AIR PURIFIER

Abstract

 An air purifying device (10, 40) comprises a housing (16) with a first inlet (35) and an outlet (37); a filter (14) within the housing (16) and adjacent to the first inlet (35); a second inlet (28) in the housing; a fan (12) within the housing to direct air from the first inlet (35) and/or the second inlet (28) to the outlet (37); and means for selectively opening or closing the second inlet (28).

Description

Field of the invention

[0001] The present invention relates to an air purifying device and more particularly to an air purifying device for homes that may be operated in either the fan mode or air purifying mode.

Background of the invention

[0002] Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of the common general knowledge in the field.

[0003] Due to increasing industrialization, increase in vehicular traffic, etc.; air pollution is becoming more prevalent. This is, in some cases, causing damage to people's health due to various respiratory diseases. Apart from this, harmful air borne bacteria, fumes and gases, high formaldehyde levels and dust allergens are also becoming a concern. Eliminating airborne bacteria and particles in homes and other small buildings is a goal that is not easily accomplished. Dust can easily lead to respiratory diseases; and when inhaled, high concentrations of formaldehyde can lead to severe irritation and edema, eye irritation, and irritation of the respiratory tract. This may also lead to bronchial asthma. Therefore, a lot of effort has been directed to ensure the cleanliness of indoor air.

[0004] In an attempt to cope with the increasingly serious pollution, many new air purifying devices have been introduced in the market.

[0005] An indoor air purifier, which cleans up pollutants inside homes, generally consists of a series of filters to remove the pollutants. The filters include High Efficiency Particulate Arrestance (HEPA) Filters and Activated Carbon (AC) filters in combination with a centrifugal fan, which collects the polluted air from the room and passes it through the filters. Recently, air filters have been designed which can be fitted to an existing axial fan, and the filter and fan assembly then works as an air purifier. Such a system can be seen in WO 2009/010528. One of the drawbacks of either a conventional air purifier with a blower or that of the purifiers where filters are attached to an axial fan is that, in the presence of some filters, such as High Efficiency filters, the flow rate of the fan comes down, for example, by more than 75%. Hence, the device is no longer very efficient or effective for use as a regular fan, with the flow rates lower than conventional table and ceiling fans. There are some air purifier devices in the market which provide high flow rate with the help of a high power motor for the fan. However, this leads to higher noise and higher energy consumption.

[0006] CN2135740 (1993), discloses an indoor air purifying fan that comprises an outer shell, blades of a ventilating fan, a miniature motor and a purifying and filtering core. The purifying and filtering core includes purifying and filtering meshes made of fibrous activated carbon materials. After the air passes through the purifying and filtering core, harmful particles, any viruses, and odour are absorbed by the filtering materials and thus, the air is then purified. CN1721046 (2006) also discloses an air cleaning fan with multiple filtering layers. KR20120041315 (Hong Eun Soo, 2012), discloses an electric air purifying fan to maintain clean indoor air by providing triple air purifiers including an oxygen purifying filter, a honeycomb-shaped filter, and an air purifying filter. These air purifying fans will function only as air purifiers and cannot act as a conventional fan to provide high rates of air flow as the filters will reduce the passage of air.

[0007] Some air purifiers have introduced systems which allow for the filter to be shifted from its normal position perpendicular to the flow path for when levels of contamination are determined to be sufficiently low. Such a system is shown in EP 1434012 A2. In this system, the filter can be opened by rotating or sliding so that the flowpath is at least partially open. However, in such a system, air still travels by the filter, which can cause dust and other particles collected in the filter to dislodge and flow into the airstream. This is particularly prone to happen when the filter is rotated to be parallel to the air flow path through the air purifier.

Summary of the invention

[0008] According to a first aspect of the invention, an air purifying device comprises a housing with a first inlet and an outlet; a filter within the housing and adjacent to the first inlet; a second inlet in the housing; a fan within the housing to direct air from the first inlet and/or the second inlet to the outlet; and means for selectively opening or closing the second inlet.

[0009] By including a first inlet which direct air through the filter, a second inlet which allows air to bypass the filter and means for selectively opening or closing the second inlet, a second air path may be formed through the device which bypasses the filter and allows the device to be used as a conventional fan. Such an arrangement provides a compact, efficient and easy to use device that may act as an air purifying device or a simple fan depending on current needs, and eliminates the need to have separate devices for air purifying and for simple fan based air flow. Being able to run the device in either air purifier mode or fan mode may additionally help the user save energy as compared to running the device continuously in air purifier mode or running two devices.

[0010] According to a preferred embodiment, the second inlet comprises a plurality of second inlets in the housing which may be selectively opened or closed. Including a plurality of second inlets allows for easy entry of air into a second flow path for the device to operate in fan mode without having to pull air through the filter, which can result in a slowdown of air and/or noise from the air flowing through the filter or the fan motor having to work harder to pull the air through the filter.

[0011] According to a preferred embodiment, the means for selectively opening or closing the second inlet comprises one or more rotatable louvres. Alternatively, these may be doors, covers or anything else that can effectively open or seal one or more second inlets. This allows for or prevents air into the device through the second inlet, thereby determining whether the device is operating in an air purifying mode or in a fan mode.

[0012] According to a preferred embodiment, the fan is an electric motor driven fan. Such a fan may act well for the device to operate as a conventional fan or as an air purifier.

[0013] According to a preferred embodiment, when the second inlet is open, most of the airflow through the housing flows in the second inlet and out the outlet. This allows air to bypass the filter, making the fan work efficiently as a conventional fan. This also avoids the noise and slowed airflow that flowing through the filter may cause when air purifying is not necessary. Additionally, avoiding air flow through the filter may help preserve the life of the filter and overall system, only requiring the additional work and air flow through the filter when necessary.

[0014] According to a preferred embodiment, the device further comprises a sensor to sense the air quality. Sensing air quality allows the device to provide feedback on air quality, thereby making for a more efficient overall system. Where the change between air purifying mode and fan mode is automatic, the sensor may send a signal to change between modes as soon as air purifying is no longer needed. When changing modes is done manually, the sensor may indicate to a user, for example, visually or audibly, when a change is needed. Thus, a sensor may ensure that a change in mode is performed as soon as necessary, or that a user knows when to change no matter the length of usage, current conditions, etc. Optionally, the sensor is a particle and/or a gas sensor. Further optionally, the particle and/or gas sensor is selected from volatile organic chemical sensors, inorganic gas sensors, and malodour sensors.

[0015] According to a preferred embodiment, the means for selectively opening or closing the second inlet comprises one or more of mechanical, electrical and electromechanical switches. Such switches easily and simply open or close the second inlet to allow a simple switch between air purifying and fan modes. These one or more switches work to operate louvers, doors, etc. which selectively cover or seal the second inlet(s).

[0016] According to a preferred embodiment, the filter is a particulate and/or gas filter. Optionally, the particulate and/or gas filter is selected from one or more of a MERV filter; a HEPA filter; a ULPA filter; a coarse washable filter; a nylon filter; an aluminum mesh filter; an adsorption filter and a catalytic filter.

[0017] According to a preferred embodiment, the housing is a rectangular shape with the first inlet opposite the outlet, and the second inlet comprises one or more second inlets on one or more sides of the housing. This arrangement works well to provide a compact device that may operate as an air purifying device or as a conventional fan, and could possibly use many conventional fan parts for manufacture. Such a device would even resemble a conventional fan.

[0018] According to a preferred embodiment, the means for selectively opening or closing the second inlet comprises one or more of a cover, a switch, a latch and a louvre. These may be operated manually, electrically, or through a number of other means in the art. They would allow for easy and effective covering or opening of the second inlet(s) to promote either air purifying mode with an air flow path through the air filter or fan mode with an air flow path through the second inlet(s) (and little to no air entering and flowing through the filter).

[0019] According to a preferred embodiment, the second inlet is located adjacent to the first inlet. This set-up allows for a very compact device. This setup could also work well when the desired air for either filtering or fan flow is in or coming from a certain area.

[0020] According to a second aspect of the invention, a method of forming an air purifying device comprises forming a housing with a first inlet, a second inlet and an outlet; connecting a fan inside the housing to direct airflow from the first inlet and second inlet to the outlet; and arranging means for selectively covering the second inlet to not allow air flow through the second inlet, wherein the air purifying device can receive a filter at or near the first inlet. Such a method forms a compact and efficient device which may operate in an air purifying mode or in a conventional fan mode. The method forms a device with sufficient clearance between the filter and the fan for an air path to flow from the second inlet to the outlet without flowing through the filter. This clearance may be, for example, about 25-50% of the width of the filter to allow for a second airflow path without adding too much bulk to the fan and being large enough that too much additional noise is not created from the air flow through this path.

Short description of drawings

[0021] The present invention will be discussed in more detail below, with reference to the attached drawings, in which

Fig. 1 a shows a perspective front view of a first embodiment of an air purifying device.

Fig. 1b shows a perspective side view of the air purifying device of Fig. 1 a.

Fig. 1c shows a perspective back view of the air purifying device of Fig. 1 a.

Fig. 1d shows a cross-sectional view of the air purifying device of Fig. 1 a.

Fig. 1e shows a side perspective view of the air purifying device of Fig. 1 a with a louver opened.

Fig. 1f shows a back view of the air purifying device of Fig. 1a with two louvers opened.

Fig. 2a shows a perspective view of a second embodiment of an air purifying device with a second inlet closed.

Fig. 2b shows a perspective view of the air purifying device of Fig. 2a with the second inlet open.

Detailed description of the invention

[0022] Fig. 1 a shows a perspective front view of a first embodiment of an air purifying device 10. Fig. 1b shows a perspective side view of air purifying device 10, Fig. 1c shows a perspective back view of air purifying device 10, Fig. 1d shows a cross-sectional view of air purifying device 10, Fig. 1e shows a side perspective view of air purifying device 10 with a louver 11 opened, and Fig. 1f shows a back view of air purifying device 10 with two louvers 11 opened.

[0023] Air purifying device 10 contains a conventional motor-driven fan 12 and filter 14 inside housing 16. Housing 16 includes front 18, back 20 and sides 22, top 24 and base 26. Sides 22, top 24 and base 26 form a perimeter around air purifying device 10 housing 16. Each side 22 includes louver 11 covering second inlet 28 and latch knob 27. Top includes sensor 30 and control buttons 32, though they could be located at different positions (e.g., on a different side of housing 16) in different embodiments. Airflow is shown by arrows 34.

[0024] Back 20 acts as a first inlet 35 for air purifying device 10, and second inlets 28 are exposed by opening louvers 11. Front 18 is the outlet for air purifying device 10. As can be seen, there is clearance between where filter 14 is located at or near back 20 of housing 16, and where fan 12 is located at or near front 18 of housing 16. This allows for a separate air flow path from second inlets 28 through outlet at back 20. This clearance may be, for example, about 25-50% of the width of the filter 14 to allow for a sufficient second airflow path without adding too much bulk to the fan and being large enough that too much additional noise is not created from the air flow through this path.

[0025] Filter 14 may be one or more filters 14 for removing particles, gas, contaminants and/or other things from the air. For example, filter 14 could comprise one or more of a MERV filter; a HEPA filter; a ULPA filter; a coarse washable filter; a nylon filter; an aluminium mesh filter; an adsorption filter and a catalytic filter.
Sensor 30 may be a number of types of sensors, including particle and/or gas sensors, for example, volatile organic chemical sensors, inorganic gas sensors, malodour sensors. Sensor 30 may also be located in a different position than shown and/or additional sensors could be present, located near sensor 30 or at a different location. Control buttons 32 may also include a switch, which may be, for example, a mechanical, electrical or electromechanical switch. The switch may operate to open or close louvers 11 for allowing or preventing airflow through second inlets 28. In lieu of a switch or in addition to a switch, louvers 11 could be manually opened or closed, for example, using latch knobs 27.

[0026] Air purifying device 10 is able to work in an air purifying mode or in a fan mode. Air purifying mode consists of airflow entering the device 10 through first inlet 35 at the back 20 of housing 16. Louvers 11 are both closed, so that virtually no air is allowed in through second inlets 28 on sides 22 of housing 16. Fan 12 causes air to flow in first inlet 35 through filter 14, where one or more filters clean the air, removing contaminants and particles from the air flow. Fan 12 rotation continues to pull air in first inlet 35 and direct the airflow out the front 14 of air purifying device 10.

[0027] In fan mode, louvers 11 are opened so that second inlets 28 are exposed. Because the air resistance is much lower through second inlets 28 than through filter 14, most air will flow into air purifying device 10 through second inlets 28 in sides 22 of housing 16 (bypassing filter 14) in this mode. The lower air resistance will also cause a higher flow rate for air purifying device 10 to operate as a conventional fan.

[0028] Sensor(s) 30 and control buttons 32 may preferably be used to make the transitions from air purifying mode to fan mode and vice versa. For example, sensor 30 could sense when the air in a room has reached a level of sufficient purification (e.g., the contaminants sensed in the air have dropped below a predetermined level). When sensor 30 senses this state, it could send a signal to the switch to open louvers 11, allowing air purifying device 10 to operate in fan mode. Air purifying device 10 could continue operating in fan mode until sensor 30 senses a level of contamination that is above a predetermined level, and then proceed to send a signal to close louvers 11, forcing air to flow through filter 14 again. Sensor(s) 30 could also sense things such as when filter 14 is overly contaminated, and needs to be changed, signalling device 10 to shut down or only operate in fan mode until such a change has occurred. In some embodiments, a sensor 30 may simply indicate that a switch is needed between modes of operation, for example, with a sound or light, and that switch between modes can be performed manually by a user. Sensor could also be used to control the fan speed in some embodiments.

[0029] By having one or more second inlets 28 that are able to be opened or closed and an air flow path that is able to bypass filter 14, air purifying device 10 is able to operate in an air purifying mode or in a fan mode. This allows for a compact and easy to use device 10 that is able to perform two different functions depending on current conditions. As mentioned in the background, past conventional fans were sometimes able to work as air purifying devices by connecting a filter in the air flowpath. While this provided a way to purify air with a conventional fan, the flow through the filter greatly slowed down the airflow, causing the device to not be usable as a conventional fan without removing the filter or having a large motor (to compensate for the drag through the filter) that would cause a great deal of noise. The use of a second flow path, in this embodiment, formed with louvers 11 on sides 22 that are able to open or close, provides a compact and effective device that may be used as an air purifier or a conventional fan. This is helpful to preserve the life of the filter and the overall system, as the filtering flowpath (and the additional work the fan motor must to provide to pull the air through that flowpath) is only used when necessary.

[0030] Additionally, the use of one or more sensors which are able to provide feedback on air quality may make for an overall more efficient system. Where the change between air purifying mode and fan mode is automatic, sensor(s) 30 may automatically send signals for the change. Where change between modes is manual, sensor(s) 30 may indicate when a change is needed so a user may be assured the air purifying device 10 is in the desired mode no matter the current conditions, length of usage, etc.

[0031] Fig. 2a shows a perspective view of a second embodiment of an air purifying device 40 with a second inlet 28 closed, and Fig. 2b shows a perspective view of air purifying device 40 with second inlet 28 open. Similar parts are labelled with similar reference numbers to Figs. 1a-1f. Air purifying device 40 is similar to a conventional tower fan, and in some embodiments could rotate similar to some conventional tower fans.

[0032] Figs. 2a-2b include air purifying device 40 with louver 11, fan 12, filters 14, housing 16 (with top 24 and base 26), first inlets 35, second inlet 28, sensor 30, control buttons 32, airflow arrows 34 and outlet 37.

[0033] Filters 14 sit at or near first inlets 35, and fan 12 sits within housing 16 pulling air into air purifying device 40 and directing it toward and through outlet 37. In air purifying device 40, second inlet 28 is located on the same side of housing 16 as first inlets 35. Louver 24 opens to allow air in through second inlet 28.

[0034] Air purifying device 40 operates in the same manner as air purifying device 10, being able to operate as an air purifier when louver 24 is closed, and as a conventional fan when louver 24 is opened. In this embodiment, each of first inlets 35 and second inlet 28 are located on the same side of housing 16. Thus, the flow path into housing 16 remains similar no matter the operational mode. As in the embodiment shown in Figs. 1a-1f, the change in operational mode may be automatic or manual, and may be based on feedback from sensor 30, which may include current air quality readings.

[0035] Air purifying devices 10,40 act as a simple, easy to use and efficient device which may operate to purify air or operate as a conventional fan. This eliminates the need to have two separate devices for the purifying and regular air circulation, or a higher power setting on the fan motor to pull sufficient airflow through the filter to operate as a conventional fan. This may be especially useful in home or smaller room environments where space is a premium. The ability to open second inlet(s) 28 to allow air to bypass filter when entering device 10, 40 allows for use of a standard fan and motor while providing sufficient airflow through the outlet. Including one or more sensors allows for better control of the system, either automatically or by providing a cue so that a user may easily ascertain when a certain desired setting is reached and the mode of operation should be changed. Additionally, by being able to run air purifying device 10, 40 either in the air purifier mode or fan mode based on the air quality, a user saves energy as compared to running it continuously in an air purifier mode

[0036] While the embodiments shown resemble conventional house or room fans and tower fans, other embodiments could resemble other types of conventional fans, for example, a ceiling fan. Similarly, while a number of filter options were disclosed, any type of filter could be used with system 10, 40.

[0037] While one or more louvers are shown which allows for selectively opening or closing second inlet(s) 28, other means could be used. For example, a sliding cover, another type of cover or switch, a plurality of louvers or covers, and other such means which could allow for air into second inlet(s) or make second inlet(s) such that little to no air is able to flow in. Additionally, more or fewer louvers could be used to cover more or fewer inlets.

[0038] While the invention has been described with reference to exemplary or preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular or preferred embodiments or preferred features disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

1. An air purifying device (10, 40) comprising:

a housing (16) with a first inlet (35) and an outlet (37);

a filter (14) within the housing (16) and adjacent to the first inlet (35);

a second inlet (28) in the housing;

a fan (12) within the housing to direct air from the first inlet (35) and/or the second inlet (28) to the outlet (37); and

means for selectively opening or closing the second inlet (28).

2. The air purifying device (10) as claimed in claim 1, wherein the second inlet (28) comprises a plurality of second inlets in the housing which may be selectively opened or closed.

3. The air purifying device (10, 40) of any of the preceding claims, where the means for selectively opening or closing the second inlet (28) comprises one or more rotatable louvres (11).

4. The air purifying device (10, 40) of any of the preceding claims, wherein the fan (12) is an electric motor driven fan.

5. The air purifying device (10, 40) of any of the preceding claims, wherein when the second inlet (28) is open, most of the airflow through the housing flows in the second inlet (28) and out the outlet (37).

6. The air purifying device (10, 40) of any of the preceding claims, and further comprising a sensor (30) to sense the air quality.

7. The air purifying device (10, 40) of claim 6, wherein the sensor (30) comprises a particle and/or a gas sensor.

8. The air purifying device (10, 40) of claim 7, wherein the particle and/or gas sensor comprises one or more of volatile organic chemical sensors, inorganic gas sensors, malodour sensors.

9. The air purifying device (10, 40) of any of the preceding claims, wherein the switch means for selectively opening or closing the second inlet comprises one or more of mechanical, or electrical and or electromechanical switches.

10. The air purifying device (10, 40) of any of the preceding claims, wherein the filter (14) is a particulate and/or gas filter.

11. The air purifying device (10, 40) of claim 10, wherein the particulate and/or gas filter comprises one or more of a MERV filter; a HEPA filter; a ULPA filter; a coarse washable filter; a nylon filter; an aluminium mesh filter; an adsorption filter and a catalytic filter.

12. The air purifying device (10, 40) of any of the preceding claims, wherein the housing (16) is a rectangular shape with the first inlet (35) opposite the outlet (37), and the second inlet (28) comprises one or more second inlets (28) on one or more sides of the housing (16).

13. The air purifying device (10, 40) of any of the preceding claims, wherein the means for selectively opening or closing the second inlet (28) comprises one or more of a cover, a switch, a latch and a louvre.

14. The air purifying device (10, 40) of any of the preceding claims, wherein the second inlet (28) is located adjacent to the first inlet (35).

15. A method of forming an air purifying device (10, 40), the method comprising:

forming a housing (16) with a first inlet (35), a second inlet (28) and an outlet (37);

connecting a fan (12) inside the housing such that the fan may direct airflow from the first inlet (35) and/or the second inlet (28) to the outlet (37); and

arranging means for selectively covering the second inlet (28) to not allow air flow through the second inlet (28), wherein the air purifying device may receive a filter (14) at or near the first inlet (35).

Drawing