . senp (1)

[0046] Figure 4 shows a top view of the decelerator, where the velocity contour can be seen using the numerical simulation software Ansys Fluent. The flow behavior obeys the angular motion equation (equation 2), and it can be seen that the highest velocities are recorded at the nozzle exit (10.94 m / s), which then decelerate as they approach the center of the chamber. It is worth mentioning that the assumed inlet velocity for all atomizers was 2 m / s.

[0047] W. r = cte (2)

[0048] Where “W” is the tangential velocity component of the fluid exiting the nozzle and “r” is the radial distance from the center of the cylinder to the atomizer nozzle.

[0049] Figure 5 shows the deceleration chamber in perspective view, where the streamlines simulated with Ansys Fluent 2023 software show the rotational movement decelerating as the flow approaches the center of the chamber.

[0050] In Figure 6, you can see in plan view, the numerical simulation of the liquid / air interface, using the Volume of Fluid (VOF) model, belonging to Ansys Fluent, where the atomized liquid (red color), is spread in the continuous medium (air, blue color), where the periodic behavior of the atomized fluids is clearly visualized, it is also clearly shown that the drying position of these atomizers is convenient so that the atomized fluid does not collide against the internal walls of the cylinder, and is directed with the objective of producing the nebulization.

[0051] What is desired to protect the vortex effect decelerator for flows formed by jet type desiccant atomizer injection system (Fig. 2 and Fig. 3) includes:

[0052] - An atomization system consisting of jet-type atomizers (1), in whose inlets (2), the working fluid in liquid phase is injected under pressure, to then obtain the atomized fluid through the nozzles (3). Highlighting that the most important part of this invention is the periodic position of the atomizers around the perimeter of the chamber (4), entering in a secant manner and influenced by the angle where this angle will be emphasized as it is the main geometric parameter of this invention.

[0053] - A cylindrical chamber (5), whose perimeter (4), will be used for the insertion of the drying channels (1), oriented in a secant manner according to the angle Inside this chamber, the vortices or swirling phenomenon of the nebulized flow will originate at low rotation speeds, remaining like this until it completely expands at the cylinder outlet (6).

[0054] It is important to mention that the main geometric parameter of this invention (angle “ / 3”) has a suitable range for the whirlpool phenomenon to occur: 15°< ?< 90°.

[0055] RESULTS OBTAINED.

[0056] It is worth noting that eight jet-type atomizers were used in this proposal, with the number of atomizers being an important factor in the formation of the vortex, that is, as the number of drying channels increases, the homogenization of the atomized mass in the center of the cylinder is better. We worked with the help of numerical simulation, using the computational software Ansys Fluent, which gives us a more detailed prediction of the behavior of the fluids inside the cylindrical deceleration chamber; in this case, liquid water was used as the working fluid in the inlet sections of the atomizers and an inlet velocity of 2 m / s was considered (Uent = 2 m / s). In addition, the angle "(3" used in these simulations was 50° ( ?=50°).The results of the numerical simulation are presented in Figures 4 to 6, where it is important to highlight that the k-epsilon turbulence model and the Volume of Fluid (VOF) multiphase model were used to locate the liquid / air interface. All these models are implemented in Ansys Fluent 2023. ADVANTAGES OF THE SWIRL EFFECT DEACCELERATION FOR FLOWS SHAPED BY A JET-TYPE ATOMIZER INJECTION SYSTEM.

[0057] • Its intended use in the food preservation area will benefit the previous processes of a cold chain, that is, due to the atomization system implemented inside the cylinder, the food stored inside said cylinder can be uniformly covered with a thin, cold layer.

[0058] • The atomization system is innovative, as the high jet velocities are reduced due to the sequential impact of the jets, leaving as a product of such collisions a nebulized rotational flow, flowing at low speeds, conducive to increasing the residence time within the chamber.

[0059] • This invention has removable parts (jet-type atomizers), which can be easily maintained or replaced. We can also increase the number of these parts (channels or atomizers) and position them in a secant manner to the circular perimeter, according to the appropriate or design angle "ft".

[0060] • Longer food preservation time, and can be used as a working fluid for atomization from ice water to liquid nitrogen.

[0061] OPERATION OF THE WHIRL EFFECT DEACCELERATION FOR FLOWS SHAPED BY A JET-TYPE ATOMIZER INJECTION SYSTEM

[0062] During operation of the decelerator, the liquid fluid is injected and distributed through the drying channels, which also atomize the fluid through their nozzles. The atomized fluid, or jet, will impact the surrounding jet and so on until the atomizer ring is closed. This position of the channels is strategic so that the atomized fluid does not impact the chamber walls and the collisions are transformed into a nebulized stream whose movement is rotational and at low speeds, ensuring that the nebulized flow has a longer residence time in the cylindrical chamber.

Claims

CLAIMS 1. A swirl decelerator for flows formed by a jet-type atomizer injection system, of the type comprising at least three removable jet-type atomizers (1), each atomizer with an inlet (2) through which the liquid fluid at low temperatures enters and an outlet with its respective nozzle (3) to expel the fluid in the form of a jet; the decelerator is characterized in that it comprises a cylindrical chamber inside which it has a cooling zone, with a flow of nebulized fluid in slow and rotational movement, 2. A swirl decelerator for flows formed by a jet-type atomizer injection system, according to claim 1, characterized in that the working fluid may be refrigerant and / or cryogenic fluids.

3. A swirl decelerator for flows formed by a jet-type atomizer injection system; according to claim 1; characterized in that the atomizers are removable.

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