DE102021119751A1 - Room air purifier with fog generator for ozone depletion - Google Patents

Abstract

The present invention relates to a room air cleaner, comprising an electrostatic precipitator, which has a counter electrode and an array of emission electrode needles, and is used to separate particles from the air to be cleaned while generating ozone, and a mist generator arranged in the air flow direction before, on or after the array for enriching the air to be cleaned with water droplets in order to break down at least part of the ozone generated.

Description

The present invention relates to a device, namely a room air cleaner, and a method for treating, in particular humidifying, cleaning and/or washing air, such as an air humidifier, an air cleaner, an air washer or the like. Furthermore, the present invention relates to an air treatment system with at least two room air cleaners connected in parallel and a method for air cleaning.

Generic air treatment devices are used to prepare, in particular to clean, humidify and/or wash air that is present in closed rooms and/or buildings. The air treatment devices can have numerous areas of application, for example in medical technology or in the health industry, especially in doctor's offices, isolation rooms, sick rooms, intensive care units or clean rooms, in private households, especially in bedrooms, living rooms, kitchens or children's rooms, in public or industrial buildings such as museums, theaters , government buildings or offices, and/or in mobility, for example for cleaning vehicle interiors, especially in taxis, rental cars or vehicle sharing concepts. For example, the air treatment devices are standing devices and/or small electrical devices that can be placed in buildings or rooms on the floor or on shelves such as tables.

As a rule, air purifiers are equipped with multi-layer filter systems. A highly effective particle filter is supplemented by additional filters so that the intake air is cleaned and freed from pollutants. Air washers, on the other hand, usually work without additional filters and lead the air through a water bath, where it is cleaned and humidified at the same time.

Increasingly high demands are being placed on air treatment. On the one hand, this has to do with tightening legal requirements and the steadily growing health awareness of the population. In particular, the fine dust present in the air, which has solid particles in the µg/m ³ range, has proven to be particularly critical. Particulate matter can also contain bacteria, pollen, viruses, spores, fibers or the like. There are generally two types of air handlers, passive air handlers and active air handlers. With passive air handlers, no additional energy is injected into the system to condition the air. Active air treatment devices are characterized by the fact that additional energy is expended to carry out the air treatment. Known air treatment devices are limited in their effectiveness with regard to air treatment. The passive systems in particular are not capable of effectively separating fine dust particles from the air.

Furthermore, approaches for air treatment devices in which the electro-precipitation technology is used already exist in the prior art. However, such systems have the fundamental disadvantage that dry particles and thus non-aerosols are difficult to collect on a counter-electrode and transport away. After contact with the counter-electrode, fine dust is either carried away by the air flow or “clumps” to form a non-electrically conductive mass on the counter-electrode. On the one hand, the degree of separation is heavily dependent on the aerodynamics of the air flow, and on the other hand, the function of the counter-electrode suffers due to the reduction in its required electrical conductivity.

When operating room air cleaning devices with electrostatic precipitators (electrostatic filters), ozone can be formed intentionally or unintentionally. For this reason, air conditioning systems generally do not generate ozone. For example, the German Lung Foundation warns against eliminating the bad smell of smoky rooms with ozone-generating air purifiers. The guideline VDI 6022 sheet 5 "Room air technology, indoor air quality - avoidance of allergenic loads - requirements for the testing and evaluation of technical devices and components that influence the breathing air" therefore recommends determining the ozone emission rate when using ionizers. There are also approaches that build on this, such as in EP 2 774 628 A1 described to decompose the generated ozone again via a downstream catalyst in order to prevent its release into the environment. However, catalytic converters are expensive, tend to clog and must be replaced regularly.

It is the object of the present invention to improve the disadvantages of the known prior art, in particular to provide a more cost-effective and/or less harmful room air cleaner, in particular with increased separation efficiency.

This object is solved by the features of the independent claims.

Thereafter, a room air cleaner for cleaning, humidifying and/or washing air is provided. The air can, for example, contain solid and/or liquid particles, in particular contamination ments be provided, which can be at least partially separated from the air by means of the room air cleaner according to the invention. The air is in particular air that is present in closed rooms and/or buildings, such as room air, and with which people can come into direct contact. For example, the room air cleaner is a small electrical device and/or a stand-alone device that can be set up or removed in buildings or rooms or that can be integrated into a room and/or building ventilation system, such as a vehicle interior ventilation system. In addition to the possibility that the room air cleaner can be designed as an independent device, in particular a stand-alone device, it is also possible to integrate the room air cleaner according to the invention in ventilation systems, extractor hoods or other ventilation systems arranged in a room in a building or in a room in a vehicle. The room air purifier may be able to remove liquid particles, such as fat or oil particles, as well as fine dust solid particles from the air, even for solid particle concentrations in the µg/m ³ range. In particular, the room air cleaner is able to comply with the fine dust limit values, with a fine dust limit value PM10 of 40 µg/m ³ being achievable, for example. Fine dust particles are understood to be particles with an aerodynamic diameter of 10 µm or smaller.

The room air cleaner according to the invention comprises an electrostatic precipitator, which serves to separate solid and/or liquid particles from the air to be cleaned while generating ozone and, in particular, to eliminate unpleasant odors. The electrostatic precipitator has a counter-electrode and an array of emission electrodes that allow the particles to be separated from the air. The emission electrodes can be designed as emission electrode needles.

The electrostatic precipitator can be designed as a plasma precipitator. The counter electrode and the emission electrodes can be insulated from each other and/or can each be made in one piece. The array of emission electrodes as a whole forms an emission electrode, also known as a spray electrode, and essentially serves to emit negatively charged particles in particular. The counter electrode, also known as the collecting electrode, forms the opposite pole. For example, the space between the emission electrode and the counter-electrode can be referred to as the separation space, in which the solid and/or liquid particles are separated from the air flow. During the operation of the electrostatic precipitator, a high electrical voltage is applied between the emission electrode and the counter-electrode, so that a high-voltage field is generated between the emission electrode and the counter-electrode. For example, the high voltage is in the range from 8 to 16 kV, in particular in the range from 11 to 14 kV. In particular, the electrostatic precipitator is operated below the breakdown or flashover voltage. The breakdown voltage, also known as the breakdown voltage, is the voltage that must be exceeded in order for a voltage breakdown to occur through a material or substance, for example an insulator or gas. For example, the principle of charge generation on which the electrostatic precipitator is based can be impact ionization. When the so-called corona onset field strength is exceeded, electrons exit the emission electrode and interact with the surrounding air molecules, resulting in the formation of a so-called negative corona. Free electrons present in the air are strongly accelerated in the electrostatic field of the corona, so that a gas discharge can occur. When the free electrons hit air molecules, further electrons can be split off or attached to the air molecules. The negative charges then move towards the neutrally charged counter-electrode. The counter-electrode can, for example, be grounded and/or at ground potential. When a particle-charged gas flow enters, the negatively charged charges accumulate on the particles. Due to the acting electrostatic force of the DC voltage field, which can be oriented transversely to the flow direction of the air through the room air cleaner, the negatively charged particles migrate in the direction of the counter-electrode, where they can release their charge and can be removed from the counter-electrode. In this way, the particles can be separated from the air flow. The present invention also covers versions in which instead of the negative corona or. of the negatively charged charges a positive corona or a positively charged charge is generated. To avoid repetition, the description of the invention is limited to the implementation of the negative charge situation.

The room air cleaner can have an air conveying device, in particular an air intake device such as a fan. A fan is generally understood to be a turbomachine that builds up a pressure ratio of between 1 and 1.3 between the suction and pressure sides in order to convey air. The air conveying device can be set up to suck in air from the environment and/or to convey air in the direction of the electrostatic precipitator. In particular, the air conveying device is able or intended to convey the air to be treated, in particular building and/or room air, into the room air cleaner ger to suck and to feed the electrostatic precipitator or to expose it to subject the air to be treated to an electrostatic precipitator process, to separate solid and/or liquid particles from the air to be treated and thus to clean the air to be treated. The air conveying device can be designed in such a way that the sucked-in air reaches speeds in the range from 2 m/s to 10 m/s. After passing through the electrostatic precipitator, the electrically charged air can flow through the room air cleaner at flow speeds in the range from 0.1 m/s to 0.5 m/s, in particular it can be transported.

The electrostatic precipitator can generate a stable DC voltage plasma with an electrical high-voltage field of the electrostatic precipitator in the range from 8 kV to 16 kV. The plasma current at the emission electrodes can be between 4 μA and 10 μA. At least part of the oxygen (O ₂ ) contained in the air to be cleaned is split into individual oxygen atoms by the negative charges generated in the electrostatic precipitator, which can then combine to form ozone (O ₃ ). the generation of a plasma, i.e. ozone as a by-product. The higher the voltage between the emission electrode and the counter electrode, the more ozone is produced as a by-product in the electrostatic precipitator.

In order to break down at least part of the ozone generated by the electrostatic precipitator so that it does not get into the environment, the room air cleaner according to the invention comprises a fog generator arranged in the air flow direction before, on or after the array of emission electrodes. The fog generator is used to enrich the air to be cleaned with water droplets. The fog generator makes it possible to break down at least part of the ozone generated. The ozone (O ₃ ) reacts with the water (H ₂ O) in the air to be cleaned and is converted into oxygen (O ₂ ) with the production of by-products such as hydroxide ions (OH) or hydrogen peroxide (H ₂ O ₂ ). . This means that the room air cleaner does not require any additional components, such as catalytic converters, downstream of the electrostatic precipitator in order to remove the ozone generated as a by-product from the air before it is released into the environment. Provision can be made for the smoke generator to be arranged in the immediate vicinity before, on or after the array of emission electrodes. In this way, the ozone produced can be reduced as close as possible to the source, so that damage to the remaining components, which are arranged in the air path of the air cleaner downstream of the electrostatic precipitator, can be prevented by the ozone. The smoke generator results in a more cost-effective and efficient construction of the room air cleaner compared to the prior art. If the smoke generator is arranged directly on the array of emission electrodes, the smoke generator can be arranged within the array between the individual emission electrodes, so that the air to be treated can be enriched with water at the same time as the air particles are charged by the electrostatic precipitator. The water in the air to be cleaned can lead to short circuits between the individual emission electrodes. Even if the water mist generator is arranged upstream of the array of emission electrodes in the air flow direction, short circuits can occur between the emission electrodes because there is already water in the air to be cleaned when the air to be cleaned enters the electrostatic precipitator. However, short circuits can be prevented from occurring if the water droplets have the same potential as the emission electrodes. Arranging the fog generator in the direction of flow immediately after the array offers the advantage that no short circuits can occur between the emission electrodes, because in this version the air to be cleaned is still in the area of the emission electrodes, i.e. at the time when the air particles are charged by the electrostatic precipitator not enriched with water droplets. As a result, the ozone can be converted into oxygen in a particularly reliable and safe manner. By enriching the air to be cleaned with water droplets, almost massless particles such as fine dust, viruses, ultrafine particles, spores, allergens, pollen or bacteria can also be given mass by the accumulation of water on the particles, so that they can be removed more quickly in the electrostatic precipitator migrate in the direction of the counter-electrode and can thus be deposited more effectively than in the prior art. The fog generator also serves to increase the degree of separation of the electrostatic precipitator. It can be provided that the fog generator is also used to wet the counter-electrode with liquid through condensation or agglomeration of the water droplets generated by the fog generator in order to bind the charged particles in the liquid on the counter-electrode and prevent the particles from Counter-electrode clump together or be taken away again by the air flow. An arrangement of the smoke generator in the air flow direction directly after the array of emission electrodes can also be advantageous here. On the one hand, the almost massless particles only move to the counter-electrode after the emission electrodes and not before or in the electrostatic precipitator, for example due to the weight of the water droplets. On the other hand, this means that the counter-electrode can be better treated with liquid liquid be wetted because the water mist is not already at least partially condensed in front of or on the emission electrodes.

According to an exemplary embodiment, the mist generator generates spray mist. Alternatively or additionally, the smoke generator is set up to supersaturate the air to be cleaned with water. Due to the spray, the water droplets are distributed particularly evenly in the air to be cleaned, so that a particularly large amount of ozone can be converted into oxygen. The conversion of ozone to oxygen is all the better, the denser the spray is or the more the air is oversaturated with water. Alternatively or additionally, the mist generator is designed as an ultrasonic mist generator or as a high-pressure water nozzle. In particular, the fog generator can be designed as an evaporator, vaporizer or atomizer.

According to a further exemplary embodiment, the fog generator is set up to produce water droplets with a size of at least 1 μm, in particular at least 5 μm, at least 10 μm or at least 20 μm and/or at most 100 μm, in particular at most 80 μm, 60 μm or at most 50 μm to create. Water droplets of this size are spherical after detachment from the fog generator due to the surface tension of the water. Thus, the preferred size of the water droplets can refer to the diameter of the water droplets.

In an exemplary embodiment, the room air cleaner includes a device for wetting the counter-electrode with liquid. The liquid wetting device can be provided to realize the wetting of the counter-electrode with liquid alone or together with the fog generator. The liquid wetting device can be designed, for example, as a nozzle or atomizer. In an exemplary development, the liquid wetting device and/or the mist generator is/are set up to form a liquid film on the counter-electrode that moves at least temporarily, in particular that flows continuously. It can be provided that the liquid film has a film thickness in the range from 0.1 mm to 1 mm.

In an exemplary development, the electrostatic precipitator and the liquid wetting device are matched to one another in such a way that particles charged by the electrostatic precipitator get into the liquid wetting the counter-electrode, in particular into the liquid film formed on the counter-electrode. The particles electrically charged by the electrostatic precipitator are attracted by its counter-electrode and can thus be caught in the liquid wetting and taken away by the liquid wetting, in particular the liquid film, and transported away, in particular while the air flow cleaned by it is carried on separately and finally released back into the environment becomes. The liquid wetting of the counter-electrode also has the advantage that the counter-electrode is cleaned, in particular rinsed, of dirt or deposits by means of the liquid. For example, the liquid wetting device can have operating states, such as an off state or a predetermined deactivated operating state, in which the counter-electrode is not wetted. The liquid is generally a flowable rinsing and/or collector medium, for example water, in particular also rainwater, a hygroscopic collecting material, such as sodium hydroxide dissolved in a liquid, a gel which is heated to a certain temperature, for example, so that a liquid state of aggregation is reached, such as a wax or the like, an ionic liquid, such as melted or dissolved salts, or highly viscous oils that are mixed with electrically conductive particles, such as copper, for example. For example, the liquid may have a predetermined minimum electrical conductivity, for example at least 0.005 S/m. When the counter-electrode is wetted with water, there is the advantage that the wetting can be generated particularly easily by the liquid wetting device and the fog generator together.

In an exemplary embodiment of the present invention, the room air cleaner includes a local liquid reservoir. By local is meant that the liquid reservoir is part of and/or directly associated with the room air cleaner as opposed to a separate liquid reservoir or supply. For example, the liquid reservoir is arranged below the electrostatic precipitator and/or below the liquid wetting device and/or below the mist generator. The liquid reservoir can serve to supply the liquid wetting device and/or the fog generator with liquid or water. On the one hand, this results in a compact structure for the room air cleaner, and on the other hand, the liquid can get back into the liquid reservoir in a structurally simple manner using the force of weight. In a further exemplary embodiment of the device according to the invention, the liquid reservoir is integrated into a liquid circuit in such a way that the liquid, which may contain particles, is returned to the liquid after wetting the counter-electrode Liquid storage can reach. The separated particles can be entrained by the liquid and transported to the liquid reservoir and collected there.

Known electrostatic precipitators generally have the disadvantage that they become clogged with the separated particles, ie become soiled, so that the separating effect of the electrostatic precipitator is reduced. The wetting liquid prevents the separated particles from accumulating and depositing on components of the electrostatic precipitator and carries the particles away in a targeted manner, namely into the liquid reservoir.

In a further exemplary embodiment, the fog generator and the electrostatic precipitator are arranged in relation to one another in such a way that the water droplets can reach the counter-electrode under the influence of the weight force, in particular downstream of the array of emission electrodes. For example, the smoke generator can be arranged on an upper side of the electrostatic precipitator in the vertical direction and the counter-electrode can be arranged on a lower side, ie under the smoke generator. Provision can be made for the mist generator to generate sufficient wetting on the counter-electrode in this way, even without an additional liquid-wetting device, in order to form a liquid film on the counter-electrode and to be able to use the associated effects and advantages.

In an exemplary embodiment, the room air cleaner also includes an air duct housing with an air inlet through which the air to be cleaned can enter the air duct housing. The air duct housing can be used to guide the air to be cleaned through the room air cleaner. The air duct housing can be aerodynamically shaped, so that the air flow can flow through the air duct housing without as many obstacles as possible and/or with the build-up of a dynamic pressure that is as low as possible. The air inlet can be designed as an opening within the air duct housing with any desired cross section. The air duct housing can also have an air outlet. Furthermore, the air duct housing can be designed in such a way that the air to be treated can enter the air duct housing from the side, in particular is sucked in, and can exit vertically upwards, in particular is conveyed out. In this embodiment, the array of emission electrodes is arranged in the area of the air inlet. Provision can be made for the array of emission electrodes to extend in the area of the air inlet transversely to a main direction of flow of the air to be cleaned. Provision can also be made for the smoke generator to be attached to the air duct housing, in particular in the area of the air inlet.

According to an exemplary embodiment, the air duct housing has a deflection structure downstream of the array of emission electrodes and/or the fog generator for deflecting the air flow to be cleaned by at least 180°. In an exemplary development, the deflection structure comprises a tangential cyclone or a spiral flow path delimitation, the inner walls of which continue the counter-electrode and are wetted with liquid at least in sections by the mist generator and/or the liquid wetting device and/or are electrically conductive at least in sections. In an exemplary development, the inner walls of the tangential cyclone or the spiral flow path delimitation are provided with a liquid film by the liquid wetting device and/or the mist generator. The deflection structure can be designed in such a way that it deflects the air flow by at least 225°, by at least 270°, by at least 315°, by at least 360°, or by a multiple thereof. Due to the deflection structure, the separation distance can be extended and the degree of separation of the room air cleaner can be improved.

According to a further exemplary embodiment, the deflection structure is designed in such a way that the water droplets introduced by the mist generator into the air to be cleaned agglomerate at the deflection structure, in particular under the influence of centrifugal force, and/or are deflected by the deflection structure while the air is being transported through the room air cleaner. In the air flow, the water droplets can be pressed radially outwards by the centrifugal force that occurs when the air to be cleaned flows through the deflection structure at a sufficient speed and thus wet the walls of the deflection structure with liquid. In particular, it can be provided that the agglomerated water droplets run along the deflection structure and, for example, are returned to the liquid reservoir below the deflection structure.

According to a further exemplary embodiment of the present invention, the array of emission electrodes of the electrostatic precipitator comprises at least two, in particular parallel, rows of at least five, at least ten or at least 15 emission electrodes, in particular emission electron needles. In this case, a distance between two adjacent emission electrodes in the same row can be in the range from 5 mm to 15 mm and/or a distance between two emission electrodes in adjacent rows can be in the range from 5 mm to 15 mm. This ensures that a uniform, in particular homogeneous, electrical field is reliably built up without the individual emission electrode needles influencing one another, in particular interfering with one another.

According to a further aspect of the present invention, an air treatment system with at least two room air cleaners according to the invention is provided. The room air cleaners are arranged in such a way that an air flow flowing into the air treatment system can be divided into the two room air cleaners. The air treatment system can be, for example, a small electrical device or a stand-alone device that is installed or installed in buildings or in rooms or that can be integrated into a room or building ventilation such as a vehicle interior ventilation. It is also possible for the air treatment system to be integrated into ventilation systems, exhaust hoods or other ventilation systems present in a room, a building or a room in a vehicle.

According to a further aspect of the present invention, which can be combined with the preceding aspects and exemplary embodiments, a method for air purification is provided. According to the invention, particles are electrically separated from the air to be cleaned in the method with the generation of ozone and the air to be cleaned is enriched with water before, during or after the electrodeposition in order to break down at least part of the ozone generated and to prevent the ozone in the environment reached.

It can be provided that the method is set up to clean the air with a room air cleaner according to the invention or an air treatment system according to the invention.

Preferred embodiments are specified in the dependent claims.

• 1 eine schematische Prinzipskizze eines erfindungsgemäßen Luftbehandlungssystems;
• 2 eine Draufsicht auf das Luftbehandlungssystem aus 1;
• 3 eine schematische Schnittansicht einer beispielhaften Ausführung eines erfindungsgemäßen Raumluftreinigers;
• 4 eine perspektivische Ansicht des Raumluftreinigers aus 3; und
• 5 eine Draufsicht auf den Raumluftreiniger aus den 3 und 4.

In the following, further properties, features and advantages of the invention are made clear by means of a description of preferred embodiments of the invention using the accompanying exemplary drawings, in which:

• 1 a schematic outline sketch of an air treatment system according to the invention;
• 2 Figure 1 shows a top view of the air handling system 1 ;
• 3 a schematic sectional view of an exemplary embodiment of a room air cleaner according to the invention;
• 4 A perspective view of the room air cleaner 3 ; and
• 5 a plan view of the room air cleaner from the 3 and 4 .

In the following description of exemplary embodiments, a room air cleaner according to the invention is generally given the reference number 1 and an air treatment system according to the invention is given the reference number 100 . The room air cleaner 1 can fulfill various functions depending on the operating state or by structurally simple expansion, namely air humidification, air purification, air washing and particle separation, which makes the air purification particularly effective. For the description of exemplary embodiments based on the 1 until 5 it can be assumed, for example, that the room air cleaner 1 is a standing device or a small electrical device which is primarily intended to be placed in building rooms, for example on a table or on a shelf.

In 1 1 is a perspective view of an exemplary embodiment of an air treatment system 100 according to the invention, which is a unit of six exemplary embodiments of room air cleaners 1 according to the invention. The room air cleaner 1, in particular their operation and the individual components are in terms of 3 until 5 explained in more detail. As in 1 can be seen, the six existing room air cleaners 1 are arranged in a circle and distributed evenly in the circumferential direction. Furthermore, all room air cleaners 1 are identical.

The room air cleaners 1 each essentially comprise the following components: an air guide housing 3; an electrostatic precipitator 5 arranged in the air duct housing 3 for separating liquid and/or solid particles from the air to be treated, which has a counter electrode 7 and an array 9 of emission electrodes 11; a mist generator 13 (in 1 covered by the air duct housing 3), which is used to break down ozone generated in the electrostatic precipitator 5, to wet the counter-electrode 7 with water and to improve the separation of almost massless particles such as fine dust, viruses, ultra-fine particles, spores, allergens, pollen or bacteria in the electrostatic precipitator 5 ; and a deflection structure 15 downstream of the array 9 of emission electrodes 11 for deflecting the air flow to be treated, which is electrically charged by the electrostatic precipitator 5, by at least 180° and for lengthening the separation distance of the room air cleaner 1.

The air duct housing 3 has an air inlet 17 with a rectangular cross section the array 9 of emission electrodes 11 extends over its width, ie transversely to the main inflow direction of the air flow to be treated. In this way, the air inlets 17 of the individual room air cleaners 1, due to their circular arrangement, form a circumferentially closed, ring-shaped air inlet via which air can enter the air treatment system 100 in a 360° circumferential extension.

The individual room air cleaners 1 can be coupled to one another via connection points 19, for example clipped, glued, screwed or otherwise fastened to one another. The connection points 19 can be implemented, for example, by the air duct housing 3 in the area of the lateral delimitation of the respective air inlets 17 .

The room air cleaner 1 and the air duct housing 3 also each include an air outlet 21 which, according to the exemplary embodiments, is formed as a round outlet nozzle or opening in the air duct housing 3 on a vertical upper side 23 of the room air cleaner 1 . The air-guiding housing 3 also has a funnel-like or cone-shaped dip tube 25, which is directly connected to the deflection structure 15 and opens into a liquid-collecting basin (not shown) that serves as a local liquid storage. The liquid from the mist generator 13 and/or the liquid from a liquid wetting device (not shown), which can be used in addition to the mist generator 13 for wetting the counter-electrode 7, can be collected in the liquid collecting basin. The immersion tube 25 is arranged concentrically with one another, for example with the fluid outlet 21 .

2 10 depicts a top view of the air handling system 100. FIG 1 is, in which the top 23 of the air duct housing 3 are omitted in order to provide a view of the interior of the room air cleaner 1 and in particular the mist generator 13. 2 FIG. 12 further illustrates the circular arrangement of the individual room air cleaners 1, which has a center point M in the center of the air treatment system 100. In the execution in the 1 and 2 the mist generator 13 comprises three high-pressure water nozzles 14 in each case, which are arranged directly behind the array 9 of emission electrodes 11 in the area of the air inlet 17 in the air flow direction. The high-pressure water nozzles 14 generate a water spray and are evenly distributed over the width of the air inlet 17, so that the entire air to be cleaned is enriched with spray or water droplets.

Referring to the 3 until 5 is the structure and operation of a room air cleaner according to the invention 1, as for example in the air treatment systems 100 of the invention 1 and 2 is present, and the individual components of the room air cleaner 1 explained in more detail.

The air to be treated enters the room air cleaner 1 or its air duct housing 3 via the air inlet 17. In particular in 3 it can be seen that the air duct housing 3 is constructed in several parts. The air duct housing 3 comprises an immersion tube 25, a base housing part 27 attached thereto and a cover part 29 attached thereto, which has a lateral fastening flange 31 which overlaps the base housing part 27 on the outside and thus fixes the cover part 29 on the base part 27.

The air guide housing 3 essentially serves to guide the air to be treated through the room air cleaner 1 in a targeted manner so that it can be treated. The array 9 of emission electrodes 11 is arranged at the air inlet 17 in order to electrically charge the air to be treated or the solid and/or liquid particles in it that are to be separated as early as possible, so that they migrate in the direction of the counter-electrode 7 as early as possible . The array 9 of emission electrodes 11 extends transversely to the flow direction of the air in order to be able to electrically charge all of the air to be cleaned that enters through the air inlet 17 . In the exemplary statements in the 3 until 5 the emission electrodes 11 are designed as thin, elongated emission electrode needles. The emission electrode needles are arranged on an upper side 32 of the electrostatic precipitator 5 . In particular from 5 It can be seen that the emission electrodes 11 of the array 9 are arranged in two rows 41 , 43 of twelve emission electrodes 11 each, which are arranged one behind the other in the direction of flow and each extend over the entire width of the air inlet 17 . The emission electrodes 11 of the two rows 41 , 43 are offset from one another in the width direction of the air inlet 17 . An emission electrode 11 in row 41 is located between two emission electrodes 11 in row 43, viewed transversely to the air flow direction. The distance between two emission electrodes 11 within a row can be between 5 mm and 15 mm. The distance between an emission electrode 11 in row 41 and an emission electrode 11 in row 43 can also be between 5 mm and 15 mm. The counter-electrode 7 of the electrostatic precipitator is in the versions in the 3 until 5 arranged below the emission electrodes 11 .

When the voltage between the emission electrodes 11 and the counter-electrode 7 is between 8 kV and 16 kV, ozone is produced as a by-product in the electrostatic precipitator 5 . The negative charges generated in the electrostatic precipitator 5, which accumulate on the particles contained in the air to be cleaned, which thus migrate downwards in the electrostatic precipitator 5 in the direction of the counter-electrode 7 and are separated from the air flow, split at least part of the air to be cleaned Oxygen (O ₂ ) contained in air into individual oxygen atoms, which can then combine to form ozone (O ₃ ).

Viewed in the direction of air flow, the array 9 of emission electrodes 11 is therefore the mist generator 13, which, as in the explanations in FIGS 1 and 2 consists of three high-pressure water nozzles 14, immediately downstream. In 3 It can be seen that the high-pressure water nozzles 14, like the emission electrodes 11, are fastened to the cover part 29 of the air-guiding housing 3 and are thus arranged above the counter-electrode 7. The high-pressure water nozzles 14 are used to generate a water spray and to enrich the air to be cleaned with water droplets. The water droplets preferably have a size between 5 μm and 50 μm. The ozone generated in the electrostatic precipitator 5 can be broken down by the water mist before it reaches the environment. The denser the spray is and the more the air to be cleaned is oversaturated with water, the more ozone can be broken down. The ozone generated in the electrostatic precipitator 5 reacts with the water in the air and is converted into oxygen. Due to the arrangement of the high-pressure water nozzles 14 in the immediate vicinity of the emission electrodes 11, the ozone is already converted into oxygen close to the source and cannot reach the other components of the room air cleaner 1, such as the deflection structure 15 or the outlet 21, which are arranged behind the fog generator 13 in the air flow direction to damage.

The mist generator 13 can also be used to wet the counter-electrode 7 with liquid by the water mist condensing and agglomerating on the counter-electrode 7 . In the statements in the 3 until 5 the counter-electrode 7 is arranged in the vertical direction below the emission electrodes 11 and the mist generator 13, as already described, so that the water droplets can reliably get down to the counter-electrode 7 and wet it due to the force of weight. The room air cleaner 1 can have an additional device for wetting the counter-electrode 7 with water (in the 1 until 5 not shown), which supports or enhances the liquid wetting of the counter-electrode 7 by the mist generator 13. The mist generator 13 and/or the liquid wetting device produce a continuously flowing liquid film on the counter-electrode 7, which has a film thickness in the range from 0.1 mm to 1 mm. Due to the wetting of the liquid, the particles charged by the electrostatic precipitator 5 are bound to the counter-electrode 7 without clumping together or being picked up again by the air flow after the separation.

Guided by the side walls 33, 35 of the air duct housing 3, the electrically charged air flow in the electrostatic precipitator 5 reaches the deflection structure 15 in a targeted manner, which is shaped in such a way that the air flow to be treated is deflected by at least 180°. The advantage is that it is possible to lengthen the separation distance in a way that is favorable in terms of installation space and thus to keep the degree of separation high even at high flow rates. In the exemplary statements in the 3 until 5 the deflection structure 15 is formed as a tangential cyclone. The inner walls 37 of the tangential cyclone are wetted with liquid by the mist generator 13 and optionally by the liquid wetting device, in that the water droplets are wetted under the influence of centrifugal force, which presses the water droplets out of the air flow radially outwards. The water droplets agglomerate on the inner walls 37 of the deflection structure 15 and form a liquid film there. Due to the force of gravity, the liquid runs down along the inner walls 37 via the immersion pipe 25 and finally reaches a liquid collecting tank (not shown) via a deflection screen 39 .

Due to the enrichment of the air with water droplets by the fog generator 13, almost massless particles such as fine dust, viruses, very fine particles, spores, allergens, pollen or bacteria can also be given mass by the accumulation of water on the particles, so that they can Electrostatic precipitators 5 move down faster in the direction of counter-electrode 7 and can thus be deposited more effectively than in the prior art.

The features disclosed in the above description, the figures and the claims can be important both individually and in any combination for the implementation of the invention in the various configurations.

Reference List

1

room air purifier

100

air treatment system

3

air guide housing

5

electrostatic precipitator

7

counter electrode

9

array

11

emission electrode

13

smoke generator

14

water jet

15

deflection structure

17

air inlet

19

connection point

21

air outlet

23

top

25

dip tube

27

base housing part

29

cover part

31

mounting flange

32

top

33

Side wall

35

Side wall

37

inner wall

39

deflection screen

41.43

Emission Electrode Rows

M

Focus

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• EP 2774628 A1 [0006]

Claims (12)

Room air cleaner (1) comprising: - An electrostatic precipitator (5), which has a counter-electrode (7) and an array (9) of emission electrodes (11) and serves to separate particles from the air to be cleaned while generating ozone; and - A fog generator (13) arranged in the air flow direction before, on or after the array (9) for enriching the air to be cleaned with water droplets in order to break down at least part of the ozone generated. Room air cleaner (1) after claim 1 , wherein the mist generator (13) generates spray mist and/or is set up to supersaturate the air to be cleaned with water and/or is designed as an ultrasonic mist generator or high-pressure water nozzle (14), with the mist generator (13) in particular being used as an evaporator, evaporator or Atomizer is formed. Room air cleaner (1) after claim 1 or 2 , wherein the fog generator (13) is set up to spray water droplets with a size of at least 1 µm, in particular at least 5 µm, at least 10 µm or at least 20 µm, and/or at most 100 µm, in particular at most 80 µm, 60 µm or at most 50 µm to produce. Room air cleaner (1) according to one of the preceding claims, further comprising a device for wetting the counter-electrode (7) with liquid, in particular the liquid wetting device being set up to create a liquid film, in particular at least temporarily moving, in particular continuously flowing, in particular with a film thickness in the range from 0.1 mm to 1 mm, on the counter-electrode (7), in particular the electrostatic precipitator (5) and the liquid wetting device being matched to one another in such a way that particles charged by the electrostatic precipitator (5) get into the counter-electrode (7) wetting liquid, in particular in a liquid film formed on the counter-electrode (7). Room air cleaner (1) according to one of the preceding claims, wherein the mist generator (13) and the electrostatic precipitator (5) are arranged in relation to one another in such a way that the water droplets can reach the counter-electrode (7) under the influence of the weight, in particular downstream of the array (9). Room air cleaner (1) according to one of the preceding claims, further comprising an air duct housing (3) with an air inlet (17) through which the air to be cleaned can enter the air duct housing (3), the array (9) in the region of the air inlet ( 17) is arranged, with the array (9) in particular extending transversely to a main inflow direction of the air to be cleaned. Room air cleaner (1) after claim 6 , wherein the air duct housing (3) has a deflection structure (15) downstream of the array (9) and/or the mist generator (13) for deflecting the air flow to be cleaned by at least 180°, with the deflection structure (15) in particular being a tangential cyclone or comprises a spiral flow path delimitation, the inner walls (37) of which continue the counter-electrode (7) and are at least partially wetted with liquid and/or are at least partially electrically conductive, in particular are provided with a liquid film. Room air cleaner (1) after claim 7 , wherein the deflection structure (15) is designed such that the water droplets agglomerate in particular under the influence of centrifugal force on the deflection structure (15) and/or are deflected by the deflection structure (15), in particular run along it. Room air cleaner (1) according to one of the preceding claims, wherein the array (9) has at least two, in particular parallel, rows (41, 43) of at least 5, in particular at least 10 or at least 15, emission electrodes (11), in particular emission electrode needles, with in particular one The distance between two adjacent emission electrodes (11) is in the range from 5 mm to 15 mm and/or the distance between two emission electrodes (11) in adjacent rows (41, 43) is in the range from 5 mm to 15 mm. Air treatment system (100) comprising at least two room air cleaners (1) designed according to one of the preceding claims, which are arranged such that an air flow flowing into the air treatment system (100) can be divided into the two room air cleaners (1). Method for cleaning room air, in particular by means of a room air cleaner (1) according to one of Claims 1 until 9 or an air treatment system (100). claim 10 , in which: - particles are electrically separated from the air to be cleaned while generating ozone; and - the air to be cleaned is enriched with water before, during or after the electrodeposition in order to break down at least part of the ozone generated. procedure after claim 11 , which is set up, corresponding to the room air purifier (1) after one of Claims 1 until 9 and/or according to the air treatment system (100). claim 10 to purify air.

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