GB2215452A

GB2215452A - A fan assembly

Info

Publication number: GB2215452A
Application number: GB8806499A
Authority: GB
Inventors: Man Kwan Wong
Original assignee: CARROWAY ENTERPRISES Ltd
Current assignee: CARROWAY ENTERPRISES Ltd
Priority date: 1988-03-18
Filing date: 1988-03-18
Publication date: 1989-09-20
Also published as: GB8806499D0

Abstract

A fan assembly is provided operable both to circulate air and to clean and filter air. The assembly includes an air cleaner part (1) and an air circulation pan (2). The air cleaner part (1) has a casing (3) with air inlet apertures (4) at the bottom end and air outlet apertures (5) at the top end. Replaceable filter assemblies (6) are removeably located in the apertures (4). A first rotatable fan means (8) housed in the casing (3) is operable to draw air through the filter assemblies (6) apertures (4) and expel the filtered air from the casing (3) via the apertures (5). The air circulation part (2) includes a second rotatable fan means (10) mounted externally of the casing (3) and rotatably one or the other direction to circulate air externally of the casing (3). The first and second fan means (8, 10) are rotatable together or separately as desired. <IMAGE>

Description

A FAN ASSEMBLY This invention relates to a fan assembly for use in a substantially enclosed space such as a room in a building.

Many different fan assemblies are known for use in circulating air in a room and such known fan assemblies can either be ceiling mounted or free standing. However they are mounted or located these known fan assemblies frequently both disturb and circulate dust with consequent increase in dust level in the atmosphere in a room. This in turn leads to increased work for the occupant of the room in dusting furniture therein and in some circumstances can lead to a greater chance of the occupants of thc room suffering from asma attacks if they are sensitive to household dust.

There is thus a need for a generally improved fan assembly with reduced or minimized dust circulation.

According to the present invention there is provided a fan assembly for use in a substantially enclosed space, having an air cleaner part and an air circulation part, wherein the air cleaner part includes a casing having air inlet means at one end thereof and air outlet means at another end thereof, replaceable filter means associated with said air inlet means, and a first rotatable fan means housed in the casing and operable selectively to draw air into the casing from the surrounding enclosed space through the air inlet means and associated filter means for air cleaning purposes and to expel the filtered cleaned air out of the casing back into the enclosed space, through the air outlet means, and wherein the air circulation part includes a second rotatable fan means mounted externally of the casing and rotatable in one or the other direction to circulate air externally of the casing in the enclosed space, the first and second fan means being rotatable together or separately as desired.

Such a fan assembly may be ceiling or wall mounted. Operation of the air cleaner part enables the air being circulated to be filtered of dust or other particles and thereby cleaned before being passed back into circulation in the enclosed space. This considerable reduces the amount of dust being circulated with consequent beneficial results for the occupants of the room in reduced dusting and reduced liklihood of asma attacks.

Preferably the casing is drum-like in shape having the air inlet means at one end thereof and the air outlet means at the opposite end thereof.

Conveniently the air inlet means is three sector shaped apertures provided in and through said one end of the casing opposite to said another end of the casing and the removable filter means is in the form of three sector shaped sheet filter assemblies removably locatable one in each said air inlet means apertures. In this way the filters may be removed and replaced at intervals determined by the amount of dust in the atmosphere so as to maintain the efficiency of the air cleaner part.

For a better understanding of the present invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a side view of a fan assembly according to one embodiment of the invention for ceiling mounting, Figure 2 is a plan view from above of the assembly of Figure 1 to a reduced scale, Figure 3 is a plan view from below of the assembly of Figure 1 to a reduced scale, Figure 4 is a vertical cross-sectional view through part of the assembly of Figures 1 to 3, on an enlarged scale, and Figure 5 is a horizontal cross-sectional view taken on the line A-A in Figure 4, to an enlarged scale.

A fan assembly according to one embodiment of the invention is shown in Figures 1 to 5 of the accompanying drawings in the form of a ceiling mounted assembly. It is to be understood, however, that although the invention will be described and illustrated in terms of a ceiling mounted fan assembly, a fan assembly of the invention could alternatively be wall mounted.

As shown in Figures 1 to 5 of the accompanying drawings a fan assembly the invention for use in a substantially enclosed space includes an air cleaner part generally referenced 1 and an air circulation part generally referenced 2.

The air cleaner part 1 includes a casing 3 made of any convenient material such as metal. Air inlet means in the form of three sector shaped apertures 4 are provided in and through one end of the casing 3. In this instance where the fan assembly is a ceiling mounted fan assembly the air inlet means are provided in the bottom end of the casing 3 as illustrated. The air cleaner part 1 also includes air outlet means in the form of a ring of spaced apart apertures 5 provided around and through the end of the casing 3 opposite to the end provided with the apertures 4. In this embodiment the casing 3 is drum-like in shape and the apertures are provided respectively in opposite ends of the drum-like shape.

Replaceable filter means in the form of three sector shaped sheet filter assemblies 6 are provided in the air cleaner part 1 for removeable location one in each of the air inlet means apertures 4. As can be seen particularly from Figures 3 and 4 of the drawings each filter assembly 6 is basically in the form of two perforated frames between which one or more layers of filter material are sandwiched. The frames and filter material forming the filter assembly 6 conveniently are removably attached to the casing 3 by means of one or more screw threaded bolts 7, preferably two for each assembly as illustrated, which can be tightened or loosened manually by a user of the fan assembly to remove or replace the filter assembly 6.

Conventionally obtainable filter material can be used to give the replaceable filter assemblies 6 a useful life of up to 1500 hours. Thus when the filter material of the filter assemblies 6 becomes clogged with dust and other waste material extracted from the surrounding air the assemblies can be replaced.

Also included in the air cleaner part 1 is a first rotatable fan means generally indicated at 8, housed in the casing 3 as shown particularly in Figure 4. This fan means 8 is operable selectively to draw air into the casing 3 from the surrounding enclosed space through the air inlet means apertures 4 and associated filter assemblies 6 for air cleaning purposes and to expel the filtered cleaned air out of the casing 3 back into the enclosed space through the air outlet means apertures 5. A fixed filter means in the form of a sheet of filter material 9 extends across the casing interior between the air outlet means apertures 5 and the first rotatable fan means 8 as can be seen from Figure 4.This additional filter 9 has the effect partially of preventing dust from falling into the casing 3 through the apertures 5 and also acts as an additional filter for air drawn through the casing 3 by the fan means 8 which has already been filtered by the filter assembly 6. Thus the filter 9 does not receive much dust and does not require to be replaceable although it can be replaced, if necessary, by disassembly of the casing 3.

The air circulation part 2 includes a second rotatable fan means generally indicated at 10. The fan means 10 is mounted externally of the casing 3 and is rotatable in one or other direction to circulate air externally of the casing 3 in the enclosed space. The first fan means 8 and second fan means 10 can be rotated together or separately as desired and the direction of rotation of the second rotatable fan means 10 at least can be reversed.

As can be seen particularly from Figure 4 of the drawings the assembly of the invention includes a non-rotatable spindle 11 passing centrally through the casing 3 from the air inlet means end to the air outlet means end of the casing. This spindle 11 is hollow for reasons which will be hereinafter described. The first rotatable fan means 8 includes a first electric motor 12 mounted on the spindle 11 for rotation therearound in the casing 3 and a plurality of fan blades 13, conveniently four or five thereof, carried by and extending radially from the first motor 12 exterior in the casing 3. The electric motor 12 may be of any convenient type such as a six-pole, outer rotor capacitor induction motor of a fortyfive watt rating.

The fan blades 13 can be made from any convenient materials such as plastics.

The second rotatable fan means 10 includes a second electric motor 14 mounted on the spindle 11 for rotation therearound externally of the casing 3 at the air outlet means end of the casing, and a plurality of fan blades 15 carried by an extending radially from the motor 14 exterior radially beyond the outer periphery of the casing 3 as can be seen particularly in Figures 1 to 3. The motor 14 can be of any desired conventional form and preferably is an 18 pole outer rotor capacitor induction motor of a seventy watt rating. In the illustrated embodiment the fan blades 15 are four in number made from wood such as oak, with decorative cane inserts 16 on one side thereof.

As the foresaid the spindle 11 is hollow and the assembly includes control and switch means 17 for the two electric motors 12 and 14. The control and switch means 17 is located at the bottom end of the hollow spindle 11 at the air inlet means end of the casing 3. Electric supply current cables 18 pass to the control and switch means 17 and to the two motors 12, 14 through the hollow spindle 11 as shown in Figure. 4. Switch means such as pull switches 19 are provided for switching the two fan motors 12 and 14 on and off independently of each other, for reversing the direction of movement of the fan blades 15 and for varying the speed of rotation of the motor 12 and attached fan blades 13.

The spindle 11 is provided at its end remote from the control and switch means 17, above the second electric motor 14, with ceiling attachment means 20 for hanging the assembly vertically from a ceiling so that the air inlet means is at the bottom of the casing 3 and the air outlet means is at the top of the casing 3. In this position the fan blades 15 are located above the casing 3 and are thus furthest away from a potential user of the fan assembly so that the user cannot come into contact with the fan blades 15 whilst changing the replaceable filter assemblies 6 at the bottom of the casing 3.

Thus in operation air may be drawn through the casing 3 via the filter assemblies 6, air inlet apertures 4 filter 9 and air outlet apertures 5 to filter and remove dust and other particles from the air. The speed at which the air is drawn through the casing 3 maybe varied by varying the speed of rotation of the motor 12 and attached fan blades 13. At the same time or separately from this filtering effect the remaining air in the substantially enclosed space in which the fan assembly of the invention is hanging can be circulated by means of the fan blades 15. These fan blades 15 can be caused to rotate in one or the opposite direction by appropriately controlling the motor 14 | via the control and switch means 17 to displace the air upwardly of the assembly or downwardly of tSe assembly as desired.

Claims

1. A fan assembly for use in a substantially enclosed space, having an air cleaner part and an air circulation part, wherein the air cleaner part includes a casing having air inlet means at one end thereof and air outlet means at another end thereof, replaceable filter means associated with said air inlet means, and a first rotatable fan means housed in the casing and operable selectively to draw air into the casing from the surrounding enclosed space through the air inlet means and associated filter means for air cleaning purposes and to expel the filtered cleaned air out of the casing back into the enclosed space, through the air outlet means, and wherein the air circulation part includes a second rotatable fan means mounted externally of the casing and rotatable in one or the other direction to circulate air externally of the casing in the enclosed space, the first and second fan means being rotatable together or separately as desired.

2. A fan assembly according to claim 1, wherein the casing is drum-like in shape having the air inlet means at one end thereof and the air outlet means at the opposite end thereof.

3. A fan assembly according to claim 2, wherein the air outlet means is a ring of spaced apart apertures provided around and through said another end of the drum shaped casing, and including fixed air filter means in the form of a sheet of filter material extending across the casing interior between the air outlet means apertures and the first rotatable fan means.

4. A fan assembly according to claim 3, wherein the air inlet means is three sector shaped apertures provided in and through said one end of the casing opposite to said another end of the casing and wherein the replaceable filter means is in the form of three sector shaped sheet filter assemblies removably locatable one in each said air inlet means apertures.

5. A fan assembly according to claim 4, including a non rotatable spindle passing centrally through the casing from the air inlet means end to the air outlet means end.

6. A fan assembly according to claim 5, wherein the first rotatable fan means includes a first electric motor mounted on the spindle for rotation therearound in the casing and a plurality of fan blades carried by and extending radially from said first motor exterior in the casing.

7. A fan assembly according to claim 5 or claim 6, where in the second rotatable fan means includes a second electric motor mounted on the spindle for rotation therearound externally of the casing at the air outlet means end thereof, and a plurality of fan blades carried by a extending radially from said second motor exterior radially beyond the outer periphery of the casing.

8. A fan assembly according to claim 7, wherein the spindle is hollow and including control and switch means for the two electric motors, located at the air inlet means end of the casing, electric supply current cables, to the control and switch means and to the two electric motors5 passing through the hollow spindle.

9. A fan assembly according to claim 8, wherein the spindle is provided at its end remote from the control and switch means, above the second electric motor, with ceiling attachment means for hanging the assembly vertically from a ceiling so that the air inlet means is at the bottom of the casing, the air outlet means is at the top of the casing and the second rotatable fan means is located above the casing at the air oulet means end thereof.

10. A fan assembly for use in a substantially enclosed space, substantially as hereinbefore described and as illustrated in the accompanying drawings.