HU203620B - Air delivering apparatus - Google Patents

Abstract

The electric ion-powered air conveyor is more advanced a corona discharge electrode (K) and including at least one target electrode (M) that is permeable for air in the equipment and which is spaced apart from the crown discharge electrode (K) with respect to the desired air flow direction, Behind. There is also a DC voltage a power source (3), one of which is an acoustic discharge electrode (K), and the other terminal to the target electrode (M) is connected electrode (K) structure and DC power source (3) terminal voltage is such that air ions crowning out of the crowning out electrode (K). The corona discharge electrode (K) is shielded from the air flow direction so as to counteract the air flow of the ionic current in the same direction and current ion current from the corona discharge electrode (K) it is a product of a routine migration, in deminden case it is much smaller than the crown removal electrode (K) in the air flow direction Advanced Ion Stream Strength as well as This Ion Migration Route. as target (M) part of the ionic current at least 50 mm, but preferably at least 80 mm. (Figure 4)

Description

BACKGROUND OF THE INVENTION by means of an ion wind or a corona discharge wind, an electric wind, comprising at least one corona discharge electrode and at least one target electrode, an anti-cathode, which passes through the apparatus 5 condensate flowing air spaced from the corona discharge electrode and in the desired air flow direction a DC voltage source having one terminal connected to the corona discharge electrode and the other terminal 10 being connected to the target electrode, and the voltage between the corona discharge electrode structure and the power supply terminal terminals is such that a corona discharge occurs during the generation of air ions. 15

The apparatus is primarily designed for use in air purifying devices such as electrostatic precipitators and air sterilization systems such as ventilation systems and air conditioning systems, but the invention is also useful in other aspects where air is to be transported, such as electrical equipment. and for cooling electrical appliances, or for heating appliances such as electric hot air heaters. 25

Nowadays, in the listed equipment and systems, air is transported almost exclusively by mechanical means, using various types of fans. These mechanical fans and the associated drive motors are relatively expensive and require considerable weight and considerable space. In addition, they require high energy and are consequently expensive to operate. During operation, these fans make a lot of noise, which is a major problem in many applications, such as living areas and many workplaces.

It is known that the transfer of air can in principle be effected by means of the so-called ion wind or the corona discharge wind - the electric wind. Such an ion beam 40 is formed by placing a corona discharge electrode and a target electrode - an anticode - at a suitable distance from each other and connecting both to the appropriate output of a DC voltage source, and forming the corona discharge electrode and the DC power source. corona discharge electrode results in corona discharge.

This corona discharge causes the ionization of the air, with ions of the same polarity as the corona discharge electrode, and possibly electrically charged so-called. aerosols, that is, when solid or liquid particles in the air are electrically charged during their contact with electrically charged air ions. The air ions move rapidly from the corona discharge electrode to the target electrode under the effect of an electric field, where they lose their electrical charge and are converted back into electrically neutral air molecules. During their passage between the electrodes, the air ions continually collide with the electrically neutral air molecules, while electrostatic forces are also transmitted to these latter air molecules, which together with the air ions drift from the corona discharge electrode to the target electrode, thereby called. in the form of an ion wind or a corona discharge wind - an electric wind.

Such ion-beam air transport units are known in the art, and examples thereof can be found by describing and describing such devices, for example, in U.S. Patent Nos. 2,854,716, 2,538,959 DE, 2,112,582 GB, 29,421EP and 4,380,720 U.S. Pat. Patent Specifications. However, these state-of-the-art air transport units utilize the ion beam or corona discharge bar used with very little efficiency and have not achieved practical significance. The reason for this seems to be the lack of understanding of the physical mechanism that is decisive for the air transport through this type of equipment. As a result, such proposed ion-driven air transport units have not been able to deliver significant amounts of air in practice without increasing the corona discharge current to levels that are significantly higher than would be acceptable if equipment is used in a residential environment. It is well known, including in electrostatic dust deposition fields, that corona discharge produces chemical compounds, primarily ozone and oxides of nitrogen, that are irritating to human beings and which may be harmful to human health if airborne are present in too high concentrations. In the case of corona discharge, these chemical compounds are formed in a proportion that depends on the magnitude and polarity of the electrical corona discharge current. Consequently, the existing electrostatic air filters used in human or residential environments operate with positive corona discharge and the amperage of the corona discharge current is substantially proportional to the amount of air passing through the filter under normal operating conditions. From this point of view, the magnitude of the corona discharge current is 40-80 μΑ for 100 mTh air transport, and the amperage is adapted to an acceptable level of ozone and No Observed. It should be understood that the corona discharge current used in ion-driven airborne equipment, when used in the presence of humans, that is to say, in a residential environment, should be limited to the aforementioned magnitude. This cannot be achieved with current ion-beam air transport equipment due to its low efficiency. For example, EP 129,421 and EP 4,380

No. 720 In US patented equipment, it is reported that air supply of 11 / s can be achieved with 1W corona discharge energy, preferably with an i kV corona discharge voltage. Thus, if I converted it to 100 mTh of air-carrying capacity, this unit would be approx. It consumes 1900 μΑ, which is roughly thirty times higher than the corona discharge current acceptable in the human environment.

Accordingly, it is an object of the present invention to improve and render much more efficient an air-handling device of the kind described in the introduction which is so effective that, in practice, it is capable of delivering human air.

can also be used.

The apparatus according to the invention has been previously disclosed

-2HU 203620Β is based on a much more thorough and refined recognition of its decisive mechanism for the complete air transport through this type of equipment, which can be summarized as follows: the corona discharge electrode is shielded by a shielding electrode in the opposite direction to the air flow. multiplied by the product of the ionic current in the direction of the corona and the migration path of the ion current from the corona discharge electrode is practically zero, but in many cases much less than the product of the ionic current traveling from the corona discharge electrode to the air flow between the corona discharge electrode and the portion of the target electrode which receives the majority of the ion current, at least 50 mm, but preferably at least 80 mm.

In a further embodiment, the electrically conductive shield electrode is located upstream of the corona discharge electrode and has the same polarity as the corona discharge electrode with respect to the target electrode.

According to the invention, the shielding electrode is electrically connected to the corona discharge electrode. To achieve the shielding effect, at least the corona discharge electrode is disposed in an air flow conduit having walls made of dielectric material and extending upstream of the corona discharge electrode by airflow at least equal to the distance between the corona discharge electrode and the target electrode 1, 5 times.

According to another aspect of the invention, the air flow conduit is provided with partitions made of dielectric material upstream of the corona discharge electrode and extending substantially parallel to the longitudinal extension of the air flow conduit.

The apparatus of the present invention comprises an excitation electrode positioned near the corona discharge electrode at a distance less than the target electrode, and the excitation electrode is coupled to the same polarity potential as the target electrode potential and the corona discharge electrode. The portion of the total ion flow from the side that passes to the excitation electrode is substantially smaller than that portion of this total ion flow to the target electrode.

The potential difference between the excitation electrode and the corona discharge electrode is smaller than the potential difference between the target electrode and the corona discharge electrode, and the excitation electrode is connected to a DC voltage source which is connected to the target electrode through a high-value resistor.

In another aspect, the target electrode is proximal to the corona discharge electrode and serves as an excitation electrode extending axially to the corona discharge electrode, and the electrode conductive material of the target electrode has a high specific resistance and is less distal to one of the corona discharge electrodes.

It is a feature of the present invention that the target electrode is provided with excitation electrode portions extending axially proximal to the corona discharge electrode and extending axially toward the corona discharge electrode, which is substantially less electrically conductive than the target electrode. a substantially axially spaced portion thereof, wherein said greater portion is connected to a terminal of a DC voltage source.

Further features are that the target electrode and the optional excitation electrode consist of electrically conductive surfaces which are parallel to the direction of air flow and surround the path of the air flow.

In one embodiment of the invention, the target electrode and optionally the excitation electrode and shield electrodes are located in the air flow conduit, and the target electrode comprises electrically conductive surfaces on the wall of the air flow conduit.

In another embodiment, the corona discharge electrode, the target electrode, and the shielding electrode are disposed within the airflow conduit, the electrode conductor surfaces being electrically conductive, parallel to the airflow conduit wall and spaced inwardly to the airflow. The conductor wall is made of electrically insulating material and has an earthed, electrically conductive surface located outside it.

In a further embodiment of the invention, the corona discharge electrode, the target electrode and the shield electrode are disposed in the air flow conduit, the wall of the air flow conduit having at least one electrically conductive inner surface, preferably earthed, and electrically conductive surfaces of the target electrode. which are parallel to, but substantially spaced inwardly from, the air flow conduit wall, and the target electrode and the corona discharge electrode are connected to a potential of opposite polarity to earth.

In the apparatus according to the invention, the air flow duct is entirely electrically conductive or its wall is electrically insulating and has only an inner surface provided with an electrically conductive, preferably earthed, layer which is axially approximately downstream of the corona discharge electrode and target electrode. spread.

The distance between the airflow line wall and the nearest surface of the target electrode is approximately 50% of the cross-sectional area of the target electrode, and at least a portion of the inner surface of the airflow line is provided with a layer of chemically absorbent material or water or chemically active liquid. moistened. The temperature of the air flow duct wall is controlled.

The target electrode, the corona discharge electrode, and the shield electrode are at higher potentials relative to earth and the DC voltage3

-3HU 203620 20 are connected to a resistor through a resistor, and the short-circuit current through the resistor is less than or equal to 300 μΑ when the target electrode, corona discharge electrode, or shield electrode is grounded. 5

In the apparatus of the present invention, the electrodes are of high capacitance and their potentials differ significantly from the ground potential, and they are made of a material of high specific resistance limiting the capacitive discharge current produced by contact. The corona discharge electrode and the target electrode are bonded to a potential of opposite polarity to earth.

According to another embodiment of the invention, the corona discharge electrode extends diagonally across the air stream, and further has an electrically conductive surface of the target electrode that surrounds and is parallel to said flow path, and is closest to the conducting surface of the corona discharge electrode and target electrode. the axial distance between the disposed edges at the locations opposite the ends of the corona discharge electrode is less than at the locations opposite the center of the corona discharge electrode.

In another embodiment, the corona discharge electrode 25 extends diagonally across the airflow conduit, further comprising an electrically conductive surface surrounding and parallel to said airflow path, and finally the corona discharge electrode and the excitation surface electrode 30. the axial distance between adjacent edges at locations opposite to the ends of the corona discharge electrode is shorter than at locations opposite to the center portion of the corona discharge electrode. 35

Finally, in accordance with a preferred embodiment of the invention, the electrically conductive surfaces of the excitation electrode are parallel to the air flow path, and finally the electrically conductive layers forming the excitation electrode are disposed substantially perpendicular to the ends of the corona discharge electrode.

The invention will now be described in more detail with reference to its exemplary embodiments, of which:

Figure 1 schematically illustrates ion migration - 45 migration - between the corona discharge electrode and the target electrode; the

2-7. 9-13 and FIGS. FIGS. 50 to 5 are schematic diagrams of various embodiments of the apparatus of the present invention;

Figure 8 is a diagram showing the corona discharge current as a function of voltage.

First, a summary of the basic conditions for maintaining air transport by ion wind or crown discharge wind 55, an electrical wind created between the crown discharge electrode K and the target electrode M, will be given in FIG. The latter is located behind the corona discharge electrode K in the desired flow direction. Figure 1 schematically illustrates a corona discharge electrode K, in this case consisting of a thin wire and extending through the air stream, e.g. transverse to the conduit, and a target electrode M also transverse to the air flow path shown schematically. in a mesh or grid structure that is permeable to air. The target electrode M is located behind the corona discharge electrode K with respect to the desired airflow direction, indicated by an arrow w, at an axial distance H thereto.

As noted above, the corona discharge on the K corona discharge electrode increases the electrically charged air ions which migrate to the target electrode under the influence of the electric field between the K corona discharge electrode and the target M electrode.

The mobility of the ions varies over a wide spectrum, although for the present purpose, lightweight ions with a mobility of c <2.5.10 ^- 4i3cs and that electrically charged aerosols that are far less mobile than air ions are believed to be predominant they make up a negligible part of the total charge in the system. It can also be assumed that the air ions represent only a small fraction of the total amount of air in the system, and that the air flow rate is at least ten times lower than the velocity of the air ions. Thus, given the migration rate of air ions, ambient air can be assumed to be stationary.

The rate of migration (migration) of electrically charged air ions relative to ambient air is proportional to the product of their mobility c and the field strength E of the electric field, and hence v-c.E (l)

It is also assumed that the stationary conditions are such that the charge density occurs at a given volume of the system, which means that the electrical charge fed to the system over a period of time is equal to the charge exiting the system. Therefore, the current density in the air can be expressed as the product of the charge migration rate v and the charge density p, i-p.v (2) where i is the current density.

The specific volumetric force in the air is the product of the density p of the electric field and the strength E of the electric field, γy f-p.E (3) where f is the driving force per unit volume of air.

If Equations (1) and (2) and (3) are used, we get f / i / c4, so the specific volume force can be expressed,

-4HU 203620Β as the ratio of current to ion mobility.

As shown in Fig. 1, let us now consider a "flow channel" that directs an infinitely small portion d1 of the total ion current I between the corona discharge electrode K and the target electrodes M. The center line of this flow channel is always parallel to the current density vector i, and its surface perpendicular to the cross sectional area dS is parallel to the current density vector.

Now let's consider a volume element of this flow channel:

dV-dS.dl (5) where dV is an infinitely small volume and dl is an infinitely small length in the direction of the flow channel. For each such volume element in the flow channel, the force acting in the normal direction of its surface will be dF-f.dV-f.dS.dl (6)

This volumetric force dF has a component pointing in the air transport direction w and a component perpendicular to that direction. Suppose that when summing across the cross-sectional area of the air flow or flow channel, these transverse forces cancel each other out and are thus negligible. It follows that the total transport force in the flow channel is:

Μ M dFTL jw.dF- jw.f.dS.dlK K

Μ M

-) w.i / c.dS.dl-dI / c) w.dl-H / c.dI (7)

K K where H is the migration distance, i.e. the distance between the corona discharge electrode K and the target electrode M, in the direction of air flow.

The total FT transport force in the air flow duct can now be expressed

FT- (JdFT-H / c.I (8)

S where S is the total cross-sectional area of the air flow channel and the total ion current or corona discharge current I.

so the average pressure structure can now be written:

Áp-FTS-H / c.I / s (9) thus, the transport force is proportional to the product of the total ion or corona discharge current I and its migration path H, i.e. proportional to the so-called. HJ “with flow distance.

It can be seen that the total air transfer as a result of this pressure build-up can be written as:

Q- .I.H.S (IO) c.k.gA where Q is the air passage, Grace dimensionless aerodynamic drag coefficient and yAa is the specific gravity of the air.

It can be seen from equation (1) that the magnitude of the air transfer is directly proportional to the square root of the total ion current or corona discharge current I and the migration distance H.

Thus, in order to obtain high air transfer in a desired direction, i.e., from the corona discharge electrode to the target electrode M, we must strive to have a large ion flow in the direction from the corona discharge electrode K, ie the product of the migration distance H. The transmission force, and thus the increase in total air transfer, can be achieved by increasing either the total ion current I or the distance between the corona discharge electrode K and the target electrode M. As mentioned above, when used in a human inhabited environment, it is not permissible to raise the I or the corona discharge current to a level that is greater than the given maximum with harmful levels of ozone and nitrogen oxides. It follows that the only parameter which influences this is the migration distance H of the corona discharge, i.e. the axial distance between the corona discharge electrode and the target electrode M. Accordingly, according to the invention, that the corona discharge electrode K and the portion of the target electrode M which take up the major part of the ion current I are at least 50 mm and preferably at least 80 mm apart.

It will also be appreciated that when an air transport device of the type described above is used, the flow of air ions is able to migrate from the corona discharge electrode K to the air flow, i.e. upstream from the corona discharge electrode, i.e. upstream, i.e. - an electrically conductive object or device is provided which has an electrical potential relative to the corona discharge electrode K which permits such migration of air ions. It will be appreciated that this significantly reduces the desired total airflow through the unit. To the extent that the flow of ions from the corona discharge electrode K to the flow is taken into account in the design of the apparatus discussed above, it seems satisfactory to ensure that the electrically conductive object placed upstream of the corona discharge electrode K at a significant distance from the electrode and to keep the ion flow to the air current small. However, since the transport force generated by the ion flow is proportional to the product of the flow force and the distance traveled by it, as can be seen from equation (9) above, it can also be seen that even a very small ion flow,

-5HU 203620Β

It moves from the corona discharge electrode K to the air stream, and can generate a significant transport force in the opposite direction of the air transport if this flow of ionic currents is flowing over a long distance.

In this context, it should be noted that the term "electrically conductive" is to be understood to apply also to extremely low currents such as those present in this type of equipment, which are normally in the order of 1 mA / iu. As a result, in the case of the present type of air conveying equipment, to which the present invention relates, objects which are considered electrically conductive or have a surface which can be considered electrically conductive must in practice always be upstream, i.e. in front of the corona discharge electrode. These objects may, for example, be of lattice or mesh structure, or other components of the apparatus itself may be located at the inlet of the air flow conduit 1 of the apparatus. Even in the absence of such equipment components, objects such as wall surfaces, pieces of equipment or furniture or even people present in the area in which the equipment is located and adjacent to the air inlet 1 of the equipment may also serve. as electrically conductive surfaces to which the ion current I may travel from the corona discharge electrode K in the conductor to the flow.

This serves to improve efficiency, that is, by means of a corona discharge current limited to an acceptable value, high airflow can be achieved by the air conveyor device of the present invention, in part by positioning the target electrode M at a distance from the corona discharge electrode The portion of the target electrode M that absorbs the majority of the ion current, i.e., the flow path of the ion current flowing downward from the corona discharge electrode K, should be at least 50 mm, preferably at least 80 mm, partly by ensuring that the ion from the corona discharge electrode power and migration path is practically zero, or at least much less, than the airflow ion current from the K corona discharge electrode the product of the migration distance of the orphan H. The latter flow, starting from the corona discharge electrode according to the invention, is created by effectively shielding the corona discharge electrode in the direction opposite to the air flow so that the ion flow from the corona discharge electrode K small and wandering only a very short distance.

In one embodiment of the invention, said necessary shielding of the K-discharge electrode K in the opposite direction to the air flow is achieved by connecting the output of a DC voltage source 3 connected to the K-discharge electrode K to a potential substantially equal to the immediate environment of the apparatus. grounded in the same way as the equipment casing and other ionic electrical components Just as it was previously suggested for this type of air transport equipment to place the K-crown discharge electrode at ground potential or potential, these two variants were previously considered equivalent to the air transport mechanism and placing the K crown discharge electrode at ground potential has not been shown to be effective in the airflow of the K crown discharge electrode shade against a lamb.

In many cases, however, it is undesirable to connect the K corona discharge electrode to ground potential, since for various practical reasons it would be desirable to switch the target M electrode to earth potential or to connect the K corona discharge electrode and target M to polarity opposite to earth. the need for high voltage insulation. In such cases, an airflow shielding of the corona discharge electrode K may be achieved by another method known in the art of electrical engineering by inserting an electrically conductive baffle from the corona discharge electrode K in the direction opposite to the airflow. switch, which substantially coincides with the potential of the K-discharge electrode K, so that the K-discharge electrode K creates an equipotenic barrier to the air current that is substantially impermeable to ions traveling to the air flow. In addition to applying a shielding electrode S to the corona discharge electrode K and bonding it to the same point as said electrode as suggested above with respect to the air transport equipment in question, the same suggestion is made for the air transport equipment with cascade construction where A target electrode M is arranged in the air flow conduit 1 in the axial order. Prior to this, it has not been observed or recognized that effective shielding of the K corona discharge electrode against the counterflow ion flow in all circumstances is essential to the efficiency of the air transport device.

A third and extremely surprising embodiment of the required shielding of the corona discharge electrode K against an unwanted ion flow in the direction opposite to the air flow lies in extending the air flow conduit 1 which surrounds the electrodes of the apparatus up to a distance from the corona discharge electrode that is, at the inlet end of the air flow conduit 1, where the walls of this conduit preferably consist of dielectric material, such as suitable plastics, in a known and obvious manner. Tests have shown that, when operating this type of air conveyor, the dielectric walls of the air flow conduit 1 exhibit an excess electrical surface charge-6HU 203620,, which remains as long as the material is exposed to the prevailing electric field. By "charge surplus" in this case is meant the electrical charge on the surface of the dielectric material which is added to the surface charges taken up in the classical sense by dielectric materials with low electrical conductivity. It is not yet clearly explained why these surcharges occur on the dielectric walls of the air flow conduit 1, although the phenomenon itself has been experimentally created. This phenomenon seems to refer to the phenomena used in the manufacture of dielectric electrodes. In the latter case, special dielectric material is exposed to the combination of a strong electric field and an ion current. The electrical surcharges, meanwhile, are permanently bonded to the structure of the material and are not conductive despite the fact that the material is electrically conductive to some degree. Consequently, in connection with the above-mentioned phenomenon, which is encountered in the air transport equipment in question, it is obvious to a person skilled in the art that the electrical surge on the dielectric walls of the air flow conduit 1 is bound to the structure of the dielectric material. exposed to an electric field. This phenomenon can be advantageously utilized to provide the necessary shielding of the corona discharge electrode K in the opposite direction to the airflow by extending the airflow conduit 1 and its dielectric walls away from the direction of the airflow, i.e., at the end of the over a distance such that excess charges appearing on the walls of the wire during the ion flow from the K corona discharge electrode effectively shield the ion cloud around the K corona discharge electrode to create an electric field that is opposed to the air current from the K corona discharge electrode create an ion current from the K-discharge electrode opposite to the airflow. It can be seen that the greater the length of the airflow conduit 1 from the corona discharge electrode K to the airflow, the greater the shielding efficiency. Tests have shown that a satisfactory shielding effect can be achieved if the distance through which the air flow conduit 1 is extended from the corona discharge electrode K to the airflow is at least 1.5 times the distance between the corona discharge electrode K and the target electrode M. You can also see that the shading! the effect becomes even more effective by reducing the opening size of the air flow conduit 1, i.e., the smaller the mutual distance between the opposing dielectric walls, the greater the shielding effect provided. In the case of a relatively large cross-section airflow duct, the shielding effect can be substantially increased by dividing the ducts from the corona discharge electrode K into a plurality of parallel conduits facing the airflow by longitudinal dividing walls 12, e.g. these partitions 7 may be strips or the like of dielectric material. Such a device allows effective shielding of the corona discharge electrode K against the ion current traveling in the opposite direction to the airflow, even though the distance that the airflow conduit 1 extends from the corona discharge electrode K to the airflow is only close to the target of the corona discharge electrode K distance.

Another serious problem we encounter with this type of air handling unit when it is intended to be used in a residential environment is the need to protect it from contact due to the high voltage applied. Naturally, the contact protection can be achieved by mechanical means by providing the air flow conduit 1 surrounding the electrodes of the apparatus with completely impermeable walls and by installing the air flow conduit 1 with protective grids G (Fig. 10) at both its inlet and outlet ends. the live electrodes of the equipment must not be touched accidentally or intentionally. However, such protective devices represent a serious resistance to flow and thus severely impair the air transport through the device as well as its efficiency. However, it has been found that it is possible to provide perfectly satisfactory safety precautions against contact with the device according to the invention in a much simpler and more advantageous manner. As previously described, the apparatus of the present invention operates at very low corona discharge currents in the order of 20-50 μΐηΑ / 100 m / h of air supplied. This extremely low specific corona discharge current is made possible by the large axial distance between the corona discharge electrode K and the target electrode M and the effective shielding of the corona discharge electrode K in the upstream direction. As a result of this low current consumption, the energized electrodes of the apparatus, whether it be the corona discharge electrode K or the target electrode M, can be connected to the power supply terminals through extremely high resistance without the need to increase the voltage of the power source unacceptably. It has now been found that these serial resistors 8 are ready, without difficulty, with any resistance value of such magnitude that, when the live electrode is short-circuited directly, the short-circuit current is so low that it is completely harmless. A limit of 2 mA is normally prescribed with respect to the harmless short-circuit current at equivalent electrical equipment in contact with the body. If the short-circuit current is approx. Keeping it at 100-300 μΑ, you will not feel any discomfort when touching the live electrodes. This can be achieved with the apparatus of the invention. For example, assuming the operating voltage of the electrodes to be energized by the equipment is 20 kV and the crown current is 50 μΑ, then the electrode to be energized can be connected to the power source.

-7GB 203620Β should be properly terminated through a resistor, for example 150 ΜΩ, so that the voltage source itself must have a terminal voltage of 27.5 kV. If the electrode to be energized is short-circuited, the short-circuiting current 5 is thus only approx. 185, which is so small that it does not cause discomfort if the short circuit is caused by direct contact with the electrode.

Limiting the short-circuit current to a noticeable amount that does not cause discomfort when a person contacts the live electrode directly is, however, practically impracticable at high corona discharge currents, e.g. in the order of 2,000, as is necessarily the case with ion beam winding airborne equipment known in the art.

In addition to keeping the short-circuit current low, another characteristic factor of contact protection measures is the capacitive discharge current 20 that can be generated when an electrode of a given capacity is touched. However, for electrodes intended for this purpose, which have a significant capacity, the capacitive discharge current can be reduced to a perfectly acceptable level by making these electrodes of high specific resistance material according to the invention. This does not add to the other drawbacks, since the electrodes do not have to be good conductors in view of the low amperages which can be used within the scope of the invention, which can still provide an efficient air transport device.

Figure 2 schematically illustrates a schematic structure of a first embodiment of an air transport device according to the invention. This apparatus consists of an air flow conduit 35 1 made of an electrically insulating material through which an air flow is to be created in the direction indicated by the arrow 2.

The airflow conduit 1 is provided with a corona discharge electrode K, which is permeable to the airflow 40, while a downstream electrode M is located downstream, i.e. behind, of this corona discharge electrode K, which can also be passed through. The corona discharge electrode K contains an electrically conductive material which is preferably resistant to ozone and ultraviolet radiation and can be formed in a number of known ways to provide an electrical corona discharge under the influence of an electric field. For example, the embodiment of the corona discharge electrode K shown in Fig. 2.50 comprises a thin wire or yarn which extends through the air flow conduit 1. However, the K crown discharge electrode can be made in many other forms. For example, it may consist of a plurality of thin wires or 55 yarns which are either arranged parallel to each other or form a grid or mesh with open meshes. Instead of straight, thin wires or yarns, helically wound wires or thin tapes that extend straight, but may also have serrated or fluted edges, may be used. The corona discharge electrode K may further comprise one or more needle-shaped electrode elements located substantially axially 65 on the air flow conduit 1. The target electrode M, the anti-cathode, contains an electrically conductive or semiconductor material or is made of a material which is electrically conductive or semiconductor coated and has a surface that does not result in an increase in the strong concentration of the electric field. The target electrode M can also be made in a variety of known designs, depending in part on the design of the corona discharge electrode. In the embodiment shown in Fig. 2, the target electrode M, for example, consists of two parallel plates disposed in the direction of the air flow conduit 1. In the case where the corona discharge electrode K is also provided with needle-like portions, the target electrode M is preferably cylindrical in shape and is aligned with the air flow conduit 1.

The electrically conductive surface coating formed on the inside of the air flow conduit 1 may also serve as a target electrode M f. The target electrode M may be provided with a plurality of planar or cylindrical electrode elements disposed adjacent to each other and having a side surface substantially parallel to the longitudinal axis of the air flow conduit l. the target electrode M may comprise straight or helically wound wires, or straight bars which are mutually parallel or cross each other to form a lattice structure or may be in the form of a perforated disk. However, it is particularly advantageous if the target electrode M is an electrically conductive or semiconductor surface which surrounds the air flow conduit 1 in a frame-like manner and has at least one-fifth of the distance between the corona discharge electrode K and the target electrode M .

The exemplary K-discharge and M-target electrode designs described above can, in principle, be used in all embodiments of the apparatus of the invention described below.

In the embodiment shown in Fig. 2, the corona discharge electrode K and the target electrode M are connected in a conventional manner to the respective pole or terminal of the DC source 3. In the example, the corona discharge electrode K is connected to the positive terminal of the DC voltage source 3 to produce a positive corona discharge. Theoretically, however, the polarity of the DC source 3 may be contrary to the fact that negative corona discharge produces less ozone than negative discharge and ozone is a toxic gas.

2, the terminal of the DC power source 3 connected to the corona discharge electrode K is grounded in accordance with the present invention so that the potential of the corona discharge electrode K is substantially the same for all electrically inactive portions of the apparatus and its immediate environment.

The potential of the corona discharge electrode K in the fly mode will be the same as the environmental potential of the corona discharge electrode K in the opposite direction to the airflow, at any electrically conductive object or surface placed therein, and thus no unwanted ion flow from the corona discharge electrode.

As mentioned above, the distance is K

Between the corona discharge electrode 203620Β and the portion of the target electrode M which holds the weight-bearing portion of the ion flow, at least 50 mm, and preferably at least 80 mm, with air transported through the air flow conduit 1 of e.g. of low magnitude, which is an acceptable value for the formation of ozone and nitrogen oxides. Further, as discussed above, it is advantageous if the target electrode M is connected to the DC power source 3 via a large limiting resistor 8, which limits the short-circuit current to a maximum of 300 μΑ in the event of a short-circuit caused by touching the target electrode. Since the target electrode M does not have a negligible capacity as a result of its construction, it can accordingly be made of a high-resistance material. A material that is high in this respect and which has a high resistance and at the same time has the necessary electrical conductivity, for example a plastic material, which can be a precisely selected electrically conductive material, such as carbon black. Known materials of this kind, from which M target electrodes can be made, have a surface resistance of 100 kfl or more.

It will be appreciated from the foregoing that the apparatus of the present invention, such as that shown in FIG. 2, is completely non-contacting and therefore no safety measure or protective device is required to prevent intentional or accidental contact with either the K-discharge electrode K or the target electrode M. . Further, the target electrode M is formed of a high-resistance material to limit the capacitive discharge current when the target electrode M is touched.

Tests made with the apparatus produced as shown in Figure 3 have shown that the apparatus is very efficient in transporting air in the direction indicated by the arrow 2 in the environment surrounded by the target electrode M. The apparatus under investigation is surrounded by a rectangular, transverse target M electrode. The apparatus under investigation was equipped with a rectangular target frame M having a cross-sectional area of 600x60 mm and an axial length of 25 mm. The distance between the target electrode M and the corona discharge electrode K was 100 mm. A voltage of 25 kV was applied to the target electrode M and the corona discharge current was 30 μΑ. The DC voltage of the 3 DC braids was 29 kV and the series 8 resistor was 132 ΜΩ. This very simple device resulted in airflow 60 m ^J / h through the area enclosed by the target pipe M field. If the target electrode M of the device was short-circuited, we found that the short-circuit! current is only »220 μΑ, which is an amount of current hardly perceptible when one touches the target M electrode. The device is thus perfectly contact safe, provided that the DC power source 3 itself is protected against contact.

As mentioned above, there are many instances where it is undesirable that the K crown discharge electrode be bonded to ground potential. In such cases, for the purposes of the present invention, the required shielding of the K-discharge electrode K is a

In the exemplary embodiment shown in Figure 4, it can be seen as follows. In this apparatus, the negative terminal of the DC power source 3, together with the target electrode M, is grounded, while the corona discharge electrode K is connected to the positive terminal via a large resistor 8, which serves to limit the short-circuit current to an acceptable value. in the event of a short circuit upon contact of the K discharge electrode K. In order to prevent ion migration from the corona discharge electrode K to the air flow, a shielding electrode S is disposed upwardly from the corona discharge electrode K upstream of the air flow so that the shield electrode S and the electrode K are interposed. The shielding electrode S can be made in many different shapes, depending on the structure of the K koro20 discharge electrode used. If the corona discharge electrode K contains a thin, straight wire, the shielding electrode S may, for example, be a rod or a wire formed in a coil shape. The shielding electrode S may comprise a plurality of rods or wires which are arranged in parallel to one another or may be arranged in a diamond shape. .Shielding electrode S may be mesh or grid construction. In one embodiment, the shielding electrode S comprises six electrically conductive surfaces disposed adjacent to or on the inner surface of the air flow conduit 1.

Theoretically, the shielding electrode S may have a geometric shape and be positioned relative to the corona electrode 35 so that? The shielding electrode S forms an equipotential barrier surface that is impermeable to ions emanating from the K corona discharge electrode.

The shielding electrode S need not be electrically connected directly to the corona discharge electrode K but may be connected to one of the terminals of an additional 4 DC power source as shown in FIG. 5, such that the shielding electrode S has the same polarity as K a corona discharge electrode relative to the target electrode M, preferably at a potential substantially equal to that of the corona discharge electrode K. In addition, the shielding electrode S is connected to a DC resistor 4 via a large resistor 9, which limits the short-circuit current generated in contact with the shielding electrode S.

It can be seen that in the embodiment shown in Fig. 5, when the shielding electrode S has a higher positive potential relative to the target electrode M than the corona discharge electrode K, it can also effectively prevent ion flow from the corona discharge vessel K in contrast to airflow. Even if the shielding electrode S has a slightly lower positive potential than the K-corona discharge electrode, so that a small amount of ion flow from the K-corona discharge electrode K to the flux-shielding electrode S may be acceptable,

-9EN 203620Β provided that there is only a small distance between the corona discharge electrode K and the shielding electrode S, so that the distance through which the ion current travels in relation to the air current and so on. current path is very short.

It will be appreciated that if the shielding electrode S shown in Figures 4 or 5 is of such a high capacity and is preferably made of a material with high specific resistance, the capacitive discharge current can be limited to an acceptable level if contacted with the electrode. This can generally be applied to all live electrodes in a device according to the invention provided that these electrodes do not have a significant capacity. However, the corona discharge electrode is normally designed to be of very low capacitance and is thus incapable of significantly increasing the capacitive discharge currents. Another generally applicable feature is that all the electrodes of the apparatus of the invention which are connected to a non-earthed terminal of the DC power source 3,4 are preferably connected via a resistor 8,9 of a magnitude such that upon contact with the electrode the short-circuit current is limited to a maximum of 300 μΑ.

As discussed above, the desired shielding of the K-corona discharge electrode against unwanted ion current in the air stream can also be accomplished electrostatically, as shown in Figure 6. In this embodiment, the air flow conduit 1, the walls of which are made of dielectric material such as a suitable plastic material, extends a considerable length from the corona discharge electrode K against the air flow. When the apparatus is in the operating position, an excess surface charge is created on the walls of the air flow duct zl, which provides an effective shield against the ion cloud surrounding the corona discharge electrode K, provided that the air flow conduit 1 protrudes sufficiently from the corona discharge electrode. in the opposite direction of said air flow. This effectively prevents ion current migration from the K corona discharge electrode to the air stream. The shielding efficiency can be further improved by dividing the air flow conduit 1 into a plurality of conduit portions by partitions, panels or strips 7 of dielectric material along the length of the conduit, as shown schematically in FIG. In order to provide effective shielding, the length of the airflow conduits 1, which is in the opposite direction to the airflow from the corona discharge electrode K, should be at least equal to the distance of the corona discharge electrode K from the target electrode M, but preferably 1.5 -fold. The length of the air flow conduit 1 required for effective and well-functioning shielding depends on the geometry of this air conduit 1, in particular its cross-sectional shape and the presence or absence of dielectric baffles 7 in the air flow conduit upstream of the corona discharge electrode. . Generally speaking, it should also be noted that the needs and requirements for shielding the K-discharge electrode K depend on the potential difference between the K-discharge electrode and its grounded environment; with a smaller potential difference, the shielding requirements are reduced.

If the corona discharge electrode K of the air transport device of the present invention is effectively shielded by one of the above described modes, i.e., substantially no ion flow from the corona discharge electrode K to the air flow direction, the efficiency of transport through the apparatus to the corona discharge electrode K is dependent on the transport force generated by the current ion current and is proportional to this ion current multiplied by the distance between the corona discharge electrode K and the target electrode M.

As the distance between the corona discharge electrode K and the target electrode M is increased, to maintain a constant ion current between the electrodes, the voltage coupled to the two electrodes must be increased from the DC source 3. Consequently, it is advantageous for the present invention to use a potential difference between the K-discharge electrode K and the target electrode M that is larger than hitherto used, for example, in electrostatic filters or types of dust separators used in family houses. It will be appreciated that if the potential of the K-discharge electrode K is increased relative to the environment, the above-mentioned shielding of the K-discharge electrode K is even more necessary. However, increasing the voltage is also burdened by the associated costs, including high-voltage insulation, both for the power source used and the ion-wind device as such, and since there is of course an upper limit to which the voltage can be increased in practice. One effective or advantageous way to reduce these difficulties is to connect the K crown discharge electrode and the target electrode M to polarities opposite to the ground potential.

However, in a further development of the invention, it is possible to substantially increase the distance between the corona discharge electrode K and the target electrode M, and thereby substantially increase the migration distance of the ion current without significantly reducing the ion current between these two electrodes and without increasing the voltage level. by using a so-called. This excitation electrode is placed near the crown discharge electrode K as shown in Figure 7.

By way of example in Figure 7! In this embodiment, the excitation electrode E is a rotationally symmetrical annular electrode material, but at least has a partially electrically conductive inner surface coaxially arranged around the corona discharge electrode K, while in this embodiment the corona discharge electrode K is needle-shaped. With respect to the particular embodiment of the K-corona discharge electrode used in the illustrated embodiment, the target electrode M is cylindrical and coaxially arranged in the airflow conductor 1 and the shielding electrode S is annularly coaxial with the K-corona discharge electrode. Thus, the excitation electrode E is located at a shorter axial distance from the corona discharge electrode K than the target electrode M and, in the illustrated embodiment, is connected to the same terminal of the DC current source 3 as the target electrode M and a large ohmic resistor 6. The excitation electrode E thus assumes a potential which has the same polarity as the target electrode M relative to the corona discharge electrode K. However, the potential difference between the excitation electrode E and the corona discharge electrode K is smaller than the potential difference between the target electrode M and the corona discharge electrode K. The excitation electrode E contributes to creating and maintaining a corona discharge electrode K, even if the distance between the corona discharge electrode K and the target electrode M is increased without simultaneously increasing the voltage of the DC voltage source 3. Only a small portion of the corona discharge ion current from the corona discharge electrode K will pass to the excitation electrode E, while the greater part of this corona discharge current or flow will flow to the target electrode M and facilitate the transport of air through the apparatus.

The effect exerted by the excitation electrode E is illustrated in the diagram in Fig. 8, where curve A 'shows the crown discharge current I as a function of the voltage U between the crown discharge electrode K and the target electrode M when excitation electrode E was not used. As can be seen, there is no corona discharge and hence no corona discharge ion current until the U voltage exceeds a given UT threshold voltage. In contrast, when the excitation electrode E is placed near the corona discharge electrode K, the conditions of curve B occur, namely that the ion current I starts at a constant voltage at a much lower voltage with the constant distance between the corona discharge electrode K and the target electrode M. Only part of this corona discharge ion current flows to the excitation electrode while the remainder flows to the target electrode M.

The excitation electrode E, together with the target electrode M, is thus regarded as a two-part target electrode M, one of which is located axially close to the corona discharge electrode K and serves as the excitation electrode E while the other portion is located at a significant axial distance from said corona discharge electrode. , and M serves as a target electrode for that portion of the corona discharge ion current that generates the driving force for the airflow.

Consequently, an "excitation electrode" may be produced, for example, as shown in FIG. 9, that is, by extending a portion of the target electrode M toward or just beyond the corona discharge electrode K; the target electrode M in this embodiment consists of a plurality of plates which are parallel to each other and are disposed axially in the air flow conduit 1. In this case, the portions of the target electrode M which are axially closest to the corona discharge electrode K act as the excitation electrode E, while the greater part of the corona discharge ion current I flows to the portion of the target electrode M located axially distal to the corona discharge electrode. thus creating the desired ion slice. If the excitation electrode E is so combined with the target electrode M, i.e. if the target electrode M is axially extended so as to be close to the corona discharge electrode, the target electrode M may preferably be made of a high resistance material or a high resistance surface on the inner surface of a layer may be formed while the distal end of the target electrode M is connected to one of the terminals of the DC voltage source 3 from the corona discharge electrode K. The portion of the target electrode M which is axially closest to the corona discharge electrode K acts as an excitation electrode E, which absorbs only a minor portion of the corona discharge ion current. Alternatively, the combined target electrode M and the excitation electrode E are provided by providing the target electrode M with portions extending axially toward and close to the corona discharge electrode K, which exhibit much less electrical conductivity than the corona discharge electrode of the target electrode. the greater part further away from the electrode, which is connected to one of the terminals of the DC power source 3. These low conductivity regions or portions of the target electrode M located axially close to the corona discharge electrode K serve as an excitation electrode E to which only a smaller portion of the total corona discharge current I from the corona discharge electrode K will pass.

The excitation electrode E can be formed and positioned in a number of different ways. An electrode of any shape which is axially close to the corona discharge electrode K and which does not itself produce a corona discharge, and which is connected to the corona discharge electrode K by another terminal of a DC power source 1, is capable of acting as the excitation electrode E. only a small portion of the total corona discharge ion current flows to this excitation electrode E, while the greater part of the corona discharge ion current flows to the target electrode M, so that a shielding electrode S is arranged upstream of the corona discharge electrode and 5, such as the embodiment of the invention shown in Fig. 5, can serve as the excitation electrode E.

The geometry of the excitation electrode E may vary depending on the shape of the corona discharge electrode K. For example, if the corona discharge electrode K is more geometrically separated but electrically connected11

203620Β, including straight, thin, adjacent wires, the excitation electrode E may preferably also include a plurality of geometrically separated but electrically connected electrode elements which are then disposed between the corona discharge electrode K they should be shielded from each other, which is advantageous for such a corona discharge electrode to generate a corona discharge ion current. 10

Fig. 9 schematically illustrates an exemplary embodiment of the present invention having a corona discharge electrode K, a target electrode M, a shield electrode S, and an excitation electrode E. In this embodiment, each electrode comprises a plurality of geometrically separated but electrically connected electrode elements which, for the corona discharge electrode K, comprise straight, thin wires, such as tungsten, while the rest of the electrodes comprise helically shaped wires, such as stainless steel wires.

As all of the foregoing will be apparent, the arrangement of the present invention may be constructed so that all electrodes are contact-protected, i.e., non-contact-protected, so that, for example, 4, 5, 7, 9 and The embodiments shown in Fig. 10, in which the target electrode M is grounded and the corona discharge electrode K and the shield electrode S, preferably the excitation electrode E, are also connected to higher potentials, may be provided by disabling the air flow conduit 1, that the shielding electrode S is constructed in such a way as to effectively prevent the ion current from the corona discharge electrode K from traveling in a direction other than to the target electrode M.

Although the design according to the invention provides quite satisfactory operation even if there is no air flow conduit 1 around the electrodes in any form, it is desirable in many cases to use such a conduit, for example for psychological reasons or because such conduction through the equipment. In many cases, the use of a duct is unavoidable, for example, when the device is to be located within a vent duct of a venting system or in other cases where the airflow generated by the device is to be vented from a specific location or location. However, the presence of such an air flow conduit, which includes the electrode system 50 and whose walls are, of course, made of electrical insulating material, can lead to annoying problems. As discussed above with reference to Figure 6, an excessive electrical surface charge appears on the inner wall surface of such a conductor. Similar over-surface charges may also occur on portions of the wire located between the corona discharge electrode K and the target electrode M and will influence the desired ion flux from the corona discharge electrode K towards the target electrode M so that the air flow 1 The pipeline tends to eliminate or limit the ionic current to the center area of the cross-section of the pipeline, which results in the air flow 65 being unevenly distributed along the pipeline width, thereby reducing the flow of air passing through it. This problem is greatly exacerbated by voltage changes in the power supply through the aforementioned voltage source at the K-crown discharge electrode and at the target electrode M. The periodic increase in voltage results in a periodically increasing surface charge increase, and these charges are maintained after thereby causing a strong reduction in the corona discharge current and, consequently, in the airflow through the unit. The disadvantages of this phenomenon can be overcome, or at least greatly reduced, by stabilizing the voltage supplied by the voltage source, a measure which is not particularly relevant in other respects to the type of equipment in question. Also, the given voltage of the electrodes can provide a solution and short interruptions at equal intervals. The excess surface charge present on the inner surface of the flow conduit 1 is eliminated relatively quickly if the power supply is interrupted and thus the electric space disappears. However, the excess electric charge present on the first surface of the electrically insulating tube wall poses an additional and surprisingly serious problem. It has been found that by touching the inner surface of the insulating tube wall even for a short period of time, the corona discharge flow is completely interrupted and does not re-establish itself automatically, even after a long period of time after touching the surface. Therefore, a solution to this problem also needs to be found. j

One possible solution to the problem is to apply an electrically conductive layer to the outer surface of the insulating wall of the air flow conduit 1 and to ground this layer. However, this solution would provide high capacity to the target electrode M located near the wall of the air flow conduit 1 or directly on the inner surface of this wall, which - as

mentioned above - would not be desirable from the point of view of contact safety of the target M electrode.

However, it has been found that the problem can be avoided by increasing the cross-sectional dimensions of the air flow conduit 1 to a size substantially greater than the area surrounded by the target electrode M so that the target electrode M is spaced substantially apart. from the inner surface of the air flow duct. Such an embodiment is shown schematically in FIG. 5 below. In this embodiment, the outer surface of the air flow conduit 1 is provided with an electrically conductive layer 10 which is earthed. In this embodiment, one air flow duct g considerably wider than the M target pipe so 1 that the guide walls are M even farther |. célelektródától, which thereby will have a much smaller capacity but in this way the wire S ^f Alai to R corona discharge electrode are located farther away, and thus the additional charges on the insulated conductor j will have a much less disturbing effect on the K crown discharge electrode

Corona discharge current to M target electrode. Said increase in cross-sectional size of the air flow conduit 1 relative to the cross-sectional dimensions of the target electrode M was found not to adversely affect the amount of air transported through the apparatus, and indeed this transport increased with a constant corona discharge current. A11. In the embodiment shown in FIG. 3A, the center point of the DC power source 3 is grounded so that the target electrode M and the corona discharge electrode K are polar opposite to earth, thereby reducing the total required high voltage level, thus eliminating the need for high voltage isolation of the apparatus. as well as the need for shielding of the K crown discharge electrode as discussed above.

Since high voltage is applied to the shielding electrode S, the corona discharge electrode K, and the target electrode M in the present case, each of said electrodes is connected to a DC resistor 3 via a high resistor 8 to limit the short-circuit current when the electrodes touch. In addition, both the target electrode M and the shielding electrode S are preferably made of high-resistance material in order to limit the capacitive discharge current generated upon contact.

In one embodiment, it is advantageous to choose the cross-sectional dimensions of the air flow conduit 1 such that the distance between the conduit wall and the corona discharge electrode K is equal to half the distance between the corona discharge electrode and the target electrode. distance is about 50% of the cross-sectional size of the target electrode assembly M.

The adverse effects caused by the excess charge present on the inner wall surface of the air flow conduit 1 can also be reduced by the use of an excitation electrode E, the function of which has already been described, consisting of an electrical conductive layer 10 applied to the inner wall of the available. As will be appreciated, the presence of a single excitation electrode E on the inner wall surface of the air flow conduit 1 will not produce excess charge. In this respect, if the cross-sectional dimensions of the airflow conduit 1 are enlarged to such an extent that the target electrode M is located at a significant distance from the airflow conduit 1 wall as shown in FIG. 11 above, the excitation electrode E is mounted on the inner surface of the very surprisingly, it can be extended upstream of the target electrode M in the direction of airflow. In fact, in this particular case, an electrically conductive layer 10 may be applied to the inner surface of the wall of the air flow conduit 1, which means that it may extend even upstream of the corona discharge electrode. One embodiment of a cue is shown schematically in FIG.

Accordingly, in the embodiment shown in Fig. 12, the airflow conductor wall 1 is presumably made of a non-volatile insulating material and its inner surface is provided with a highly conductive coating bound to ground potential and serving as the excitation electrode E adjacent to the corona discharge electrode. The cross-sectional dimensions of the air flow conduit 1 are such that the target electrode M, which is framed and is parallel to the wall of the air flow conduit 1, is substantially spaced from the inner surface of said conduit wall and is substantially insulated on the inner surface of the conduit wall from the E conductive coating. Several shielding electrodes S would be disposed upstream of the corona discharge electrode K, for example in the form of ordinary rods. The center point of the two series-connected DC power supplies 3 is grounded, so that the corona discharge electrode K and the target electrode M have opposite polarity to the earth, which has the above-mentioned advantages. The electrodes are also connected to a dc voltage source 3 through a high value 8 to limit the short circuit current.

It will be appreciated that in this embodiment of the apparatus, there will be no excess surface charge on the inner surface of the conductor, and therefore the apparatus will not be burdened by the problems arising from the presence of said surface charge excess. This embodiment of the device according to the invention has been found to provide extremely satisfactory air supply. All. The same conditions as described in FIG. 12 for the dimensioning of the air flow conduit 1 may also be applied to the embodiment of FIG.

It will be appreciated that since the apparatus of Fig. 12 has the possibility of providing the inner surface of the wall of the air flow conduit 1 with a conductive, grounded coating over the entire length of the conduit, there is no obstacle to the conduit wall being exclusively conductive material, which of course greatly simplifies manufacturing and provides other valuable benefits. It is thus possible to coat the inner surface of the conduit at least a portion of its length with a chemical adsorbent or absorbent material, such as a carbon filter, which removes gaseous contaminants such as odors and nitrogen formed by corona discharge from the air by adsorption or absorption. oxides. For the same purpose, it is also possible to form a thin liquid flue, such as water or a chemically active liquid, along the inner surface of the air flow duct. The wall of the air flow conduit 1 may be heated or cooled by suitable means, such as circulation of water, to heat or cool the dried air. All this is made possible by the fact that the wall of the air flow conduit 1 is extremely conductive and grounded.

In embodiments of the apparatus according to the invention in which the electrodes are located in an airflow conduit 1, it has been found advantageous to use a single corona discharge electrode K with a central arrangement since a fly mode allows for maximum distance between the conductor wall and the corona discharge electrode. at the same time, that is to say, the least possible disturbance of the corona discharge electrode K caused by the conductor wall. Alternatively, however, two K crown discharge electrodes which a

-13GB 203620Β are symmetrically positioned on one side of the symmetry plane. In this arrangement, each electrode acts only on one side of the wire and both electrodes operate under mutually identical conditions. 5 However, this does not apply if more than two electrodes are installed in the wire. In embodiments where two corona discharge electrodes K are disposed symmetrically in the air flow conduit 1, it may be advantageous to have two target electrodes M arranged side by side, in the same symmetrical relationship, in this respect as a common electrical electrode. they have a leading wall.

A12. In the embodiment shown in Fig. 15, it is shown that the coating or layer forming the electrically conductive and grounded excitation electrode E on the inside of the insulating air flow conduit 1 need not protrude from the corona discharge electrode in the opposite direction to the air flow; The surplus charge on the conductor wall from the corona discharge electrode K in the upstream direction of air flow contributes to the required shielding of the corona discharge electrode K. 25

A further problem affecting the total airflow through this type of apparatus occurs when the corona discharge electrode K is configured to consist of a wire that crosses through the airflow and its two ends are connected to electrically insulated circuits. The same problem can occur with another type of electrode that crosses through the air stream and connects its two ends to electrically insulated joints. The same problem may occur with other types of electrodes that extend through the air stream 35. In this regard, it has been found that the corona discharge electrode K provides a much stronger corona discharge current per unit length in the middle region of the air flow path than at the ends of the electrode. This appears to be due to the shielding effect of the electrode connections and the conductor wall at each end of the electrode, when the apparatus includes an air flow conduit 1. At low corona discharge currents, both ends of the K corona discharge electrode 45 may be "extinguished" or bypassed. This results in an uneven distribution of the ion flow and, consequently, an uneven distribution of the air flow path across the flow cross section.

If the apparatus comprises an airflow conduit 1 surrounding the electrodes, it has been found that, in cross section, portions of the airflow conduit 1 located at opposite ends of the corona discharge electrode K produce an airflow that is intended 55 flow direction. This phenomenon can severely degrade or even completely eliminate air transport through the unit.

However, according to another embodiment of the invention, this problem can be solved by giving a special shape to the target electrode M 60 and / or the excitation electrode E. An exemplary embodiment of the target electrode M, which is advantageously designed in this latter aspect, is schematically illustrated in Figure 13, which has a narrow, rectangular cross section of the air flow conduit 1 of the apparatus 65 of the present invention. A wire-like corona discharge electrode K is disposed between the two short walls of the air flow conduit 1. The target electrode M is a conductive layer or coating formed on the inner surface of said conductor wall, such that, when viewed in the axial direction, the conductor is closer to the end of the corona discharge electrode K than in its central region in the direction of the diagonal of the conductor. For example, the axial distance between the target electrode M and the corona discharge electrode K in the center region of the latter should be 60 mm, while its corresponding axial distance from the target electrode to the opposite end of the corona discharge electrode is only 40 mm. A target electrode M formed in this manner eliminates the problem previously disclosed and maintains a substantially uniform corona discharge current distribution along the entire length of the corona discharge electrode.

The same result can be obtained if the excitation electrode E positioned between the corona discharge electrode K and the target electrode M is formed as described with reference to bar 13 for the target electrode M. In this case, the target electrode M may be formed either as shown in Figure 13 or in a normal manner, such that its axial distance from the corona discharge electrode K is the same at all points. A satisfactory result can also be obtained by means of excitation E electrodes which are located only near both end portions of the K corona discharge electrode. However, the most basic feature is that the target electrode M and / or the excitation electrode E or electrodes E are configured such that the airflow path through the corona discharge electrode K provides substantially the same amount of corona discharge current per unit length over the entire length of the corona electrode. .

The target electrode M and excitation electrode E of the form described with reference to Fig. 12 can also be advantageously used in apparatus where the electrodes are not surrounded by an air flow conduit 1, since the target electrode M and excitation electrode E thus formed allow for a more even distribution of corona discharge current. along the entire length of the electrode.

The embodiment of the apparatus of the invention shown in Figure 10 has been used in practice for experimental purposes. In this experimental apparatus, the distance between the plane of the shielding electrode S and the plane of the corona discharge electrode K is 12 mm, while the distance between the corona discharge electrode K and the target electrode M is 85 nun. The mutual distance between the wire-like electrode elements used in the corona discharge electrode is 50 mm, and the electrode element of the excitation electrode E is in the same plane as the electrode elements of the corona discharge electrode K. The different electrodes were connected to the voltages shown in the drawing. The airflow line 1 has a 35 x 22 cm cross section and the grounded protective grille G is placed at the thread of the airflow line 1 on-board. When this equipment was placed freely on a table, it provided an air flow rate of 0.5 m / s. The total corona discharge current from the K corona discharge electrode is approx. 50 μΑ, of which approx. 40 μΑ reached the target M electrode. An airflow rate of about 0.5 m / s was achieved with an energy consumption of 6-6W per m ^{2 of} airflow line 1. The energy required to achieve an airflow velocity of the same magnitude in a similar apparatus without, however, a shielding electrode S and an excitation electrode E, with the same voltage at the corona discharge electrode K, is approx. 100 W / m. In this case, the distance between the corona discharge electrode K and the target electrode M is approx. 50 mm, 100 mm between the corona discharge electrode K and the protective grille G at the inlet of the air flow conduit 1. In this embodiment of the device according to the invention, the distance of the protective grid G from the corona discharge electrode K did not significantly influence the efficiency of the device.

The air flow through the apparatus or device of the present invention can be further enhanced by placing a plurality of electrode groups each having a corona discharge electrode, a target electrode, a shielding electrode, and preferably an excitation electrode, and the groups are sequentially disposed in the same air stream. Placing a shield electrode in front of each corona discharge electrode, as described above, effectively prevents undesirable and damaging ion flow in the opposite direction to the air flow, which flow is unavoidable in such cascade arrangement devices.

The unit provides extremely efficient air transport, but with a relatively simple design. In addition, the device according to the invention is relatively inexpensive and small in size and light in weight. The power consumption of this unit is also low and completely silent.

When using an air transport device according to the invention in combination with an electrostatic filter device, the target electrode in the air transport device can be disposed so as to simultaneously form part of the dust separating surfaces of the electrostatic filter device, which serves to known in a capacitor separator. If the target electrode acts as a dust-removing surface for the impurities carried by the air flowing through the apparatus, the target electrode is preferably configured to permit their regular removal for replacement or cleaning if the electrode is already excessively entrained in the debris. It can be seen that this can be done on a regular basis in the absence of an air flow conduit surrounding the electrodes. In this context, it may also be contemplated that the target electrode is formed from a tape reel from a storage drum or is passed through a cleaning device when a portion of the tape material used as a target electrode is contaminated by condensed impurities.

Claims (26)

PATENT CLAIMS An air conveying device by means of an electric ion beam comprising at least one corona discharge electrode (K) and at least one target electrode (M), which allows air passing through the apparatus and is spaced from the corona discharge electrode (K) in the desired air flow direction. , further comprising a DC voltage source (3) having one terminal - terminal - to the corona discharge electrode (K) and the other terminal - a terminal - to the target electrode (M) and the structure of the corona discharge electrode (K) and DC The voltage between the terminals of the power supply (3) is such that a corona discharge generating air ions is produced on the corona discharge electrode (K), characterized in that the corona discharge electrode (K) is shielded by a shielding electrode (S) from the air flow direction. y the product of the ionic current generated in the opposite direction to the air flow and the migration path of the ion current from the corona discharge electrode (K) is practically zero, but in each case much less than the ionic current traveling from the corona discharge electrode (K) furthermore, the distance between the corona discharge electrode (K) and the portion of the target electrode (M) which receives the majority of the ion current is at least 50 mm, but preferably at least 80 mm. Apparatus according to claim 1, characterized in that the electrically conductive shield electrode (S) is located upstream of the corona discharge electrode (K) and has the same polarity as the target electrode (S), mini is the potential of the corona discharge electrode (K). Apparatus according to claim 1, characterized in that the shielding electrode (S) is electrically connected to the corona discharge electrode (K). Apparatus according to claim 1, characterized in that at least the corona discharge electrode (K) is arranged in an air flow conduit (1) having walls made of dielectric material and upstream of the corona discharge electrode (K) in order to achieve shielding effect. extends at a distance at least equal to the distance between the corona discharge electrode (K) and the target electrode (M), preferably 1.5 times. Apparatus according to Claim 1, characterized in that the air flow duct (1) is provided with partitions (7) made of dielectric material upstream of the corona discharge electrode (K) and which extend along the air flow duct (1). they are substantially parallel. The apparatus of claim 1, wherein: 203620Β having an excitation electrode (E) disposed near the corona discharge electrode (K) at a distance less than the target electrode (M) and that the excitation electrode (E) is connected to the corona discharge electrode 5 (K) is connected to a potential with the same polarity as the potential of the target electrode (M) and the portion of the total ion current from the corona discharge electrode (K) that passes to the excitation electrode (E) is substantially less than this total ion current. to the target electrode (M). Apparatus according to claim 6, characterized in that the potential difference between the excitation electrode (E) and the corona discharge electrode (K) is less than the potential difference between the target electrode (M) and the corona discharge electrode (K). Device according to claim 7, characterized in that the excitation electrode (E) is connected to a terminal of a DC voltage source (3), which is connected to the target electrode (M) via a high-value resistor (6). Apparatus according to claim 1, characterized in that the portion of the target electrode (M) proximal to the direction of the corona discharge electrode (K) and serving as the excitation electrode (E) extends axially to the corona discharge electrode (K), the target electrode (M) its electrically conductive material has a high specific resistance and the portion of the target electrode (M) farthest from the corona discharge electrode (K) is connected to one of the terminals of a DC voltage source (3). Apparatus according to claim 1, characterized in that the target electrode (M) is electrically conductive and has portions serving as an excitation electrode (E) at the axial end of the corona discharge electrode (K). extending towards and close to the corona discharge electrode (K), which has a substantially smaller electrically conductive area than the greater portion of the target electrode (M) substantially axially spaced from the corona discharge electrode (K), wherein the greater portion is a DC voltage source ) is connected to one of the terminals. 45 Device according to claim 1, characterized in that the target electrode (M) and the optional excitation electrode (E) comprise electrically conductive surfaces which are parallel to the direction of air flow and surround the air flow path. 50 Apparatus according to claim 1, characterized in that the target electrode (M) and optionally the excitation electrode (E) and the shielding electrode (S) are located in the air flow conduit (1) and the target electrode (M) it comprises electrically conductive surfaces on the wall of the air flow conduit (1). Apparatus according to claim 1, characterized in that the corona discharge electrode (K), the target electrode (M) and the shielding electrode (S) are located on the air flow conductor (1), the target electrode (M) it has electrically conductive surfaces which are parallel to, but spaced apart from, the wall of the air flow conduit (1), and that the wall of the air conduit (1) is electrically insulating and has a grounded, electrically conductive surface disposed thereon (10). Apparatus according to claim 1, characterized in that the corona discharge electrode (K), the target electrode (M) and the shielding electrode (S) are located in the air flow duct (1), the wall of the air flow duct (1). having at least one electrically conductive inner surface, preferably earthed, and electrically conducting the target electrode (M) | conductive surfaces which are parallel to but substantially from the wall of the air flow conduit (1); they are spaced apart inward, and the target electrode (M) and the corona discharge electrode (K) are connected to a potential of opposite polarity to earth. ; Apparatus according to claim 14, characterized in that the air flow conduit (1) is electrically conductive in its entirety. Apparatus according to claim 14, characterized in that the wall of the air flow conduit (1) is made of electrically insulating material and has an electrically conductive layer, preferably earthed, on its inner surface, which is axially approximately from the corona discharge electrode (K) and extends from the target electrode (M) to the downstream location. Apparatus according to claim 13, characterized in that the distance between the wall of the air flow duct (1) and the nearest surface of the target electrode (M) corresponds to approximately 50% of the cross-sectional area of the target electrode (M). Apparatus according to claim 14, characterized in that at least a portion of the inner surface of the air flow conduit (1) is provided with a layer of chemically absorbent material. Apparatus according to claim 14, characterized in that at least a portion of the inner surface of the air flow conduit (1) is wetted with water or a chemically active liquid. 20. The apparatus of claim 14, wherein the temperature of the air flow duct wall is controlled. Apparatus according to claim 1, characterized in that the target electrode (M), the corona discharge electrode (K) and the shield electrode (S) have higher potentials relative to earth and resistors (8,9) for the DC power source (3). are connected, the short-circuit current through resistors (8,9) shall not exceed 300 μΑ in the event of earthing of either the target electrode (M), the corona discharge electrode (K), or the shield electrode (S). Apparatus according to claim 1, characterized in that the target electrode (M), the corona discharge electrode (K) and the shield electrode (S) are large! capacities and potentials differ significantly from the earth potential and, if touched, are east | High Capacity Limiting Capacitive Discharge Current? made of resistance material. ; Apparatus according to claim 1, characterized in that the corona discharge electrode (K) and the | the target electrode (M) is bonded to a potential of opposite polarity to earth. . The apparatus of claim 1, further comprising -16HU 203620Β Characterized in that the corona discharge electrode (K) extends diagonally through the air flow, and that the target electrode (M) has an electrically conductive surface surrounding and parallel to said flow path and finally that the corona discharge electrode (K) and the axial distance between the closest edge of the conductive surface of the target electrode (M) at the locations opposite the ends of the corona discharge electrode (K) is less than at the locations opposite the center of the corona discharge electrode (K). Apparatus according to claim 6, characterized in that the corona discharge electrode (K) extends diagonally across the air flow conduit (1) and that the excitation electrode (E) comprises an electrically conductive surface surrounding and with said air flow path. is located parallel to, and finally, the axial distance between the leading edge of the corona discharge electrode (K) and the leading surface of the excitation electrode (E) at locations opposite to the ends of the corona discharge electrode (K) 5 shorter than those located opposite the center of the corona discharge electrode (K). Apparatus according to claim 6, characterized in that the corona discharge electrode (K) extends diagonally across the air flow conduit (1) and that the excitation electrode (E) comprises an electrically conductive surface parallel to the air flow path, finally, the electrically conductive layers forming the excitation electrode (E) are substantially disposed axially with respect to the ends of the corona discharge electrode (K).