EP0354949B1

EP0354949B1 - Air distribution unit

Info

Publication number: EP0354949B1
Application number: EP89902262A
Authority: EP
Inventors: Teuvo Pellinen
Original assignee: Halton Oy
Current assignee: Halton Oy
Priority date: 1988-02-19
Filing date: 1989-02-13
Publication date: 1993-06-16
Anticipated expiration: 2009-02-13
Also published as: FI880799A; DE68907148T2; DE68907148D1; FI880799A0; WO1989007739A1; EP0354949A1

Abstract

The present invention concerns an air distribution unit (10), comprising an external envelope (11) and an air inlet duct (12), and outlet duct (17). From the inlet duct (12) the air is disposed to flow into a sound absorption chamber (13), said sound absorption chamber (13) comprising an obliquely positioned sound absorption surface, advantageously a sound absorption plate (14), that the air after entering the air absorption chamber (13) flows in a space of the sound absorption chamber (13), tapering in cross-section (I-I), and flows from the air absorption chamber (13) into the air outlet chamber (15) of the air distribution chamber (13), and hereby changes its flow direction for at least 90°, substantially over 90°.

Description

The present invention concerns an air distribution unit.
DK 85412 discloses an air distribution unit in which air flows through a sound absorption chamber having a sound absorption plate and in which the air flow changes its flow direction through at !east 90° on entering an outlet chamber.
FI 73068 shows a terminal device for incoming air comprising an air inlet duct and an air outlet duct. The air meets an oblique sound absorption surface in the inlet air means. A useless space remains in the area behind the oblique sound absorption surface. The sound absorption capacity is not as good as it could be.
The object of the present invention is to further improve the air distribution unit.
The invention provides an air distribution unit comprising an external envelope, an air inlet duct for delivering air into the sound absorption chamber having an obliquely positioned sound absorption surface, and an air outlet chamber for receiving air from the sound absorption chamber and delivering air to an air outlet duct, wherein the sound absorption chamber through which the air flow tapers in cross-section and wherein the air changes its flow direction through at least 90° when flowing from one chamber into the other, characterised in that the air outlet chamber has an air discharge surface across which the air will flow and through which the air will flow towards a room space, the outlet chamber decreasing in cross-section in the direction of the air flow across the air discharge surface. In this manner the useless space of FI 73068 may be put to use.
As taught by the invention, the air distribution unit serves as an air terminal unit through which air can be made to flow into an interior space. The air distribution unit comprises a sound absorption surface positioned obliquely relative to the direction of the incoming air, which may be formed of sound absorption board material. Where the air flow enters the air outlet chamber, it changes direction by at least 90°, preferably substantially more than 90°, and at the maximum, 180°. The air flows into the rear part of the outlet chamber, which is located below the obliquely positioned sound absorption plate. In the air outlet duct a perforated plate or any equivalent air discharge surface may be used, whereby the supply of air into the interior space can be regulated as desired. The apparatus of the invention enables completely silent air supply to spaces where there are people.
The invention will be further described with reference to advantageous embodiments of the invention, as depicted in the figures of the accompanying drawings, but to which the invention is not intended to be exclusively confined.
Figure 1 is an axonometric perspective partially sectioned drawing of an air distribution unit according to the invention.
Figure 2 shows the air distribution unit of Figure 1, in cross-section along the line I-I in Figure 1.
The air distribution unit 10 comprises an outer envelope 11. The air enters a sound absorption chamber 13 through an air duct, as shown by arrow L₁. The underside of the sound absorption chamber 13 is confined by a planar, plate-like sound absorption plate 14 which comprises sound absorption material. The sound absorption plate 14 is positioned obliquely with respect to the air entry direction (direction of the x-axis). As shown by arrow L₂, the air flows through a space 13, which tapers in cross-section I-I, and discharges into an outlet chamber 15 through the gap between the oblique sound absorption plate 14 and a sound absorbing material layer 16 covering the inner surface of the outer envelope 11. The air changes direction (arrows L₃) on arriving in the outlet chamber 15, the change of direction being at least 90°, preferably substantially more than 90', and at the maximum, 180°.
The air discharges from the air outlet chamber 15 into an inner space or equivalent through an outlet duct 17. The outlet duct 17 comprises a perforated plate, louvre or other equivalent air discharge surface.
Positioning of the sound absorption plate obliquely so that the air has to change direction substantially through at least 90°, affords silent air discharge into the room space or equivalent. The air discharge into the room space is indicated by arrow L₄.
As indicated by arrow L₁ in Figure 2, the air flows parallel to the central axis x of the air inlet duct 12 into the sound absorption chamber 13, where it meets the sound absorption plate 14 positioned obliquely with respect to the air flow direction. The air continues as indicated by arrows L₂ in the sound absorption chamber 13 which tapers in cross-section I-I. The air flows from the sound absorption chamber 13 into the outlet chamber 15 through the gap between the end margin 14' of the sound absorption plate 14 and the sound absorption layer 16 on the outer envelope 11.
The air discharges from the part 15b of the outlet chamber below the sound absorption plate 14, through the outlet duct 17 into the interior space or equivalent. In the part 15a of the outlet chamber 15 where the air enters the outer chamber, the air flow direction changes through at least 90° with respect to the incoming air direction (arrow L₁, x-axis direction), preferably substantially more than 90°. The change of direction of the air flow is shown by arrows L₃. The air discharges from the rear part 15b of the outlet chamber into the interior space as shown by arrows L₄, flowing through the air outlet duct 17 and the air discharge surface 17'.
The air distribution unit 10 may also comprise a damper for regulating the air flow. This air flow regulating damper may be placed for example in the inlet duct 12. In alternative embodiments of the invention, the inlet duct 12 can be located in a wall of the sound absorption chamber 13 other than the end wall shown in Figures. Control of the air flow invariably produces noise, and the sound absorption chamber of the Figures efficiently damps the sound both from the regulator and from the duct system. In addition, the sound absorption chamber 13 smooths out the air flow entering the unit, which may be turbulent, and therefore the flow L₄ leaving the unit is controlled at all times. Consequently, the flow entering the sound absorption chamber 13 has no influence on the flow L₄.
As shown in Figure 2, a pressure pick-up or connector 18 is placed in the sound absorption chamber 13 communicating with a pressure measuring instrument. Pressure measurement further enables the air flow rate to be calculated. Pressure measurement is possible because of the efficient smoothing of the air flow in the sound absorption chamber. The inlet duct 12 may be located on any one of the walls of the sound absorption chamber, and the pressure in the sound absorption chamber 13 is reliably measurable independently thereof.
The air distribution unit of the invention may advantageously be used as an incoming air unit, or as a terminal member for incoming air. The apparatus may be mounted on the ceiling of a room, and the apparatus may be employed to distribute air without causing any significant draughts. On entering the part of the outlet chamber below the sound absorption plate, the air discharges through a perforated plate or other equivalent discharge surface into the interior space. Silent and draught free supply of fresh air to occupied spaces can be achieved using the means of the invention.

Claims

An air distribution unit (10) comprising an external envelope (11), an air inlet duct (12) for delivering air into a sound absorption chamber (13) having an obliquely positioned sound absorption surface (14), and an air outlet chamber (15) for receiving air from the sound absorption chamber (13) and delivering air to an air outlet duct (17), wherein the sound absorption chamber (13) through which the air flows tapers in cross-section (I-I) and wherein the air changes its flow direction through at least 90' when flowing from one chamber into the other, characterized in that the air outlet chamber (15) has an air discharge surface (17') across which the air will flow and through which the air will flow towards a room space, the outlet chamber (15) decreasing in cross-section in the direction of air flow across the air discharge surface (17').
The air distribution unit (10) according to Claim 1, wherein the sound absorption surface (14) comprises a sound absorption plate (14).
The air distribution unit of Claim 1 or 2, in which the sound absorption surface (14) is fitted between the sound absorption chamber (13) and air outlet chamber (15) to separate said chambers.
The air distribution unit (10) of Claim 3, in which the sound absorption plate is situated opposite the air discharge surface (17') of the air distribution unit (10).
The air distribution unit of any of the preceding Claims, wherein the air distribution unit (10) comprises a pressure pick-up within the sound absorption chamber (13) or a connector (18) communicating with a pressure measuring instrument, whereby the flow rate of the air flow passing through the unit may further be determined through pressure measurement.
The air distribution unit of any of the preceding Claims, wherein the change of the direction of the air flow is substantially over 90°.