WO1989007739A1

WO1989007739A1 - Air distribution unit

Info

Publication number: WO1989007739A1
Application number: PCT/FI1989/000021
Authority: WO
Inventors: Teuvo Pellinen
Original assignee: Halton Oy
Priority date: 1988-02-19
Filing date: 1989-02-13
Publication date: 1989-08-24
Also published as: DE68907148T2; DE68907148D1; FI880799A0; FI880799A; EP0354949B1; 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

Air distribution unit

The present invention concerns an air distribution unit comprising an outer envelope and an air inlet duct and an outlet duct, from the inlet duct the air being arranged to flow into a sound absorption chamber, said sound adsorption chamber comprising a sound absorption surface, advantageously an obliquely positioned sound absorption plate.

Through the earlier patent application No. 850982 by the same applicant is known a terminal device for incoming air comprising an air inlet duct and an air outlet duct. In the apparatus design of prior art, the air is arranged to meet an oblique air absorption surface in the inlet air means. In the area behind the oblique air absorption surface remains a useless space in the apparatus design of prior art. The sound absorption capacity of the apparatus design of prior art is not as good as it could be.

The object of the invention is to further improve the above apparatus design. An improved apparatus design has in fact been achieved with a sound absorption unit, which is characterized in that the air distribution unit contains an obliquely positioned sound bsorption surface, advantageously a sound absorption plate, such that the air after entering the sound absorption chamber flows in a sound absorption chamber space tapering in cross-section, and flows from the air sound absorption chamber into the air outlet chamber of the air distribution unit and hereat changes flow direction at least 90°, substantially more than 90°. In this manner the useless space known in the earlier application has been put to use.

As taught by the invention, an air distribution unit has been implemented which 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 and which has been formed of sound absorption board material. When the air enters the sound absorption chamber of the air distribution unit, it flows in the sound absorption chamber in a space of the sound absorption chamber tapering in cross-section. From the sound absorption chamber the air flows into the air outlet chamber of the air distribution unit. In the part of the air outlet chamber which is foremost in relation to the incoming flow direction the air flow changes direction at least 90°, and 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 may be used, or another equivalent air discharge surface, whereby the supply of air into the interior space can be regulated as desired. The apparatus design of the invention enables completely silent air supply to spaces where people are staying.

The invention is described in the following, referring to certain advantageous embodiments of the invention, depicted in the figures of the drawings attached, but to which the invention is not intended to be exclusively confined.

In Fig. 1 is depicted in axonometric perspective, and partly cut- open, an air distribution unit according to the invention.

Fig. 2 presents an air distribution unit according to the invention in cross-section, along the line I-I in Fig. 1.

The air distribution unit 10 of the invention comprises an outer envelope 11. The air is arranged to enter the air absorption chamber 13 through the air duct, as shown by arrow L₁. The sound absorption chamber 13 is on its underside confined by an air absorption plate 14, which is a planar, plate-like part comprising sound absorption material. The sound absorption plate is disposed obliquely against the air entry direction (direction of the x-axis). The air flows, as shown by arrow L₂ in a space of the sound absorption chamber 13 tapering relative to the cross-section I-I and discharges into the outlet chamber 15 through the gap between the oblique sound absorption plate 14 and the sound absorbing material course 16 covering the inner surface of the outer envelope 11. The air changes direction (arrows L₃) on arriving in the outlet chamber 15, and the change of direction is at least 90°, and in its substantial part more than 90°, and at the maximum, 180°.

From the air outlet chamber 15 the air discharges through the outlet duct 17 into an interior space or equivalent. The outlet duct 17 comprises a perforated plate, a louvre or another equivalent air discharge surface.

The oblique positioning of the sound absorption plate as taught by the invention specifically in such manner that the air has to change direction substantially 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

In Fig. 2 is presented in cross-section the air distribution unit of Fig. 1. The air flows as indicated by arrow L₁ 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 against the air flow direction. The air continues as indicated by arrows L₂ in the sound absorption chamber 13 tapering relative to the cross -section I-I. From the sound absorption chamber 13 the air flows into the outlet chamber 15 through the gap between the end margin 14' of the sound absorption plate 14 and the sound absorption course 16 abutting on the outer envelope 11.

From the outlet chamber 15, from the part 15b below the sound absorption plate 14, the air discharges through the outlet duct 17 into the interior space or equivalent. In the part 15a of the outlet chamber 15 which is foremost relative to the. incoming air direction, the air flow direction changes at least 90° with reference to the incoming air direction (arrow L₁ ; x-axis direction), substantially more than 90°. Arrows L₃ illustrate the air flow which has changed direction. The air discharges from the rear part 15b of the outlet chamber into the interior space as shown by arrows L₄, through the air outlet duct 17 and the air discharge surface 17'.

The air distribution unit 10 may also comprise a damper regulating the air flow. Said air flow -regulating damper may be placed e.g. in the inlet duct 12. Such embodiments of the invention can furthermore be contemplated in which the inlet duct 12 is located in a wall of the sound absorption chamber 13 other than the the end wall shown in the figure. When the air flow is being controlled, noise is invariably produced, and the sound absorption chamber of the present invention efficiently damps the sound both from the regulator and from the duct system. In addition, the sound absorption chamber 13 smooths out the flow entering the means, which may be turbulent indeed, and therefore, the flow L₄ exiting from the means is controlled at all times. Consequently, the flow entering the sound absorption chamber 13 exerts no influence on the flow L₄.

As shown in Fig. 2, in the sound absorption chamber 13 has been placed a pressure pick-up or a connector 18 communicating with a pressure measuring instrument. Pressure measruement further enables the air flow rate to be calculated. Pressure meauserment is specifically rendered possible by the efficient action of the sound absorption chamber as a space smoothing out the air flow. The inlet ducts 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 independent thereof.

The air distribution unit of the invention may advantageously serve as incoming air unit, or as incoming air terminal member. The apparatus may be mounted on the ceiling of a room space, and the apparatus may be employed to distribute the air without causing any significant sensational draught. On entering the part of the outlet chamber below the sound absorption plate, the air discharges through a perforated plate or another equivalent discharge surface into the interior space. Silent, and draughtfree, supply of fresh air to spaces occupied by persons can be implemented using the means of the invention.

Claims

1. An air distribution unit (10), comprising an external envelope (11) and an air inlet duct (12), and an oulet duct (17); from the inlet duct, the air is being arranged 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) characterized in that the air, after entering the sound absorption chamber (13), flows in a space of the sound absorption chamber (13) tapering in its cross-section (I-I), and flows from the sound absorption chamber (13)n into the air outlet chamber (15) of the air distribution unit (10), and hereby changes its flow direction for at least 90°, substantially over 90°.

2. Air distribution unit according to claim 1, characterized in that the means comprises a design part separating the sound absorption chamber (13) and the outlet chamber (15) produced from a sound absorption plate (14), whereby the air is disposed to discharge in an interior space or equivalent substantially from a space (15b) of the outlet chamber (15) below the sound absorption space (14).

3. Air distribution unit according to claim 1 or 2, characterized in that the air distribution unit comprises a pressure pick-up within the sound absorption chamber (13) or a connector (18) communicating with a pressure measuring instrument, whereby through pressure measurement may further be determined the flow rate of the air flow passing through the means.