FAN

Abstract

According to an aspect, there is provided a fan including: a housing defining an opening which extends through the housing; a first air flow channel defined within the housing, having a first air inlet, a first air outlet and a first impeller for driving air from the first inlet to the first outlet; and a second air flow channel defined within the housing, including a second air inlet, a second air outlet and a second impeller for driving air from the second inlet to the second outlet, wherein the first and second air outlets draw air through the opening.

Description

FIELD OF THE INVENTION

The present disclosure relates to a fan for providing air flow having no external blades.

BACKGROUND OF THE INVENTION

Typical fans comprise a set of blades which are arranged to rotate about a central axis, which are driven by a motor to provide an air flow, typically a cooling air flow.

Air multipliers, or bladeless fans, are a type of fan which don't include a set of external blades. In typical air multipliers or bladeless fans, an air flow is provided by an impeller which is located within a base of the fan, which drives air from an inlet to an outlet. The fan has an opening at the centre of the fan, through which air emitted from the outlet is drawn by the Coanda effect, resulting in an increase in air flow. As the impeller rotates at high speeds, the flow of air is smoother than that of a regular bladed fan, and as a result the air flow feels more natural. Further, there are safety advantages associated with the lack of external blades.

However, airflow is constrained by the limitations of the impeller, particularly when an air filter is used to purify air. It is therefore desirable to provide an improved fan.

SUMMARY OF THE INVENTION

According to an aspect, there is provided a fan comprising: a housing defining an opening which extends through the housing; a first air flow channel defined within the housing, comprising a first air inlet, a first air outlet and a first impeller for driving air from the first inlet to the first outlet; and a second air flow channel defined within the housing, comprising a second air inlet, a second air outlet and a second impeller for driving air from the second inlet to the second outlet, wherein the first and second air outlets are configured to draw air through the opening.

The opening may extend completely through the housing. The opening may extend completely through the housing in a depth direction. The opening may extend through the housing from a first side to a second side of the housing. The opening may be an airflow opening. The opening may be configured such that, in use of the fan, air flows through the opening. The opening may be substantially cylindrical. The airflow opening may be defined by a radially inner surface of the housing. The housing may have an inner surface defining the opening and an outer external surface. The housing may have a radially inner surface defining the opening and a radially outer external surface.

The first and second air outlets may be configured to draw air through the opening when air is emitted from the first and second air outlets. The first and second air outlets may be configured to draw air through the opening and from around an outer surface of the housing. The first and second air outlets may be configured to draw air through the opening and from around an outer surface of the housing when air is emitted from the first and second air outlets. The first and second outlets may be configured to discharge air into the vicinity of the opening. The first and second outlets may be configured to discharge air into the opening. The first and second air outlets may be located on an inner surface of the housing. The first and second air outlets may be located on a radially inner surface of the housing,

The first and second outlets may be configured to draw air through the opening by the Coanda effect. The first and second outlets may be configured to draw air from around an outer surface of the housing by the Coanda effect. Air emitted by the first and second opening may entrain the surrounding air. The volume of air driven, or discharged, by the fan may therefore be greater than that taken in at the air inlets and emitted at the air outlets of the fan. The shape of the first and second air outlets may be configured to provide the Coanda effect.

The fan may also be known as an air mover. The fan may be a bladeless fan or air multiplier. The fan may be an air purifier. The fan may be a humidifier, and/or a heater. The impeller may comprise a rotor and blades or vanes for transmitting motion. The impeller may transmit motion to the air in the air flow channel.

In use, air may be drawn into the first and second inlets from the back of the housing. The air may flow along the first and second air channels and be emitted from the housing at the first and second outlets. The first air channel may comprise the first inlet, a first inlet chamber, the first impeller, a first outlet chamber, and the first outlet. The second air channel may comprise the second inlet, a second inlet chamber, the second impeller, a second outlet chamber, and the second outlet.

By providing two air flow channels, each comprising an inlet, impeller and outlet, the volume of air drawn into the fan may be increased, such that an efficient air flow may be provided. The fan cooling performance may therefore be improved. The air flow channels may be independent of each other. The air flow channels may be separate from each other. The fan may comprise two or more air flow channels. Each air flow channel may comprise at least one air inlet, at least one air outlet and at least one impeller for driving air between the inlet(s) and outlet(s). The housing may enclose each air flow channel.

The housing may define a centreline, and wherein the first impeller is on one side of the centreline and the second impeller is on the other side of the centreline. The first and second impellers may be located in the housing at opposite sides of the opening. The centreline may be a centreplane. The centreplane may define an axis of symmetry of the housing. By locating the first and second impeller on different sides of the centreline or centreplane, a compact arrangement of the impellers, and therefore the fan may be provided.

The first and second impellers may have a rotation axis, and the first and second impellers may be arranged such that the rotation axes are parallel with the centreline. The first and second impellers may be arranged such that the rotation axes are parallel with a centreplane.

The housing may be elongate. The first impeller may be located towards or adjacent to a first end of the housing, and the second impeller may be located towards or adjacent to a second end of the housing, opposite the first end. An elongate housing has a length longer than its width. The fan may be positionable in a vertical orientation such that the longest dimension is arranged vertically. The fan may be positionable in a horizontal orientation such that the longest dimension is arranged horizontally. The opening may be substantially cylindrical through the housing.

The housing may be substantially cylindrical, the diameter of the cylinder defining a width and depth of the housing.

The first and second inlets may be located on an inner surface of the housing. The first and second inlets may be located on a radially inner surface of the housing. The first and second inlets may be located in the opening. Placing the inlets on the inner surface of the housing may enable the fan to be placed in a range of positions and orientations whilst allowing an acceptable air flow through the inlets. Placing the inlets on the inner surface of the housing may enable the fan to be placed in a range of positions and orientations without blocking air flow to the inlets. The arrangement of the inlets on the inner surface of the housing may provide a fan having a compact size. The position of the air inlets on the inner surface of the housing may allow air to be drawn through the opening when the impeller is used to drive air from the inlet to the outlet.

The first and second inlets may be located at opposite sides of the opening. The first and second inlets may be located at radially opposite sides of the opening. The first and second inlets may be located at opposite sides of the opening in a width direction of the housing. The first and second inlets may be located at opposite sides of the opening in a length direction of the housing. The first and second inlets may be located, such that, when the fan is positioned in a vertical position, the inlets are positioned at horizontally opposite sides of the opening, such as the first inlet being located at a left hand side of the opening and the second inlet being located at a right hand side of the opening. The first and second inlets may be located, such that, when the fan is positioned in a vertical position, the inlets are positioned at vertically opposite sides of the opening, such as the first inlet being located at a top side of the opening and the second inlet being located at a bottom side of the opening. The fan may be positionable at a range of positions and orientations, and the relative arrangement of the first and second inlets will depend upon the orientation of the fan.

At least one motor may be provided in the fan. A single motor may drive the first and second impellers. Each impeller may have an individual motor arranged to drive the impeller. The or each motor may be provided in the housing.

The first and second impellers may be located in the housing. The first and second impellers may be located in the housing at opposite sides of the opening. By locating the first and second impellers at opposite sides of the opening, the fan may be more compact in size. The first and second impellers may be located at opposite sides of the opening in a length direction of the housing. The first and second impellers may be located at opposite sides of the opening in a width direction of the housing. The first and second impellers may be located at radially opposite sides of the opening. The first and second impellers may be located at opposite sides of the opening in a length direction of the housing. The first and second impellers may be located at opposite sides of the opening in a width direction of the housing. The first and second impellers may be located, such that when the fan is positioned in a vertical position, the impellers are positioned at vertically opposite sides of the opening, such as the first impeller being located at a top side of the opening and the second impeller being located at a bottom side of the opening. The first and second impellers may be located, such that, when the fan is positioned in a vertical position, the impellers are positioned at horizontally opposite sides of the opening, such as the first impeller being located at a left hand side of the opening and the second impeller being located at a right hand side of the opening. The fan may be positionable at a range of positions and orientations, and the relative arrangement of the first and second impellers will depend upon the orientation of the fan. The impellers may be high speed impellers. The impellers may be mixed flow impellers.

At least one of the first and second air flow channels may comprise a filter. By placing a filter in at least one of the first and second air flow channels, the fan may be an air purifier. The filter is configured to clean the air passing through the air flow channel, such that cleaner air is emitted from the outlet. The filter removes impurities from the air. Adding a filter to an air flow channel adds resistance to the air flow through the air flow channel. By providing two air inlets, two impellers, and two independent air flow channels the effect of the added resistance is reduced to provide an improved purification performance. The filter may be located between the air inlet and the impeller. The filter may be located in the housing behind the air inlet. The filter may be located in the housing adjacent the air inlet.

At least one of the first and second air flow channels may comprise a heating element and/or a humidifier. The first and second air flow channels may each comprise a heating element and/or a humidifier. At least one of the first and second air flow channels may comprise a cooling element and/or a dehumidifier. The first and second air flow channels may each comprise a cooling element and/or a dehumidifier.

The first and second outlets may each comprise a curved guiding surface. The curved guiding surface guides air so as to entrain the surrounding air by the Coanda effect.

The first and second outlets may each comprise a slit shaped outlet. The first and second outlets may be formed on the circumference of the opening. The slit shaped outlet guides air so as to entrain the surrounding air by the Coanda effect.

The first and second air outlets may be located at opposite sides of the opening. The first and second outlets may be located at radially opposite sides of the opening. The first and second outlets may be located at opposite sides of the opening in a width direction of the housing. The first and second outlets may be located at opposite sides of the opening in a length direction of the housing. The first and second outlets may be located, such that, when the fan is positioned in a vertical position, the outlets are positioned at horizontally opposite sides of the opening, such as the first outlet being located at a left hand side of the opening and the second outlet being located at a right hand side of the opening. The first and second outlets may be located, such that when the fan is positioned in a vertical position, the outlets are positioned at vertically opposite sides of the opening, such as the first outlet being located at a top side of the opening and the second outlet being located at a bottom side of the opening. The fan may be positionable at a range of positions and orientations, and the relative arrangement of the first and second outlets will depend upon the orientation of the fan.

In use, air may flow through the opening from a back to a front of the housing. The first and second air outlets may be located towards the front of the housing. The first and second air inlets may be located towards the back of the housing. The first and second air inlets may be located substantially behind the first and second air outlets. By locating the air inlets towards the back of the housing, behind the air outlets, the inlets may draw air from the back of the fan. The opening may be wider at the back of the housing than the front of the housing.

To avoid unnecessary duplication of effort and repetition of text in the specification, certain features are described in relation to only one or several aspects or embodiments of the invention. However, it is to be understood that, where it is technically possible, features described in relation to any aspect or embodiment of the invention may also be used with any other aspect or embodiment of the invention.

These and other aspects will be apparent from and elucidated with reference to the embodiment(s) described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary Embodiments Will Now be Described, by Way of Example Only, with Reference to the Following Drawings, in which:

FIG. 1 is a schematic view of a fan according to arrangements of the present disclosure;

FIG. 2 is a schematic vertical cross-sectional view of the fan (taken along the line marked II-II in FIG. 1);

FIG. 3 is a schematic cross-sectional view of the fan (taken along the line marked III-III in FIG. 2) according to arrangements of the present disclosure; and

FIG. 4 is a schematic cross-sectional view of the fan (taken along the line marked IV-IV in FIG. 2) according to arrangements of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

With reference to FIG. 1, a fan 100 is shown according to arrangements of the present invention. The fan 100 comprises a housing 1 through which an opening 2 is formed. As shown in FIG. 1, the housing 1 is substantially cylindrical, having a length LH and a width WH and a depth DH. The housing 1 is defined by a substantially cylindrical external surface 30, and two planar end faces 34, 36. As the housing 1 is substantially cylindrical it will be understood that the width WH and depth DH are substantially the same. The length LH is longer than the width WH and depth DH, such that the housing 1 is elongate in the length direction. A centreline or central plane C is defined across the middle of the housing 1 in a horizontal direction which divides the housing 1 in half.

In FIG. 1, the fan 100 is in a vertical position, such that the length LH is in a substantially vertical direction. In the vertical position, the fan 100 rests on a substantially circular end face 34 of the housing 1 and take up a small area of the surface on which it rests. The fan 100 may also be used in a horizontal orientation, in which the length LH is arranged in a horizontal direction. In this orientation, the fan 100 will have a low height profile, making it particularly suitable for use in locations where there is limited vertical space available, such as under a desk. The substantially cylindrical shape of the housing 1 may be slightly flattened to form a plane on which the fan 100 can rest in the horizontal position.

The opening 2 is defined by an inner surface 38 of the housing 1. The inner surface 38 of the housing 1 forms various features of the fan 100 as will be described below. As shown by the arrows in FIG. 1, in use, air passes through the opening 2 in the depth direction when the fan 100 is in use. The air enters the opening 2 at a region that will be referred to as the back 20 of the housing throughout this description, and the air leaves the opening 2 at a region that will be referred to as the front 22 of the housing.

The opening 2 is formed within the housing 1 and is substantially cylindrical, having a depth Do in the direction of the depth DH of the housing 1. The opening 2 is formed through the housing 1 in the depth direction. From a front view, the opening 2 is substantially stadium, or obround shaped, in that it is formed of two semicircles connected by parallel lines at a tangent to their endpoints. The opening 2 through the housing 1 therefore substantially takes the form of a cylinder which has been flattened in the width direction, defining an inner surface 24 of the housing 1 having planar faces 26, 27 and hemicylindrical ends 28, 29. The opening 2 has a length Lo, between the hemispherical ends 28, 29, and a width Wo between the parallel faces 26, 27. The length Lo and the width Wo are each less than the respective length LH and width WH of the housing 1. As seen in FIGS. 3 and 4, the width Wo slightly narrows from the front 22 to the back 20 of the housing 1, such that the opening 2 could be said to be tapered towards the back 20 of the housing 1. As such, the planar faces 26, 27 are not quite parallel.

Referring now to FIGS. 2-4, the housing 1 encloses two independent air flow channels or air flow paths. Each air flow channel comprises an inlet 6, 8, an impeller 4, 11 and an outlet 10, 16. Each air flow channel also passes through air chambers defined by the housing 1. The chambers comprise left and right inlet chambers 13, 5, top and bottom chambers 3, 12 and left and right outlet chambers 9, 15. By providing two separate air flow channels with two independent inlets and impellers, the fan performance can be improved without substantially increasing the size of the fan 100.

Looking at the fan 100 from the front and arranged in a vertical position, as shown in FIG. 2, the first air flow channel or path comprises first inlet 6 and right inlet chamber 5, located at the right hand side of the opening 2, first impeller 4 and top chamber 3 located above the opening 2, and left outlet chamber 9 and first outlet 10, located at the left hand side of the opening 2. The second air flow channel or path comprises second inlet 8 and left inlet chamber 13, located at the left hand side of the opening 2, second impeller 11 and bottom chamber 12 located below the opening 2, and right outlet chamber 15 and second outlet 16 located at the right hand side of the opening. As can be seen from the figures, the air flow channels are arranged to be substantially rotationally symmetrical.

As can be seen in FIGS. 2 and 3, the first and second inlets 6, 8 are arranged on the opposite planar surfaces 26, 27 of the opening 2. The inlets 6, 8 extend along substantially the entire length Lo of the opening 2. The inlets 6, 8 are located towards the back of the opening 2, such that air can be drawn in from the back of the fan 100 in use. In other embodiments, the inlets 6, 8 could be located on the top and bottom end faces 34, 36, or the external surface 30 of the housing.

Filters 7, 14 are located in the inlet chambers 5, 13 behind the inlets 6, 8. The filters 7, 14 remove impurities from the air and enable the fan 100 to act as an air purifier. The addition of filters 7, 14 into the air flow channels, increases the resistance to air flow within the channels. By providing two separate inlets 6, 8 and air flow channels, the performance of the purifier is improved. In other embodiments, the inlet chambers 5, 13 and/or outlet chambers 9, 15 may include filters, heating/cooling elements, and/or humidifiers/dehumidifiers.

As shown in FIGS. 3 and 4, the first and second air outlets 10, 16 each comprise a narrow elongate slit towards a front of the housing 1. The air outlets 10, 16 are formed in the front circumference of the opening 2. The air outlets 10, 16 are therefore located in front of the inlets 6, 8. The air outlets 10, 16 have a curved guiding surface, shaped to provide the Coanda effect, which effectively increases the volume of air which is moved by the fan 100. The flow of air out of the outlets 10, 16 draws air through the opening 2, thus increasing the volume of air which is moved. In addition, the flow of air out of the outlets 10, 16 draws air from around the external surface 30 of the housing 1, thus further increasing the volume of air which is moved.

In FIG. 4, a horizontal cross-section is taken through the first impeller 4, located at the top of the housing 1. As depicted by the arrows, air flows upwards from the right inlet chamber 5, through the impeller 4 in a generally right to left direction and down into the left outlet chamber 9. The first impeller 4 drives the air flow by rotation of a set of impeller blades around an impeller axis A. As shown in FIG. 4, the axis A extends substantially horizontally, in the width direction of the housing 1 so as to move the air in a direction substantially right to left. However, as the inlet chambers 5, 13 and inlets 6, 8 are located towards the back of the housing 1 and the outlet chambers 9, 15 and outlets 10, 16 are located towards the front of the housing 1, the impeller axis 4 is slightly offset from the width direction. As a result, air is moved in a direction having a forwards component, so as to direct the air from the right inlet chamber 5 to the left outlet chamber 9. The impeller axis A is arranged substantially parallel to a plane defined by the width direction and depth direction of the housing 1. In other words, the impeller axis A lies within a plane parallel to central plane C. The impeller 4 is a high speed impeller which provides a smooth air flow. As an impeller is typically longer in its axial direction than its radial direction. This arrangement allows a length dimension of the housing 1 enclosing the impellers to be minimised, and thus the housing 1 can be compact.

By positioning of the air inlets 6, 8 on the inner surface 24 of the housing and providing inlet chambers 5, 13, air can flow from the inlets 6, 8 to the impeller 4, 11 in a smooth curved path. Alternatively, the air inlets 6, 8 may be located on the external surface 30, or end faces of the housing 34, 36. Due to the abrupt corners and thus change in air flow directions, such an air flow would have greater resistance and thus be less efficient. The housing 1 would also be larger to ensure adequate air flow into the inlets 6, 8, if the inlets 6, 8 were located on the external surface 30, or end faces 34, 36 of the housing 1. By providing the inlets 6, 8 on the inner surface 24, smooth and clean external surface 30 and end faces 34, 36 of the housing 1 can be provided and the appearance of the fan 100 is improved.

The impeller 4 is a mixed flow impeller, in which air is input in an axial direction and air is output in a direction having an axial and radial component. Although a detailed view of only the top impeller 4 is shown in FIG. 4, the skilled person would understand that the arrangement of the bottom impeller 11 and the air flow through the bottom impeller 11 would be the reverse of the top impeller 4, i.e., the impeller axis A will be arranged to drive air between the left inlet chamber 13 located towards the back of the housing 1 and the right outlet chamber 15 located towards the front of the housing 1. The arrangement of the impellers 4, 11 in the opposite ends of the housing 1, and the substantially symmetrical positioning of the air flow channels results in an efficient use of space, which means the fan 100 can be more compact whilst having an increase in performance over a single impeller fan system.

The fan 100 also comprises a first and second motor (not shown) arranged to drive the first and second impellers 4, 11 respectively. A user is able to control the motors by means of a switch. In use of the fan 100, a user switches the switch to turn on the power to the first and second motors. The motors drive the first and second impellers 4, 11. As a result, air from the space at the back 20 of the housing 1 is drawn through the inlets 6, 8, into the inlet chambers 5, 13. From the first or right inlet chamber 5, air is drawn upwards into the top chamber 3, and through the first impeller 4. The air then travels out of the first impeller 4 down into the left outlet chamber 9 and out through the first outlet 10. From the second or left inlet chamber 13, air is drawn downwards into the bottom chamber 12 and through the second impeller 11. The air then travels out of the second impeller 11 up into the right outlet chamber 15 and out through the second outlet 16, towards the space in front 22 of the housing 1. Air which is emitted out of the first and second outlets 10, 16 also draws in air through the opening 2, and air passing around the external surface 30 of the housing 1, by the Coanda effect, thus increasing the volume of air which is delivered to the space in front 22 of the fan 100.

Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the principles and techniques described herein, from a study of the drawings, the disclosure and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfil the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. A computer program may be stored or distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. Any reference signs in the claims should not be construed as limiting the scope.

Claims

1. A fan comprising: a housing whose inner surface defines an opening which extends through the housing, wherein the fan is configured such that, in use, air flows through the opening from a back to a front of the housing;a first air flow channel defined within the housing, comprising a first air inlet, a first air outlet and a first impeller for driving air from the first inlet to the first outlet; anda second air flow channel defined within the housing, comprising a second air inlet, a second air outlet and a second impeller for driving air from the second inlet to the second outlet,wherein the first and second air outlets are configured to draw air through the opening, are located towards the front of the housing, and the first and second air inlets are located towards the back, andwherein the first and second air inlets are located on the inner surface of the housing.

2. The fan of claim 1, wherein the housing defines a centreplane (C), and wherein the first impeller is on one side of the centreplane and the second impeller is on the other side of the centreplane.

3. The fan of claim 2, wherein the first and second impellers (4, 11) have a rotation axis (A), and the first and second impellers are arranged such that the rotation axes are parallel with the centreplane.

4. The fan of claim 1, wherein the housing comprises an elongate housing, the first impeller being adjacent a first end of the elongate housing, and the second impeller being adjacent a second end of the elongate housing, opposite the first end.

5. The fan of claim 1, wherein the housing is substantially cylindrical.

6. The fan of claim 1, wherein the first air flow channel includes a right inlet chamber located at a right hand side of the opening, a top or bottom chamber of the first air flow channel respectively located above or below the opening, and a left outlet chamber located at a left hand side of the opening, and wherein the second air flow channel includes a left inlet chamber located at the left hand side of the opening, a bottom or top chamber of the second air flow channel respectively located below or above the opening and opposite the top or bottom chamber of the first air flow channel, and a right outlet chamber located at the right hand side of the opening.

7. The fan of claim 6, wherein the first and second inlets are located at opposite sides of the opening.

8. The fan of claim 1, wherein at least one of the first and second air flow channels comprises a filter.

9. The fan of claim 8, wherein the filter is located between the air inlet and the impeller.

10. The fan of claim 1, wherein at least one of the first and second air flow channels comprises at least one of a heating element and a humidifier.

11. The fan of claim 1, wherein the first and second air outlets each comprise a curved guiding surface.

12. The fan of claim 1, wherein the first and second air outlets further comprise a slit shaped outlet.

13. The fan of claim 1, wherein the first and second air outlets are located at opposite sides of the opening.