Device for adjusting an air volumetric flow rate

Abstract

The invention relates to a device for adjusting an air volumetric flow rate, in particular in an air distribution network, comprising a central air channel (24) with a cross-section through which air can flow and a throttle (6) located in the central air channel (24). The cross-section (70) through which air can flow is variable by means of the throttle (6). An internal flow element (3) comprises a sheath (30), the periphery of which expands in the direction away from the throttle (6). The central air channel (24) has, in the region of the flow element, a taper (251) and a subsequent re-expansion (252). This leads to a curved flow channel (8) between the sheath (30) of the internal flow element (3) and the re-expansion (252) which ends at an outer face of the device. The device according to the invention allows simple adjustability of the volumetric flow rate, simple measurement of the volumetric flow rate and, when used as a supply-air valve, optimal flow distribution.

Description

[0001] TITLE

[0002] Device for adjusting an air volume flow

[0003] TECHNICAL FIELD

[0004] The present invention relates to a device for adjusting an air flow, in particular an air supply valve or an exhaust air valve.

[0005] STATE OF THE ART

[0006] Air distribution networks are used primarily in buildings for ventilation and, in some cases, for air conditioning. Controlled residential and office ventilation systems are now sophisticated systems that utilize centralized or decentralized ventilation units.

[0007] The wall, ceiling, or floor openings of a building have air vents with inserts connected to the air distribution network. Such air vents change the shape of the airflow and / or regulate the airflow volume. Some of the inserts allow the airflow volume to be adjusted. They are called supply air valves or exhaust air valves, depending on the direction of the airflow into or out of the room. They limit the cross-section in the air duct, and the size of this limit is partially selectable.

[0008] Supply air vents, i.e., vents through which air flows into a room, often have the disadvantage of not distributing the outgoing air evenly. A seated or lying person directly exposed to the outgoing air may find this unpleasant.

[0009] Exhaust air valves, i.e., valves through which air flows out of a room, often have a different shape than supply air valves, resulting in a rather cluttered appearance in the room. Furthermore, such supply air and exhaust air valves are often impossible to adjust once installed, or can only be adjusted with relatively great effort. A further disadvantage is that individual components of the valve protrude into the room to varying degrees depending on the valve's adjustment, protruding from the building wall and impairing the visual appearance of the room.

[0010] WO 2022 / 101056 A1 discloses an air volume throttle valve with air guide elements in the form of rotor blades. The air guide elements are each formed from a first and a second air guide unit, which can be rotated relative to each other, so that the distance between the air guide elements and thus the flow-through cross-section of an air duct can be varied. This device enables the free flow cross-section to be varied while maintaining the position of the narrowest flow cross-section. This facilitates valve control.

[0011] PRESENTATION OF THE INVENTION

[0012] It is therefore an object of the invention to provide an improved device for adjusting a volume flow.

[0013] This object is achieved by a device having the features of patent claim 1.

[0014] The device according to the invention for adjusting an air volume flow, in particular in an air distribution network, has a central air duct with a flow-through cross-section and a throttle arranged in the central air duct, wherein the flow-through cross-section can be varied by means of the throttle. The device further has an inner flow element with a casing whose circumference increases in the direction away from the throttle. The central air duct has a taper in the region of the flow element and a subsequent further widening. This creates a curved flow channel between the casing of the inner flow element and the further widening, which ends on an outer side of the device. The taper is preferably located at a distance from the throttle.

[0015] The separation of the inner flow element and the throttle, as well as the inventive design of the central air channel in the area of ​​the inner flow element, enable the creation of a flow channel whose flow cross-section remains unchanged when the throttle setting is changed. Depending on the design, the flow cross-section of the flow channel is either constant over its entire length or changes along the flow direction. The tapering and subsequent widening positively influence the flow distribution.

[0016] The constant flow cross-section is usually directed away from the throttle and toward the building interior. In the case of a supply air valve, this is the outflow or exhaust cross-section. In the case of an exhaust air valve, this is the air inlet cross-section.

[0017] The device according to the invention has several advantages:

[0018] - Since the flow cross-section in the area facing the interior of the building remains unchanged, even if the throttle setting is changed, the visual appearance of the room also remains essentially or completely unchanged.

[0019] - Furthermore, the constant flow cross-section simplifies the measurement of the volume flow, since a clear assignment of an aerodynamic force or another measured variable proportional to the flow velocity is possible depending on the volume flow.

[0020] - The separation also allows for the device to be designed independently of the shape of the throttle in the area of ​​the inner flow element. In the case of a supply air valve, the airflow distribution into the building space is optimized.

[0021] - Sound-damping optimized shapes can also be created in a simpler way.

[0022] In the device according to the invention, the inner flow element widens toward the building interior. The central air duct tapers and widens again, creating a curved flow channel between the inner flow element and the extension. This results in a supply air valve with an air flow that is deflected in a radial direction.

[0023] The device preferably comprises a housing that forms the central air channel and has an inner wall that forms the taper and the further widening. The housing is preferably substantially circular-cylindrical. The housing preferably comprises a circumferential first guide surface, a circumferential second guide surface, and a projection located therebetween. The first guide surface preferably faces the throttle, and the second guide surface preferably runs parallel to the outer casing of the inner flow element. This design enables an easily assembled valve with optimized flow guidance, in particular thanks to the special design of the inner wall of the substantially circular-cylindrical housing.

[0024] The curved flow channel preferably has a cross-section that remains constant regardless of the throttle setting. On the one hand, this improves the visual appearance, as the valve always looks the same. Furthermore, there are more options for placing a sensor element for determining the volume flow. Since the flow channel extends over a significant length, the radial deflection of the outflow is optimized.

[0025] The sensor element for determining the volume flow is preferably a disruptive body which is introduced into the outflow channel or, in the case of an exhaust air valve, into the inflow channel and around which the air flows.

[0026] An optimal, homogeneous, radially flowing outflow is achieved when the inner flow element is bell-shaped. Thanks to the Coanda effect, the outgoing or outgoing air flows along the convex surface and is thus distributed along the wall surface. This prevents unpleasant air currents directed directly downwards from the ceiling.

[0027] The radial distribution of the outflow is further increased if the extension has a bell-shaped inner wall.

[0028] The flow channel defined by the inner wall and the bell-shaped flow element preferably has a cross-sectional area along its entire length that remains constant when the throttle setting is changed. This not only facilitates volume flow measurement but also minimizes any flow noise, since the air channel facing away from the throttle can be designed as a downstream, sound-damping element.

[0029] In preferred embodiments, the inner flow element is stationary. In other embodiments, it is at least stationary with respect to the axial direction and / or at least stationary with respect to the tapering and further widening. This also improves the appearance because the flow element, and thus all components of the valve, always protrude the same distance into the chamber.

[0030] An advantage is that exhaust air valves can be designed in the same way as supply air valves without any geometric adjustments. They can be completely identical or they can differ in the shape of the throttle, since this is hardly or not visible from the outside when installed.

[0031] The advantage is that a room with multiple valves maintains a uniform appearance, even if the valves' flow volumes are set differently. For this reason, supply air valves and exhaust air valves are preferably designed identically, at least except for the shape of the throttle.

[0032] Preferably, the casing of the flow element and / or the taper and / or the further widening are rotationally symmetrical. This optimizes the distribution of the outflowing air flow. Preferably, the curved flow channel is annular.

[0033] In preferred embodiments, the device comprises a housing that forms the central air duct and has an inner wall that forms the tapered portion and the further widened portion. The device can thus be manufactured cost-effectively and designed to be compact.

[0034] In preferred embodiments, a measuring unit for determining the volume flow is provided. The measuring unit is preferably arranged in the region of the constant flow cross-section, i.e., in the flow channel.

[0035] In preferred embodiments, the measuring unit has a sensor element arranged in the flow channel. This facilitates the determination of the volume flow. V = v x A, where A is the constant cross-section of the flow channel. Thus, a force acting on the sensor element or another physical measurement variable is proportional to the velocity v and thus to the volume flow V.

[0036] The measuring unit can thus be designed simply and cost-effectively. Well-known sensors for velocity measurement, such as a hot-wire anemometer, can be used. Preferably, a spring-loaded perturbation element exposed to the flow is used. A restoring force generated by a spring mechanism makes it possible to equate the deflection of the spring with the aerodynamically applied force, thus calculating the volume flow.

[0037] Preferably, the inner flow element has a through-opening extending from the throttle to a side opposite the throttle. This design has several advantages.

[0038] On the one hand, the measuring unit can be mounted in a space-saving manner within the inner flow element. Furthermore, a display can be arranged within this space, preferably in an intermediate level, to read the current flow rate. This can be achieved, for example, using a mechanical pointer that moves along a scale according to the current flow rate.

[0039] On the other hand, the throttle can be adjusted via the through-hole when the device is installed. This can be achieved, for example, with a screwdriver, an Allen key, or another hand tool that is guided through the through-hole to an adjustment mechanism of the throttle. Alternatively or additionally, the throttle has a rotary device that allows manual adjustment. The rotary device is preferably located on the second throttle part. The flow rate can thus be changed quickly and easily.

[0040] In further embodiments, both the measuring unit and the throttle adjustment are electrically designed so that an automated adjustment according to a setpoint can be carried out using a controller in this interior

[0041] Another advantage is that the flow rate scale and the throttle adjustment mechanism are both accessible via the through-hole. This makes it easier to adjust the valve to the desired flow rate.

[0042] Preferably, the through-opening can be repeatedly closed and uncovered by means of a cover when the device is installed. The cover can preferably be removed and reattached without tools. Thanks to the cover, the visual appearance of the room is improved. The cover surface is preferably approximately flush with the building wall or ceiling. The inner flow element is thus preferably closed flush with the ceiling. The cover surface is preferably designed to match the building wall and is preferably flat. The throttle is preferably adjustable by means of a rotary mechanism.

[0043] In preferred embodiments, the throttle has blades that can be rotated relative to one another to change the flow cross-section. The throttle is preferably designed with multiple blades to improve the flow rectification effect.

[0044] In one embodiment, the throttle is designed according to WO 2022 / 101056 A1. In other embodiments, it is also rotor-shaped, but has different components. Alternatively, the throttle is an orifice plate or another unit for changing a cross-section. In preferred embodiments, however, the throttle always has curved inflow surfaces that form an aerodynamically favorable body. This behavior is enhanced by the fact that the outer contour of the throttle element or throttle disc, in the unthrottled state, adapts to the shape of the rigid throttle element and thus completely or almost completely merges into it.

[0045] In preferred embodiments, the throttle can be adjusted manually. In other embodiments, the throttle can be adjusted, preferably even regulated, by a motor as an alternative or in addition to manual adjustment.

[0046] Further embodiments are specified in the dependent claims.

[0047] BRIEF DESCRIPTION OF THE DRAWINGS

[0048] A preferred embodiment of the invention is described below with reference to the drawings, which are for illustrative purposes only and are not to be construed as limiting. In the drawings:

[0049] Figure 1 shows a longitudinal section through a device according to the invention, installed in a wall;

[0050] Figure 2 is a perspective view of the device according to Figure 1 from below;

[0051] Figure 3 is an exploded view of the device according to Figure 1 from above; Figure 4 is an exploded view of the device according to Figure 1 from below;

[0052] Figure 5 is a perspective view of the device according to Figure 1 from above in a first position of the throttle and

[0053] Figure 6 is a perspective view of the device according to Figure 1 from above in a second position of the throttle.

[0054] DESCRIPTION OF PREFERRED EMBODIMENTS

[0055] Figure 1 shows a valve V according to the invention, which is installed in a wall opening 10 of a wall 11. The wall opening 10 is preferably part of an air distribution network of a building.

[0056] The valve V is an exhaust air valve which directs air from a building room into the wall opening 10 or it is a supply air valve which directs air from the air distribution network through the wall opening into the building room.

[0057] In the following, valve V is described as a supply air valve, although its function is identical to that of an exhaust air valve.

[0058] The valve V has a housing 2, which is held in the wall opening 10. For this purpose, it preferably has a circumferential first flange 21, preferably in the form of a flexible sealing and / or clamping ring.

[0059] An inner flow element 3 is arranged in the housing 2 and extends toward the building interior. The inner flow element 3 is preferably formed with a through-opening and closed with a cover 5. In this example, the inner flow element 3 is essentially hollow with an intermediate ceiling having a centered hole. Thus, a through-opening extending from the throttle to the end facing the building interior is provided.

[0060] Preferably, a measuring unit 4 for determining a volume flow is arranged in the inner flow element 3. A sensor element 41 of the measuring unit 4 projects into a flow channel 8. The flow channel 8 is formed between the inner flow element 3 and an inner wall of the housing 2.

[0061] In the upper area, i.e., facing away from the interior of the building, a throttle 6 is arranged on the housing 2. The inner flow element 3 is preferably attached to the throttle 6.

[0062] The throttle 6 has adjustable means for selectively narrowing a central air duct 24. The central air duct 24 is clearly visible in Figure 3. It is defined by the inner diameter of the housing 2. Its flow-through cross-section is defined by those areas of the central air duct 24 through which the air flow can flow. This flow-through cross-section can be varied by means of the throttle 6.

[0063] Following the throttle 6 in the flow direction, i.e., toward the building interior, the flow-through cross-section of the central air duct 24 can no longer be changed. It tapers and then widens again. This can be achieved by inserting it into the housing 2. Preferably, however, the inner wall of the housing 2 is correspondingly curved, as shown here.

[0064] The inner wall forms an upper, circumferential first guide surface 250, which faces the throttle 6. This surface terminates in a circumferential projection 251 directed toward the flow element 3. The projection 251 is followed by a lower, circumferential second guide surface 252. The second guide surface 252 is inclined with respect to the longitudinal axis L. Preferably, it is convex, i.e., it curves toward the longitudinal axis L.

[0065] The outer shell 30 of the inner flow element 3 runs parallel to the second guide surface 252. Together, they form the flow channel 8, which has a cross-sectional area along its length that does not change when the throttle setting is changed, i.e., remains constant. However, depending on the design, the cross-sectional area can change along the flow direction. In particular, the cross-sectional area of ​​the outlet opening of the valve V remains unchanged, regardless of the change in the flow-through cross-section in the area of ​​the throttle 6.

[0066] Preferably, the outer shell 30 is bell-shaped, and preferably the second guide surface 252 is the negative image of the corresponding bell shape. The valve V is preferably arranged flush with the surface of the wall 11 or protrudes only slightly, as can be seen in Figure 1. A change in the flow-through cross-section by means of the throttle 6 does not lead to any changes in the outflow-side region of the valve V. This means that the axial position of the inner flow element 3 does not change. Its position relative to the wall 11 thus remains unchanged. As already mentioned, the outflow cross-section of the flow channel 8 also does not change.

[0067] The individual components of the valve V according to the invention are clearly visible in Figures 2 to 6. The exploded views in Figures 3 and 4 show the individual components from two perspectives.

[0068] The housing 2 is essentially circular-cylindrical in shape. It comprises a first housing portion 20 with tabs 200 directed upward toward the throttle 6, and a second housing portion 22. The circumferential first flange 21 is arranged between them. It can be overmolded, integrally formed, or attached to the rest of the housing 2 in another way.

[0069] A second flange 23, which is preferably rigid, is formed at the lower end of the housing 2. It serves as a stop when inserting the valve V into the wall opening 10, as can be seen in Figure 1. It forms a seal to cover irregularities in the surrounding wall 11.

[0070] In this example, throttle 6 is designed with rotor-like blades. As mentioned above, it can also be designed in a different way.

[0071] The throttle 6 shown here has a first throttle part 60, a second throttle part 61, and a third throttle part 62. The second throttle part 61 is rotatable relative to the first and third throttle parts 60, 62 about a longitudinal axis L of the valve. The first and second throttle parts 60, 62 are connected to one another in a rotationally fixed manner.

[0072] The first throttle part 60 has a central first hub part 600 and at least three first vanes 601 extending radially therefrom. In this example, there are exactly three vanes 601. Lugs 602 are formed on the end faces of the free ends of the first vanes 601, which engage with the tabs 200 of the housing 2, so that the first throttle part 60 is connected to the housing 2 in a rotationally fixed manner.

[0073] The first throttle part 60 has downwardly projecting hooks 603 that extend through curved, elongated, peripheral through-openings 613 in a second hub part 610 of the second throttle part 61 and engage in receiving openings 622 of a third hub part 620 of the third throttle part 62. As a result, the first vanes 601 lie congruently over third vanes 621 of the third throttle part 62. They preferably each form curved surfaces, in particular curved inflow surfaces.

[0074] The intermediate second throttle part 61 has the same number of second vanes 611, which extend radially from the second hub part 610. In contrast to the first and third vanes 601, 621, the second vanes 611 are preferably flat. They can be rotated relative to the first and third vanes 601, 621, so that the flow-through openings 70 between the vanes of the throttle change in size. This is clearly illustrated in Figures 5 and 6.

[0075] In Figure 5, the second vanes 611 are noticeably rotated relative to the first and third vanes 611, 621. The passage openings 70 and thus the variable, flow-through cross-section of the valve V are relatively small. In Figure 6, the second vanes 611 are congruent with the first and third vanes 601, 621, so that the passage openings 70 and thus the variable, flow-through cross-section of the valve V are maximized. The passage openings 70 thus define the variable, flow-through cross-section of the valve V.

[0076] Preferably, snap hooks 612 or other haptic elements are provided which, on the one hand, provide feedback to the operator when manually adjusting the throttle and, on the other hand, hold the twisted second wings 611 in their position.

[0077] Preferably, an end stop 604 is provided for every second wing 611. In this example, the end stops 604 are downwardly projecting side walls on the first wings 601.

[0078] A downwardly projecting adjustment sleeve 614 is located centrally on the underside of the second hub part 610. This is accessible from the side of the valve facing the building wall 11, so that the second throttle part 61 can be rotated using a hand tool, e.g., an Allen key. The inner flow element 3 is attached to the throttle 6. It is preferably connected to it by means of snap elements 623. The snap elements 623 can be seen in Figures 1 and 3.

[0079] The inner flow element 3 has a bell-shaped casing 30 that widens away from the throttle 6. The outer surface of the casing 30 is preferably flat, i.e., smooth. The flow element 3 has a lowermost end face 31, which is preferably planar. The flow element 3 is essentially hollow and open on both ends. This provides external access to the adjusting sleeve 614 of the throttle 6.

[0080] The measuring unit 4 is arranged in the cavity of the inner flow element 3. It comprises a spiral spring 40, a sensor element 41 in the form of a pointer, and a scale 42. The sensor element 41 is connected to the spiral spring 40 at a first end, and its opposite second end projects from the flow element 3 into the flow channel 8. For this purpose, the flow element 3 has a corresponding elongated hole 300 in the casing 30, which can be seen in Figure 4. The scale 42 is fixed in the cavity, facing downwards so that it is easily visible to the user when installed. It is preferably attached to the underside of the false ceiling 32. Depending on the air flow flowing through the flow channel 8, the position of the sensor element 41 and thus of the pointer changes with respect to the scale 42. The air volume can thus be read directly or at least calculated.Depending on the design of scale 42, only the change in air volume can be detected.

[0081] The measuring unit 4 shown is merely one of several possible variants. In another embodiment, the sensor element is rotatably mounted on the wall of the flow element. A coil spring is arranged between the wall and the sensor element, generating the corresponding restoring force. The tip of the sensor element, in turn, points to a scale. In this example, the scale is preferably a component separate from the flow element, but still located in the cavity of the flow element.

[0082] In another embodiment, the sensor element is mounted so that it can be displaced linearly relative to the flow element and moves along a straight scale. The restoring force is again provided by a coil spring.

[0083] The valve V further comprises the cover 5 for closing the lower access opening of the inner flow element 3. It is clearly visible in Figures 3 and 4. It preferably comprises a flat, round base plate 50 with a preferably flat outer surface 51. On the opposite side, the base plate 50 has upwardly projecting ribs 52 for clamping the cover 5 into the second flange 31 of the inner flow element 3.

[0084] The cover 5 can be removed to adjust the throttle 6 and to determine the current flow rate using the scale. This is clearly visible in Figure 2.

[0085] The device according to the invention enables easy adjustment of the volume flow, easy measurement of the volume flow and, when used as a supply air valve, optimal flow distribution.

[0086] LIST OF REFERENCE SYMBOLS

[0087] Wall opening

[0088] Wall 6 throttle

[0089] 60 first throttle part

[0090] Housing 600 first hub part first housing area 601 first wing

[0091] Tab 602 Nose first flange 603 Hook second housing area 604 End stop second flange 61 second throttle part central air duct 610 second hub part first guide surface 611 second vane

[0092] projection 612 snap hook second guide surface 613 peripheral

[0093] Through hole inner flow element 614 adjusting sleeve

[0094] Coat

[0095] Slot 62 third throttle part

[0096] Front side 620 third hub part

[0097] Mezzanine level 621 third wing

[0098] 622 receiving opening

[0099] Measuring unit 623 snap element

[0100] spiral spring

[0101] Sensor element 70 passage opening

[0102] scale

[0103] 8 flow channel

[0104] Lid

[0105] Base plate V valve

[0106] Frontal area L Longitudinal axis

[0107] rib

Claims

PATENT CLAIMS 1. Device for adjusting an air volume flow, in particular in an air distribution network, wherein the device has a central air duct (24) with a flow-through cross-section and a throttle (6) arranged in the central air duct (24), wherein the flow-through cross-section (70) can be changed by means of the throttle (6), characterized in that the device further has an inner flow element (3) with a jacket (30), the circumference of which increases in the direction away from the throttle (6), and that the central air duct (24) has a taper in the region of the flow element (251) and a subsequent renewed widening (252), whereby a curved flow channel (8) is formed between the casing (30) of the inner flow element (3) and the renewed widening (252), which ends towards an outer side of the device.

2. Device according to claim 1, wherein the device comprises a housing (2) which forms the central air duct (24) and which has an inner wall which forms the taper (251) and the further widening (252).

3. Device according to claim 2, wherein the housing (2) is substantially circular-cylindrical.

4. Device according to one of claims 2 or 3, wherein the housing (2) has a circumferential first guide surface (250), a circumferential second guide surface (252) and a projection (251) located therebetween.

5. Device according to claim 4, wherein the first guide surface (250) faces the throttle (6).

6. Device according to one of claims 4 or 5, wherein the second guide surface (252) runs parallel to the outer shell (30) of the inner flow element (3).

7. Device according to one of claims 2 to 6, wherein the housing (2) can be clamped in a wall or ceiling opening.

8. Device according to one of claims 1 to 7, wherein it can be arranged flush with or only slightly protruding from a surface of a wall or ceiling.

9. Device according to one of claims 1 to 8, wherein the flow channel (8) has a cross-section over its length which remains unchanged when the setting of the throttle is changed.

10. Device according to one of claims 1 to 9, wherein the inner flow element (3) widens in a bell shape.

11. Device according to one of claims 1 to 10, wherein the renewed extension (252) has an inner wall which widens in a bell shape.

12. Device according to one of claims 1 to 11, wherein the inner flow element (3) remains stationary in the axial direction of the device with respect to the taper (251) and the renewed widening (252) when the flow-through cross-section (70) changes.

13. Device according to one of claims 1 to 12, wherein the jacket (30) of the flow element (3) and / or the taper (251) and / or the further widening (252) are rotationally symmetrical.

14. Device according to one of claims 1 to 13, wherein the device comprises a housing (2) which forms the central air duct (24) and which has an inner wall which forms the taper (251) and the further widening (252).

15. Device according to one of claims 1 to 14, wherein a measuring unit (4) is provided for determining the volume flow.

16. Device according to claims 9 and 15, wherein the measuring unit (4) has a sensor element (41) arranged in the flow channel (8).

17. Device according to one of claims 1 to 16, wherein the inner flow element (3) has a through-opening extending from the throttle (6) to to a side opposite the throttle (6).

18. Device according to claims 17 and optionally 15 or 16, wherein the measuring unit (4) is fastened in the inner flow element (3).

19. Device according to one of claims 17 or 18, wherein the throttle (6) is adjustable in the installed state of the device via the access opening for the purpose of changing the flow-through cross-section (70).

20. Device according to one of claims 17 to 19, wherein the access opening in the installed state of the device can be repeatedly closed and exposed by means of a cover (5).

21. Device according to one of claims 1 to 20, wherein the throttle (6) has blades (601, 611, 621) which can be rotated relative to one another in order to change the flow-through cross-section (70).

22. Device according to one of claims 1 to 21, wherein the throttle (6) has curved inflow surfaces.

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