EP3559474A1

EP3559474A1 - Fan module and arrangement of one or more such fan modules in a flow duct

Info

Publication number: EP3559474A1
Application number: EP17828648.0A
Authority: EP
Inventors: Frieder Loercher; Matthias GOELLER; André MUELLER
Original assignee: Ziehl Abegg SE
Current assignee: Ziehl Abegg SE
Priority date: 2016-12-23
Filing date: 2017-11-30
Publication date: 2019-10-30
Also published as: DE102016226157A1; JP2020502420A; US20190353364A1; WO2018113855A1; RU2019123026A; US11371730B2; CN110100102B; JP2022169730A; CN110100102A; BR112019011516A2; JP7496859B2; RU2019123026A3; RU2753104C2

Abstract

The invention relates to a fan module comprising at least one fan (1), possibly a nozzle plate (5) and a suspension (10). Said fan module has a device on the pressure side to reduce or suppress a backflow and to even out the air flowing out, wherein the device is designed as a mechanical backflow blocker (6), which is arranged approximately centrally in the flow path and blocks part of the flow cross section. The invention further relates to an arrangement having one or more fan modules (24) in a flow duct.

Description

FAN MODULE AND ARRANGEMENT OF ONE OR MORE OF SUCH FAN MODULES IN ONE

FLOW CHANNEL

The present invention relates to a fan module and the arrangement of one or more such fan modules in a flow channel or a comparable ventilation system, the fan module on the pressure side, a device for reducing or suppressing a backflow of the outflowing air is provided.

The term "fan" is to be understood in the broadest sense, which is usually radial, diagonal or axial fans, which are arranged modularly in housings or are connected on the pressure side to flow channels which direct the air flow in a mostly axial direction Corresponding flow channels are typically rectangular in cross-section, in particular square or round.

In practice, the flow channels often have a relatively small cross-section in comparison with the fan diameter, or the side walls of the flow channels, which deflect the air flowing out from the fan in the axial direction, are arranged relatively close to the fan outlet, which results in considerable flow losses for free-running fans. For example, in the case of a square or rectangular channel, the distance between opposite sidewalls is equal to or less than 1.6 times the maximum fan blade diameter of a built-in fan. These flow losses are due to the fact that in a central or near-axis region behind the fan forms a backflow, which induces a large, toroidal vortex. This leads to considerable power losses and noise generation. The losses are greater, the narrower or smaller the channel builds. In a very similar way, losses occur when adjacent parallel-connected radial or diagonal fans have a small distance from one another and the outflowing air is thereby rapidly deflected in the axial direction. To counteract these losses, it is already known from practice, by the Use of Nachleiträdern to take the swirl from the flow, whereby flow losses are significantly reduced. The use of Nachleiträdern is structurally complex. In addition, the use of Nachleiträdern the noise emission is increased. For the relevant state of the art, reference is made, by way of example only, to DE 195 23 339 A1, which shows in concrete terms an axial fan arranged in a housing with a Nachleitrad, whereby a stabilization of the air flow generated by the impeller is to take place. Accordingly, the Nachleitrad is arranged on the pressure side of the blower. From EP 0 497 296 B1 a generic arrangement is known in which a fan is arranged in a housing. On the pressure side, a plurality of relatively thick intermediate walls are provided, which form two square annular channels with a small flow cross-section, which are arranged concentrically. On the pressure side, a filter is arranged downstream. The inner wall parts are made of a sound absorbing material for the purpose of noise reduction of the unit. In addition, the nested ring channels serve a uniform flow distribution.

In the arrangement described above is disadvantageous that the provision of the wall parts and creation of relatively narrow ring channels brings significant flow losses. If the partitions were not made of sound-deadening material, significant flow noise would result.

In addition, the partitions have a considerable axial extent due to their geometry and arrangement, so that a considerable axial space is required together with the fan. This is particularly disadvantageous if the fan is to be accommodated in a modular housing.

In the light of the above, the present invention has the object to eliminate the disadvantages known in the prior art as far as possible. Above all, a low-noise operation should be possible while avoiding flow losses. In addition, the fan module and the arrangement of fan modules should differ from competitive products in design and construction. The above object is solved by the features of the independent claims 1 and 15. Thereafter, the fan module comprises a fan, which may be arranged in a housing. An arrangement consists of one or more fan module (s), which are arranged in a modular combination for the design of a fan wall, and depending on the embodiment of a flow channel or a comparable ventilation system in which the fan module (s) is / are installed, the Flow channel regularly has a rectangular, square or round cross-section. On the pressure side, a device for reducing or suppressing a return flow is provided, which serves to equalize the outflowing air.

The device consists of a mechanical backflow blocker, which is arranged approximately in the middle in the flow path and blocks a part of the flow cross section. The backflow blocker is a compact component which, in a comparatively flat design, has only a small axial size.

In an advantageous embodiment of the return flow blocker is designed as a plate or preferably flat box (flat configuration in the axial direction), the active surface is transverse or orthogonal to the flow direction. The return flow blocker is an obstacle in the flow path, but does not form any additional flow paths or flow channels. With regard to the air flow, the backflow blocker is designed to be self-contained.

In a further advantageous embodiment of the return flow blocker has substantially the same or similar contour or cross-sectional shape as the housing or the flow channel. This means that in the case of, for example, a square flow channel, the backflow blocker has a square base area. When the flow channel is round in cross section, the backflow blocker is correspondingly provided with a round cross section.

In a particularly advantageous embodiment, the return flow blocker has a preferably central recess or a passage. In these Recess in or through this recess protrudes, in the installed state of the Rückstromblockierers, a portion of the motor of the fan, so that the Rückstromblockierer can be arranged or positioned so that it does not protrude on the pressure side over the end of the fan. Such an embodiment has the enormous advantage that the size of the arrangement in the axial direction is not increased by provision of the backflow blocker, after which the arrangement can maximally have the axial size of the fan. In addition, it is conceivable that the return flow blocker is designed like a frame, wherein the part of the fan projecting into the return flow blocker or through the backflow blocker lies on the pressure side within the frame legs and is protected at least laterally. In addition, the peripheral frame promotes the formation of the flow path while avoiding turbulence. The return flow blocker is advantageously dimensioned such that it reduces the effective flow cross section within the housing or the flow channel by 40 to 70%, preferably by about 55%.

With the Rückstromblockierer a significantly lower speed spread and a homogeneous flow of subsequent components are achieved in comparison to the prior art. As a result, a reduced distance to downstream components such as a filter or a heat exchanger is possible. The homogeneous flow pattern also promotes the functionality of the following components, namely due to the homogeneous flow, and this with at least low reduction of the pressure side acoustics.

In principle, it is possible that the return flow blocker is made of a preferably flanged or folded sheet metal. Likewise, this can be made of plastic, one-piece or multi-part, manufactured, with the items of Rückstromblockierers be joined together by joining technology. Furthermore, it is conceivable that the return flow blocker is made as a sound-absorbing component, for example as a perforated plate with backfill with sound-absorbing material, or of a dimensionally stable sound-absorbing Material is made completely, for example, a foamed plastic with preferably open porosity.

The backflow blocker can have its own suspension, which positions it in the housing or flow channel as described above. It is also conceivable that the return flow blocker uses an existing suspension of the fan. The return flow blocker can be screwed to the suspension or clipped onto the suspension or snapped or clamped there. Any force / positive connections between the backflow blocker and the suspension are conceivable, the attachment should be reversible to favor access to the fan.

It should be noted that such a backflow blocker for maintenance or repair of the fan can be easily removed. It is also conceivable to retrofit a generic arrangement with a return flow blocker, namely, for example, using the already provided suspension of the fan.

The special suspension of the return flow blocker or the suspension of the fan used by the backflow blocker can consist of round material, which promotes the flow conditions. In the context of a particularly simple embodiment, the suspension of a flat sheet, such as metal strips or sheet metal strips, as well as plastic, exist. In a further advantageous embodiment, the fluidic function of the return flow blocker and the mechanical function of the fan suspension can be taken over by one and the same part, preferably a sheet metal part. In a particularly advantageous manner, the return flow blocker or the suspension of the fan in the housing or in the flow channel can be moved in its position, namely along the suspension or along positioning rails, which are associated with the suspension. This allows the otherwise identical fan module without further measures with fans with different engines, different impeller sizes and impeller types, which often have different heights, use.

As already mentioned above, the backflow blocker can be made of sheet metal or plastic, wherein the surface can be structured in order to promote the effect of the backflow blocker. In the case of a production of plastic, this may consist of foamed plastic with open porosity.

In a further advantageous embodiment of a fan module, a pressure-side contact protection is formed which, in addition to the backflow blocker, is required only in those areas which are not shielded by the backflow blocker.

The inventive arrangement consists of one or more juxtaposed, parallel fan modules, often arranged in flow channels or comparable ventilation systems. Since the fan modules have a backflow blocker, they can be positioned in a compact manner relatively close to each other or close to sidewalls of flow channels, without having significant flow losses. Such arrangements may optionally be formed of fan modules with or without housing, the backflow blocker in each case unfolds its positive effect. In the case of fan modules with housings, adjacent fan modules can advantageously be connected to one another via the housing, in particular via the frame construction of the housing.

The backflow blocker can be arranged downstream of any functional units to which the backflow blocker has a positive effect insofar as it brings about a homogenization of the flow. Thus, a filter or a filter group or a heat exchanger or a heating unit can be arranged downstream.

There are now various possibilities for designing and developing the teaching of the present invention in an advantageous manner. For this purpose, on the one hand to the claims subordinate to claim 1 and on the other hand to the following explanation of preferred embodiments of the invention with reference to the Drawing to refer. In conjunction with the explanation of the preferred embodiments of the invention with reference to the drawings, also generally preferred embodiments and developments of the teaching are explained. In the drawing show

1 is a perspective view of an embodiment of a fan module according to the invention, in a pressure-side plan view of the fan module of Figure 1, in a pressure-side plan view another embodiment of a fan module according to the invention, without backflow blocker, with visible suspension of the fan, in a perspective view of the The object of Figure 3, but with mounted Rückstromblockierer, in a pressure-side plan view the subject matter of Figure 4, in a side view, with disassembled side wall, the fan module of Figures 1 and 2, in a side view, with disassembled side wall, the fan module of the figures 3 to 5, in a perspective view, from the suction side, an embodiment of a fan module according to the invention, without housing, for installation in a flow channel, in a view from the pressure side, the embodiment of Figure 8,

10 is a side view of the subject matter of Figures 8 and 9, in a pressure-side plan view of the subject matter of Figures 8 to 10, in a perspective view another embodiment of a fan module according to the invention in a housing with downstream or integrated sound absorber, in a pressure-side plan view the subject of Figure 12, in a side view, with the side wall removed , The object of Figures 12 and 13, in a perspective view another embodiment of a fan module according to the invention with safety guard, in a perspective view a compact arrangement of 4 parallel fan modules, and in a perspective view another embodiment of a fan module according to the invention, in which the backflow preventer is integrated in the fan suspension.

Fig. 1 shows an embodiment of a fan module 24 according to the invention, wherein there is a subsequently always referred to as a fan 1 radial fan in a housing 2 is arranged. The fan 1 may be any type of fan.

The fan module 24 is to be understood in terms of a compact, modular component and may be an element of an arrangement with one or more fan modules, which may advantageously be arranged directly adjacent to one another and / or one above the other, for example a fan wall. Again, results in a compact design. The housing 2 has a frame structure 3, which is laterally closed by side walls 4. On the inflow side, the housing 2 is closed by a nozzle plate 5. In the nozzle plate 5, an inlet nozzle 23 is mounted or integrated for the fan 1. The attachment of the fan module 24 in a flow channel, a ventilation system or on another fan module can be done via various elements of the housing 2, in particular via the nozzle plate 5, the frame structure 3 or the side walls. 4

FIG. 1 clearly shows that on the pressure side (outflow side) a special device is provided which serves to reduce or suppress backflow and to even out the outflowing air. This device is hereinafter referred to as Rückströmblockierer 6. It is a fluid-mechanical component, which advantageously has an outer contour of the housing 2 similar outer contour. In the exemplary embodiment, the contours of the housing 2 and the return flow blocker 6, viewed in cross-section perpendicular to the fan axis, are approximately square. In particular, they can also be rectangular or hexagonal or have any other desired shape. The Rückströmblockierer 6 occupies about 55% of the housing cross-section, so that between the side walls 4 of the housing 2 and the Rückstrom- blocker 6 an annular channel 15 or air passage remains. In other embodiments, the shape of the outer contour of the Rückstromblockierers 6 also differ significantly from the shape of the inner contour of the housing 2, as long as the Rückströmblockierer occupies about 40% -70% of the housing cross-section in cross section.

The Rückströmblockierer 6 has as shown in the embodiment advantageously in the region of the annular channel 15 has an axial height, which is realized here by the frame 7. In particular, this axial height is higher than a sheet thickness, advantageously greater than 5% of the width of the housing seen in cross section or greater than 20% of the average width of the annular channel.

The return flow blocker 6 is still relatively thin in the axial direction compared to the axial height of the housing 2. In order to achieve optimum space savings, the axial height of the return flow blocker 6 is not It consists in the embodiment of a sheet metal, which is laterally bent or crimped to a circumferential frame 7. This also results in the compact design.

In the middle in the backflow blocker 6, an approximately circular recess 8 is provided, through which a part of the electric motor of the fan 1 protrudes. Thus, it is possible to push the return flow blocker 6 so far about the fan 1 and its pressure-side end 9 or position that the fan 1 itself sets the necessary axial length of the fan module 24, and not about the return flow blocker 6, with additional space ,

Figure 1 further reveals that the return flow blocker 6 is attached to a suspension 10, which consists of round struts 1 1. At this suspension and the fan 1 is fixed with its electric motor, whereby the connection of the fan 1 is ensured to the housing. The struts 1 1 are screwed on angle plates 12, each with two side walls 4, whereby not only a suspension 10 for the fan 1 and the return flow blocker 6 but also a stabilization of the housing 2 is realized. Instead of the round struts 1 1 and the round material and thin metal struts can be used, the use of round material favors the air flow and reduces the flow resistance.

It should be noted at this point that investigations have shown that the optimal geometry of the return flow blocker 6 does not depend or only at the edge of the type of impeller or the impeller size of the fan 1. Rather, it is primarily about the ratio of the cross-sectional areas of the housing 2 and the Rückstromblockierers 6, seen in the axial direction. This finding allows the use of different fan impellers in the same housing or flow channel with the same return flow blocker 6, which has a favorable effect on the manufacturing costs and the variety of parts.

FIG. 1 further shows that the circular recess 8 has a widened recess 13 or notch in the lower region, through which is accessible from the pressure side by an electronics / control area 14 of the fan 1, without dismantling the return flow blocker. Regardless, the return flow blocker 6 can be removed according to the fastening means used, so that access to the entire fan 1 is easily possible. The laying of the cable can be done through the recess 13 to allow easy removal of the Rückstromblockierers without disassembly of the electrical connection cable.

Figure 2 shows the compact fan module 24 of Figure 1 in an axial top view, i. from the print side. Based on FIG. 2, it can roughly be estimated that the backflow blocker 6 occupies approximately 55% of the cross-sectional area of the housing 2. Due to the provision of the return flow blocker 6 on top of that, the pressure-side sound level can be reduced, wherein the return flow blocker 6 is made of sheet metal in the embodiment shown here. It is also conceivable to coat the return flow blocker 6 with sound-absorbing material or to produce a total of this. It is also conceivable to manufacture the return flow blocker 6 made of plastic, for example by injection molding. Advantageously, foamed plastic can be used to save weight and increase the Schallabsortion. In the case of cast-back blockers 6, devices for fastening the return-flow blocker can be integrated on a suspension 10, which, for example, allows a simple clipping onto the suspension 10.

FIG. 3 shows a further exemplary embodiment of a fan module according to the invention, but without the backflow blocker 6, so that a suspension 10 for the fan 1 can be seen unobstructed. The suspension 10 comprises vertical profiles 16 and lower and upper adjustment rails 17 for the variable axial positioning. The adjustment rails 17 are provided with elongated slots, along which a displacement of the suspension 10 via the profiles 16 is possible. This makes it possible to install in a housing 2 different fans, which have different axial height. Thus, the same fan impeller with different engine lengths can be used, or fans of different design or impeller type are installed in the same housing. As for the functioning of the backflow Blocker the ratio of its cross section to the housing cross-section is crucial, the same backflow blocker can be used for different fans. FIG. 4 shows the fan module according to FIG. 3, but with a downstream bellows blocker 6. For example, it can be clearly seen that the axial position of the return flow blocker is always coupled to the axial position of the vertical braces 16 of the suspension 10. As a result, a fluidically favorable distance to the fan outlet can be realized independently of the fan used without any special further measures.

FIG. 4 further clearly shows that a part 9 of the electric motor of the fan 1 projects into the return flow blocker 6 or through the recess 8 in the backflow blocker 6, so that the provision of the backflow blocker 6 in no way satisfies the required installation space and thus the volume of the housing 2, whereby a retrofitting of conventional arrangements with a return flow blocker 6 is possible.

FIG. 5 shows the fan module from FIG. 4 in an axial plan view, ie from the pressure side. There, the return flow blocker 6 is attached to the suspension 10 from the pressure side with a total of four screws 18. To make the fan 1 accessible for maintenance or repair, the return flow blocker 6 can be easily disassembled by loosening the screws 18. It should be noted at this point that any other fastening variants are conceivable, for example fastening by clipping, snapping or clamping. Such mounting options are particularly advantageous in non-structural embodiments of the Rückstromblockierers 6, if this consists for example of foamed plastic. As a particularly advantageous fastening variant in return current blockers made of sheet metal special Klipselemente have been found, as they are common in the same or similar manner in the installation of cable conduits in electrical installation. These Klipselemente be clipped on the one hand in designated punched holes in the sheet metal of the Rückstromblockierers 6, and on the other on round struts 1 1 a suspension 10 also clipped. In the same way it is also conceivable to use similar clip elements for flat material suspensions, which optionally have corresponding punched-out sections. FIG. 6 shows the fan module from FIGS. 1 and 2 from the side, the side wall 4 being dismantled on this side. In the background you can see the opposite side wall 4.

The provided there Rückstromblockierer 6 prevents air backflow in a central, near-axis region towards the fan 1. A toroidal, lossy vortex can not arise due to the provision of Rückstromblockierers 6.

Furthermore, it should be noted that in the embodiment shown here, the channel width is at 1.6 times the maximum axial diameter of the impeller blades, the range of this ratio typically being between 1.3 and 1.8.

Furthermore, FIG. 6 clearly shows the special suspension 10 provided there, which comprises round struts 11 in the exemplary embodiment.

FIG. 7 shows a view corresponding to FIG. 6, this view being based on the exemplary embodiment from FIGS. 3 to 5. The suspension 10 provided there comprises vertical profiles 16 and adjustment rails 17 for optimum positioning.

Figures 8 and 9 show a further embodiment of a fan module, respectively in a schematic view, namely Figure 8 from the suction side and Figure 9 from the pressure side. The fan module 24 has no housing and is used for arrangement alone or with other parallel-connected fan modules in a flow channel. This is a built-in module for a flow channel, not shown in the two figures. Otherwise, the same statements apply to the previously described embodiments of the arrangement in a housing 2. In the embodiment shown in FIGS. 8 and 9, the return flow blocker 6 reduces the effective flow cross section in the flow channel instead of in the housing 2 as described above. Otherwise, the same statements apply as before.

Again, a suspension 10 is provided from round material. This measure minimizes losses. The return flow blocker 6 is made in sheet metal and attached to the round material or to the struts 10 of the fan suspension 10, namely clipped.

Advantageously, a return flow blocker 6 is designed with its fastening means so that it can be attached both to a suspension 10 of a fan module 24 without housing and to a suspension of a fan module 24 with housing 2, for example according to FIG. Thus, identical backflow blockers 6 can be used for both types of fan modules.

The fan module 24 shown in FIGS. 8 and 9 can be installed in an air conditioning box unit with an axial flow channel, whereby the effect of the backflow blocker 6 becomes particularly evident, since fluidically a system is produced which is comparable to the embodiment shown in FIGS. 1 and 2 is. The return flow blocker 6 is advantageously designed such that it can be clipped onto both a suspension 10 according to this figure and to a suspension 10 according to Figures 1 and 2. In addition, the backflow blocker 6 is optionally attachable, in case it is needed. If the provision of the Rückstromblockierers 6 not desired, it can be removed or omitted from the outset. In any case, it can be retrofitted to fans already in central air conditioning units or similar. The same principle can also be implemented with differently designed suspensions, for example based on a flat material construction according to FIGS. 3 to 6.

FIG. 10 shows the fan module from FIGS. 8 and 9 from the side, the suspension 10 being particularly clearly visible there. FIG. 11 shows the object from FIGS. 8, 9 and 10 in a plan view from the pressure side, frontal view of the backflow blocker 6 being recognizable therefrom.

FIG. 12 shows, in a schematic view, a further exemplary embodiment of a fan module according to the invention, where the fan 1 is arranged in a housing 2.

On the pressure side, a sound absorber 20 consisting of perforated plate is arranged, which adjoins the backflow blocking device (not shown in FIG. 12) and extends to the pressure-side edge of the housing 2.

The sound absorber 20 consists of perforated sheet metal, it being possible for a sound-absorbing material to be used in the inner, central area 25 surrounding the perforated sheet metal. Likewise, it is conceivable to manufacture the sound absorber 20 as a whole from a dimensionally stable sound-absorbing material.

FIG. 13 shows the fan module from FIG. 12 in a plan view from the pressure side. The perforated sound absorber 20 is clearly visible, especially in that it adjoins the return flow blocker 6 with the same shape. The suspension 10 with round struts 1 1 is also recognizable.

Figure 14 shows the fan module of Figures 12 and 13 from the side with the side wall removed. Here, too, it can be clearly seen that the sound absorber 20 directly adjoins the return flow blocker 6, wherein both components are fastened and positioned together via the suspension 10. It can be clearly seen in FIG. 14 that the return flow blocker 6 is fastened to the struts 11 of the suspension 10 by means of a simple clip connection 26. The sound absorber 20 acts in relation to the air flow from its outside.

Again, the axial position of the suspension 10 can be adjusted and adapted to different fans 1. At the inlet nozzle 23, a pressure-reducing device 22 is provided, which can serve to measure the volume flow during operation of the fan 1. In the embodiment shown in FIGS. 12 to 14, the sound absorber 20 has the shape of a truncated pyramid. As a result, expanding flow channels 15 ^{* are formed} in the sense of a diffuser between the side walls 4 and the sound absorber 20 or its wall 19, which serve to convert dynamic energy into pressure energy. Also, this can cause an increase in efficiency, with an optimal positioning of both the fan 1 and the return flow blocker 6 including sound absorber 20 is to be assumed. Expanding flow channels 15 ^* , in particular with other housing cross-sections, can also be realized by means of sound absorbers which have a shape deviating from the truncated pyramid, for example the shape of a truncated cone. The sound absorber 20 may also have the shape of a cuboid, so that no diffusers are formed. In any case, can be reduced by the use of the sound absorber 20 in a channel system radiated sound power. The outer, square flow path of the housing 2 extends from the backflow blocker 6 in the axial direction over the entire effective area of the sound absorber 20, wherein it is also conceivable for the sound absorber 20 to extend out of the housing 2 into a flow channel , wherein this is in the installed state, for example in a central air conditioning unit, then surrounded by channel walls similar to the side walls 4 of the housing 2, whereby the sound absorber 20 can exert its effect.

The outer walls 4 of the housing 2 may be formed as a sound absorber. This is possible, for example, in that 4 panels of sound-absorbing material are used as outer walls. It is also possible to make the outer walls 4 of perforated plate and attach a sound absorbing material outside of the flow path. In the radial direction (transverse to the side wall 4) there is space for this, which is given by the overall height of the frame structure 3 transversely to the housing side wall 4, as can be seen well in Fig. 1, for example. FIG. 15 shows a further exemplary embodiment of a fan module 24 with return flow blocker 6. In this exemplary embodiment, a pressure-side contact protection 27 in the form of a contact protection grid is integrated on the fan module 24. A pressure-side contact protection is necessary if the outflow side of a fan module 24 can be accessible in fan operation. Since the backflow blocker 6 protects against contact with the fan for the inner, near-axis region, the additional contact protection 27 can be limited to the regions of the annular channel 15, which contributes to material and weight savings. Since the distance of the contact protection 27 to rotating parts of the fan 1 in the region of the pressure-side outlet of the annular channel 15 is relatively large, large grid mesh sizes can be selected, which is advantageous for efficiency and noise. The touch guard 27 may be formed in various ways, as a stamped sheet metal, with a mesh structure or a wire ring grid construction. The fastening can take place on the housing 2, on the backflow blocker 6 or on both, and optionally with screws, rivets, clips, snap-in hooks or the like. Otherwise, this embodiment is comparable to that according to, for example, FIG. 1.

FIG. 16 shows an advantageous arrangement of four fan modules 24 according to FIGS. 8 to 11. It is fan modules 24 without housing, which are arranged side by side in parallel. This arrangement could be used, for example, in a flow channel surrounding the entire assembly. A special feature of this arrangement is that between adjacent backflow blockers 6 are no side walls. Instead of annular channels 15 as in the case of fan modules with housing, flow channels 15 ^{** are} formed between adjacent backflow blockers. Also in this arrangement, the return flow blocker 6 cause comparable advantages as in embodiments with housing. In central, near-axis areas behind the fans 1, backflow is reduced or prevented, the efficiency increased and the noise emission reduced. The compactness of the arrangement is given by the small lateral distance of the fan modules 24, whereby an axial further flow of the air is forced and the use of Rückstromblockierern 6 is advantageous. Particularly advantageous is the use of reverse flow blockers 6 in adjacent Fan housings 24 without housing, if an axial distance of adjacent fans 1 1, 6 x D below, where D is the largest diameter of a fan blade of the respective fans 1. Finally, FIG. 17 shows a further embodiment of a fan module 24 with housing 2 and return flow blocker 6. In this embodiment, the return flow blocker 6 is designed as a supporting part and integrated into the fan suspension, ie fan suspension 10 and return flow blocker 6 are the same sheet metal part. In this respect, here the suspension 10 assumes a fluid-mechanical positive acting function. The fan is attached via its motor similar to that described in FIG. 3 on the carrying backflow blocker 6, 10, wherein the pressure-side end 9 of the motor protrudes through a recess 8 in the carrying backflow blocker 6, 10. Advantage of such an embodiment is that fewer parts are needed for the construction, since the functions of the return flow blocker 6 and the suspension 10 are taken over by the same part. The disadvantage, however, is that the return flow blocker 6 must be made of a strong sheet metal in order to take over the supporting function. For static reasons, this would not actually be necessary over the entire dimensions of the return flow blocker 6.

In this respect, mixed forms are also conceivable in which a load-bearing part of the return flow blocker 6 is made of strong sheet metal, non-load-bearing parts of weaker sheet metal. However, this again leads to a larger number of parts. With regard to further advantageous embodiments of the teaching of the invention reference is made to avoid repetition to the general part of the specification and to the appended claims.

Finally, it should be expressly pointed out that the above-described embodiments of the teaching according to the invention are merely for the purpose of discussing the claimed teaching, but do not restrict it to the exemplary embodiments. LIST OF REFERENCE NUMBERS

Fan, centrifugal fan

casing

frame structure

Side wall

nozzle plate

Backflow blocker

Frame (of the backflow blocker) Cutout (of the backflow blocker) Pressure side end of the fan motor Suspension

pursuit

Winkelblech

further recess in the backflow blocker Elektrik- / control area of the fan ring channel

* diffuser-like widening annular channel ^** flow channel between adjacent ones

Fan modules or backflow blockers

vertical profile of the suspension

adjusting rail

screw

wall

sound absorber

not forgiven

Pressure reduction device

inlet nozzle

fan module

Sound absorbing material area Clip connection

Touch protection, contact protection grid

Claims

1. fan module comprising at least one fan (1), optionally a nozzle plate (5) and a suspension (10), wherein the pressure side, a device for reducing or suppressing a backflow of the outflowing air is provided, wherein the device as a mechanical Rückstromblockierer (6) is executed, which is arranged approximately centrally in the flow path and blocks a part of the flow cross-section.

2. Fan module according to claim 1, characterized in that the return flow blocker (6) is designed as a plate or preferably flat box whose largest effective area extends transversely or orthogonally to the flow direction.

3. Fan module according to claim 1 or 2, characterized in that, viewed in the axial direction, the outer contour or cross-sectional shape of the Rückstrom- blocker (6) is substantially equal or similar to the inner contour or cross-sectional shape of the housing (2) or the surrounding flow channel ,

4. Fan module according to one of claims 1 to 3, characterized in that the inner contour of the housing (2) or of the surrounding

Flow channel seen in cross section in the axial direction is rectangular, in particular square, and that the return flow blocker (6) is designed in accordance with cross-section in the axial direction rectangular or square.

5. Fan module according to one of claims 1 to 3, characterized in that the inner contour of the housing (2) and the surrounding flow channel in cross-section seen in the axial direction is round and that the Rückstromblockierer (6) is designed in accordance with cross-section in the axial direction seen round ,

6. fan module according to one of claims 1 to 5, characterized in that the return flow blocker (6) has a preferably central Has passage (8) or a passage through which / a pressure-side portion of the engine of the fan (1) projects into or through.

7. Fan module according to one of claims 1 to 6, characterized in that the return flow blocker (6) reduces the effective flow cross section by 40% to 70%, preferably by about 55%.

8. fan module according to one of claims 1 to 7, characterized in that the return flow blocker (6) is made as a sound-absorbing component, preferably made entirely of sound-absorbing material.

9. fan module according to one of claims 1 to 8, characterized in that the return flow blocker (6) at the same time has a supporting function for the fan (1), that is component of the suspension (10), the fan (1) on the housing ( 2) or attached to the nozzle plate (5).

10. fan module according to one of claims 1 to 8, characterized in that the return flow blocker (6) has no supporting function and uses a suspension (10) of the fan (1).

1 1. A fan module according to claim 10, characterized in that the return flow blocker (6) screwed to the suspension (10) or on the suspension (10) clipped, locked, clamped, etc. is.

12. Fan module according to one of claims 1 to 1 1, characterized in that the suspension (10) consists of a round material or of a flat material.

13. Fan module according to one of claims 1 to 12, characterized in that the suspension (10) and thus the return flow blocker (6) in the housing (1) or in the flow channel is adjustable in position, in particular along the suspension (10) axially to Nozzle plate (5) towards or away from this is adjustable.

14. Fan module according to one of claims 1 to 13, characterized in that the return flow blocker (6) is made of sheet metal or plastic, in particular surface-structured and / or foamed plastic.

15. Arrangement comprising at least one or more fan module (s) (24) according to one of claims 1 to 14 in a flow channel or a comparable ventilation system, wherein the flow is forwarded to the or the fan module (s) (24) in the axial direction.

16. Arrangement according to claim 15, characterized in that the distance of a wall of a flow channel or a side wall (4) of a housing (2) of a fan axis is less than 0.8 times the largest diameter of an impeller blade of the relevant fan (1). is.

17. Arrangement according to one of claims 15 or 16, characterized in that at least two fan modules (24) are arranged side by side

18. Arrangement according to one of claims 15 to 17, characterized in that two adjacent fan modules (24) with their housings (2) lie directly against each other and are optionally secured to each other.

19. Arrangement according to one of claims 15 to 18, characterized in that the fans (1) of two adjacent fan modules (24) have an axial distance equal to or less than 1.6 times the largest diameter of an impeller vane of a respective one Fan (1) is.

20. Arrangement according to one of claims 15 to 19, characterized in that one or more fans (1) have no housing (2).

21. Arrangement according to one of claims 15 to 20, characterized in that the return flow blocker (6) on the pressure side, a heat exchanger is arranged downstream.