EP3401547B1 - Low pressure radial blower - Google Patents

Description

The invention relates to a centrifugal fan with low pressure air extraction reaction, as for example described in the document US2006/228212 A1 .

The field of the invention is the field of low pressure air extraction, and more particularly the field of fans at a total pressure less than 150 Pa.

STATE OF THE ART

Ventilation systems, provided for smoke extraction, aeration, etc. must have a high extraction efficiency and a reduced noise level, particularly in buildings for professional, commercial or residential use.

To reduce noise pollution, exhaust fans designed for total pressures greater than 500 Pa are used for extracting air at total pressures less than 150 Pa. However, these fans are not designed for extracting air at total pressures below 150 Pa, they remain noisy and their efficiency is reduced.

An aim of the present invention is to remedy these drawbacks.

Another aim of the present invention is to provide a less noisy fan.

Another aim of the present invention is to propose a fan having better efficiency compared to fans of the state of the art.

Another aim of the present invention is to provide a fan specifically designed for extracting air at total pressures less than 150 Pa.

STATEMENT OF THE INVENTION

At least one of the aforementioned objectives is achieved by a centrifugal reaction fan according to claim 1.

• le rayon d'entrée, et
• la tangente à ladite aube au niveau du bord d'entrée,

peut être compris entre 60° et 75°.In one embodiment of the fan according to the invention, for at least one blade, an angle, called the inlet pitch angle, formed by:

• the entry radius, and
• the tangent to said blade at the inlet edge,

can be between 60° and 75°.

Such an inlet pitch angle makes it possible to reduce noise and increase fan efficiency at total pressures less than 150 Pa.

According to the invention, the blades are curved so that said fan is a reaction fan. In other words, the blade moves away from the center of the fan in the direction opposite to the direction of rotation of the fan.

• le rayon d'entrée, respectivement de sortie, et
• la tangente au cercle passant par ladite aube, au niveau du bord d'entrée, respectivement de sortie.

In this case, the entry angle, respectively at the exit, is formed by:

• the entry radius, respectively exit radius, and
• the tangent to the circle passing through said blade, at the level of the inlet edge, respectively outlet edge.

• d'une part 90 mm, plus particulièrement 100 mm, encore plus particulièrement 110 mm, et
• d'autre part 130 mm, plus particulièrement 120 mm, encore plus particulièrement 115 mm.

In particular, the entry radius of at least one blade can be between:

• on the one hand 90 mm, more particularly 100 mm, even more particularly 110 mm, and
• on the other hand 130 mm, more particularly 120 mm, even more particularly 115 mm.

More particularly, the inlet radius of at least one blade can be equal to 113 mm.

In an alternative embodiment, the entry radius of at least one blade can be equal to 93 mm.

These two values make it possible to obtain a fan with better efficiency and lower noise.

• d'une part 150 mm, particulièrement 170 mm, plus particulièrement 180 mm, encore plus particulièrement 200 mm, et
• d'autre part 250 mm, particulièrement 230 mm, plus particulièrement 220 mm, encore plus particulièrement 212 mm.

Preferably, the exit radius of at least one blade can be between:

• on the one hand 150 mm, particularly 170 mm, more particularly 180 mm, even more particularly 200 mm, and
• on the other hand 250 mm, particularly 230 mm, more particularly 220 mm, even more particularly 212 mm.

In particular, the outlet radius of at least one blade can be equal to 209 mm.

The exit radius of at least one blade may be equal to 205 mm.

These two values make it possible to obtain a fan with better efficiency and lower noise.

• d'une part 60°, plus particulièrement 65°, et
• d'autre part 75°, plus particulièrement 73°.

In one embodiment of the fan according to the invention, the pitch angle at the inlet of at least one blade can be between:

• on the one hand 60°, more particularly 65°, and
• on the other hand 75°, more particularly 73°.

Particularly, the pitch angle at the inlet of at least one blade can be equal to 70° and more particularly equal to 69°.

These two values make it possible to obtain a fan with better efficiency and lower noise.

In one embodiment of the fan according to the invention, the pitch angle at the outlet of at least one blade can be equal to 70° and more particularly equal to 76°.

These two values make it possible to obtain a fan with better efficiency and lower noise.

Advantageously, the fan according to the invention can comprise an odd number of blades between 5 and 11, in particular equal to 7.

The number of blades can be equal to 5.

In a preferred embodiment of the fan according to the invention, the height of at least one blade on the inlet edge side can be between 60 mm and 180 mm.

In particular, the height of at least one blade on the inlet edge side may be equal to 100 mm.

Furthermore, the height of at least one blade on the inlet edge side may be equal to 95 mm.

In a preferred embodiment of the fan according to the invention, the height of at least one blade on the outlet edge side can be between 60 mm and 180 mm.

In particular, the height of at least one blade on the outlet edge side may be equal to 100 mm.

Furthermore, the height of at least one blade on the outlet edge side may be equal to 95 mm.

Preferably, the suction inlet may be circular in shape having a diameter of between 200 mm and 400 mm, in particular equal to 330 mm and more particularly equal to 315 mm.

• d'une part 200 mm, plus particulièrement 260 mm, encore plus particulièrement 310 mm, et
• d'autre part 400 mm, plus particulièrement 360 mm, encore plus particulièrement 340 mm.

In particular, the diameter of the suction inlet can be between:

• on the one hand 200 mm, more particularly 260 mm, even more particularly 310 mm, and
• on the other hand 400 mm, more particularly 360 mm, even more particularly 340 mm.

In an advantageous embodiment of the fan according to the invention, the lower flange and at least one blade can form a single piece.

In particular, the lower flange and at least one blade can be made by molding.

Alternatively, the lower flange and at least one blade can be assembled by welding, screwing or any other means of fixing.

The lower flange may include an opening for fixing a motor configured to drive the rotation of the fan according to the invention.

Advantageously, all the blades can be identical.

Alternatively, at least two blades may have different dimensions, such as inlet radii, outlet radii, pitch angles, etc. different.

Advantageously, the fan according to the invention can have a rotation speed of between 300 rpm and 900 rpm.

Furthermore, the extraction flow rate of the fan according to the invention can be less than 2000 m ³ /h.

In particular, at least one, in particular each, blade of the fan according to the invention can be beveled.

This shape of at least one blade makes it possible to increase the efficiency of the fan according to the invention for the extraction of air at a flow rate of between 1000 m ³ /h, in particular 1500 m ³ /h, and 2500 m ³ /h, in particular 2000 m ³ /h.

• au moins un ventilateur selon l'invention,
• au moins un moteur prévu pour entraîner la rotation dudit au moins un ventilateur.

According to another aspect of the invention, a device is proposed for extracting air at a total pressure less than 150 Pa, comprising:

• at least one fan according to the invention,
• at least one motor designed to drive the rotation of said at least one fan.

In particular, the motor can be connected to the lower flange on which at least one, in particular all, of the fan blade(s) are arranged.

• une ouverture d'entrée d'air vers le ventilateur, agencée axiale par rapport audit ventilateur,
• une ouverture de sortie d'air, depuis le ventilateur, agencée radiale par rapport audit ventilateur,

caractérisé en ce que l'ouverture de sortie radiale est située en regard dudit ventilateur et s'étend autour dudit ventilateur, sur au moins 50% du périmètre dudit ventilateur.According to another aspect of the invention, there is proposed a ventilation device intended for the extraction of air at a total pressure less than 150 Pa, comprising at least one fan according to the invention, arranged in a structure, said structure comprising for at least one fan:

• an air inlet opening towards the fan, arranged axially with respect to said fan,
• an air outlet opening, from the fan, arranged radially relative to said fan,

characterized in that the radial outlet opening is located opposite said fan and extends around said fan, over at least 50% of the perimeter of said fan.

The ventilation device according to the invention makes it possible to increase the air extraction efficiency at total pressures less than 150 Pa° and to reduce the noise of the ventilation device.

DESCRIPTION OF THE FIGURES AND EMBODIMENTS

• la FIGURE 1 est une représentation schématique d'un exemple de réalisation non limitatif d'un ventilateur selon l'invention ;
• la FIGURE 2 est une vue d'en haut du ventilateur de la FIGURE 1 ;
• la FIGURE 3 est une vue de côté d'un exemple de réalisation limitatif d'une aube d'un ventilateur selon l'invention ;
• la FIGURE 4 est une représentation schématique d'un exemple non limitatif d'un dispositif selon l'invention ; et
• les FIGURES 5a et 5b sont des représentations schématiques d'un exemple non limitatif d'un dispositif de ventilation selon l'invention.

Other advantages and characteristics will appear on examination of the detailed description of non-limiting examples of embodiment, and of the appended drawings in which:

• there FIGURE 1 is a schematic representation of a non-limiting embodiment of a fan according to the invention;
• there FIGURE 2 is a view from above of the fan of the FIGURE 1 ;
• there FIGURE 3 is a side view of a limiting embodiment of a blade of a fan according to the invention;
• there FIGURE 4 is a schematic representation of a non-limiting example of a device according to the invention; And
• THE FIGURES 5a and 5b are schematic representations of a non-limiting example of a ventilation device according to the invention.

It is understood that the embodiments which will be described below are in no way limiting. In particular, it will be possible to imagine variants of the invention comprising only a selection of characteristics described subsequently isolated from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention from the prior art. This selection includes at least one preferably functional characteristic without structural details, or with only part of the structural details if this part only is sufficient to confer a technical advantage or to differentiate the invention compared to the state of the prior art.

There FIGURE 1 is a schematic representation of a non-limiting embodiment of a fan according to the invention.

The fan 100 comprises a flange 102, called lower, and a flange 104, called upper. The upper flange 104 includes a circular opening, called suction inlet 106, provided for the passage of air.

The fan 100 also includes 7 blades 108 curved in a direction opposite to the rotation of the fan 100. Each blade 108 is defined by an inlet edge 110 ₁ , located towards the center of the fan 100 and an outlet edge 110 ₂ located in periphery of the fan 100. In addition, the blades 108 of the fan 100 are identical.

The upper flange 104 may be removable, while the lower flange 102 and the blades 108 may form a single piece.

There FIGURE 2 is a view from above of the fan of the FIGURE 1 .

On the FIGURE 2 , the upper flange 104 has been omitted for greater clarity and to allow visual access to the blades 108.

The fan 100 includes a radius 202 ₁ , called an inlet radius, corresponding to the radius of the circle 204 ₁ passing through the inlet edges 110 ₁ of all the blades 108. The inlet radius 202 ₁ is between 90 mm and 130 mm, in particular equal to 113 mm.

The fan 100 includes a radius 202 ₂ , called an outlet radius, corresponding to the radius of the circle 204 ₂ passing through the outlet edges 110 ₂ of all the blades 108. The outlet radius 202 ₂ is between 150 mm and 250 mm, in particular equal to 209 mm.

The fan 100 comprises, for each blade 108, an angle 206 ₁ , called the inlet pitch angle, formed by on the one hand the inlet radius 202 ₁ and on the other hand the tangent 208 ₁ to said blade 108 at the level of its inlet edge 110 ₁ . For each blade 108, the inlet setting angle 206 ₁ is between 60° and 75°, in particular equal to 70°.

The fan 100 comprises, for each blade 108, an angle 206 ₂ , called the outlet pitch angle, formed by on the one hand the outlet radius 202 ₂ and on the other hand the tangent 208 ₂ to said blade 108 at the level of its exit edge 110 ₂ . For each blade 108, the outlet angle 206 ₂ is between 70° and 80°, in particular equal to 70°.

In addition, the fan 100 comprises a fixing means 210, at the level of the lower flange 102, intended to connect said fan 100 to a motor not shown on the FIGURE 2 . The fixing means 210 may comprise an opening for fixing a transmission shaft and screw holes provided for fixing said transmission shaft to the fan 100.

There FIGURE 3 is a side view of a non-limiting embodiment of a blade of a fan according to the invention.

The Dawn 300, shown on the FIGURE 3 , can be a blade 108 of the fan 100.

The blade 300 is defined by an inlet edge 302 ₁ located towards the center of a fan comprising it and an outlet edge 302 ₂ located at the periphery of said fan.

The blade 300 has a height 304 ₂ at its outlet edge 302 ₂ which decreases to a height 304 ₁ towards the inlet edge 302 ₁ according to the length of the blade 300. The blade 300 is therefore beveled in shape.

The height 304 ₁ is between 60 mm and 180 mm, in particular equal to 70 mm.

The height 304 ₂ between 60 mm and 180 mm, in particular equal to 100 mm.

Alternatively to what is shown on the FIGURE 3 , the height 304 ₁ can be equal to the height 304 ₂ so that the height of the blade remains constant over its entire length.

The thickness of the blade 300 is between 0.3 mm and 10 mm, in particular equal to 0.8 mm.

The blade 300 can be made of metal or a metal alloy, for example steel, aluminum, or polymers, for example polypropene.

The blade 300 can be produced by machining or foundry.

There FIGURE 4 is a schematic representation of a non-limiting example of a device according to the invention.

The device 400 is intended for the extraction of air at total pressures less than 150 Pa. The device 400 includes the fan 100 of the FIGURES 1 and 2 .

In addition, the device 400 comprises a motor 402 connected to the fan 100 by a transmission shaft 404. The motor 402 is intended to drive the rotation of the fan 100, in particular at a speed between 300 rpm and 900 rpm .

The device 400 can be arranged in an air extraction installation in a residential building for example.

THE FIGURES 5a and 5b are schematic representations of a non-limiting example of a ventilation device according to the invention.

There FIGURE 5a is a perspective view of a ventilation device 500, while the FIGURE 5b is a sectional view of the ventilation device 500 of the FIGURE 5a .

The ventilation device 500 includes the fan 100 of the FIGURES 1 and 2 arranged in a structure 502. The structure 502 comprises an air inlet opening 504 provided for the passage of air with a view to its extraction by the fan 100. The device 500 comprises a tap 506 provided to connect the opening of air inlet 504 to an ventilation duct, for example of a ventilation installation comprising the device 500.

The structure 502 also includes an air outlet opening 508 located opposite the fan 100 and extends radially around the fan 100. The air outlet opening 508 covers 95% of the perimeter of the fan 100.

The device 500 comprises two removable feet 510 arranged to support the structure 502.

The device 500 further comprises a motor 512, arranged in the structure 502, and connected to the fan 100 by a transmission shaft 514. The motor 512 is designed to drive the rotation of the fan 100, in particular at a speed between 300 rev /min and 900 rpm.

The device 500 comprises a control means 516 intended to control the rotation speed of the fan 100 for example as a function of a pressure and/or an air temperature. The control means 516 includes an emergency stop button for the device 500 intended to stop the fan 100 in the event of a malfunction or emergency.

For example, the device 500 can be arranged on the roof of a building and connected to the aeraulic network of said building.

Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without departing from the scope of the invention which is defined by the following claims.

Claims (12)

1. A centrifugal fan (100) for extracting air at a total pressure of less than 150 Pa, comprising:

   - a so-called lower flange (102), of circular shape, and a so-called upper flange (104), and

   - a plurality of blades (108; 300) arranged between said flanges (102; 104), each blade (108, 300) comprising a so-called inlet edge (110₁; 302₁) located toward the center of said fan (100) and a so-called outlet edge (110₂; 302₂) located at the periphery of said fan (100);

   each blade being curved so that said fan (100) is a reaction fan, wherein, for each blade (108; 300):

   - a so-called inlet radius (202₁), defined between the center of said fan (100) and the inlet edge (110₁; 302₁) of said blade (108; 300), is between 90 mm and 130 mm, and

   - a so-called outlet radius (202₂), defined between the center of said fan (100) and the outlet edge (110₂; 302₂) of said blade (108; 300), is between 150 mm and 250 mm, characterized in that for each blade:

   - an angle (206₂), called the outlet setting angle, formed by:

   ∘ the outlet radius (202₂), and

   ∘ the tangent (208₂) to said blade (108; 300) at the outlet edge (110₂; 302₂),

   is between 70° and 80°.
2. The fan (100) according to the preceding claim, characterized in that, for each blade (108; 300), a so-called inlet angle (206₁), formed by:

   - the inlet radius (202₁), and

   - the tangent (208i) to said blade (108; 300) at the inlet edge (110₁; 302₁),

   is between 60° and 75°.
3. The fan (100) according to any one of the preceding claims, characterized in that the inlet radius (202₁) of each blade (108; 300) is between:

   - on the one hand 90 mm, more particularly 100 mm, even more particularly 110 mm, and

   - on the other hand 130 mm, more particularly 120 mm, even more particularly 115 mm.
4. The fan (100) according to any one of the preceding claims, characterized in that the outlet radius (202₁) of each blade (108; 300) is between:

   - on the one hand 150 mm, particularly 170 mm, more particularly 180 mm, even more particularly 200 mm, and

   - on the other hand 250 mm, particularly 230 mm, more particularly 220 mm, more particularly 212 mm.
5. The fan (100) according to any one of claims 2 to 4, characterized in that the inlet setting angle (206₁) of each blade (108; 300) is between:

   - on the one hand 60°, more particularly 65°, and

   - on the other hand 75°, more particularly 73°.
6. The fan (100) according to any one of the preceding claims, characterized in that it comprises an odd number of blades (108, 300) between 5 and 11, in particular equal to 7.
7. The fan (100) according to any one of the preceding claims, characterized in that the height (304₁) of each blade (108; 300) on the inlet edge side (110₁; 302₁) is between 60 mm and 180 mm.
8. The fan (100) according to any one of the preceding claims, characterized in that the height (304₂) of each blade (108; 300) on the outlet edge side (110₂; 302₂) is between 60 mm and 180 mm.
9. The fan (100) according to any one of the preceding claims, characterized in that the upper flange comprises an opening (106), called a suction eye, provided for the passage of air in a direction substantially perpendicular to said upper flange (104), said suction eye (106) being circular in shape and having a diameter of between 200 mm and 400 mm, in particular equal to 315 mm.
10. The fan (100) according to any one of the preceding claims, characterized in that its rotational speed is between 300 rpm and 900 rpm.
11. A device (400) for extracting air at a total pressure of less than 150 Pa, comprising:

    - at least one fan (100) according to any one of the preceding claims,

    - at least one motor (402) provided to rotate said at least one fan (100).
12. A ventilation device (500) for extracting air at a total pressure of less than 150 Pa, comprising at least one fan (100) according to any one of claims 1 to 10, arranged in a structure (502),
    said structure (502) comprising, for at least one fan (100):

    - an air inlet opening (504) toward the fan (100), arranged axially with respect to said fan (100),

    - an air outlet opening (508), from the fan (100), arranged radially with respect to said fan (100),

    characterized in that the radial outlet opening (508) is located opposite said fan (100) and extends around said fan (100) over at least 50% of the perimeter of said fan (100).

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