WO1999041507A1

WO1999041507A1 - Tubular air diffuser

Info

Publication number: WO1999041507A1
Application number: PCT/FI1999/000072
Authority: WO
Inventors: Juha Järvinen
Original assignee: ABB Fläkt Oy
Priority date: 1998-02-13
Filing date: 1999-02-02
Publication date: 1999-08-19
Also published as: FI980334A0; WO1999041507A8; AU2425599A; FI109307B; FI980334A

Abstract

The invention relates to a tubular air diffuser (1) for distributing supply air into a room or similar space, said diffuser envelope having a plurality of openings made thereto with a diameter substantially smaller than the diameter of said tubular diffuser, each of said openings having a separate nozzle (2) adapted thereto for passing supply air into the room space from the diffuser. The invention is implemented by providing each one of said nozzles (2) with at least two air discharge orifices (3) that are oriented in different directions with respect to each other.

Description

Tubular air diffuser

The present invention relates to a tubular air diffuser for distributing supply air into a room or similar space, said diffuser envelope having a plurality of openings made 5 thereto with a diameter substantially smaller than the diameter of said tubular diffuser, each of said openings having a separate nozzle adapted thereto for passing supply air into the room space from the diffuser.

The ventilation air streams in room spaces are actively controlled by air o conditioning systems, implemented by bringing fresh outside air into the room space via suitably designed grilles, valves or similar air diff users and, respectively, removing the stale, heated or excessively moist air formed in the room space out therefrom by means of separate outlet air equipment. In air conditioning, fresh air is introduced into the room space via the air diffuser elements as a single stream or s in a plurality of streams that are discharged in a desired direction deep into the interior of the room space, typically into the upper portion thereof. By virtue of induction, the air streams capture the surrounding air and mix therewith so that resultingly the room space will be conditioned with a maximally homogenous mixture of the supplied outside air with the room air so that the conditioned room o air almost everywhere has an almost constant temperature, impurity distribution, moisture content and other parameters.

The present invention is related to essentially tubular air dif fusers having a plurality of small discharge openings. Such air dif fusers are disclosed, e.g., in FI Pat. 5 No.79,608 and FI Pat. Appl. No.965,190. ATI these prior-art diffuser devices are characterized in that the surface of the air diffuser is provided with a plurality of air discharge openings having a diameter much smaller than the diameter of the tubular diffuser, said openings being delineated from the diffuser envelope by nozzles extending outward from the envelope. In practice, the nozzles are formed o from the same material as the diffuser envelope. They may be made by punching, for instance. In the art are also known tubular air diffuser devices in which the nozzles are formed by separate nozzle parts inserted in the air discharge openings. Each one of such nozzle parts has a single orifice through which air flows. The orifices have a straight bore oriented radially outward from the tubular diffuser device.

It is an object of the present invention to provide improvements into the above- described type of air diffuser devices. It is a particular object to reduce the emitted noise level of the diffuser and to improve the induction effect in the mixing of inlet air in the room space. Furthermore, the radially outward protruding nozzles of prior- art diffusers that are not particularly pleasing in the external appearance of the diffuser device have been avoided.

The diffuser device according to the invention is characterized in that each one of the air discharge nozzles has two or a greater number of orifices oriented in different directions with respect to each other.

A preferred embodiment of the diffuser device according to the invention is characterized in that the cross section of the air discharge nozzle orifices is tapered in the discharge direction of air flow.

Another preferred embodiment of the diffuser device according to the invention is characterized in that the cross section of the air discharge nozzle orifices is tapered essentially smoothly, e.g., conically in the discharge direction of air flow.

A still another preferred embodiment of the diffuser device according to the invention is characterized in that each one of the nozzles has four air discharge orifices displaced essentially equidistantly and oriented in different directions with respect to each other so as to form a fanned array of orifices.

By virtue of the invention, the induction effect of the tubular diffuser device is improved thus achieving better mixing of inlet air discharged into the room space inasmuch the shape and orientation of the inlet orifices cause a vorticose air mixing. The tubular air diffuser according to the invention has been found to emit less noise which means a significant improvement in the art. Moreover, the look of the diffuser is more pleasing to the eye, because the nozzles need not protrude outward from the external surface of the diffuser toward the room space.

5

In the following the invention will be examined in greater detail with the help of an exemplifying embodiment by making reference to the appended drawings, in which

Figure 1 shows a portion of a tubular air diffuser device having a number of nozzles i o according to the invention adapted to its envelope;

Figure 2 shows an enlarged detail C of Fig.1;

Rgure 3 shows a nozzle part according to the invention with the arrangement of its 15 air flow channels;

Figure 4 shows a sectional view taken along line A-A of fig.3; and

Figure 5 shows a sectional view taken along line B-B of Rg.3.

20

In Fig.1 is shown a portion of a tubular air diffuser device 1 whose envelope is provided with air discharge openings having nozzle parts 2 mounted therein. The number and location of the openings (and nozzles as well) can be varied as required. As mentioned above, detail G is shown in Rg.2 in an enlarged scale. This 25 detail illustrates from the nozzle part the surface that will remain visible on the external side of the diffuser device. In this exemplifying embodiment, the nozzle part 2 is provided with four air discharge orifices 3 that are displaced essentially equidistantly from each other. While the number of air discharge orifices is not limited, their number must be at least 2.

30

In Rg.3, the arrangement and shape of the air discharge orifices 3 is shown in greater detail. As is evident from the diagram, each air discharge orifice is made smoothly, e.g.. conically, tapering in the air flow direction. Simultaneously as the discharge orifice channels taper toward their exit ends, they are directed in a fanned shape about the nozzle part center axis which in fig.3 is located in the center of the nozzle part, perpendicular to the plane of the drawing. The surface of 5 the nozzle part 2 shown in fig.2 is the external surface louter face) in which the cross sections of air discharge orifices reach their minimum values. On the internal surface of the nozzle part, which is located in the interior of the diffuser device as shown in Fig.3, the location and size of the air discharge orifice channels are drawn as larger circles. At their inlet ends in the interior of the diffuser device, the cross- o sectional diameter of the air discharge orifice channels is about 3-5 mm, most advantageously about 4 mm, and at their outlet ends on the external surface of the diffuser device, about 1.5-3.5 mm, most advantageously about 2.5 mm.

In fig.3 are also shown some dimensional design details related to this 5 exemplifying embodiment. Advantageously, the following values can be used for dimensions denoted by reference letters O-K:

0 = 2.5 mm, E = 3.0 mm, F = 2.5 mm, G = 3.0 mm H = 2.5 mm, I = 3.0 mm, J = 2.5 mm, K = 3.0 mm. 0

In fig.4 is shown a sectional view taken along line A-A of fig.3 and in fig.5 along line B-B, respectively. As is evident from these diagrams, the nozzle part 2 is comprised of an essentially cylindrical body part 2', which is otherwise a solid piece with the exception of the air discharge orifice channels 3 made thereto, and of a mounting 5 part 2" of smaller diameter serving to attach the nozzle part 2 to a hole made on the diffuser device 1. To assure positive attachment of the nozzle part, the outer diameter of said latter, smaller-diameter nozzle part 2" is made essentially equal to the diameter of the hole made on the diffuser device 1 except for the end of said smaller-diameter nozzle part 2" whose outer perimeter is provided with a collar 4 o which can be pushed from the internal side of the diffuser device outward through said hole of the diffuser envelope so as to snap-lock the nozzle part 2 in place. Thus, a major part (that is, the body part 2 ) of the nozzle part 2 remains concealed in the interior of the diffuser device 1. Hence, the mounting of the nozzles must be made prior to the forming of the tubular diffuser device into its cylindrical shape. This technique is easy to implement inasmuch ventilation ducts are conventionally 5 made from sheet metal band which is paid off from coil and wound/seamed into tubular form.

To those versed in the art it is obvious that the invention is not limited by the exemplifying embodiments described above, but rather, can be varied within the l o scope and spirit of the appended claims.

Claims

Claims:

1. Tubular air diffuser (1) for distributing supply air into a room or similar space, said diffuser envelope having a plurality of openings made thereto with a diameter

5 substantially smaller than the diameter of said tubular diffuser, each of said openings having a separate nozzle (2) adapted thereto for passing supply air into the room space from the diffuser and each one of said nozzles (2) having at least two air discharge orifices (3) made thereto, characte rize d in that said air discharge orifices (3) are oriented in different directions with respect to each o other.

2. Diffuser according to claim 1, c h a ra c terize d in that the cross section of the air discharge nozzle orifices (3) is tapered in the discharge direction of air flow.

5 3. Diffuser according to claim 2, c h a ra cterize d in that the cross section of the air discharge nozzle orifices (3) is tapered essentially smoothly, e.g., conically in the discharge direction of air flow.

4. Diffuser according to any of claims 1-3, c h aracterize d in that each one of o the nozzles has four air discharge orifices (3) displaced essentially equidistantly and oriented in different directions with respect to each other so as to form a fanned array of orifices.

5. Diffuser according to claim 4, characterize d in that at their inlet ends in the 5 interior of the tubular diffuser device (1), the cross-sectional diameter of the air discharge orifices (3) is about 3-5 mm, most advantageously about 4 mm, and at their outlet ends on the external surface of the tubular diffuser device (11, about 1.5-3.5 mm, most advantageously about 2.5 mm.

0 6. Diffuser according to claim 4 or 5, characterized in that in the interior of the diffuser device (1), the ends of the longitudinal axes of said air discharge orifices (3) are arranged more outdistanced from the center axis of said nozzle part (2) than at the opposite ends of said air discharge orifices, thus making the axes of the orifice channels to converge toward the center axis of the nozzle part in the discharge direction of air flow.

7. Diffuser according to any of claims 1-6, cha ra cterize d in that the nozzle part (2) is comprised of an essentially cylindrical body part (21, which is otherwise a solid piece with the exception of the air discharge orifice channels made thereto, and of a smaller-diameter mounting part (2") serving to attach the nozzle part (2) to a hole made on the diffuser device.

8. Diffuser according to claim 7. c h a ra cte rize d ╧è╧Ç that the outer diameter of said latter, smaller-diameter nozzle part (2") is made essentially equal to the inner diameter of the hole made on the diffuser device (1) except for the end of said smaller-diameter nozzle part (2") whose outer perimeter is provided with a collar (4) which can be pushed from the internal side of the diffuser device outward through said hole of the diffuser device so as to snap-lock the nozzle part (2) in place.