SE543984C2

SE543984C2 - Method for controlling a module for treating air, and related module

Info

Publication number: SE543984C2
Application number: SE1850902A
Authority: SE
Inventors: Anders Edström; Fredrik Edström; Mohamad Omar Mansour; Viktor Kjellberg
Original assignee: Sally R Ab
Priority date: 2018-07-13
Filing date: 2018-07-13
Publication date: 2021-10-19
Also published as: WO2020011669A1; SE1850902A1

Abstract

The present inventive concept relates to a module (100) for treating air, comprising first and second inlets (102, 128) and first and second outlets (106, 132), a treatment arrangement (110) configured to capture at least one impurity; and a catalyst (112). The module is configured to, in a cleaning mode, capture the at least one impurity; and in a regeneration mode, cease intake of a first flow of air via the first inlet and discharge of a second flow of air via the first outlet, increase a temperature of air within the module such that the at least one impurity captured by the treatment arrangement is released from the treatment arrangement, catalyze a reaction of the released at least one impurity via the catalyst, intake a third flow of air via the second inlet and discharge a fourth flow of air via the second outlet, wherein said intake of the third flow of air and discharge of the fourth flow of air are intermittent during the regeneration mode.

Description

METHOD FOR CONTROLLING A MODULE FOR TREATING AIR, AND RELATEDMODULE Technical field The inventive concept described herein generally relates to the field of airtreatment, and in particular to a method for controlling a module for treating air, anda related module.

Background According to recent estimations, 1 in 8 deaths are linked with air pollution. Airpollutions are present both outdoors and indoors, and since people today tend tospend a large amount of their time indoors, controlling the indoor environment istherefore of vital importance.

The field of indoor climate and indoor air quality has numerous aspects whichmay be divided into aspects relating to comfort and aspects relating to health issues.ln the context of this application, comfort climate refers to aspects of climate such astemperature, humidity, odour control, etc. Aspects of health climate on the otherhand are closely related to air pollution control. Examples of air pollutions mayinclude e.g. particulate matter, benzene, nitrogen dioxide, sulphur dioxide, carbonmonoxide, benzo(a)pyrene, radon, ozone, and volatile organic compounds (VOC)e.g. including hydrocarbons (HC), formaldehyde, alcohols, etc. ln an indoor environment, air pollution origins for example, from humans,furniture, cooking, etc. To control the indoor air pollution levels, the indoor air istherefore commonly let outside and ambient, or outside, air is let inside. Outdoor airmay however be for example too hot, cool, humid or polluted. Therefore, to achievea comfortable and healthy climate, the outside air led inside may have to be cooledor heated depending on the temperature, humidity may have to be added orremoved depending on the water content, outdoor air pollutions may have to beremoved, etc.

To control the temperature and to add and/or remove water from the outdoorair, heat pumps, or any other cooling machine, can be used. For example, theoutdoor air may be cooled to the desired dew point and then heated, in order toobtain a desired temperature and humidity level. However, for this to work the wholeyear around at a location having varying seasons, the size of the cooling machinemust unfortunately be chosen based on the demands on the expected hottest andmost humid day.

Furthermore, as mentioned above, if the outside air is too dry, a humidifiermust be used to control the humidity and/or if the outside air is polluted, air purifiersmust be used to control the air pollution inside. State of the art air purifiers commonlycomprise ionizers, HEPA filters, activated carbon beds, ultra violet light, thermaloxidation and catalytic oxidation. However, all these systems add to the energyrequirements and the investment bill.

Accordingly, controlling the indoor climate is energy intense, at least in partdue to the fact that the expected hottest, coolest and most polluted day of the yearsets the size for the constituents in the system. Moreover, these systems oftenoperate at a full capacity even if the building's occupancy is low. Hence bothinvestment- and operating costs for climate control devices tend to be high. ln order to alleviate some of these drawbacks, solutions have been proposedto reduce the energy requirements and/or the size of the system. For example, heatexchangers can be used to transfer energy between the indoor and the outdoor airwhen ventilating. This may reduce the need for heating and/or cooling. Also,measuring the indoor carbon dioxide and air pollution levels can lead to a reductionin the ventilation need. lf the flow is reduced, the energy needed for temperature,humidity and air pollution control can also be reduced. A system as mentioned abovecomprising a heat exchanger could be designed as follows: fresh air would usuallypass through a coarse filter that removes dust, leaves and other particles with largediameters. After that, it passes through a heat exchanger, where heat is exchangedbetween air supplied to the building (house) and return air coming back. ln this way,the desired supply air temperature is achieved with less energy expense.Consequently, the operation of cooling and/or heating elements, which in somecases are integrated into the system or built separately as chillers and radiators,could be reduced. For example, having an outdoor temperature of -5°C wouldrequire spending some amount of energy through the heaters to reach the supplytemperature of 20°C. By exchanging heat with the return air, which might be 24°C,the supply temperature could be elevated from -5 to 20°C with less energy fromthose heaters. Similarly, the return air would pass again through another course filterto protect the heat exchanger from dust, after which it is vented outside via theexhaust fan. ln order to increase the efficiency of the filtering capacity of the above-mentioned system, catalyst technologies may be applied. According to the prior art,there are volatile organic compound (VOC) concentrators. These concentratorsutilize a combination of adsorption and catalytic or thermal technologies toconcentrate the VOCs for destruction in catalytic or thermal oxidisers. Systems comprising concentrators of this kind may be useful for VOC concentrations that aretoo high for a cost-effective use of sacrificial systems and too low for a cost-effectiveuse of thermal or catalytic oxidisers. These systems are composed of eitheractivated carbon or zeolite as the adsorbing media to remove the VOCs.However, systems according to the prior art, such as systems comprisingVOC concentrators described above, are associated with numerous problems and/ordeficiencies. First, these systems are usually bulky, and are often too large to be fitinto and/or connected to commercial and residential air handling units (AHUs).Second, the prior art systems are associated with a relatively high cost. For example,a system comprising VOC concentrators with an efficiency of 5000 m3/h may costapproximately 15 000 - 30 000 Euros. For residential and commercial AHUs, thiscost is often considered unfeasible. Furthermore, the operation of systems of thiskind may include frequent refurbishments of the thermal oxidizer (depending on theVOC concentration to be concentrated) and a heating of the air to high temperaturelevels for the thermal oxidizer to catalyze the VOCs. Moreover, since the VOCconcentrator comprises zeolite or carbon, the system may experience a considerablepressure drop. Consequently, the flow rates of fans need to be increased, leading toan increase of the overall system energy consumption. Furthermore, the cleaning ofsupply and/or exhaust air, which is required for systems of this kind, requires arelatively large piping construction. Apart from an increasing cost associated withthis, the construction may increase the system complexity and volume, which isespecially problematic in case the space is limited.Hence, alternative solutions are of interest, which alleviate at least some of the above-mentioned problems, and are able to provide a more efficient system interms of operation, cost, space and/or complexity.

Summary of the invention lt is an object of the present inventive concept to mitigate, alleviate oreliminate one or more of the above-identified deficiencies in the art anddisadvantages singly or in combination.

According to a first aspect of the inventive concept, these and other objectsare achieved in full, or at least in part, by a module for treating air, the modulecomprising: a first inlet arranged for an intake of a first flow of air into the module; afirst outlet arranged for a discharge of a second flow of air from the module; atreatment arrangement configured to capture at least one impurity present in the firstflow of air; and a catalyst; wherein the module is configured to, in a cleaning mode,capture the at least one impurity present in the first flow of air via the treatmentarrangement by providing the intake of the first flow of air and the discharge of the second flow of air; and in a regeneration mode, cease the intake of the first flow ofair and the discharge of the second flow of air, increase a temperature of air withinthe module such that the at least one impurity captured by first treatmentarrangement is released from the treatment arrangement, and catalyze a reaction ofthe released at least one impurity via the catalyst. ln general, the present inventive concept is based on the realization that amodule for treating air may be operated in at least tvvo mutually exclusive modes; acleaning mode and a regeneration mode. ln the cleaning mode, impurities in airprovided to the module may be captured by a treatment arrangement, and in theregeneration mode the captured impurities may be released to undergo a reactionvia a catalyst. During the regeneration, a replenish air flow and discharge may beprovided in order to facilitate the regeneration of the treatment arrangement and inparticular in order to facilitate the reaction catalyzed via the catalyst.

The module may be configured to provide treated air to an enclosedenvironment such as a room or similar space in a building.

The term "capture" should in the context of the present disclosure beunderstood to comprise adsorbing and/or converting.

The catalyst may comprise at least one of a low temperature catalyst and ahigh temperature catalyst. The catalyst may be configured to catalyze the at leastone impurity at a temperature level of around 200 °C, such as between 150 °C and250 °C.

The catalyst may comprise or constitute (alternatively platinum coated) tindioxide (SnO2). For example, the weight percent of the platinum in platinum coatedtin dioxide may be in the range of 3-20 %. Particles of platinum-coated SnO2 may befabricated in a size-range that is comparable to the pigments of paint products thatcan be brushed or sprayed onto portion(s) of a catalyst support. For example, theparticles may have diameters in the order of 10 um or less The catalyst may comprise from 1-50 weight-%, based on the total weight ofthe catalyst, of a noble metal selected from the group consisting of platinum,palladium, gold, silver, and rhodium, which has been dispersed on from 50-99weight-%, based on the total weight of the catalyst, of a metal oxide whichpossesses more than one stable oxidation state including at least tin oxide. Thecatalyst may be particularly advantageous in case the noble metal is platinum andthe metal oxide is tin oxide.

The catalyst may comprise at least two precious metals with at least twodifferent metal-oxides (for example, tin oxide plus one or more promoters) in a layered matrix. Precious metals can together comprise about 0.1-15 weight-% of the Catalyst. The at least one promoter metal oxide may be chosen from metal oxidespecies from the transition series of the periodic table which are known to adsorbNOx species, namely, Fe203, NiO, Co203 and WO3. The composition of thepromoter oxide(s) can vary from about 1-15 weight-% of the total catalyst material.Specifically, about 10 weight-% of the catalyst may be Fe20, NiO, Co-O, combinedwith about 1.25 weight-% of the catalyst being platinum and ruthenium, with thebalance being tin oxide.

For example, the catalyst may comprise 70-99 weight-% of a metal oxidepossessing more than one oxidation state (e.g. tin oxide), 0.1-15 weight-% of at leasttwo precious metals of which one is Ru and the other is chosen from the groupconsisting of platinum (Pt), palladium (Pd), gold (Au), rhodium (Rh) and silver (Ag).The catalyst may further comprise 1-15 weight-% of at least one promoter selectedfrom the group consisting of Fe203, NiO, Co203 and WO3. lt will be appreciatedthat the catalyst as exemplified is associated with numerous advantages. Forexample, the relatively low light-off temperatures for CO and HC may enable an evenmore efficient catalytic conversion to C02 at a lower cost.

As yet another alternative, the catalyst may comprise 1-50 weight-% of anoble metal selected from the group consisiting of platinum (Pt), palladium (Pd), gold(Au), rhodium (Rh) and silver (Ag). The noble metal may have been dispersed onfrom about 50-99 weight-% of a metal oxide which possesses more than one stableoxidation state including at least tin oxide. The preparation of such a platinum-tinoxide-based catalyst may be accomplished by successive layering of the desiredcomponents, as follows: (1) a clean, dry substrate may be deaerated in a solutioncontaining tin (ll) 2-ethylhexanoate (SnEH, hereafter). The substrate is removed fromthe solution, and excess solution is removed from the substrate. Residual solutioncomponents are evaporated leaving an SnEH layer on the substrate which isthermally decomposed in air to tin oxide at 300°C. Several layers may be applied inthe same manner to achieve the desired loading of tin oxide. (2) lf desired, apromoter is added to the catalyst matrix in a similar fashion. For example, an ironoxide promoter may be added to an existing tin oxide-coated substrate by dearatingin an iron nitrate solution, removing excess solution, evaporating the solvent, andfinally thermally decomposing the nitrate to oxide. (3) Platinum may be added to thecoated substrate as above using an aqueous solution of tetraamine platinum (ll)dihydroxide or other platinum salt, with chloride-fee salts being preferred, and thenthermally decomposing the salt. lnstead of the thermal decomposition, a reductivedecomposition can be used. For example, the catalyst coated substrate is heated in an atmosphere containing a reducing gas such as carbon monoxide or hydrogen toinduce reduction of the platinum salt to platinum.

The active temperature of the catalyst may be -10°C-500°C. For example, forconversion of formaldehyde (CH20), the temperature of the catalyst may be 0°C-25°C, or even somewhat lower. For hydrocarbons (HC), desorption may take placefrom an initial temperature of the catalyst of about 35°C, and oxidation may beperformed at an active temperature of the catalyst at 80°C-120°C. The light-offtemperature may be about 150°C for hexane (C6H14) and about 220°C for methane(CH4). A complete oxidation may occur at an active temperature of the catalyst wellbelow the auto-ignition temperature of each hydrocarbon, e.g. 309°C for pentane(C5H12) and 537°C for methane. As yet another example, the temperature of thecatalyst for oxidation of ethanol (C2H5OH) may be about 30°C, and completeoxidization may be achieved at 125°C. Analogously, for propanol (C3H7OH), therespective temperatures of the catalyst may be 50°C and 120°C. For the oxidation ofcarbon monoxide (CO) and the reduction of nitrogen oxides (NOx), the activetemperature of the catalyst may be 200°C-500°C.

The catalyst may be configured to capture, adsorb and/or absorb, and toconvert, the at least one impurity. More specifically, the catalyst may capture, adsorband/or absorb the at least one impurity, and enable a reaction betvveen the at leastone impurity and an oxidizing agent, and desorb the oxidation products, therebyfreeing sites for subsequent adsorptions and/or absorptions and reactions.

The treatment arrangement may comprise a sorption media, such asactivated carbon and/or charcoal. Examples of such media include Chemsorb 3500,1425, 1000, 3620, NORIT R2030 C02.

The at least one impurity may comprise at least one of a volatile organiccompound (VOC), such as aldehydes, formaldehydes or amines, a particle, such asPl\/l2.s, PlVl1o, and/or PlVhoo, C02, CO, and ammonia. The sources of these impuritiesinclude humans (from respiration and perspiration, to clothing and cosmetics), aswell as building materials, equipment, food and consumer products, cleaningmaterials, office supplies or any other material which emit e.g. VOCs.

The module may comprise a main flow generating device configured to, in thecleaning mode, generate or facilitate the intake of the first flow of air via the first inletand the discharge of the second flow of air via the first outlet. The main flowgenerating device may be arranged outside of a main chamber as described below.The first inlet and the first outlet may be arranged on opposing sides of the module,allowing air to flow from the first inlet to the first outlet in a substantially straight line.

The module may further comprise a main chamber and a catalyst chamber,wherein the treatment arrangement is arranged in the main chamber and whereinthe catalyst is arranged in the catalyst chamber. Hereby, a circulating flow of air maybe provided between the treatment arrangement and the catalyst.

The main chamber and the catalyst chamber may be communicativelyconnected via a first and a second passage. Hereby, a circulating flow of air may beprovided between the treatment arrangement and the catalyst.

The module may comprise a heater arranged in the main chamber, whereinthe heater is configured to increase a temperature of air within the module.

The module may further comprise a flow generating device configured to, inthe regeneration mode, generate a circulation of air within the module from thecatalyst chamber to the main chamber and back to the catalyst chamber via the firstand second passages. Hereby, a circulating flow of air may be provided between thetreatment arrangement and the catalyst. The flow generating device may bearranged in the catalyst chamber. ln particular, the flow generating device may bearranged, with respect to the catalyst chamber, upstream of the catalyst. The flowgenerating device may be a fan.

The module may further comprise a second inlet arranged for an intake of athird flow of air into the module, and a second outlet arranged for a discharge of afourth flow of air from the module, wherein the module is further configured to, in theregeneration mode, intake the third flow of air and discharge the fourth flow of air.Hereby, regeneration of the treatment arrangement in the regeneration mode may befacilitated. lt has been realized that the reaction taking place via the catalyst, e.g.converting VOCs to C02 and H20, may be facilitated by replacing some of the airwithin the module with ambient air via the second inlet, and similarly by dischargingsome of the air within the module via the second outlet. Hereby, the conversion ofe.g. VOCs to C02 and H20 may continue.

The module may be further configured to, in the cleaning mode, cease theintake of the third flow of air and the discharge of the fourth flow of air. Hereby, themodule may be, at least intermittently, sealed off during regeneration. By the term"intermittently" it is to be understood that the second inlet and second outlet may attimes during regeneration be open to allow the third flow of air into the module and adischarge of the fourth flow of air from the module. By ceasing the intake of the thirdflow of air and the discharge of the fourth flow of air, the at least one impuritycaptured by the treatment arrangement may be released by increasing atemperature of air within the module. lncreasing the temperature of air within the module may be facilitated by limiting the amount of air entering and exiting themodule.

The second outlet may be arranged to direct the fourth flow of air to anambient space, such as an outdoor environment. The module may consequentlyprovide for that air being discharged from the module during or after the regenerationprocess is at least partly treated via the catalyst.

The module may further comprise a second flow generating deviceconfigured to, in the regeneration mode, facilitate the third flow of air. The secondflow generating device may be a fan. The second flow generating device may bearranged within the module, or outside of the module thus being an external part ofthe module. The second flow generating device may further facilitate the fourth flowof air.

The module may be further configured to, in the regeneration mode, intakethe third flow of air and discharge the fourth flow of air based on a predeterminedreplenish condition. The intake of the third flow of air and discharge of the fourth flowof air may be intermittent.

The replenish condition may comprise at least one of a predetermined timeinterval, a C02 level of air within the module, a level of the at least one impurity in airwithin the module, and a temperature of air within the module.

The predetermined time interval is to be understood as a predetermined timeinterval of the regeneration process. For example, the intake of the third flow of airand the discharge of the fourth flow of air, hereinafter referred to as a replenish airflow, may be provided at predetermined time intervals in the regeneration mode.

The C02 level may be determined by a C02 sensor arrangement arrangedwithin the module. The replenish condition may in particular pertain to an absoluteC02 value. ln one example, the C02 sensor arrangement comprises a first C02 sensorarranged in proximity of the second inlet, and a second C02 sensor arranged inproximity of the second outlet. The replenish condition may pertain to a difference between the C02 levels determined by the first and second C02 sensors respectively.

A given difference in readings may trigger the intake of the third flow of air and thedischarge of the fourth flow of air. For example, the C02 level determined by the firstC02 sensor being 450 ppm, and the C02 level determined by the second C02 sensorbeing 700 ppm (a difference of 250 ppm) may indicate that regeneration is inprocess, since C02 is a product of the regeneration process. A low, close to zero, orzero difference between the C02 levels determined by the first and second C02sensor may in contrast indicate that regeneration is completed. A low, close to zero, or zero difference between the C02 levels determined by the first and second C02sensor may also indicate that the catalyst has reached its end-of-life and should bereplenish or replaced. The person skilled in the art here realizes that the averagelifespan of a given catalyst may be taken into account when determining theappropriate action based on the sensor readings.

To further improve the determination of when to provide replenish air flow, atemperature of air within the module may be determined. The temperature may bedetermined by a thermal sensor arrangement arranged within the module. Thereplenish condition may in particular pertain to an absolute temperature value. ln one example, the thermal sensor arrangement comprises a first thermalsensor arranged upstream of the catalyst, and a second thermal sensor arrangeddownstream of the catalyst. The term "upstream" may here refer to upstream withinthe catalyst chamber, and similarly the term "downstream" may refer to downstreamwithin the catalyst chamber. The replenish condition may pertain to a temperaturedifference between the temperatures determined by the first and second thermalsensors respectively. A given difference in readings may trigger the intake of thethird flow of air and the discharge of the fourth flow of air. For example, thetemperature determined by the first thermal sensor being 150°C, and thetemperature determined by the second thermal sensor being 200°C (a difference of50°C) may indicate that regeneration is in process, if the reaction of the at least oneimpurity via the catalyst is an exothermic reaction. A low, close to zero, or zerodifference between the temperature determined by the first and second thermalsensor may in contrast indicate that regeneration is completed. Similarly to theabove, a low, close to zero, or zero difference between the temperature determinedby the first and second thermal sensor may also indicate that the catalyst hasreached its end-of-life and should be replenish or replaced. The person skilled in theart here realizes that the average lifespan of a given catalyst may be taken intoaccount when determining the appropriate action based on the sensor readings ln one example, the replenish condition comprise both a C02 level of airwithin the module and a temperature of air within the module. With reference to whathas been disclosed above, such an arrangement may at least theoretically encounterfour distinct scenarios, given an exothermic catalytic reaction: high/low C02difference and high/low temperature difference.

A scenario I, wherein the C02 difference is high and the temperaturedifference is low, is not likely to occur, since C02 generated during regeneration iscoming from catalytic activity, which means that the temperature difference shouldbe high.

A scenario ll, wherein the C02 difference is high and the temperaturedifference is high, may indicate that the regeneration process, i.e. the catalyst, isactive and that replenish air flow may be needed to facilitate the reaction via thecatalyst. Such a scenario may fulfil the replenish condition.

A scenario lll, wherein the C02 difference is low and the temperaturedifference is high, may indicate that the catalyst is active and that the regenerationprocess is close to finishing. Such a scenario may fulfil the replenish condition, but itmay not be necessary to provide additional replenish air flow.

A scenario IV, wherein the C02 difference is low and the temperaturedifference is low, may indicate that the regeneration process is completed. lt is envisioned that a volume and/or a flowrate of the third flow of air and thefourth flow of air may be based on the predetermined replenish condition.

Further scenarios are possible by taking a level of the at least one impurity inair within the module into account. Preferably, a level of the at least one impurity isdetermined at or in proximity of the second inlet, and/or at or in proximity of thesecond outlet. The module may comprise at least one sensor arranged andconfigured to determine the level of the at least one impurity at or in proximity of thesecond inlet, and/or at or in proximity of the second outlet. A given difference inreadings may trigger the intake of the third flow of air and the discharge of the fourthflow of air. For example, a VOC level determined by a sensor at the second inletbeing 200 ppb, and a VOC level determined by a sensor at the second outlet being700 ppb (a difference of 500 ppb) may indicate that regeneration is in process. lt isalso envisioned that a single sensor arranged at or in proximity of the second outletmay determine a level of the at least one impurity which may be compared to apredetermined impurity level.

The following four scenarios provide further detail regarding the level of the atleast one impurity.

A scenario V, wherein the VOC difference is high and the temperaturedifference is low, may indicate that the catalyst is inactive and replenish air flow maybe needed. A high VOC difference and low temperature difference may also indicatethat the catalyst has reached its end-of-life and should be replenish or replaced.

A scenario Vl, wherein the VOC difference is high and the temperaturedifference is high, may indicate that catalyst is active and that regeneration is inprocess. However, replenish air flow may still be needed, albeit at a lower flow rate than in scenario V.

A scenario VII, wherein the VOC difference is low and the temperature ishigh, may indicate that the catalyst is active and that the regeneration process isclose to finishing. Little to no replenish air flow may be needed.

A scenario VIII, wherein the VOC difference is low and the temperature islow, may indicate that the regeneration is completed. lt is envisioned that the module may utilize certain controllers taking intoaccount the parameters discussed in the present disclosure. Such controllers maycomprise P, I, D, Pl, PD, ID or PID controllers.

The module may be further configured to initiate the regeneration modebased on a predetermined regeneration initiation condition.

The regeneration initiation condition may comprise at least one of a level ofthe at least one impurity captured in the treatment arrangement, a time-of-day, a timeof operating the module in the cleaning mode, a time of operating the module in theregeneration mode, a time elapsed since last initiation of the regeneration mode, alevel of the at least one impurity in the first flow of air, a level of the at least oneimpurity in the second flow of air, and a desired level of the at least one impurity inthe second flow of air.

The regeneration initiation condition will in the following sections be describedin further detail.

There are various ways to determine whether to initiate regeneration, e.g.fulfil the regeneration initiation condition. Ultimately, it may be of interest to determinean efficiency of the treatment arrangement, i.e. if the treatment arrangement iscapturing at least some of the at least one impurity such that the discharge of thesecond flow of air via the first outlet has a concentration of the at least one impuritybelow a predetermined level. The efficiency of the treatment arrangement may beestimated by determining the level of the at least one impurity captured in thetreatment arrangement.

The level of the at least one impurity captured in the treatment arrangementmay in turn be proportional to a time of operating the module in the cleaning modeand/or to a date the module is operating in the cleaning mode, hence theregeneration initiation condition may comprise a time of operating the module in thecleaning mode and/or a date the module is operating in the cleaning mode. Forexample, the regeneration initiation condition may be fulfilled if the module has beenoperating in the cleaning mode for a predetermined period of time and/or if apredetermined period of time has elapsed since last initiation (and/or termination) ofregeneration mode. lt may be clarified that the date of operating the module in thecleaning mode may have an effect on an occupancy within the enclosed environment to which the module may provide air. Similarly, the time-of-day mayhave an effect on the occupancy within the enclosed environment. The date ofoperating the module in the cleaning mode and/or the time-of-day may affect a levelof the at least one impurity in the first flow of air via the first inlet, hence if the level ofthe at least one impurity is high, the treatment arrangement may need regeneration(e.g. may become saturated) earlier compared to a lower level of the at least oneimpurity in the first flow of air. Further, the date of operating the module in thecleaning mode and/or the time-of-day may in contrast provide an indication that theoccupancy of the enclosed environment is low, and hence that the first flow of air hasa low or zero content of the at least one impurity. ln this case it may be preferable toinitiate regeneration, since the first flow of air may be provided to the enclosedenvironment via e.g. a bypass path configured to bypass the module without passingthe treatment arrangement.

The level of the at least one impurity in the second flow of air may trigger theinitiation of the regeneration. ln particular, if the level of the at least one impurity inthe second flow of air is above a desired level of the at least one impurity in thesecond flow of air, the regeneration initiation condition may be fulfilled.

The regeneration initiation condition may be fulfilled upon an efficiency of thetreatment arrangement dropping below a predetermined efficiency level. Theefficiency level may be defined as one minus the ratio of the level of the at least oneimpurity in the first flow of air and the level of the at least one impurity in the secondflow of air.

The module may comprise at least one sensor arranged and configured todetermine the level of the at least one impurity in the first flow of air and/or thesecond flow of air.

With reference to the occupancy level of the enclosed environment, themodule may be configured to receive data pertaining to the occupancy level of theenclosed environment from at least one external occupancy level sensor arranged inthe enclosed environment. The module may also be configured to receive datapertaining to an air quality and/or a level of the at least one impurity in air within theenclosed environment. One way of determining the occupancy level is to arrange atemperature sensor and/or C02 sensor in conjunction with air being supplied to theenclosed environment (e.g. air being discharged from air treatment unit), andanother temperature sensor and/or C02 sensor in conjunction with air beingdischarged from the enclosed environment (e.g. air being supplied to air treatmentunit from enclosed environment). A difference in C02 level or temperature level between air entering and exiting the enclosed chamber may then be determined.

Further by dividing the difference in C02 level or temperature level by an averageamount of C02 or heat emission of one person, an occupancy level of the enclosedenvironment may be determined. The regeneration initiation condition may comprisean air quality and/or a level of the at least one impurity in air within the enclosedenvironment.

The module may be further configured to terminate the regeneration modebased on a predetermined regeneration termination condition.

The regeneration termination condition may comprise at least one of a levelof the at least one impurity captured in the treatment arrangement, a time-of-day, atime of operating the module in the cleaning mode, a time elapsed since initiation ofthe regeneration mode, a time of operating the module in the regeneration mode, alevel of the at least one impurity of air within the module, a temperature of air withinthe module, and a level of the at least one impurity of air within an enclosedenvironment to which the module is providing air.

The regeneration termination condition may be similar or identical to theregeneration initiation condition and/or the replenish condition at least in part. lnparticular, the scenarios l-Vlll described earlier in the disclosure may be of relevancefor the regeneration termination condition. Further, it is envisioned that theregeneration process must not necessarily continue until the treatment arrangementis fully regenerated. ln contrast, it may be preferable to regenerate the treatmentarrangement partly, i.e. the regeneration mode may be active until a level of the atleast one impurity in air at or in proximity of the second outlet is at or below apredetermined threshold.

For the sake of brevity, the regeneration termination condition is not furtherdiscussed; reference is made to the sections discussing the regeneration initiationcondition and the replenish air condition.

The module may be further configured to terminate the regeneration modeand then initiate the cleaning mode based on the predetermined regenerationtermination condition. lt is further envisioned that a pre-filter may be arranged upstream of thetreatment arrangement of the module. The pre-filter may be configured to filter,capture, collect or remove high molecularweight (HMW) impurities, such as ethylacetate, toluene, cyclohexane etc. Such impurities may be defined as impurities witha molecular Weight over 80 g/mol. The pre-filter may thus decrease, or fully prevent,the amount of HMW impurities being captured by the treatment arrangement of themodule. This is advantageous since HMW impurities may be difficult to release fromthe treatment arrangement, thus diminishing the effectivity and/or lifespan of the treatment arrangement. The pre-filter may be integral to the module, however it isalso envisioned that the pre-filter may be arranged in the system described inconjunction with FIG. 3, external to the module.

According to a second aspect of the inventive concept, these and otherobjects are achieved in full, or at least in part, by a method for controlling a modulefor treating air, the module comprising a first inlet arranged for an intake of a first flowof air into the module; a first outlet arranged for a discharge of a second flow of airfrom the module; a treatment arrangement configured to capture at least oneimpurity present in the first flow of air; and a catalyst; wherein the method comprisesthe steps of: initiating one of a cleaning mode and a regeneration mode, wherein thecleaning mode comprises the steps of: providing the intake of the first flow of air andthe discharge of the second flow of air; capturing the at least one impurity present inthe first flow of air via the treatment arrangement; and wherein the regenerationmode comprises the steps of: ceasing the intake of the first flow of air and thedischarge of the second flow of air; increasing a temperature of air within the modulesuch that the at least one impurity captured by first treatment arrangement isreleased from the treatment arrangement; and catalyzing a reaction of the releasedat least one impurity via the catalyst.

The cleaning mode may further comprise capturing at least one highmolecular weight impurity via a pre-filter.

A feature described in relation to one aspect may also be incorporated inother aspects, and the advantage of the feature is applicable to all aspects in which itis incorporated.

Other objectives, features and advantages of the present inventive conceptwill appear from the following detailed disclosure, from the attached claims as well asfrom the drawings.

Generally, all terms used in the claims are to be interpreted according to theirordinary meaning in the technical field, unless explicitly defined othenNise herein.Further, the use of terms "first", "second", and "third", and the like, herein do notdenote any order, quantity, or importance, but rather are used to distinguish oneelement from another. All references to "a/an/the [element, device, component,means, step, etc]" are to be interpreted openly as referring to at least one instance ofsaid element, device, component, means, step, etc., unless explicitly statedotherwise. The steps of any method disclosed herein do not have to be performed inthe exact order disclosed, unless explicitly stated.

Brief description of the drawings The above, as well as additional objects, features and advantages of thepresent inventive concept, will be better understood through the following illustrativeand non-limiting detailed description of different embodiments of the presentinventive concept, with reference to the appended drawings, wherein: FIG. 1 schematically illustrates a module according to the inventive concept; FIG. 2a schematically illustrates a module operating in a cleaning mode; FIG. 2b schematically illustrates a module operating in a regeneration mode; FIG. 3 schematically illustrates a system for treating air comprising themodule according to the inventive concept; FIG. 4 is a flowchart diagram of a method for controlling a module for treatingair.

The figures are not necessarily to scale, and generally only show parts thatare necessary in order to elucidate the inventive concept, wherein other parts maybe omitted or merely suggested.

Detailed description FIG. 1 illustrates a module 100 for treating air according to the inventiveconcept. The module 100 comprises a first inlet 102 arranged for an intake of a firstflow of air 104 into the module 100, a first outlet 106 arranged for a discharge of asecond flow of air 108 from the module 100, a treatment arrangement 110configured to capture at least one impurity present in the first flow of air 104, and acatalyst 112. The module here also further comprises a heater 114 configured toincrease a temperature of air within the module 100, and a main flow generatingdevice 116 configured to, in the cleaning mode, generate or facilitate the intake ofthe first flow of air 104 via the first inlet 102 and the discharge of the second flow ofair 108 via the first outlet 106.

The module is divided into a main chamber 120 and a catalyst chamber 122.A flow generating device 118 is configured to, in the regeneration mode, generate acirculation of air within the module 100 from the catalyst chamber 122 to the mainchamber 120 and back to the catalyst chamber 122 via a first passage 124 and asecond passage 126. The first passage 124 and the second passage 126 maycomprise an opening, a valve, or the like. ln particular, the flow generating device118 may be configured to, in the regeneration mode generate a circulation of airwithin the module 100 from the treatment arrangement 110 to the catalyst 112 viathe first passage 124 and the second passage 126.

The module here further comprises a second inlet 128 arranged for an intakeof a third flow of air 130 into the module 100, and a second outlet 132 arranged for a discharge of a fourth flow of air 134 from the module 100. The module 100 may thusbe further configured to, in the regeneration mode, intake the third flow of air 130 anddischarge the fourth flow of air 134. Hereby, regeneration of the treatmentarrangement 110 in the regeneration mode may be facilitated. lt should be noted that the first flow of air 104, the second flow of air 108, thethird flow of air 130 and the fourth flow of air 134, although all being depicted in thesame figure, are not necessarily all present at the same time. For example, in thecleaning mode, only the first and second flow of air 104, 108 may be present, and inthe regeneration mode, only the third and fourth flow of air 130, 134 may be present.

Sill referring to FIG. 1, a first and a second air path 136, 138 may beconnected to the module 100 for providing air from various sources to the module100. For example, the first air path 136 may provide ambient air to the module, andthe second air path 138 may provide exhaust air to the module 100 from an airtreatment unit connected to the module 100. The first and second air path 136, 138may be controlled via respective valves (not shown).

The second flow of air 108 discharged from the module 100 may be directedto an enclosed environment such as a room in a building either directly or via e.g. anair treatment unit. An overview of such a system is disclosed in conjunction with FIG.3.

Referring now to FIG. 2a, a module 200a operating in a cleaning mode isillustrated. For the sake of brevity, some of the features already discussed inconjunction with FIG. 1 will not be repeated in the following sections.

The first flow of air 204 and the second flow of air 208 is here provided. Themodule 200a may control the first inlet 202 and the first outlet 206, e.g. viarespective valves, in order to provide the first flow of air 204 and the second flow ofair 208. Air entering the module 200a via the first inlet 202 is directed via thetreatment arrangement 210, thus allowing at least one impurity present in the firstflow of air 204 to be captured by the treatment arrangement 210. ln the cleaningmode, the first and second passage 224, 226 may be closed, thus restricting airwithin the module 200a to the main chamber 220. ln other words, air within themodule 200a may be prevented from entering the catalyst chamber 222.

Referring now to FIG. 2b, a module 200b operating in a regeneration mode isillustrated. For the sake of brevity, some of the features already discussed inconjunction with FIG. 1 will not be repeated in the following sections. The first flow ofair and the second flow of air provided via the first inlet and outlet 202, 206respectively are ceased. The module 200b may cease the first flow of air and thesecond flow of air via e.g. respective valves. A flow generating device 218 may be controlled to generate a circulating flow of air 228 from the catalyst Chamber 222 tothe main chamber 220 via the second passage 226, and back to the catalystchamber 222 via the first passage 224. ln particular, the circulating flow 228 maypass the treatment arrangement 210. Further, a heater 214 may be controlled toincrease a temperature of air within the module 200b. The heater may be configuredto increase the temperature of air within the module to at least 150 °C. The heatermay be configured to increase the temperature of air within the module to between150 °C and 400 °C. Hereby, impurities captured by the treatment arrangement 210may be released into air within the module 200b, and the circulating flow 228 maythen bring the impurities into contact with the catalyst 212, thus converting theimpurities via the catalyst 212 into products which may be discharged from themodule 200b via the second outlet 232.

The module may be further configured to, in the regeneration mode, intakethe third flow of air 230 via the second inlet 228 and discharge the fourth flow of air234 via the second outlet 232. The intake of the third flow of air and discharge of thefourth flow of air may be intermittent.

FIG. 3 schematically illustrates an example of a system 301 for treating aircomprising the module 302 according to the inventive concept. The module 302 herebeing configured to be used in conjunction with an air treatment unit 305 comprisingan inlet arrangement 307 for an intake of a first flow of air and an outlet arrangement309 for a discharge of exhaust air from the air treatment unit 305.

The module here comprises a first module inlet 311 for an intake of ambientair 320, and a second module inlet 313 configured to be connectable to the outletarrangement 309 of the air treatment unit 305 and arranged for an intake of theexhaust air from the air treatment unit 305. The module further comprises a firstmodule outlet 315 configured to be connectable to the inlet arrangement 307 of theair treatment unit 305. lt is to be understood that the module 302 may comprisefurther inlets and/or outlets, however for the sake of clarity such inlets and/or outletsare not illustrated in the figure.

The air treatment unit 305 may be connected to an enclosed environment317, and may be suitable for managing the condition, or quality, of air in theenclosed environment 317. By enclosed environment may in some embodiments beunderstood as an environment such as a room or similar space in a building. Otherexamples of enclosed environment include compartment of vehicles. The airtreatment unit 305 may comprise means for inducing, or creating, a flow of air or acirculation of air. Such means include for example fans or pumps of which manytypes are available, since these types of components are well known in the art they will however not be described in further detail. The ambient air 320 may be airpresent outside of e.g. a room or building, or more specifically air present outside ofthe closed environment 317. lf the air treatment unit 305 is equipped with means for inducing or creating aflow of air or a circulation of air, it may be advantageous to arrange the module 302such that the second inlet 313 of the module 302 is receiving exhaust air from the airtreatment unit 305 (as illustrated), i.e. downstream of the air treatment unit 305. Suchan arrangement may work with, rather than against, the pressure or flow created bythe air treatment unit 305. However, it may also be possible to arrange the module302 such that the second inlet 313 receive air from the enclosed environment 317before the air has reached the air treatment unit 305, i.e. arranging the second inlet313 upstream of the air treatment unit 305. ln the illustrated example, the various inlets and outlets described in theprevious sections are connected via paths configured to convey air. Examples ofsuch paths include ducts and pipes providing fluid connection between thecomponents of the system according to the present inventive concept. lt should benoted that the illustrated paths are merely a schematic representation of oneexample of the inventive concept.

A bypass path 319 is arranged to bypass the module 302, and the bypasspath 319 is configured to convey ambient air 320 into the air treatment unit 305 viathe inlet arrangement 307. The bypass path 319 may be utilized to convey ambientair 320 into the air treatment unit 305 in case the ambient air 320 does not need tobe treated in the module 302.

As can be seen, an outflow provided by the module 302 via the first outlet315 is directed to the bypass path 319 via an outflow path 321, and the outflow maythen enter the air treatment unit 305 via the inlet arrangement 307. Further, exhaustair is provided to the module from the outlet arrangement 309 via an exhaust air path323. Other arrangements of paths are possible within the scope of the presentinventive concept.

The present inventive concept provides for several possibilities in terms of airto be provided to the air treatment unit 305. ln general, the module 302 may beconfigured to provide an outflow from the module 302 via the first outlet 315 bycontrolling a first flowrate of the ambient air 320 via the first inlet 311 and a secondflowrate of the exhaust air via the second inlet 313 based on at least one parameterassociated with at least one of the ambient air 320 and the exhaust air. ln particular,any of the first flowrate of the ambient air 320 via the first inlet 311 and the secondflowrate of the exhaust air via the second inlet 313 may be zero. ln general, the system 301 and the module 302 may utilize a number ofalgorithms in order to determine, based on at least one parameter associated withthe exhaust air and the ambient air 320, a set of flowrates (e.g. ambient air flowratevia first inlet and/or bypass path, outflow flowrate, exhaust air flowrate) whichachieves a set air quality (e.g. a desired value pertaining to the at least oneparameter) with the least energy expensed.

For example, exhaust air having a low concentration of VOCs and a lowtemperature relative respective given desired values may require less energy tobring to the respective given desired values compared to ambient air having a highconcentration of VOCs but a close to ideal temperature relative the same respectivegiven desired values.

The module 302 may further be configured to control an ambient air flowratefrom the bypass path 319 and an outflow flowrate from the first outlet 315 of themodule 302 based on the at least one parameter associated with at least one of theambient air 320 and the outflow from the first outlet 315. ln particular, any of theambient air flowrate from the bypass path 319 and the outflow flowrate from the firstoutlet 305 may be zero.

The system 301 may comprise at least one sensor. Here, three sensors 325,327, 329 are illustrated. The system may advantageously comprise one or moresensors within the module 302, and it is to be understood that the illustrated sensorsare merely examples of sensors and their respective locations. The sensor 325 maye.g. be configured to determine parameter data pertaining to the at least oneparameter associated with exhaust air discharged by the air treatment unit 305 viathe outlet arrangement 309. The sensor 327 may e.g. be configured to determineparameter data pertaining to the at least one parameter associated with outflowprovided by the module 302 via the first outlet 315. The sensor 329 may e.g. beconfigured to determine parameter data pertaining to the at least one parameterassociated with the ambient air 320.

A method for controlling a module for treating air according to the inventiveconcept will now be described with reference to FIG. 4. For clarity and simplicity, themethod will be described in terms of 'steps'. lt is emphasized that steps are notnecessarily processes that are delimited in time or separate from each other, andmore than one "step" may be performed at the same time in a parallel fashion.

The module comprises a first inlet arranged for an intake of a first flow of airinto the module; a first outlet arranged for a discharge of a second flow of air fromthe module; a treatment arrangement configured to capture at least one impuritypresent in the first flow of air; and a catalyst; and the method comprises a step 480 of initiating one of a cleaning mode and a regeneration mode, wherein the cleaningmode comprises the steps of: a step 482 of providing the intake of the first flow of airand the discharge of the second flow of air; a step 484 of capturing the at least oneimpurity present in the first flow of air via the treatment arrangement; and wherein theregeneration mode comprises the steps of: a step 486 of ceasing the intake of thefirst flow of air and the discharge of the second flow of air; a step 488 of increasing atemperature of air within the module such that the at least one impurity captured byfirst treatment arrangement is released from the treatment arrangement; and a step490 of catalyzing a reaction of the released at least one impurity via the catalyst.

The inventive concept has mainly been described above with reference to afew embodiments. However, as is readily appreciated by a person skilled in the art,other embodiments than the ones disclosed above are equally possible within thescope of the inventive concept, as defined by the appended patent claims.

Claims

1. 1. A module (100) for treating air, the module (100) comprising: a first inlet (102) arranged for an intake of a first flow of air (104) into themodule (100); a first outlet (106) arranged for a discharge of a second flow of air (108)from the module (100); a second inlet (128) arranged for an intake of a third flow of air (130) intothe module (100); a second outlet (132) arranged for a discharge of a fourth flow of air (134)from the module (100); a treatment arrangement (110) configured to capture at least one impuritypresent in the first flow of air (104); a heater (114) configured to increase a temperature of air within themodule (100); and a catalyst (112); wherein the module (100) is configured to, in a cleaning mode, capture the at least one impurity present in the firstflow of air (104) via the treatment arrangement (110) by providing the intake of thefirst flow of air (104) and the discharge of the second flow of air (108); and in a regeneration mode, cease the intake of the first flow of air (104) andthe discharge of the second flow of air (108), increase a temperature of air within themodule (100) such that the at least one impurity captured by íèsﬂaæflejgåggçggtreatmentarrangement (110) is released from the treatment arrangement (110), catalyze areaction of the released at least one impurity via the catalyst (112), intake the thirdflow of air (130) and discharge the fourth flow of air (134), än said intake of the third flow of air (130) anddischarge of the fourth flow of air (134) are intermittent during the regeneration mode.

2. The module (100) according to claim 1, further comprising a mainchamber (120) and a catalyst chamber (122), wherein the treatment arrangement(110) is arranged in the main chamber (120) and wherein the catalyst (122) isarranged in the catalyst chamber.

3. The module (100) according to claim 2, wherein the main Chamber (120)and the Catalyst chamber (122) are communicatively connected via a first and asecond passage (124, 126).

4. The module (100) according to claim 3, further comprising a flowgenerating deviceg (118) configured to, in the regeneration mode, generate acirculation of air within the module (100) from the catalyst chamber (122) to the mainchamber (120) and back to the catalyst chamber (122) via the first and secondpassages (124, 126).

5. The module (100) according to claim 1, further configured to, in thecleaning mode, cease the intake of the third flow of air (130) and the discharge of thefourth flow of air (134).

6. The module (100) according to any one of the preceding claims, furthercomprising a :šflow generating device§§ configured to, in the regenerationmode, facilitate the third flow of air (130).

7. The module (100) according to any one of the preceding claims, furtherconfigured to, in the regeneration mode, intake the third flow of air (130) anddischarge the fourth flow of air (134) based on a predetermined replenish condition.

8. The module (100) according to claim 7, wherein the replenish conditioncomprises at least one of a predetermined time interval, a C02 level of air within themodule (100), a level of the at least one impurity in air within the module (100), and atemperature of air within the module (100).

9. The module (100) according to claim 7 or 8, wherein a volume and/or aflowrate of the third flow of air (130) and the fourth flow of air (134) is based on thepredetermined replenish condition.

10. The module (100) according to any one of the preceding claims, furtherconfigured to initiate the regeneration mode based on a predetermined regenerationinitiation condition.

11. The module (100) according to claim 10, wherein the regenerationinitiation condition comprises at least one of a level of the at least one impuritycaptured in the treatment arrangement (110), a time-of-day, a time of operating themodule (100) in the cleaning mode, a time of operating the module (100) in theregeneration mode, a time elapsed since last initiation of the regeneration mode, alevel of the at least one impurity in the first flow of air (104), a level of the at least oneimpurity in the second flow of air (108), and a desired level of the at least oneimpurity in the second flow of air (108).

12. The module (100) according to any one of the preceding claims, furtherconfigured to terminate the regeneration mode based on a predetermined regeneration termination condition.

13. The module (100) according to claim 12, wherein the regenerationtermination condition comprises at least one of, a level of the at least one impuritycaptured in the treatment arrangement (110), a time-of-day, a time of operating themodule (100) in the cleaning mode, a time elapsed since initiation of theregeneration mode, a level of the at least one impurity of air within the module (110),a temperature of air within the module (110).

14. The module (100) according to claim 12 or 13, further configured toterminate the regeneration mode and then initiate the cleaning mode based on the predetermined regeneration termination condition.

15. The module (100) according to any one of the preceding claims, whereinthe catalyst (112) comprises tin dioxide.

16. A method for controlling a module (100) for treating air, the module (110) comprising a first inlet (102) arranged for an intake of a first flow of air (104) into themodule (100); a first outlet (106) arranged for a discharge of a second flow of air (108)from the module (100); a second inlet (128) arranged for an intake of a third flow of air (130) intothe module (100); a second outlet (132) arranged for a discharge of a fourth flow of air (134)from the module (100); a treatment arrangement (110) configured to capture at least one impuritypresent in the first flow of air (104); a heater (114) configured to increase a temperature of air within themodule (100); and a catalyst (112); wherein the method comprises the steps of: switching between a cleaning mode and a regeneration mode, whereinthe cleaning mode comprises the steps of: providing the intake of the first flow of air (104) and the discharge of thesecond flow of air (108); capturing the at least one impurity present in the first flow of air (104) viathe treatment arrangement (110); and wherein the regeneration mode comprises the steps of: ceasing the intake of the first flow of air (104) and the discharge of thesecond flow of air (108); increasing a temperature of air within the module (100) such that the at least one impurity captured by treatment arrangement (110) is released from the treatment arrangement (110);catalyzing a reaction of the released at least one impurity via the catalyst(112);providing the intake of the third flow of air (130); anddischarging the fourth flow of air (134); said intake of the third flow of air (130) and discharge of the fourth flow of air (134) are intermittent during the regenerationmode.