EP3271077B1 - Device and method for separating off contaminants - Google Patents

Description

The present invention relates to a device for separating liquid and / or particulate contaminants from a gas flow, in the between at least one first electrode acting as the counter electrode and at least one second electrode acting as an emission electrode and an electrode end directed towards the first electrode comprises, a flow path of the gas flow runs and a DC voltage exceeding the breakdown voltage can be applied between the first electrode and the second electrode to form a stable low-energy plasma, and a method for operating such a device.

Such generic plasma separators for separating impurities from a gas flow, in particular blow-by gases from a motor vehicle, are known from the prior art. For example the DE 10 2011 053 578 A1 discloses a generic device.

In Figure 1 the basic structure of such a device is shown. It shows Figure 1 a schematic cross-sectional view of FIG DE 10 2011 053 578 A1 known device.

In Figure 2 FIG. 3 is a schematic cross-sectional view of portion A1 of FIG Figure 1 shown.

The separation device 1 has an inlet line 3 and an outlet line 5. In particular, a gas flow 7, such as a blow-by gas flow, is introduced into the separation device 1 through the inlet line 3. The gas stream 7 contains in particular impurities such as solid and liquid particles, in particular oil particles. Inside the separator 1 is a first electrode in the form of a counter electrode 9 and a plurality of second electrodes in the form of emission electrodes 11 are arranged.

The gas stream 7 is guided through the separating device 1 essentially perpendicular to a normal direction N of the counter electrode 9. By means of electrical connections 13, a direct voltage is applied to the emission electrodes 11 which is higher than a breakdown voltage, in particular corresponds to at least 1.2 times the breakdown voltage. The direct voltage applied in this way has the effect that a low-energy plasma is ignited or formed between the emission electrodes 11 and the counter electrode 9. A current strength applied to the connections 13 is adapted in particular as a function of the flow velocity of the gas flow 7 through the separating device 1, but also as a function of other parameters.

The plasma formed between the emission electrode 11 and the counter electrode 9 has the effect that some of the impurities in the gas flow 7 are accelerated in the direction of the counter electrode 9. The impurities then accumulating in the area of the counter electrode 9 are fed to a collecting space 15 and from there fed to a discharge line (not shown).

In order to prevent the gas flow 7 and thus the impurities contained therein from entering an area between the emission electrodes 11, provision is made for partition elements 17 to be provided in an intermediate space between the emission electrodes 11. Both the bulkhead elements 17 and the emission electrodes 11 are attached at least indirectly to a carrier element 19, which in particular comprises an insulating and / or ceramic material. The emission electrodes 11 are fastened indirectly via a thermoset body 21 on which high-resistance resistors are arranged, by means of which the emission electrodes 11 are connected to the connections 13.

The ones in the DE 10 2011 053 578 A1 The device described has basically proven itself. However, it has been shown that the long-term stability and quality of the low-energy plasma generated in the device can be improved. It has been shown, in particular, that an ion wind arises in an area adjacent to the plasma or plasma cone which is forming, which leads to impurities in part in the direction of the emission electrode or the carrier element are accelerated. These particles, in particular oil droplets, can then accumulate in the area of the carrier element or the thermoset body 21. There they can agglomerate and, due to the force of gravity, flow along the thermoset body or the emission electrodes to the ends of the emission electrode facing the counter electrode. Under unfavorable conditions, this can lead to the particles flowing in the end area of the emission electrode that faces the counter electrode, the plasma being created in this area and carbonizing there due to the temperatures prevailing there and being deposited on the electrode end. This in turn can lead to a change in resistance if the deposit is conductive, to a decrease in resistance, and, if the deposit is insulating, to an increase in resistance, so that no stable low-energy plasma then forms at the corresponding electrode.

It is therefore the object of the present invention to further develop the generic device in such a way that the disadvantages of the prior art are overcome, in particular an improved longevity of the separation device is achieved. In addition, an improved method for operating a generic device is to be provided that likewise overcomes the disadvantages known from the prior art.

This object is achieved by means of a device according to claim 1. The second electrode extends essentially along a first axis in a first direction, and the first electrode has at least one plateau region which is arranged opposite the second electrode and extends in at least some regions a first plane extending essentially perpendicular to the first direction.

It is particularly preferred that the plateau area is arranged coaxially to the second electrode and / or the flow path runs essentially between the second electrode and the plateau area.

The invention also proposes that the plateau area, at least in some areas, in particular in the edge area, have a surface that is curved in the direction of the second electrode and / or against the first direction.

Furthermore, the invention provides that the plateau region is arranged at a distance from a base level of the first electrode in the direction of the second electrode.

In particular embodiments, it is preferred that a plurality of second electrodes are present and the first electrode has a plurality of plateau areas, each second electrode being assigned a respective plateau area.

A device according to the invention is characterized in that the plateau area is connected to the base level by means of an in particular electrically conductive spacer element which extends counter to the first direction.

In the aforementioned embodiment, it is particularly preferred that the spacer element runs coaxially to the first axis or the spacer element at a distance from the first axis, preferably at least partially parallel to the first axis and the plateau region by means of at least one, preferably essentially perpendicular to the first direction and / or is connected to the spacer element running along the first plane.

The invention also proposes that the first electrode has an essentially C-shaped cross section, at least in some areas, in particular the C-shape is formed by the base level, the spacer element, the connecting element and the plateau area.

In the aforementioned embodiments, it is particularly preferred that the plateau area, the spacer element, the base level and / or the connecting element are at least partially formed in one piece.

It is further preferred that the plateau areas are connected by means of at least one connecting device which extends essentially parallel to the base level and / or has a smaller extent in at least one direction of the first plane compared to the plateau areas.

In the aforementioned embodiment, it is particularly preferred that the plateau areas are arranged in a direction perpendicular to the first axis along a straight line, in particular the connecting devices extend essentially along the straight line and / or a network and / or a matrix is formed by means of the connecting devices, at least one plateau area being arranged at at least one of the intersection points of the connecting devices, the network and / or the matrix extending along the first level extends.

It is further preferred that the plurality of plateau areas is provided by at least one counter-electrode element, preferably at least regionally designed as a stamped sheet metal part.

In the aforementioned embodiment, it is particularly preferred that the plateau areas in the counter electrode element are arranged along a second direction and / or at least two counter electrode elements can be arranged mirror-symmetrically, preferably at least partially interlocking, preferably offset from one another in such a way that the plateau areas of the respective counter electrode elements are offset from one another are arranged along the respective second direction.

Furthermore, it is alternatively proposed for the aforementioned embodiment that the plateau areas and connecting elements are formed by the stamped sheet metal part.

In addition, the device can be characterized by at least one drip element that is in operative connection with the second electrode, by means of which fluid particles of the gas flow moving in the direction and / or along the second electrode can be collected in such a way that the fluid particles detach from the drip element at a distance from the electrode end.

In this embodiment it is particularly preferred that the drip element is at least partially surrounded by at least one inflow element arranged in the area of the second electrode.

It is further proposed that the second electrode encompasses the draining element at least in some areas, wherein by means of the draining element, fluid particles flowing along the second electrode in the direction of the electrode end are spaced apart from the electrode end can be collected in such a way that the fluid particles detach from the second electrode at a distance from the electrode end.

In the aforementioned embodiment, it is particularly preferred that the electrode end and a feed end of the second electrode opposite the electrode end are arranged offset from one another along a first axis that extends in a first direction such that the electrode end is arranged closer to the first electrode, and the drip element is formed at least in some areas by a transition area of the second electrode which is between a first electrode area in which at least one surface area of the second electrode and / or the electrode extends from the feed end in the direction of the electrode end in a direction with a directional component along the first Axis extends, and a second electrode area in which at least one surface area of the second electrode and / or the second electrode extends at least in areas in a direction with a directional component opposite to the first direction, i st.

The invention also proposes that at least one surface area of the second electrode and / or the second electrode extend from the feed end in the direction of the electrode end, in particular following the second electrode area, in a third electrode area in a direction with a directional component along the first Axis extends, preferably such that the drip element is arranged along the first axis above the electrode end.

An embodiment according to the invention can also be characterized in that the drip element consists of at least one turn of the second electrode, at least one bend in the second electrode and / or the inflow element, at least one helical region of the second electrode, at least one bulge on the surface of the second electrode and / or of the inflow element, at least one skirt and / or at least one plate element comprises and / or is formed.

The invention also proposes that the draining element surrounds the second electrode circumferentially, preferably radially symmetrically, the draining element downstream of the Gas flow is arranged and / or the inflow element is arranged upstream of the gas flow.

A device according to the invention can also be characterized in that the drip element is at least partially formed in one piece with the second electrode and / or the inflow element.

In addition, it can be provided that the second electrode, in particular in the area of the electrode end, has at least one taper.

In the aforementioned embodiment, it is particularly preferred that the taper is in the form of at least one tip, at least one ridge and / or at least one edge. Furthermore, the invention proposes that the second electrode is in a plane perpendicular to a main direction of extent, in particular the first direction , has an essentially cylindrical, triangular, square, rectangular and / or polygonal cross-sectional shape, the second electrode, in particular in the region of the electrode end, has an end surface inclined to the main direction of extent, in particular the taper is encompassed by an edge of the end surface.

It is also preferred that the second electrode, in particular in the area of the electrode end, at least in some areas has a hollow area in which the second electrode is hollow, preferably hollow-cylindrical, tubular and / or cone-shaped, preferably the tapering of at least one end edge of the wall of the Hollow area is included, in particular the taper is formed circumferentially on the electrode end.

A device according to the invention according to the third alternative can also be characterized in that the second electrode comprises a carbon material at least in some areas, in particular in the area of the electrode end, and / or the second electrode at least in some areas, in particular in the area of the electrode end, at least one, preferably one, adhesion of particles and / or fluid-reducing coating, in particular a coating comprising titanium nitride, nanosol, at least one nanoparticle Comprehensive material, at least one material forming a surface with a nanostructure and / or chromium nitride.

In addition, it can be provided that between the flow path and the first electrode and / or the flow path and the second electrode, at least one separating element that is essentially impermeable to the gas flow and / or the impurities and is electrically and / or electrostatically permeable, is arranged at least in some areas.

It is particularly preferred that the separating element comprises at least one separating film and / or a separating membrane and / or at least partially comprises polytetrafluoroethylene. Furthermore, it is proposed with the invention that the separating element touches the second electrode, in particular the electrode end, or the first electrode.

A device according to the invention according to the fourth alternative is particularly preferably characterized in that, when the separating element is arranged between the first electrode and the flow path, at least one discharge opening is provided in the separating element, with the discharge opening separated from the gas flow, in particular on the gas flow facing side, the separating element accumulating, contaminants can be discharged into at least one collecting space. According to a fifth alternative, which can be designed in addition or as an alternative to the aforementioned four alternatives, a device according to the invention can be characterized in that the device comprises at least two second electrodes, preferably a plurality of second electrodes, the second electrodes being at least a first carrier element, and at least one discharge device for reducing an electrostatic charge of the carrier element and / or for discharging charge carriers accumulating on a surface of the carrier element is provided at least in the area between the second electrodes.

It is particularly preferred that the second electrodes pass through the carrier element at least in regions and / or the carrier element comprises at least one ceramic material.

In the two aforementioned embodiments, it is proposed that the diverting device comprises at least one diverting element applied at least in some areas to the carrier element and / or embedded at least in some regions in the carrier element, the diverting element preferably at least one, in particular electrically conductive, dissipative coating, at least one, in particular comprising polyamide and / or earthed, conductive fabric, and / or at least one metal band, such as a copper band, and / or the conductive device is designed as a conductive tunnel element.

It is also preferred that the discharge device comprises at least one depression formed at least in certain areas in the carrier element.

In the aforementioned embodiments, it is particularly preferred that the discharge device comprises at least one discharge device arranged in the area between the electrode ends of the second electrodes and the carrier element.

In the aforementioned embodiment, it can be provided that the discharge device comprises at least one conductive grid, at least one conductive foam, at least one shield element which at least partially surrounds the respective second electrode, preferably arched radially outward in the direction of the electrode end, in particular the discharge device on the same electrostatic potential, like the second electrodes.

Furthermore, it is finally proposed with the invention for the device according to the invention that the discharge device, the discharge element, the discharge coating and / or the discharge device extend at least partially along and / or in a first wall and / or second wall that extends at least partially in one direction between the second electrode and the first electrode in a direction along the first axis and / or in the first direction and / or into which at least one inlet opening or one outlet opening opens, and / or along and / or in a third Wall that extends at least partially parallel to the first carrier element, at least partially below the first electrode and / or at least partially on a side of the first electrode facing away from the second electrode.

In addition, a device according to the invention can be characterized in that
the device comprises at least two second electrodes, preferably a plurality of second electrodes, and at least one influencing device for influencing the electrical field formed by the at least two second electrodes can be and / or be arranged at least in regions between the at least two second electrodes.

It is particularly preferred that the influencing device can be arranged and / or arranged essentially at least in regions opposite at least one first electrode, preferably a plurality of first electrodes, and / or a preferably predetermined electrical potential can be and / or be applied.

In the aforementioned embodiment it can be provided that the influencing device is conductively connectable and / or connected to the at least one first electrode, the potential of the first electrode can be and / or applied to the influencing device and / or the influencing device and the discharge device, the discharge device and / or the diverting element are formed jointly at least in some areas.

Furthermore, the invention provides a method for operating a device of the generic type or a device according to the invention, the device being supplied with a liquid and / or particulate impurities having a gas stream, for separating the impurities from the gas stream, the gas stream at least partially along an between at least one first electrode and at least one second electrode is guided and a DC voltage exceeding the breakdown voltage is formed between the first electrode and the second electrode to form a stable low-energy plasma and the method further comprises a cleaning step for cleaning the first electrode and / or the second electrode.

For the method, it is proposed, in particular, that a ground potential be applied to at least one first group of a plurality of second electrodes during the cleaning step or a voltage exceeding the DC voltage and generating a flashover between the first electrode and the second electrodes of the first group is applied, in particular while the DC voltage for forming the low-energy plasma is applied to at least one second group of the second electrodes.

In the aforementioned embodiment, it is particularly preferred that the second electrodes are assigned alternately to the first group and the second group.

For the method it is conceivable that a mechanical excitation of the first electrode and / or the second electrode is generated in the cleaning step, preferably by means of an ultrasonic oscillation generated by at least one excitation device, with at least one piezoelectric element and / or at least one component of a Internal combustion engine and / or a vibration transmission device that is operatively connected to a component of the internal combustion engine for transmitting vibrations is used.

It is also conceivable that the cleaning step comprises the sequential movement of at least two first electrodes and / or two second electrodes by means of a cleaning element, such as at least one brush.

The above-mentioned object with regard to the device is achieved in that the second electrode extends essentially along a first axis in a first direction and the first electrode is arranged at least one opposite to the second electrode and is at least partially perpendicular to the first direction extending first plane having plateau region.

In addition, in order to achieve the object according to the invention, at least one drip element which is in operative connection with the second electrode and by means of which fluid particles of the gas flow moving in the direction and / or along the second electrode can be collected in such a way that the fluid particles are spaced apart from the electrode end from the Dissolve drip element, suggested.

For the device according to the invention, in order to achieve the object according to the invention, it is proposed that the second electrode, in particular in the region of the electrode end, have at least one taper.

The invention further proposes that between the flow path and the first electrode and / or the flow path and the second electrode at least one separating element, which is essentially impermeable to the gas flow and / or the impurities and is electrically and / or electrostatically permeable, is arranged at least in some areas. A separating element is understood here, in particular a basically closed and / or at least partially permeable separating element for electrodes, such as a separating film and / or separating membrane. It is further proposed that the device comprises at least two second electrodes, preferably a plurality of second electrodes, the second electrodes extending from at least one first carrier element and at least one discharge device for reducing an electrostatic charge of the carrier element at least in the area between the second Electrodes is provided.

It is further proposed that the discharge device can also extend into other (wall) areas, in particular into a first and / or second wall or side wall and / or a third or bottom wall. In this way the formation of a "Faraday cage" is possible. The discharge device is preferably electrically conductive at least on its surface and / or completely.

It is further proposed that the device comprises at least two second electrodes, preferably a plurality of second electrodes, and at least one influencing device for influencing the by the at least two Second electrodes formed electrical fields is provided at least in areas between the at least two second electrodes. An influencing device is understood to mean, in particular, sheet metal strips or solid bodies made of metal. Finally, the invention provides a method for operating a device according to the invention or a device of the generic type, wherein the device is supplied with a liquid and / or particulate impurities having a gas stream, for separating the impurities from the gas stream, the gas stream at least partially along a between at least one first electrode and at least one second electrode is guided and a DC voltage exceeding the breakdown voltage is formed between the first electrode and the second electrode to form a stable low-energy plasma, and the method further comprises a cleaning step for cleaning the first electrode and / or the second electrode.

The invention is thus based on the surprising finding that comparatively simple structural or structural adaptations of the generic device can significantly increase its long-term stability. This means that the device can also be used, for example, to remove oil residues from fresh air that is supplied to a passenger cabin of an aircraft and, for example, taken from a turbine. Thus, the device can effectively avoid an aerotoxic syndrome.

In the approach it is proposed that a special design of the counter electrode be selected. In contrast to the counter-electrode known from the prior art, in which an essentially flat counter-electrode has been proposed, the approach provides that a separate counter-area of the counter-electrode is assigned to each individual emission electrode. This region of the counter electrode, referred to as the plateau region, is spaced apart from a base level of the counter electrode, in particular by a spacer element. The plateau areas protrude from the base level, so to speak, in the form of mushroom elements. It can be provided that the spacer element is arranged coaxially to the emission electrode or a longitudinal axis of the spacer element extends at least in some areas in a shift in the direction of extent, in particular the first direction and / or along the first axis. This structure of the The effect of the counter electrode is that particles that collect on the counter electrode, in particular oil droplets, automatically flow away from the plateau area so that they can then flow away via the base level into the collecting space.

In particular, if the plateau area has a curvature at least in some areas, the flow of the particles is supported. The curvature can only be formed in an edge area of the otherwise planar plateau area. Thus, a compromise is reached between the best possible formation of a (wide) plasma cone through the flat area and the best possible removal of particles. The curvature has the effect that when particles flow away from the edge area, particles arranged in the flat plateau area are also “drawn along”, in particular due to the viscosity of a contaminating fluid. The advantage is thus achieved that an accumulation of particles in the area of the counter electrode, in which the plasma is formed, is avoided. It was recognized that an accumulation in this area can lead to undesired charring of the particles and thus to an impairment of the plasma.

In order to simplify the provision of the plateau areas of the counter electrode, it is proposed in a particularly preferred embodiment that a plurality of plateau areas be formed by a single counter electrode element. This counter electrode element is preferably designed as a stamped sheet metal part and has a C-shaped or "lying" U-shaped cross section. The lower transverse element of the counter electrode element forms the base level, from which the spacer element extends essentially vertically upwards. A spoon-shaped element then protrudes perpendicular to the spacer element, which represents a connecting element which, so to speak, forms the "handle" of the spoon, and the plateau area, which forms the "scoop area" of the spoon.

The connecting element creates an electrical connection between the spacer element and the plateau area and at the same time holds the plateau area mechanically. This enables a multiplicity of plateau areas, which are arranged next to one another in a second direction, to be formed on the spacer element. In particular if two of these counter-electrode elements are arranged mirror-symmetrically to one another and are arranged offset from one another in the second direction, a plurality of plateau areas arranged offset to one another can thus be provided in the area of the counter-electrodes. The counter-electrode elements can be designed to be completely mirror-symmetrical. Alternatively, especially if the base levels are arranged overlapping at least in some areas, the counter-electrode elements differ in the length of the spacer elements in such a way that the plateau areas of the counter-electrodes are arranged at the same height or at the same distance from the second electrodes.

In a further embodiment it can be provided that the plateau areas are connected to one another by connecting devices. In this case, the connecting devices in the first plane have a smaller extent than the plateau regions, at least in one direction. In this way it is possible to provide a chain or a matrix or a network of plateau areas which are arranged above a base level. It is thus possible to dispense with spacing elements for each individual plateau area, in particular the plateau areas and the connecting devices are "spanned" at the respective end points above the base level. Due to the omission of the spacer elements, better drainage of the impurities below the plateau areas is possible, since an essentially open space can be provided below the plateau areas.

The use of these counter-electrode elements enables the respective plateau area to be assigned to each emission electrode, so that a plasma cone can be formed in the area of each emission electrode at a predefined location and in a predefined area, with the plasma cones also being formed due to the relative arrangement of the individual plateau areas a fixed relative position to each other. Due to the improved outflow of the particles from the plateau area, in particular due to the curvature, at least in the edge area, the plasma cones are also stabilized. In this way, the particles can flow away from each of the plateau areas in a barrier-free manner, so that agglomeration of particles, as can occur with counter-electrodes known from the prior art, is avoided.

In addition, it is proposed that a drip element be formed in the area of the emission electrode. This drip element can in particular be designed in one piece with the emission electrode or be implemented as a separate component which is arranged independently of the emission electrode or is connected to it.

The use of such a drip element is based on the knowledge that in the area of the plasma cone, in particular adjacent or also in the plasma cone, an ion wind is generated, which leads to impurities in the gas flow, which have been charged by passage through preceding plasma areas, in a direction towards the emission electrode to be accelerated. As a result, impurities, in particular fluid droplets, can accumulate above the plasma cone in the area of the carrier element or thermoset body. The impurities are basically harmless at these points. The arrangement of the emission electrodes on the carrier element can also take place in that the emission electrodes go through a carrier element in the form of a perforated plate through the holes of the perforated plate and the electrode tips protrude from these. The carrier element can also comprise other or additional materials than or in addition to thermoset, such as a ceramic material.

However, in order to prevent deposits that are conductive, such as condensate, water or soot particles, from accumulating in this area, thermally insulating materials are preferably used as wall materials. These lead in particular to the fact that after the separator has been idle there is less tendency for condensate liquid to accumulate on the surface of the housing.

However, over a longer period of operation of the separating device, impurities can agglomerate and then move in the direction of the counter electrode due to the effect of gravity. This is mostly done in such a way that the fluid droplets run down the thermoset body or the perforated plate and then flow along the emission electrode in the direction of the electrode tip or the electrode end.

The drip element according to the invention now ensures that agglomerating fluid droplets flow at a distance from the electrode tip in the direction of the counter electrode and drip off outside the emission electrode in the direction of the counter electrode or are entrained again by the gas flow.

As already described above, it can be provided that the emission electrode has a turn such that a first area of the emission electrode initially extends in the direction of the counter electrode, but is followed by a second area in which the emission electrode extends away from the counter electrode around itself then to extend again in a third area in the direction of the counter electrode in order to then open into the electrode tip or the electrode end.

This has the effect that liquid particles flowing down the emission electrode initially collect at the lowest point of the turn, but cannot flow to the electrode tip. If the amount of liquid accumulating at the lowest point of the turn reaches a predetermined level, the liquid detaches from the draining element without reaching the electrode tip, in particular without being able to lead to charring of the electrode tip there. Corresponding drip elements can also be designed as umbrella-shaped elements which surround the emission electrode in a bell-shaped manner in order to form corresponding drip elements on the outer edge of the umbrella. It can also be provided that the emission electrode has corresponding bulges on its surface, preferably formed in one piece with the electrode material.

In an alternative embodiment it can be provided that the drip element is designed in that the emission electrode is designed to be hollow in areas, in particular in the area of the electrode end. This leads to an essentially circular drip element being formed at the end of the electrode if the electrode has an essentially cylindrical cross section.

This structure has the result that, if a drop of liquid reaches the end of the electrode, the plasma generation is interrupted in this area in such a way that another area of the cylindrical drip element acts as the starting point for the plasma. This prevents the liquid drop adhering to the drip element is heated by the plasma in such a way that the electrode tip becomes charred. If the liquid drop is then detached due to gravity, the starting point of the plasma cone migrates to a corresponding point along the circular drip element. This also effectively prevents overheating and carbonization of the electrode tip.

In addition, it is proposed that the flow area of the stream be hermetically separated from the areas in which the emission electrode or the counter electrode is arranged. In particular, it is proposed that this separation be carried out between the flow area and the emission electrode. For this purpose, it is proposed that the flow path, in particular in the area of the emission electrode, be limited in the area of the emission electrode by a separating element, such as a film or membrane, which is impermeable to the gas flow or the particles contained therein, i.e. in particular the blow-by gas becomes. In contrast, the separating element is permeable to charge carriers such as electrons. Teflon or polytetrafluoroethylene films have proven to be particularly suitable elements. These offer the advantage that they are electrically permitted, i. H. that the direct voltage applied to the emission electrode can pass through the film into the flow area, so that the low-energy plasma continues to form in the flow area. In other words, electrodes can pass through the separating element. It is particularly preferred that the film is in direct contact with the electrode tips of the emission electrodes. In this way, the best possible formation of the low-energy plasma is ensured with, at the same time, the best possible separation of the electrode area from the gas flow. In particular, this prevents particles located in the gas stream from being able to accumulate on the emission electrode or on adjacent structural elements of the separation device, which, as described above, could lead to contamination and carbonization of the electrodes.

If a corresponding separating element is provided in the area of the counter electrode, it is particularly proposed that the separating element have corresponding drainage openings, through which the contamination can flow at predefined points in a corresponding collecting space.

In addition, it is proposed that additional measures be taken to reduce the acceleration of particles from the gas flow in the direction of the emission electrodes or areas adjacent to them.

In particular, it was recognized that the bulkheads known from the prior art lead to electrostatic charging of the surface in an intermediate area between the emission electrodes, which then leads to contaminants ionized by preceding plasma cones in the direction of these electrostatically charged Surfaces are accelerated in order to be agglomerated there and then to migrate along the emission electrode in the direction of the counter electrode.

Even leaving out the corresponding bulkheads leads to an improvement in the situation. With the invention, however, it is also proposed that corresponding discharge devices are provided in an intermediate area between the emission electrodes or rows of emission electrodes. In the simplest embodiment, a corresponding discharge device is formed by a recess, in particular formed in the carrier element. The resulting spacing of the lowered areas of the depression from the emission electrode results in a reduced electrostatic charge on the surface area of the carrier element. In addition, it is also proposed according to the invention that actively acting discharge elements are arranged in the area of the surface areas arranged between the emission electrodes.

The diverting elements can in particular be an electrically conductive coating which leads to charge carriers that have accumulated in the area of the surface being removed as quickly as possible. This discharge coating can be applied to the corresponding surface or elements embedded in the surface, such as conductive fabric, which in particular comprise polyamide or a metallic material such as copper, can be provided. In particular in the case in which the conductive coating or the conductive fabric is placed on the same electrical potential as the emission electrode prevents the attraction of contaminants ionized in the gas stream.

In particular, when the discharge element extends over the walls which surround the area between the emission electrode and the counter electrode, a space can be formed which acts as a Faraday cage. If the diverting element is connected to ground, surface charges on the walls can flow off directly and thus electrostatic forces of attraction on the impurities, which could cause accumulation on the walls, can be effectively avoided.

The formation of tunnel-like discharge elements leads in particular to an increase in the surface of the counter-electrode. These tunnel elements are preferably arranged alternating with the electrodes.

The tunnel elements can additionally or alternatively comprise a very coarse-meshed conductive grid or conductive bars / threads, which serve to improve the drainage of impurities on the additional counter electrodes (tunnel surface). It can also be provided that a further discharge device is arranged at a distance from the surface. This can be implemented, for example, by a grid that is electrically conductive, the emission electrodes protruding through the discharge device. If the discharge device is connected to the same electrical potential as the emission electrodes or to ground, an attractive effect on particles present in the cooking stream is likewise prevented. By dissipating the electrostatic charge on the corresponding surface, it is prevented that impurities can accumulate and agglomerate in the surface area, which could otherwise lead to the impurities being deposited on the emission electrode and leading to encrustation or burning of impurities there could.

A corresponding discharge device can also be implemented by a shielding element surrounding the emission electrode, which can also serve as a drip element at the same time.

Finally, it is suggested that By statically influencing the electrical field by means of at least one influencing device, the ion winds are guided due to the modified field shape, in particular the plasma cone, in such a way that they no longer have a disadvantageous effect on the blow-by, namely that disadvantageous turbulence of the blow-by no longer occurs. The modification also results in an early separation of the particles, so that they are no longer carried along in the blow-by for as long.

In the device known from the prior art and through tests, it was recognized that the flow behavior of the blow-by due to turbulence in the area of the emission electrodes leads to particles reaching the emission electrode tips, that is to say can lead to contamination. It was also recognized that with a suitable design of the influencing device described above, in particular designed like a tunnel, which can represent a conductive device in the form of a frame element, this influences the electrical field formed by the emission and counter electrode in such a way that the clay winds as a result of the new field Preferably direct the blow-by downwards in the direction of the counter electrode. The ion winds no longer have a disadvantageous effect insofar as particles of the blow-by are no longer transported in the direction of the emission electrodes. As a result, it was observed that disadvantageous turbulence in the blow-by is no longer present, at least can be reduced. A particularly compact and simple structure is obtained if at least one influencing device is formed at least in some areas in one with at least one discharge device and / or at least one discharge element.

In this case, the influencing device is preferably a metallic insert that is connected to the counter-electrode and thus grounded, or in any case is at the same potential as the counter-electrode. The influencing devices lead to a frame at a defined potential being formed around the blow-by flow. Also, when the influencing device is placed on the potential of the counter electrode, the counter electrode area is increased. The shape of the influencing device, in particular a cross-sectional shape in a plane perpendicular to the flow device of the blow-by, can in particular be selected with an essentially C-shaped cross-sectional profile, which is preferably made up of three subsegments, preferably arranged perpendicular to one another, and / or preferably from a substantially vertical arrangement of the Segments with an arc-like connection between the respective sub-segments. The influencing element can also be constructed in the form of at least one continuous arc. The influencing device extends, in particular at least regionally, between at least two second electrodes along the upper wall, and continued downward along the two side walls.

It has been shown that the end faces of the influencing device, i.e. the sides facing the emission electrodes, lead to the shift of the electric field and it is therefore possible in particular to design the influencing devices either from a solid metal body or from sheet metal, for example. It is also sufficient if a conductive surface is formed only on the end face. For example, a main body can therefore be non-conductive and only a coating or a conductive area can be present on the end face. It has also been shown that the positive effect of the influencing device on the behavior of the blow-by through continuous repetition of influencing devices along the flow direction of the blow-by, especially alternating with groups of second electrodes, also on subsequent emission electrodes along the flow direction of the blow -By can be transferred. As a result, as far as possible all electrode tips can be protected from contamination by deposited particles.

Finally, the invention proposes a method for operating a device according to the invention, by means of which the aforementioned disadvantages of the prior art are overcome.

In particular, it is proposed that a cleaning step be carried out during the operation of the separation device. This cleaning can be done in a variety of ways. On the one hand, a group of emission electrodes, in particular a whole row of emission electrodes, can be cleaned during operation by electrically connecting this group of emission electrodes to ground. This has the effect that impurities deposited on the emission electrode are carried away by the gas flow or are drawn to the counter electrode due to a capacitor effect. It is also conceivable that the first group of emission electrodes is supplied with a voltage, by which a flashover of this emission electrode and the counter electrode is generated. This leads to the emission electrode being burned free, ie the impurities arranged on the emission electrode being burned off. In particular, it is further preferred that the individual emission electrodes are alternately subjected to this cleaning step, in particular the emission electrodes are successively supplied to ground or with the free-burning voltage.

It is conceivable that mechanical cleaning of the emission electrodes is carried out. For this purpose, it is proposed that the emission electrodes are set to vibrate, in particular ultrasonic vibration. This can take place in that an ultrasonic vibration is generated by a piezo element or the electrodes are mechanically connected to a vibrating element, in particular a component of an internal combustion engine, and cleaning by dissolving the contamination on the emission electrode is achieved through the vibration excitation.

For example, cleaning can be carried out using a cleaning element, such as a brush, which is guided sequentially over the electrode tips.

Further features and advantages of the invention emerge from the following description, in which preferred embodiments of the invention are explained with reference to schematic drawings.

Figur 1

eine schematische Querschnittansicht einer Abscheidevorrichtung gemäß dem Stand der Technik;

Figur 2

eine Detailansicht der Abscheidevorrichtung der Figur 1 gemäß dem Ausschnitt A1;

Figur 3a

eine schematische Querschnittsansicht eines Gegenelektrodenelements gemäß der Erfindung;

Figur 3b

eine Aufsicht auf das Gegenelektrodenelement der Figur 3a aus Richtung B;

Figur 4a

eine schematische Querschnittsansicht zweier Gegenelektrodenelemente gemäß der Erfindung;

Figur 4b

eine Aufsicht auf die Gegenelektrodenelemente der Figur 4a aus Richtung C;

Figur 4c

eine schematische Aufsicht auf eine Gegenelektrode gemäß einer weiteren Ausführungsform;

Figur 4d

eine Aufsicht auf eine Gegenelektrode gemäß einer weiteren Ausführungsform;

Figuren 5a bis 5d

schematische Darstellungen verschiedener Ausführungsformen einer Emissionselektrode mit jeweiligem Abtropfelement;

Figur 6a

eine schematische Darstellung einer Emissionselektrode mit einem erfindungsgemäßen Anströmelement mit einem Abtropfelement;

Figur 7

eine schematische Querschnittsansicht eine Emissionselektrode gemäß einer weiteren Ausführungsform;

Figur 8

eine schematische Querschnittsansicht einer erfindungsgemäßen Abscheidevorrichtung, in der eine Trennfolie gemäß der Erfindung eingesetzt wird;

Figur 9

eine schematische Querschnittsansicht eines Trägerelements mit einer Ableiteinrichtung;

Figur 10

eine schematische Querschnittsansicht eines alternativen Trägerelements mit einer Ableiteinrichtung;

Figur 11

eine schematische Querschnittsansicht einer erfindungsgemäßen Abscheidevorrichtung unter Verwendung eines Ableitelements in Form eines leitfähigen Gitters;

Figur 12

eine schematische Querschnittsansicht einer weiteren Ausführungsform einer erfindungsgemäßen Vorrichtung zur Durchführung eines erfindungsgemäßen Verfahrens;

Figur 13

eine schematische Querschnittsansicht einer erfindungsgemäßen Beeinflussungsvorrichtung in Form eines metallischen Vollkörpers.

Figur 14

eine schematische Aufsicht auf die im Wechsel angeordneten paarweise Reihen der Emissionselektrode und der Beeinflussungsvorrichtungen;

Figur 15a

eine simulierte Gestalt des elektrischen Feldes in der Umgebung der Emissionselektrode ohne geerdete Stirnseite der Beeinflussungsvorrichtungen;

Figur 15b

eine simulierte Gestalt des elektrischen Feldes in der Umgebung der Emissionselektrode mit geerdete Stirnseite der Beeinflussungsvorrichtungen; und

Figuren 16a bis 16c

eine schematische Darstellungen des Querschnittsprofils in verschiedenen Ausführungformen der Beeinflussungsvorrichtungen.

It shows:

Figure 1

a schematic cross-sectional view of a separation device according to the prior art;

Figure 2

a detailed view of the separation device of Figure 1 according to the section A1;

Figure 3a

a schematic cross-sectional view of a counter electrode element according to the invention;

Figure 3b

a plan view of the counter electrode element of FIG Figure 3a from direction B;

Figure 4a

a schematic cross-sectional view of two counter electrode elements according to the invention;

Figure 4b

a plan view of the counter electrode elements of Figure 4a from direction C;

Figure 4c

a schematic plan view of a counter electrode according to a further embodiment;

Figure 4d

a plan view of a counter electrode according to a further embodiment;

Figures 5a to 5d

schematic representations of different embodiments of an emission electrode with respective drip element;

Figure 6a

a schematic representation of an emission electrode with an inflow element according to the invention with a drip element;

Figure 7

a schematic cross-sectional view of an emission electrode according to a further embodiment;

Figure 8

a schematic cross-sectional view of a separation device according to the invention, in which a release film according to the invention is used;

Figure 9

a schematic cross-sectional view of a carrier element with a discharge device;

Figure 10

a schematic cross-sectional view of an alternative carrier element with a discharge device;

Figure 11

a schematic cross-sectional view of a separation device according to the invention using a discharge element in the form of a conductive grid;

Figure 12

a schematic cross-sectional view of a further embodiment of a device according to the invention for performing a method according to the invention;

Figure 13

a schematic cross-sectional view of an influencing device according to the invention in the form of a metallic solid body.

Figure 14

a schematic plan view of the alternating pairs of rows of the emission electrode and the influencing devices;

Figure 15a

a simulated shape of the electric field in the vicinity of the emission electrode without a grounded end face of the influencing devices;

Figure 15b

a simulated shape of the electric field in the vicinity of the emission electrode with the end face of the influencing devices grounded; and

Figures 16a to 16c

a schematic representation of the cross-sectional profile in different embodiments of the influencing devices.

In Figure 3a a schematic cross-sectional view of a counter electrode element 31 is shown in a schematic cross-sectional view. In Figure 3b FIG. 13 is a plan view of the counter electrode element 31 from direction B in FIG Figure 3a shown.

Like that Figures 3a and 3b As can be seen, the counter electrode element 31 has a multiplicity of plateau regions 33. The plateau regions 33 are arranged coaxially to an emission electrode 11 which extends along an axis X. The plateau areas 33 are connected to a base level 37 by means of spacer elements 35. As previously described and explained below, other configurations for achieving the spacing can also be used be realized. An electrical connection between the plateau region 33 and the spacer element 35 is established via a connection element 39.

How in particular Figure 3a It can be seen that the spacer element 35 does not run coaxially to the axis X but parallel to it. In embodiments that are not shown, it is provided that the spacer element runs coaxially to the axis X, so that the counter-electrode elements are "mushroom-shaped". How beyond Figure 3a It can be seen that the plateau region 33 has a curvature.

In a preferred embodiment, not shown, the curvature is formed in particular in an edge region of the plateau region, while the central region of the plateau region is planar. In this way it is ensured that a stable and as wide as possible plasma cone is formed, but at the same time it is ensured that, in particular liquid, impurities do not accumulate on the plateau area but flow away from it. Due to the viscosity of the impurities, it is achieved that liquid impurities present at the edge of the plateau area "carry away" impurities present in the small area as well.

This drainage of impurities is further supported by the fact that an "ion wind" forms in the area of the plasma cone, both adjacent to it and inside, which leads to these impurities being "blown away" from the plateau area, in particular the flat area .

The plateau region 33 thus ensures that a predefined shape of a plasma cone 41 is formed. In addition, it is ensured that impurities deflected in the direction of the counter-electrode element 31 via the plasma cone 41 can flow off directly from the plateau area 33, in particular cannot accumulate and agglomerate in the plateau area, and thus lead to contamination of the counter-electrodes.

The ones in the Figure 3a The recognizable C-shaped cross-sectional shape of the counter-electrode element 31 allows two counter-electrode elements, as in FIG Figure 4a shown, can be combined with each other. Like the one in particular Figure 4b As can be seen, the counter-electrode elements 31 can be arranged mirror-symmetrically and slightly offset from one another become. This allows the plateau regions 33 of the respective counter-electrode elements 31 to be arranged offset from one another, so that they can each be positioned coaxially with respect to the corresponding emission electrodes 11. Due to the offset arrangement of the counter electrode elements 31, the respective plasma cones 41 can be formed offset from one another, so that an almost closed "plasma wall" is created for the gas flow.

In an alternative embodiment, not shown, it can be provided that the two in Figure 4a The counter electrode elements shown are not completely identical, but rather the spacer elements 35 have different heights. It is thereby achieved that the base levels can be arranged overlapping and at the same time it is ensured that the plateau regions 33 are arranged at the same height. The plateau areas are thus evenly spaced from the emission electrodes and a uniform "plasma wall" / plasma cone can be formed.

In the Figures 4c and 4d alternative embodiments of counter-electrode elements 31 ', 31 "are shown. In each of the figures, schematic top views of the counter-electrode elements 31', 31" are shown. The counter-electrode elements 31 ', 31 "also have plateau regions 33', 33". The plateau regions 33 'of the counter-electrode element 31' are, however, arranged in a "chain-like manner", while the plateau regions 33 "of the counter-electrode element 31" are arranged in a "matrix-like manner". This means that not each individual plateau area 33 ', 33 "is spaced apart from the base level via a spacer element, but rather only plateau areas 33', 33" arranged in the edge area of the counter-electrode elements 31 ', 31 "are spaced apart from the base level via suitable spacer elements. The remaining plateau areas 33 ', 33 "are connected to one another or to the plateau areas 33' arranged at the edge via connecting devices 43 '.

The connecting devices 43 ', 43 "are designed as conductive elements, which, however, have a smaller extent than the plateau regions 33', 33" in at least one spatial direction. It is thus achieved that the plasma cones are essentially formed between the plateau areas 33 ', 33 "and the respective emission electrodes. Because of this connection of the plateau areas 33', 33", they span an otherwise free area between the counter-electrode elements 31 ', 31 "and the Basic level.

The counter-electrode elements 31 ', 31 "can be designed as stamped sheet metal parts. This ensures that the plateau regions 33', 33" are arranged essentially in the same plane and at the same time a structurally simple production of the counter-electrode elements 31 ', 31 "is made possible .

This construction ensures that the essentially barrier-free space below the counter-electrode element 31 ', 31 "simplifies the removal of impurities deposited in the plasma separator. The impurities can also be removed more easily from the counter-electrode is electrically conductively lined and grounded under the counter-electrode elements and thus serves as an additional separation possibility for the impurities that come past the plate area.

In the Figures 5a to 5d different embodiments of emission electrodes 51, 53, 55 and 57 are shown. What these emission electrodes have in common is that they each have a drip element.

For example in Figure 5a it is shown that the emission electrode 51 has at least one bend 59. The bend 59 represents a drip element. The bend 59 divides the emission electrode 51 into different electrode areas. In a first electrode area 61, the emission electrode 51 extends from a feed end 63 along the axis Y. The bend 59 is followed by a second electrode area 65 in which the emission electrode 51 has a directional component that runs counter to the Y axis. A further bend 67 is followed by a third electrode area 69 in which the emission electrode 51 again extends in the direction of the Y axis.

As a result, the electrode end 71, starting from which the plasma cone is formed, is arranged below the drip element 59. If it happens that particles driven by an ion wind, in particular oil particles, collect on the emission electrode 51, in particular the electrode area 61, or flow from the carrier element into the electrode area 61, the liquid droplets collect in the area of the drip element 59 long before they move away from the Loosen emission electrode 51 and move in the direction of the counter electrode, in particular accelerated by the plasma. This in particular prevents the impurities from being able to collect in the area of the electrode end 71 and causing charring there.

In Figure 5b a further embodiment of an emission electrode 53 with a drip element 73 is shown. In the emission electrode 53, the drip element is formed by the lower region of a turn 75. In this embodiment, the electrode end 77 is located upstream of the gas flow, so that after dripping off the dripping element 73, the liquid droplets are prevented from moving again in the direction of the electrode end 77 and being able to be deposited there again.

At the in Figure 5c Emission electrode 55 shown, a drip element 79 is formed by an annular bead in the upper region of emission electrode 55. The drip elements 79 are formed in particular by a bead formed on the surface of the emission electrode 55. In particular, a bead can be formed by a “bead-like casing” which comprises, for example, plastic, ceramic, metal or rubber. In addition or as an alternative, the bead can also have several ring-shaped beads around the tip.

At the in Figure 5d Emission electrode 57 shown, a drip element 81 is formed by a plate element 81 of emission electrode 57. The plate element 81 is designed in the form of a screen element.

However, the design of a drip element is not limited to the shape of the emission electrode. How Figure 6a As can be seen, it is also proposed according to the invention that a flow element 85 be formed in the region of an emission electrode 83. The inflow element 85 has the effect that liquid droplets that collect on the surface of the carrier element 87 do not reach the emission electrode 83, but are guided along the inflow element 85 to a drip element 89.

The result of the drip element is that contamination of the electrode end 90 is avoided, which could lead to the contamination being burned in and This leads to corking of the electrode tip, which could lead to a collapse of the plasma.

In Figure 7 A cross-sectional view of another embodiment of an emission electrode 91 is shown. The emission electrode 91 has a taper 95 at the electrode end 93. This taper 95 is formed in that the emission electrode 91 in the area of the electrode end 93 is hollow in areas, in particular in the shape of a hollow cylinder. In other words, the emission electrode 91 has an annular tip at the electrode end 93.

As a result, an annular taper 95 is formed at the electrode end 93. This also effectively prevents contamination of the electrode end 93. If, for example, an impurity, for example a drop, runs down along the emission electrode 91, it reaches this area of the taper 95 and the plasma detaches in this area of the emission electrode 91. However, the plasma cone then moves along the taper 95 to another point in the circle until the drop of liquid is detached and is discharged in an accelerated manner via the plasma of the counter electrode. Depending on the migration of the contamination at the electrode end, the plasma cone thus migrates along the taper, which means that the contamination does not overheat and burn-in at the electrode end or detachment of the plasma from the electrode 91.

In Figure 8 a further embodiment according to the invention of a separation device 101 is shown. The elements of the separation devices 101 which correspond to those of the separation device 1 have the same reference numerals, but increased by 100. In contrast to the deposition device 1, the deposition device 101 uses the counter electrode 109 in the Figures 3a to 4b used counter electrode elements shown.

In addition, the gas flow 107 is separated from the area in which the counter emission electrodes 111 are located by means of a separating element in the form of a separating film 123 which is permeable to the plasma or electrons. The separating film 123 is in particular a Teflon film. This has the property that it is gas-impermeable to the gas stream 107, but is permeable to the electrons supplied by means of the emission electrodes 111. In other words, the separating film 123 has the effect that the gas flow 107 cannot enter the region of the emission electrodes 111 and can lead to undesired contamination there. At the same time, it is ensured that an efficient separation of impurities from the gas flow in the direction of the counter electrodes 109 by means of the low-energy plasma that is arranged by the plasma cone 125 can be achieved.

Tests on separation devices known from the prior art have shown that the accumulation of impurities in the area of the emission electrodes is promoted by the fact that an electrostatic charge occurs in the area of a carrier element from which the emission electrodes emerge. The carrier element is usually made of a ceramic material. According to the invention it is now proposed that an electrostatic charge on the surface of the carrier element is reduced by means of discharge elements.

In Figure 9 a first embodiment of such a diverting element is shown. The carrier element 131 consists of a ceramic material in which, however, a discharge element 133 in the form of a conductive grid is embedded. The grid 133 has the effect that charge carriers that collect on the surface of the carrier element 131 are discharged, that is to say that electrostatic charging of the surface of the carrier element 131 is prevented in such a way that impurities cannot collect in the area of the emission electrodes 135. Furthermore, a discharge element is formed in that a recess 137 is formed between each of the electrodes 135. This shape supports the dissipation of the power carriers due to the electrical conductivity of the material and increases the resistance for contaminants to reach the carrier element.

In Figure 10 a further embodiment of a discharge element is shown. The carrier element 131 'has a discharge element 133' in the form of a coating applied to the carrier element 131 '. The coating 133 'is placed at the same electrical potential as the emission electrodes 135' and thus an electrostatic charge is avoided.

A corresponding diverting element 133 ″ can, as in FIG Figure 11 shown, can also be implemented in the form of a grid spaced apart from the carrier element 131 ″ through which the emission electrodes 135 ″ pass. In order to avoid electrostatic charging of the surface of the carrier element 131 ", the same electrical potential is also applied to the grid 133" as to the emission electrodes 135 ". Furthermore, the distance between the emission electrodes 135" and the grid or the protrusion of the emission electrode is set 135 "is selected by the grid in such a way that the plasma is ignited not between the grid and emission electrode 135" but between emission electrode 135 "and the counter electrode.

As in Figure 8 The inner area of a separating device 101 is represented by a carrier element 119, a wall 139 in which an inlet opening 141 connected to the inlet line 103 is formed, a second wall 143 in which an outlet opening 145 which is connected to the outlet line 105 , and a third wall 147, which is formed below the counter electrodes 109, surround.

In further embodiments, it can be provided that the diverting elements 133, 133 ', 133 "extend not only in the area of the carrier element 131, 131', 131" but also in the area of the first wall 139, the second wall 143 and / or the third Wall 147 are arranged. In this way, a "Faraday cage" is formed which has the effect that additional electrical fields within the separation device, which could influence the ion wind and "attract" impurities to the walls, are avoided. So all walls are at the same potential, in particular mass potential, so that an attractive force between the walls and the corresponding impurities is avoided. In particular, when the discharge elements are connected to ground, surface charges can be discharged immediately. To achieve these discharge elements, for example, the inlet and outlet sections of the separation device can have a conductive material or at least a conductive coating. The housing as a whole can also have a conductive material or a conductive coating. However, a conductive coating is preferred here. For example, a material with poor thermal conductivity can be provided with a correspondingly electrically conductive coating. This prevents, or at least reduces, the possibility that condensate can form on the inner walls of the separation device when the separation device cools down.

Further tests on separation devices known from the prior art have shown that disadvantageous turbulence of the blow-by flow occurs in the interior of a separation device 101, the turbulence in particular causing the blow-by to reach the area of the emission electrodes. Because the blow-by flow swirls the area of the emission electrodes, the particles carried along with the blow-by can reach the emission electrode along the upper wall of the separation device, and thereby collect at the tips of the emission electrodes in the upper area of the separation device . The functionality of the separation device can be impaired by the contamination of the emission electrodes.

According to the invention it is now proposed that influencing devices introduced between groups of emission electrodes in the upper region of the separation device influence the electric field formed by the emission or second electrodes and first electrodes or counter-electrodes in such a way that the clay winch is guided through the modified electric field that they no longer have an adverse effect. The disadvantageous turbulence of the blow-by should no longer occur, at least it should be reduced. As a result, no blow-by flows along the ceiling to the emission electrodes, as a result of which the tips of the emission electrodes in the upper area of the separation device remain clean for longer.

In Figure 13 a first embodiment of such an influencing device 160 is shown in a separating device in the form of a solid metal body with a substantially C-shaped profile. In this case, the influencing devices 160 are each integrated in alternation with a group 165 of emission electrodes 162 arranged in two rows in the separating device 101, with the region 168 of the influencing device 160 running along the upper wall of the separating device 101 integrally via an, in particular concave, connecting region 161 with the The area 169 of the influencing device 160 that extends along the side walls of the separating device is connected. In the lower region, the influencing device 160 is conductively connected to the counter-electrodes 163 ′ lying opposite the region 168 of the influencing device 160.

In Figure 14 A schematic plan view of the upper region of the deposition device 101, which groups 165 comprising two rows of two emission electrodes 162 and influencing devices 160, is shown. It can be seen here again how the emission electrodes 162, which in the embodiment shown of the separation device 101 in _ Figure 14 grouped into two rows each, alternating with an influencing device 160 according to the invention, extending transversely in the upper region of the separating device 101. In this case, an influencing device 160 in the form of an essentially C-shaped insert is continuously and repeatedly placed between two rows of electrodes 162 each, in order to be able to protect all electrode tips as far as possible through the positive effect of this solution. A distance d between a group 165 of emission electrodes 162 and the influencing device 160 is selected to be so large that no sparking can occur from the emission electrodes 162 to the influencing device 160.

In Figure 15a the field lines of the electric field 164 'are shown schematically, which are formed by the emission electrode 162 and the counter-electrode (not shown) located in the lower area of the picture if no influencing device according to the invention with earthed end faces is provided inside the separating device 101. In Figure 15b the field lines of the electric field 164 ″ for the same emission electrode 162 are shown schematically. The electric field 164 ″ is formed between the emission electrode 162 and the counter electrode (not shown) in the lower area. However, an influencing device with grounded end faces is now shown. In the course of various experiments it has been empirically shown that the field distribution of the electric field 164 ″ from Figure 15b the turbulence that occurs in the blow-by is eliminated or at least reduced, since the ion winds are guided by the modified field shape of the electric field 164 ″ in such a way that they no longer have a detrimental effect on the blow-by. In particular, the end faces of the influencing devices 160 cause a field shift. The particles are charged and separated earlier, so that the overall degree of separation increases. This advantageously means that blow-by no longer flows along the ceiling to the emission electrodes 162 and thus the tips of the emission electrodes 162 in the upper region of the separation device 101 are longer stay clean, since fewer particles are deposited on the emission electrodes 162 than is the case, for example, with the field lines of the field 164 'without influencing devices.

As described above, an influencing device 160 is provided in the separating device 101, alternating with a group comprising two rows of emission electrodes 162, whereby as much as possible all emission electrode tips are protected by the influencing device from deposits of blow-by particles. Because by repeating the influencing device, the positive effect is transferred to all emission electrodes or groups of emission electrodes. Of course, instead of the two rows of emission electrodes listed here as an example, it is also possible to attach only a single row of emission electrodes, alternating with an influencing device, or alternating three rows of emission electrodes with one influencing device, or a large number of rows of emission electrodes, each alternating with one To attach influencing device. Of course, the person skilled in the art can also provide other arrangements of the emission electrodes 162 within a group of emission electrodes 165 instead of rows of electrodes.

In the device according to the invention, the influencing devices 160 only depend on the end flanks, so that a solid body like that in the Figures 13 and 14th is used for the influencing devices, represents an implementation form of the influencing devices 160 that is not absolutely necessary. These devices 160 according to the invention can also be implemented, for example, by grounded sheet metal strips or the like. In order to bring about the positive effect of the modified field distribution, the formation of round connection areas 161, as shown in FIG Figures 13 and 14th are formed in the influencing devices 160, not necessary. The ones in the Figures 13 and 14th Rather, existing rounded connection areas 161 serve for easier installation and easier production. In addition, other cross-sectional profiles of the influencing device according to the invention, in particular cross-sectional profiles in a plane perpendicular to the flow direction of the blow-by, can also be implemented without this opposing the positive effect.

This shows Figure 16a Another possible cross-sectional shape of the influencing device 160 according to the invention, which has an arcuate shape. In Figure 16b is that out Figure 13 and Figure 14 known, essentially C-shaped design with connecting areas 161 connecting the individual segments. In Figure 16c in a third possible cross-sectional shape of the influencing device according to the invention, the lateral extensions of which extend perpendicularly from the part running transversely in the upper area of the separating device 101 and thus have right-angled connecting areas 167 instead of roundings.

In Figure 12 Finally, a modification of a device according to the invention is shown, which enables a method according to the invention to be carried out. The separating device 151 has a carrier element 153, the emission electrodes 155 being attached to the carrier element 153 by means of actuators 157. The acuators 157 have piezoelectric elements, which enable the emission electrodes 155 to be set in (ultrasonic) oscillations. This has the effect that the emission electrodes can be cleaned in that contaminants adhering to the emission electrodes 155 are removed by means of ultrasound.

In an embodiment not shown, it can be provided that the emission electrodes 155 can be formed from an SMA material, that is to say a shape memory material, or at least comprise this. The shape memory material has the effect that the emission electrode is deformed when the temperature rises. As a result of this deformation, any impurities or adhesions located on the emission electrode are deformed in such a way that they "flake off" from the surface.

The features shown in the above description, in the claims and in the figures can be essential for the invention in its various embodiments both individually and in any combination, the invention being defined by the following claims.

List of reference symbols

A1

Cutout

N

Normal direction

B, C

direction

X, Y

axis

d

distance

1

Separation device

3

Entry line

5

Outlet line

7th

Gas flow

9

Counter electrode

11

Emission electrode

13

connection

15th

Collection room

17th

Bulkhead elements

19th

Support element

21st

Thermoset body

31, 31 ', 31 "

Counter electrode element

33, 33 ', 33 "

Plateau area

35

Spacer

37

Basic level

39

Connecting element

41

Plasma cone

43 ', 43 "

Connecting device

51

Emission electrode

53

Emission electrode

55

Emission electrode

57

Emission electrode

59

Kink

61

Electrode area

63

End of feed

65

Electrode area

67

Bend

69

Electrode area

71

Electrode end

73

Draining element

75

Twist

77

Electrode end

79

Draining element

80

Draining element

81

Plate element

83

Emission electrode

85

Inflow element

87

Support element

89

Draining element

90

Electrode end

91

Emission electrode

93

Electrode end

95

rejuvenation

101

Separation device

103

Entry line

105

Outlet line

107

Gas flow

109

Counter electrode

111

Emission electrode

113

Connection

115

Collection room

119

Support element

121

Thermoset body

123

Release film

125

Plasma cone

131, 131 ', 131 "

Support element

133, 133 ', 133 "

Discharge element

135, 135 ', 135 "

Emission electrode

137

deepening

139

Wall

141

Inlet opening

143

Wall

145

Outlet opening

147

Wall

151

Separation device

153

Support element

155

Emission electrode

157

Actuator

160

Influencing device

161

Connection area

162

Emission electrode

163, 163 '

Counter electrode

164 ', 164 "

electric field

165

group

167

Connection area

168

Area

169

Area

Claims (14)

1. A device (1, 101, 151) for separating off liquid and/or particulate contaminants from a gas flow (7, 107), in which a flow path of the gas flow (7, 107) runs between at least one first electrode (9, 31, 109) acting as a counter electrode and at least one second electrode (11, 111, 51, 53, 57, 135, 135', 135", 155) acting as an emitter electrode and having an electrode end (71, 77, 90) oriented in the direction of the first electrode, and a direct-current voltage exceeding the breakdown voltage can be applied between the first electrode (9, 31, 109) and the second electrode (11, 111, 51, 53, 57, 135, 135', 135", 155) in order to form a stable low-energy plasma (41, 125), wherein
   the second electrode (11) extends substantially along a first axis (X) in a first direction and the first electrode (31) has at least one plateau region (33) which is arranged opposite the second electrode (11) and which extends at least regionally in a first plane running substantially perpendicular to the first direction (X), wherein
   the plateau region (33) is connected to a base level (37) by means of a spacer element (35) extending against the first direction (X),
   characterized in that
   the plateau region (33) is connected to the spacer element (35) by means of at least one connecting element (39).
2. The device according to claim 1, characterized in that

   (i) the spacer element (35) is electrically conductive and/or the connecting element (39) runs substantially perpendicular to the first direction and along the first plane
3. The device according to claim 1 or 2, characterized in that
   the plateau region (33) is arranged coaxially to the second electrode (11), and/or the flow path runs substantially between the second electrode (11) and the plateau region (33), the plateau region (33) has, at least regionally, in particular, in the edge region, a surface that is curved in the direction of the second electrode (11) and/or against the first direction (X),
   the plateau region (33) is arranged a distance from the base level (37) of the first electrode (31) in the direction of the second electrode (11), and/or a plurality of second electrodes (11) are present, and the first electrode has a plurality of plateau regions (33), wherein each of the second electrodes (11) is associated with a respective plateau region (33).
4. The device according to one of the preceding claims, characterized in that
   the spacer element (35) runs coaxially to the first axis (X), or the spacer element (35) runs at a distance from the first axis (X), preferably at least regionally parallel to the first axis (X), and/or the first electrode (31) has, at least regionally, a substantially C-shaped cross-section, in particular, the C-shape being formed of the base level (37), the spacer element (35), the connecting element (39), and the plateau region (33).
5. The device according to one of the claims 2 to 4, characterized in that

   (a) the plateau region (33), the spacer element (35), the base level (37), and/or the connecting element (39) are configured at least regionally as a single piece; the plateau regions (33', 33") are connected by means of at least one connecting device (43, 43") that extends substantially parallel to the base level and/or has a lesser extension in at least one direction of the first plane than the plateau regions (33', 33"), wherein the plateau regions (33') are arranged along a straight line in a direction perpendicular to the first axis, in particular, the connecting devices (43') extend substantially along the straight line and/or a network and/or matrix is configured by means of the connecting devices (43"), wherein at least one plateau region (33") is arranged on at least one of the points of intersection of the connecting devices (43"), wherein the network and/or matrix extends along the first plane, and/or

   (b) the plurality of plateau regions (33) are provided by at least one counter electrode element (31) that is preferably configured at least regionally as a punched sheet metal part, in particular, the plateau regions (33) are arranged in the counter electrode element (31) along a second direction and/or at least two counter electrode elements (31) can be arranged with mirror symmetry relative to one another, preferably at least regionally interlocking with one another, preferably offset from one another in such a manner that the plateau regions (33) of the respective counter electrode elements (31) are arranged offset relative to one another along the respective second direction, or the punched sheet metal part forms the plateau regions (33', 33") and connecting elements (43', 43").
6. The device according to one of the preceding claims, characterized by
   at least one drip element (59, 73, 79, 80, 89) which is operatively connected to the second electrode (51, 53, 55, 57, 83) and by means of which fluid particles of the gas flow that are moving in the direction of and/or along the second electrode (51, 53, 55, 57, 83) can be collected in such a manner that the fluid particles come loose from the drip element (59, 73, 79, 80, 89) at a distance from the electrode end (71, 77, 91), wherein particularly

   (i) the drip element (89) is at least regionally encompassed by at least one approach flow element (85) arranged in the region of the second electrode (83), and/or

   (ii) the second electrode (51, 53, 55, 57) encompasses the drip element (59, 73, 79, 80) at least regionally, wherein fluid particles flowing along the second electrode (51, 53, 55, 57) in the direction of the electrode end (71, 77) can be collected at a distance from the electrode end (71, 77) by means of the drip element (59, 73, 79, 80) in such a manner that the fluid particles come loose from the second electrode (51, 53, 55, 57) at a distance from the electrode end 71, 77), wherein, in particular, the electrode end (71) and an infeed end (63) of the second electrode (51) that is opposite the electrode end (71) are arranged offset from one another along a first axis (Y) extending in a first direction in such a manner that the electrode end (71) is arranged close to the first electrode, and the drip element (59) is formed at least regionally by a transition region of the second electrode that is arranged between a first electrode region (61) in which at least one surface region of the second electrode (51) and/or the electrode (51) extends from the infeed end (63) in the direction of the electrode end (71) in a direction with a direction component along the first axis (Y)-and a second electrode region (65) in which at least one surface region of the second electrode (51) and/or the second electrode (51) extends at least regionally in a direction with a direction component against the first direction, wherein, preferably, at least one surface region of the second electrode (51) and/or the second electrode (51) extend from the infeed end (63) in the direction of the electrode end (71), in particular, subsequently to the second electrode region (65), in a third electrode region (69) in a direction with a direction component along the first axis (Y), preferably in such a manner that the drip element (59) is arranged along the first axis above the electrode end (71).
7. The device according to claim 6, characterized in that
   the drip element is encompassed by and/or constituted of at least one winding (75) of the second electrode (53), at least one kink (59, 89) of the second electrode (51) and/or the approach flow element (85), at least one helical region of the second electrode, at least one protuberance (79) of the surface of the second electrode (55) and/or the approach flow element, at least one skirt, and/or at least one disc element (81); the drip element (79, 80) circumferentially surrounds the second electrode; preferably with radial symmetry, the drip element (73) is arranged downstream of the gas flow; and/or the approach flow element (85) is arranged upstream of the gas flow; and/or the drip element (59, 73, 79, 80, 89) is configured at least regionally integrally with the second electrode (51, 53, 55, 57) and/or the approach flow element (85).
8. The device according to one of the preceding claims, characterized in that
   the second electrode (91) has at least one taper (95), in particular, in the region of the electrode end (93), wherein particularly

   (i) the taper is configured in the form of at least one tip, at least one ridge, and/or at least one edge (95), and/or

   (ii) the second electrode has a substantially cylindrical, triangular, quadratic, rectangular, and/or polygonal cross-sectional shape in a plane perpendicular to a main extension direction, in particular, the first direction; the second electrode has an end surface inclined with respect to the main extension direction, in particular, in the region of the electrode end; in particular, the taper is encompassed by an edge of the end surface; the second electrode has-in particular, in the region of the electrode end (93)-at least regionally a hollow region in which the second electrode is configured so as to be hollow, preferably in the shape of a hollow cylinder, tube, and/or a cone shell; wherein preferably the taper (95) is encompassed by at least one end edge of the wall of the hollow region; in particular, the taper is circumferential on the electrode end (93); and/or the second electrode comprises a carbon material, at least regionally, in particular, in the region of the electrode end; and/or the second electrode comprises at least one coating-preferably one that reduces the attachment of particles and/or fluid, in particular, a coating comprising titanium nitride, nanosol, at least one nanoparticle-containing material, at least one material constituting a surface having a nanostructure, and/or chromium nitride-at least regionally, in particular, in the region of the electrode end.
9. The device according to one of the preceding claims, characterized in that
   the device comprises at least two second electrodes (135, 135', 135"), preferably a multitude of second electrodes (135, 135', 135"), wherein the second electrodes (135, 135', 135") extend out from at least one first support element (131, 131', 131"), and
   at least one drain device (133, 133', 133") is provided in order to reduce an electrostatic charge of the support element (131, 131', 131") and/or to discharge charge carriers collecting on a surface of the support element (131, 131', 131"), at least in the region between the second electrodes (135, 135, 135").
10. The device according to claim 9, characterized in that

    (i) the second electrodes (135, 135', 135") pass at least regionally through the support element (131', 131, 131") and/or that the support element (131, 131', 131") comprise at least one ceramic element;
    the drain device comprises at least one drainage element (131, 131") that is at least regionally installed on the support element and/or at least regionally embedded in the support element, wherein the drainage element preferably comprises at least one drain coating (131') (in particular, an electrically conductive one), at least one drain fabric (in particular, a polyamide-containing and/or grounded one), and/or at least one metal band such as a copper band, and/or the drain device is configured as a conductive tunnel element, and/or
    the drain device comprises at least one depression (137) at least regionally configured in the support element, and/or

    (ii) the drain device comprises at least one drainage device (133") arranged in the region between the electrode ends of the second electrodes and the support element, wherein, in particular, the drainage device comprises at least one conductive mesh (133"), at least one conductive foam, at least one shield element that surrounds the respective second electrode at least regionally and preferably is curved radially outward in the direction of the electrode end, wherein, in particular, the drainage device (133") is at the same electrostatic potential as the second electrodes, and/or characterized in that
    the drain device (133, 133', 133"), the drainage element (133, 133"), the drain coating, and/or the drainage device stretch at least regionally along and/or in a first wall (139) and/or second wall (143) that extend(s) at least regionally in a direction between the second electrode (135, 135', 135") and the first electrode (109) in a direction along the first axis (X) and/or in the first direction and/or opens into the at least one inlet opening (141) or an outlet opening (145), and/or along and/or in a third wall (147) that extends at least regionally in parallel to the first support element (131, 109', 131"), at least regionally below the first electrode (131), and/or at least regionally on the side of the first electrode (109) that faces away from the second electrode (135', 135, 135").
11. The device according to one of the preceding claims, characterized in that the device comprises at least two second electrodes (162), preferably a multitude of second electrodes (162), and at least one influencing device (160) for influencing the electrical field formed by the at least two second electrodes (162) can be and/or is arranged at least regionally between the at least two second electrodes (162).
12. The device according to claim 11, characterized in that

    (i) the influencing device (160) can be and/or is arranged substantially at least regionally opposite at least one first electrode (163, 163'), preferably a plurality of first electrodes (163, 163'), and/or a (preferably predetermined) electric potential can be or is applied, and/or

    (ii) the influencing device (160) can be and/or is conductively connected to the at least one first electrode (163'), the potential of the first electrode (163) can be and/or is applied to the influencing device (160), and/or the influencing device and the drain device, the drainage device, and/or the drainage element are at least regionally configured together.
13. A method for operating a device according to one of the preceding claims, wherein
    a liquid and/or particulate contaminant-containing gas flow is supplied to the device (151), the gas flow is guided at least partially along a flow path configured between at least one first electrode and at least one second electrode (155) in order to separate the contaminants off from the gas flow, and a direct-current voltage exceeding the breakdown voltage is configured between the first electrode and the second electrode (155) in order to form a stable low-energy plasma, characterized in that
    the method furthermore comprises a cleaning step for cleaning the first electrode and/or the second electrode (155).
14. The method according to claim 13, characterized in that
    during the cleaning step, a ground potential is applied to at least a first group of a plurality of second electrodes (155), or a voltage that exceeds the direct-current voltage and produces a breakdown between the first electrode and the second electrodes (155) of the first group is applied, in particular, while the direct-voltage for forming the low-energy plasma is applied to at least one second group of the second electrodes, wherein preferably the second electrodes (155) are alternately associated with the first group and the second group.

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