Apparatus for making an air flow by ion-air wind

Rzeczpospolita. PATENT DESCRIPTION

POLAND

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OFFICE

PATENT

Polish

Additional patent to patent no. - Patent pending: 88 06 17 (P. 273152)

Priority -^:The application was announced: 89 12 27

Patent description published: 1991 09 30

153 456 Słijzbbw

Int. Cl.5 _{B03c 3 / θ2}H01T 23/00

Creators of the invention: Vilmos Tórók, Andrzej Loreth

Patent holder: ASTRA-VENT AB, Stockholm (Sweden)

A device for generating airflow by means of an ionic wind

The subject of the invention is a device for producing air flow by means of an ionic wind, in particular for cleaning air from aerosol and / or gaseous impurities and / or heating or cooling, using ionic wind or corona wind as a means of air displacement.

The method of moving air by means of an ionic wind or corona wind is known. The device built for this purpose contains a corona electrode and a bombarded electrode mutually spaced apart, each of which is connected to the appropriate output or pole of a DC voltage source.

The structure of the corona electrode, mutual potential difference and the distance between the corona electrode and the bombarded electrode should be such as to ensure the formation of a corona discharge at the corona electrode, producing air ions. The air ions produced in this way quickly move to the bombed electrode under the influence of the electric field located between the corona electrode and the bombed electrode, where they give off their charge. As they move along the road, the ions collide with electrically neutral air molecules and transfer electrostatic force to them, thereby attracting these air molecules to the bombed electrode and, thus, displacing the air in a manner known as ionic corona wind.

Air transport devices of this type are known from patent application PCT / SE 85/00538. It shows that it is possible to achieve significant velocities and air flow rates using ion or corona winds. High efficiency, however, is conditioned by large potential differences between the corona and the bombed electrode, necessary to maintain the corona discharge when the corona and the bombed electrodes are at a considerable distance from each other. The strong corona current, causing high-speed airflow with high efficiency, has the disadvantage of increased production of chemicals, in the form of ozone and nitrogen oxides, near the corona electrode. These compounds are irritating and even harmful to human health. That is why it is advisable

153 456 use of moderate corona currents and move the corona and bombarded electrodes far apart. The application PCT / SE 85/00538 shows that the corona electrode must be carefully shielded in known devices in order to prevent displacement of the generated air ions · directions other than towards the bombed electrode. However, it is desirable to achieve high volumetric capacities when the device is used not only for moving air, e.g. only as a fan, but also for the treatment of displaced air, e.g. by cleaning the air of impurities contained in it and / or changing its temperature, then there is no need to achieve high velocities of air flowing through this device. In fact, lower flow velocities are more preferable with this dual function of the device, because at lower flow velocities the air stays near the treatment devices for longer, making them more effective without the need for excessive axial elongation of the devices in the air flow direction.

The design of devices in which the corona and bombed electrodes are enclosed in the air flow duct, in which the air treatment devices are placed together with or behind the bombed electrode in the direction of air flow, which are the simplest constructions, have a serious disadvantage. For example, it has proved very difficult to achieve a uniform distribution of velocity over the entire cross-sectional area of ​​the air flow duct - Uneven distribution of velocity has a negative effect on the efficiency of air treatment devices. It is also difficult to eliminate the considerable resistance posed by the treatment devices to the air flow flowing through the conduit. This resistance makes it necessary to increase the potential difference between the corona and the bomb electrode in order to increase the corona current. This last action gives a serious negative effect in the form of increased production of ozone and nitrogen oxides. In addition, the walls of the cord surrounding the electrode system interfere with the operation of the corona electrode, e.g., prevent corona discharge and prevent the desired, effective corona current increase.

The object of the invention is to provide a construction for an improved device for generating air flow by means of an ionic wind.

A device for generating air flow by means of an ionic wind, containing a corona electrode consisting of an elongated thin wire, at least one air-permeated bomb electrode moved away from the corona electrode and a DC voltage source having one tip connected to the corona electrode and the other tip connected to the bomb electrode, and the voltage difference between the terminals of the voltage source is such that a corona discharge produces air ion producing air ions, according to the invention is characterized in that at least one electrode bombarded is arranged symmetrically around the corona electrode in a circle that concentrically surrounds the corona electrode.

Preferably, at least one bombarded electrode is positioned along the entire circumference of this circle and at least one bombarded electrode has a cylindrical shape. Preferably, the bombed electrode consists of a plurality of mutually separated parts that are connected to the other end of the voltage source and are mutually offset from each other around the circumference of the circle. Preferably, each of the bombed electrodes has an arcuate shape, and its arrangement along the circle is such as arranging along the circle the spacing between two adjacent bombarded electrodes. Preferably, each of the bombed electrodes has the shape of a fragment of a cylindrical surface. Preferably the bombed electrodes have a radius of curvature smaller than the radius of this circle. Preferably the corona electrode has a length greater than the axial length of the bombarded electrode.

Preferably, the device has means for separately removing air from the immediate vicinity of the corn electrode, which is a pipe with one end connected to the air intake device, and the opposite open end is axially oriented towards one end of the corn electrode wire. As an air removal unit, a pipe can be used

153 456 3 one open end is connected to a source of compressed air and the opposite open end is directed axially towards the opposite end of the corona electrode.

The air removal assembly may be a tube with a perforated wall, connected to an air intake device and aligned coaxially along the central axis of the circle, the corona electrode comprising a series of elongated thin wires arranged parallel to and around the tube. The air removal unit may be a series of pipes with perforated walls connected to the air intake device, the pipes being parallel to and around the corona electrode wire, or the air removal unit may be the air supply pipe to the corona electrode on one side, at right angles to the longitudinal direction of the electrode wire and a removal line by aspiration of air on the other side of the corona electrode in a direction perpendicular to the longitudinal direction of the corona electrode wire.

Preferably the device has an air heating assembly which is positioned near or radially to the outside of the bomb electrode.

Preferably the device has air treatment elements disposed at the respective open, axial end of the cylindrical electrode that can be placed at intervals between the bombed electrodes.

Preferably, the device comprises a series of cylindrical bomb electrodes having corona electrode wires arranged around a common axis in a mutually spaced apart arrangement to form an annular space between mutually adjacent bomb electrodes, while air treatment elements are placed in appropriate annular spaces, the radial distance between the corona electrode wire and the bomb electrode is at least 5 cm, preferably at least 8 cm.

Preferably, both axially positioned ends of the cylindrical electrode are open, and the axial length of the electrode is not greater than the radial length between the corona electrode and the bomb.

Preferably one axially positioned end of the cylindrical electrode is sealed and the opposite axially located end is open, and the axial length of the bomb electrode is not more than half the radial distance between the corona electrode and the bomb electrode.

The presented electrode system in which the M-bombarded electrode concentrically surrounds the K-crown electrode has a number of advantages. For example, in this system a corona discharge occurs symmetrically around the entire K corona electrode, which results in a much stronger total corona current, with the potential difference unchanged and the distance between the K corona electrode and the M-bombarded electrode unchanged, which may be obtained using crown and bomb electrode systems described in the above solution constituting the state of the art design. Alternatively, a small potential difference can be used with the corona current unchanged. As a result, the air will flow very slowly in close proximity to the K-crown electrode. This is very beneficial because it is much easier to neutralize harmful gases generated during corona discharge, such as ozone and nitrogen oxides.

Another very important advantage obtained by using the device according to the invention is the presence of large flow surfaces, e.g. through a cylindrical M-bomb electrode, which also reduces the flow velocity accordingly. These low flow rates are very beneficial because they enable effective air treatment, e.g. it can be effectively cleaned of aerosol and / or gaseous pollutants, it can also be heated or cooled using appropriate devices placed in the air flow path, placed adjacent, or placed radially outside the M-bombarded electrode in the form of a hollow cylinder, or at its open ends through which air enters the M-bombed electrode, or in both positions. Because the areas through which the air passes are extensive, the resistance of air treatment devices will not be as significant. In addition, since the K-crown electrode is completely surrounded by M-bombed electrodes, there are no effects that interfere with the operation of the K-crown electrode when it was with the M-bombarded electrode

153 456 surrounded by the walls of the flow conduit, and when the walls had an internal insulating surface and an external electrically conductive and grounded surface. It has been found to be advantageous if the length of the corona electrode K is such that the electrode protrudes axially beyond both axially located ends of the M-bombarded electrode. Compared with such an electrode system in which the K-crown electrode has the same axial length as the M-bombarded electrode, the longer K-crown electrode allows for a reduction of the potential difference between the K-crown electrode and the M-bombarded electrode with unchanged corona current and also for an increase in efficiency volumetric system.

The radial distance between the K-crown electrode and the M-bombarded electrode is suitably greater than 5 cm, preferably greater than 8 cm. Wprzypadkuprzedstawionymnafig. 1-4, the radius of the M-bomb electrode, i.e. the distance between the K-crown electrode and the M-bomb electrode can be approximately equal to the axial height of the M-bomb electrode. If the M-bomb electrode has a radius of e.g. 10 cm, the corona electrode may protrude, e.g. 3 - 4 cm beyond the axially located ends of the M-bombed electrode

The object of the invention is described in the drawing, in which Fig. 1 is a device for producing an air flow, in a first embodiment shown schematically in axial section; Figure 2 is a plan view of the device of Figure 1; Figure 3 is an axial cross-sectional view of the electrode bombarded in the second embodiment; Fig. 4 is a cross-sectional view of the bomb electrode in a third embodiment; FIG. 5 - the bomb electrode in the fourth embodiment in axial section; Figure 6 is a cross-sectional view of the bomb electrode in the fifth embodiment; Figure 7 is a co-operating device with a corona electrode for removing harmful gases, in a first embodiment in axial section; Figure 8 is a device cooperating with a corona electrode for removing harmful gases, in a second embodiment in axial section; FIG. 9 - a device cooperating with a crown electrode for removing harmful gases, in the third embodiment in axial section; Figure 10 is a device cooperating with a corona electrode for removing harmful gases, in a fourth embodiment in axial section; Figure 11 is an axial cross-sectional view of an air flow generating device; FIG. 12 - an apparatus for generating air flow, in a third embodiment, in axial section; Figure 13 is a radial cross-sectional view of the air flow generating device of the fourth embodiment; Fig. 14 is a radial cross-sectional view of the device for generating air flow in the fifth and sixth embodiments; 15 is a device cooperating with a corona electrode for removing harmful gases in the fifth embodiment in axial section.

The air treatment device schematically depicted, for example, in Figures 1 and 2, comprises a corona electrode K, consisting of a thin wire stretched between holders 1, respectively designed, shown only schematically. The device also has an M-bomb electrode, having the shape of a hollow cylinder, surrounding the corona electrode K and placed coaxially with this electrode K. In the embodiment shown in Fig. 1, the M-bombarded electrode is made of a loose mesh of electrically conductive or semi-conductive material, sandwiched between rings 2 of insulating material, e.g. rubber rings, conveniently supported, not shown. The K corona electrode and the M-bombarded electrode are connected to the corresponding output or pole of the DC 3 source, with the voltage and distance between the K-crown electrode and the M-bombarded, i.e. the radius of the M-bombed electrode is selected so that a corona discharge occurs at the K-crown electrode. This discharge produces ions that migrate to the M-bombarded electrode under the influence of the electric field thus generated, which in turn causes air to flow towards the M-bombarded electrode.

In the case of the device according to the invention, the discharge causes an air flow in the direction of arrow 4 in Fig. 1, i.e. the air enters through the open axial ends of the hollow cylindrical electrode M bombed and exits radially through its mesh wall.

153 456

As shown in Figure 1, the K-crown electrode and the M-bombarded electrode are connected to a voltage source 3 via ohmic resistors 5, which in the event of a short-circuit in the K-crown electrode or the M-bombarded electrode, e.g. as a result of accidental contact, limit the current resulting from this short circuit to safe value. This means that the system is not dangerous when touched. In order to prevent human contact with the K-electrode or M-bombarded electrode or to eliminate possible electrostatic fields in the system, protective gratings may be placed outside the axially open ends of the M-bombarded electrode. They can be made e.g. made of plastic or, when electrostatic screening is desired, made of conductive or semi-conductive material, in the case of conductive material, protective grates should be grounded. Protective gratings can be placed a few centimeters, viewed in the axial direction, from the ends of the K-crown electrode and stretched to the outer surfaces of the rims of the plastic rings 2. An undesirable flow of corona current to protective grids can be prevented by combining a K-crown electrode with a suitable positive or negative potential against the ground, while combining an M-bombarded electrode with a potential with opposite polarity to the ground, whereby such a connection significantly reduces insulation problems that can occur at high potentials relative to earth. In order to further protect the corona current against the outflow of the K crown electrode in undesirable directions, you can additionally use ring-shaped S shielding electrodes arranged axially in relation to the K crown electrode ends, these electrodes should be connected to the same potential as the K crown electrode. Such annular shielding electrodes S are schematically shown in Figure 1.

The M-bombed electrode according to the invention, for example shown in FIGS. 1 and 2, should consist of a loose mesh of electrically conductive or semi-conductive material, the current values ​​obtained with the M-bombarded electrodes are extremely small and the term "conductive or semi-conductive current in with respect to the material from which the M-bombarded electrode must be interpreted in this respect. Thus, the electrical conductivity of the material from which the M-bombarded electrode is made can be practically very low.

The M-bombed electrode may have a different system structure. For example, the M-bombed electrode may consist of axially arranged rods spaced at equal intervals in the form of a circle around the corona electrode K and arranged concentrically to this electrode. Alternatively, the plate elements of the electrode M or the layered elements of the electrode M can be arranged so that they are arranged axially and parallel to the corona electrode K, with the lateral surfaces of these elements running radially, i.e. parallel to the air flow directed radially through the M-bombarded electrode. The M-bombed electrode may also include a series of flat, ring-shaped electrodes arranged concentrically at equal axial spacing about the K-crown electrode. The M-bombarded electrode may also be in the form of a spirally arranged wire or plates concentrically arranged around the K-crown electrode.

The aforementioned air treatment devices may have various forms and are preferably arranged adjacent to the M-bombed electrode or placed radially outside this electrode. For example, air treatment devices may include a conventional mechanical filter for cleaning air of aerosol contaminants, i.e. particles or fluid droplets, or a chemically active filter, e.g. containing activated carbon to remove gaseous pollutants from the air. Because the aerosol contaminants contained in the air passing through the M-bombed electrode are electrically charged as a result of ion formation during corona discharge, they can be removed from this air stream in an electrostatic way. For this purpose, for example, a mesh structure can be used, e.g. in the form of a thin film of electrode material placed radially outside the M-bombed electrode. Because the M-bombarded electrode has the opposite polarity to the electrically charged erosion pollutants

153 These contaminants will tend to settle on the M-bombed electrode, so that it can be advantageously used as a surface for depositing contaminants in an electrostatic filter system, e.g. an electrostatic condenser separator. When it is desired to control the air flow temperature, e.g. heating or cooling of air, a suitably constructed ventilated heater can be placed radially outside the cylindrical M-bomb electrode.

Figures 3-6 schematically show embodiments of various possible M-struck electrode arrangements with various possible devices for treating the air flowing through the M electrode.

The M-bombed electrode in the electrode arrangement shown in FIG. 3 has the M-bombarded electrode previously discussed with reference to FIGS. 1 and 2. In the embodiment shown in FIG. 3, the M-bombarded electrode has a radially placed next R electrode in its hollow form a cylinder that is folded, e.g. from an open mesh of conductive or semi-conductive material, and which is grounded, thereby obtaining an electric potential with the same polarity as the M-bomb electrode and K-crown electrode. Aerosol contaminants in the air that have been charged as a result of ion formation tend to settle on an M-bombed electrode that has an electric polarity opposite to that of the electric charge. Those impurities that do not settle immediately on the M-electrode but pass through it will be returned towards the M-bombed electrode under the influence of the electric field generated between the M-bombed electrode and the further R electrode so that they settle on the M-bombarded electrode For this reason, it is necessary that the force exerted on the charge of the pollution by the electric field existing between the two electrodes M and R be able to overcome the force of the air flow directed radially and outwards through the M and R electrodes. This can be easily achieved by using a low air flow rate . The R electrode can therefore be treated as a reflecting electrode that reverses the direction of the charged impurities, thus effectively separating them from the air stream.

Figure 4 shows a similar device in which the grounded reflecting electrode R is located radially outside the M-bombarded electrode, although in this case the M-bombarded electrode consists of a series of flat ring-shaped elements that are arranged concentrically around the corona electrode K in equal axial spacing. The electrode elements of the M bombing electrode serve as electrostatic deposition surfaces for aerosol contaminants contained in the air stream, as in the previously described case. Thanks to this, a cleaning effect is achieved, which causes the M-electrode deposition surfaces to have a significant span in the air flow direction. Thus, the residence time of the charged impurities near the deposition surfaces is extended and they have greater access to these surfaces.

Figure 5 shows a device in which the M-bombarded electrode, as in the device of Figure 4, comprises a series of flat annular electrode elements that are arranged concentrically around the corona electrode K at mutually equal axial intervals. In the case of using the embodiment shown in Fig. 5, similarly flat annular electrode elements 6 are arranged between the electrode elements of the M-bombed electrode, which are grounded and together with the electrode elements of the M-bombarded electrode form an electrostatic capacitor separator of known type. The electrically charged aerosol contaminants present in the air move towards the M-bombarded electrode under the influence of the electric field existing between the M-bomb electrode elements and the 6 electrode elements and settle on the M-bomb electrode elements. Because the air flow speed is low, the residence time of the pollutants between the elements the M-bombed electrode and the electrode elements 6 is relatively long. This allows for effective air purification.

FIG. 6 shows a device similar to FIG. 3, the device of FIG. 6 comprises a M-struck electrode and a R-reflecting electrode placed radially outside the M-struck electrode. The M-struck electrode together with the reflecting electrode R form an electrostatic separator, which works extracting aerosol contaminants from the flow of air as shown in Fig. 3. The device shown in Fig. 6 also includes a heater 7 of suitable construction, which in the embodiment shown is in the form of a cylinder placed outside of the reflecting electrode R but enclosing it. The heater 7 allows you to change the air temperature, i.e. allows heating or cooling of air. Due to its large flow surface and low air flow rate, the heater 7 achieves very high efficiency and can be constructed to resist the air flow that passes through it as little as possible. Because aerosol contaminants are effectively emitted from the air stream at the M-bombed electrode, the heater 7 will remain clean, so it does not need to be cleaned or replaced. It is necessary to clean the M-bombed electrode or replace the electrode at regular intervals. The heater 7 can be constructed so that it is itself a reflection electrode, by grounding the wire. This allows the R reflecting electrode to be grounded.

In devices constructed according to the invention, the air flow velocity near the K-crown electrode is very low, which allows for easy and effective removal and disposal of harmful gases, primarily ozone and nitrogen oxides, produced during the corona discharge. This can be done, for example, by using the device shown in Fig. 7. The crown electrode of claim 7, wherein the corona electrode K is in the form of a wire and is supported in a suitable manner (not shown) along the central axis of the cylindrical electrode being bombarded (not shown in figure 7). To the ends of the K-crown electrode are attached small, sleeve-like elements 8 containing a chemically active substance, e.g. activated carbon, which can absorb or catalytically decompose harmful gases such as ozone or nitrogen oxides. This can be achieved by applying a slight air flow in the immediate vicinity of the K-crown electrode. As shown in Fig. 7, these chemically active absorption elements 8 can be electrically connected with a slightly lower potential than the K-crown electrode, whereby the elements 8 will act as excitation electrodes or excitation elements, enabling the corona discharge at the K-crown electrode to be maintained, with a reduced potential difference between the corona electrode K and the M-bombed electrode

Figure 8 schematically shows a device for removing harmful gas near the corona electrode K that has been generated at the corona electrode K. This device includes a tube 9 which is connected by an air nozzle (not shown), e.g. a fan or air pump, and its inlet 9a is directed axially towards one end of the K-crown electrode so that the air layer containing harmful gases around the K-crown electrode so that the air layer containing harmful gases around the K-crown electrode continuously sucked through tube 9. Because the air flow around the K-crown electrode is very small, only a small amount of gas will be drawn through the tube 9. The air sucked through the tube 9, together with the harmful gases carried, can be discharged into the air purifying device from these gases, or it can be discharged to another place where these gases will no longer pose a threat. As shown in Fig. 8, the tube 10 connected to the compressed air source can be placed at the opposite end of the corona electrode K so as to direct the air stream along the corona electrode K towards and inside the suction tube 9. This ensures more efficient movement of harmful gases generated by corona discharge. Tubes 9 and 19 can also be used as excitatory electrodes when at least the ends of the tubes are electrically conductive and connected with a potential slightly lower than the potential of the corona electrode K.

Figure 9 schematically shows an embodiment of a K-crown electrode for a similar purpose, comprising a perforated tube 11 positioned along the central axis of the cylindrical electrode M-bombarded. The perforated tube 11 is connected to a suitable suction device (not shown), sucking air like the tube 9 in the device with fig. 8. In the case of the device of fig. 9, the end of the tube 11 is closed so that air is only sucked through the perforation in the wall of the tube 9. In this case, the corona electrode K

153 456 consists of a series of wire-like electrode elements K arranged parallel to and around the tube 11 so that the corona current propagates in all directions to the surrounding electrode M bombarded (not shown in Figure 9). In order to reduce the necessary potential difference between the K-crown electrode and the M-bombed electrode, tube 11 can also serve as the K-electrode excitation electrode if the tube 11 is made of electrically conductive or semi-conductive material and connected with a potential slightly less than the potential of the K-crown electrode .

As shown schematically in Fig. 10, the inverse design can be used to remove ozone and nitrogen oxides from the immediate vicinity of the K-crown electrode. In the embodiment in Fig. 10 a number of perforated tubes 16, e.g. three or four, are arranged in parallel to and around the K crown electrode, the tubes 16 being connected to air suction devices so as to draw in the air that is directly in the vicinity of the K crown electrode through the perforated walls of the respective tubes 16. Tubes 16 can also act as corona electrode excitation electrodes if they are made of electrically conductive or semi-conductive materials and connected with a potential slightly less than the potential of the corona electrode K.

The distance between the corona electrode K and the M-bombarded electrode, i.e. the radius of the M-bombarded electrode in the device constructed according to FIGS. 1 and 2 is determined by the potential difference between the K-crown electrode and the M-bombarded electrode and the desired value of the corona current. Thus, in the case of Figures 1 and 2, it is impossible to increase the total volumetric capacity only by increasing the size of the device, and thus the diameter of the M-bombarded electrode. The volumetric increase in capacity requires the use of a device with an increased axial length. However, the axial elongation of the device would reduce the inlet surface with the axially located open ends of the cylindrical M-electrode relative to the outlet surface through the cylindrical mesh surface of this electrode, resulting in increased flow resistance and possibly uneven air flow through the M-bombarded electrodes.

The device shown schematically in Fig. 11 shows a solution to this problem. This embodiment comprises a series of air-driving units 12, each of which is constructed in accordance with the previously described embodiment of Figures 1, 2. The units 12 are arranged axially, mutually spaced apart, so that there is space between adjacent units 12 through which air can enter the units 12 as indicated by the arrows in Fig. 11. This embodiment of the device according to the invention may also include air treatment devices, e.g. a cylindrical convector and / or a chemical absorbing means 13, arranged around the air-driving units 12 and the spacing between them so that both incoming and outgoing air passes through the convector 14 or other air treatment device placed in the same way.

Another example of a device constructed according to the invention is schematically and in axial section in Fig. 12. This embodiment differs from the embodiments described above in Figs. 1 and 2 in that one axially arranged end of the M-bombarded electrode is closed by a flat impermeable plate 15, which replaces the plastic ring 2. The central part of the round plate 15 contains insulating material, used to attach one end of the corona electrode K. At a certain radial distance from the central part of the round plate 15, there is conductive or semi-conductive material or a coating of such grounding material. The M-bombed electrode, in the embodiment shown in Fig. 12, is constructed in a manner corresponding to the electrode of Fig. 5. It also has a grounded annular electrode element 6, as in Fig. 5. Thus, the air flow through the device shown in Fig. 12 will follow the path indicated by arrows 4. In the device constructed in this way, the axial height of the M-bomb should be approximately half from the axial height of the M-bombed electrode of the device shown in Figures 1 and 2.

Figure 13 shows schematically and in radial section an alternative embodiment of the device according to the invention which may have a larger axial dimension to increase the overall

153 456 volumetric capacity. In this embodiment, the M-bombarded electrode is divided into a series of arc elements M1 and M2, two of which are shown, placed at an equal circumferential distance around the cylindrical surface surrounding the coaxial crown electrode K such that they form a space 14 between the elements of the bombarded electrode M1 and M2 . Air flows through this system in the directions indicated in Fig. 13 by the arrows, i.e. radially through the spaces 14 between the elements M1 and M2 and flows out radially through these electrode elements. The flow area of ​​the respective spaces 14 is equal to the flow area through the elements M1 and M2 of the bombed electrode. In the case of the embodiment according to Fig. 13, wherein two or more elements are arranged concentrically around the central corona electrode K, the radius of curvature of the arcuate electrodes bombarded with M1, M2 should preferably be shorter than the radial distance from the corona electrode K, i.e. such that the ends of the respective arcuate electrodes M1, M2 at a smaller distance from the K-crown electrode than their central parts.

It has been found that this design ensures a more uniform dispersion of the air flow throughout the entire area of ​​M1 and M2 bombarded electrodes.

Figure 14 also shows two different embodiments of arcuated bombed electrodes.

The M1-bombarded electrode shown on the left in Fig. 14 comprises a series of elements in the form of plates or plaques arranged mutually parallel to each other and perpendicular to the axial direction of the corona electrode K in the same way as shown in Fig. 4. In this embodiment additional electrode elements that are grounded and correspond to the electrode elements 6 shown in Fig. 5 can be arranged between the elements of the M-bombarded electrode. The M2-bombarded electrode shown on the right of Figure 14 comprises a series of electrode elements 18 in the form of plates or plaques arranged axially between the insulating end plates 17, one of which is shown in the drawing, and which are oriented radially with respect to the corona electrode K. The M1 elements of the bombarded electrode are separated by electrode elements 18 in the form of plates or plaques, arranged in a similar way as the M2 elements of the bombarded electrode, but grounded. These electrode elements 18 perform the same function as the electrode elements 6 described in Fig. 5. Together with the elements M2 they form a condenser separator. It is advantageous if these additional electrodes 18 are positioned at a slightly greater distance from the corona electrode K than the M2 elements of the bombarded electrode so that the corona current does not in large part pass to the electrode elements 18.

Ozone and nitrogen oxides can be very effectively removed from the immediate environment of the K-crown electrode using the devices shown in Figures 13 and 14, by blowing air above the K-crown electrode on one side, through a slotted pipe 19 connected to a source of compressed air, while its suction from the other side of the corona electrode K through a similar slotted tube 20 connected to an air nozzle. Wires 19 and 20 have holes 19a and 20a, respectively, facing the corona electrode K, having the shape of a slit and extending along the entire length of the corona electrode K in a direction perpendicular to the plane of the drawing. Cables 19 and 20 will not noticeably interfere with the corona discharge at the K corona electrode, nor will they noticeably affect the necessary potential difference between the K corona electrode and the M-bombarded electrode. Wires 19 and 20 can also function as K-electrode excitation electrodes in the manner previously described if at least those portions of wires 19 and 20 that are closest to the K-crown electrode conduct or conduct semiconducting electricity and are connected with a potential slightly lower than the potential K. corona electrode

The device shown in the embodiment shown in Figs. 13 and 14 has advantages similar to those of devices constructed in accordance with the embodiments shown in Figs. 1, 2 or 12.

Figure 15 schematically shows a similar device for the disposal of harmful gases that have been formed in the vicinity of the corona electrode K due to corona discharge. In this embodiment, the K-crown electrode is surrounded concentrically by a number of axially spaced, annular plates 21 containing a chemically active substance or coated with a chemically active substance capable of absorbing or decomposing.

153 456 catalytically harmful gases formed during corona discharge. Since the air flow around the corona electrode K is very small, the plates 21 can very effectively neutralize gases.

The air ions generated by the corona discharge are able to move freely towards the M-bombarded electrode (not shown in Fig. 15) between the annular plates 21. In order to prevent the screening effect of the plates 21 on the K corona electrode and, thus, to interfere with the corona discharge, plates 21 are grounded through a strong resistor 22 to dissipate the electrical charges received by plates 21. The plates 21 may contain 'conductive, semi-conductive or insulating material.

Other components containing chemically active substances that absorb or decompose catalytically harmful gases may be arranged around the K-crown electrode, provided that their structure allows free flow of ions. In addition, these structural elements are connected by an electrical potential selected so that shielding of the K crown electrode does not occur.

The number of M-arched electrodes may be greater than two, for example three or four. For example, the electrodes M1 and M2 bombarded with the example shown in Fig. 13 are connected respectively to the reflecting elements of the electrodes R1 and R2, as shown in Fig. 3. The air treatment devices can be arranged in or next to the space 14, which serve as holes air intake. In the case of a device constructed as shown schematically in Fig. 14 or 13, it is more preferable to close the axially arranged ends of the system to prevent air from entering through these ends.