WO1995017239A1 - Appareil permettant d'enlever des particules d'un fluide - Google Patents

Appareil permettant d'enlever des particules d'un fluide Download PDF

Info

Publication number
WO1995017239A1
WO1995017239A1 PCT/IB1994/000436 IB9400436W WO9517239A1 WO 1995017239 A1 WO1995017239 A1 WO 1995017239A1 IB 9400436 W IB9400436 W IB 9400436W WO 9517239 A1 WO9517239 A1 WO 9517239A1
Authority
WO
WIPO (PCT)
Prior art keywords
particles
fluid
polarity
chamber
causing
Prior art date
Application number
PCT/IB1994/000436
Other languages
English (en)
Inventor
Dennis Ryder
Original Assignee
Philips Electronics N.V.
Philips Norden Ab
Philips Electronics Uk Limited
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 Philips Electronics N.V., Philips Norden Ab, Philips Electronics Uk Limited filed Critical Philips Electronics N.V.
Publication of WO1995017239A1 publication Critical patent/WO1995017239A1/fr

Links

Classifications

    • 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
    • B03C3/10—Plant or installations having external electricity supply dry type characterised by presence of electrodes moving during separating action
    • 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
    • B03C3/017—Combinations of electrostatic separation with other processes, not otherwise provided for
    • B03C3/0175—Amassing particles by electric fields, e.g. agglomeration
    • 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

Definitions

  • This invention relates to apparatus for removing particles such as dust or smoke particles from a fluid such as air.
  • EP-A-532105 describes apparatus for removing particles such as dust particles from fluid such as air.
  • air flows through a hollow filter body and the filter body is rotated so that the centrifugal force exerted on the particles causes them to move transversely of the axis of rotation so as to be deposited on the material of the filter body.
  • the force exerted upon the dust or similar particles will of course depend on the speed of rotation of the filter body and upon the size and weight of the particles so that the smaller the particles the greater the rotation speed required to enable efficient collection of the particles.
  • filter Other forms of filter are of course known.
  • a common form of filter simply uses a porous sheet of material or number of layers of material which material allows air to pass through but prevents the passage of particles larger than a given size.
  • the size of the particles which can be filtered or removed from the air depends of course on the structure of the filter material so that the finer the filter material the smaller the particles which can be efficiently removed by the filter.
  • apparatus for removing particles from a fluid which apparatus comprises means for causing fluid to flow from an inlet to an outlet of the apparatus, a charging chamber communicating with the inlet, means for causing some particles in fluid flowing through the chamber to attain an electrical charge of one polarity and for causing other particles in fluid flowing through the chamber to attain an electrical charge of a polarity opposite to the one polarity, a mixing chamber communicating with the charging chamber for allowing oppositely charged particles in fluid flowing from the charging chamber to mix to form larger particles and filtering means positioned between the mixing chamber and the outlet of the apparatus for removing particles from fluid flowing through the mixing chamber before the fluid reaches the outlet.
  • apparatus in accordance with the invention causes particles within fluid passing through the apparatus to be combined or agglomerated with other particles to form larger particles which can be more easily filtered so allowing the apparatus to filter out efficiently smaller particles than could be filtered out by the filtering means alone or, as an alternative, allowing the same size particles to be filtered out but using a larger pore, and so cheaper, filter material or, where a rotatable filter body is used, using a lower rotation speed which should enable either the use of a cheaper motor for rotating the filter body or allow the motor to operate at a lower speed and so more quietly.
  • the means for causing particles to attain an electrical charge of one polarity or of the opposite polarity may comprise first and second electrically conductive members positioned within the chamber and means for applying high voltages of opposite polarities to the first and second electrically conductive members.
  • first and second electrically conductive members positioned within the chamber and means for applying a high voltages of opposite polarities to the first and second electrically conductive members should be more easily controllable.
  • the charging chamber may comprise at least one first passageway and at least one second passageway for the flow of fluid and the means for causing particles to attain an electrical charge of one polarity or of the opposite polarity may comprise means for causing particles in fluid flowing through the at least one first passageway to attain an electrical charge of one polarity and means for causing particles in fluid flowing through the at least one second passageway to attain an electrical charge of a polarity opposite to the one polarity.
  • This separation of the fluid enables the charging of particles and the mixing of charged particles to be well-controlled.
  • the means for causing particles to attain an electrical charge of one polarity or of the opposite polarity may comprise at least one first electrically conductive member positioned in the at least one first passageway and at least one second electrically conductive member positioned in the at least one second passageway and means for applying high voltages of opposite polarities to the first and second electrically conductive members.
  • a number of first passageways and a corresponding number of second passageways may be provided, so allowing for a greater air flow through the apparatus.
  • the passageways may be arranged so that each first passageway is adjacent one or more second passageways so that particles charged with one polarity exit the charging chamber close to particles charged with the opposite polarity to facilitate mixing and agglomeration of oppositely charged particles to form larger particles.
  • the passageways may be of any suitable cross-section, for example rectangular, circular or hexagonal, and may be arranged in any suitable packing arrangement.
  • the filtering means may comprise a filter material for extracting particles from the fluid flow.
  • the filtering means may comprise a hollow filter body having a central axis oriented generally in the direction of fluid flow and means may be provided for causing the cylindrical body to rotate about its central axis.
  • the filter body may be formed of a layer of material wound into a substantially cylindrical shape about the central axis, the layer being of uneven thickness so as to form channels between adjacent windings of the material. In such circumstances, the rotation of the filtering means should be sufficient to cause fluid flow through the apparatus and a separate means for causing fluid flow through the apparatus should not be necessary.
  • the filtering means may comprise a further chamber or so-called cyclone in the form of a hollow body having an inner surface which is rotationally symmetric about an axis extending through the body and fluid from the mixing chamber may be directed into the cyclone so as to be tangentially incident on the inner surface to cause particles in the fluid to impact the inner surface and either stick to the inner surface or drop out of the fluid to an appropriate collection area.
  • US-A-4162144 describes a method and apparatus for treating electrostatically charged airborne particles to reduce deposition on walls and other exposed surfaces when the air is filtered using electrostatic precipitator which consist of, for example, charged plates interleaved with grounded plates onto which particles charged by the charged plates deposit.
  • electrostatic precipitator consist of, for example, charged plates interleaved with grounded plates onto which particles charged by the charged plates deposit.
  • the electrostatic precipitator cause airborne particles to be charged and precipitated out of the airstream.
  • some of the charged particles may exit the apparatus with the filtered air and may be deposited on surrounding walls, resulting in the accumulation of dirt.
  • US-A-4162144 proposes that two electrostatic precipitators be used which charge particles with opposite polarities so that, if any charged particles are not precipitated out but exit the precipitator with the cleaned air, the oppositely charged particles mix so neutralising the charge and thus reducing the likelihood of particles being deposited on surrounding surfaces.
  • Figure 1 illustrates, by way of a schematic part cross-sectional view, one example of apparatus in accordance with the invention
  • Figure 2 shows a perspective view of one example of a filtering means for use in the apparatus shown in Figure 1 ;
  • Figure 3 shows a schematic part-sectional view of another example of a charging chamber for use in the apparatus shown in Figure 1 ;
  • Figure 4 illustrates, by way of a schematic part cross-sectional view similar to Figure 1, another example of apparatus in accordance with the invention;
  • Figure 5 illustrates schematically test apparatus for demonstrating the operation of the charging chamber
  • Figure 6 illustrates graphically the relationship between the size and mass of particles emitted from the apparatus shown in Figure 5 when no voltages are applied to the electrically conductive members;
  • Figure 7 illustrates graphically the relationship between the size and mass of particles emitted from the apparatus shown in Figure 5 when voltages are applied to the electrically conductive members to cause particles in the respective first and second passageways to become oppositely charged.
  • Figure 8a is a schematic side view and Figure 8b is a schematic top plan view of one other possible form of filtering means for use in the apparatus shown in Figure 1 ;
  • apparatus 1 for removing particles 2 from a fluid 3 which apparatus 1 comprises means 15 for causing fluid to flow from an inlet 6 to an outlet 11 of the apparatus, a charging chamber 24 communicating with the inlet 6, means for causing some particles in fluid flowing through the charging chamber 24 to attain an electrical charge of one polarity and for causing other particles in fluid flowing through the charging chamber 24 to attain an electrical charge of a polarity opposite to the one polarity, a mixing chamber 9 communicating with the charging chamber 24 for allowing oppositely charged particles in fluid flowing from the charging chamber 24 to mix to form larger particles and filtering means 10 positioned between the mixing chamber 9 and the outlet 11 of the apparatus 1 for removing particles from fluid flowing through the mixing chamber 9 before the fluid reaches the outlet 11.
  • such apparatus causes particles within fluid passing through the apparatus 1 to be combined or agglomerated with other particles to form larger particles which can be more easily filtered so allowing the apparatus to filter out efficiently smaller particles than could be filtered out by the filtering means 10 alone or, as an alternative, allowing the same size particles to be filtered out but using a lower grade or coarser, and so cheaper, filter material or, where a rotatable filter body is used, using a lower rotation speed which should enable either the use of a cheaper motor for rotating the filter body or allow the motor to operate at a lower speed and so more quietly.
  • the apparatus 1 shown has a housing 12 within which a motor 13 is mounted by means of resilient suspension couplings 14.
  • a centrifuge arrangement 15 is fixedly mounted in conventional manner onto the output shaft 16 of the motor 13.
  • the centrifuge 15 houses the filtering means 10 which is in the form of a hollow cylindrical body wound from a layer of filter material 10b as will be described in greater detail below with reference to Figure 2.
  • fluid generally air
  • fluid flows from the inlet 6 through a central portion 23 of the housing and is deflected by deflection blades 17a in a deflection chamber 17 back up through the filtering means 10.
  • Further deflection blades 18 are coupled to a conventional bushing arrangement 19 by ribs 20.
  • the bushing arrangement 19 is held securely in place on the output shaft 16 by means of a bolt 21.
  • the centrifuge 15 In operation of this apparatus, activation of the motor 13 causes the centrifuge 15 to rotate, so causing fluid, generally air, to be drawn in through the inlet 6. Air drawn through the inlet 6 is drawn through the filtering means 10 and filtered air passes out through the outlet 11. The centrifugal force exerted on particles within the air stream by virtue of the rotation of the centrifuge 15 causes the particles to move transversely of the axis of rotation of the motor output shaft 16 and to adhere to the filter material 10b.
  • the filtering means 10 is in the form of a hollow filter body and, in this example, is formed by winding a sheet of filter material 10b upon itself to define channels 10a extending substantially parallel to the axis of the filter body 10.
  • FIG 2 shows one particular example of a possible configuration for the filtering means 10.
  • the filter material 10b comprises a corrugated cardboard and the channels 10a are defined by spaces formed between the corrugations and the adjacent portion of the layer of filter material 10b.
  • any suitable material which has an uneven thickness and so can define such longitudinally extending channels 10a may be used to form the filter body 10.
  • Alternative forms of filter bodies 10 and further details of the apparatus 1 as so far described are given in our co- pending European Patent Application Publication Number EP-A-532105.
  • the charging chamber 24 may have any suitable configuration.
  • the charging chamber 24 comprises first and second passageways 4 and 5 and the means for causing some particles in fluid flowing through the chamber 24 to attain an electrical charge of one polarity and for causing other particles in fluid flowing through the chamber 24 to attain an electrical charge of a polarity opposite to the one polarity comprises respective first and second electrically conductive members 28 and 29 positioned in the first and second passageways 4 and 5 and means 26, 27 for applying high voltages of opposite polarities to the first and second electrically conductive members 28 and 29.
  • the charging chamber 24 may have any suitable configuration for defining separate isolated first and second passageways 4 and 5. There may be any desired number of first passageways 4 and a corresponding number of second passageways 5. Thus, although only a single first passageway 4 and a single second passageway 5 are shown in Figure 1 , the charging chamber 24 may have, as illustrated in the example shown in Figure 3, a number of first and second passageways 4 and 5 which should enable a greater flow rate through the apparatus.
  • the charging chamber 24 comprises a frame 25 having dividing walls 25a which define the first and second passageways 4 and 5. As shown, the dividing walls 25a define only one first and one second passageway in Figure 1 and define an equal number (four of each as shown) of first and second passageways 4 and 5 in the example shown in Figure 3.
  • a respective electrically conductive member 28 extends longitudinally through each first passageway 4 and is coupled to a negative high voltage (HT) source 26.
  • HT positive high voltage
  • each first passageway 4 has a corresponding adjacent second passageway 5. It will of course be appreciated, that any appropriate arrangement and pattern of passageways 4 and 5 may be adopted. The alternate positioning of first and second passageways 4 and 5 may have advantages in that oppositely charged particles should then exit from adjacent passageways, so facilitating agglomeration.
  • the first and second passageways 4 and 5 may have any desired cross-sectional shape, for example rectangular, circular or hexagonal, and may be arranged in any suitable packing arrangement, for example a hexagonal close packing arrangement.
  • first and second passageways 4 and 5 may be used. It may be possible to use other methods of charging the particles, such as electrostatic charging by causing the fluid to flow over a charged plate or the like so as to attain charge in a manner similar to that in which a Van de Graaff generator or Wimshurst machine operates.
  • electrostatic charging by causing the fluid to flow over a charged plate or the like so as to attain charge in a manner similar to that in which a Van de Graaff generator or Wimshurst machine operates.
  • first and second electrically conductive members 28 and 29 positioned within the chamber and means 26 and 27 for applying a high voltages of opposite polarities to the first and second electrically conductive members 28 and 29 should be more easily controllable.
  • Figure 4 is a cross-sectional view similar to Figure 1 of another example of apparatus 1 ' in accordance with the invention in which the inlet and outlet 6 and 11 are provided at opposite ends of the filtering means 10 so that air flows without deflection directly to the filtering means 10 housed in the centrifuge 15 and from the filtering means to the outlet 11.
  • Such an arrangement may enable the use of a radially larger filtering means 10.
  • the outlet 6 is provided at the bottom of the apparatus 1 ' and is covered by a grille 6a to prevent extremely large particles, insects or fingers from entering the apparatus 1 ' while the outlet 11 is provided in an upper part of the housing 12.
  • the apparatus 1 ' may be rotationally symmetric about the axis of rotation of the centrifuge 15, although the inlet 6 and outlet 11 may not extend completely around the housing 12.
  • the motor 13 is mounted to the housing 12 by means of a suitable 5 journalled bearing 13a which is illustrated only schematically in Figure 4.
  • the charging chamber 24 is positioned at any suitable location between the inlet 6 and the filtering means 10, for example the location shown in Figure 4.
  • Flow guiding blades 30 or similar flow directing means may be provided to direct incoming air from the inlet 6 to the filtering means 10.
  • the motor 13 may be provided within a housing 31 ⁇ o to assist the desired air flow, if considered necessary.
  • the centrifuge 15' has a central shaft 15a mounted to the motor output shaft 16.
  • a lower impeller 15b of the centrifuge 15' is secured to the central shaft 15a by means of a bolt 21 a or similar arrangement so that the lower impeller rotates with the central
  • the lower impeller 15b has twenty four vanes 15c.
  • the filtering means 10 is mounted to the lower impeller 15b and an upper impeller 15d (which may have a similar number of blades 15e) is mounted over the filtering means 10 onto the other end of the central shaft 15a by means of a further bolt 21b or similar arrangement to guide air exiting the filtering means 10 towards the outlet 11.
  • a lid 12a of the housing 12 may be secured by an appropriate conventional bearing (illustrtaed only very schematically) to the bolt 21 b so as to allow the central shaft 15a to rotate while the lid remains stationary.
  • fluid generally air flows from the inlet 6 directly to the filtering means 25 10 housed in the centrifuge through the charging chamber 24 and then from the filtering means to the outlet 11.
  • the charging chamber 24 may have any suitable construction and may be similar to that shown in Figure 3, although, as indicated schematically in Figure 4, depending upon where the charging chamber 24 is located along the path between the inlet 6 and the filtering means 10, the charging chamber 30 24 may need to adopt an annular shape.
  • the rate of flow of fluid through the passageways 4 and 5, the cross-sections and lengths of the passageways 4 and 5 and the material forming the walls 25a of the passageways 4 and 5 are selected so that the fluid flow is preferably substantially laminar, that is non-turbulent, and the amount of any deposition of charged particles on the walls 25a of the passageways is kept as small as possible.
  • the walls 25a of the first and second passageways 4 and 5 may be formed of or coated by a material which slowly leaks electrical charge or which discharges, in a manner similar to voltage surge arrestors, when a predetermined quantity of charge has built up on the walls.
  • the passageways 4 and 5 may be provided with a suitable removable and replaceable lining (not shown) to enable any particles which may inadvertently accumulate within the passageways 4 and 5 to be removed with the lining.
  • a space between the charging chamber 24 and the filtering means 10 forms the mixing chamber 9 in which the positively and negatively charged particles are allowed to mix.
  • the centrifuge 15 is positioned so as to assist in the mixing or circulation of the fluid exiting from the first and second passageways 4 and 5 without causing any significant disassociation of agglomerated particles.
  • the mixing chamber 9 may be shaped or contain means such as deflection plates or rotatable mixing members to assist in the mixing of the fluid flows from the first and second passageways 4 and 5.
  • Oppositely charged particles attract one another and stick together forming larger agglomerated particles which then travel in the air stream towards and then through the filtering means 10.
  • the fact that the dust or smoke etc particles entering the filtering means 10 are larger than the particles which entered the inlet 6 of the apparatus 1 means that the effect of the centrifugal force exerted by the operation of the centrifuge 15 on the particles is greater than it would otherwise have been and accordingly the dust or dirt particles are more likely to be propelled radially of the centrifuge and so to adhere to the walls of the filtering means 10.
  • This advantage may be used to reduce the minimum size of particles which can be extracted by the apparatus from the incoming air, or alternatively, if the apparatus 1 without the charging chamber 24 was capable of extracting particles of a desired minimum size, may allow the use of a lower rotation speed for the motor 13.
  • the use of a lower rotation speed has the advantage of either allowing for a less expensive motor to be used or, possibly preferably, allowing for quieter operation of the apparatus 1.
  • the inlet 6 should, as shown schematically in Figures 1 and 4, have a suitable grid or grill to prevent the ingress of very large particles and insects such as spiders and, more importantly, to prevent a person, particularly a child, poking their fingers into the apparatus 1.
  • Figure 5 illustrates test apparatus 30 which has been used to demonstrate the effectiveness of a charging chamber such as the charging chamber 24 shown in Figure 1 or Figure 4.
  • the first and second passageways 4 and 5 are defined by two parallel glass tubes 31 and 32 interconnected at each end.
  • the glass tubes each have an internal diameter of 25.4 millimetres (one inch).
  • the inlet ends of the first and second passageways 4 and 5 are coupled to an inlet glass bell jar 33.
  • the outlet ends of the first and second passageways 4 and 5 are coupled to an outlet bell jar 34.
  • the outlet bell jar 34 is coupled via glass tubing to any suitable particle size determining means (in this example a Malvern MuItiSizer or particle cell manufactured by Malvern Instruments of Malvern, England, the United Kingdom) 35 which is capable of detecting particles emitted in the air stream and of determining the mass distribution within the emitted particles.
  • An outlet tube 36 coupled to the outlet of the Malvern particle cell 35 is coupled to a suitable pump or other means 37 for causing an airflow through the test apparatus 30.
  • Electrically conductive members 38 and 39 run along the length of the glass tubes 31 and 32 and are coupled to the negative and positive high tension voltage sources 26 and 27, respectively.
  • a lighted cigarette 38 was introduced into the 5 inlet bell jar 33 to ensure a good supply of particles within the incoming air stream 3 and the pump 37 was operated to produce a flow of 150 m 3 h "1 (metres cubed per hour).
  • the mass distribution of particles in the air stream emitted from the bell jar 34 was measured firstly for the case where no voltages were applied to the electrically conductive members 38 and 39 and secondly for the case when the appropriate ⁇ o voltages were applied to these members 38 and 39.
  • the voltages applied by the sources 26 and 27 were - 10 KV (kilo volts) and + 10 KV, respectively.
  • Figure 6 illustrates the mass distribution of particles in the air stream emitted from the bell jar 34 when no voltages are applied through the electrically conductive members
  • Figure 7 illustrates the corresponding results when the appropriate positive and negative 10KV voltages were applied to the electrically conductive members 38 and 39.
  • the peak of the distribution has not been reached and in fact the measurements went off-scale above about 100 micrometres.
  • the mass distribution is shown as a percentage against 0 a logarithmic scale of particle size in micrometres ( ⁇ m).
  • the results shown in Figure 6 and 7 are typical of several tests and are reproducible.
  • FIG. 6 A comparison of Figures 6 and 7 shows that a very large increase in the average particle size occurs when the charging chamber 24 is operational, that is when the 5 positive and negative high voltage sources 26 and 27 are applied to the appropriate ones of the electrically conductive members 38 and 39, even though the test apparatus 30 is not optimised.
  • the particle size distribution has a Gaussian-like nature and peaks at about 0.5 to 0.6 0 micrometres whereas when the high voltage sources are applied as shown in Figure 7, the minimum particle size measured is about 20 micrometres.
  • a smaller filtering means with an external diameter of 156 millimetres and an internal diameter of 45 millimetres, an axial length of 50 millimetres and with the channels 10a formed by corrugations of 3 millimetres is used with the centrifuge 15 this time being rotated at a speed of about 200 rpm (revolutions per minute) using a 20 W (watt) motor and there is again a flow rate through the apparatus 1 of about 200 metres cubed of air per hour (200m 3 h "1 ), then, with the charging chamber 24 absent or not operational, the apparatus is capable of removing virtually all particles with a dimension of 10 micrometres or greater but only removes 23.4% of particles with a size between 10 and 1 micrometres, only 1.8% of particles of a size between 0.3 and 1 micrometres and only 0.5% of particles with a size between 0.3 and 0.1 micrometres. In contrast, when the charging chamber 24 is operational, the same apparatus is capable of removing virtually all particles of 0.1 micrometres or greater in size entering the apparatus.
  • the present invention should allow the size of the particles which can be removed from the airstream entering the apparatus to be reduced or should allow the use of smaller filtering means and lower power motors, if desired.
  • the filtering means 10 shown in the drawings could be replaced by a further chamber or so-called cyclone 100 which, as shown schematically in Figures 8a and 8b, may be in the form of a hollow body 100b having an inner surface 100a which is rotationally symmetric about an axis A extending through the body.
  • Fluid from the mixing chamber 9 is directed into the cyclone 100 through an inlet 100c shaped to cause the air to be tangentially incident on the inner surface 100a so that particles in the air are thrown radially outwards so hitting the inner surface 100a and either 5 sticking to the inner surface 100a or dropping out of the fluid to an appropriate collection area 100d. Cleaned air exits via outlet 100e.
  • a separate means such as a fan for causing an air flow through the apparatus may be required in this example.
  • the filtering means could simply be a static filter formed of one or more layers of a suitable filtering material positioned between the charging chamber 24 and the outlet of the apparatus 1 with a fan or similar suction device generally positioned on the
  • - charging chamber 24 with the static filtering means should allow the removal of particles with a smaller diameter than was previously possible without the charging chamber 24.
  • Any suitable material may be used to form the static filter such as, for
  • HEPA High Efficiency Particulate Air
  • the incorporation of the charging chamber 24 may allow for a lower grade of such filter material to be used so reducing costs and reducing the pressure drop through
  • 30 chamber 24 in apparatus using such a filtering means enables particles of a size between 0.1 and 1 ⁇ m to be completely removed. If a lower grade 65% ASHRAE filter is used without the charging chamber, then particles of a size down to 10 micrometre (10 ⁇ ) may be removed with a 100% efficiency but the efficiency drops to 45% for particles of a size between 10 and 0.1 ⁇ m. Using the charging chamber
  • 35 24 in apparatus with such a 65% ASHRAE filter enables particles of a size between 0.1 and 10 ⁇ m to be completely removed.
  • the present invention allows a lower grade of filter to be used and still enables particles down to 0.1 ⁇ m to be efficiently removed.
  • the use of a lower grade filter means that the pressure drop across the filtering means is reduced (from 340 to 25 Po, in this case) so enabling a corresponding reduction in the power required to produce the desired air flow through the apparatus (from 25 to 1.04 Watts, in this case).
  • the mixing chamber will generally incorporate deflection blades or other means as discussed above for facilitating mixing of oppositely charged particles.
  • the charging chamber has been formed so as to define first and second passageways 4 and 5 within which particles attain negative and positive charges, respectively. It may, however, be possible to charge some particles negatively and some particles positively within the same passageway by, for example, using an AC (alternating current) voltage source instead of the two DC voltage sources 26 and 27 so that an alternating voltage is applied to an electrically conductive member and synchronising the frequency of the AC voltage with the flow rate through the passageway so that the voltage changes from one polarity to the other opposite polarity as a packet of air previously charged with the one polarity is just leaving the passageway. In such circumstances, some agglomeration may occur within the passageway.
  • AC alternating current
  • first and second passageways 4 and 5 are provided as discussed above, it may be advantageous to be able to reverse the polarities of the applied voltages occasionally so as to attract away from the walls 25a any previously charged particles which may have inadvertently become stuck the walls 25a of the passageways 4 and 5.
  • the electrically conductive members 28 and 29 extend generally longitudinally of the passageways 4 and 5 in the direction of the airflow through the passageways, any suitable form or shape of electrically conductive member may be used.
  • the electrically conductive members could extend generally transversely of the direction of the airflow or one or more electrically conductive members or needles spaced along the lengths of the passageways could project into the passageways 4 and 5 from the walls 25a.
  • the electrically conductive members should of course be sufficiently well-spaced to avoid any detrimental shielding effects.
  • the present invention is applicable, inter alia, to the manufacture of air cleaning apparatus for home, office, laboratory or factory application.

Landscapes

  • Electrostatic Separation (AREA)

Abstract

L'invention concerne une chambre de charge (24) comprenant un appareil (7, 8) provoquant le passage de particules à travers la chambre de charge (24) depuis un orifice (6) situé dans l'appareil de façon à produire une charge électrique d'une certaine polarité et permettant à d'autres particules de produire une charge électrique de polarité opposée à la première. Une chambre (9) de mélange (9) communique avec la chambre de charge (24) de façon à assurer le mélange des particules de charge opposée traversant l'appareil de mélange (24) et de former des particules de plus grande taille. Une installation de filtration (10) placée entre la chambre de mélange (9) et l'une des sorties (11) de l'appareil (1) permet d'enlever les particules du fluide traversant la chambre de mélange (9) avant que le fluide atteigne l'orifice (11). On provoque ainsi la combinaison ou l'agglomération des particules contenues dans le fluide traversant l'appareil (1) avec d'autres particules de charge opposée, de manière à former des particules de plus grande taille plus faciles à filtrer, ce qui permet d'utiliser un dispositif de filtration moins onéreux ou bien d'enlever des particules plus petites de l'écoulement fluide.
PCT/IB1994/000436 1993-12-22 1994-12-21 Appareil permettant d'enlever des particules d'un fluide WO1995017239A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9326121.2 1993-12-22
GB939326121A GB9326121D0 (en) 1993-12-22 1993-12-22 Apparatus for removing particles from a fluid

Publications (1)

Publication Number Publication Date
WO1995017239A1 true WO1995017239A1 (fr) 1995-06-29

Family

ID=10746983

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB1994/000436 WO1995017239A1 (fr) 1993-12-22 1994-12-21 Appareil permettant d'enlever des particules d'un fluide

Country Status (2)

Country Link
GB (1) GB9326121D0 (fr)
WO (1) WO1995017239A1 (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL1003157C2 (nl) * 1996-05-17 1997-11-18 Romico Hold A V V Roterende deeltjesscheider met hoge afscheidingsgraad.
FR2829041A1 (fr) * 2001-07-06 2003-03-07 Chi Chin Yu Epurateur d'air electrostatique
EP1596987A2 (fr) * 2003-02-12 2005-11-23 Innovative Defense Technologies Ltd Procede et construction de filtres et de prefiltres destines a allonger le cycle de vie des corps de filtre dans ces corps
NL2000350C2 (nl) * 2006-12-01 2008-06-03 Romico Hold A V V Inrichting en werkwijze voor het in fracties scheiden van een stromend mediummengsel.
GB2479760A (en) * 2010-04-21 2011-10-26 Dyson Technology Ltd Conditioning air using an electrical influence machine
CN103244387A (zh) * 2012-02-06 2013-08-14 戴森技术有限公司 风扇
US9089247B2 (en) 2010-04-21 2015-07-28 Dyson Technology Limited Surface treating appliance
CN112843973A (zh) * 2021-03-03 2021-05-28 武汉利康能源有限公司 微尘聚并装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3533222A (en) * 1965-09-01 1970-10-13 Mediterranea Compagnia Ind Com De-dusting device for smoke and other gaseous fluids
US4162144A (en) * 1977-05-23 1979-07-24 United Air Specialists, Inc. Method and apparatus for treating electrically charged airborne particles
WO1984001523A1 (fr) * 1982-10-20 1984-04-26 Bosch Gmbh Robert Procede et dispositif de purification de gaz
WO1984004052A1 (fr) * 1983-04-19 1984-10-25 Bosch Gmbh Robert Procede et dispositif pour purifier des gaz de leurs particules electriquement conductrices
EP0532105A2 (fr) * 1991-09-09 1993-03-17 Koninklijke Philips Electronics N.V. Dépoussiéreur
WO1994023823A1 (fr) * 1993-04-16 1994-10-27 Romico Hold A.V.V. Separateur de particules rotatif a conduits de separation non paralleles, et unite de separation

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3533222A (en) * 1965-09-01 1970-10-13 Mediterranea Compagnia Ind Com De-dusting device for smoke and other gaseous fluids
US4162144A (en) * 1977-05-23 1979-07-24 United Air Specialists, Inc. Method and apparatus for treating electrically charged airborne particles
WO1984001523A1 (fr) * 1982-10-20 1984-04-26 Bosch Gmbh Robert Procede et dispositif de purification de gaz
WO1984004052A1 (fr) * 1983-04-19 1984-10-25 Bosch Gmbh Robert Procede et dispositif pour purifier des gaz de leurs particules electriquement conductrices
EP0532105A2 (fr) * 1991-09-09 1993-03-17 Koninklijke Philips Electronics N.V. Dépoussiéreur
WO1994023823A1 (fr) * 1993-04-16 1994-10-27 Romico Hold A.V.V. Separateur de particules rotatif a conduits de separation non paralleles, et unite de separation

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL1003157C2 (nl) * 1996-05-17 1997-11-18 Romico Hold A V V Roterende deeltjesscheider met hoge afscheidingsgraad.
WO1997044117A1 (fr) * 1996-05-17 1997-11-27 Romico Hold A.V.V. Separateur de particules rotatif
FR2829041A1 (fr) * 2001-07-06 2003-03-07 Chi Chin Yu Epurateur d'air electrostatique
EP1596987A4 (fr) * 2003-02-12 2009-01-21 Innovative Defense Technologie Procede et construction de filtres et de prefiltres destines a allonger le cycle de vie des corps de filtre dans ces corps
EP1596987A2 (fr) * 2003-02-12 2005-11-23 Innovative Defense Technologies Ltd Procede et construction de filtres et de prefiltres destines a allonger le cycle de vie des corps de filtre dans ces corps
NL2000350C2 (nl) * 2006-12-01 2008-06-03 Romico Hold A V V Inrichting en werkwijze voor het in fracties scheiden van een stromend mediummengsel.
WO2008082291A1 (fr) * 2006-12-01 2008-07-10 Romico Hold A.V.V. Dispositif et procédé de séparation d'un mélange de milieu fluide en fractions
GB2479760A (en) * 2010-04-21 2011-10-26 Dyson Technology Ltd Conditioning air using an electrical influence machine
GB2479760B (en) * 2010-04-21 2015-05-13 Dyson Technology Ltd An air treating appliance
US9089247B2 (en) 2010-04-21 2015-07-28 Dyson Technology Limited Surface treating appliance
CN103244387A (zh) * 2012-02-06 2013-08-14 戴森技术有限公司 风扇
CN103244387B (zh) * 2012-02-06 2017-05-24 戴森技术有限公司 风扇
CN112843973A (zh) * 2021-03-03 2021-05-28 武汉利康能源有限公司 微尘聚并装置
CN112843973B (zh) * 2021-03-03 2024-06-11 武汉利康能源有限公司 微尘聚并装置

Also Published As

Publication number Publication date
GB9326121D0 (en) 1994-02-23

Similar Documents

Publication Publication Date Title
US7297185B2 (en) Electrostatic dust precipitator
EP1892044B1 (fr) Dépoussiéreur électrostatique
JP5039816B2 (ja) フィルタ
JP5421204B2 (ja) 分離装置
KR101669295B1 (ko) 공기 정화 효율을 향상시키기 위한 장치, 시스템 및 방법
CN107842933A (zh) 一种基于微分毛刷摩擦起电原理的高效静电除尘装置
KR101882283B1 (ko) 정전분무 싸이클론 공기청정기
KR100308333B1 (ko) 마찰 정전기 집진장치
WO2006092702A2 (fr) Purificateur d'air pollue par des poussieres fines et procede de purification associe
WO1995017239A1 (fr) Appareil permettant d'enlever des particules d'un fluide
KR20180086899A (ko) 집진 유닛 및 이를 포함하는 공기정화장치
CN207584924U (zh) 一种基于微分毛刷摩擦起电原理的高效静电除尘装置
JPS61209062A (ja) 多段集塵ユニツトを有する電気集塵装置
JP2004141826A (ja) 電気集塵器
US5149339A (en) Rotary device for removing particulates from a gas stream
JPH05161859A (ja) 空気清浄装置
US4940471A (en) Device for cleaning two-stage electrostatic precipitators
US4948397A (en) Method, means and device for separation of particulate matter from a carrier medium
KR20220025430A (ko) 재생 가능한 정전 필터, 정전 필터 재생 시스템 및 정전 필터 재생 시스템을 구비한 공기 청정기
EP3013204B1 (fr) Aspirateur avec filtre électrostatique
CN219187322U (zh) 油烟废气自清洁旋风净化器
JP2000046358A (ja) 静電式空気清浄装置
CN214746302U (zh) 电净化装置及空气净化器
JPS6287262A (ja) 空気清浄装置
JPH05168974A (ja) 空気清浄装置

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): JP US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE

121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase
122 Ep: pct application non-entry in european phase