NL2007548C2

NL2007548C2 - Particle catch arrangement for catching particles from a polluted particle flow.

Info

Publication number: NL2007548C2
Application number: NL2007548A
Authority: NL
Inventors: Roland Willibrordus Niekerk; Jacobus Johannes Cornelis Vermeulen; Willibrordus Nicolaas Johannes Ursem; Johannes Cornelis Maria Marijnissen; Rein Andre Roos
Original assignee: Konink Bam Groep Nv
Priority date: 2011-10-06
Filing date: 2011-10-06
Publication date: 2013-04-09

Description

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P30924NL00/RAL/RWY

Title: Particle catch arrangement for catching particles from a polluted particle flow

The invention relates to the field of catching particles from an particle flow by means of electrostatic fields and ionic winds and/or Corona winds. More in particular, the field relates to removing smut, fine dust and exhaust gas particles from polluted air in tunnels, factory buildings, stables and polluted areas in buildings in general.

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Particle catch arrangement are used to remove particles from polluted air. Particles, such as smut, fine dust and exhaust gas particles pollute the air and are extremely unhealthy for human beings. Particle catch arrangements using electrostatic fields combined with corona chargers are used to catch particles and remove them from polluted air. The 15 corona charger locally ionizes the air resulting in ionized particles. Often these corona chargers have a sharp electrode. The ionized particles are attracted by a differently charged more distant lying surface or electrode. The attraction results from an exertion of an electrostatic force resulting from an electrostatic field between the corona charger and the more distant lying surface or electrode. The moving ionized particles collide with neutral 20 (uncharged) molecules en route to the surface or electrode and create a pumping action resulting in air movement. The resulting air movement is generally known as ion wind, also sometimes referred to as ionic wind and corona wind even though these concepts are not entirely synonymous.

For example, W02007/100254 shows a particle catch arrangement comprising 25 positively charged antenna like objects that locally ionize air and negatively charged collector plates that attract ionized particles and collects them. The positively charged antenna and the negatively charged plates generate an electrostatic field above a road, such that smut, fine dust and exhaust gas particles are removed from an area above the road where the electrostatic field is generated.

30 Drawback of this particle catch arrangement is that only relatively large polluted particles are removed. The ionized particles only collide with particles that are sufficiently large. The larger the polluted particle the larger the chance that a moving ionized particle collides with polluted particle.

Moreover, a relative large electrostatic field must be generated to filter the polluted 35 air. The required relative large electrostatic field results in relative large energy required and/or relative large collector plates. This results in a negative impact on environmental issues such as visual pollution and/or energy usage.

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It is an object of the present invention to eliminate the abovementioned problems or at least provide an alternative.

In particular it is an object of the present invention to provide a particle catch arrangement that is able to remove relatively small polluted particles from polluted air.

5 This object is received by a particle catch arrangement for catching particles from an particle flow according to claim 1. This particle catch arrangement comprises a first end and a second end. Preferably, the support structure is made from metal. The particle catch arrangement comprises a charged fist wire emitter electrode having a first wire longitudinal axis for locally ionizing particles. The first wire emitter electrode is a relatively sharp object 10 resulting in a corona charge of polluted air, such that ionized particles are generated. The first wire emitter electrode is held in tension by the support structure between the first end and the second end via isolators electrically isolating the first wire emitter electrode from the support structure. The first wire emitter electrode is elongated. The isolators isolate the first wire emitter electrode from the support structure such that the first wire emitter electrode 15 may have a different electrostatic charge with respect to the support structure. Furthermore, the particle catch arrangement comprises a guide surface for guiding at least a part of the particle flow substantially in a plane perpendicular to the first wire longitudinal axis. The guide surface is spaced away parallel from the first wire emitter electrode in a first direction perpendicular with respect to the first wire longitudinal axis. The first direction is defined 20 along a smallest distance between the first wire emitter electrode and the guide surface. The guide surface has a different electrostatic charge with respect to the first wire emitter electrode for providing a first electrostatic force on the ionized particles from the first wire emitter electrode towards the guide surface. The first electrostatic force results from a first electrostatic field provided from the first wire emitter electrode towards the guide surface in a 25 direction substantially equal to the first direction. Therefore, the first electrostatic force is substantially in a direction equal to the first direction. In particular, this results in the particle flow following a trajectory towards the guide surface. In particular, the first wire emitter electrode is charged with a positive electrostatic charge and the guide surface is charged with a negative electrostatic charge or neutral electrostatic charge, for example when the 30 guide surface is earthed. A positive electrostatic charge results in positive ionized particles.

The support structure furthermore comprises a first longitudinal bar spaced away parallel from the first wire emitter electrode in a second direction perpendicular with respect to the first wire longitudinal axis. In particular, the longitudinal bar is elongated over a length at least equal to the first wire emitter electrode. The second direction has a component that 35 is opposite to the first direction, meaning aligned with the first direction but in opposite direction. The second direction also has a component that is perpendicular with respect to the first direction. This implies that the first wire emitter electrode is provided substantially -3- between the guide surface and the first longitudinal bar. In other words, the first longitudinal bar is spaced away from the first wire emitter electrode as well as from the guide surface.

The first longitudinal bar has a different electrostatic charge with respect to the first wire emitter electrode for providing a second electrostatic force on the ionized particles. The 5 second electrostatic force is exerted from the first wire emitter electrode towards the first longitudinal bar. The electrostatic force results from a second electrostatic field from the first wire emitter electrode towards the longitudinal bar in a direction substantially equal to the second direction. Therefore, the second electrostatic force is substantially in a direction equal to the second direction.

10 The first longitudinal bar defines the second electrostatic field, and thus the second electrostatic force such that the first longitudinal bar is suitable for boosting the particle flow such that the particle flow at least partly follows a looped trajectory around the first wire emitter electrode and the first longitudinal bar seen in the plane perpendicular to the first wire longitudinal axis. Without the first longitudinal bar the particle flow only comprises a 15 trajectory towards the guide surface. Having the second direction opposite to the first direction and comprised of a component perpendicular to the first direction allows a particle to be deflected by the guide surface and boosted by the second electrostatic force and/or field. In particular, the boosting of the particle flow is directly when the ionized particles flow in the second electrostatic field and/or is indirect when ionized particles are captured as a 20 result of scavenging by a particle flow from the first wire emitter electrode towards the first longitudinal bar. This means that ionized particles, but also small other polluted particles are draught towards the first longitudinal bar. The first- and second electrostatic forces, together with a scavenging effect results in the particle flow following the looped trajectory.

The second electrostatic force results in an boosting by scavenging of an ionized 25 particle. The ionized particle does not follow a linear trajectory hitting the guide surface, but is boosted both by the guiding surface and directly and/or indirectly by the second electrostatic force. The second electrostatic force is in the second direction towards the first longitudinal bar and away from the first wire emitter electrode as well as away from the guide surface. An ionized particle shall therefore be boosted from the guiding surface towards the 30 first longitudinal bar and shall follow a looped trajectory around the first wire emitter electrode as well as well as the first longitudinal bar.

Because of the ionized particles following a looped trajectory the chance of the ionized particle to collide with an air molecule is increased. Moreover, every time the ionized particle collides with an air molecule a pumping air action is resulting in an air movement 35 leading to a strong looped particle flow. Each time an ionized particle makes a loop around the first wire emitter electrode and the first longitudinal bar the particle flow is getting stronger. This increases the scavenging effect such that also small polluted air molecules -4- are captured. Therefore, not only the air molecules that collide with ionized particles are moved by the particle flow, but also substantially smaller air molecules which do not contact the ionized particles are moved by the particle flow by scavenging. The ionized particles are colliding with air molecules forming heavier charged particles. When the charged particles 5 are to heavy, boosting is not sufficiently present to boost the charged particle. This charge particle shall follow the guide surface and in the end shall be collected by the guide surface or by a dedicated collector provided along the guide surface. The particle flow that follows a looped trajectory is also named a cyclone and/or circular particle flow.

Preferably, the particle catch arrangement according to the invention provides a first 10 gap between the first wire emitter electrode and the guide surface. Moreover, a second gap is provided between the guide surface and the first longitudinal bar. The gaps are suitable for allowing a particle flow to follow a looped trajectory around the first wire emitter electrode and the first longitudinal bar in the plane perpendicular to the first wire longitudinal axis.

In an embodiment of the particle catch arrangement according to the invention, the 15 particle catch arrangement further comprises a second wire emitter electrode having a second wire longitudinal axis for locally ionizing particles. The second wire emitter electrode is also held in tension by the support structure between the first end and the second end via isolators electrically isolating the second wire emitter electrode from the support structure. The isolators allows that the electrostatic charge of the second wire emitter electrode is 20 differently chargeable compared to the support structure, but also compared to the first wire emitter electrode. The second wire emitter electrode is being spaced apart parallel from the first wire emitter electrode. Thereby, they define a wire gap between the first- and second wire electrode emitter which results in the particle flow following a trajectory through the wire gap towards the guide surface. This is particularly advantageous as this arrangement of wire 25 emitter electrodes reinforce boosting of the particle flow. The guide surface is spaced away parallel from the second wire emitter electrode in a third direction perpendicular with respect to the second wire longitudinal axis. The third direction is defined along a smallest distance between the second wire emitter electrode and the guide surface. The second wire longitudinal axis is parallel to the first wire longitudinal axis and parallel to the guide surface. 30 The guide surface has a different electrostatic charge compared to the second wire emitter electrode for providing a third electrostatic force on the ionized particles from the second wire emitter electrode towards the guide surface. The third electrostatic force results from a third electrostatic field provided from the second wire emitter electrode towards the guide surface in a direction substantially equal to the third direction. Therefore, the third 35 electrostatic force is substantially in a direction equal to the third direction. In particular, this results in the particle flow at least partly following a trajectory from between the second wire emitter electrode and the first wire emitter electrode towards the guide surface.

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The support structure comprises a second longitudinal bar spaced away parallel from the second wire emitter electrode in a fourth direction perpendicular with respect to the longitudinal axis. The fourth direction is along a smallest distance between the second longitudinal bar and the second wire emitter electrode.

5 The fourth direction has a component that is opposite to the third direction, meaning aligned with the third direction but in opposite direction. The fourth direction also has a component that is perpendicular with respect to the third direction. This implies that the second wire emitter electrode is provided substantially between the guide surface and the second longitudinal bar. In other words, the second longitudinal bar is spaced away from the 10 second wire emitter electrode as well as away from the guide surface.

The second longitudinal bar has a different electrostatic charge with respect to the second wire emitter electrode for providing a fourth electrostatic force on the ionized particles from the second wire emitter electrode towards the second longitudinal bar.

The fourth electrostatic force results from a fourth electrostatic field from the second 15 wire emitter electrode towards the second longitudinal bar in a direction substantially equal to the fourth direction. Therefore, the fourth electrostatic force is substantially in a direction equal to the fourth direction.

The second longitudinal bar defines the fourth electrostatic field, and thus the fourth electrostatic force is such that the second longitudinal bar is suitable for boosting the particle 20 flow such that the particle flow at least partly follows a looped trajectory around the second wire emitter electrode and the second longitudinal bar substantially seen in the plane perpendicular to the second wire longitudinal axis.

Seen in the plane perpendicular to the wire longitudinal axes, two looped trajectories, being a first- and second looped trajectory, additionally boost each other. The first looped 25 trajectory has a loop direction that is in an opposite loop direction compared to the second looped trajectory. Having two parallel spaced wire emitter electrodes results in the two looped trajectories of a particle flow. The particle flow of each looped trajectory is stronger than a separate looped trajectory generated by an individual wire emitter electrode. It is therefore particularly advantageous to have the second wire emitter electrode and the 30 second longitudinal bar spaced away parallel from the guiding surface, the first wire emitter electrode and the first longitudinal bar.

Preferably, the particle catch arrangement according to the invention provides a third gap between the second wire emitter electrode and the guide surface and a fourth gap between the guide surface and the second longitudinal bar. The third and the fourth gap are 35 suitable for allowing a particle flow to follow a (second) looped trajectory around the second wire emitter electrode and the second longitudinal bar in a plane perpendicular to the second wire longitudinal axis.

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In a further embodiment, the component of second direction perpendicular to the first direction is opposite to the component of the fourth direction perpendicular to the third direction.

5 This is advantageous as the second electrostatic force and the fourth electrostatic force comprise opposing components, resulting in a further boosting to form the two separate looped trajectories of the particle flow.

In a further embodiment, a smallest distance between the first wire emitter electrode and the guide surface and a smallest distance between the second wire emitter electrode 10 and the guide surface is substantially equal.

This is advantageous as this results in the first looped trajectory and the second looped trajectory being equally strong, such that the first looped trajectory boosts the second looped trajectory in an equal amount as vice versa.

In an embodiment of the particle catch arrangement according to the invention, the 15 particle catch arrangement comprises a first collector provided to the support structure. The first collector is arranged near the guide surface for receiving particles from the particle flow.

This is advantageous, as the polluted particles, being the ionized particles collided with dust, smut and/or exhaust gas particles, are collected centrally.

In particular, the fist collector is arranged in a trajectory of the particle flow, preferably 20 at an end thereof.

Preferably, the first collector is provided to the guide surface.

Preferably, the first collector is charged with a charge that is different compared to the first wire emitter electrode and has a voltage larger than the guide surface.

This is advantageous, as the polluted particles do not end up scattered on the guide 25 surface, but more centrally in het first collector.

In further embodiment, the first collector comprises a charged substrate for capturing particles from the particle flow by means of electrostatic forces.

This is advantageous as it allows for capturing suspended particles such as oil mist, haze and fog.

30 In an even further alternative embodiment, the first collector comprises protruding fibres for capturing particles from the particle flow by means of molecular forces.

This is advantageous as it allows for additional capturing of particles from the particle flow by means of Coulomb forces. Another advantage is that a thickness of the fibres correspond with capturing of a certain size of a to be captured particle. The thickness of the 35 fibres are designed to capture a certain desired size of a to be captured particle.

In an particular advantageous embodiment, the substrate is provided between the guide surface and the protruding fibres.

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In an embodiment of the particle catch arrangement according to the invention, the first wire emitter electrode comprises longitudinally spaced sharp discharge means for locally ionizing particles, wherein at least one discharge means is provided in a plane perpendicular to the first wire longitudinal axis comprising the particle flow following the looped trajectory.

5 This is advantageous as the sharp discharge means allows for focussing an amount of generating ionizing particles at a desired location along the first wire longitudinal axis. When the sharp discharge means is arranged in a plane perpendicular to the first wire longitudinal axis, the number of ionized particles increases seen in the plane perpendicular to the first wire longitudinal axis. This results in a more efficient looped trajectory of the 10 particle flow.

In an embodiment of the particle catch arrangement according to the invention, the first wire emitter electrode is positively charged by applying a positive voltage. The first longitudinal bar is charged with a voltage lower than the voltage of the first wire emitter electrode. And the guide surface is charged with a voltage lower than the voltage of the first 15 longitudinal bar. Preferably, the first longitudinal bar is charged with a negative voltage and the guide surface is neutrally charged or earthed.

This is advantageous as a compact particle catch arrangement is acquired. By providing the voltages such, it allows the at least one longitudinal bar to be arranged more close to the first wire emitter electrode and thus closer to the guide surface while the second 20 electrostatic force is still strong enough to generate the looped trajectory.

In an embodiment of the particle catch arrangement according to the invention, a smallest distance between the guide surface and the first wire emitter electrode is larger or equal to a smallest distance between the first longitudinal bar and the first wire emitter electrode.

25 This is advantageous, as it provides for a compact particle catch arrangement in which the second electrostatic force is sufficient large to allow a charged particle to follow a looped trajectory around the first wire emitter electrode and the first longitudinal bar.

In a further embodiment, the smallest distance between the guide surface and the first wire emitter electrode is 30 cm, the smallest distance between the first longitudinal bar 30 and the first wire emitter electrode is 30 cm, and the length of the first wire emitter electrode is 6 m.

This is advantageous, as it allows for a compact particle catch arrangement, suitable for removing polluted particles from buildings and/or traffic roads, in which the second electrostatic force is sufficient large to allow a charged particle to follow a looped trajectory 35 around the first wire emitter electrode and the first longitudinal bar.

In an embodiment of the particle catch arrangement according to the invention, the particle catch arrangement further comprises at least one voltage generator being -8- configured to receive a voltage setting signal and configured to provide a voltage to the first wire emitter electrode and/or the first longitudinal bar representative for the voltage setting signal. The particle catch arrangement also comprises a control unit configured to provide the voltage setting signal depending on the electrostatic charge of the guide surface, the 5 electrostatic charge of the first wire emitter electrode, a smallest distance between the first wire emitter electrode and the guide surface, and a smallest distance between the first wire emitter electrode and the first longitudinal bar.

This is advantageous as it allows generating an optimal looped trajectory around the first wire emitter electrode and the first longitudinal bar based on the smallest distance 10 between the first wire emitter electrode and the guide surface and a smallest distance between the first wire emitter electrode and the longitudinal bar. Both these distances are fixed and/or can be easily determined by means of measuring. The distances must not be too large as the generated electrostatic fields are to weak to boost a charged particle in a trajectory around the first wire emitter electrode and the first longitudinal bar. To compensate 15 for such a weak electrostatic field the electrostatic charges of the first wire emitter electrode and/or the first longitudinal bar are increased. The control unit provides the voltage setting signal representative for a compensation. This also allows for a detailed tuning of the electrostatic fields such that an optimal, that is a relatively strong looped trajectory of the particle flow is generated.

20 In an embodiment of the particle catch arrangement according to the invention, the control unit is configured to provide a voltage setting signal that is representative to the second electrostatic force being larger than the first electrostatic force.

By controlling the electrostatic charge of the first wire emitter electrode and the first longitudinal bar the second electrostatic force is provided with a desired strength. The 25 second electrostatic force acts on ionized particles and results from the second electrostatic field generated from the first wire emitter electrode towards the first longitudinal bar. When the second electrostatic force is larger than the first electrostatic force, that is in the first direction from the first wire emitter electrode towards the guide surface, a charged particle can be boosted towards the first longitudinal bar and afterwards around the first wire emitter 30 electrode and the first longitudinal bar seen in a plane perpendicular to the first wire longitudinal axis. The boosting is directly provided by having the ionized particle in the second electrostatic field and/or indirectly as a result of scavenging.

In a further embodiment the particle catch arrangement further comprises at least one voltage sensor for providing a voltage measurement signal representative for a voltage 35 in the first longitudinal bar, and/or a voltage in the first wire emitter electrode, and/or a voltage in the guide surface, wherein the control unit is configured to receive the voltage measurement signal.

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This is advantageous, as the control unit is able to set the desired voltages to the first wire emitter electrode, and/or guide surface, and/or longitudinal bar based on an actual value of their respective voltages. This increases robustness and integrity of the particle catch arrangement.

5 In an alternative further embodiment the particle catch arrangement further comprises at least one current sensor for providing a current measurement signal representative for a current in the first longitudinal bar, and/or a current in the first wire emitter electrode, and/or a current in the guide surface, wherein the control unit is configured to receive current voltage measurement signal.

10 Currents occur due to ions that flow from the first wire emitter electrode to the guide surface and/or the first longitudinal bar. When the guide surface and/or the first longitudinal bar are provided with a conductive material, such as an electrode, a current shall occur in the respective guide surface and/or the first longitudinal bar. Measuring this current by the respective at least one current measurement signal is advantageous as it allow timely 15 maintenance and an indication of an amount of captured particles.

The first wire emitter electrode degraded with time and release and/or disperses small metal particles resulting in the first wire emitter electrode getting thinner. This is directly seen in an increase of the current in the receiving guide surface and/or first longitudinal bar.

When particles collide with ions, these ions are captured by the particle flow and for 20 example shall follow the first looped trajectory. This is directly seen in a decrease of the current in the receiving guide surface and/or first longitudinal bar.

In an embodiment of the particle catch arrangement according to the invention, an deflector surface is arranged spaced away from the guide surface towards the first wire emitter electrode defining a deflector gap between the guide surface and the deflector 25 surface seen in the plane perpendicular to the first wire longitudinal axis for deflecting the particle in the plane perpendicular to the first wire longitudinal axis.

This is advantageous as it mechanically assists the guiding surface and the electrostatic forces to guide the charged particles around the first wire emitter electrode and the first longitudinal bar.

30 In an embodiment of the particle catch arrangement according to the invention, the surface comprises a protruding deflector having a protruding deflector surface for mechanically boosting the particle flow such that it follows the looped trajectory. The protruding deflector protrudes in a direction towards the first wire emitter electrode.

This is advantageous as it allows for a stable looped trajectory due to the 35 mechanically boosting by the protruding deflector.

Preferably, the protruding deflector is curved such that it follows a shape of a desired shape of the looped trajectory.

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In a further embodiment, the protruding deflector surface is covered with a substantially reflective material that reflects ultraviolet radiation received from the first wire emitter electrode.

This is advantageous as it results in decomposition of polluted particles as a result of 5 the received ultraviolet radiation. The ultraviolet radiation is released as a by-product from the first wire emitter during corona discharging (ionizing air molecules). In particular, it decomposes hydrocarbon particles, more in particular aromatic hydrocarbon particles.

In an even further embodiment, a shape of the protruding deflector is such that the reflected ultraviolet radiation is directed towards the looped trajectory.

10 This is advantageous as it allows for a concentration of ultraviolet radiation towards an area where there are relatively many particles, being the looped trajectory. This increases efficiency.

In an even further embodiment, the protruding deflector surface is covered with a catalyst material. The catalyst material is activated by ultraviolet radiation that is preferably 15 received from the first wire emitter electrode.

This is advantageous as is allows for capturing and interception of particles that react as a result of contacting the catalyst. For example, the catalyst material is a titan oxide material. When activated by ultraviolet radiation the catalyst material results in converting a gas, such as nitrogen oxide into an aerosol. The aerosol is a particle that eventually can be 20 moved away by the particle flow and collected by a collector.

In an embodiment of the particle catch arrangement according the invention, the particle catch arrangement further comprises a liquid generator for providing a liquid to the particle flow and a liquid drain for collecting the liquid from the particle flow.

This is advantageous as it allows for humidifying the particle flow resulting in easily 25 capturing and intercepting polluted particle from the particle flow. The liquid, such as water and/or dew is collected by the liquid drain.

In particular, the liquid generator is provided such that is above the particle flow and the liquid drain is provided such that it is below the particle flow. Gravity simply lets the liquid go through the particle flow from the liquid generator into the liquid drain.

30 In an embodiment according to the invention a particle catch assembly comprises at least one particle catch arrangement according to the invention. A first particle catch arrangement is arranged parallel to a second particle catch arrangement such that respective wire emitter electrodes are at least partly substantially parallel.

This is advantageous as series connection or circuit allows for an increase of 35 capturing and/or interception capacity.

Preferably, the respective guide surface of the particle catch arrangements are integral.

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In another preference, the respective wire emitter electrodes are charged by a single voltage generator and/or power supply. This simplifies the particle catch assembly.

The invention also relates to a particle catch device according to claim 24.

5 Particle catch devices are known in the prior art, for example they are arranged beside open roads wherein they define an electrostatic field over the road. The electrostatic field attracts ionized particles towards a first collector surface. Ionized particle collide with polluted air molecules and/or particles.

Such a particle device is known from W02007/100254 which shows a particle catch 10 arrangement comprising positively charged antenna like objects that locally ionize air and negatively charged collector plates that attract ionized particles and collects them. The positively charged antenna and the negatively charged plates generate the electrostatic field above the road, such that smut, fine dust and exhaust gas particles are removed from an area above the road where the electrostatic field is generated.

15 Drawback of this particle catch arrangement is that only relatively large polluted particles are removed. The ionized particles only collide with particles that are sufficiently large. The larger the polluted particle the larger the chance that a moving ionized particle collides with polluted particle.

Moreover, a relative large electrostatic field must be generated to filter the polluted 20 air. The required relative large electrostatic field results in relative large energy required and/or relative large collector plates. This results in a negative impact on environmental issues such as visual pollution and/or energy usage.

25 In particular it is an object of the present invention to provide a particle catch arrangement that is able to remove relatively small polluted particles and/or molecules from polluted air.

The object is achieved by a particle catch device according to claim 24. The particle catch device is suitable for removing particles from a polluted particle flow. The particle 30 catch device in particular comprises a fist longitudinal bar according to the invention. It further comprises a first wire emitter electrode for locally ionizing particles having a first wire longitudinal axis. The first wire emitter electrode has a first wire longitudinally axis. The particle catch device also comprises a guide surface spaced apart parallel from the first wire longitudinal axis for guiding a particle flow in a plane perpendicular with respect to the first 35 wire longitudinal axis, in which the guide surface is charged with a different electrostatic charge compared to the first wire emitter electrode for generating an electrostatic force on - 12- the ionized particles in a direction from the first wire emitter electrode towards the guide surface.

The guide surface is arranged with a boost deflector having a starting point and an ending point seen in a plane perpendicular to the first wire longitudinal axis. The boost 5 deflector is suitable for mechanically boosting the particle flow in the plane perpendicular to the first wire longitudinal axis and is suitable for boosting the particle flow such that the particle follows at least partly a looped trajectory around the first wire emitter electrode.

By mechanically boosting at least a part of the particle flow following a looped trajectory around the first wire emitter electrode results in a scavenging effect that not only 10 generates the looped trajectory but also captures small polluted air particles and/or molecules. Here, the boosting is particularly generated mechanically by the guide surface having a boost deflector. The boost deflector can for example be a recess in the guide surface, but alternatively a protrusion.

In an alternative, the boosting is additionally generated electrically by the first 15 longitudinal bar according to the invention.

In a further embodiment the boost deflector has a shape that is substantially equal to a shape of the looped trajectory.

By mechanically shaping the booster deflector having the same shape as a desired looped trajectory, results in a stable looped trajectory.

20 In a further embodiment the first wire emitter electrode is arranged substantially centred with respect to the starting point and the ending point.

This allows for a stable looped trajectory.

The invention also relates to a method for removing particles from polluted air 25 according to claim 27. The method comprises the step of locally ionizing air by means of charging at least one wire emitter electrode having a longitudinal axis.

The method comprises the step of generating a particle flow by supplying a differently charged guide surface spaced away parallel from the at least one wire emitter electrode in a first direction perpendicular to the longitudinal axis for providing a first 30 electrostatic force on ionized particles from the first wire emitter electrode towards the guide surface resulting in the particle flow following a trajectory from the first emitter electrode towards the guide surface.

The method further comprises the step of mechanically guiding the particle flow in a guiding direction substantially lying in a plane perpendicular to the longitudinal axis by 35 means of extending the guide surface along the guiding direction.

The method further comprises the step of boosting the particle flow in a plane perpendicular to the longitudinal axis. The boosting is provided by means of providing a - 13- longitudinal bar spaced apart parallel from the at least one wire emitter and the guide surface. The longitudinal bar has a different electrostatic charge compared to the at least one wire emitter electrode for providing a second electrostatic force on the ionized particles from the at least one wire emitter electrode towards the longitudinal bar. This is suitable for 5 electrically boosting the particle flow such that the particle flow follows at least partly a looped trajectory around the at least one wire emitter electrode and the longitudinal bar substantially seen in a plane perpendicular to the wire longitudinal axis.

The boosting is alternatively provided by, or additionally provided by means of arranging the guide surface with a deflector recess. The deflector recess has a starting point 10 and an ending point seen in the plane perpendicular to the first wire longitudinal axis. The deflector recess is suitable for mechanically boosting the particle flow in the plane perpendicular to the first wire longitudinal axis. The first wire emitter electrode is arranged substantially centred with respect to the starting point and the ending point for mechanically boosting the particle flow such that the particle follows at least partly a looped trajectory 15 around the first wire emitter electrode.

These and other aspect of the invention will be more readily appreciated as the same becomes better understood by reference to the following detailed description and considered in connection with the accompanying drawings in which like reference symbols 20 designate like parts.

Figure 1 shows a perspective view of a first embodiment of the invention; figure 2a shows a side view of the first embodiment of the invention; figure 2b shows a side view of a further embodiment to the first embodiment; 25 figure 3 shows a perspective view of an alternative embodiment to the first embodiment; figure 4a shows a side view of the alternative embodiment; figure 4b shows a side view of a further embodiment of the alternative embodiment; figure 5 shows a second further embodiment to the first embodiment of the invention; 30 figure 6 shows a graphical representation concerning the second further embodiment; figure 7 shows a perspective view of a first alternative embodiment of the invention; figure 8 shows a perspective view of a second alternative embodiment of the invention.

35 figure 9a shows a side view of a second embodiment of the invention; figure 9b shows a perspective view of the second embodiment; - 14-

Figure 1 shows a perspective view of a particle catch arrangement 1 according to a first embodiment of the invention. The particle catch arrangement 1 comprises a support structure 2 having a first end 4a and a second end 4b. Here, the support structure comprises a first structural element 6a and a second structural element 6b at the first end 4a and the 5 second end 4b respectively. The first structural element 6a and the second structural element 6b are arranged substantially vertical with respect to a ground plane. The particle catch arrangement 1 further comprises a charged fist wire emitter electrode 7 for locally ionizing particles. The first wire emitter electrode 7a is held in tension by the support structure 2 between the first end 4a and the second end 4b. The first wire emitter electrode 10 7a is elongated and has a first wire longitudinal axis X1. A first auxiliary bar 12a and a second auxiliary bar 12b are arranged to the first- and second structural elements 6a, 6b respectively, in which the auxiliary bars 12a, 12b are provided with a first- and a second isolator 10a, 10b. The first wire emitter electrode 7a is held in tension via the isolators 10a, 10b in which the isolators 10a, 10b electrically isolate the first wire emitter electrode 7a from 15 the support structure 2. The auxiliary bars 12a, 12b are arranged substantially horizontally with respect to the ground plane. This means that the auxiliary bars 12a, 12b are provided at substantially a same height to the vertical structural elements 6a, 6b. The first wire emitter electrode 7a further comprises a guide surface 15 for guiding at least a part of a particle flow S substantially in a plane perpendicular to the first wire longitudinal axis X1.

20 Figure 2a shows the particle catch arrangement 1 in the plane perpendicular to the first wire longitudinal axis X1. The guide surface 15 is spaced away parallel from the first wire emitter electrode 7a in a first direction Z1 perpendicular with respect to the first wire longitudinal axis X1. The first direction Z1 is aligned with a smallest distance between the first wire emitter electrode 7a and the guide surface 15. The guide surface 15 has a different 25 electrostatic charge with respect to the first wire emitter electrode 7a for providing a first electrostatic force on the ionized particles. The first electrostatic force is exerted on the ionized particles from the first wire emitter electrode towards the guide surface 15. The first electrostatic force results from a corresponding first electrostatic field 30a generated from the first wire emitter electrode 7a towards the guide surface 15. The direction of the first 30 electrostatic field 30a and the corresponding first electrostatic force is substantially equal to the first direction. At least, at a location where a strongest first electrostatic field and corresponding strongest first electrostatic force occurs the respective field and force have a direction that is substantially equal to the first direction.

The support structure 2 comprises a first longitudinal bar 20a spaced away parallel 35 from the first wire emitter electrode 7a in a second direction Z2 perpendicular with respect to the first wire longitudinal axis X1. The second direction Z2 comprises a component that is opposite to the first direction Z1. The second direction Z2 also comprises a component that - 15- is perpendicular to the first direction Z1. This means, that the first wire emitter electrode 7a is provided substantially between the guide surface 15 and the first longitudinal bar 20a.

The first longitudinal bar 20a has a different electrostatic charge with respect to the first wire emitter electrode 7a and is suitable for providing a second electrostatic force, 5 resulting form a second electrostatic field 30b, on the ionized particles. The second electrostatic force is exerted from the first wire emitter electrode towards the first longitudinal bar 20a. The first longitudinal bar 20a is provided such that the second electrostatic force is suitable for boosting the particle flow S such that the particle flow S at least partly follows a looped trajectory T1 around the first wire emitter electrode 7a and the first longitudinal bar 10 20a, seen in the plane perpendicular to the first wire longitudinal axis X1.

As best seen in figure 2a, the first electrostatic field 30a creates the first electrostatic force on ionized particles from the first wire emitter electrode 7a towards the guide surface 15. The second electrostatic field 30b generates the second electrostatic force on ionized particles from the second wire emitter electrode 7 towards the first longitudinal bar 20a. A 15 trajectory of the particle flow S is indicated by means of a dashed line indicated by S.

A travelling particle in the particle flow S starts at a start location away from the guide surface 15, first wire emitter electrode 7a and the first longitudinal bar 20a and flows towards the guide surface 15. The travelling particle is captured by the first electrostatic field 30a and the first electrostatic force moves the travelling particle to the guide surface 15 until it hits the 20 guide surface 15. Because a component of the second direction being perpendicular with respect to the first direction, the travelling particle shall boost, in other words deflect, in this perpendicular direction due to scavenging. Ionized particles in the second electrostatic field 30b move in the second direction and indirectly draws the travelling particle that surrounds these ionized particles in substantially the same second direction. Drawing the travelling 25 particle is named scavenging.

Therefore, the travelling particle flows from the guide surface 15 towards the first longitudinal bar 20a. It shall not hit the first longitudinal bar 20a, but shall curve around the first longitudinal bar 20a as a result of scavenging effects originated by the particle flow S that flows from the start location towards the guide surface 15.

30 The presence of the first longitudinal bar 20a generates the second electrostatic field 30b that electrically boosts the travelling particle.

This way the particle flow S comprises at least partly a trajectory that loops around the first wire emitter electrode 7a and the first longitudinal bar 20a.

35 Figure 2b shows a further embodiment of the invention, wherein boosting of the particle flow S is additionally generated mechanically by means of a first deflector surface 25a.

- 16-

The first deflector surface 25a is arranged spaced away from the guide surface 15. The first deflector surface 25a in this case has a curved member. Spaced away here means that a first deflector longitudinal axis is spaced away from the guide surface 15. Seen in this plane perpendicular to the first wire longitudinal axis X1 a first deflector gap 26a is defined.

5 When the particle flow S hits the first deflector surface 25a at least a part follows a trajectory through the first deflector gap 26a. At least another part follows a trajectory through a space opposite from the first deflector gap 26a, preferably oriented in a direction towards the first longitudinal bar 20a. This way the particle flow S is at least partly boosted mechanically towards the first longitudinal bar 20a and at least partly boosted along the guide surface 15.

10 The former results in a stronger first looped trajectory T1. The latter results in collecting more polluted particles by the guide surface 15.

Preferably, the first deflector surface 25a is provided at said location by the support structure 2.

Preferably, a first collector 18a is arranged near the guide surface 15 for receiving 15 particles from the particle flow S. Preferably, the first collector 18a is charged with a electrostatic charge that is opposite to the electrostatic charge of the first wire emitter electrode 7a. This is advantageous as the particle flow S is drawn towards the first collector 18a. Preferably, the first collector 18a is arranged to the guide surface 15 as shown in fig.

2a. Further preferably, the first collector 18a is arranged near the first deflector gap 26a 20 where the particle flow S leaves the first deflector gap 26a. The particle flow S is then at least partly boosted mechanically by the first deflector surface 25a towards the first collector 18a.

For example, the first collector 18a is made from a material being an electret.

25 Figure 3 shows a particular advantageous further embodiment wherein the particle catch arrangement 1 further comprises a second wire emitter electrode 7b. The second wire emitter electrode 7b has a second wire longitudinal axis X2 and is held in tension between the first end and the second end of the support structure 2 via third- and fourth isolators 10c, 10d. The second wire emitter electrode 7b is is spaced apart parallel from the first wire 30 emitter electrode 7a defining a wire gap 28 between the first- and second wire emitter electrode 7a, 7b. The particle flow S follows at least partly a trajectory through the wire gap 28 towards the guide surface 15. The guide surface 15 is spaced away parallel from the second wire emitter electrode 7b in a third direction Z3 best shown in figure 4a.

In figure 4a it is further shown that the third direction Z3 is aligned with and along a 35 smallest distance between the second wire emitter electrode 7b and the guide surface 15.

The guide surface 15 has a different electrostatic charge compared to the second wire emitter electrode 7b and is suitable for providing a third electrostatic force on the - 17- ionized particles. The third electrostatic force results from a third electrostatic field 30c generated from the second wire emitter electrode 7b towards the guide surface 15.

The third electrostatic field 30c results in the particle flow S at least partly follows a trajectory from between the wire gap 28 towards the guide surface 15 in addition to the first 5 electrostatic field 30a.

A second longitudinal bar 20b is arranged on the support structure 2 and is spaced away parallel from the second wire emitter electrode 7b in a fourth direction Z4 perpendicular with respect to the second wire longitudinal axis X2. The fourth direction Z4 has a component that is opposite to the third direction Z3. The fourth direction Z4 also 10 comprises a component that is perpendicular to the third direction Z3. Preferably, here the component of the fourth direction Z4 perpendicular to the third direction Z3 is opposite and aligned with the component of the second direction Z2 perpendicular to the first direction Z1. This is advantageous as the boosting by the first longitudinal bar 20a is synergetically added to the boosting by the second longitudinal bar 20b. Having the two longitudinal bars 20a, 15 20b arranged like this synergetically results in working together to generate a first looped trajectory T1 and a second looped trajectory T2 that are stronger compared to having only one of the two longitudinal bars 20a, 20b.

A fourth electrostatic force results from a fourth electrostatic field 30d resulting from the second longitudinal bar 20b having a different electrostatic charge compared with the 20 second wire emitter electrode 7b. As the fourth electrostatic force substantially is in the fourth direction Z4 and therefore comprises a component that is perpendicular to the third direction Z3, the second longitudinal bar 20b boosts the particle flow S such that the particle flow S at least partly follows the second looped trajectory T2 around the second wire emitter electrode 7b and the second longitudinal bar 20b.

25 Seen in figure 4a, being in a plane perpendicular to the second wire longitudinal axis X2, the first looped trajectory T1 is depicting at least a part of the particle flow S in clockwise direction. The second looped trajectory T2 is in a different rotational direction and is depicting at least a part of the particle flow S in counter clockwise direction.

Summarized, the arrangement of the second longitudinal bar 20b, second wire 30 emitter electrode 7b and guide surface 15 has the same advantages as the arrangement of the first longitudinal bar 20a, first wire emitter electrode 7a and guide surface 15. However, having them both arranged substantially symmetrical to each other in a plane perpendicular to the guide surface 15 and parallel between the first wire longitudinal axis X1 and the second wire longitudinal axis X2 results in a synergetic effect. A strength of the first looped 35 trajectory T1 and the second looped trajectory T2 is stronger when they are combined than when they are arranged separately. This results from the second direction Z2 has a - 18- component opposite and aligned with respect to the fourth direction Z4 and the first direction Z1 and third direction Z3 are substantially pointing in a same direction, although not aligned.

Figure 4b, shows a further symmetrical arrangement of a second deflector surface 25b and second deflector gap 26b with respect to the first deflector surface 25a and the first 5 deflector gap 26a. Also a second collector 18b is symmetrically arranged with respect to the first collector 18a. The same advantages apply for the second case indicated by a letter “b” as well as for the first case indicated by a letter “a”.

Figure 5 shows a further embodiment to the first embodiment for the case of two wire 10 emitter electrodes 7a, 7b and two longitudinal bars 20a, 20b. Shown are the first wire emitter electrode 7a and the second wire emitter electrode 7b and the first longitudinal bar 20a and the second longitudinal bar 20b. Not shown, but present is the guide surface 15 according to the invention.

The particle catch arrangement 1 further comprises a first voltage generator 40a for 15 providing a voltage, in particular a high voltage, to the first wire emitter electrode 7a and the second wire emitter electrode 7b. Here, only the first voltage generator 40a supplies the high voltage to the wire emitter electrodes 7a, 7b and not the longitudinal bars 20a, 20b. The first voltage generator 40a is configured to receive a voltage setting signal P1. Based on a value of the voltage setting signal P1, the first voltage generator 40a provides a corresponding 20 voltage to the first wire emitter electrode 7a.

Further shown is a control unit 35. The control unit 35 is configured to provide the voltage setting signal P1. In general, the control unit 35 give a value to the voltage setting signal P1 such the voltage provided to the first wire emitter electrode 7b remains constant.

The first longitudinal bar 20a is provided with a first bar electrode, which is isolated in 25 the support structure 2. By having the first longitudinal bar 20a provide with the first bar electrode it allows to easily charge the first longitudinal bar 20a. In an alternative, the first longitudinal bar 20a is the same as the first bar electrode. This is advantageous, as the first bar electrode is a accurately chargeable surface as well as a structural member giving support to the particle catch arrangement 1.

30 As described above, a first electrical field 30a is generated from the first wire emitter electrode 7a towards the first longitudinal bar 20a. This results in that ions hit the first bar electrode such that a current is generated in the first bar electrode. This current is measured by means of a first current sensor 37a. The first current sensor 37a is configured to provide a first current measurement signal P2 representative for the current in the first longitudinal 35 bar 20a.

-19-

The first current measurement signal P2 is not constant with time, but in general shall vary as indicated in figure 6. In this diagram the first current measurement signal P2 on the vertical diagram axis is displayed as function of time on the horizontal diagram axis.

On the far left side of the diagram an initial value of the first current measurement 5 signal P2 is shown. The first current measurement signal P2 shall gradually increase. This is a result of the dispersion of small metal particles from the first wire emitter electrode 7a, such that emitting of the first wire emitter electrode 7a increases resulting in more charged ions. With the first wire emitter electrode 7a getting thinner due to its dispersion of the small metal particles a risk of breaking of the first wire emitter electrode 7a increases.

10 To reduce this risk and to increase the duration of life of the first wire emitter electrode 7a, the control unit 35 is configured to receive the first current measurement signal P2 and control the voltage setting signal such that the first current measurement signal P2 remains substantially the same as the initial value of the first current measurement signal P2.

15 Moreover, the increase of the first current measurement signal P2, indicated by L1, is representative for a thickness of the first wire emitter electrode 7a and therefore the duration of life thereof. This information is particular useful to have an indication to a user about a need to precautionary maintenance.

As a result of particles in the first electrostatic field 30a, the first current measurement 20 signal P2 shall decrease as ions in the first electrostatic field 30a shall collide with these particles and be moved away into for example the first looped trajectory T1 due to scavenging.

Therefore a decrease of the first current measurement signal P2, indicated by L2, is representative for an amount of catching of particles. This information is particular useful to 25 have an indication to a user about an amount of captured particles. It easily gives information regarding the efficiency of the particle catch arrangement in terms of number of captured particles.

Further shown in figure 5 are a second current sensor 37b which is configured to provide a second current measurement signal P3 representative for the current in the first 30 wire emitter electrode 7a. Although not shown, it is particularly useful to provide the second current measurement signal P3 to the control unit 35. The control unit 35 is configured to receive the second current measurement signal P3. This is advantageous, as more control options are available increasing the duration of life of the particle catch arrangement 1.

Also further shown in figure 5 is a first voltage sensor 38a which is configured to 35 provide a first voltage measurement signal P4 representative for the voltage in the first wire emitter electrode 7a. Although not shown, it is particularly useful to provide the first voltage measurement signal P4 to the control unit 35. The control unit 35 is configured to receive the -20- first voltage measurement signal P4. This is advantageous, as more control options are available increasing the duration of life of the particle catch arrangement 1.

It is particular advantageous to provide a display (not shown) to the control unit 35. The control unit 35 is configured to display received signals and emitted voltages on the 5 display. For example the received signals and emitted voltage are displayed momentary and/or along a predetermined time span, such as seen in figure 6. This allows the user to take appropriate action, for example starting precautionary maintenance when needed.

Figure 7 shows an alternative embodiment of the invention. Shown are the first wire 10 emitter electrode 7a and the second emitter electrode 7b being arranged parallel with respect to each other and with respect to the guide surface 15 which here is displayed below the wire emitter electrodes 7a, 7b.

The guide surface 15 comprises a first protruding deflector 33a for mechanically boosting the particle flow S such that it at least partly follows a first looped trajectory T1 and 15 at least partly a second looped trajectory T2. The first protruding deflector 33a protrudes towards the wire emitter electrodes 7a, 7b. This is particularly advantageous as it not only mechanically boosts the particle flow S to follow the looped trajectories T1, T2 but also reduces external flow disturbances resulting from for example external wind and/or ventilation. These external flow disturbances may have an adverse effect on the particle flow 20 S following the looped trajectories T1, T2.

It is particularly advantageous to cover a surface 34 of the first protruding deflector 33a with a catalyst such as titan oxide. Due to the particle flow S following the looped trajectory T1, T2 there are multiple contact moments between the surface of the first protruding deflector 33a and the particle flow S. This particularly advantageous, as titan 25 oxide reacts with nitrogen oxides (NOx) into a less polluting aerosol, being an ionized particle, the aerosol is captured by the particle flow S and eventually collected and removed from the air. Activation of the catalyst is provided by ultraviolet radiation from the first wire emitter electrode 7a and/or the second wire emitter electrode 7b. In figure 7, it is shown that the second wire emitter electrode 7b is arranged nearest to the first protruding deflector 30 surface 34a. However, it is foreseen that the first protruding deflector surface 34a stretches out over a surface closer to the first wire emitter electrode 7a. Ultraviolet radiation is emitted as by-product during the corona gas discharge, being the ionization of the air molecules. A distance between the first protruding deflector 33a and the second wire emitter electrode 7b is such that sufficient ultraviolet radiation is received by the first protruding deflector surface 35 34a.

It is additionally advantageous to provide the first protruding deflector surface 34a with a reflection layer (not shown). This reflection layer is made from a material that reflects -21 - the ultraviolet radiation received from the second wire emitter electrode 7b. Reflecting the ultraviolet radiation between the first protruding deflector surface 34a and the second wire emitter electrode 7b results in an antiseptic action on the particle flow S that follows the second looped trajectory T2. As the second looped trajectory T2 is stably provided between 5 the first protruding deflector surface 34a and the second wire emitter electrode 7b, the antiseptic action results in the decomposition of polluted particles such as in particular hydrocarbons and more in particular aromatic hydrocarbons that are in the particle flow S. A direction of ultraviolet reflection is indicated by an arrow R1.

It is further advantageous to provide the guide surface with collectors comprising 10 protruding fibres 50a, 50b. First protruding fibres 50a are provided near the first wire emitter electrode 7a. The first protruding fibres 50a protrude from the guide surface 15 and are arranged such that the first wire emitter substantially is between the first protruding fibres 50 and the first protruding deflector surface 34a. The first protruding fibres 50 typically have a hair-shaped structure. Due to molecular forces, being Coulomb forces, the first protruding 15 fibres 50 collect larger polluted particles and remove them from the particle flow S that follows the first looped trajectory T1. Collection by means of fibres and resulting molecular forces is particular advantageous as a thickness of the fibres is dependent on a size of the polluted particles to be collected.

Correspondingly, collectors comprising second protruding fibres 50b are provided to 20 the guide surface near the second wire emitter electrode 7b.

It is furthermore advantageous to shape the first protruding deflector surface 34a such that ultraviolet radiation is directed towards the collectors, being the protruding fibres 50a, 50b. The collected particles, which are intercepted from the looped trajectory, are treated by the ultraviolet radiation which results in decomposition of these collected particles. 25 This in particular is advantageous for decomposing hydrocarbon particles, more in particular aromatic hydrocarbon particles.

In a further embodiment, the collectors comprise a first substrate 51a that is charged by a second voltage generator 40b. The first substrate 51a is arranged between the guide surface 15 and the first protruding fibres 50a. This is advantageous as a collection and 30 interception action of the respective collector is increased and also allows for the capturing and interception of suspended particles such as oil mist, haze and fog.

In an even further embodiment, a liquid is added to the first substrate 51a by a liquid generator (not shown). This allows for gas removal, such as ammoniac gas. The first protruding fibres 50a result in a capillary action and the humid atmosphere due to the liquid 35 results in the gas removal.

-22 -

When the applied voltage by the second voltage generator 40b is high enough, a fine fog is produced through electro spray, intercepting the gas to be removed on the first substrate 51b and which is eventually removed by a first drain 52a.

Correspondingly, collectors comprising a charged second substrate 52b are provided 5 to the guide surface 15. Also shown is a corresponding second drain 52b.

Figure 8 shows a particle catch assembly comprising three particle catch arrangements according to a first embodiment. Shown are six wire emitter electrodes 7a, 7b, 7c, 7d, 7e, 7f, being the first wire emitter electrode 7a, the second wire emitter electrode 7b, 10 a third wire emitter electrode 7c, a fourth wire emitter electrode 7d, a fifth wire emitter electrode 7e and a sixth wire emitter electrode 7d respectively. The wire emitter electrodes emitter electrodes 7a, 7b, 7c, 7d, 7e, 7f are charged by a single third voltage generator 40c, therefore the emitter electrodes 7a, 7b, 7c, 7d, 7e, 7f are electrically connected with each other. However, six isolator tubes 65a, 65b, 65c, 65d, 65e, 65f are provided around a 15 connection part between the emitter electrodes 7a, 7b, 7c, 7d, 7e, 7f. This is to electrically isolate the connection parts between the emitter electrodes 7a, 7b, 7c, 7d, 7e, 7f from the environment, such that only parallel arranged emitter electrodes 7a, 7b, 7c, 7d, 7e, 7f are present. This is advantageous for stably generating the six looped trajectories.

Further shown is a guide surface. The guide surface comprises four collectors each 20 comprising a substrate 51a, 51b, 51c, 51 d and protruding fibres 50a, 50b, 50c, 50d. The guide surface also comprises three protruding deflectors 33a, 33b, 33c each having a protruding deflector surface 34a, 34b, 34c.

Note, that the collectors and the protruding deflectors function as guide surface and in this embodiment the guide surface is interrupted. In an alternative, the guide surface is 25 formed integrally.

The particle catch assembly is arranged such that the emitter electrodes 7a, 7b, 7c, 7d, 7e, 7f are substantially vertically arranged and perpendicular with respect to a ground plane. The guide plane therefore is also perpendicular to the ground plane. In this embodiment the protruding deflectors 33a, 33b, 33c are elongated along their respective 30 longitudinal axis X10, X11, X12. The protruding deflector longitudinal axes X10, X11, X12 are perpendicular to the ground plane.

Above each of the protruding fibres 50a, 50b, 50c, 50d a liquid generator 60a, 60b, 60c, 60d is arranged to humidify and/or liquefy the protruding fibres 50a, 50b, 50c, 50d and clean them. Polluted particles are mixed with the liquid and the polluted liquid is captured by 35 funnel shaped drains 62a, 62b, 6c, 62d. The funnel shaped drains 62a, 62b, 6c, 62d are arranged below the protruding fibres 50a, 50b, 50c, 50d and below the liquid generators 60a, 60b, 60c, 60d.

-23- A single drainage tube 65 connects all the funnel shaped drains 62a, 62b, 6c, 62d and conveys the polluted liquid to a central point.

A single water supply tube 61 connects all the liquid generator 60a, 60b, 60c, 60d and supplies liquid from a central source.

5 This particle arrangements is particularly advantageous as it safely can filter a relatively large amount of air.

Finally, figure 9a and figure 9b show an embodiment of a second particle catch device 101 according to a second embodiment of the invention.

10 Figure 9a shows the particle catch device 101 in a side view. The particle catch device 101 is suitable for removing particles from a polluted particle flow S2. The particle catch device 101 comprises a first wire emitter electrode 107a for locally ionizing particles having a first wire longitudinal axis.

A guide surface 115 is spaced apart parallel from the first wire longitudinal axis 107a 15 for guiding a particle flow S2 in a plane perpendicular with respect to the first wire longitudinal axis. The guide surface 115 is charged with a different electrostatic charge compared to the first wire emitter electrode 107a for generating an electrostatic force on the ionized particles in a direction from the first wire emitter electrode 107a towards the guide surface 115.

20 The guide surface 115 is arranged with a first boost deflector 70a having a starting point 71 and an ending point 72 seen in a plane perpendicular to the first wire longitudinal axis for mechanically boosting the particle flow S2. The boost deflector 70a is shaped such that the particle flow S2 follows at least partly a first looped trajectory T101 around the first wire emitter electrode 107a.

25 Here, the first boost deflector 70a is shaped substantially the same as the first looped trajectory T101.

Also shown is a second wire emitter electrode 107b which is spaced away from the first wire emitter electrode 107a. This second wire emitter electrode 107b cooperates with a second boost deflector 70b and boosts at least a part of the particle flow S2 into a partly 30 curved trajectory. In particular, the second wire emitter electrode 107b is charged with a lower voltage than the first wire emitter electrode 107a, such that a full looped trajectory does not occur around the second wire emitter electrode 107b.

Also shown is a third wire emitter electrode 107c spaced away parallel to a third boost deflector 70c for generating a second looped trajectory T102.

35 A fourth wire emitter electrode 107d is spaced away parallel from the third wire emitter electrode 107c and cooperates with a fourth boost deflector 70d and boosts at least a part of the particle flow S2 into a partly curved trajectory. In particular, the fourth wire -24 - emitter electrode 107d is charged with a lower voltage than the third wire emitter electrode 107c, such that a full looped trajectory does not occur around the fourth wire emitter electrode 107d.

A part of the guide surface between the first boost deflector and fourth boost 5 deflector is covered with titanium oxide to filter nitrogen oxide gas from the air flow.

The particle catch arrangement and/or device according to the invention is not limited to the described embodiments. Any combination of the described embodiments is possible and foreseen.

10 In an embodiment of the particle catch arrangement, there is at least one wire emitter electrode, in particular three, four, five or six spaced parallel to each other.

In an embodiment, the length of the wire emitter electrode is substantially smaller and/or equal to 10m, 6m or 3m. The smallest distance to the guide surface is respectively substantially smaller than 1 m, 0.5m or 0.25m.

15 In an embodiment, the voltage applied to at least one wire emitter electrode is 1.5-50 kV, more in particular 2-45 kV.

In an embodiment, at least one generated electrostatic field is at least 0.2 kV/m more in particular in the range of 0.2-50 kV/m.

In an alternative embodiment the longitudinal bar has a constant thickness or a 20 varying thickness along the length. It may be a straight longitudinal bar or a bend and/or curved longitudinal bar.

In an alternative embodiment the wire emitter electrode has a constant thickness or has a varying thickness along the length. The wire is foreseen to be flexible or non flexible or even be a thin bar like electrode. In general it is an elongated corona discharger.

25

As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which can be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis 30 for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriate detailed structure. Further, the terms and phrases used herein are not intended to be limiting, but rather, to provide an understandable description of the invention.

The terms “a” or “an”, as used herein, are defined as one or more than one. The term 35 “ plurality”, as used herein, is defined as two or more than two. The term “another”, as used herein, is defined as at least a second or more. The terms “including” and/or “having”, as used herein, are defined as comprising (i.e. open language, not excluding other elements or -25- steps). Any reference signs in the claims should not be construed as limiting the scope of the claims of the invention.

The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to 5 advantage.

Claims

A particle capture device for removing particles from a contaminated particle stream, comprising: - a support structure comprising a first end and a second end; - a charged first emitting electrode wire comprising a longitudinal axis of the first wire for locally ionizing particles, wherein the first emitting electrode wire is kept stressed by the support structure between the first end and the second end via insulators which isolate the first charged electrode wire relative to the support structure; - a guiding surface for guiding at least a part of the particle flow substantially in a plane perpendicular to the longitudinal axis of the first wire, the guiding surface being spaced parallel to the first emitting electrode wire in a first direction perpendicular to the longitudinal axis of the first wire, the guide surface comprising a different electrostatic charge relative to the first emitting electrode wire to provide a first electrostatic force on the ionized particles of the first emitting electrode wire to the guide surface with the characterized in that the support structure comprises a first longitudinal rod which is spaced parallel to the first emitting electrode wire in a second direction perpendicular to the longitudinal axis of the first wire, the second direction being a component t has opposite to the first direction and has a component that is perpendicular to the first direction, the first longitudinal rod having a different electrostatic charge with respect to the first emitting electrode wire for providing a second electrostatic force on the ionized particles from the first emitting wire to the first longitudinal rod for driving the particle flow such that the particle flow follows at least in part a loop-like path around the first emitting electrode wire and the first longitudinal rod substantially in the plane perpendicular to the first emitting electrode wire. 30

A particle capture device according to any of the preceding claims, wherein a first gap is provided between the first emitting electrode wire and the guide surface and a second gap is provided between the guide surface and the first longitudinal rod 35 to allow a particle flow follows a loop-like path around the first emitting electrode wire and the first longitudinal rod in the plane perpendicular to the longitudinal axis of the first wire.

A particle capture device according to claim 1, comprising: 5. a charged second emitting electrode wire comprising a longitudinal axis of the second particle ionizing wire, wherein the second emitting electrode wire is held tensioned by the support structure between the first end and the second end via insulators isolating the second charged electrode wire from the support structure, the second emitting electrode wire being placed parallel to the first emitting electrode wire thereby defining a wire opening resulting in the particle flow following a path through the wire opening to the guide surface, the guide surface being spaced parallel to the second emitting electrode wire in a third direction perpendicular to the longitudinal axis of the second wire, the guide surface being different comprises an electrostatic charge with respect to the second emitting electrode wire for providing a third electrostatic force on the ionized particles of the second emitting electrode wire to the guide surface, the support structure comprising a second longitudinal rod disposed parallel to each other relative to the second emitting electrode wire in a fourth direction perpendicular to the longitudinal axis of the second wire, wherein the fourth direction has a component that is opposite to the third direction and has a component that is perpendicular to the third direction, the second longitudinal rod has a different electrostatic charge relative to the second emitting electrode wire to provide a fourth electrostatic force on the ionized particles from the second emitting wire to the second longitudinal rod for driving the particle st flow such that the particle flow follows at least in part a loop-like path around the second emitting electrode wire and the second longitudinal rod substantially in the plane perpendicular to the second emitting electrode wire. Particulate capture apparatus according to the preceding claim, wherein a third gap is provided between the second emitting electrode wire and the guide surface and a fourth gap is provided between the guide surface and the second longitudinal rod to allow a particle flow to be looped trajectory follows around the second emitting electrode wire and the second longitudinal rod in the plane perpendicular to the longitudinal axis of the second wire.

A particle-catching device according to any of claims 3-4, wherein a smallest distance between the first emitting electrode wire and the guide surface and a smallest distance between the second emitting electrode wire and the guide surface are substantially equal.

6. Particle capture device according to any of the preceding claims, wherein the particle capture device comprises a first collector disposed near the guide surface for receiving particles from the particle flow.

7. Particle trapping device according to claim 6, wherein the first collector comprises a charged substrate for catching particles from the particle flow by means of molecular forces.

8. Particle trapping device according to any of claims 6-7, wherein the first collector comprises protruding fibers for catching particles from the particle flow by means of molecular forces.

9. Particle capture device according to any of the preceding claims, wherein the first emitting electrode wire comprises a longitudinal spaced sharp discharge means for locally ionizing particles, wherein at least one sharp discharge means is provided in a plane perpendicular to of the longitudinal axis of the first wire comprising the particle flow that at least partially follows the loop-like path.

10. Particulate capture device according to any of the preceding claims, wherein the first emitting electrode wire is positively charged by applying a positive voltage, the first longitudinal rod being charged with a voltage lower than the voltage of the first emitting electrode wire, and the guide surface is charged with a voltage lower than the voltage of the first longitudinal bar. 35

The device of any preceding claim, wherein a smallest distance between the guide surface and the first emitting electrode wire is greater than or equal to a smallest distance between the first longitudinal rod and the first emitting electrode wire.

A particle-catching device according to any of the preceding claims, wherein a smallest distance between the guide surface and the first emitting electrode wire is 30 cm, the smallest distance between the first longitudinal rod and the first emitting electrode wire being 30 cm, and the length of the first emitting electrode wire is 6 m.

Particulate capture apparatus according to any of the preceding claims, further comprising: - at least one generator configured to receive a voltage setting signal and configured to provide a voltage to the first emitting electrode wire and / or the first longitudinal bar representative of the voltage setting signal; a control unit configured to provide the voltage setting signal that is dependent on the electrostatic charge of the first emitting electrode wire, and / or the electrostatic charge of the conducting surface, and / or a smallest distance between the first emitting electrode wire and the conducting surface, and / or a smallest distance between the first emitting electrode wire and the first longitudinal rod.

14. The particle capture device according to claim 13, wherein the particle capture device further comprises at least one voltage sensor for providing a voltage measurement signal representative of a voltage in the first longitudinal rod, and / or a voltage in the first emitting electrode wire, and / or a voltage in the conductive surface, the control unit being configured to receive the voltage measurement signal. 30

A particle capture device according to any of claims 13-14, wherein the particle capture device further comprises at least one flow sensor for providing a flow measurement signal representative of a flow in the first longitudinal bar, and / or a current 35 in the first emitting electrode wire, and / or a current in the guide surface, the control unit being configured to receive the current measurement signal. -30-

A particle capture device according to any of claims 13-15, wherein the control unit is configured to provide a voltage setting signal representative of the second electrostatic force that is greater than the first electrostatic force. 5

17. A particle-catching device according to any one of the preceding claims, wherein a deflection surface is disposed at a distance from the guide surface towards the first emitting electrode wire, wherein a deflection aperture is defined between the guide surface and the deflection surface viewed in the plane parallel to the first emitting electrode wire for deflecting the particle in the plane perpendicular to the longitudinal axis of the first wire.

18. A particle-catching device according to any one of the preceding claims, wherein the guide surface comprises a protruding deflection device which comprises a protruding deflection surface for mechanically driving the particle flow such that it follows the loop-like trajectory.

19. The particle capture device of claim 18, wherein the protruding deflection surface is covered with a substantially reflective material that reflects ultraviolet radiation received from the first emitting electrode wire.

20. The particle capture device of claim 19, wherein a shape of the protruding deflection device is such that the reflected ultraviolet radiation is directed toward the loop-like trajectory.

A particle capture device according to any of claims 18-20, wherein the protruding deflection surface is covered with a catalyst material.

A particle capture device according to any one of the preceding claims, wherein the particle capture device further comprises: a fluid generator for providing fluid to the particle flow; a liquid discharge for collecting the liquid from the particle flow. 35

A particle capture assembly, comprising at least one particle capture device according to any of the preceding claims, wherein a first particle capture device is arranged in parallel with a second capture device of particles such that respective emitting electrode wires are at least partially substantially parallel.

A particle capture device for removing particles from a contaminated particle flow, preferably comprising a first longitudinal rod according to any of the preceding claims and further comprising: a first emitting electrode wire for locally ionizing particles comprising a longitudinal axis of the first thread; 10. a guide surface that is spaced parallel to the longitudinal axis of the first wire for guiding a particle flow in a plane perpendicular to the longitudinal axis of the first wire, the guide surface being charged with a different electrostatic charge relative to the first emitting electrode wire for generating an electrostatic force on the ionized particles in a direction from the first emitting electrode wire to the guide surface, characterized in that the guide surface is provided with a driving deflection device comprising a starting point and a starting point end point seen in a plane perpendicular to the longitudinal axis of the first wire for mechanically driving the particle flow in the plane perpendicular to the longitudinal axis of the first wire for driving the particle flow such that the particle flow is at least gede finally follows a loop-like path around the first emitting electrode wire. 25

The particle capture apparatus according to claim 24, wherein the driving deflection device has a shape that is substantially equal to a shape of the loop-like trajectory.

A particle capture device according to any of claims 24-25, wherein the first emitting electrode wire is disposed substantially in the center of the start point and the end point.

27. A method for removing particles from contaminated air, comprising the steps of: locally ionizing air by charging at least one emitting electrode wire that has a longitudinal axis; Generating a particle flow by providing a differently charged conductive surface that is spaced in parallel from the at least one emitting electrode wire in a first direction perpendicular to the longitudinal axis to provide a first electrostatic force on the ionized particles from the first emitting electrode wire toward the guide surface; mechanically guiding the particle flow in a guide direction that is substantially located in a plane perpendicular to the longitudinal axis by extending the guide surface along the guide direction, characterized in that the method further comprises the step of driving the particle flow in a plane perpendicular to the longitudinal axis by: providing a longitudinal rod spaced from the at least one emitting electrode wire and the guide surface, the longitudinal rod having a different electrostatic charge with respect to the at least one emitting electrode wire for providing a second electrostatic force on the ionized particles of the at least one emitting electrode wire toward the longitudinal rod for electrostatically driving the particle flow such that the particle flow at least partially loops tr aject follows around the at least one emitting electrode wire and the longitudinal rod substantially in a plane perpendicular to the longitudinal axis of the wire and / or by means of: - providing the guide surface with a deflection recess having a starting point and an end point has seen in a plane perpendicular to the longitudinal axis of the first wire for mechanically driving the particle flow in the plane perpendicular to the longitudinal axis of the first wire and wherein the first emitting electrode wire is substantially in the center of the starting point and the end point is provided for mechanically driving the particle flow such that the particle flow at least partially follows a loop-like path around the first emitting electrode wire.