DE102018105828A1 - Device for expanding an air volume flow - Google Patents

Abstract

The invention relates to a device (1) for expanding an air volume flow, comprising
- An air distribution space (3), comprising
- An air inlet cross-section (9) for connection to an air duct (8) and
- A beam generating device (4) having a plurality of passage openings (5), which together form an air passage cross-section,
- An intermediate space (7) into which the passage openings (5) open and
a homogenizing device (6), through which the air volume flow passes out of the intermediate space (7) and which defines an air outlet cross-section (22) on a side facing away from the intermediate space (7),
wherein the air outlet cross section (22) is substantially larger than the air inlet cross section (9) and the passage openings (5) in each case from the air distribution space (3) facing inlet region (12) and the intermediate space (7) facing channel (11) composed, the air volume flow in each case in an inlet region (12) is deflected. In order to develop an alternative device for distributing an air volume flow, which is characterized by a low pressure drop, a low construction volume and a homogeneous distribution of the air flow, the invention proposes that the inlet regions (12), from the air distribution space (3) in the direction of Viewed intermediate space (7), trumpet-shaped, tapered or stepped taper, wherein inlet cross sections (13) of the passage openings (5) are located substantially within a common entrance level.

Description

introduction

• - einen Luftverteilraum, umfassend
  • - einen Lufteintrittsquerschnitt zur Verbindung mit
  • - einem Luftkanal und
  • - eine Strahlerzeugungseinrichtung, die eine Vielzahl von Durchtrittsöffnungen aufweist, die gemeinsam einen Luftdurchtrittsquerschnitt bilden,
• - einen Zwischenraum, in den die Durchtrittsöffnungen münden und
• - eine Vergleichmäßigungseinrichtung, durch die der Luftvolumenstrom aus dem Zwischenraum heraus hindurchtritt und die auf einer dem Zwischenraum abgewandten Seite einen Luftaustrittsquerschnitt definiert,

wobei der Luftaustrittsquerschnitt wesentlich größer als der Lufteintrittsquerschnitt ist und sich die Durchtrittsöffnungen jeweils aus einem dem Luftverteilraum zugewandten Einlaufbereich und einem dem Zwischenraum zugewandten Kanal zusammensetzen, wobei der Luftvolumenstrom jeweils in einem Einlaufbereich umgelenkt wird.The invention relates to a device for expanding an air volume flow, comprising

• - An air distribution room, comprising
  • - An air inlet cross section for connection with
  • - an air duct and
  • a jet generating device having a plurality of passage openings, which together form an air passage cross section,
• - A space in which the openings open and
• a homogenizing device, through which the air volume flow passes out of the intermediate space and which defines an air outlet cross section on a side facing away from the intermediate space,

wherein the air outlet cross-section is substantially larger than the air inlet cross-section and the passage openings each composed of an inlet region facing the air distribution space and a channel facing the gap, wherein the air volume flow is deflected in each case in an inlet region.

State of the art

In various fields of technology, the need for uniform air distribution over a larger cross-section, the supply air is supplied for economic, technical and space reasons via a channel or pipe as small as possible cross section. Accordingly, there is a drastic cross-sectional widening between an air supply line and adjoining air-technical devices or systems, the velocity of the supply air decreasing as the cross-sectional area increases. For this reason, the air outlet cross section is substantially larger than the air inlet cross section, it being assumed in the context of the present application that the air outlet cross section is at least five times, preferably ten times, more preferably fifty times greater than the air inlet cross section. It is understood that the device can be adapted to individual requirements and the aforementioned size ratios are mentioned only by way of example.

Due to the cross-sectional widening, the flow conditions of the supply air are negatively influenced and turbulences occur. For uniform expansion of the volume flow devices are arranged, which can also be referred to as diffusers.

In practice, it proves problematic to decelerate air evenly. In moving air, the static pressure decreases, whereby currents always have the tendency to form round beam shapes. Irregularities in the jet pattern tend to increase with the run length. For this reason, it is often possible to achieve a uniform volume flow in the outlet of the diffuser only with very large pressure losses. Alternatively, diffusers with continuous cross-sectional widening are known, which have a very large design due to the very slow cross-sectional widening and prove to be useless in many places.

From the DE 29 41 276 A1 a flow distribution device is known, which comprises a perforated plate formed as a boundary wall. The openings in the plate are evenly distributed and each have a protruding into a distribution space lip-shaped deflection. Due to the impact of the supply air on the deflection devices, this is deflected by 90 °, passed into the openings and leaves on the other side of the plate, the device in the room to be ventilated. This is intended to produce a uniform volume flow.

The impact of the supply air on the deflecting devices attempts to divide the entire supply air volume flow into many individual partial volume flows, these partial volume flows of the known device having a very turbulent flow behavior. In addition, the lips projecting into the distribution space also prove inappropriate with respect to the airflow within the distribution space. The protruding lips disturb on the one hand a uniform air flow and on the other hand the air distribution within the distribution space. While sufficient supply air hits the upper lips, the following lips, which are in the "shadow", are hardly supplied with supply air. Overall, the air distribution achieved is not suitable for high demands.

task

It is an object of the present invention to develop an alternative device for distributing an air volume flow, which is characterized by a low pressure drop, a low construction volume and a homogeneous distribution of the air flow.

solution

Based on the aforementioned device, the above object is achieved in that the inlet regions, viewed from the air distribution space in the direction of the gap, taper trumpet-shaped, conical or stepped, wherein inlet cross sections of the passage openings are located substantially within a common entry level.

The inventive shape of the inlet regions of the passage openings a very good uniform distribution of the volume flow is achieved, so that high air velocities in the upstream air duct can be allowed by the special "hole shape" of the passages. As a result of the hole shape, which tapers in the inlet area in the flow direction, starting from a larger diameter, a deflection of the air flow into each individual passage opening is achieved. Thus, the static pressure above the jet generating device is no longer decisive, but the total pressure. Since this is relatively constant even with very long nozzle boxes, a very uniform outflow is achieved over the entire length of the beam generating device.

In a trumpet-shaped design of the inlet regions, a wall of the same viewed in cross-section is slightly convex. If it is a conical inlet areas, the wall of the same viewed in cross section is rectilinear. In a stepped embodiment of the inlet regions, there are steps between differently shaped, in particular in each case cylindrical, sections. Due to the narrowing of the cross section over the height of the inlet area arcuate streamlines arise, so that such inlet areas also referred to as "rounded inlet". The cross-section of the channels is at least substantially constant over its length.

The passage openings preferably have a round cross section, and it would also be conceivable to form the passage openings with an oval or angular cross section. It is only important that, viewed from the inlet cross section in the flow direction, the cross section tapers over the height of the inlet region.

As already mentioned, the volume flow in the air distribution space is uniformly introduced into the same due to the inlet regions of the passage openings according to the invention, which in contrast is not exactly the case in the inlet region sharp-edged through openings, ie through openings with a constant cross section in the inlet region. Although a distribution of the volumetric flow into a multiplicity of partial volume flows also takes place at passage openings formed with sharp edges, the flow conditions are extremely turbulent both within the passage openings and above the passage openings in the air distribution space, since in addition to the inlet areas in the closed areas of the jet generating device, in FIG where there are no openings, turbulence occur. This is due to the fact that the supply air meets the closed area immediately adjacent to an inlet opening of a passage opening. According to the present invention, however, the inlet opening of the respective passage openings is widened and a side surface thereof is chamfered with respect to a central axis of the passage opening, so that a gentle deflection of the volume flow is achieved. This "countersink" has a circumferential side surface which encloses an angle between 25 ° and 45 ° with the entrance level. The side surface of the "countersinking" can be arched or curved in the case of a trumpet-shaped design of the inlet region, wherein a mean angle should then advantageously have the previously mentioned amount.

For the purposes of the invention, inlet cross-sections of the passage openings are located substantially within a common entry plane. It is essential that the entry plane in a longitudinal direction of the Luftverteilraums considered straight, so even, so that the flow can flow without obstacles. As a result, a uniform flow is achieved within the air distribution space. Typically, the air distribution space is elongate, which means that its length is greater than its width and height. Advantageously, the length is at least twice as large, advantageously at least four times as large, as the width and the height of the air distribution space. It is understood that depending on the application, the length can also be formed much longer. In the air distribution space, the volume flow, starting from the inlet cross-section, flows in the longitudinal direction of the air distribution space, wherein the air volume flow is typically deflected by 90 ° by means of the passage openings. If it is an air distribution space, which is arranged, for example, along a ceiling and its longitudinal direction thus extends horizontally, wherein the air duct has a likewise horizontal and perpendicular to the longitudinal direction of the Luftverteilraums extending longitudinal axis, the flow direction of the air flow in the air distribution space is also horizontal in the longitudinal direction of the air distribution space. If the jet generating device is arranged below the air distribution space, so that the longitudinal axes of the passage openings run vertically, the air volume flow is thus deflected in the vertical direction by means of the passage openings.

Viewed in a transverse direction of the air distribution space, the entry plane can be straight, curved or partially oblique.

Due to the fact that the jet generating device according to the invention can evenly divide the volume flow in the air duct independently of the flow velocity, a multiplicity of partial volume flows are generated uniformly over the surface of the jet generating device, which are directed substantially parallel to a longitudinal axis of the through openings.

Advantageously, the inlet regions and the respective corresponding channels have the same cross section in a transitional cross section in which the inlet region merges into the channel. Accordingly, the inlet area goes directly into the channel without having a jump in the through holes. This in turn has the advantage for the flow that no turbulence can arise.

According to an advantageous embodiment of the invention are blocking surfaces of the beam generating device, which are located between the inlet cross sections of the passage openings, also substantially within the entrance level. With regard to the formation of the beam generation direction in the longitudinal direction of the air distribution space, the blocking surfaces and the inlet cross sections must again run on a straight line, so that the flow within the air distribution space can flow uniformly without disturbing constrictions or expansions. In a direction perpendicular or transverse to the longitudinal direction of the air distribution space, the wording "substantially within the entry plane" means that the common plane can also be curved, for example, or else it can also be inclined in sections. For example, it is possible that the beam generating device is designed as a tube and thus has a cylindrical entry plane. Even in the case of a jet generating device designed as a tube, the blocking surfaces and the inlet cross sections, viewed in the longitudinal direction of the air distribution space, lie in each case on a line. In the transverse direction of the jet generating device thus formed, the blocking surfaces and the inlet cross sections are then located on a circle.

A development of the invention provides that viewed in a cross section - tangents of the wall of the inlet regions coincide with the entry plane. This results in a smooth transition from the entrance level to the side surface in the inlet region of the channels.

With regard to the trumpet-shaped, conical or stepped inlet regions, it is particularly advantageous if in each case a largest cross-section of the inlet regions is greater than twice the cross-section of the channels. In other words, the ratio of the inlet cross section to the cross section of the channel should be at least 2. Advantageously, the aforementioned ratio can also be 2.5 or at most 3. In the case of a circular cross-section of the passage openings applies the aforementioned ratio for the corresponding diameter. Since the largest cross section is located on the air distribution space side facing the passage opening, is achieved by this feature that a volume flow is introduced with a cross section corresponding to the largest cross section of the passage opening in selbige. In this way, relatively little supply air impinges on the blocking surfaces of the jet generating device and virtually no turbulence occurs in the air distribution space above the jet generating device. In the case of a circular cross-section of the passage openings, the channels have a cylindrical cross section and the inlet regions have a frustoconical cross section.

Due to the favorable flow conditions of the present device according to the invention, it is possible that a passage cross section of the beam generating device is smaller than 0.5 times the air inlet cross section of the air distribution space. According to the invention, it is also possible that the passage cross section is smaller than 0.4 times, smaller than 0.25 times or even smaller than the air inlet cross section. In individual applications, the aforementioned ratio may even be 0.05.

Advantageously, a ratio of a length of the channel to its diameter is at least 2. Advantageously, the ratio may be in a range of 2 to 10. Due to the length of the channel, the flow direction can be particularly impressed on the partial volume flow.

In a particularly preferred embodiment of the invention it is provided that the channels have on a side facing the gap a section in which a cross section is smaller than the cross section in the region of the remainder of the channel. The section thus forms a constriction of the channel, so that an opening cross-section of the channel is smaller than the cross-section of the channel itself. The section acts like a nozzle, which "aligns" the partial volume flows. The exiting partial volume flows are on the one hand extremely straight and are accelerated, so that the flow conditions are optimized. Essential for the function of the section is that the cross-section tapers, it is irrelevant whether the reduction of the cross-section leaps and bounds or continuously. Such an embodiment of the invention is suitable for diffusers to which particularly high demands are made. It has also proved to be advantageous if the cross-section of the section at the outlet thereof is less than 80% of the cross section of the channel.

An embodiment of the invention provides that the channels are formed by pipe sections. Tubes are available in different diameters and different materials as standard, so that standard products can be used. The tubes must first be cut to the required length and widened accordingly at one end. This method is simple, material-saving and is used in particular for larger channel diameters from 20 mm.

Furthermore, it is advantageous if there is a free space between outer sides of adjacent tubular bodies. In this way, the beam generating device can be made to save material and consequently also with low weight, since the tube body can be positioned spaced from each other according to the individual specifications.

With regard to the production of the beam generating device, it is also particularly advantageous if channel walls in the region of the inlet cross sections are connected to a plate-shaped upper part of the beam generating device, preferably made of metal and welded to the plate-shaped upper part, or are integrally formed with the plate-shaped upper part of the beam generating device, preferably as an injection-molded component or die-cast component. Thus, an economical production of the beam generating device is possible.

In addition, it is advantageous if there is a clear distance between the beam generating device and the equalizing device, which is three to ten times the diameter of a channel in the region of a constant diameter. This distance then corresponds to the length of the intermediate space measured in the flow direction. In the intermediate space, the individual partial volume flows can flow freely and the distance determines the so-called "free jet length", which is essential for the energy reduction in the flow. The flow from the beam generating device according to the invention are straightened, lose in the interspace of energy and occur evenly in the equalization in which a homogenization of the volume flow takes place.

Due to the construction according to the invention of the device with the jet generating device, the intermediate space and the equalization device, it is possible to obtain optimum flow conditions at the air outlet cross section, although a drastic widening of the volume flow may have previously occurred.

With regard to the homogenizing device has proved to be particularly advantageous if it comprises a sieve, a perforated plate or a porous material, wherein preferably a plurality of them are arranged one behind the other. By downstream of one or more screens, perforated plates or the arrangement of porous material, such as a sponge, after the gap, the high air velocity in the outlet of the channels (outlet cross-section) can be effectively used. Any irregularities in the outflow from the jet generating device can be compensated in the intermediate space, so that an excellent uniform distribution in the outlet cross section is achieved. Due to the uniformity at the outlet of the volume flow from the device, this can be used, for example, for the flow of slot nozzles, with a very uniform loading on the slot aisles can be achieved.

Furthermore, the device according to the invention is also suitable for acting on a further air distribution space, which is used to supply bulk beds or filter elements. Since the air velocities at the outlet of the device are already very low and without local peaks, the filter bed can again have a significantly larger inflow area. In practice, area ratios of 1:10 can be realized between the air outlet cross-section of the device and the filter bed. Based on the air inlet cross-section of the device, this means an area ratio of up to 1: 100 with very small deviations of the air velocity over the filter surface. Such area ratios are hardly achievable with other techniques, especially since the apparatus disclosed herein allows for design with great certainty.

Finally, it should be noted that the various individual features of the subclaims can be implemented individually for themselves or for a plurality of arbitrary combinations in variants of the invention.

Embodiment:

The invention described above will be explained in more detail with reference to two embodiments, which are illustrated in the figures.

• 1: einen Vertikalschnitt durch eine erfindungsgemäße Vorrichtung,
• 2: eine dreidimensionale Ansicht der Vorrichtung aus 1,
• 3: eine dreidimensionale Unteransicht der Strahlerzeugungseinrichtung aus 1,
• 4: eine dreidimensionale Ansicht einer alternativ ausgestalteten erfindungsgemäßen Strahlerzeugungseinrichtung und
• 5: Längsschnitte dreier alternativer Durchtrittsöffnungen.

It shows:

• 1 FIG. 2: a vertical section through a device according to the invention, FIG.
• 2 : a three-dimensional view of the device 1 .
• 3 : a three-dimensional bottom view of the beam generating device 1 .
• 4 : A three-dimensional view of an alternative embodiment of the invention beam generating device and
• 5 : Longitudinal sections of three alternative passage openings.

In the 1 is a device according to the invention 1 for the distribution of an air volume flow (arrow 2 shown) resulting from an air distribution space 3 , a beam generating device 4 with arranged therein through openings 5 and a homogenizer 6 composed, wherein between the beam generating device 4 and the equalization device 6 a gap 7 located. The air distribution room 3 is not over in the 1 illustrated means with an air duct 8th connected so that the air flow (arrow 2 ) from the air duct 8th via an air inlet cross section 9 in the air distribution room 3 arrives. The air duct 8th is formed by a tube and has a diameter of 200 mm. The device 1 has a cuboid housing 10 with a width of 220 mm, a height of 400 mm and a length of 2 m. In the case 10 are the beam generating device 4 and the equalizing device 6 arranged so that above the beam generating device 4 a free space remains, the air distribution space 3 forms. The air distribution room 3 is therefore from walls of the housing 10 and from an upper edge of the beam generating device 4 limited. Both the beam generating device 4 as well as the equalization device 6 are located below the air duct 8th ,

The parts of the device 1 are made of aluminum in the present example.

The beam generating device 4 has three mutually parallel rows of spaced passage openings 5 on, in the 1 only 2 passages 5 can be seen, since the passages 5 the third row are positioned offset and in the section according to 1 not to be seen. The passages 5 are each subdivided into a space 7 facing channel 11 and an air distribution space 3 facing inlet area 12 , In the present case, the cross section of the passage openings 5 round, leaving the channel 11 cylindrical and the inlet area 12 frusto-conical is formed.

As already mentioned, the inlet area 12 with a maximum diameter on one of the air distribution space 3 facing side of the beam generating device 4 and each defines an inlet cross section 13 , The diameter of the channels 11 is in each case 10 mm and the maximum diameter of the inlet areas 12 is 20 mm each. The length of the channels considered in the flow direction 11 is in each case 30 mm and the length of the inlet area considered in the flow direction 12 is 5 mm. By contemplated in the flow direction of the air flow constriction of the inlet areas 12 to a diameter similar to that of the channels 11 corresponds, there is an optimal deflection of the air flow in the individual passages 5 into it. Also, parts of the air flow that are outside a projection of the inlet cross sections 13 the individual passages 5 flow gently into the inlet area 12 sucked, leaving in a range of restricted areas 15 the beam generating device 4 extending between and adjacent to the inlet sections 13 the passages 5 do not form turbulence or turbulence. A flow direction within the passage openings 5 is an example with an arrow 28 symbolizes.

The entry cross sections 13 the passages 5 as well as the restricted areas 15 the beam generating device 4 are in the example shown in a plane. Alternatively, in a width direction of the device 1 a slightly curved formation of a surface of the beam generating device conceivable, wherein the radius of curvature should be greater than 1 m. Furthermore, an embodiment of the beam-generating device is conceivable in which the surface is also viewed in the width direction of the device with sections enclosing an angle with one another. Of particular importance is that the inlet cross sections 13 in a longitudinal direction of the device 1 considered, ie in the longitudinal direction of the housing 10 or the air distribution space 3 , run in a straight line, so that the air volume flow can flow in a straight line.

The sum of the cross sections of the passages 5 forms an air passage cross section of the beam generating device 4 , The individual passages 5 have on a the gap 7 facing side in each case an opening cross-section 16 in the gap 7 empties.

According to the 1 is the opening cross section 16 smaller than the cross section of the rest of the channel 11 , so that at the exit of the partial volume flows from the channels 11 there is a constriction that creates a nozzle effect. Accordingly, the channels own 11 a section 14 , in which the cross section is constricted. In the present case, the constriction occurs continuously over a height of the section 14 , Alternatively, a sudden constriction is conceivable. Furthermore, the section could also be formed by a ring which is attached to the outlet cross-section of the channel.

The equalization device 6 consists of two spaced apart, parallel sieves 17 , which at their two long sides each of a U-shaped strips 18 are edged so that the equalization device 6 in the 1 has a rectangular shape.

Finally, the device according to the invention has 1 out 1 an elongated, slightly funnel-shaped outlet 19 from which the uniformized air flow exits, for example, in a room to be ventilated. A cross section of the equalization device 6 , by which the volume flow the equalization device 6 leaves, is as air outlet cross section 22 Are defined.

From the 2 goes a three-dimensional view of the device according to the invention 1 out 1 only one half of which is shown and, for better illustration, partially depicting a side wall of the housing 10 was waived. The length L the device 1 is with a line 23 shown at the end dashed, which is intended to illustrate that the device 1 is longer than in the 2 shown. The three rows of passages 5 the beam generating device 4 are easy to recognize. Also the cross-sectional widening of the air duct 8th to the air distribution room 3 goes clearly out of the 2 out. By means of an arrow 24 the flow direction is within the half of the air distribution space shown 3 indicated, wherein the flow direction within the not shown half of the air distribution space 3 runs in the opposite direction, since the out of the air duct 8th outflowing air flow is divided on both sides.

The 3 shows an exemplary structure of the beam generating device 4 of which a three-dimensional bottom view is shown. The beam generating device 4 has a plate-shaped upper part 20 on, as an injection-molded component in one piece with the individual passages 5 is formed. The plate-shaped upper part 20 is folded up on both sides and thus has two side walls 21 , In the 3 show the channels 11 no section with constricted cross-section on. The sections can be dispensed with in applications with less stringent flow characteristics. With regard to the production of the jet-generating device, it is also conceivable that pipe sections are cut from standard pipes, which are widened on one side and then welded to a plate.

Alternatively, the beam generating device may also be formed by a plate into which corresponding passage openings are introduced.

A second example of a device according to the invention 1' goes out of the 4 which is a thick-walled pipe 25 shows that the air distribution space 3 ' surrounds or limits. For clarity, only a section of the pipe is 25 represented, which is formed in reality much longer and thus an elongated device 1' arises. The air duct for feeding the device 1' is not in the 4 shown, where this at any point of the tube 25 can be appropriate. It consists in the device 1' the possibility of the air duct in the radial direction to the pipe 25 on the other hand, it is also possible, the air duct parallel to the longitudinal axis 26 of the pipe 25 provide, so that the air duct on an end face of the tube, not shown 25 is appropriate. It is understood that the tube 25 is formed closed at both ends, to a closed Luftverteilraum 3 ' to obtain.

A section 27 of the pipe 25 is as a beam generating device 4 ' formed by the wall of the pipe 25 with passages 5 ' is provided, which is a radial to the pipe 25 extending longitudinal axis possess. The individual passages 5 ' are in terms of their cross-section and the division in inlet area 12 , Channel 11 and section 14 the channel with a smaller cross section analogous to the passage openings 5 from the 1 built up.

At a distance to the pipe 25 is on a lower side of a homogenizer 6 ' arranged in the form of a sieve, wherein the sieve to the pipe 25 has adapted curvature, so that the distance is the same at each point.

Alternatively, the device is conceivable 1' be modified such that the wall of the tube is circumferentially provided with openings and the equalization device is also formed as a tube, so that the air flow is discharged over the entire circumference of the tube or over the entire circumference of the equalization device in a room.

Finally, the shows 5 Longitudinal sections of three differently shaped passage openings 5 ' . 5 '' . 5 "" , whereby in each case the inlet area 12 " . 12 "' . 12 "" is formed differently. When in the 5 left illustrated passage 5 ' is the inlet area 12 " trumpet shape. When in the 5 in the middle represented passage opening 5 '' is the inlet area 12 '' trained and trained in the 5 Right entry port shown 5 "" has a funnel-shaped or frusto-conical inlet area 12 "" on. The ratio of the largest diameter of the inlet area 12 to the diameter of the channel 11 is each 2 ,

LIST OF REFERENCE NUMBERS

1, 1 '

contraption

2

arrow

3, 3 '

air distribution

4,4 '

Beam forming means

5, 5 ', 5 ", 5'", 5 ""

Through opening

6, 6 '

The equalizing device

7

gap

8th

air duct

9

Air inlet cross-section

10

casing

11

channel

12, 12 ", 12" ', 12 ""

inlet region

13

Inlet cross-section

14

Section of the canal

15

blocking surface

16

Opening cross-section

17

scree

18

strip

19

outlet

20

plate-shaped upper part

21

Side wall

22

Air outlet cross section

23

line

24

arrow

25

thick-walled pipe

26

longitudinal axis

27

Section of the pipe

28

arrow

H

height

B

width

L

length

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 2941276 A1 [0005]

Claims (12)

Device (1, 1 ') for expanding an air volume flow, comprising - an air distribution space (3, 3'), comprising - an air inlet cross section (9) for connection to an air duct (8) and - a beam generating device (4, 4 ') a plurality of passage openings (5, 5 ', 5 ", 5"', 5 ""), which together form an air passage cross section, - a gap (7) into which the passage openings (5, 5 ', 5 ", 5 ", 5"") open and - a homogenization device (6) through which the air flow from the intermediate space (7) passes out and on an opposite side of the space (7) defines an air outlet cross section (22), wherein the air outlet cross section (22 ) is substantially larger than the air inlet cross section (9) and the passage openings (5, 5 ', 5 ", 5"', 5 "") each from a the air distribution space (3) facing inlet region (12, 12 ", 12"' , 12 "") and a the space (7) facing channel (11) composed in which the air volume flow is in each case deflected in an inlet region (12, 12 ", 12"', 12 ""), characterized in that the inlet regions (12, 12 ", 12"', 12 "), from the air distribution chamber (3) viewed in the direction of the intermediate space (7) taper, trumpet-shaped, conical or stepped, wherein inlet cross sections (13) of the passage openings (5, 5 ', 5 ", 5'", 5 "") substantially within a common entry plane are located. Device after Claim 1 , characterized in that the inlet regions (12, 12 ", 12"', 12 "") and the respective corresponding channels (11) in a transitional cross section, in which the inlet region (12, 12 ", 12', 12"") into the channel (11) passes, have the same cross-section. Device after Claim 1 or 2 , characterized in that blocking surfaces (15) of the beam generating device (4), which are located between the inlet cross sections (13) of the passage openings (5, 5 ', 5 ", 5"', 5 ""), also substantially within the Entry level. Device according to one of Claims 1 to 3 , characterized in that - viewed in a cross section - tangents of a wall of the inlet regions (12, 12 ") coincide with the entry plane. Device according to one of Claims 1 to 4 , characterized in that in each case a largest diameter of the inlet regions (12, 12 ", 12 ', 12"") is at least greater than 2 times, preferably greater than 2.5 times, a diameter of the corresponding channels (11 ). Device according to one of Claims 1 to 5 , characterized in that a passage cross section of the beam generating device (4, 4 ') is smaller than 0.5 times, preferably as the 0.4 times, more preferably smaller than 0.25 times, the air inlet cross section (9) the air distribution space (3, 3 '). Device according to one of Claims 1 to 6 , characterized in that a ratio of a length of each of a channel (11) to a diameter of the channel (11) is at least 2, preferably at least 3, more preferably at least 5. Device according to one of Claims 1 to 7 , characterized in that the channels (11) have on a side facing the intermediate space (7) a section (14) in which a cross section is smaller than the cross section in the region of the remaining channel (11). Device according to one of Claims 1 to 8th , characterized in that the passage openings (5, 5 ', 5 ", 5"', 5 "") are formed by pieces of pipe which are widened at one end. Device after Claim 8 or 9 , characterized in that inlet area walls in the region of the inlet cross sections (13) of the inlet regions (12, 12 ", 12", 12 "") are connected to a plate-shaped upper part (20) of the jet generating device (4), preferably made of metal and with the welded plate-shaped upper part (20), or integrally with the plate-shaped upper part (20) of the jet generating means (4) are formed, preferably as an injection-molded component or die-cast component. Device according to one of Claims 1 to 10 , characterized by a clear distance between the beam generating means (4, 4 ') and the equalization means (6, 6'), which is three to ten times the diameter of a channel (11). Device according to one of Claims 1 to 11 , characterized in that the equalization means (6, 6 ') comprises a sieve (17), a perforated plate or a porous material, preferably several of which are arranged one behind the other.

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