FR2822935A1 - METHOD FOR DIFFUSING AIR BY MODULES USED ALONE OR ASSOCIATED IN DIFFUSERS OF DIFFERENT TYPES - Google Patents

Abstract

The present invention relates to a method of air diffusion by vector modules, used alone or associated in diffusers of different types, making it possible to obtain a constant and homogeneous mass flow whatever the temperature of the air and to simultaneously control the breath effects. The module according to the invention is composed, on the air inlet side, of an extended air rectifier grid (g), on the air outlet side, by flaps (h) and (i) orientable along two perpendicular axes; the assembly is incorporated in an asymmetrical or symmetrical frame (c) and can be oriented around the axis of rotation (d). The residual air speed o perceived at a certain distance from the module and at constant mass flow rate depends on the setting of the flaps (h) and (i): the more the jet is expanded, the lower the residual speed perceived. The combination of several modules makes it possible to create an infinite variety of air diffusers, either in single flow, for heating or cooling the ambient air in recycling, or in double flow, for air purification ambient with maintaining the balance between the internal pressure of the room and the external pressure (extract air = fresh air).

Description

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The present invention relates to an air diffusion method by vector modules used alone and more generally associated in diffusers of different types and making it possible to deliver a constant and homogeneous mass air flow whatever the air temperature and to control breath effects simultaneously.

The diffusion of air in a closed room has two main functions: - It is to heat or cool the internal atmosphere of the room. In this case, the diffused air will be taken from inside the premises, heated or cooled as appropriate by an appropriate exchanger and then diffused into the premises. We are recycling the internal air in the room.

 - It is also a question of cleaning up the internal atmosphere of the room. It is always necessary to renew the air by introducing outside air, called "fresh air, and simultaneous extraction of polluted internal air. The diffusion of the fresh air is carried out after preheating or cooling. A good renewal of air is that where an extraction is compensated by an introduction of air outside the room in equal or slightly greater quantity.

- A good diffusion will be that which will ensure the best possible mixture of the diffused air with the ambient air, the greatest homogeneity of internal temperature and especially without blowing effect. In small rooms, housing and offices for example, the air diffusion is facilitated by the effects of the walls on the air jet diffused in the room: the diffused air tends to stick to the walls and thus better spread out in the room. In large premises, industrial premises or equivalent, these wall effects are generally non-existent or negligible: the diffusion is done in free fields. It is also verified that the best way to diffuse free field air in a room is vertical diffusion from top to bottom. The consequences of the gravity effect are better understood by appropriate air velocities and jet orientations. It is however necessary to satisfy the two imperatives which are the homogenization by induced effect, which conditions the effect of mixing, is the control of the effects of breath, which conditions the comfort.

Among the processes of the prior art, two of them have been technically preponderant: The first process, known as "cyclone effect", consists in transforming a vertical jet into three components: a radial component, a component tangential and a

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 vertical axial component called residual component. A cyclone effect is thus obtained, embodied in particular by a central depression from the top to the bottom due to the expansion of the jet and a rotation of the air masses - the effect of mixing by induced effect is certain. However, the residual vertical axial speed, which cannot be reduced sufficiently, imposes minimum installation heights for each device flow rate which it is unwise to transgress and, although representing a great improvement over traditional solutions, the cyclone effect is still directive.

The adjustment range and adaptability to the site remain insufficient.

The second method, known as a "vortex jet", consists in simultaneously implementing several horizontal dart jets tangential to a circular wafer. When the diffused air has a density equal to that of the ambient air, the dart jets will be simultaneously deflected downwards according to the installation height of the diffuser and the internal dimensions until the desired effect is obtained . If the air is lighter, that is to say warmer and / or more humid, it will be enough to increase as much as necessary the angle of deflection downwards of the jets in dart to obtain the desired effect.

If the air is heavier, ie colder and / or drier, the angle of vertical deflection of the dart jets will be reduced until the desired diffusion is obtained. The inclination can be zero or even negative, the air will descend by gravity. The air diffused by each of the dart jets mixes by induced effect with the ambient air.

On the other hand, due to the relative expansion of the jets, a vertical depression is created, from the bottom to the top, in the center of the vortex jet. Finally, all of the dart jets entrain viscosity of the surrounding air masses which, thus rotated, will infiltrate all internal obstacles. In a single flow configuration, the mixture of recycled air with ambient air for heating or cooling without any noticeable blast effect is better. This extends the adjustment range of the devices and their adaptability is significantly increased.

This vertical central depression from the bottom up, noted in the two aforementioned processes, is much greater in the vortex jet. It was possible to open the center of the diffuser jet and to establish a coaxial extraction duct from the bottom to the top. The jet thus obtained becomes a double-flow system: the forced air comes from outside the building, the vertical central depression pulls upward the air masses located in the area, the influence of the vortex jet and brings them to catchment range of the extraction mouth. The incoming flow compensates for the outgoing flow,

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 such a system operates in pressure balance. If the area covered by the vortex jet is a polluted area, the system concentrates the effluents in the center of the jet, bringing them to the extraction range through the central mouth. This polluted air is then extracted and can then be treated appropriately. The set of downward-facing dart jets acts as a hood. Each of the dart jets constitutes the element of a partition wall between the zone of influence of the vortex jet and the surrounding external zones. You get a sort of ventilation hood by analogy to a hood with full walls. Measurements carried out on site have given encouraging results in the case of fine particles suspended in the air (oil mist, light effluents, hot polluted air, etc.).

In single-flow use, the diffusion of air in a vortex jet is the source of some progress in terms of quality of mixture by induced effect, in terms of comfort and finally in terms of facilities for adaptation to sites and facilities for setting.

However, a differentiated distribution of the speed of ejection of air from each mouth was noted: the air going faster on the outside. I throw in dart is deformed and loses part of its advantages: the orientation by shutters is limited and the effects of breath (residual speeds at a distance from the mouths) can become random.

We find this same drawback in double flow use. The homogeneity of the walls of the ventilation hood is insufficient to ensure good separation between the core of the vortex and the external environment. This results in leakage zones through which the effluents to be extracted can escape, especially in the case of heavier particles.

All the air diffusion methods, and in particular the two aforementioned methods, are effective for a given diffused air speed, therefore for a determined volume flow rate. This is incompatible with the notion of pressure balance in a room or the extraction of polluted air and the introduction of fresh air, which are subject to generally large temperature differences, must be treated in mass flow.

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By its modular design, the present invention is innovative: -The residual speed of each module is adjustable to allow, at constant mass flow, to control the residual speed at will and thus to control the effects of breath.

- The speed at the outlet of each module is homogeneous and the shape of the jet is adjustable relative to the neighboring module and vice versa and the resulting vector is orientable.

- The modules can thus be associated with each other to constitute simple or double flow distribution sets standardized or adapted to each case to be treated.

The present invention aims to allow the realization of single flow diffusers and dual flow diffusers adapted to the specific characteristics of each site to be treated, the fact of being able, from a standard module, to adapt the applications of the invention to all situations without penalizing the costs of adaptation and implementation, gives the invention a major industrial and economic interest.

A form of implementation of the present invention will be described below, by way of nonlimiting example, with reference to the appended drawings: FIGS. 1 and 2 represent the complete module according to the invention according to the two asymmetric models and symmetrical.

Figures 3 and 4 show the diffusion grid of a module.

Figures 5 and 6 show two of the various possibilities for adjusting the diffusion grid.

The adjustment of the orientation of the complete asymmetrical or symmetrical module is represented by FIGS. 7a, 7b, 8a and 8b.

Figures 9,10, 11,12 and 13 show by way of nonlimiting examples some of the possible arrangements of diffusers from the module object of the present invention.

The module according to the invention (fig. 1 and fig. 2) is composed of a diffusion grid (a) incorporated in an asymmetrical (b) or symmetrical (c) frame. The diffusion grid (a) is integral with its frame, (b) or (c), via an axis of rotation (d) which allows directional adjustment along a plane perpendicular to said axis and along a single direction and with greater incidence in the case of the framework

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 asymmetrical (b), and in two symmetrical directions in the case of a symmetrical frame (c). The diffusion grid (fig. 3 and fig. 4) includes the sides (e), horizontal in the representation, forming with the sides (f) a frame in which is supported, on the air inlet side, a fixed grid (g ) composed of perpendicular elements of an appropriate and sufficient width for the grid to act as an air rectifier. At the exit of the fixed grid (g), the air is divided into as many equal speed vectors as there are meshes in the grid and which can be deflected at will by the adjustable flaps (h) and (i) in rotation of axes according to the air outlet generators of the fixed grid (g). The differentiated inclinations of the flaps (h) on the one hand, and (i), on the other hand, allow all types of adjustment of the aforementioned speed vectors: FIG. 4 represents an adjustment according to which the jets are concentrated on a focal point. so that the residual velocities at the focus point add up; FIG. 5 represents an adjustment according to which the speed vectors are dispersed in two directions so that the residual speed of the resulting vector is reduced compared to the residual speeds of each speed vector. Thus, for a given air mass, the cumulative dynamic pressures of each jet at the outlet of the fixed grid is constant and varies more or less as one moves away from the air outlet orifice . When the setting is nominal, there is an accumulation of dynamic pressures of each speed vector; when the focus adjustment on a given point away from the mouth, the dynamic pressure increases at this point, while in the case of a relative expansion of the different speed vectors the dynamic pressure perceived at a given point away from the mouth will tend towards the individual dynamic pressure of each jet perceived at this point.

One of the aims sought is thus obtained, which is the control of the residual speeds perceived at constant mass flow and at variable volume flow. In the same way that it will be possible to expand the jet on both sides and thus to obtain a controlled overlap with the jet of a neighboring module adjusted in the same way in order to homogenize the air wall thus formed.

We have seen that the module according to the invention is composed of a diffusion grid (a) incorporated in an asymmetrical (b) or symmetrical (c) frame. The diffusion grid (a) is integral with its frame, (b) or (c), by means of an axis of rotation (d) allows directional adjustment along a plane perpendicular to said axis and following

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 only one direction but with a greater incidence in the case of the asymmetrical frame (b), and along two symmetrical directions in the case of a symmetrical frame (c). Figures 7a and 7b, 8a and 8b show these possibilities which are added to the possibilities of previous settings.

The combination of several modules thus makes it possible to create an infinite variety of single or double flow air diffusers. Figures 9 to 13 show some examples given without limitation.

FIG. 9 represents an example of a diffuser made up of ten modules according to FIG. 2 and mounted at 450 on a diffuser body (j) and in which air is introduced at the top, diffused by the modules at an initial speed which depends the overall volume flow and the number of modules. In this case we can, for example, ensure the homogeneity of the diffusion by the aforementioned unidirectional flaring of the jets of each module, control the importance of the vertical central depression by a directional adjustment of each module and thus, bring within range of capture of the extraction (k) the air enclosed in the global jet. Similarly, such a diffuser can be used in single flow, in which case the extraction mouth (k) will be replaced by a closed face.

FIG. 10 represents another type of diffuser using modules according to FIG. 1 and mounted according to a vertical generator (the body of the diffuser is not shown). In this case, in addition to the uniformity of diffusion which is obtained in an identical manner to the previous case, the following module in FIG. 1 facilitates adjustment of the diffusion in a cone oriented downwards. The modules being of square section, these can be turned to 900 in one direction or the other to generate a jet comparable to the vortex jet mentioned above but more homogeneous.

FIG. 11 represents another arrangement of modules according to FIG. 1 in which another possibility of dissemination is offered which can be in single or double stream. The same is true for Figure 12.

In all the above-mentioned cases, the modules are distributed over the periphery of a circular diffusion body. It is also against possible to distribute the modules on a rectangular or elliptical diffuser body so as to cover a rectangular area; a conventional hood on the lower lips of which the modules are arranged in a homogeneous air curtain becomes a semi-aeraulic hood which jointly ensures the pressure balance of the room. Such a device is shown in Figure 13, or the body of the diffuser is also not shown.

Claims (1)

 CLAIMS - 1-Method of air diffusion by vector modules, used alone or in diffusers of different types, where the control of the residual velocities of the air jet, at constant mass flow, is ensured by the division of the air jet overall in partial air jets whose velocity vectors are either concentrated at a point distant from the source to increase the overall speed at this point, or, more generally, expanded to reduce the blast effects perceived at this point.  - 2-module for implementing the method according to claim 1 characterized in that it comprises a fixed grid (g) which acts as an air rectifier and which divides the overall jet into as many partial jets rectified as there are meshes in the fixed grid and in that it comprises an extension of the fixed grid (g) a set of orientable flaps (h) and (i) allowing, by relative expansion of the velocity vectors of the partial jets or by focusing of said vectors, to control, at constant mass flow, the residual speed perceived at a point distant from the mouth. - 3-Vector module according to claim 2 characterized in that the fixed grid assembly (g) and adjustable flaps (h) and (i) is mounted in an asymmetrical (b) or symmetrical (c) frame allowing orientation around an axis of rotation (d) of the diffusion grid with respect to the frame and according to the two possibilities: a large inclination and in one direction for the asymmetrical frame (fig 7), a lower inclination but in two directions for a symmetrical frame (fig 8). - 4-Single flow diffuser with vertical blowing from top to bottom characterized in that several modules according to claims 2 and 3 are distributed around the periphery of a cylindrical body or of a truncated cone (j) whose apex is oriented towards the bottom and in which air is introduced on the upper face of the cylinder or cone and then diffused by the modules, the lower face being closed. - 5-Single flow diffuser with vertical blowing from top to bottom characterized in that several modules according to claims 2 and 3 are distributed on a horizontal plane in a circle, a rectangle or an ellipse and where air is introduced on the <Desc / Clms Page number 8>  upper face of the device then distributed by the modules, the lower face being closed. - 6-Double flow diffuser characterized in that the underside of a diffuser according to one of the two preceding claims is opened by a vertical coaxial extraction mouth. - 7-Diffuser according to one of the three preceding claims, characterized in that the vector modules are either of the asymmetrical type (fig 1) or of the symmetrical type (fig 2) and of square front section and can be oriented identically according to a angle of 0, 900, 1800 or 270. - 8-Diffuser according to claims 5, 6, 7 and 8 characterized in that the shape of the jet emitted by a module can be expanded tangentially so as to be brought into contact with the jet emitted by the neighboring module and adjusted in the same way in such a way that the air curtain thus created is homogeneous.