SE2030153A1

SE2030153A1 - Air purifier

Info

Publication number: SE2030153A1
Application number: SE2030153A
Authority: SE
Inventors: Andreas Murray
Original assignee: Livsdal Sverige Ab
Priority date: 2020-05-07
Filing date: 2020-05-07
Publication date: 2021-11-08
Also published as: SE546141C2

Abstract

An air purifier (1) is disclosed. The air purifier (1) comprises a housing (2); an air inlet (3) arranged on a first side (4) of the housing (2); an air outlet (5) arranged on a second side (6) of the housing (2); an air channel (7) extending from the air inlet (3) to the air outlet (5); a fan (8) arranged in the air channel (7) between the air inlet (3) and the air outlet (5); at least one filter (9, 15, 17) configured to filter particles from the passing air. The filter (9, 15, 17) is arranged between the air inlet (3) and the air outlet (5). Wherein a ratio between an area of the air outlet (5) and an area of the air inlet (3) is smaller than a threshold limit (a), which threshold limit is smaller than 0.5.

Description

TECHNICAL FIELD This document discloses an air purifier. More particularly, an air purifier is disclosed, for eliminating various particles such as traffic emissions, viruses, bacteria, toxic molecuies, gases and other harmful particles from the air of a room in an effective, yet gentle way.

BACKGROUND lt is known that various impurities and harmful particles in the air may present a health hazard and may cause sickness of humans and/ or animals. An example may be emissions from traffic and/ or energy production which pollutes the air and may cause health problems also in an indoor environment situated for example in a large city or close to a highway. Another example may be pollen, dust mites and/ or mold spores that may trigger allergic reactions among sensitive people. Yet an example may be viruses, bacteria, toxic molecuies, and/ or various gases in the air, that may present a health hazard.

Various devices and arrangements are known for separating particles from the air in an in- door environment, often referred to as air purifiers. Such air purifiers may for example be used in isolation rooms in hospitals, in operating rooms, in offices, in private homes, etc.; generally, air purifiers may be utilised in any indoor environment where air pollution is undesired. lt is often desired to install an air purifier which is separate from any inbuilt ventilation and/ or air conditioning system. For targeting these desires, stand-alone air purifiers have been developed.

A problem that has been observed among previously known air purifiers is that they typically are not successful in bringing the air of the room in circulation, passing through the air puri- fier. instead, the filtered air has a tendency to just slip from the output side of the air purifier to the input side, thereby causing the air purifier to circulate substantially the same air through the air purifier multiple times, making a negligible or at least insufficient contribution to the overall air purity of the room as a whole.

Another problem of previously known air purifiers is that they emit undesired noise due to a fan used in the air purifier to guide the air through the air purifier filter. Even if the noise per se may be modest in comparison with other noise sources, the experienced noise pollution by the human may be perceived as disturbing as a room typically comprises a plurality of 2 different noise sources in form of fans, ventilation/ heat system, refrigerator/ freezer com- pressor, kitchen hood, cooling fan of computers, etc., in addition to intentionally applied sounds from talking people in the room, music player, TV, gaming device, etc., and possibly also room-external environmental noise from traffic, work related activities, human commu- nication, etc. lt is for these reasons desired to develop an improved air purifier, solving at least some of the above-mentioned disadvantages, enabled to provide clean air in a superior way.

SUMMARY lt is therefore an object of this invention to solve at least some of the above problems and improve air purification of an indoor environment.

According to an aspect of the invention, this objective is achieved by an air purifier configured to purify air of a room. The air purifier comprises a housing. The air purifier also comprises an air inlet arranged on a first side of the housing, and an air outlet arranged on a second side of the housing. ln addition, the air purifier also comprises an air channel extending through the housing from the air inlet to the air outlet. The air purifier in addition comprises a fan arranged in the air channel between the air inlet and the air outlet. Furthermore, the air purifier also comprises at least one filter configured to filter particles from the passing air, which filter is arranged between the air inlet and the air outlet. The ratio between an area of the air outlet and an area of the air inlet is smaller than a threshold limit, which threshold limit is smaller than 0.5.

Thanks to the described aspects, by applying an area of the air outlet which is relatively small, much smaller than an area of the air inlet, the air passing through the air purifier is allowed to enter the air inlet and pass an inlet filter at a low speed, while the output air is ejected out in the room at a much higher speed, thereby avoiding that the same air is itera- tively circulated from the air outlet to the air inlet of the air purifier. Another advantage is that a relatively large filter size may be used for e.g. a pleated flat-plate filter applied close to the air inlet.

A pleated flat-plate filter comprises only a small amount of air filtering material, as the pleated flat-plate filter typically is rather thin, e.g. some millimetres. By using a large air inlet, it be- comes possible to mount a large pleated flat-plate filter inside the air inlet, bringing two ad- vantages. Firstly, a large pleated flat-plate filter has a longer service life than a small pleated flat-plate filter, due to the added amount of adsorptive material. Secondly, the large air inlet 3 leads to the air passing the large pleated flat-plate filter at a relatively low speed, leading to an extended transit time through the filter material, in comparison with a smaller pleated flat- plate filter, leading to a more effective separation of impurities from the air.

Hereby, air purification of an indoor environment is improved by the provided air purifier.

Other advantages and additional novel features will become apparent from the subsequent detailed description.

FIGURES Embodiments of the invention will now be described in further detail with reference to the accompanying figure.

Figure1 illustrates an example of an air purifier according to an embodiment of the invenüon. Figure 2 illustrates an example of an air purifier with an air deflector according to an embodiment of the invention.

Figure 3 illustrates an example of an air purifier comprising an air channel comprising at least one perpendicular turn according to an embodiment of the invention.

Figure 4 illustrates an example of an air purifier comprising an air channel having a quadrilateral/ rectangular cross section according to an embodiment of the invenüon.

Figure 5 illustrates an example of an air purifier wherein at least a part of the interior of the air channel comprises sound absorbing elements.

Figure 6 illustrates an example of an air purifier having air inlet on a lateral side of the housing and air outlet on a top side of the housing according to an embodi- ment of the invention.

Figure 7 illustrates an example of an air purifier wherein the top side of the housing is detachable according to an embodiment of the invention.

Figure 8 illustrates an example of an air purifier comprising at least one cylindrical coal filter according to an embodiment of the invention.

Figure 9 illustrates an example of an air purifier comprising an easily exchangeable cylindrical coal filter according to an embodiment of the invention.

Figure 10 illustrates an example of an air purifier comprising an ultraviolet light source illuminating the outside of a filter according to an embodiment of the invention.

DETAILED DESCRIPTION 4 Embodiments of the invention described herein are defined as an air purifier, which may be put into practice in the embodiments described below. These embodiments may, however, be exemplified and realised in many different forms and are not to be limited to the examples set forth herein; rather, these illustrative examples of embodiments are provided so that this disclosure will be thorough and complete.

Still other objects and features may become apparent from the following detailed description, considered in conjunction with the accompanying drawings. lt is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the herein disclosed embodiments, for which reference is to be made to the appended claims. Further, the drawings are not necessarily drawn to scale and, unless oth- en/vise indicated, they are merely intended to conceptually illustrate the structures and pro- cedures described herein.

Figure 1 illustrates a cross-section view of an air purifier 1. The air purifier 1 may be a stand- alone product, or inbuilt into, or form part of, a ventilation system/ air conditioning system in different embodiments. However, the illustrated embodiment and the subsequent description primarily address the air purifier 1 as a stand-alone product for indoor usage.

The air purifier 1 comprises a housing 2 or cabinet which encloses at least some of the entities of the air purifier 1. The housing 2 may be made of metal, plastic, wood, fibre board such as e.g. l\/ledium-Density Fibre board (l\/IDF) board or other similar appropriate material. Different parts of the housing 2 may be made of different materials; for example, the bottom may be made of metal such as steel or aluminium, the backside of the housing 2 may be made of plastic, the other sides may be made of MDF board and the top may be made of stone such as marble, granite, etc.

The housing 2 may be configured to stand on a floor. An underneath side of the housing 2 may comprise a set of vibration absorbers, configured to let the housing 2 rest on the floor, reducing transmitted noise/ vibrations. Alternatively, the underneath side of the housing 2 may comprise a set of wheels, facilitating movement of the air purifier 1.

However, in other embodiments, the housing 2 of the air purifier 1 may be integrated into a furniture, or into a ventilation system or an air conditioning system. ln yet other embodiments, the housing 2 may be configured to be mounted on a wall or ceiling.

The air purifier 1 also comprises an air inlet 3 arranged on a first side 4 of the housing 2 and an air outlet 5 arranged on a second side 6 of the housing 2. The first side 4 may be distinct from the second side 6. ln some embodiments, the first side 4 may comprise a lateral side 12 of the housing 2, such as a back side. The second side 6 may comprise a top side 13 of the housing 2, see Figure 6. ln yet some embodiments, the first side 4 may be opposite to the second side 6 of the housing 2. ln other embodiments, the air inlet 3 may be arranged on a p|ura|ity of lateral sides 12 of the housing 2 while the air outlet 5 is arranged on the top side 13 of the housing 2.

Further, the air purifier 1 comprises an air channel 7 extending through the housing 2 from the air inlet 3 to the air outlet 5, thereby guiding the air through the air purifier 1.

The air channel 7 may be configured to reduce noise created by a fan 8 arranged in the air channel 7, between the air inlet 3 and the air outlet 5, while guiding the air from the air inlet 3 to the air outlet 5.

The fan 8 may be for example an axial flow fan, a centrifugal fan, a cross flow fan, an air mu|tip|ier or similar device for propagating air through the air channel 7. ln some embodiments, the air channel 7 may comprise at least one approximately perpen- dicular turn between the air inlet 3 and the air outlet 5, see Figure 3. Hereby, noise created by the fan 8 is forced to reflect against a wall of the air channel 7 before reaching at least one of the exits 3, 5 of the air channel 7. Thereby, energy is lost, which reduces the noise level output by the air purifier 1. ln some embodiments, one approximately perpendicular turn may be situated between the fan 8 and the air inlet 3 and yet one approximately per- pendicular turn situated between the fan 8 and the air outlet 5.

The air channel 7 may have a quadrilateral/ rectangular cross section in some embodiments to reduce emitted noise of the fan 8, as illustrated in Figure 4. By the rectangular cross section of the air channel 7, soundwaves are brought into irregular reflections between the walls of the air channel 7, in comparison with for example an air channel 7 having a circular cross section, which reduces energy and thereby also the emitted noise level. Figure 5 illustrates an embodiment wherein, at least a part of the interior of the air channel 7 may comprise sound absorbing elements 11, absorbing energy from sound waves emitted by the fan 8, thereby reducing the output noise level of the fan 8.

The sound absorbing elements 11 may be made of a porous material such as for example a 6 layer of fibrous material configured to absorb a sound since a sound wave is able to pene- trate its surface where it gets bended and dampened and then converted into heat energy. Thereby, acoustic energy is converted into heat energy where most of the sound is absorbed into heat, thereby reducing emitted noise.

The sound absorbing elements 11 may also, or alternatively comprise open-celled foam, which absorbs a sound by the air movement of the sound waves through passages of the material. As a result, the noise of the fan 8 is reduced. The thicker the material, the greater impact it has on sound/ noise absorption. ln yet some embodiments, the sound absorbing elements 11 may comprise panel absorbers situated within the air channel 7, reflecting sound waves towards walls of the air channel 7 and other panel absorbers. Each impact will reduce the energy of the sound wave, thereby reducing emitted noise.

The sound absorbing elements 11 may in some embodiments comprise resonance absorb- ers/ sound baffles, reducing strength (level) of the fan noise.

The interior of the air channel 7 may in some embodiments comprise cavities or chambers, absorbing energy from sound waves passing the air channel 7, much like a silencer for a firearm. ln some embodiments, the sound absorbing elements 11 of the air channel 7 may be con- figured to cause destructive interference, i.e. frequency shifting and phase cancellation. The destructive interference is created by duplicating sound waves generated by the fan 8, which then are used to create an anti-phase auditory signal, thereby extinguishing, or at least re- ducing emitted sound waves of the fan 8.

The air purifier 1 comprises at least one filter 9 configured to filter particles from the passing air, which filter 9 is arranged in the air channel 7 between the air inlet 3 and the air outlet 5.

The at least one filter 9 may comprise a set of inlet filters 9 arranged in the air channel 7 between the air inlet 3 and the fan 8, for example at/ just inside the air inlet 3.

The set of inlet filters 9 may comprise a prefilter configured to catch regular dust and large particles such as certain species of pollen, followed by one or several particle filters 9 such as a High-Efficiency Particulate Air (HEPA) filter, or a Ultra-Low Particulate Air (ULPA) filter.

The prefilter and/ or the particle filter 9 may be made from a fibrous or porous material such as paper, polyurethane foam, cotton, etc., which removes solid particulates such as dust, pollen, mold, and bacteria from the air. The inlet filter/-s 9 may also, or alternatively comprise an adsorbent or catalyst such as charcoal (carbon) which may also remove odours and gas- eous pollutants such as volatile organic compounds or ozone.

Hereby, indoor air quality of a room wherein the air purifier 1 is situated is increased as particles and contaminants are filtered out from the air passing the air purifier 1. Various allergens are filtered out, for the obvious benefit of allergic users. Also, health hazardous particles are filtered out, such as asbestos, impurities in tobacco smoke or combustion of other burning material. Bacteria and virus are also extracted from the passing air.

The at least one filter 9 of the air purifier 1 may alternatively comprise a set of outlet filters 15, 17 arranged in the air channel 7 between the fan 8 and the air outlet 5.

The set of outlet filters 15, 17 may comprise at least one carbon molecule filters 15, 17, or coal filters as they also may be referred to as. The coal filter/-s 15, 17 is/ are configured to absorb odours, gases and various emissions comprising nitrogen dioxide, sulphur dioxide, ozone, formaldehyde, etc. ln some embodiments, the set of outlet filters 15, 17 may also comprise a post filter, com- prising a metal granular-filter or a pleated particle filter, configured to capture any carbon particles that could potentially be released by the coal filter 15, 17.

The at least one filter 9 of the air purifier 1 may be configured to filter particles from the passing air without previous treatment of the air by ultraviolet light within the air purifier 1.

However, in some alternative embodiments, the housing 2 of the air purifier 1 may comprise a device for emitting ultraviolet light onto air flowing through the air channel 7. This may sometimes be referred to as Ultra-Violet Germicidal lrradiation (UVGI), a disinfection method that uses short-wavelength ultraviolet light to kill or inactivate microorganisms by destroying nucleic acids and disrupting their DNA, leaving them unable to perform vital cellular func- tions. An example of the latter is illustrated in Figure 10, where an ultraviolet light source 20 illuminates the outside of a filter 9 according to an embodiment of the invention. Hereby, amount of virus, germs, pollen, etc., that has been captured by the filter 9 could easily be observed. Based there upon, it could be determined whether it is time to exchange the filter 9 or not.

The air purifier 1 has a ratio between an area Aout of the air outlet 5 and an area Am of the air in|et 3 is smaller than a threshold limit oi, which threshold limit oi is smaller than 0.5, i.e.: Aout: a< A , where oi <0.5. in By having an area Aoul of the air outlet 5 which is half the size of the Am of the air in|et 3, the speed of the air leaving the air purifier 1 through the air outlet 5 becomes higher than the air entering the air in|et 3. Hereby, the air is ejected out in the room at high speed, while entering the air purifier 1 at low speed. This effect is enhanced the lower value that is selected for the threshold limit d, such as e.g. 0.3, 0.25, 0.1, 0.05 etc. An example of these proportions be- tween Am and Aoul may be studied in the Figures 1-10.

The air purifier 1 may also in some embodiments comprise an air outlet deflector 10, ar- ranged on the housing 2 in association with the air outlet 5, configured to direct the air flow of the air outlet 5 away from the housing 2 of the air purifier 1, see Figure 2.

The air outlet deflector 10 may form a top side 13 or table on top of the housing 2 as illus- trated in Figure 6. ln some embodiments, the air outlet deflector 10 forms an approximately perpendicular turn of the air flow of the air channel 7, thereby reducing noise emissions of the fan 8.

The air outlet deflector 10 may be adjustable in some embodiments, for adjusting direction of the ejected air flow.

The top side 13 of the housing 2 may be detachable as illustrated in Figure 7. lt hereby becomes easy to dismount the housing 2, also without tools in some embodiments, ascer- taining swift replacement of filters 9, and/ or performance of other service measures such as lubrication or exchange of the fan 8, etc.

Figure 8-9 illustrate the set of outlet filters 15, 17 may comprise at least one cylindrical coal filter 15, 17 arranged substantially vertical in the air channel 7 of the housing 2, releasably fastened with a respective fastener 19 at a lower end of the cylindrical coal filter 15, 17 towards a corresponding interface 18 wherein air flow from the fan 8 is received. Thereby 9 exchange of the cylindrical coal filters 15, 17 could be made within some seconds also with- out requirements of particular tools or skills, by twisting/ rotating the respective cylindrical coal filters 15, 17.

The terminology used in the description of the embodiments as illustrated in the accompa- nying drawings is not intended to be limiting of the described air purifier 1. Various changes, substitutions and/ or alterations may be made, without departing from invention embodi- ments as defined by the appended claims.

The different herein discussed embodiments of the air purifier 1 may with certain advantage be combined with each other, thereby achieving further advantages.

As used herein, the term "and/ or" comprises any and all combinations of one or more of the associated listed items. The term "or" as used herein, is to be interpreted as a mathematical OR, i.e., as an inclusive disjunction; not as a mathematical exclusive OR (XOR), unless ex- pressly stated othen/vise. ln addition, the singular forms "a", "an" and "the" are to be inter- preted as "at least one", thus also possibly comprising a plurality of entities of the same kind, unless expressly stated othen/vise. lt will be further understood that the terms "includes", "comprises", "including" and/ or "comprising", specifies the presence of stated features, ac- tions, integers, steps, operations, elements, and/ or components, but do not preclude the presence or addition of one or more other features, actions, integers, steps, operations, ele- ments, components, and/ or groups thereof. A single unit such as e.g. a filter 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.

Claims

1. An air purifier (1 ), comprising: a housing (2); an air inlet (3) arranged on a first side (4) of the housing (2); an air outlet (5) arranged on a second side (6) of the housing (2); an air channel (7) extending through the housing (2) from the air inlet (3) to the air outlet (5); a fan (8) arranged in the air channel (7) between the air inlet (3) and the air outlet (5); and at least one filter (9, 15, 17) configured to filter particles from the passing air, which filter (9, 15, 17) is arranged between the air inlet (3) and the air outlet (5); wherein a ratio between an area of the air outlet (5) and an area of the air inlet (3) is smaller than a threshold limit, which threshold limit is smaller than 0.

2. The air purifier (1) according to claim 1, comprising an air outlet deflector (10), ar- ranged on the housing (2) in association with the air outlet (5), configured to direct the air flow of the air outlet (5) away from the housing (2) of the air purifier (1).

3. The air purifier (1) according to any one of the preceding claims, wherein the air channel (7) comprises at least one approximately perpendicular turn between the air inlet (3) and the air outlet (5).

4. The air purifier (1) according to any one of the preceding claims, wherein the air channel (7) has a quadrilateral/ rectangular cross section.

5. The air purifier (1) according to any one of the preceding claims, wherein at least a part of the interior of the air channel (7) comprises sound absorbing elements (11).

6. The air purifier (1) according to any one of the preceding claims, wherein the air inlet (3) is arranged on a lateral side (12) of the housing (2) and the air outlet (5) is arranged on a top side (13) of the housing (2).

7. The air purifier (1) according to any one of the preceding claims, wherein the top side (13) of the housing (2) is detachable.

8. The air purifier (1) according to any one of the preceding claims, comprising a set of inlet filters (9) arranged in the air channel (7) between the air inlet (3) and the fan (8); and a set of outlet filters (15, 17) arranged in the air channel (7) between the fan (8) and the air outlet (5).

9. The air purifier (1) according to claim 8, wherein the set of outlet filters (15, 17) comprises at least one cylindrical coal filter (15, 17), arranged substantially vertical in the air channel (7) of the housing (2), releasably fastened with a fastener (19) at a lower end of the cylindrical coal filter (15, 17) towards an interface (18) wherein air flow from the fan (8) is received.

10. The air purifier (1) according to any one of the preceding claims, wherein the at least one filter (9, 15, 17) is configured to filter particles from the passing air without previous treatment of the air by ultraviolet light within the air purifier (1).