FR3066235B1 - CENTRIFUGAL FAN FOR LOW PRESSURE AIR EXTRACTION. - Google Patents

Abstract

The invention relates to a centrifugal fan (100) for extracting air at a pressure of less than 150 Pa, comprising: - a lower flange (102) of circular shape and an upper flange (104), and at least one blade (108) arranged between said flanges (102; 104) and comprising an inlet edge (1101) located towards the center of said fan (100) and an outlet edge (1102) located on the periphery of said fan (100); characterized in that for at least one blade (108): - an input radius, defined between the center of said fan (100) and the input edge (1101) of said blade (108), is between 90 mm and 130 mm, and - an output radius, defined between the center of said fan (100) and the output edge (1102) of said blade (108), is between 150 mm and 250 mm. The invention also relates to a device for extracting air at low pressure.

Description

The invention relates to a centrifugal fan for extracting air at low pressure.

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

STATE OF THE ART

Ventilation systems, intended for smoke extraction, ventilation, etc. must have a high extraction efficiency and a low noise level, especially in buildings for professional, commercial or residential use.

To reduce noise, extraction fans designed for total pressures greater than 500 Pa are used for the extraction of air at total pressures of less than 150 Pa. However, these fans are not designed for Air extraction at total pressures below 150 Pa, they remain noisy and their performance is reduced.

An object of the present invention is to overcome these disadvantages.

Another object of the present invention is to provide a quieter fan.

Another object of the present invention is to provide a fan having a better performance compared to fans of the state of the art.

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

SUMMARY OF THE INVENTION

At least one of the aforementioned objectives is achieved by a centrifugal fan, designed for the extraction of air at a total pressure of less than 150 Pa, in particular less than 80 Pa, comprising: - a so-called lower flange, circular in shape and a flange, said upper, said upper flange comprising in particular an opening, called a suction inlet, provided for the passage of air in a direction substantially perpendicular to said upper flange, and - at least one blade arranged between said flanges and comprising an edge, said input, located towards the center of said fan, and an edge, said output, located on the periphery of said fan; characterized in that for at least one blade: - a radius, said input, defined between the center of said fan and the inlet edge of said blade, is between 90 mm and 130 mm, and - a radius, said output, defined between the center of said fan and the output edge of said blade, is between 150 mm and 250 mm.

With the fan according to the invention, its dimensions, in particular the input radius and the output radius, are configured for extraction of air operation at a total pressure of less than 150 Pa. The inventors have found that the The fan according to the invention has a higher extraction efficiency and a lower noise compared to fans of the state of the art. The fan according to the invention therefore has a better performance and is designed specifically for the extraction of air at low pressure.

In one embodiment of the fan according to the invention, for at least one blade, an angle, called the angle of entry, formed by: - the input radius, and - the tangent to said blade at the edge of the d entry, can be between 60 ° and 75 °.

Such an input pitch angle can reduce noise and increase fan efficiency at total pressures below 150 Pa.

In an embodiment of the fan according to the invention, for at least one blade, an angle, called the angle of exit timing, formed by: - the output radius, and - the tangent to said blade at the output edge can be between 60 ° and 85 °.

Such an output stall angle reduces noise and increases the efficiency of the fan at total pressures of less than 150 Pa.

Advantageously, at least one blade may be curved so that said fan may be a reaction fan. In other words, the blade moves away from the center of the fan in the opposite direction to the direction of rotation of the fan.

In this case, the angle of entry angle, respectively output, is formed by: - the input radius, respectively output, and - the tangent to the circle passing through said blade, at the edge of entry, respectively of output.

Alternatively, at least one blade may be rectilinear.

In this case, the angle of entry angle, respectively output, is formed by: - the input radius, respectively output, and - the line passing through said blade.

In particular, the input radius of at least one blade may be between: - on the one hand 60 mm, more particularly 80 mm, even more particularly 90 mm, and - on the other hand 180 mm, more particularly 130 mm, still more particularly 110 mm.

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

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

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

Preferably, the exit radius of at least one blade may 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 output radius of at least one blade may be equal to 209 mm.

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

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

In one embodiment of the fan according to the invention, the angle of entry angle 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 °.

In particular, the angle of entry angle of at least one blade may be equal to 70 ° and more particularly equal to 69 °.

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

In one embodiment of the fan according to the invention, the stall angle at the exit of at least one blade may be between: on the one hand 60 °, more particularly 64 °, still more particularly 67 °, and on the other hand 180 °, more particularly 130 °, more particularly 110 °.

In particular, the wedging angle at the outlet of at least one blade may be equal to 70 ° and more particularly equal to 76 °.

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

Advantageously, the fan according to the invention may 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 input edge side may be between 60 mm and 180 mm.

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

Furthermore, the height of at least one blade on the side of the input edge 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 output edge side may be between 60 mm and 180 mm.

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

In addition, the height of at least one blade on the output 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.

In particular, the diameter of the suction inlet may be between: on the one hand 200 mm, more particularly 260 mm, even more particularly 310 mm, and on the other hand 340 mm, more particularly 360 mm, still more particularly 400 mm.

In an advantageous version of 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 may be assembled by welding, screwing or other means of attachment.

Advantageously, all the blades may be identical.

Alternatively, at least two vanes may have different dimensions, such as input radii, output radii, wedging angles, and so on. different.

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

Furthermore, the extraction rate of the fan according to the invention may be less than 2000 m3 / h.

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

This form of at least one blade makes it possible to increase the efficiency of the fan according to the invention for extracting air at a flow rate of between 1500 m3 / h and 2000 m3 / h.

According to another aspect of the invention, there is provided a device for extracting air at a total pressure of less than 150 Pa, comprising: at least one fan according to the invention, at least one motor provided for rotate said at least one fan.

According to another aspect of the invention, there is provided a ventilation device provided for extracting air at a total pressure of 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 with respect to said fan, characterized in that that the radial outlet opening is located opposite said fan and extends around said fan, 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 lower than 150 Pa ° and to reduce the noise of the ventilation device.

FIG. 1 is a schematic representation of an example non-limiting embodiment of a fan according to the invention; FIGURE 2 is a top view of the fan of FIGURE 1; - FIGURE 3 is a side view of an exemplary limiting embodiment of a blade of a fan according to the invention; FIG. 4 is a schematic representation of a nonlimiting example of a device according to the invention; and FIGURES 5a and 5b are diagrammatic representations of a nonlimiting example of a ventilation device according to the invention.

It is understood that the embodiments which will be described in the following are in no way limiting. It will be possible, in particular, 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 with respect to the state of the art. This selection comprises at least one feature preferably functional without structural detail, or with only a part of the structural details if this part alone is sufficient to confer a technical advantage or to differentiate the invention from the state of the prior art.

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, said lower, and a flange 104, said upper. The upper flange 104 comprises a circular opening, said suction louvre 106, provided for the passage of air.

The fan 100 also comprises 7 blades 108 bent in a direction opposite to the rotation of the fan 100. Each blade 108 is defined by an inlet edge 110i located towards the center of the fan 100 and an exit edge IIO2 located on the periphery of the fan. 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.

FIGURE 2 is a top view of the fan of FIGURE 1.

In FIG. 2, the upper flange 104 has been omitted for clarity and to allow visual access to the blades 108.

The fan 100 comprises a radius 202i, said input, corresponding to the radius of the circle 204i passing through the input edges 110i of all the blades 108. The input radius 202i is between 90 mm and 130 mm, in particular equal to 113 mm.

The fan 100 comprises a radius 2022, said output, corresponding to the radius of the circle 2042 passing through the output edges IIO2 of all the blades 108. The output radius 2022 is between 150 mm and 250 mm, in particular equal to 209 mm.

The fan 100 comprises, for each blade 108, an angle 206i, called the angle of entry angle, formed by firstly the input radius 202i and secondly the tangent 208i to said blade 108 at its edge llOi entrance. For each blade 108, the entry angle angle 206i is between 60 ° and 75 °, in particular 70 °.

The fan 100 comprises, for each blade 108, an angle 2062, called the angle of exit, formed on the one hand the output radius 2022 and on the other hand the tangent 2082 to said blade 108 at its edge. output IIO2. For each blade 108, the stall angle output 20Ô2 is between 60 ° and 85 °, in particular equal to 70 °.

In addition, the fan 100 comprises a fixing means 210 provided for connecting said fan 100 to a motor not shown in FIG. 2. The fastening means 210 may comprise an opening for fixing a transmission shaft and mounting holes. screw passage provided for fixing said transmission shaft to the fan 100.

FIGURE 3 is a side view of an exemplary non-limiting embodiment of a blade of a fan according to the invention. The blade 300, shown in FIG. 3, can be a blade 108 of the fan 100. The blade 300 is defined by an inlet edge 302i situated towards the center of a fan comprising it and an outlet edge 3022 situated at the periphery of said fan. The blade 300 has a height 3042 at its output edge 3022 which decreases to a height 304i towards the input edge 302i along the length of the blade 300. The blade 300 is therefore beveled .

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

The height 3042 between 60 mm and 180 mm, in particular equal to 100 mm.

Alternatively to what is shown in FIGURE 3, the height 304i may be equal to the height 3042 so that the height of the blade remains constant throughout its 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 may be made of metal or metal alloy, for example steel, aluminum, or polymers, for example polypropene. The blade 300 can be made by machining or foundry.

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

Device 400 is provided for extracting air at total pressures of less than 150 Pa. Device 400 includes fan 100 of 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 designed to drive the rotation of the fan 100, in particular at a speed of between 300 rpm and 900 rpm. .

The device 400 can be arranged in an air extraction installation of an apartment building, for example.

FIGURES 5a and 5b are diagrammatic representations of a nonlimiting example of a ventilation device according to the invention.

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

The ventilation device 500 comprises the fan 100 of FIGURES 1 and 2 arranged in a structure 502. The structure 502 comprises an air inlet opening 504 provided for the passage of air for its extraction by the fan 100. The device 500 comprises a stitching 506 provided for connecting the air inlet opening 504 to a ventilation duct, for example 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 provided to drive the rotation of the fan 100, in particular at a speed of between 300 rpm. / min and 900 rpm.

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

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

Of course, the invention is not limited to the examples that have just been described and many adjustments can be made to these examples without departing from the scope of the invention.

Claims (14)

Centrifugal fan (100), designed for extracting air at a total pressure of less than 150 Pa, comprising: - a flange (102), said lower, of circular shape and a flange (104), said upper, and - at least one blade (108; 300) arranged between said flanges (102; 104) and comprising an edge (110i; 302i), said inlet, located towards the center of said fan (100), and an edge (1102 3022), said output, located at the periphery of said fan (100); characterized in that for at least one blade (108; 300): - a radius (202i), said input, defined between the center of said fan (100) and the input edge (110i; 302i) of said blade (108; 300), is between 90 mm and 130 mm, and - a radius (2022), said output, defined between the center of said fan (100) and the output edge (1102; 3022) of said blade ( 108; 300) is between 150 mm and 250 mm; and in that for at least one blade (108; 300), an angle (2Ο62), called the angle of exit angle, formed by: - the exit radius (2022), and - the tangent (2082) at said dawn (108; 300) at the output edge (1102; 3022) is between 64 ° and 85 °. 2. Fan (100) according to the preceding claim, characterized in that, for at least one blade (108; 300), an angle (206i), said angle of entry, formed by: - the input radius ( 202i), and - the tangent (208i) at said blade (108; 300) at the input edge (110i; 302i) is between 60 ° and 75 °. 3. Fan (100) according to any one of the preceding claims, characterized in that at least one blade (108; 300) is curved, so that said fan (100) is a reaction fan. 4. Fan (100) according to any one of the preceding claims, characterized in that the input radius (202i) of at least one blade (108; 300) is between: - on the one hand 90 mm, and - on the other hand 130 mm, even more particularly 110 mm. 5. Fan (100) according to any one of the preceding claims, characterized in that the output radius (202i) of at least one blade (108; 300) is between: on the one hand 150 mm, particularly 170 mm, more particularly 180 mm, even more particularly 200 mm, and - secondly 250 mm, particularly 230 mm, more particularly 220 mm, more particularly 212 mm. 6. Fan (100) according to any one of claims 2 to 5, characterized in that the inlet wedging angle (206i) of at least one blade (108; 300) is between: - a 60 °, more particularly 65 °, and - on the other hand 75 °, more particularly 73 °. 7. Fan (100) according to any one of the preceding claims, characterized in that the wedging angle at the outlet (2062) of at least one blade (108; 300) is between: - on the one hand 64 °, still more particularly 67 °, and - on the other hand 85 °. 8. Fan (100) according to any one of the preceding claims, characterized in that it comprises a number of blades (108, 300) odd between 5 and 11, in particular equal to 7. 9. Fan (100) according to any one of the preceding claims, characterized in that the height (304i) of at least one blade (108; 300) on the input edge side (110i; 302i) is between 60 mm and 180 mm. 10. Fan (100) according to any one of the preceding claims, characterized in that the height (3042) of at least one blade (108; 300) on the output edge side (1102; 3022) is between 60 mm and 180 mm. 11. Fan (100) according to any one of the preceding claims, characterized in that the upper flange comprises an opening (106), called a suction inlet, provided for the passage of air in a direction substantially perpendicular to said flange upper (104), said suction port (106) being circular in shape and having a diameter of between 200 mm and 400 mm, in particular equal to 315 mm. 12. Fan (100) according to any one of the preceding claims, characterized in that its rotational speed is between 300 rpm and 900 rpm. 13. 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) arranged to rotate said at least one fan (100). 14. Ventilation device (500) designed for the extraction of air at a total pressure of less than 150 Pa, comprising at least one fan (100) according to any one of claims 1 to 12, arranged in a structure (502 ), said structure (502) comprising for at least one fan (100): - an inlet opening (504) of air towards the fan (100), arranged axially with respect to said fan (100), - an opening of outlet (508) of air, from the fan (100), arranged radially relative 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).