WO1994003276A1 - Electrostatic filter - Google Patents
Electrostatic filter Download PDFInfo
- Publication number
- WO1994003276A1 WO1994003276A1 PCT/IE1993/000042 IE9300042W WO9403276A1 WO 1994003276 A1 WO1994003276 A1 WO 1994003276A1 IE 9300042 W IE9300042 W IE 9300042W WO 9403276 A1 WO9403276 A1 WO 9403276A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- woven
- electrostatic
- filter
- air
- weft
- Prior art date
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D39/00—Filtering material for liquid or gaseous fluids
- B01D39/08—Filter cloth, i.e. woven, knitted or interlaced material
- B01D39/083—Filter cloth, i.e. woven, knitted or interlaced material of organic material
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D39/00—Filtering material for liquid or gaseous fluids
- B01D39/14—Other self-supporting filtering material ; Other filtering material
- B01D39/16—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres
- B01D39/1669—Cellular material
- B01D39/1676—Cellular material of synthetic origin
-
- 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
- B03C3/28—Plant or installations without electricity supply, e.g. using electrets
-
- 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
- B03C3/28—Plant or installations without electricity supply, e.g. using electrets
- B03C3/30—Plant or installations without electricity supply, e.g. using electrets in which electrostatic charge is generated by passage of the gases, i.e. tribo-electricity
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
- B01D2239/04—Additives and treatments of the filtering material
- B01D2239/0442—Antimicrobial, antibacterial, antifungal additives
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
- B01D2239/04—Additives and treatments of the filtering material
- B01D2239/0464—Impregnants
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
- B01D2239/06—Filter cloth, e.g. knitted, woven non-woven; self-supported material
- B01D2239/065—More than one layer present in the filtering material
Definitions
- the present invention relates to woven electrostatic material and in particular to an air filter comprising such woven electrostatic material.
- the filter comprises two pairs of woven electrostatic material layers, typically polypropylene. Each pair of layers comprise a first layer of material that will develop a positive charge and a second layer of material that will develop a negative charge in response to an air flow therethrough.
- the air flow entry side of such a filter comprises a first pair of layers where the positively chargeable layer of woven material is outwardly disposed.
- the exit side comprises a second pair of layers where the negatively charged layer of said material is outwardly disposed.
- a foam material for example, a polyurethane material which also has electrostatic properties.
- Prior art electrostatic air filters are known to have certain disadvantages. Firstly, due to the electrostatic charge, dust particles adhere to the woven material blocking its pores and thus restrict air flow. Furthermore, due to the build-up of dust particles on said woven material, the electrostatic charge tends to decrease within a relatively short period of time. Additionally, due to the restricted air flow and the build-up of dust particles in the filter, a breeding ground for bacteria, fungi, yeasts and other micro-organisms may be provided.
- the present invention provides a woven electrostatic material characterised in that the material comprises a warp of negatively or positively chargeable material and a weft of oppositely chargeable material, which warp and weft are interwoven to form a material having the combined electrostatic characteristics of both a positively and negatively charged material.
- the woven material is impregnated with at least one microbiological growth control agent.
- the growth control agent or agents is or are selected from the group comprising fungicides, fungistats, biocides, biostats, bactericides and bacteriostats.
- the warp and the weft each comprise polypropylene.
- the present invention further provides an air filter comprising first and second layers of a woven electrostatic material characterised in that said electrostatic material comprises an interwoven negatively or positively chargeable warp and an oppositely chargeable weft, said layers of woven electrostatic material being separated by an intermediate air permeable material.
- the or each layer of woven material and/or the intermediate material is or are impregnated with a microbiological growth control agent.
- the woven material comprises an anti-clogging means for filtering dust particles from the air flow path, and the air filter further comprises a collecting tray for collecting dust particles repelled from the electrostatic material.
- the intermediate air permeable material comprises an electrostatic medium.
- the intermediate material comprises woven polypropylene, open-cell polyurethane or polyester.
- the layers of woven material and the intermediate air permeable material are housed in a retaining frame, whereby the filter may be installed in a bi-directional air flow system or without consideration to air flow direction in a uni-directional system so as to provide a reversible filter.
- Figure 1 is a partially cut-away perspective view of a filter
- Figure 2 is a diagrammatic front elevation of a portion of a layer of electrostatic woven material.
- Figure 1 shows a perspective view of a filter housed in a metal frame 10.
- the filter elements are held within the frame 10 by a wire mesh 12.
- the first filter element 21 comprises a layer of interwoven positively and negatively chargeable materials comprising a warp of negatively or positively chargeable material and a weft of oppositely chargeable material. The warp and weft are interwoven to form a material which displays the combined electrostatic characteristics of a pair of separate positively and negatively chargeable layers.
- a second filter element 22 comprises a layer of polyester material which may optionally be substituted by an open-cell polyurethane block or a polypropylene block.
- the third filter element 23 comprises an interwoven layer similar to that of the first layer.
- the first layer 21 and third layer 23 comprise warps and wefts of polypropylene fibres which have a microbiological growth control agent impregnated therein.
- the microbiological growth control agent is selected to have high efficiency against fungi, yeasts or bacteria, particularly gram-positive and/or gram-negative bacteria.
- the microbiological growth control agent is selected for its action and is one or more of the following: fungicide, fungistat, biocide, biostat, bactericide bacteriostat and similar agents.
- Suitable control agents are well known to those skilled in the microbiological growth control art. Quantities used for required control depend on the selected agent. Such agents may include Microban (Microban Products Company), Micro-Chek (Ferro Corporation), Biosperse (Ashland Chemical Company), Biomate (Dearborn Chemicals Ltd.) and Fungi ex (Ciba Geigy PLC) .
- the preferred microbiological growth control agent comprises Microban (Microban Products Company, 9801 Kincey Avenue, Suite 100, Huntersville, NC 28078, United States of America).
- the filter of the present invention may be used as a general purpose air filter for use in office or home environments. Tests conducted indicate an efficiency of 96.5% in extraction of dust particles from the air stream. The elimination of gram-positive and gram-negative bacteria and various fungi and yeasts from the air reduces the risk of development of a number of potentially hazardous conditions.
- So-called "sick building” syndrome has been attributed to airborne bacteria, in association with several other biological factors such as fungi and yeasts.
- the present filter aims to eliminate one or more of those biological factors.
- FIG. 2 illustrates an interwoven material 100 of the present invention.
- the weft 110 is represented by a thick line (which does not represent the thickness of the individual fibres or filaments) and the warp 120 is represented by a thin line for clarity. Either the weft 110 or the warp 120 is selected to develop a positive electrostatic charge and the other fibres or filaments are selected to develop an opposite charge.
- the material 100 combines the electrostatic characteristics of a positively charged and negatively charged pair of layers in one layer.
- the extraction of dust particles from the air stream occurs in the same way as with separately charged sheets but clogging does not tend to occur.
- a high electrostatic field gradient between the weft 110 and warp 120 of the material 100 dislodges dust particles which aggregate on the surface and then fall under gravity into a collection area within the filter frame 10.
- This anti-clogging mechanism allows the weft 110 and warp 120 to retain their electrostatic charges for a relatively long period of time.
- This arrangement provides a filter which is still electrostatically active after a period in which there is no air flow.
- each electrostatic element, the weft 110, the warp 120 and the intermediate air permeable material block 22, comprise self-charging electrostatic media.
- a depressed electrostatic charge is revitalised when charge is developed by an air flow through the filter.
Abstract
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU45814/93A AU4581493A (en) | 1992-07-30 | 1993-07-30 | Electrostatic filter |
EP93916131A EP0656816A1 (en) | 1992-07-30 | 1993-07-30 | Electrostatic filter |
IE083993 IES61249B2 (en) | 1992-07-30 | 1993-11-01 | Improved filter |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IE922503 | 1992-07-30 | ||
IE922503 | 1992-07-30 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1994003276A1 true WO1994003276A1 (en) | 1994-02-17 |
Family
ID=11039716
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/IE1993/000042 WO1994003276A1 (en) | 1992-07-30 | 1993-07-30 | Electrostatic filter |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0656816A1 (en) |
AU (1) | AU4581493A (en) |
WO (1) | WO1994003276A1 (en) |
ZA (1) | ZA935518B (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1995033569A1 (en) * | 1994-06-07 | 1995-12-14 | Freshman Ab | A device for separating extremely fine particles from air |
EP1008390A1 (en) * | 1998-12-08 | 2000-06-14 | Firma Carl Freudenberg | Air cleaner system from dust,eg pollen-dust |
US8182580B2 (en) | 2006-05-18 | 2012-05-22 | Valtion Teknillinen Tutkimuskeskus | Filter structure for filtering a particle-containing gas, method of its manufacture and use of porous paper |
CN105195325A (en) * | 2014-06-03 | 2015-12-30 | 中国人民大学 | Application of lithium niobate pyroelectric material in atmospheric particulate adsorption on basis of temperature control |
WO2018036890A1 (en) * | 2016-08-26 | 2018-03-01 | Green Impact Holding Ag | Wash-durable face mask with antimicrobial properties and/or improved washability |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2374938A1 (en) * | 1976-12-21 | 1978-07-21 | Marret Yves | Electrostatic action filter for dust-laden air - includes woven filter meshes with material that is charged by air friction |
US4944854A (en) * | 1983-11-08 | 1990-07-31 | Celanese Corporation | Electret process and products |
US5037455A (en) * | 1990-09-14 | 1991-08-06 | The Great American Filter Company | Air filter |
EP0447166A2 (en) * | 1990-03-12 | 1991-09-18 | Mitsui Petrochemical Industries, Ltd. | Process for producing an electret, a film electret, and an electret filter |
-
1993
- 1993-07-30 ZA ZA935518A patent/ZA935518B/en unknown
- 1993-07-30 AU AU45814/93A patent/AU4581493A/en not_active Abandoned
- 1993-07-30 EP EP93916131A patent/EP0656816A1/en not_active Ceased
- 1993-07-30 WO PCT/IE1993/000042 patent/WO1994003276A1/en not_active Application Discontinuation
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2374938A1 (en) * | 1976-12-21 | 1978-07-21 | Marret Yves | Electrostatic action filter for dust-laden air - includes woven filter meshes with material that is charged by air friction |
US4944854A (en) * | 1983-11-08 | 1990-07-31 | Celanese Corporation | Electret process and products |
EP0447166A2 (en) * | 1990-03-12 | 1991-09-18 | Mitsui Petrochemical Industries, Ltd. | Process for producing an electret, a film electret, and an electret filter |
US5037455A (en) * | 1990-09-14 | 1991-08-06 | The Great American Filter Company | Air filter |
Non-Patent Citations (2)
Title |
---|
PATENT ABSTRACTS OF JAPAN vol. 13, no. 158 (C-586)17 April 1989 * |
PATENT ABSTRACTS OF JAPAN vol. 14, no. 30 (C-678)(3973) 19 January 1990 * |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1995033569A1 (en) * | 1994-06-07 | 1995-12-14 | Freshman Ab | A device for separating extremely fine particles from air |
EP1008390A1 (en) * | 1998-12-08 | 2000-06-14 | Firma Carl Freudenberg | Air cleaner system from dust,eg pollen-dust |
US8182580B2 (en) | 2006-05-18 | 2012-05-22 | Valtion Teknillinen Tutkimuskeskus | Filter structure for filtering a particle-containing gas, method of its manufacture and use of porous paper |
CN105195325A (en) * | 2014-06-03 | 2015-12-30 | 中国人民大学 | Application of lithium niobate pyroelectric material in atmospheric particulate adsorption on basis of temperature control |
WO2018036890A1 (en) * | 2016-08-26 | 2018-03-01 | Green Impact Holding Ag | Wash-durable face mask with antimicrobial properties and/or improved washability |
Also Published As
Publication number | Publication date |
---|---|
AU4581493A (en) | 1994-03-03 |
ZA935518B (en) | 1994-02-24 |
EP0656816A1 (en) | 1995-06-14 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US8091551B2 (en) | Facemask with filtering closure | |
US5038775A (en) | Plastic scrim | |
US5906677A (en) | Electrostatic supercharger screen | |
US5037455A (en) | Air filter | |
US5312467A (en) | Air filter assembly | |
US3763633A (en) | Electrostatic air filter | |
US4323374A (en) | Air filter assembly | |
EP2456536B1 (en) | Filter media construction using ptfe film and carbon web for hepa efficiency and odor control | |
US5766288A (en) | Multilayered deep-bed filter material | |
AU764615B2 (en) | Biostatic air filter | |
US3017239A (en) | Air conditioner filters having germicidal properties | |
US20070175192A1 (en) | Pleated hybrid air filter | |
US20140157990A1 (en) | Antimicrobial Filter Medium and Filter Module | |
WO1998017368A1 (en) | High efficiency permanent air filter | |
EP0679424A1 (en) | Air filter assembly | |
NO882394L (en) | FILTER KIT. | |
WO2006014182A1 (en) | Fluid filter | |
WO2004041408A1 (en) | High capacity hybrid multi-layer automotive air filter | |
WO1994003276A1 (en) | Electrostatic filter | |
GB2036591A (en) | Multi layer air filter bag | |
US3853510A (en) | Two stage high efficiency air filter | |
EP0779839A1 (en) | A device for separating extremely fine particles from air | |
IES61249B2 (en) | Improved filter | |
US5874373A (en) | Enhanced electret needled filtration media and composites | |
ATE189192T1 (en) | GERMAN PROTECTION FOR HOUSEHOLD WATER FILTER SCREEN INSERTS |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AU CA FI HU JP KR NO NZ PL RU UA 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 BF BJ CF CG CI CM GA GN ML MR NE SN TD TG |
|
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 1993916131 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 1993916131 Country of ref document: EP |
|
NENP | Non-entry into the national phase |
Ref country code: CA |
|
WWR | Wipo information: refused in national office |
Ref document number: 1993916131 Country of ref document: EP |
|
WWW | Wipo information: withdrawn in national office |
Ref document number: 1993916131 Country of ref document: EP |