GB2304888A

GB2304888A - Air treatment apparatus

Info

Publication number: GB2304888A
Application number: GB9617713A
Authority: GB
Inventors: David Peter Bloomer
Original assignee: Smiths Group PLC
Current assignee: Smiths Group PLC
Priority date: 1995-09-02
Filing date: 1996-08-22
Publication date: 1997-03-26
Anticipated expiration: 2016-08-22
Also published as: GB9617713D0; GB2304888B

Abstract

A ceiling mounted air treatment unit has a porous lower wall 11 providing an inlet through which air is drawn into the apparatus. Four peripheral side walls 12 to 15 each have two pairs of directable louvers 40 through which treated air is expelled. The louvers 40 are set so that the expelled air emerges at an angle below the horizontal and at an angle to one side of the normal to the peripheral wall so that the emerging air forms a swirling path around the unit helping to entrain air up into the inlet. The unit may have four compartments 21 to 24 inside, each with its own fan 51 to 54, and each opening through a pair of louvres 40 on adjacent walls. The unit may be ceiling mounted and incorporate a filter 31.

Description

AIR TREATMENT APPARATUS This invention relates to air treatment apparatus.

Air treatment apparatus are known in which air is drawn into the apparatus, is treated in some way and is then expelled. The treatment may include filtering, deodorising, warming, cooling, humidification, ionizing or being given a fragrance. The efficiency of the apparatus depends on various factors such as the power of the air mover within the apparatus, the location of the apparatus and the air flow paths into and out of the apparatus.

It is an object of the present invention to provide improved air treatment apparatus.

According to the present invention there is provided air treatment apparatus having a housing with an upper wall, a lower wall spaced below the upper wall and a peripheral side wall extending around the housing between the upper and lower walls, the upper wall being adapted to be mounted to a room ceiling surface, the lower wall being arranged horizontal and being porous to air entering the apparatus, the peripheral side wall having a plurality of air directors located around the entire periphery of the housing, the apparatus including air moving means for drawing air in through the lower wall and for forcing it out through the air directors, and air treatment means for treating air during its passage through the apparatus, and the air directors being arranged to direct air emerging out of the apparatus at an angle below the horizontal and at an angle to one side of a normal from the surface of the peripheral wall such that the emerging air forms a swirling path around the apparatus to help entrain air up into the lower wall of the housing.

The air directors may be adjustable louvers and they may be closable. The apparatus preferably has four peripheral side walls and four compartments each being bounded by two of the side walls and opening through air directors on adjacent ones of the side walls, the apparatus having four air moving means, one in each compartment. Each compartment preferably opens through a pair of air directors on adjacent walls. The four compartments may be separated from one another by internal walls, the internal walls having small channels formed therein to enable air flow between the compartments. The air moving means preferably includes a fan and the air treatment means may include a filter.

An air filtration unit according to the present invention, will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of the underside of the unit; Figure 2 is a cross sectional elevation of the unit; Figure 3 is an exploded, perspective view of the underside of the unit; Figure 4 is a view of a part of one of the louver assemblies; and Figures 5 and 6 are schematic plan views illustrating air flow from the unit with different settings of the louvers.

With reference first to Figures 1 to 3, the air filtration unit has an outer housing 1 of square shape with an upper wall 10, a lower wall 11 and four side walls 12 to 15. The housing is mounted on the ceiling 16 of a room, with the upper and lower walls horizontal and the side walls vertical.

The housing 1 is divided internally into four compartments 21 to 24 by two intersecting walls 25 and 26 extending orthogonally, parallel to the side walls 12 to 15 midway across their width. Small channels (not shown) are formed in the walls 25 and 26 to enable air to flow between the compartments 21 to 24.

The lower wall 11 comprises an upper plate 28, having four circular openings 29 arranged centrally of the compartments 21 to 24, and a lower grille plate 30 formed of a mesh or similar porous structure. A filter assembly 31 is sandwiched between the upper plate 28 and the lower plate 30; the filter assembly 31 comprises layers of a reticulated foam material, a pleated pre-charged material and a layer of activated carbon granules, the layers being supported by an outer cardboard frame and arranged with the carbon layer uppermost.

With reference now also to Figure 4, each of the side walls 12 to 15 has four air directors in the form of louver assemblies 40. The four louver assemblies 40 along each wall are arranged in two pairs of closely-spaced assemblies, each pair opening into respective ones of the compartments 21 to 24. Each louver assembly 40 has several vertically-oriented flaps 41 within a frame 42 (only one of which is shown in Figure 4). The flaps 41 can be angularly displaced about a vertical axis, whereas each frame 42 itself can be angled up or down. The louver assemblies 40 can also be closed or partially closed by a shutter (not shown).

The upper wall 10 of the housing 1 is secured and sealed to the side walls 12 to 15 and has several fixing apertures by which screws, bolts or other fixing means secure the filtration unit to the ceiling 16.

The filtration unit has four centrifugal fan units 51 to 54, one in each compartment 21 to 24 above the openings 29 in the plate 28. Each fan unit 51 to 54 has an electric motor arranged for rotation about a vertical axis so that air admitted through the lower wall 11 is driven outwardly through the louver assemblies 40 in the side walls 12 to 15. The motors of each fan unit 51 to 54 are electrically supplied by a control unit 60 in the housing 1, which is, in turn, connected to an electrical supply cable extending through an opening in the upper wall 10 and the ceiling 16. The control unit 60 has an infra-red responsive photodiode 61 mounted on the lower wall 11, the control unit being controlled by operation of a remote infra-red control unit 62.

When the filtration unit is installed on the ceiling 16, the louver assemblies 40 are adjusted so that air flows out at the same angle of about 45O to the normal to the side walls 12 to 15 (as shown in Figure 5) and downwardly at an angle of about 30O to the horizontal, these angles being varied according to the size of the room and the location of the filtration unit.

The louver assemblies 40 are set so that the air flows around the filtration unit in the same sense, to create a swirling, downwardly directed flow of air. This pattern of airflow has been found to be particularly effective in entraining air from a wide range into the inlet of the unit provided through the lower wall 11. Air is sucked through the filter sheet 31, which removes smoke and odours, and is then blown outwardly through the louver assemblies 40.

Where the filtration unit can only be mounted close to a wall of the room, louvers along the side wall of the unit adjacent to the wall of the room can be closed so that no air emerges from that side wall. Because each compartment 21 to 24 has louvers on two side walls, closing the louvers along one wall will not prevent air flow from the two fans opening from that wall, but will instead increase the flow out of the other louvers opening from the compartments. If all four louvers are closed, air can flow through the channels in the walls 25 and 26 into the adjacent compartments Instead of angling the louver assemblies so that air flows out of each at the same angle, the leeward louvers of each pair may be angled at a smaller angle to the normal than are the louvers on the upstream side, so that air from the leeward louvers is entrained by air from the adjacent louver, as shown in Figure 6. By appropriately angling the louvers, air from one pair of louvers can impinge on air from the leeward louvers on the same wall.

The invention can be used in other air treatment apparatus, such as heating and air conditioning apparatus, deodorisers, air ionizers and the like.

Claims

1.Air treatment apparatus having a housing with an upper wall, a lower wall spaced below the upper wall and a peripheral side wall extending around the housing between the upper and lower walls, wherein the upper wall is adapted to be mounted to a room ceiling surface, the lower wall being arranged horizontal and being porous to air entering the apparatus, wherein the peripheral side wall has a plurality of air directors located around the entire periphery of the housing, wherein the apparatus includes air moving means for drawing air in through the lower wall and for forcing it out through the air directors, and air treatment means for treating air during its passage through the apparatus, and wherein the air directors are arranged to direct air emerging out of the apparatus at an angle below the horizontal and at an angle to one side of a normal from the surface of the peripheral wall such that the emerging air forms a swirling path around the apparatus to help entrain air up into the lower wall of the housing.

2. Apparatus according to Claim 1, wherein the air directors are adjustable louvers.

3. Apparatus according to Claim 1 or 2, wherein the air directors are closable.

4. Apparatus according to any one of the preceding claims, wherein the apparatus has four peripheral side walls and four compartments each being bounded by two of said side walls and opening through air directors on adjacent ones of said side walls, and wherein the apparatus has four air moving means, one in each compartment.

5. Apparatus according to Claim 4, wherein the apparatus has two pairs of air directors on each side wall, and wherein each compartment opens through a pair of air directors on adjacent walls.

6. Apparatus according to Claim 4 or 5, wherein the four compartments are separated from one another by internal walls, and wherein the internal walls have small channels formed therein to enable air flow between the compartments.

7. Apparatus according to any one of the preceding claims, wherein the air moving means includes a fan.

8. Apparatus according to any one of the preceding claims, wherein the air treatment means includes a filter.

9. Apparatus substantially as hereinbefore described with reference to the accompanying drawings.

10. Any novel feature or combination of features as hereinbefore described.