US20210270477A1

US20210270477A1 - Air purifier

Info

Publication number: US20210270477A1
Application number: US17/255,090
Authority: US
Inventors: Christian Neese; Benjamin Amshoff
Original assignee: Miele und Cie KG
Current assignee: Miele und Cie KG
Priority date: 2018-07-12
Filing date: 2019-06-12
Publication date: 2021-09-02
Also published as: CN112368516A; EP3821175B1; EP3821175A1; WO2020011468A1

Abstract

An air purifier includes a housing (1), an intake built into the housing (1) which is designed for the intake of air into the housing (1), an exhaust built into the housing (1) which is designed for the venting of air out of the housing (1), a blower (2) disposed in the housing for generating an air stream which flows from the intake to the exhaust, at least one filter (3) which is designed to purify the air flowing from the intake to the exhaust, and a bioreactor (4) which is disposed on and/or in the housing (1) such that the air stream flows through it, and which contains at least one life form (5) which is designed to at least partially convert CO2 contained in the air stream into O2 by means of photosynthesis.

Description

TECHNICAL FIELD

The invention relates to an air purifier. In particular, the invention relates to an air purifier which is designed to purify air in the interior space of a building such as a living room, an office, a conference room, or the like.

BACKGROUND

An air purifier is known from CN105605687A, featuring a housing, an intake disposed in the housing which is designed to admit air into the housing, an exhaust disposed in the housing which is designed to dispel air out of the housing, a blower disposed in the housing to generate an air stream which flows from the intake to the exhaust, and at least one filter which is designed to purify the air stream flowing from the intake to the exhaust. Furthermore, the air purifier features a humidifier, a dehumidifier, a heat exchanger, a control unit, and a sensor unit with a moisture sensor and a temperature sensor. With this air purifier the temperature and humidity can be adjusted in such a way that a person in an interior space feels comfortable. Additionally, contaminants such as dust, bacteria, and toxic gases are filtered out of the air by means of the filter.
Along with humidity and temperature, however, there is an additional factor which contributes to a person's perception of comfort in an interior space. When people spend a longer period of time in a closed room, this leads to an increase in the CO₂content of the room due to human respiration. The increasing CO₂content is responsible for people beginning to feel tired and lacking in concentration, which can also lead to health issues. In such a case, the person has a tendency to open a window in order to create ventilation. This results in outside air flowing in, which has a lower CO₂content, but this outside air also contains many of the described contaminants. Thus the CO₂content in the interior space is reduced, but conversely the amount of contaminants in the interior air is increased.

SUMMARY

Thus the invention addresses the problem of providing an air purifier which is suited to regulate—in particular to reduce—the CO₂content in an interior space.
Along with the regulation—in particular the reduction—of CO₂content in the interior space, the invention favorably saves energy, as the warmth or coolness of the interior space is not sacrificed during ventilation with outside air. It is not necessary to open the window to admit outside air into the interior space in order to reduce the CO₂content in the interior air.
A bioreactor is provided in accordance with the invention, which is disposed on and/or in the housing such that the air stream flowing through the air purifier passes through it, and which contains at least one life form which is capable of converting the CO₂contained in the air stream at least partially into O₂by means of photosynthesis.
The air purifier according to the invention is thus capable of regulating the CO₂content of the interior air such that a person feels comfortable in an interior space. Also, the CO₂contained in the interior air is not passed to the outside air, and thus no line needs to be run to the outside. Filtering of CO₂out of the interior air by means of the air purifier according to the invention therefore requires no connection to the outside air such as, for example, an outlet from the interior space. Thus a perfect interior climate is provided for a person in the interior space, wherein in particular the O₂content in the interior space is increased and the CO₂content of the interior air is reduced. Thus no hazardous and/or toxic substances are used, nor are such substances generated. Additionally, the CO₂is also not stored in a storage medium, from which it must be subsequently released.
The at least one filter is preferably suitable for filtering airborne contaminants from the air flowing through it. Airborne contaminants are generally coarse dust, fine dust, viruses, bacteria, microbes, odors, pollen, smoke, and/or compounds, in particular organic compounds, as well as volatile organic compounds (VOCs), which can be harmful to human health. The at least one filter can be an electrostatic filter and/or an air scrubber. Preferably the at least one filter is a filter with a solid filter medium. For example, the at least one filter is a three-filter combination made of a prefilter and high-performance particulate filter or HEPA filter or high-performance HEPA filter and activated charcoal filter.
The intake built into the housing, the exhaust built into the housing, the blower built into the housing, the at least one filter, and the bioreactor are disposed such that the air stream flowing from the intake to the exhaust is directed through the at least one filter and the bioreactor. Preferably the aforementioned parts are disposed such that the air stream flows first through the at least one filter and then through the bioreactor and then through the exhaust. The bioreactor thereby features an intake for admitting an air stream and an exhaust for dispensing air from the bioreactor. The bioreactor exhibits at least one life form which is designed to at least partially convert the CO₂contained in the air stream into O₂by means of photosynthesis. Thus the photosynthesizing life form can be prevented from coming into contact with coarse dust, fine dust, viruses, bacteria, microbes, odors, pollen, smoke, and/or organic compounds, and/or the aforementioned airborne contaminants to be filtered can be prevented from accumulating in the bioreactor, since the air flowing through the bioreactor has already been cleansed of them by the at least one filter.
The photosynthesis can be conducted by plants, algae and/or bacteria as life forms which are designed to at least partially convert the CO₂contained in the air stream into O₂. It is therefore a case of oxygenic photosynthesis. In oxygenic photosynthesis, energy-rich organic compounds such as carbohydrates, in particular glucose, are generated from energy-poor inorganic substances such as CO₂and water with the help of one or more light-absorbing pigments such as, for example, chlorophyll, whereby O₂is created. Plants and algae need light for photosynthesis. If no light is present, a respiration process begins which damages the plants and algae.
The basic idea of the bioreactor is therefore the reduction of CO₂via the activity of the photosynthesizing life form, which converts CO₂at least partially to O₂by means of photosynthesis. The bioreactor preferably features a container which contains water and the life form. If air is now directed into the container, the at least one life form uses photosynthesis to convert the CO₂in the air into energy-rich organic compounds, which the at least one life form uses for cell growth. The air—with reduced CO₂—then subsequently exits the bioreactor, and thus exits the air purifier. The air purifier may feature its own light source, although this is not required. Preferably it features a lighting unit, as conditions for permanent photosynthesis can thereby be achieved.
The bioreactor is preferably disposed outside the housing. It is preferably disposed on the housing, correlating with the intended operating position of the air purifier. For example, the housing and the bioreactor can be designed such that the bioreactor can be attached to the housing. It is thus easy to replace. If required, the bioreactor and/or the housing can feature one or more securing elements, which can additionally secure an attached bioreactor on the housing. Thus the bioreactor can be prevented from lifting from and/or detaching from the housing, for example if the air purifier is knocked over.
The at least one photosynthesizing life form is preferably selected such that it exhibits stable growth at low CO₂partial pressures.
In a preferred embodiment, the at least one photosynthesizing life form is at least one alga. An alga is a plant-like life form. The term “alga” is to be understood as a eukaryotic life form which lives in water and performs photosynthesis. Due to their size, algae can be divided into two groups. Microscopically small types are designated as microalgae; in particular including unicellular and small multicellular forms. A microalga cannot be seen with the unaided eye. A macroalga or large alga, in contrast, is multicellular and can be seen with the unaided eye. Advantages of the use of algae in comparison to plants are the absence of debris such as roots, dead leaves, blossoms, and the like, and less water consumption.
Traditionally, cyanobacteria are designated as “blue algae”. The designation “blue algae” is used for all cyanobacteria—also for those which do not contain phycocyanin as a photosynthesis pigment and are not colored blue-green. Previously they were considered phycophyta—that is, algae—and were categorized as the class cyanophyceae. In contrast to algae, cyanobacteria do not have a true cell nucleus, however, and are therefore prokaryotes. As prokaryotes, they are not related to the eukaryotic life forms known as “algae,” and strictly speaking are not algae at all. In the context of the invention, however, the term “algae” also includes cyanobacteria. Therefore, the term “alga” is, along with the aforementioned eukaryotic life forms, to be understood also to include a cyanobacterium which lives in water and performs photosynthesis.
The at least one alga is preferably chosen from the group consisting of cyanophyceae (blue and green algae), chlorophyceae (green algae), bacillariophyceae (diatoms), and chrysophyceae (golden algae). For example, the at least one alga is chosen from isochrysis (golden-brown flagellate prymnesiophyceae), chaetoceros (diatom), chlorella (unicellular green alga) and/or arthrospira (spirulina—cyanobacterium (blue alga)).
More preferably, the at least one photosynthesizing life form is at least one microalga. Preferably the at least one alga is a spirulina alga and/or chlorella alga. Spirulina algae belong to the genus of cyanobacteria, which in the sense of the invention belong to the blue algae, whereas the chlorella alga is a fresh water alga.
Preferably the at least one photosynthesizing life form is contained in the bioreactor as a suspension culture. That means that the life form does not grow on glass or plastic, but rather as a suspension in a fluid medium. Each life form need not be present alone, however; the life forms can also be present as multicellular aggregates. The fluid medium is preferably water.
In another preferred embodiment, the bioreactor is designed as a plate reactor. The light in the bioreactor is thereby distributed more evenly. The plate reactor functions on the principle of an airlift reactor. The reactor features bubble columns through which air bubbles flow. Circulation is achieved through a controlled introduction of air within a structurally defined loop. Each individual life form thereby comes to a reactor surface for a short time and thus benefits from the light. The bioreactor is preferably configured such that the air is introduced from the bottom and exits through the top, relative to the intended operating position.
The bioreactor is preferably designed of multi-skin sheets which are provided with at least one membrane module through which the air stream flows. By means of the membrane modules, strong gassing of the life form interior the bioreactor can be avoided.
In a preferred embodiment, the air purifier further exhibits a lighting unit. This has the advantage that it can also reduce the CO₂content of the air when it is disposed in a dark room without light ingress. The lighting unit is preferably disposed on and/or in the bioreactor, correlating with the intended operating position of the air purifier. The lighting unit is preferably disposed within the bioreactor. Optimal and direct illumination of the bioreactor is thereby ensured. The registered light energy of the lighting unit directly correlates with the amount of CO₂to be converted, in order to enable optimal operation.
The lighting unit can be disposed coaxially in the bioreactor. In this case, it is preferable that the bioreactor is designed as a tube, at each end of which a membrane module is disposed respectively, through which the air stream flows. By means of the membrane modules, powerful gassing of the life form within the bioreactor can be avoided.
The lighting unit preferably features light-emitting diodes (LEDs). These are inexpensive. The lighting unit favorably features one or more LED panels.
In photosynthesis, all visible wavelengths of the electromagnetic spectrum are utilized. However, there are different types of chlorophyll, which are designed to absorb specific wavelengths of light. The color of the light is therefore a defining factor for energy usage. In particular, photosynthesizing life forms are designed to absorb red and blue light in order to conduct photosynthesis. In one preferred embodiment, the lighting unit is designed to emit wavelengths in the range of red light. Emission wavelengths of red light reside in a range from 620 to 780 nm.
In another preferred embodiment, the air purifier additionally features a humidifier and/or a moisture sensor. This allows the parameter of ambient humidity in the interior space to be regulated. This parameter is an essential factor for a person to feel comfortable in an interior space.
Preferably the air purifier also features a temperature sensor. This allows the temperature of the interior space to be regulated by means of the air purifier and/or by means of a heating unit of the building in which the interior space is located. The temperature is also an essential factor for a person to feel comfortable in an interior space.
In particular, when the air purifier features a humidifier, a moisture sensor, and a temperature sensor, the parameters of CO₂content of the interior air, temperature, and humidity can be controlled such that a person feels comfortable in the interior space. Then all three parameters—temperature, humidity, and CO₂content—can be adjusted, which is necessary for a person to feel comfortable in the interior space.
Preferably the air purifier also features a WLAN module. The WLAN module is preferably designed to be connected to a controller and/or regulator unit external to the air purifier, which is designed to control one or more parameters of the air purifier such as light entry into the bioreactor by means of the lighting unit, the operating power of the blower, the strength of the air stream flowing through the air purifier, a humidity level to be achieved in the interior space, and/or a temperature to be achieved in the interior space. For example, the controller and/or regulator unit can be a component of a SmartHome. Alternatively or additionally, the air purifier can also feature a control panel and/or one or more adjustment buttons or the like, by means of which the aforementioned parameter or parameters can be adjusted.
In one preferred embodiment, the device features a pump which is designed to supply the bioreactor with air from the housing, and thus from the interior space. The pump is preferably designed such that it can distribute air bubbles in the bioreactor, so that the contact time between the air and the at least one life form is optimized. The pump performance is preferably adjustable, so that it can be adapted to the interior space and also to the given CO₂load. Preferably the pump is designed and disposed such that the bioreactor and the life forms and water within can be circulated. Preferably the pump is disposed within the air purifier such that air from the blower is supplied to it. Preferably the pump is disposed between the bioreactor and the blower.
Preferably the device features a compressor which is designed to compress a CO₂concentration in the air stream, which is supplied to the life form in the bioreactor. In this way, the performance can be increased further.
In one preferred embodiment, the bioreactor can be attached to the lighting unit. If needed, the lighting unit and/or the container can be replaced by the user by removing it from the housing, without the user having to come into contact with the at least one life form. The risk of contamination, for example by microbes, bacteria, viruses, or the like, during replacement can be avoided. The container is preferably inserted as an inert, self-contained system, so that the entire container can be replaced by the user, without the user having to come into contact with the life form. The lighting unit and/or the bioreactor are therefore preferably connected to the housing in a removable manner, for example attached onto the housing. The user can thus replace the bioreactor, for example for recycling.
The air purifier is preferably designed as free-standing. The housing is preferably designed to stand freely on a surface such as a tabletop or the like.
The air purifier can be utilized as an air purifier in an interior space such as a living room, office, conference room, classroom, and the like, in which one or more people can reside. It is also conceivable that the air purifier is operated in a central heating system, ventilation system, air conditioning system, or air treatment system of a building, in which one or more people are not directly residing.
An exemplary embodiment of the invention schematically in the drawings and is described in greater detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings,

FIG. 1 shows a schematic depiction of components of an air purifier according to the invention;

FIG. 2 shows a schematic cross-sectional view of an air purifier with bioreactor; and

FIG. 3 shows a top view of an air purifier with bioreactor.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 presents a schematic depiction of components of the air purifier according to the invention. The air purifier features a housing 1. An intake (not shown) is disposed in the housing 1, which is designed for the intake of air into the housing 1. Furthermore, an exhaust (not shown) is disposed in the housing 1, which is designed for venting air from the housing 1. Furthermore, the air purifier features a blower 2 disposed within the housing 1 for generating an air stream, which flows from the intake to the exhaust, which is indicated by arrows.
After the air flows through the intake, the air flows through at least one filter 3 of the air purifier, which is designed to purify the air flowing from the intake to the exhaust by removing airborne contaminants such as dust, viruses, bacteria, microbes, pollen, odors, smoke, and/or organic compounds.
The air purifier furthermore features a humidifier 8 and a moisture sensor (not shown), so that the humidity in the interior space where the air purifier is located can be regulated. Additionally the air purifier features a temperature sensor (not shown).
The air purifier furthermore features a bioreactor 4, which is disposed on the housing 1, relative to the intended operating position of the air purifier. The bioreactor 4 is disposed such that it is downstream from the at least one filter 3 in the air stream. The air stream flows out of the exhaust of the housing 1 and into the bioreactor 4. The air flowing into and through the air purifier flows out of the bioreactor 4. In order to permit air intake and exhaust from the bioreactor 4, the bioreactor 4 features membrane modules (not shown), so that air can flow through the membranes.
The bioreactor 4 contains at least one life form 5, in particular at least one microalga, which is designed to at least partially convert CO₂contained in the air stream into O₂. A lighting unit 6 is disposed in the bioreactor 4, which is designed and intended to support and/or to effect the occurring photosynthesis by means of its light emissions.
The air purifier furthermore features a WLAN module 7, which is designed to connect to a control and/or regulator unit (not shown), which is designed to control one or more parameters of the air purifier such as light regulation in the bioreactor 4 by means of the lighting unit 6, the operating power of the blower 2, and the like.
FIG. 2 provides a schematic cross-sectional view of an additional design embodiment of an air purifier with bioreactor 4. The air purifier is designed for the regulation of CO₂content in an interior space and features a bioreactor 4, which comprises an intake (not shown) for intake of air from the interior space, an exhaust (not shown) for venting the air from the bioreactor 4, and life forms 5 which are designed to at least partially convert the CO₂contained in the air into O₂by means of photosynthesis. The conduction of interior air through the device is symbolized by arrows, wherein air containing CO₂is introduced into the device via the intake and air containing O₂is vented from the exhaust. The life forms 5 are microalgae, which are disposed as a suspension in water (not shown).
The device furthermore features a lighting unit 6, which is disposed in the bioreactor 4. It is arranged and designed such that the life forms 5 are irradiated with light.
The device furthermore features a pump 9, which is designed to supply the bioreactor 4 with air from the interior space. The pump 9 is preferably designed such that it can distribute air and CO₂bubbles 11 in the bioreactor 4.
The device optionally contains a blower 2 and a compressor 10. The optional blower 2 is designed to draw air from the interior space and supply it to the pump 9. The optional compressor 10 is designed to compress a CO₂concentration in the air stream, which is supplied to the life form 5 in the bioreactor 4.
The pump 9, the optional blower 2, and the optional compressor 10 are disposed in a housing 1, which serves as a table leg or foot.
FIG. 3 provides a top view of the air purifier shown in FIG. 2. A top view of the air purifier is shown, in relation to the intended operating position, wherein the life forms 5 and the housing are not included (for the sake of clarity). The bioreactor 4 is designed as multiple tubes with varying dimensions. Multiple tube-like lighting units 6 with varying diameters are disposed between the tubes, which are dimensioned and designed such that they fit between the tubes of the bioreactor 4. Tubes of the bioreactor 4 and the lighting units 6 are disposed in an alternating manner. In FIG. 2 only one lighting unit 6 and one tube of the bioreactor 4 are shown (for the sake of clarity).

Claims

1. An air purifier comprising:

a housing (1),

an intake built into the housing (1) and configured for an intake of air into the housing (1),

an exhaust built into the housing (1) and configured for venting of air out of the housing (1),

a blower (2) disposed in the housing for generating an air stream which flows from the intake to the exhaust,

a filter (3) configured to purify the air flowing from the intake to the exhaust, the filter including a bioreactor (4) disposed on or in the housing (1) such that the air stream flows through it, and containing at least one photosynthesizing life form (5) configured to at least partially convert CO2 contained in the air stream into O2 by photosynthesis.

2. The air purifier according to claim 1, wherein the at least one photosynthesizing life form (5) is at least one alga.

3. The air purifier according to claim 1, wherein the at least one photosynthesizing life form (5) is contained in the bioreactor (4) as a suspension culture.

4. The air purifier according to claim 1, wherein the bioreactor is composed of multi-skin sheets with at least one membrane module, through which the air stream flows.

5. The air purifier according to claim 1, further comprising a lighting unit (6).

6. The air purifier according to claim 5, wherein the lighting unit (6) comprises light-emitting diodes.

7. The air purifier according to claim 5, wherein the lighting unit is designed to emit wavelengths in the range of red light.

8. The air purifier according to claim 1, further comprising a WLAN module (7).

9. The air purifier according to claim 1, further comprising by a humidifier (8) or a moisture sensor.

10. The air purifier according to claim 1, further comprising a temperature sensor.

11. The air purifier according to claim 2, wherein the alga is a microalga.