Flow guide device and fan arrangement with a flow guide device

Abstract

The invention relates to a flow guide device for use on a blower arrangement with a motor-driven radial blower wheel rotating about an axis of rotation, comprising an outer housing and an inner diffuser between which a flow channel extending along an axial flow direction is formed, the outer housing forming a receiving space adjacent to the inner diffuser in the axial direction for the integral reception of the radial blower wheel, which in operation draws in a flow axially and blows out radially into the flow channel, wherein the flow channel is designed to redirect the flow from a radial to an axial direction.

Description

[0001] The invention relates to a flow guide device for use on a blower arrangement with a motor-driven radial blower wheel and the blower arrangement with a corresponding flow guide device.

[0002] Influencing the flow generated by a radial fan after it exits the radial fan wheel via a flow guide device according to the invention enables an increase in static efficiency. This is particularly advantageous when the radial flow is to be redirected into an axial flow and, for example, a downstream component such as a heat exchanger is to be supplied with a homogeneous axial outflow field.

[0003] On the intake side, a split nozzle has already proven advantageous, as described in German patent application DE 10 2017 110 642 A1. Further prior art in this field is disclosed in documents US 2018 / 283401 A1, WO 2018 / 113855 A1, EP 3 141 757 A1, FR 2 922 610 A1 and EP 3 354 903 A1.

[0004] The invention is based on the objective of providing a flow guidance device with which the static efficiency of blower arrangements with a radial blower wheel, in which the radially blown flow is subsequently deflected axially, is to be increased.

[0005] This problem is solved by the combination of features according to claim 1.

[0006] According to the invention, a flow guide device for use on a blower assembly with a motor-driven radial impeller rotating about an axis of rotation is proposed. The device comprises an outer housing and an inner diffuser, between which a flow channel extending along an axial flow direction is formed. The outer housing forms a receiving space adjacent to the inner diffuser in the axial direction for the integral reception of the radial impeller, which, during operation, draws in a flow axially and blows it radially into the flow channel. The flow channel is designed to redirect the flow from a radial to an axial direction. The axial flow direction is parallel to the axis of rotation of the radial impeller. The inner diffuser and the outer housing are preferably cylindrical or substantially cylindrical and arranged coaxially to each other.

[0007] The flow channel, formed downstream in the direction of flow via the outer casing and the inner diffuser, converts the dynamic pressure energy into static pressure energy in the flow, thus solving the problem.

[0008] In a favorable design of the flow guide device, the flow channel extends to its outlet. Thus, the flow is guided over the entire length of the flow guide device.

[0009] Furthermore, the conversion of dynamic pressure energy into static pressure energy in the flow guide device is facilitated by the fact that the cross-sectional area of ​​the flow channel increases diffuser-like towards the outlet. This is achieved, for example, by having the inner diffuser taper towards the outlet, i.e., its surface area extends along the axial path to the outlet, towards the axis of rotation of the radial fan wheel.

[0010] In one embodiment, the flow guide device is further characterized in that the receiving space for the radial fan wheel adjoins an inlet of the flow guide device.

[0011] To reduce noise, the flow guide device according to the invention is provided that the inner diffuser has a perforated outer surface. Similarly, an embodiment of the flow guide device is characterized in that the outer housing has a perforated inner wall surface. The flow can pass completely or partially through the perforations of the outer surface of the inner diffuser or through the inner wall surface of the outer housing, thereby reducing acoustic sound radiation. In addition, insulating materials can optionally be incorporated, for example, inside the inner diffuser or in parts of the perforations.

[0012] A further development of the flow guide device to further increase the static efficiency also provides for the arrangement of flow guide vanes spaced at circumferential intervals within the flow channel. In an advantageous embodiment, the flow guide vanes preferably extend from the area of ​​the receiving chamber for the radial fan wheel to the outlet and provide guidance for the flow from the discharge of the radial fan wheel to the outlet of the flow guide device. The increase in static efficiency is promoted by the reduction of swirl in the flow caused by the flow guide vanes.

[0013] According to the invention, the inner diffuser also has a diffuser chamber, separated from the flow channel by its outer surface, which is formed around the axis of rotation of the radial fan wheel. Guide vanes are also provided in this diffuser chamber, extending towards the outlet. Such guide vanes are advantageous if the outer surface of the inner diffuser is not closed, but perforated according to the invention, so that the flow passes not only through the flow channel but also partially through the diffuser chamber. Furthermore, the guide vanes can simultaneously serve as stiffening ribs for the inner diffuser.

[0014] Furthermore, an advantageous design of the flow guide device is one in which the flow guide vanes are integrally formed in one piece with the inner diffuser.

[0015] In terms of compact design, a version in which a motor mount is integrated into the inner diffuser is also advantageous.

[0016] In a further development, the flow guide device also provides that the outer housing has an integral Venturi nozzle at the inlet. The radial fan wheel can thus interact with the Venturi nozzle on the outer housing and, for example, extend its cover plate axially into the Venturi nozzle to provide axial overlap.

[0017] For variable adaptability of the flow guide device, a design is advantageous in which the inner diffuser is designed as a removable insert in the outer housing. Thus, the flow channel or the receiving space for the radial fan wheel can be adapted as desired by replacing the inner diffuser.

[0018] Furthermore, a blower arrangement with a radial blower wheel and an associated electric motor is included, wherein the radial blower wheel is arranged in the receiving space of the flow guide device according to the preceding disclosure and its axially drawn-in flow is deflected into an axial flow via the flow channel.

[0019] Other advantageous embodiments of the invention are characterized in the dependent claims or are described in more detail below together with the description of the preferred embodiment of the invention with reference to the figures. The figures show: Fig. 1 a perspective view of a flow guide device in a first embodiment, Fig. 2 a side sectional view of the flow guide device made of Figure 1 , Fig. 3 an axial top view of the inlet side of the flow guide device made of Figure 1 , Fig. 4 direction from Figure 1, an axial top view of the outlet side of the flow guide device Figure 1 Fig. 5 a perspective view of a flow guide device in a second embodiment according to the invention; Fig. 6 a side sectional view of the flow guide device made of Figure 5 , Fig. 7 an axial top view of the inlet side of the flow guide device made of Figure 5 , Fig. 8 an axial top view of the outlet side of the flow guide device made of Figure 5 .

[0020] In the Figures 1-4Figure 1 shows a first embodiment of the flow guide device 1, which has a cylindrical outer housing 2 and a substantially cylindrical inner diffuser 3 arranged coaxially to the outer housing 2. The inner diffuser extends axially along the axis of rotation RA over approximately half the axial length of the outer housing 2. The outer housing 2 forms an inlet 8 for drawing in a flow via a radial fan wheel (not shown). A Venturi nozzle 11 is formed at the inlet 8. Adjoining the inlet 8 in the flow direction and axially adjacent to the inner diffuser 3, the outer housing 2 has a receiving chamber 5 for the integral reception of the radial fan wheel in such a way that it draws in the flow axially at the inlet 8 via the Venturi nozzle 11 and blows it out radially into the flow channel 4.The flow channel 4 is formed by the inner wall of the outer housing 2 and by the surface of the inner diffuser 3, and deflects the flow exiting the radial fan wheel in an axial direction. Towards the outlet 9, the inner diffuser 3 is conically tapered towards the axis of rotation RA, thus increasing the cross-sectional area of ​​the flow channel 4 in the direction of flow. Alternatively or additionally, the outer housing 2 can also widen to increase the cross-sectional area of ​​the flow channel. In another alternative embodiment, the inner diffuser 3 is not conically tapered towards the axis of rotation RA, but rather runs cylindrically, i.e., parallel to the axis of rotation. The inner diffuser 3 and the outer housing 2 terminate at the outlet 9 in the same axial plane.

[0021] Referring to Figure 2It is further indicated that a motor mount 15 for the secure attachment of an electric motor (not shown) for driving the radial fan wheel of the rotation axis is integrated into the inner diffuser 3 adjacent to the receiving chamber 5. Furthermore, the inner diffuser is multi-walled and provides a chamber 24 between the walls for receiving insulating material, which is subdivided by circumferentially distributed webs 19.

[0022] In the respective axial top views of the Figures 3 and 4 The connection plate 14 with circumferentially distributed stiffening struts 15 and the circumferentially distributed fastening tabs 12 can also be seen on the inlet 8 and the outlet 9.

[0023] The Figures 5 - 8 show an embodiment of the invention which, in addition to other features, has the same characteristics as the embodiment according to the Figures 1 - 4As a further development of the first embodiment, the outer housing 2 has a perforated inner wall surface with a plurality of openings 32. Furthermore, the outer surface of the inner diffuser 3 is also perforated with openings 31, so that a flow connection to the chamber 24 is formed. In the illustrated embodiment, the inner wall of the inner diffuser 3 is closed; however, it can alternatively also be provided with openings, so that a flow connection to the diffuser chamber 29 is established. For this purpose, guide vanes 13 are already provided in the diffuser chamber 29, which extend in the direction of the outlet 9. The guide vanes 13 simultaneously serve as stiffening ribs for the inner diffuser.

[0024] In the flow guide device 1, flow guide vanes 7 are arranged circumferentially spaced in the flow channel 4, extending from the area of ​​the receiving chamber 5 for the radial fan wheel to the outlet 9, as can be clearly seen in Fig. 6 The flow guide vanes 7 extend radially from the outer surface of the inner diffuser 3 to the inner wall surface of the outer housing 2.

[0025] As a further alternative design, for example, a perforated outer surface of the inner diffuser 3 and a perforated inner wall surface of the outer housing 2 can be used, but without the use of flow guide vanes 7. In addition, the flow guide vanes 7 can be designed according to the Figures 1-4 They can be integrated without this being explicitly shown separately.

Claims

1. A flow guiding device (1) for use on a fan assembly with a motor-operated radial impeller rotating about an axis of rotation (RA), comprising an outer housing (2) and an inner diffuser (3) between which there is formed a flow duct (4) extending along an axial flow direction, wherein the outer housing (2) forms a receiving space for the integral holding of the radial impeller, bordering in the axial direction on the inner diffuser (3), which during operation takes in a flow axially and blows it out radially into the flow duct (4), while the flow duct (4) is adapted to deflect the flow from a radial to an axial direction, wherein the inner diffuser is fashioned with multiple walls and provides a chamber (24) between the walls to contain insulating material, the chamber being subdivided by webs (19) distributed in the circumferential direction, characterized in that the inner diffuser (3) has a perforated lateral surface, wherein the inner diffuser (3) comprises a diffuser space (29) delimited toward the flow duct (4) by its lateral surface, in which guide blades (13) extend in the direction of an outlet (9) of the flow guiding device (1).

2. The flow guiding device according to claim 1, characterized in that the flow duct (4) extends continuously from the receiving space (5) to the outlet (9) of the flow guiding device (1).

3. The flow guiding device according to claim 2, characterized in that a flow cross section area of the flow duct (4) becomes larger toward the outlet (9) in the manner of a diffuser.

4. The flow guiding device according to any one of the preceding claims, characterized in that the receiving space (5) for the radial impeller borders on an inlet of the flow guiding device (1).

5. The flow guiding device according to any one of the preceding claims, characterized in that the outer housing (2) has a perforated inner wall surface.

6. The flow guiding device according to any one of the preceding claims, characterized in that flow guide blades (7) are arranged in the flow duct (4), being spaced apart in the circumferential direction.

7. The flow guiding device according to the preceding claim, characterized in that the flow guide blades (7) extend from the region of the receiving space (5) for the radial impeller up to the outlet (9).

8. The flow guiding device according to any one of the preceding claims 6 oder 7, characterized in that the flow guide blades (7) are formed integrally as a single piece with the inner diffuser (3).

9. The flow guiding device according to any one of the preceding claims, characterized in that a motor receptacle is integrated in the inner diffuser (3).

10. The flow guiding device according to any one of the preceding claims, characterized in that the outer housing (2) comprises an integral Venturi nozzle (11) at the inlet.

11. The flow guiding device according to any one of the preceding claims, characterized in that the inner diffuser (3) is designed as a removable insert in the outer housing (2).

12. The flow guiding device according to any one of the preceding claims, characterized in that the inner diffuser (3) and the outer housing (2) are designed substantially cylindrical.

13. A fan assembly having a radial impeller and an electric motor connected to it, wherein the radial impeller is arranged in the receiving space of the flow guiding device (1) according to any one of the preceding claims.

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