Abstract: The air cleaner has a minus ion generator and a positive electrode. The minus ion generator carries a high minus voltage, and the positive electrode carries a high plus voltage. Preferably, the minus ion generator has a heater. The air cleaner may have an absorbing sheet positioned close to the positive electrode. Preferably, the minus ion generator is apart from the positive electrode by a distance not less than a half of the maximum distance between walls of room. Preferably, the high plus voltage is not less than 4,000 Volts, and the absolute value of the high minus voltage is larger than the absolute value of the high plus voltage. Preferably, the air cleaner has a sterilizing function.

Abstract: A device for cleaning static precipitator in which hot air and steam are repeatedly filled into an oil-collecting sink of the static precipitator at different times or at the same time for heating and melting the oil dirt attaching to the static panels, making the oil dirt drop down into a collecting section. The static panels can be harmlessly cleaned up without disassembly or using any scraper. Hot air also serves to shorten the drying time for the static panels.

Abstract: The invention concerns a filter insert for separating oil out of a flow of gas; the filter insert (1) comprising a pure gas side (2) and an untreated gas side (3) as well as support means (4) and at least two separation zones (5; 6) of different degrees of fineness.

Abstract: A method of removing dust from dust laden gases said method including the sequential steps of: (1) passing a flow of gases laden with dust particles, at a selected first gas stream velocity through a first dust removing mechanism capable of creating multiple vortexes of gases; (2) agglomerating the dust particles of the gases as they pass through the first dust removing mechanism said first gas stream velocity being selected to cause agglomeration of said dust particles; (3) passing the gas stream carrying agglomerated particles at a selected second gas stream velocity through a second dust removing mechanism capable of creating multiple vortexes of gases; (4) removing the agglomerated dust particles as they pass through the second dust removing mechanism at said second gas stream velocity; wherein the second gas stream velocity is substantially slower than the first gas stream velocity.

Abstract: The process serves for removing carbon monoxide and/or hydrogen from an air stream by catalytic oxidation. Dusts and/or aerosols of a particle size of less than 20 &mgr;m are removed from the air stream upstream of the catalytic oxidation.

Abstract: A vacuum cleaner having a reduced velocity chamber with a high velocity air inlet, an electric motor, a rotary mechanism driven by the motor for creating a vacuum in the chamber, an outlet for exhausting air from the chamber, which air flows in a selected path from the air inlet, through the chamber and out the air exhaust outlet and a disposable porous sheet filter layer in the chamber for removing large solid particles from the air. The vacuum cleaner also has an improved filter, wherein the improved filter includes a layer of material to remove very fine air particles and a layer of material to remove odors from the air.

Abstract: The invention is directed to a mobile arrangement for cleaning contaminated air. The arrangement has a blower unit, a filter unit, supply air lines and discharge air lines. During the cleaning process, surrounding air is sucked in by the blower unit, guided through the filter for cleaning, and finally guided out of the arrangement again. The filter unit (2) has at least one cylindrical filter element (15, 16, 17) in which an activated charcoal filter (17) is arranged at the outer side of the cylinder jacket and a solids filter (15, 16) is arranged at the inner side of the cylinder jacket.

Abstract: A smoke and odor purifying system which can be incorporated within a housing that can serve both as a table centerpiece and an ashtray. The system having an esthetically pleasing flower vase construction with petal shaped appendages for resting of cigarettes or the like. A floral arrangement is made up of individual artificial flowers. Each flower having an opening in the bud for drawing in smoke-filled air and passing it through the system. Also defined within the petals of the housing are a plurality of intake openings through which cigarette smoke, as well as secondary smoke from the surrounding area may be drawn downwardly through the device. An electrically or battery powered fan means, positioned below a filtration and odor-treatment system, drives the smoke through the system which includes an electrostatic prefiltering bed followed by an activated charcoal bed, an H.E.P.A. filter and finally another activated charcoal bed containing an air freshening material.

Abstract: Gas scrubbing apparatus and method, employing highly charged liquid droplets for removal of both particulates and pollutant gases from the gas to be cleaned, allowing scrubbing of uncharged particulates by means of monopole--dipole attractive forces between the charged liquid droplets and the electric dipoles induced in the uncharged particulates by the charged droplets; employing electrode geometry at the site of droplet production and charging, having spreading liquid sheet electrodes emitting the droplets from the edges of the liquid sheets, interspersed with electrically conductive induction electrodes, with electrostatic potential of no more than about 20 kv existing between the induction electrode array and the array of liquid sheets, and with spacing such that adequately high electric field strength can be maintained at the edges of the liquid sheets to allow adequate charging of the droplets emitted from the liquid sheets, without the occurrence of corona discharges which could deplete droplet charges

Abstract: An electrostatic bag filter unit is formed of a plurality of sections arranged in series. One section is a bag filter section containing a plurality of parallel elongated filter fabric bag elements extending across and traverse to a gas flow path therethrough and a plurality of grounded, electrically-conductive support frames, each support frame being internal to and supporting one of the filter fabric bag elements. Optionally, the bag filter section may further include a plurality of non-discharging electrodes disposed parallel to and interspersed among the filter fabric bag elements. A filter precharger section is located immediately upstream of and contiguous with the bag filter section and is formed of a linear array of alternating corona discharge electrodes and grounded electrodes arranged perpendicular to the gas flow path.

Abstract: A vacuum cleaner having a reduced velocity chamber with a high velocity air inlet, an electric motor, a rotary mechanism driven by the motor for creating a vacuum in the chamber, an outlet for exhausting air from the chamber, which air flows in a selected path from the air inlet, through the chamber and out the air exhaust outlet and a disposable porous sheet filter layer in the chamber for removing large solid particles from the air. The vacuum cleaner also has an improved filter, wherein the improved filter includes a layer of material to remove very fine air particles and a layer of material to remove odors from the air.

Abstract: A frameless electrostatic air filter used in heating and air conditioning systems includes a plurality of filter media layers and an internal support grill and has no external support grill or frame. The frameless electrostatic air filter has an internal support grill to support the filter media layers and a fabric edging that is secured in place all the way around the edge of the frameless electrostatic air filter. The center of the frameless electrostatic air filter is secured with a plastic rivet. The frameless electrostatic air filter seats and seals tight to the inside lip of filter receptacles.

Abstract: An oxygen generating system includes an oxygen generator having an oxygen ion conducting honeycomb structure and a heat exchanger thermally coupled to the oxygen generator. The system also includes a heater thermally coupled to the oxygen generator and a control module coupled to the oxygen generator and the heater. The control module monitors one or more of the system parameters and dynamically controls the oxygen generating system in response to the one or more system parameters such as, for example, varying the speed of a draft fan in the outlet waste air stream. A method of operating an oxygen generating system includes initializing the oxygen generating system in response to an operation status request and generating oxygen in an oxygen ion conducting honeycomb structure in response to a desired oxygen flow rate input.

Abstract: A filter apparatus for use in a forced air ventilation system, the filter apparatus having a first fan folded sheet of a washable first type of filter material, a second fan folded sheet of a second type of filter material, and fanfolds of the first and second fan folded sheets are substantially equally shaped and folded together such that the fanfolds of the first and second fan folded sheets are interdigitated to form a filter material assembly. The first type of filter material is preferably an electrostatically self-charging washable material such as woven polypropylene and the second type of filter material is preferably disposable and contains activated charcoal. The filter material assembly may be removably disposed in a rectangular filter frame for mounting the filter material assembly in the forced air system. The filter frame has at least one crank shaft rotatably deposed between two opposed side walls which are between an open front end and an open back end of the frame.

Abstract: A frameless electrostatic air filter used in heating and air conditioning systems includes a plurality of filter media layers and an internal support grill and has no external support grill or frame. The frameless electrostatic air filter has an internal support grill to support the filter media layers and a fabric edging that is secured in place all the way around the edge of the frameless electrostatic air filter. The center of the frameless electrostatic air filter is secured with a plastic rivet. The frameless electrostatic air filter seats and seals tight to the inside lip of filter receptacles.

Abstract: A particle separator having a housing, a radially centered core, helical augers which force a fluid stream in a helical flow direction, and separator devices for the progressive separation of particles from a particulate contaminated fluid stream.

Abstract: An air-cleaning apparatus is mounted on a wall to collect particulates suspended in the air through electrical control. In the air-cleaning apparatus, a box is mounted on a wall to house therein a dust-collection unit and an air fan such as cross-flow fan for blowing air. The dust-collection unit collects the particulates suspended in the air by imparting a corona electric charge to these particulates, i.e., by rendering them an electrostatic charge. The box of the air-cleaning apparatus is provided with an air outlet in its lower section and also provided with a forward-protruding air duct in its upper section. The forward-protruding air duct is provided with an air inlet in its leading edge portion.

Abstract: A device and method for controlling particulate air pollutants of the present invention combines filtration and electrostatic collection devices. The invention includes a chamber housing a plurality of rows of filter elements. Between each row of filter elements is a grounded plate. Between the grounded plates and the filter elements are electrode grids for creating electrostatic precipitation zones between each row of filter elements. In this way, when the filter elements are cleaned by pulsing air in a reverse direction, the dust removed from the bags will collect in the electrostatic precipitation zones rather than on adjacent filter elements.

Abstract: A method and apparatus for preventing contamination of a substrate or a substrate surface, and particularly relates to prevention of contamination of raw materials, semi-finished products, base materials of products and substrate surface in a high-tech industry such as in the production of semiconductors and liquid crystals. A gas coming into contact with a base material or substrate is purified by dust removing apparatus and adsorption and/or absorption apparatus so that the concentration of fine particles in the gas is below class 1,000 and a non-methane hydrocarbon concentration is below 0.2 ppm. Thereafter, the base material or the substrate surface is exposed to this gas.

Abstract: An electrostatic supercharger screen (10) is within an air flow duct (12) in front of a standard air filter (14), between a furnace/cooling unit (16) and an air vent grill (18) in a wall (20) of a building (22). The screen (10) includes an element (24) for removing small microns of particles in air that goes past the standard air filter (14) within the air flow duct (12), so as to help clean the air of pollens, smoke, odors and bacteria. A structure (26) is for supporting the removing element (24) parallel to the standard air filter (14). A component (28) is for confining the removing element (24) and the supporting structure (26) in a juxtaposed relationship.

Abstract: An air filtration and purification system, particularly adapted for treating contaminated air within a preselected zone of a building interior space, includes a filter and purifier unit comprising first and second stage particle filters, an odor neutralizer comprising an ozone generator, an activated carbon adsorbent media for extracting gaseous compositions exposed to the ozone injected into the airflow stream and an ultrahigh efficiency final stage particle filter. All filter units and the ozone generator are disposed in a cabinet together with one or more air propulsion fans interposed between the second stage particle filter and the adsorbent media. The system is particularly configured for removing air containing tobacco smoke and other contaminants from smoking areas of restaurants and other places of business and may be configured to return purified and odorized air through ceiling ducts to form an air curtain defining the zone.

Abstract: A body furniture is provided having one or more air exhaust ports and a built-in air fan. A top plate having one or more air suction port is positioned on the furniture body, and a tornado-based suction unit is removably placed on the one or more of the air suction ports. The tornado-based suction unit includes a cylinder having a window formed through a peripheral wall thereof, and a suction hole formed through at least one of end surfaces of the cylinder connected to a suction side of the air fan. An artificial tornado is generated within the cylinder and collects contaminated air such as the smoke of cigarettes. The collected contaminated air is cleaned. Minus ions or fragrance may be supplied to air sucked from the suction hole to fill a space around the body.

Abstract: Apparatus for drying flowing gas includes a generally cylindrical vessel having a gas inlet and a gas outlet, two perforated plates of different metals in contact with each other transverse the interior of the vessel, and a third perforated plate downstream from the two mutually contacting plates.

Abstract: An integrated flue gas treatment condensing heat exchanger having a particle charger located upstream of the second stage heat exchanger of the system for improved cleaning of flue gas and increased removal of fine particulate matter.

Abstract: An integrated lamp air purification and cleansing system is disclosed which includes a lamp body which supports a lamp and contains an air purification system. The lamp body includes an air inlet for drawing in air and an air outlet for blowing out the air. An air purification system is enclosed in the lamp body for filtering and cleaning the air flow drawn in from the air inlet whereby the air flow blown out from the air outlet is filtered and purified. The air purification system includes an activated charcoal filter and an electrostatic filter for filtering particles from the air flow. The electrostatic filtering device further includes many elongated channels each surrounded by conductive channel walls which allow the air flow to pass through. Each of the elongated channels includes a discharging needle located in a center portion of the channel which induces an electrical discharge and ionization in the air flow passing through.

Abstract: Apparatus for drying flowing gas includes a generally cylindrical vessel having a gas inlet and a gas outlet, two perforated plates of different metals in contact with each other transverse the interior of the vessel, and a third perforated plate downstream from the two mutually contacting plates.

Abstract: An existing exhaust hood having a single coarse particulate filter for filtering contamination laden air is replaced by a filtration module preferably having two filters and optionally a third filter. The two preferred filters are a grease baffle filter and an electrostatic air cleaner (EAC). Optionally, a charcoal filter would be a third filter in a series of three filters for removing odors from exhausted air. The preexisting exhaust fan of the hood would be maintained in use and the preexisting duct work to the exterior of a building would also be maintained for exhausting the now filtered air to the exterior of the building. The filtration module would lower the amount of volatile organic compounds to an acceptable level so as to prevent pollution of the exterior environment of a building.

Abstract: An automatic air cleaner has a case and a base; wherein the case has a central cavity provided with a number of receiving grooves defined by ribs disposed at both inner lateral walls of the central cavity for a dust collecting plate and a filter plate to be inserted therein. Dirty air pumped into the case body is cleaned in sequence, moving from the dust collecting plate having rectangular dust collecting members cooperating with electric discharge rods, the filter plate made up of non-woven fabric and provided with an odoriferous agent, and then an ozone tube whose generation of ozone contributes to the termination of bacteria existing in the air. Finally anion pins are adapted to electrify the dust left over in the air so that when the fresh air blown out of the through slots of the case by fans driven by motors, the dust will drop onto the ground. In addition, the dust collecting plate, filter plate, and ozone tube can be easily replaced or withdrawn for cleaning in maintenance.

Abstract: A system incorporating an agglomerator is provided for removing fine particulates from a gas stream. The agglomerator (100) is coupled to a flue (12) for agglomerating fines (30) entrained in a gas stream, the agglomerates (40) reentrained into the gas stream are carried by ductwork (14) to an existing particulate removal system (20). Agglomerator (100) includes at least two screen electrodes (102, 104) for charging the particulates (30) and temporarily collecting the charged particles on the collection electrode screen (104). The charging electrode (102) is provided with a plurality of spaced pointed electrode elements (108), the spacing therebetween being proportional to a spacing between the two screen electrodes (102, 104). The screen electrodes (102, 104) have a grid spacing sufficiently large to insure reentrainment of the agglomerates (40) back into the bulk gas stream for separation by the existing particulate removal system (20).

Abstract: An electrostatically enhanced separator (EES) which provides mechanical separation and electrostatic separation to yield a compact and highly efficient separation system. The EES (10) may be incorporated in a collection system as well using a conventional collection device such as a cyclone collector (32), bag filter (37) or electrostatic precipitator (38). The EES (10) includes a cylindrical-walled separation chamber (11) with an inlet passage (13), a clean flow outlet (21), and a particle outlet passage (15). The inlet passage (13) and particle outlet passage (15) are both thin elongated slits which open tangentially to the cylindrical wall of the chamber for providing a substantially flush incoming flow path dispersed lengthwise along the wall.

Abstract: The suction hood has an air depollution apparatus that is associated therewith and includes, inside a container that is connected to an intake grille in a downward region and to a discharge grille in an upward region, a mechanical filter, an activated-charcoal filter, suction fans that are adapted to produce a flow of air, and a collection device. The collection device includes, in succession: an electrification grid, which is supplied at a high voltage with negative polarity and is arranged on a horizontal plane that lies transversely to the container; a partition, which is arranged at an angle in front of the electrification grid so as to convey the stream of air toward at least one region that has a narrower cross-section; a negatively-charged deflector plate and a positively-charged collector plate that are arranged vertically so as to face each other at a short distance, so as to delimit the respective above- mentioned region having a narrower cross-section.

Abstract: A self contained air movement system for air purification and infection control includes an elongated upright enclosed housing including a base module, sidewalls, and an upper module. A fan intermediate the base module and the upper module draws unclean air from a room containing the system through the base module, then discharges a purified air stream from the upper module. The base module includes a downward facing air intake opening spaced from the floor. A pair of pre-filters are disposed on the base module in stacked relationship for trapping relatively large particulate matter from the entering air stream. The upper module includes a discharge grille opening to the environment with angled louvers for guiding and re-directing the purified air stream from a downstream HEPA-type filter into an inclined stream, flowing proximate to and along the ceiling of the room in which the system is located.

Abstract: In an air purifying apparatus having a housing formed with a recess in which are fitted a static activated carbon panel and a high voltage dust collecting panel, the improvement wherein said high voltage dust collecting panel includes a plurality of cross bars and ventilation slits therebetween, said cross bars being coated with a high conductive and oxidation resistant alloy powder to form anodes and cathodes which are respectively connected to the positive pole and negative pole of a high voltage generating circuit.

Abstract: An exhaust gas cleaning device is provided, which is simple in structure and offers good performance in the cleaning of exhaust gas from car engines. The cleaning device includes a conductive cylindrical body through which the exhaust gas passes. A shaft is installed at the center of the conductive cylindrical body. A set of blades is provided on the shaft acting as a fan for sucking the exhaust gas in and out of the conductive cylindrical body. A scraping knife is provided also on the shaft. A static-electric generator having one pole connected to the cylindrical body and the other pole connected to the shaft is used to create an electric field between the cylindrical body and the shaft that ionizes smoke particles in the exhaust gas and deposits them on the inner wall of the cylindrical body. A collecting chamber is provided in communication with the inside of the cylindrical body for collecting deposition of smoke particles scraped by the scraping knife off the inner wall of the cylindrical body.

Abstract: The invention concerns a method and device for removing particles, in particular soot particles, from exhaust gases produced by internal-combustion engines. The invention calls for the particles to be electrostatically charged by an electrode (4). The particles or particle agglomerates are trapped by a fine-mesh metal filter (5). The conducting material (5a), preferably a sintered ferritic metal, of which the filter (5) is made can also be used as a collecting electrode. A high voltage (6) is applied (7, 10) to the electrodes. At intervals, preferably at regular intervals, an electric current is passed (11, 12) through the filter (5), causing the filter material (5a) to heat up to a temperature above the ignition temperature of the particles. The preferred shape of the filter surface is a cylinder, truncated cone and/or cone.

Abstract: This invention relates to an ion generator capable of being mounted on an air duct and injecting ions in the air stream inside the duct for enhancing the performance of a filter downstream. The unit consists of a high voltage generator, a connector for connecting such generator to a low voltage source, one or more ionizing needles, and a clamp for attaching the unit to an air duct.

Abstract: A contaminated air purifying apparatus capable of decreasing particles such as dust floating in air, soot produced by a combustion engine and the like and air pollutants such as nitrogen oxides (NOx) contained in exhaust gas. Particulates such as dust, soot and the like are electrostatically negatively charged and collected in a purifying filter section by coulombic force. NOx is converted into N.sub.2 and CO.sub.2 by an action of carbon fiber or carbon particles, resulting in decreased in concentration. The carbon fiber and carbon particles are preferably modified into an increased surface area of 200 to 2000 m.sup.2 /g.

Abstract: A small, battery-powered air purifier can be clipped to a wearer's front shirt pocket or worn suspended from a cord about the wearer's neck. The device includes a housing containing a compact circuit that transforms direct current provided by the battery into a negative high voltage pulsating current which is connected to a sharp metal point contained within a chamber inside the hollow housing. A corona discharge forms on the sharp point, ionizing air molecules and any particulates, and generating ozone. An opening into the chamber is covered by a noncorrosive metal grid connected to the positive terminal of the battery. The negative ions are attracted to this grid, thereby completing an electrical circuit. Movement of the ions to the grid results in mass movement of air which causes a stream of air to emerge through the grid. As the air passes the grid, negatively charged particulates are deposited on the grid.

Abstract: Disclosed is a filter for a reduced threat chemical/biological protective spiratory device which includes a housing having an air intake orifice and an air exit orifice and which encloses a filtering element which includes a plurality of bonded spherical carbon beads arranged in a open cell type matrix. The filtering element also includes an aerosol and particulate filtering element which is a plurality of electrostatically charged polypropylene fibers.

Abstract: A muffling and denitrating apparatus capable of lowering a level of noise generated by a combustion engine and reducing a concentration of NOx in exhaust gas of the engine. Sound-damping and denitration are accomplished by a carbon fiber or particle layer arranged in the apparatus. Exhaust sound is adsorbed by carbon fibers or carbon particles, resulting in a sound pressure thereof being reduced. NOx is converted into N.sub.2 and CO.sub.2, to thereby be decreased in concentration. Carbon fibers and/or carbon particles for the carbon fiber or particle layer are preferably treated or modified with nitrogen monoxide gas or a nitric acid solution, resulting in having an increased surface area as large as 80 to 2000 m.sup.2 /g.

Abstract: An electrostatic air cleaner is disclosed for use in removing particulate matter from moving streams of air. A high voltage ionizer is used as a corona source to ionize the particulate matter as it approaches the air filter portion of the electrostatic air cleaner. The air filter uses reticulated polyether foam filter media for collecting the particulate matter, and the filter media is non-deliquescent, thus preventing the high-voltage electric field from being dissipated by imbedded water vapor, which is the cause of filter inefficiency in the prior art. In one embodiment, the air filter uses strips of conductive material raised to a very high DC voltage interleaved between strips of conductive material held to ground potential, and these strips are oriented so as to be parallel to the direction of the air flow through the air filter's foam filter media, thereby creating an electric field that is perpendicular to the direction of air flow.

Abstract: An air filter material for intercepting dust is disclosed. The material is free of lubricants and antistatic agents, and consists of a blend of (I) polyolefin fibers and (II) polyacrylonitrile fibers that are geometrically stable. The fibers (I) are two-component polypropylene/polyethylene fibers of the core/jacket or side-by-side type, and fibers (II) are halogen-free. The fiber blend is washed during the manufacturing process after they are first combined.

Abstract: Disclosed is an apparatus for removing emissions, originated in the manufacturing industry, especially from polymerization operations and thermoplastic polymer processing operations which has a duct system for collecting the air, containing emissions, with an entrance and an exit, a first heat exchanger, which is connected to the entrance of the duct system, a liquid removal system which is connected to the first heat exchanger, a second heat exchanger, which is connected to the liquid removal system and a fan which is connected to the second heat exchanger and the exit of the duct system.

Abstract: Disclosed is an apparatus for removing emissions, originated in the manufacturing industry, especially from polymerization operations and thermoplastic polymer processing operations which has a plurality of ducts, an entrance for collecting air, containing the emissions and an exit for exiting exhaust air, a first heat exchanger which has a hot side with an entrance and an exit and a cold side with an entrance and an exit, a second heat exchanger, which has a hot side with an entrance and an exit and a cold side, a liquid removal system, and a fan, whereby the first heat exchanger is connected with the entrance of the hot side to the entrance of the duct system and with the exit of the hot side to the entrance of the hot side of the second heat exchanger by a duct; the exit of the hot side of the second heat exchanger is connected to the entrance of the cool side of the first heat exchanger by a duct; the precipitator is connected to the exit of the cool side of the first heat exchanger by a duct and to the f

Abstract: Portable vacuum and air filtration units including a plurality of separately transportable modules are disclosed. Some units include a mechanism for locking the modules together during use, an air inlet located in one of the modules, a debris screen and a mechanism for receiving debris stopped by the screen located in one of the modules, an electrostatic filter located in one of the modules, a bag filter assembly located in one of the modules, a HEPA filter assembly located in one of the modules, and a mechanism for drawing a substantial volume of air through the inlet, screen, electrostatic filter, bag filter assembly and HEPA filter assembly. Other units include a pliable, tubular mesh for filtering debris.

Abstract: In the process for investigating particles situated in a gas, a gas stream is guided past a miniaturized UV excimer radiator. In this case, the particles are ionized and subsequently filtered out, and the resultant photoelectrically induced current is measured. Since particles from different sources (petrol engine, diesel engine, cigarette smoke) exhibit a wavelength dependence which is characteristic of the source, by measurements at at least two wavelengths, which is readily possible when using UV excimer radiators with different gas fillings, pollutants can be detected according to the source.

Abstract: An integrated SCR ESP employs catalytic collector plates for NO.sub.x and particulate removal. Ammonia injected either directly in the ESP or upstream therefrom catalytically reduces NO.sub.x to nitrogen and water. The excess ammonia assists in capturing particulates in the ESP. This prevents problems of ammonia slippage. The SCR catalytic collector plates are positioned in at least one field of the ESP and preferably in at least the first field.

Abstract: A composite filter media is formed of a plurality of layers. A central layer of electrostatically charged material formed of a carded mixture of polyolefin fibers such as polypropylene and electro-negative substituted organic resin fibers such as modacrylic acrylonitrile-vinyl, chloridevinylidene chloride copolymer efficiently filter more than 99% of 0.1 to 0.5 micron particles. A flame retardant prefilter layer of polyester removes large particles and a backing of flame retardant linear polyester provides tear resistance. An optional layer of electrostatically charged, melt blown, polyolefin such as polypropylene prevents the central layer from loading up by effectively filtering intermediate sized particles.

Abstract: A vacuum cleaner system includes a vacuum cleaner having a hollow air inlet, an air outlet, a removable dirt bag communicating with the inlet and the outlet, and means for moving initially dirt-laden air from the inlet to the outlet via the bag. The system also includes a charge generator for generating an electrostatic charge of a given polarity on the bag. The system optionally includes a charge generator for generating an electrostatic charge of the given polarity on the initially dirt-laden air.

Abstract: An adjustable air filter for use in heating, ventilating, cooling, and forced air systems. The air filter includes a media for filtering air and adapted to be cut with scissors, and a frame embracing the peripheral edges of the media. The frame includes a pair of male sections and a pair of female sections respectively telescopingly receiving the male sections. Also, the frame is adapted to be cut with scissors and is preferably formed of polyvinyl chloride. Each of the male sections includes a T-shaped projection and each of the female sections includes a complementary shaped T-shaped slot adapted to telescopingly receive the T-shaped projection for preventing inward separation of the sections from one another. In the preferred form the media is of the electrostatic type and includes at least one layer of polypropylene woven in an egg-crate pattern. Also, the layer preferably includes a pad of washable polyester material.