EP4230299A1 - Filtre d'air de cabine avec polarisation - Google Patents

Filtre d'air de cabine avec polarisation Download PDF

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Publication number
EP4230299A1
EP4230299A1 EP22157505.3A EP22157505A EP4230299A1 EP 4230299 A1 EP4230299 A1 EP 4230299A1 EP 22157505 A EP22157505 A EP 22157505A EP 4230299 A1 EP4230299 A1 EP 4230299A1
Authority
EP
European Patent Office
Prior art keywords
gas filter
gas
filter
contact
housing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP22157505.3A
Other languages
German (de)
English (en)
Inventor
Stefan Robert
Andreas Borchard
Martin Rölver
Tom Klaver
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hengst SE and Co KG
Original Assignee
Hengst SE and Co KG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hengst SE and Co KG filed Critical Hengst SE and Co KG
Priority to EP22157505.3A priority Critical patent/EP4230299A1/fr
Priority to EP22182008.7A priority patent/EP4230298A1/fr
Priority to PCT/EP2023/053663 priority patent/WO2023156403A1/fr
Priority to PCT/EP2023/053664 priority patent/WO2023156404A1/fr
Publication of EP4230299A1 publication Critical patent/EP4230299A1/fr
Pending legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03C3/00—Separating dispersed particles from gases or vapour, e.g. air, by electrostatic effect
    • B03C3/02—Plant or installations having external electricity supply
    • B03C3/04—Plant or installations having external electricity supply dry type
    • B03C3/14—Plant or installations having external electricity supply dry type characterised by the additional use of mechanical effects, e.g. gravity
    • B03C3/155—Filtration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03C3/00—Separating dispersed particles from gases or vapour, e.g. air, by electrostatic effect
    • B03C3/02—Plant or installations having external electricity supply
    • B03C3/04—Plant or installations having external electricity supply dry type
    • B03C3/09—Plant or installations having external electricity supply dry type characterised by presence of stationary flat electrodes arranged with their flat surfaces at right angles to the gas stream
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03C3/00—Separating dispersed particles from gases or vapour, e.g. air, by electrostatic effect
    • B03C3/34—Constructional details or accessories or operation thereof
    • B03C3/40—Electrode constructions
    • B03C3/45—Collecting-electrodes
    • B03C3/47—Collecting-electrodes flat, e.g. plates, discs, gratings
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03C3/00—Separating dispersed particles from gases or vapour, e.g. air, by electrostatic effect
    • B03C3/34—Constructional details or accessories or operation thereof
    • B03C3/66—Applications of electricity supply techniques
    • B03C3/68—Control systems therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03C2201/00—Details of magnetic or electrostatic separation
    • B03C2201/32—Checking the quality of the result or the well-functioning of the device

Definitions

  • the invention relates to a passenger cabin air filter, or more generally to a gas filter and to a housing for the gas filter and to a gas filter system comprising at least the gas filter.
  • Passenger cabin air filters systems remove pollutants from the ambient air and provide the cleaned air to the interior of a passenger cabin of a vehicle. Essentially the same technology may be used in other fields, e.g., for building ventilation.
  • filtration references to removal of particulate matter from a gas stream by a sieving the gas stream using fibrous filter - the sieve.
  • Cleaning the air based on sieving alone requires balancing between the size of the smallest particles to be held back in the sieve and the pressure drop of the sieving element - the fibrous filter medium.
  • Removing particulate matter from a gas stream by filtration appears to be a result of a number of effects including interception, diffusion, inertial impaction. It has been suggested to improve particle removal from a gas stream using electrostatic forces by means of electret filters. The particle removal of these electret filters, however, appears to fade with increasing deposition of the fibers with particles.
  • These active field polarized media gas cleaners usually have a gas filter housing with a receptacle for a gas filter and a high-voltage (HV) source being connected to the electrodes of the gas filter. Once the service life of the gas filter is reached it is removed from the housing and replaced by another one.
  • the housing hence has at least two electrical contacts for removably contacting corresponding electrical contacts of the gas filter, thereby enabling to provide an electrical connection of the gas filter with the HV-source.
  • US 2007/0199450 A1 suggest an air filter having two air permeable ground electrodes and an air-permeable HV electrode in between of these. Between each ground electrode and the HV electrode is a dielectric filter medium. The HV-field between the electrodes polarizes both, the particles as well as the fibers of the dielectric.
  • Air-ionization requires, depending on the distance of the electrode about 5kV and typically -depending on the size of the air-ionizer - a current of a few 10 ⁇ A to 10mA.
  • Corona discharge air cleaners are an example of air-ionizers. Industry scale gas ionizer may have correspondingly larger currents.
  • any change of the filter medium (material, effective surface, thickness, ...), which might be required due to a change of regulatory requirements for gas cleaning and/or due to a user preference for a particular level of cleaning and/or to adapt the gas cleaning system to different geographical or climate conditions is expensive, as it requires as well to replace the HV-source or to initially install an HV-source with an adjustable output voltage.
  • the problem underlying the invention is thus to reduce the costs associated with replacing a gas filter of a first capacity C 1 and electrode surface A 1 with another gas filter of a different capacity C d and/or electrode surface A d , while at the same time being able to verify the presence of the gas filter in a corresponding gas filter housing of a gas cleaning system.
  • a solution of the problem to be solved is the gas filter of claim 1 and the method of claim 12.
  • the dependent claims relate to further improvements of the invention.
  • the gas filter may have an upstream facing side, a downstream facing side and a peripheral narrow facing side connecting the upstream facing side and the downstream facing side.
  • the upstream facing side may usually face toward the gas flow, i.e., the gas flow may enter into the gas filter via its upstream facing side and accordingly leave the gas filter via its downstream facing side.
  • the gas flow may hence flow at least essentially through a cross section being confined by the narrow facing side, but the narrow facing side does not necessarily define the area of the cross section through which the gas flow may pass as will become apparent below.
  • the gas filter comprises as least a filter medium for filtering (i.e., sieving) a gas flow from the upstream facing side through the filter medium to the downstream facing side.
  • the filter medium preferably comprises a capacitor with at least a first electrode and a second electrode.
  • a dielectric medium may be located in between of the first electrode and the second electrode.
  • the first electrode and/or the second electrode and/or the dielectric medium are/is (a) filter media/medium.
  • the at least one filter medium is permeable for a gas (e.g., air), but not for particles above a given particle size.
  • the filter medium can be considered as a sieve.
  • the first electrode is a first electrically conducting filter layer and/or the second electrode is preferably a second conducting filter layer and/or the dielectric medium is an intermediate isolating filter layer, wherein the term filter layer implies that the respective layer is permeable for a gas (like e.g., air) but not for particles above a threshold diameter.
  • the threshold diameters may be different for the different filter layers.
  • the capacitor may be attached to a support.
  • the support is preferably non-conducting.
  • the portion of the surface facing away from the capacitor may be at least a part of the gas filter's narrow facing side.
  • the gas filter may further comprise a first electrical contact (hereinafter ' first contact' ) at a first location.
  • the gas filter may further comprise a second electrical contact (hereinafter 'second contact' ) at a second location.
  • the first and/or second contact(s) are/is attached to the support and/or unitary with the support.
  • the first contact is preferably configured to be removably connected to a high voltage output contact of a high voltage source.
  • the second contact is preferably configured to be removably connected to a ground contact of the high voltage source.
  • the first and second electrical contacts may each be considered as an electrical connector or a terminal.
  • the first and second electrical contacts may each be considered as an electrical connector and/or a terminal.
  • the contacts enable to connect the filter element to a corresponding first and second housing contacts of a gas filter housing.
  • the gas filter housing may comprise the HV-source and/or the first and second housing contacts may be electrically connected to the HV-output terminal and the ground terminal of the HV-source. Only to avoid confusion, the location of the HV-source is irrelevant, i.e., it may be attached to a housing body and hence be comprised by the filter housing or in any other location and not be comprised.
  • the first electrical contact is electrically connected via a first resistance R1 to a branching point and the second electrical contact is electrically connected via a second resistance R2 to the same branching point.
  • the first electrode may be electrically connected to the branching point as well.
  • the second electrode may preferably be electrically connected to the second electrical contact.
  • the corresponding first resistor and the second resistor and the branching point are thus, preferably a part of the gas filter. At least one of these parts may for example be attached to the support or a part of the support.
  • the gas filter enables to adapt the dielectric filter medium and hence the distance between the electrodes or the electrode surface as well as the relative permittivity to any need without changing the HV-source.
  • An installed gas filter can thus be replaced by another gas filter with a different filter medium while avoiding costs or installation errors for replacing or adjusting the HV-source to the new filter medium, because the electrical field E' being intended to be present between the electrodes (after ramp up, i.e.
  • the ability to adjust the voltage across the capacitor in wide range allows to connect the gas filter to the same HV-source terminal, which feeds as well a gas-ionizer.
  • a gas-ionizer may be placed in the gas conduit, preferably upstream of the first electrode, either as a part of the gas filter or as a separate part in the gas conduit.
  • An example gas-ionizer is suggested in the German Patent Application DE 10 2021 120 127.6 , the teaching of which is included herein by reference as if fully disclosed.
  • Typical values for operating gas-ionizers are in the range of a couple of kV (typically 3 to 6kV). At these volage levels, however, the dielectric media of typical active field polarized media gas cleaning filter would be destroyed by sparking.
  • the gas filter as claimed allows to adjust R 2 ′ R 1 ′ + R 2 ′ appropriately, i.e., the voltage across the capacitor U cap t ⁇ R 2 ′ R 1 ′ + R 2 ′ U HV can be adjusted to any reasonable value, for example to a value between 0.5kV and 1.5kV.
  • the maximum current being drawn from the HV-source Max ( I HV ( t )) is lower than the sum of the maximum currents through the gas filter Max ( I gs ( t )) and the gas-ionizer Max ( I ai ( t )), i.e. Max ( I HV ( t )) ⁇ Max ( I gf ( t )) + Max ( I ai ( t )).
  • R 1 + R 2 or R 1 ′ + R 2 ′ , as the case may be
  • Max ( I gf ( t )) can be reduced to practically almost negligible values.
  • a single HV-source can be used to supply both, a gas-ionizer and the gas filter.
  • the gas filter of claim 1 can be used, as the voltage between the first and second electrodes can be adapted as described and because Max ( I HV ( t )) remains almost constant, as Max ( I gf ( t )) ⁇ Max ( I ai ( t )) .
  • the gas filter comprises a third electric contact T3 ((third contact T3) at a third location, wherein the third electrical contact is electrically connected to the first contact via a third resistance R3.
  • This allows to electrically connect the gas-ionizer to the HV-source via the gas filter. If the gas filter has been erroneously omitted, the gas-ionizer is not connected to the HV-source, it remains switched off. Thereby, it can be avoided that the gas-ionizer is operated, if no gas filter is installed, as -in case the gas treated by the gas cleaning system is an oxygen comprising gas, like air- this would lead to an increased Ozon ( O 3 ) concentration in the air leaving the gas filter system. Such increased Ozon ( O 3 ) concentration provides a health risk. As will be explained below, insertion of the gas filter can as well be detected by measuring the voltage and/or the current after switching the HV-source on.
  • the gas filter may comprise a fourth electric contact T4 (fourth contact T4) at a fourth location, wherein the fourth electrical contact is electrically connected to the second contact T2 via a fourth resistance R4.
  • This allows to electrically connect the HV and the ground terminal of the optional gas-ionizer to the HV-source via the gas filter.
  • the advantages are essentially the same as those of the third contact T3. Only to avoid misunderstandings, the term "fourth contact” does not imply that the third contact T3 is present.
  • the gas filter comprises the first, second and fourth contacts T1, T2, T4, but not the third contact T3.
  • the gas filter comprises all four of these contacts T1 to T4, i.e. the first, second, third and fourth contacts T1, T2, T3 and T4.
  • the gas filter may as well comprise the first, second and third contacts T1, T2 and T3, but not the fourth contact.
  • the optional third and/or fourth resistances R3, R4 -if present- may be connected in parallel to the first and second resistances R1, R2, respectively. They may as well be provided by a section of the first and second resistances/resistors R1, R2.
  • the fourth contact point may be in between of the second electrode and the second contact T2. All these options and alternatives may simplify arrangement of the wiring and thus contribute to cutting the cost of the gas filter down.
  • the third resistance R3 between the first electrical contact and the third electrical contact is smaller or equal to the first resistor R1 and/or the second resistor R2, i.e., R 3 ⁇ Max ( ⁇ R 1, R 2 ⁇ ) .
  • the third resistance R3 is significantly smaller than the first resistor R1 and/or the second resistor R2, which can be written as R3 ⁇ ⁇ R ⁇ Max ( ⁇ R 1, R 2 ⁇ ), wherein ⁇ R ⁇ ⁇ 0.5, 0.4, 0.3,0.25,0.2,0.1, 0.05, 0.01, 0.001 ⁇ .
  • At least one of the first, second and/or the third electrical contacts may be attached to and/or located on the support. This eases safely connecting the corresponding contacts with their complementary counterparts of a gas filter housing when inserting the gas filter into the gas filter housing.
  • the first resistor R 1 and/or the second resistor R 2 and/or the third resistor R 3 are/is a conductive polymer and/or a conductive ceramic and/or a conducting compound.
  • the conductive polymer and/or the conductive ceramic and/or a conducting compound are in many legislations not considered as electronic devices. The gas filter therefore is not considered as such and once its service life is reached, the gas filter may be disposed as 'normal waste' instead of being disposed as electronic scrap, being more expensive.
  • the electric contacts as well as the branching point(s) may as well be of said conductive polymer and/or the conductive ceramic and/or conducting compound, thereby reducing the number of materials being required when manufacturing the gas filter -which translates in manufacturing cost reduction- and recycling of the materials being used is as well simplified.
  • the gas filter may comprise a module being formed of the conducting polymer and/or the conducting ceramic and/or a conducting compound, wherein the module comprises or consists of the first contact, the second contact, the branching point, the first resistor R 1 and the second resistor R 2 .
  • the third resistor R 3 and the third contact may as well be a part of the module.
  • module may be manufactured as a single piece (and hence unitary) piece of the conducting polymer and/or conducting ceramic and/or a conducting compound. This allows to cut down manufacturing costs for the gas filter as well as disposal costs.
  • the conductive polymer and/or conducting ceramic and/or a conducting compound may have an outer layer with a specific electrical resistivity ⁇ l and an inner layer or core with a core resistivity ⁇ c .
  • the core may as well be a layer, as long as it is enclosed by the outer layer.
  • the core may have cross section being circular, polyhedric and/or elliptic or have any other cross section being delimited by a single curve. This would correspond to the intuitive notion of the term core and can be considered as a preferred example.
  • the core may have a ring shaped cross section, i.e.
  • the core may be delimited by two closed curves, being closed loops.
  • the core may be located for example in between of two layers, an inner layer and an outer layer.
  • the core may have a specific electrical resistivity ⁇ c wherein ⁇ c ⁇ ⁇ l and/or ⁇ c ⁇ ⁇ ⁇ ⁇ ⁇ l and/or or ⁇ c > ⁇ ⁇ ⁇ ⁇ l , wherein ⁇ ⁇ ⁇ ⁇ 0.9, 0.8, 0.75, 0.6, 0.5, 0.4, 0.3,0.25,0.2,0.1 ⁇ .
  • the conducting polymer or the conducting ceramic comprises conductive fibers being embedded in a non-conducting polymer and/or conducting ceramic and/or a conducting compound
  • the fibers in the core may be essentially randomly oriented and not even straight.
  • the conducting fibers may, e.g., due to the process of extruding and/or injecting the polymer and/or the slip (a ceramic precursor) align. This may lead to an inhomogeneous transition resistance along the surface of the polymer and/or ceramic.
  • the core extends through the outer layer at the first location and /or the second location and/or the third location.
  • the core having a more homogenous and hence defined transition resistance can be contacted.
  • the core is preferably not covered by the outer layer. This can be obtained, e.g. by locating a sprue at the respective location, thereby after removing the sprue, the core becomes exposed.
  • any subtractive method like for example grinding, polishing, drilling, milling, etching, ...) to remove a portion of the outer layer and thereby expose the core.
  • the conducting polymer and/or conducting ceramic may have at least one recess at the first location and/or the second location and/or the third location.
  • the recess allows a corresponding protrusion of the gas filter housing to enter into the recess.
  • a conducting blade being that is optionally attached to the protrusion may thereby cut into the core and provide for reliable electrical connection of the first, second and/or third electrical contact, respectively with the core.
  • the risk of injuries when inserting the blade can be reduced, as the protrusion may extend over the blade and thereby prevent human fingers or other parts from being injured by the blade or a potentially (and unitedly) applied HV to the blade.
  • the gas filter housing may hence comprise at least one (preferably conducting) blade positioned to penetrate into the conducting polymer and/or the conducting ceramic and/or the conducting compound at the first location and/or the second location of the gas filter.
  • This blade may be, or be a portion of the first and/or second and/or third housing contact.
  • the blade is located in front of the respective housing contact, and hence configured to cut through the conducting polymer and/or conducting ceramic and/or conducting compound while the associated housing contact may follow the blade in the slot being provided by the cutting edge and thereby may be configured to contact the optional core of the conducting polymer and/or conducting ceramic and/or conducting compound.
  • the already mentioned protrusion of the gas filter housing may hence extend into the gas filter receptacle being provided by the gas filter housing.
  • the protrusion may extend from a housing wall towards the inside of the housing, i.e., towards the space being configured to receive the gas filter.
  • the protrusion may be located to located to extend into the recess of a
  • the protrusion may be or comprise a ring and/or ring segment. The ring and/or ring segment may be located to at least partially encircle an outer boundary of the first and/or second and/or third electrical contact of the gas filter.
  • the blade may be located inside of the ring /ring segment.
  • the protrusion may extend further into the gas filter receptable than the blade.
  • the protrusion may hence protect the blade from unintended touching or contacting.
  • the corresponding housing contact is thus protected by the protrusion, while at the same time the protrusion protects a worker during replacement of the gas filter from being hurt by the blade or a potentially applied voltage to said blade.
  • at least the distal portion of the protrusion is non-conducting, i.e. electrically isolating.
  • the protrusion supports at least a portion of the blade.
  • the blade can be made particularly thin.
  • the forces required to install the gas filter or more precisely required to drive the blade into the conducting polymer and/or the conducting ceramic and/or the conducting compound are low.
  • the gas filter may further comprise a gasket for sealing a gap to a wall defining gas filter receptacle of the gas filter housing.
  • a gasket for sealing a gap to a wall defining gas filter receptacle of the gas filter housing.
  • at least a portion of the conductive polymer and or the conductive ceramic may be positioned in between of the support and the gasket.
  • the gasket hence protects the polymer against mechanical stress and at the same time isolates the portion of the conductive polymer and/or conductive ceramic.
  • the gasket may as well attach the polymer to the support by adhesive bonding.
  • At least a portion of the gasket may be made of the conductive polymer.
  • the number of different parts of the gas filter can be further reduced, which contributes to a reduction of the manufacturing cost.
  • the conductive polymer and/or conductive ceramic and/or a section thereof may be attached to and/or may extend over a section of the first electrode and/or of the second electrode, wherein an isolating sheath is located in between of at least the section of the conductive polymer and/or conductive ceramic.
  • the gas filter enables to automatically detect the presence in a gas filter system as described herein without requiring additional contacts by the method of claim 12. Based on the result of the determination an optionally present gas-ionizer of the corresponding gas cleaning system may be controlled. If correctly installed, the gas filter's first and second electrical contacts are electrically contacting corresponding first and second housing contacts T11, T12. These housing contacts are preferably connected to an HV-source.
  • the method may comprise the step of providing at least a first voltage U d to the housing contacts T11, T12 and to determine the current I h ( U d ) through the housing contacts T11, T12.
  • This current allows to determine, whether the gas filter is present or not by comparing the current I h ( U d ) through the housing contacts T11, T12 with a threshold current I t and if I t > I h ( U d ) is true, there is no second resistor R 2 through which a current I h ( U d ) may flow.
  • the gas-ionizer is preferably switched off and/or maintained switched off.
  • This may be done by simply switching the HV-source off and/or by controlling the HV-source to provide a voltage below the onset voltage U o of gas ionization by said gas-ionizer. Further an error message may be symbolized, for example displayed in a screen or by simply illumination a control light.
  • the gas-ionizer may be controlled to operate, as it may be expected that the gas filter is installed.
  • the voltage provided to the gas-ionizer may be above its onset voltage U o as in this case it is very unlikely that the gas filter has not been installed.
  • any other value ⁇ may represent or be a measure of the current I h ( U ) or at least of I h ( U d ). Such value ⁇ may be measured and/or calculated.
  • Determining any of these values ⁇ shall be considered in the context of this patent as determining the current I h as these values ⁇ provide information about the current I h .
  • Examples for such values ⁇ are for example the power consumption of the HV-source (obtainable by an input power measurement), the current drawn by the HV-source (obtainable by an input current measurement), a duty cycle of a pulse width modulated signal controlling the voltage across the housing terminals T11, T12 to U d , a magnetic field, the resistance between the housing terminals T11, T12 or the like.
  • the first voltage U d obeys
  • This choice of the voltage U d reduces the risk of erroneously controlling the gas-ionizer to operate or not, because the difference between the currents in the situations in which no gas filter is installed and when the gas filter is installed maximizes.
  • This measure is particularly effective is the gas-ionizer is connected in parallel to first and second contacts of the gas filter.
  • gas stream and gas flow are used interchangeably herein. Further, in this disclosure, the term gas includes as a preferred example the term gas.
  • An isolator has an (almost) infinite resistivity, in other words, there is a band gap between the conduction band and the fermi level.
  • a conductor in contrast fails to show this band gap, as the fermi level is in the conduction band.
  • the terms isolator, isolating, conductor, conducting etc. reference to electrical conductivity and not to thermal properties.
  • conductive polymer and/or conductive ceramics encompasses not only polymers and/or ceramics being conductors or semiconductors, but as well compound materials based on a matrix of non-conducting polymers and/or non-conducting ceramic materials into which a conductive material like e.g., metal and/or carbon fibers and/or graphite or the like have been integrated.
  • the conducting compound hence may have a non-conductive matrix into which conductive fibers have been embedded and the conductivity of the compound can hence be attributed to the conductive fibers (which may as well be filaments, particles, beads or the like), being for example randomly distributed in the matrix.
  • first, second, third, n th electrical contacts are herein considered as releasably contactable contacts which may as well be referred to as electrical terminal or electrical connector. These electrical contacts may be formed for example by a male pin type connector and/or a corresponding female sleeve type connector and/or a simple contact pad.
  • FIG. 1 shows an example gas filter 1.
  • the gas filter has an upstream facing side 3 and a downstream facing side 4, assuming a gas flow direction as indicated by arrow 2. Of course, the gas flow direction could be inverted as well.
  • a narrow facing side 5 connects the upstream facing side 3 and the downstream facing side 4.
  • the gas filter 1 has a filter medium 20.
  • the filter medium 20 may comprise one or more plied sheets, but this is only a preferred example. Other types and shapes of filter media may be used as well.
  • the filter medium 20 may preferably comprise at least three layers: two electrode layers 21, 22 and a dielectric layer 23 in between of the electrode layers 21, 22. Each of the electrode layers 21 may thus be considered as an electrode 21, 22 of a capacitor, wherein the dielectric layer 23 is the capacitor's dielectric 23 in between of the two electrodes 21, 22 (cf. Fig. 6 ).
  • the filter medium 20 may thus comprise and/or form a capacitor.
  • the gas filter 1 may further comprise at least one support 10.
  • the support 10 comprises a front wall 11 and rear wall 12 being preferably sealingly attached to opposing portions of the narrow side of the filter medium 20.
  • Side walls (not shown) may be comprised as well by the gas filter 1, but as shown they may be omitted.
  • the gas filter 1 may have an electric module 30.
  • the electric module 30 may comprise or preferably consist of an electrically conducting polymer string 30, which may as well be referred to as duct 30, string 30 or electrical conduit 30.
  • the module may comprise or consist of an electrically conducting ceramic string and/or a conducting compound. Only for linguistic simplicity, we use the term conductive polymer herein as a pars pro toto for conductive polymer and / or conductive ceramic and / or conductive compound.
  • the electrically conducting string may have a first electrical contact T1.
  • the first electrical contact T1 may preferably have a ring structure and hence forms a first recess being at least partially enclosed by the polymer string.
  • the ring structure is not necessarily closed and may hence form a ring segment or a ring.
  • the first electrical contact may be connected by the conductive polymer 30 with a branching point B and thus the portion of the conductive polymer 30 which forms the electrical connection between the first contact T1 and the branching point B forms a first resistor R 1 .
  • the electrically conducting polymer string may have a second electrical contact T2, which as well may as well form a ring or a ring segment.
  • the second contact T2 is preferably connected by a portion R 2 of the conducting polymer string 30 with the branching point.
  • the portion of the conducting polymer connecting the second contact T2 and the branching point may define a second resistor R 2 .
  • branching point B and the second terminal may preferably be connected, e.g., by said conducting polymer 30 to one of the first and the second electrode 21, 22.
  • Inserting the gas filter into a gas filter housing as shown, e.g., in Fig. 5 hence enables to provide an electrical connection of the first and second electrical contacts (T1, T2) with two poles of a HV-source, which may provide a voltage U HV .
  • the voltage U cap can be adjusted to match the requirements provided by capacitor.
  • Fig. 2 and 3 each show a slightly different gas filter 1.
  • the description of Fig. 1 may be read as well on Fig. 2 and 3 .
  • the gas filters of Fig. 2 and 4 each have a gasket 40.
  • the gasket 40 may extend over the edge being formed by the upstream facing side 3 and the narrow facing side 5 and it may cover a portion of the string 30 thereby serving as adhesive for attaching the conductive polymer 30.
  • the gasket 40 covers the portion of the conducting polymer 30 that contacts the second electrode.
  • the gasket covers and hence fixates a portion of the electrical conduit 30, i.e. a portion of the string 30, that extends along a downstream edge of the support 10
  • Fig. 4 shows an example gas filter housing 100.
  • the gas filter housing 100 may be attached to or be integrated in a gas conduit and in this sense, its side walls 111 to 114 may be considered as a part of the gas conduit.
  • the front sidewall 111 may have an opening enabling to insert the rear portion of gas the filter 1 of Fig. 1 or Fig. 2 into the gas filter housing 100 as sketched in Fig. 5 .
  • the gas filter housing may preferably comprise at least a first and a second housing contact T11 and T12, configured to contact the first and the second contacts T1, T2 of the gas filter 1.
  • the at least one of the housing contacts T11, T12 comprises blade configured to penetrate through at least a portion of the polymer string 30, to thereby contact an inner portion of the polymer string, which inner portion may be referred to as a core.
  • Fig. 5 shows the example gas filter 1 of Fig. 3 partially inserted into the gas filter housing 100.
  • the side wall 114 has been omitted and the gasket 40 has been shown transparent.
  • the first contact T1 is configured to contact the first housing contact T11 and the second contact T2 is configured to contact the first housing contact T12.
  • Fig. 6 shows a detail of a filter medium 20 as may be used in any of the examples in Fig. 1 to 3 and 4 .
  • the filter medium has a first electrode 21, a second electrode and a dielectric medium 23 between the first and the second electrodes 21, 22.
  • T1 and T2 symbolize the first and second electrical contacts
  • B a branching point
  • the resistors R 1 and R 2 represent the electrical resistance of the corresponding connections by, for example the polymer string 30 as described above.
  • Fig. 7 shows a diagram of three different current I ( U ) curves, wherein I ( U ) is indicated in mA and the voltage U is indicated in kV.
  • the coarsely hatched curve describes the current across the electrical contacts T1 and T2 in the example of Fig. 6 .
  • the current values have been measured after the current stabilized, i.e., the current being depicted is essentially the current through the resistor R2 being defined by Ohm's law. Below 3.5kV, the coarsely hatched curved is identical with the continuously drawn curve and hence cannot be optically distinguished.
  • the finer hatched curve describes the current through a gas-ionizer that is connected to the same HV-source, in parallel the electrical contacts T1 and T2.
  • the gas ionization starts at an corona inception voltage of in this example about 3.5kV (i.e. 3.5 kV is an example corona inception voltage U o , that can be varied, e.g., by increasing or decreasing the distance of the gas-ionizer electrodes) and the current increases with increasing slope.
  • the corona inception Voltage depends on the gas-ionizer and the gas but can be determined easily by measuring the current I ( U ) as a function of the supply voltage.
  • the solid line is the total current flowing if the gas-ionizer is connected in parallel to the HV-source supplying the T1 and T2 the electrical conduit 30 and hence the filter medium 20 (see Fig. 6 ).
  • the gas filter 1 has been inserted into the gas filter housing or not:
  • the HV-source is preferably switched off.
  • operation of the gas-ionizer does not take place and the ozone concentration in the air being provided by the corresponding gas cleaning system is low. Health risks due to an unintendedly high ozone-concentration can be avoided.
  • the given voltage U d is below the corona inception voltage U o or in the vicinity ( ⁇ 2 kV , preferably ⁇ 1 kV , ⁇ 0.75 KV or ⁇ 0.5 KV ) of the corona inception voltage U o of gas ionization by the installed gas-ionizer.
  • this voltage range the difference between the currents of the coarsely hatched curve and the finer hatched curve has a maximum.
  • the risks of erroneously switching the HV-source off and of erroneously operating the air ionizer is reduced.
  • Fig. 8 shows a detail a further gas filter housing 100.
  • the gas filter housing 100 has a housing wall 113 with a block 120 for defining the position of the gas filter 1.
  • the gas filter 1 may be inserted from the top, and may reside on the block 120.
  • the gas filter housing 100 may have at least one (first) protrusion 131, the protrusion may be located to engage into a corresponding recess of an electrical contact T1, T2, or T3 of a conducting polymer, and/or a conducting ceramic and/or a conducting compound as shown in Fig. 1, 2 , 3 , and 5 .
  • the protrusion 131 may supports a blade T11 with a cutting edge.
  • the cutting edge points opposite to the direction of insertion of a gas filter, e.g. towards the housing opening in the front wall 111 as shown in Fig. 4 .
  • the cutting edge of the blade shaped first housing contact T11 may penetrate into the material of duct 30 (i.e. into conducting polymer, and/or a conducting ceramic and/or a conducting compound) of the gas filter 1 and thereby electrically contact the core of said duct 30 with an HV-terminal of a HV-source 141.
  • a blade T13 may be attached to the third protrusion.
  • the blade may form a third housing contact T13 and may be connected with an HV-terminal of a gas ionizer 143.
  • the gas ionizer is connected to the HV-source 141 only if the duct 30 electrically connects the first and the third housing terminals 141, 143.
  • the gap in between of the first and the third housing contacts T11, T13 is exaggeratedly small, thereby the resistance between the first and the third housing electrode is small as well.
  • the distance should be selected reasonably large to avoid ionizing ambient air in the gap in case no gas filter has been inserted.
  • a fourth isolating protrusion may be located in between of the housing contacts T12 and T13 to thereby allow these to be placed closer together, which results in a smaller resistance R3 between first and the third contact if the gas filter is installed.
  • the gas filter housing may have a second housing contact T12 being formed by a second blade T12 and being optionally attached to a second protrusion. These details are not depicted, as they may look like their first or third protrusion and/or blade respectively.

Landscapes

  • Engineering & Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Filtering Materials (AREA)
EP22157505.3A 2022-02-18 2022-02-18 Filtre d'air de cabine avec polarisation Pending EP4230299A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP22157505.3A EP4230299A1 (fr) 2022-02-18 2022-02-18 Filtre d'air de cabine avec polarisation
EP22182008.7A EP4230298A1 (fr) 2022-02-18 2022-06-29 Filtre d'air de cabine avec polarisation
PCT/EP2023/053663 WO2023156403A1 (fr) 2022-02-18 2023-02-14 Filtre à air de cabine à polarisation
PCT/EP2023/053664 WO2023156404A1 (fr) 2022-02-18 2023-02-14 Dispositif de filtre à air de cabine et composants

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP22157505.3A EP4230299A1 (fr) 2022-02-18 2022-02-18 Filtre d'air de cabine avec polarisation

Publications (1)

Publication Number Publication Date
EP4230299A1 true EP4230299A1 (fr) 2023-08-23

Family

ID=80685222

Family Applications (1)

Application Number Title Priority Date Filing Date
EP22157505.3A Pending EP4230299A1 (fr) 2022-02-18 2022-02-18 Filtre d'air de cabine avec polarisation

Country Status (1)

Country Link
EP (1) EP4230299A1 (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0691199A (ja) * 1992-07-01 1994-04-05 Yaskawa Electric Corp 空気清浄機のフィルターセットの取付状態検出装置
US20060137527A1 (en) * 2004-12-27 2006-06-29 Joannou Constantinos J Electronic air filter with resistive screen and electronic modular assembly
JP2006234246A (ja) * 2005-02-23 2006-09-07 Sharp Corp 空気調和機
US20070199450A1 (en) 2005-12-29 2007-08-30 Wiser Forwood C Filter media for active field polarized media air cleaner
US20080190772A1 (en) * 2007-02-09 2008-08-14 Lennox Manufacturing, Inc., A Corporation Of Delaware Apparatus and method for removing particles from air

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0691199A (ja) * 1992-07-01 1994-04-05 Yaskawa Electric Corp 空気清浄機のフィルターセットの取付状態検出装置
US20060137527A1 (en) * 2004-12-27 2006-06-29 Joannou Constantinos J Electronic air filter with resistive screen and electronic modular assembly
JP2006234246A (ja) * 2005-02-23 2006-09-07 Sharp Corp 空気調和機
US20070199450A1 (en) 2005-12-29 2007-08-30 Wiser Forwood C Filter media for active field polarized media air cleaner
US20080190772A1 (en) * 2007-02-09 2008-08-14 Lennox Manufacturing, Inc., A Corporation Of Delaware Apparatus and method for removing particles from air

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
FRANK JORDAN: "PhD-Thesis", 2001, UNIVERSITY DUISBURG, article "Untersuchungen zum Partikelab-scheideverhalten submikroner Partikel in Faserfiltern im elektrischen Feld"

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