Flow grid for a ventilation device and ventilation device

Abstract

The invention relates to a flow grille (100, 100') for attachment to a fan housing of a ventilation device, comprising: an outer centric guide vane (140) defining an outer edge of the flow grille, a plurality of radial guide vanes (160) extending at least partially radially toward a central region (130) of the flow grille, and a plurality of inner centric guide vanes (170) extending at least partially centrally around a center point of the flow grille, wherein the flow grille has an outer contour, wherein at least some of the radial guide vanes and / or the inner centric guide vanes define the outer contour of the flow grille, wherein the flow grille has an outer region (120) surrounding the central region of the flow grille, wherein the outer contour is convex in the outer region of the flow grille,wherein the outer contour is concave in the central region of the flow grille, and wherein at least one of the plurality of inner centric guide vanes is interrupted in at least a first section. This enables an increase in the efficiency of the ventilation unit while simultaneously reducing the sound power level.

Description

[0001] The present invention relates to the field of ventilation devices and, in particular, to a flow grille for use in a ventilation device.

[0002] Ventilation units are increasingly being used in private homes. This requires continuous optimization of ventilation systems, particularly by increasing their efficiency and minimizing sound power levels.

[0003] The sound power level, or noise level, of a ventilation unit depends significantly on the airflow through the unit. This begins at the air inlet, where the inlet is usually covered by a flow grille.

[0004] Here, it is desired to improve the flow behavior of the air to the impeller (fan) through the geometry of the flow grille in order to increase the efficiency of the fan or ventilation unit and at the same time reduce the sound power level.

[0005] An object underlying the present invention is to improve an electrical efficiency of the ventilation device and / or to reduce a sound power level without impairing or even improving the electrical efficiency of the ventilation device.

[0006] It is therefore desired to present a solution that addresses the above problems.

[0007] According to a first aspect of the invention, a flow grille is proposed as defined in claim 1, namely a flow grille for attachment to a fan housing of a ventilation device, comprising: (i) an outer centric guide vane defining an outer edge of the flow grille, (ii) a plurality of radial guide vanes extending at least partially radially toward a central region of the flow grille, and (iii) a plurality of inner centric guide vanes extending at least partially centrally around a center point of the flow grille, wherein the flow grille has an outer contour, wherein at least some of the radial guide vanes and / or the inner centric guide vanes define the outer contour of the flow grille, wherein the flow grille has an outer region surrounding the central region of the flow grille, wherein the outer contour is convex in the outer region of the flow grille,wherein the outer contour is concave in the central region of the flow grid and wherein at least one of the plurality of inner centric guide vanes is interrupted at least in a first partial section.,

[0008] The flow grille according to the invention enables an increase in the electrical efficiency of the ventilation unit and a simultaneous reduction in the sound power level of the ventilation unit.

[0009] The flow grille is designed and configured for attachment to a fan housing of a ventilation unit. In particular, the flow grille is designed and configured for attachment to a differential pressure nozzle, which can be considered part of a fan housing.

[0010] The flow cascade comprises an outer centric guide vane that defines an outer edge of the flow cascade. The outer edge can also be defined by other features of the flow cascade, for example by edges of openings, by a recess (see below), etc., as long as the outer edge is primarily defined by the outer centric guide vane. The outer centric guide vane has the largest radius compared to all other (inner) centric guide vanes. The outer centric guide vane is essentially circular and surrounds all other inner centric guide vanes. Preferably, the outer centric guide vane is continuous, i.e., uninterrupted. The outer centric guide vane runs centrically around a center point of the flow cascade.

[0011] The flow grid further comprises a plurality of radial guide vanes that extend at least partially radially toward a central region of the flow grid. "At least partially radial" here means that a radial guide vane does not necessarily extend from the outer edge into the central region, but possibly only over a partial section located between the outer edge and the central region. In particular, "at least partially radial" includes radial guide vanes that extend from the outer edge to a point in the outer region, radial guide vanes that extend from the outer edge to a point in the central region, radial guide vanes that extend from a point in the outer region to a point in the central region, etc. In particular, opposing radial guide vanes can meet at a center point of the flow grid.Preferably, the radial guide vanes run towards a center point of the central area or the flow grid.

[0012] Furthermore, the flow grid comprises a plurality of inner centric guide vanes, which extend at least partially centrically around a center point of the flow grid. The plurality of inner centric guide vanes are located within the outer centric guide vane. Furthermore, the center point of the flow grid is arranged in the central region of the flow grid; preferably, the center point of the flow grid corresponds to a center point of the central region.

[0013] The flow grille has an outer contour, which can also be understood as a profile of the flow grille, i.e., a profile along a flow direction of air through the flow grille, in particular, opposite to the flow direction, and is described further below. This means that, when the flow grille is used properly, the outer contour is directed outward, i.e., away from the impeller or the ventilation unit.

[0014] The outer contour is defined by at least some of the radial guide vanes and / or the inner centric guide vanes. This means that an extension of the flow grid opposite to a flow direction of air through the flow grid is defined by the plurality of radial guide vanes and / or the plurality of inner centric guide vanes. The radial guide vanes can also be understood as tangential guide vanes. Particularly preferably, the outer contour of the flow grid is defined by all of the radial guide vanes and / or the inner centric guide vanes.

[0015] The airflow grille has an outer region surrounding the central region of the airflow grille. In particular, the outer region and the central region correspond to regions of the airflow grille, as seen from a front side of the airflow grille when properly attached to the fan housing of the ventilation unit. The airflow grille is essentially circular, with the central region being understood as essentially circular and the outer region as a circular ring.

[0016] The outer contour in the outer region of the flow grid is convex, while the outer contour in the central region of the flow grid is concave. The outer contour of the flow grid is preferably continuous, i.e., it has no edges.

[0017] The flow grid according to the invention is characterized in particular by the fact that at least one of the plurality of inner centric guide vanes is interrupted at least in a first partial section. "Interrupted" means that the at least one of the plurality of inner centric guide vanes does not extend over its entire circumference, but rather partially, centrally around the center point. In particular, an inner centric guide vane that extends partially centrally around the center point can consist of several parts, for example, two parts.

[0018] A subsection, for example, the first subsection, can correspond to a subsection of the outer region, a subsection of the central region, or a subsection of the outer region and a subsection of the central region. In a case where the subsection corresponds to a subsection of the outer region and the outer region is described as a circular ring, the subsection can be understood as a subsection of the circular ring.

[0019] It is preferred that two or three of the plurality of inner centric guide vanes are interrupted at least in a first partial section. It is further preferred that at least one of the plurality of inner centric guide vanes extends through the first partial section.

[0020] In an advantageous embodiment of one aspect of the invention, at least one of the plurality of inner centric guide vanes is interrupted in a second subsection opposite the first subsection. This means that at least one of the plurality of inner centric guide vanes is interrupted at two points, i.e., in the first subsection and in the second subsection. "Opposite each other" means that the first subsection and the second subsection lie on a straight line that runs through the center of the flow grid.

[0021] In particular, it is preferred that two or three of the plurality of inner centric guide vanes are interrupted in a second section opposite the first section. It is further preferred that at least one of the plurality of inner centric guide vanes extends through the first section and the second section.

[0022] In another advantageous embodiment of an aspect of the invention, at least one of the plurality of radial guide vanes is provided with a pre-swirl. "Provided with a pre-swirl" means that the at least one of the plurality of radial guide vanes generates a pre-swirl, e.g., through a curved surface (curvature), an angle oblique to the direction of air flow through the flow grille (tilt), etc. Preferably, at least three, particularly preferably at least five, of the plurality of radial guide vanes are provided with a pre-swirl.

[0023] In a preferred variant of the above embodiment, the at least one of the plurality of radial guide vanes provided with the pre-swirl is arranged in a third subsection located between the first subsection and a second subsection opposite the first subsection. Preferably, at least three, particularly preferably at least five, of the plurality of radial guide vanes in the third subsection are provided with the pre-swirl.

[0024] The above variant can further be configured such that at least one further one of the plurality of radial guide vanes is provided with a pre-swirl, wherein the at least one further one of the plurality of radial guide vanes provided with the pre-swirl is arranged in a fourth sub-section opposite the third sub-section, which is arranged between the first sub-section and the second sub-section opposite the first sub-section. Preferably, at least three, particularly preferably five, of the plurality of radial guide vanes in the fourth sub-section are provided with the pre-swirl.

[0025] It is particularly preferred that each of the subsections, i.e. the first subsection, the second subsection, the third subsection and the fourth subsection, is substantially a subsection of a circular ring. Preferably, the third subsection and the fourth subsection are each larger than the first subsection and the second subsection, wherein more preferably the third subsection is substantially the same size as the fourth subsection and the first subsection is substantially the same size as the second subsection. In particular in the case in which the outer region is described by a circular ring, in a preferred embodiment the first subsection and the second subsection correspond substantially to one sixth of the circular ring and the third subsection and the fourth subsection each correspond to one third of the circular ring.

[0026] In a further preferred variant of the above embodiment, the pre-swirl is 8° to 12°, particularly preferably 10°, wherein the pre-swirl is further preferably provided by a curvature of the radial guide vanes of 8 to 12°, particularly preferably 10°. In addition, the pre-swirl is preferably provided on the radial guide vanes counter to a direction of rotation of a fan of the ventilation device.

[0027] It should be noted that in a case where a pre-swirl is provided, the pre-swirl is preferably provided over an entire length of the corresponding radial guide vane.

[0028] In another advantageous embodiment of an aspect of the invention, at least some, preferably all, of the radial guide vanes abut the outer central guide vane.

[0029] In a further advantageous embodiment of an aspect of the invention, the flow grid is designed as a flow straightener.

[0030] In another advantageous embodiment of an aspect of the invention, the flow grille has a fastening means for attachment to the ventilation unit. The fastening means is preferably provided on the outer central guide vane and can in particular be part of the outer central guide vane. The fastening means preferably comprises openings. Particularly preferably, the fastening means comprises four openings for fastening, in particular for screwing, the flow grille to the fan housing or the differential pressure nozzle of the ventilation unit.

[0031] According to a further aspect of the invention, a ventilation device is proposed as defined in claim 10, namely a ventilation device with a differential pressure nozzle, wherein the ventilation device comprises a flow grille according to one of the above or below embodiments. The flow grille is arranged on a suction side of the ventilation device, in particular fastened, e.g., via the fastening means as described above. Particularly preferably, the flow grille is arranged on the differential pressure nozzle, in particular fastened, e.g., screwed.

[0032] In a preferred embodiment, the differential pressure nozzle comprises a measuring tube, wherein the flow grid then has a recess for attachment to the differential pressure nozzle or for at least partially accommodating the measuring tube. When the flow grid and the differential pressure nozzle are assembled, the measuring tube is then at least partially arranged in the recess.

[0033] The flow grid is preferably made of plastic, particularly preferably by an injection molding process.

[0034] Features of advantageous embodiments of the invention are defined in particular in the subclaims, wherein further advantageous features, embodiments and configurations can also be gathered from the above explanation and the following discussion by the person skilled in the art.

[0035] In the following, the present invention is further illustrated and explained with reference to exemplary embodiments shown in the figures. Fig. 1 is a schematic representation to illustrate a first embodiment of the ventilation device according to the invention, Fig. 2 is a schematic representation to illustrate a first embodiment of the flow grille according to the invention in cross section, Fig. 3 is a schematic representation to illustrate the first embodiment of the flow grille according to the invention from the front, Fig. 4 is a schematic representation to illustrate a second embodiment of the flow grille according to the invention from the front, Fig. 5 is a schematic representation to illustrate a pre-swirl of the radial guide vanes of the second embodiment of the flow grille according to the invention, Fig. 6 is a schematic representation to illustrate a recess of the first or second embodiment of the flow grille according to the invention, Fig.Fig. 7 is a perspective view illustrating the second embodiment of the flow grid according to the invention, viewed obliquely from the front, and Fig. 8 is a further perspective view illustrating the second embodiment of the flow grid according to the invention, viewed obliquely from the rear.

[0036] In the accompanying drawings and the explanations to these drawings, corresponding or related elements are - where appropriate - identified by corresponding or similar reference numerals, even if they are found in different embodiments.

[0037] Fig. 1 shows a schematic representation to illustrate a first embodiment of the ventilation device according to the invention.

[0038] The ventilation device 200 comprises a fan housing 210 and a flow grille 100. The ventilation device 200 also comprises a fan (not shown) which is Fig. 1 is arranged behind the flow grille 100. The ventilation unit 200 further comprises a differential pressure nozzle 220, which can be counted as part of the fan housing 210. A measuring tube 230 is arranged on the differential pressure nozzle 220.

[0039] The flow grille 100 is designed and configured for attachment to the fan housing 210. The flow grille 100 includes four openings 110 through which the flow grille 100 can be attached to the differential pressure nozzle 210 or the fan housing 210.

[0040] The flow grid 100 is described in further detail using the following figures.

[0041] Fig. 2 shows a schematic representation to illustrate a first embodiment of the flow grid according to the invention in cross section.

[0042] Here, the outer contour of the flow grid 100 can be seen. The outer contour is defined by at least some of the radial guide vanes 160 and / or the inner centric guide vanes 170 of the flow grid.

[0043] The flow grid 100 has an outer region 120 and a central region 130, wherein the outer region 120 surrounds the central region 130.

[0044] The outer contour in the outer region 120 of the flow grid 100 is convex, while the outer contour in the central region 130 of the flow grid 100 is concave.

[0045] Fig. 3 shows a schematic representation to illustrate the first embodiment of the flow grid according to the invention from the front.

[0046] The flow grid 100 has an outer centric guide vane 140 that defines an outer edge of the flow grid 100. The outer edge is further defined by edges of the openings 110 (which can also be understood as part of the outer centric guide vane 140) and the recess 150.

[0047] From this perspective, i.e., from the front, the flow grid 100 is essentially round. In particular, the central region 130 is also essentially round, with the outer region 120 being essentially described by a circular ring.

[0048] The flow grid 100 has a plurality of radial guide vanes 160, which extend at least partially radially toward the central region 130 of the flow grid 100. Furthermore, the flow grid 100 has a plurality of inner centric guide vanes 170, which extend at least partially centrally around a center point of the flow grid 100. At least one, in this case three, of the plurality of inner centric guide vanes 170 is interrupted at least in a first partial section, which corresponds to a partial section of the outer region and the central region 130. In the present case, four radial guide vanes 160 meet at a center point of the central region 130 or of the flow grid 100.

[0049] The flow grid 100 can be divided into twelve sections, similar to a clock. The 12 o'clock position corresponds to one-twelfth of the flow grid 100 or the outer region 120 and / or the central region 130, which, when used as intended, is directed upwards; the 3 o'clock position corresponds to one-twelfth of the flow grid 100, which is directed to the right, etc.

[0050] According to this definition, the first sub-section corresponds to the 3 o'clock position and one half each of the 2 o'clock position and the 4 o'clock position. The second sub-section then corresponds to the 9 o'clock position and one half each of the 8 o'clock position and the 10 o'clock position. The third sub-section also corresponds to the 11 o'clock position, the 12 o'clock position, the 1 o'clock position and the other half each of the 2 o'clock position and the 10 o'clock position. The fourth sub-section then corresponds to the 5 o'clock position, the 6 o'clock position, the 7 o'clock position and the other half each of the 4 o'clock position and the 8 o'clock position. The first sub-section can also be swapped with the second sub-section, as can the third sub-section with the fourth sub-section, i.e. the names of the sub-sections are simply chosen for differentiation.

[0051] Fig. 4 shows a schematic diagram illustrating a second embodiment of the flow grid according to the invention from the front. In this context, a description of the features described in connection with the first embodiment is omitted. Furthermore, some of the description of the features described in connection with the second embodiment also applies to the first embodiment.

[0052] In the flow grille 100', in particular, a pre-swirl of some of the plurality of radial guide vanes 160' is provided, preferably by a curvature of 8° to 12°, particularly preferably of 10°, counter to a direction of rotation of a fan of the ventilation device 200.

[0053] Fig. 5 shows a schematic representation to illustrate a pre-swirl of the radial guide vanes of the second embodiment of the flow grid according to the invention.

[0054] In particular, it can be seen that the pre-swirl is generated by a curvature of the radial guide vanes 160'.

[0055] Fig. 6 shows a schematic representation to illustrate a recess of the first or second embodiment of the flow grid according to the invention.

[0056] The recess 150 is intended to accommodate a measuring tube 230 of the differential pressure nozzle 220.

[0057] Fig. 7 shows a perspective view to illustrate the second embodiment of the flow grid according to the invention from an angle from the front and Fig. 8 shows a further perspective view to illustrate the second embodiment of the flow grid according to the invention from an angle from behind.

[0058] Here, the arrangement and shape of the radial guide vanes 160', the outer centric guide vane 140', and the inner centric guide vanes 170' can be seen in particular. It can also be seen that the outer contour of the flow cascade 100' is defined by the radial guide vanes 160'. Therefore, the radial guide vanes 160' can also be understood as tangential guide vanes.

[0059] Further considerations regarding the invention follow: A separate flow grid for a ventilation unit is proposed, which is preferably made of plastic and more preferably manufactured by injection molding. The ventilation unit preferably comprises a fan arranged in a spiral casing and a differential pressure nozzle. The flow grid, also called a flow grid, is preferably mounted on the suction side of the fan. In a preferred embodiment, the flow grid is screwed to the front part of the spiral casing at designated fastening points located on the differential pressure nozzle of the ventilation unit.

[0060] The flow grille is preferably a flow straightener, which has the task of breaking the vortices of the air being sucked in in the nozzle area and of distributing the air entering the ventilation unit or fan evenly over the blades of the fan.

[0061] The use of the airflow grille significantly improves the airflow pattern toward the fan. This increases the fan's electrical efficiency at the same flow rate, thus reducing power consumption. At the same time, the improved airflow into the fan, which is due to the airflow grille, also reduces the sound power level. In our case, at the ventilation unit's maximum airflow, the sound power level was reduced by approximately 6 dB compared to measurements without the airflow grille.

[0062] Preferably, four tangents are created along the outer convex contour of the flow cascade at a tangential radius. The central region is designed to be concave over a radius, see the following figure: Simulations have shown that the flow cascade can be optimized for this application by removing, i.e., interrupting, centric guide vanes.

[0063] By eliminating the centric guide vanes, pressure loss is reduced, resulting in better electrical efficiency of the fan.

[0064] It has been found to be particularly advantageous to remove at least some of the centric guide vanes at the 3 o'clock position and at the 9 o'clock position of the flow grid (see above).

[0065] In one variant, all centric guide vanes at the 3 o'clock position and at the 9 o'clock position of the flow grid can be removed, but for strength reasons it may be advantageous to provide at least one centric guide vane at the 3 o'clock position and the 9 o'clock position.

[0066] Furthermore, it is preferred that the centric guide vanes are provided at the 12 o'clock position and the 6 o'clock position so that the existing air vortices are broken.

[0067] In order to (almost) dissolve the air vortices at the 12 o'clock position and the 6 o'clock position, the tangential guide vanes at the 12 o'clock position and the 6 o'clock position can be provided with a pre-swirl by a curvature of 8° to 12°, particularly preferably 10°, wherein the pre-swirl is further preferably applied to the tangential guide vanes opposite to the direction of rotation of the fan.

[0068] Preferably, the flow grille has a fastening concept such that it fits into the provided recess of the differential pressure nozzle via a type of sleeve. In one example, the flow grille is screwed to a front part of the spiral casing using four screws.

[0069] An additional recess on the flow grid is preferably provided in order to join it to the differential pressure nozzle in the area of a measuring tube.

[0070] The following preferred features can be provided alone or in combination: outer contour (of the outer area) consisting of several tangents that are adjacent to a radius, central area concavely curved, centric guide vanes were removed at the 3 o'clock position and the 9 o'clock position, fastening concept through openings (sleeves and screws), tangential guide vanes can be provided with a pre-swirl against the direction of rotation of the fan at certain positions in order to break stronger vortices more easily, especially at the 12 o'clock position and the 6 o'clock position.

[0071] The following advantages can be achieved by using some or all of the above features: Eliminating the centric guide vanes at the 3 o'clock position and the 9 o'clock position results in better flow distribution and less pressure loss due to omitted centric guide vanes.

[0072] Providing the tangential guide vanes with a pre-swirl in certain areas can break up vortices more efficiently.

[0073] The invention relates to a flow grille for attachment to a fan housing of a ventilation device, comprising: an outer centric guide vane defining an outer edge of the flow grille, a plurality of radial guide vanes extending at least partially radially toward a central region of the flow grille, and a plurality of inner centric guide vanes extending at least partially centrally around a center point of the flow grille, wherein the flow grille has an outer contour, wherein at least some of the radial guide vanes and / or the inner centric guide vanes define the outer contour of the flow grille, wherein the flow grille has an outer region surrounding the central region of the flow grille, wherein the outer contour is convex in the outer region of the flow grille,wherein the outer contour is concave in the central region of the flow grid and wherein at least one of the plurality of inner centric guide vanes is interrupted at least in a first partial section.,

Claims

1. A flow grille (100, 100') for attachment to a fan housing (210) of a ventilation device (200), comprising: an outer centric guide vane (140) defining an outer edge of the flow grille (100, 100'), a plurality of radial guide vanes (160) extending at least partially radially toward a central region (130) of the flow grille (100, 100'), and a plurality of inner centric guide vanes (170) extending at least partially centrically around a center point of the flow grille (100, 100'), wherein the flow grille (100, 100') has an outer contour, wherein at least some of the radial guide vanes (160) and / or the inner centric guide vanes (170) define the outer contour of the flow grille (100, 100'), wherein the Flow grid (100, 100') has an outer region (120) surrounding the central region (130) of the flow grid (100, 100'),wherein the outer contour in the outer region (120) of the flow grid (100, 100') is convex, wherein the outer contour in the central region (130) of the flow grid (100, 100') is concave, and wherein at least one of the plurality of inner centric guide vanes (170) is interrupted at least in a first partial section of the flow grid.

2. Flow grid (100, 100') according to claim 1, wherein the at least one of the plurality of inner centric guide vanes (170) is interrupted in a second section opposite the first section.

3. Flow grid (100, 100') according to one of claims 1 and 2, wherein at least one of the plurality of radial guide vanes (160) is provided with a pre-swirl.

4. Flow grid (100, 100') according to claim 3, wherein the at least one of the plurality of radial guide vanes (160) provided with the pre-swirl is arranged in a third sub-section which is arranged between the first sub-section and a second sub-section opposite the first sub-section, wherein preferably two to five of the plurality of radial guide vanes (160) in the third sub-section are provided with the pre-swirl.

5. Flow grid (100, 100') according to claim 4, wherein at least one further one of the plurality of radial guide vanes (160) is provided with a pre-swirl, wherein the at least one further one of the plurality of radial guide vanes (160) which is provided with the pre-swirl is arranged in a fourth sub-section opposite the third sub-section, which is arranged between the first sub-section and the second sub-section opposite the first sub-section, wherein preferably two to five of the plurality of radial guide vanes (160) in the fourth sub-section are provided with the pre-swirl.

6. Flow grid (100, 100') according to one of claims 3 to 5, wherein the pre-swirl is provided by a curvature of the radial guide vanes (160) of 8° to 12°, preferably 10°, and particularly preferably is provided counter to a direction of rotation of a fan of the ventilation device (200).

7. Flow grid (100, 100') according to one of the preceding claims, wherein at least some, preferably all, of the radial guide vanes (160) abut the outer central guide vane (140).

8. Flow grid (100, 100') according to one of the preceding claims, wherein the flow grid (100, 100') is designed as a flow straightener.

9. Flow grille (100, 100') according to one of the preceding claims, wherein the flow grille (100, 100') has a fastening means (110) for fastening to the ventilation device (200), wherein the fastening means (110) preferably comprises openings, particularly preferably four openings.

10. Ventilation device (200) with a differential pressure nozzle (220), wherein the ventilation device (200) comprises a flow grille (100, 100') according to one of claims 1 to 9, wherein the flow grille (100, 100') is arranged, in particular fastened, on a suction side of the ventilation device (200), wherein the flow grille (100, 100') is preferably arranged, in particular fastened, on the differential pressure nozzle (220).

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