Abstract: The invention refers to a composite filter for filtering a stream of ambient air including at least one non-prebonded upstream tier and one non-prebonded downstream tier, wherein the ratio of absolute pore volume of upstream tier to downstream tier RAPV>2, and the absolute projected fiber coverage of upstream tier and of downstream tier APFC>95%. Further, the invention refers to a method of making such a composite filter including the steps of (a) laying down a filtration material onto a support to form the upstream non-prebonded tier, (b) depositing onto the upstream tier the downstream non-prebonded tier, and (c) bonding the tiers to form a composite filter having a unitary stratified structure.

Abstract: A multiple-field precipitator, flue-gas treating device, in accordance with the principles of the invention, includes a first section having a dual-function, sensible-cooling heat exchanger/electrostatic precipitator, a second section having a wet electrostatic precipitator, and a middle section fluidly connecting the first and second sections. In the first section, the exchanger/precipitator sensibly cools the flue gas and collects most of the dust from the flue gas. In the middle section, the dust-reduced flue gas is combined with an alkaline material, thereby forming reaction products. These reaction products and several other pollutants are captured by the wet electrostatic precipitator, in the form of a pollutant-laden liquid. The pollutant-laden liquid is directed to a series of heat exchangers and settling tanks, where various pollutants such as SOx, metals, NOx, and chlorides are removed in different stages.

Abstract: An air purification and disinfection apparatus incorporates an air inlet filter (1) spanning the intake of the apparatus, an ultraviolet light source (2) for treating the air within a chamber (14) of the apparatus, and an equalising screen (3) spanning the outlet of the apparatus. The chamber (14) is lined with a reflective sheet (11) or coating such that the ultraviolet light is reflected around the chamber (14). The air inlet filter (1) removes larger airborne particles from the airflow prior to entering the chamber (14). The light source (2) may be located in the chamber (14) or in a housing (16) which communicates with the chamber (14). With the reflective surface of the chamber (14), the intensity of the light source (2) can be maintained when dirt begins to build up on the light source (2), thereby extending the length of time that passes between each cleaning of the light source (2).

Abstract: The invention describes a multi-layer filter structure and the use of a multi-layer filter structure for the dust removal from gases, wherein a coarse dust filter layer, a fine dust filter layer, and a support layer are disposed behind one another in the direction from the inflow side to the outflow side, and which is designed such that the fiber diameter distribution within the coarse dust filter layer and fine dust filter layer has a gradient, and that the fiber diameters of the coarse dust filter layer and fine dust filter layer continually decrease from the inflow side to the outflow side. This multi-layer filter structure may be used in a filter cassette for industrial dust removal, as well as in a stationary or mobile home dust cleaning device.

Abstract: A bow-reduced precipitator collector plate assembly and an appertaining method include a precipitator collector plate that contacts a spring-like stiffening element configured to be attached to a fixed anchor or an adjacent anchoring collector plate. The stiffening element is configured to apply a force in a direction normal to a primary plane, which is generally co-linear but opposite in direction of a direction of bowing, of the precipitator collecting plate.

Abstract: The invention relates to a method for the concentration of the spent acid produced in connection with the scrubbing smelter or roaster gas. The hot gas produced is scrubbed first by dry and then by wet separation, and the scrubbed gas is conducted to the manufacture of a sulfurous end product. The spent acid formed is dilute, and its sulfuric acid content is increased by making use of the thermal capacity of the actual hot gas, which comes from dry separation. Thus, by making use of the thermal capacity of the gas created in the process, it is possible to replace, at least partly, the use of evaporators.

Abstract: An improved method for charging ultrafine particles in coronas (e.g., unipolar or bipolar corona discharges) by exposing the particles to X-ray irradiation. Experimental tests have verified that positive corona in the presence of X-ray irradiation results in maximum or optimum charging efficiency, followed by a negative corona in the presence of X-ray irradiation, X-ray radiation only (without corona), negative corona only (without X-ray irradiation), and finally positive corona only (without X-ray irradiation). This method and system is particularly well suited for use with bioaerosol particles wherein exposure to the corona discharge and X-ray irradiation serves to both capture and inactivate the bioaerosol particles using a single device.

Abstract: A lighting equipment for purifying air, includes an anion generator generating anions to purify air; a housing including an electric power source supplying an electric power, an amplifier amplifying the electric power from the electric power source, and an emitting aperture member having a plurality of holes for exhausting the generated anions therethrough; and at least one illumination unit engaged with the housing.

Abstract: A local cleaning system which uses a charged air shower unit for forming a shield curtain by means of an ion wind, and a local exhaust device for exhausting the air containing dirt and dust settled down on the floor by the ion wind to construct a clean shielded space with no need for a dedicated partition wall. With this local cleaning system, the charged air shower unit provides negative charges for gas molecules, and dirt and dust, floating microorganisms, odor constituents, and other foreign matters, for electrically neutralizing them, and leads the gas molecules and foreign matters which have lost the charges and which Brownian motion is suppressed, by means of the ion wind for effectively sucking them into the local exhaust device or air cleaner. Because a charged air curtain comprising an invisible ion wind provides a shield plane, a clean shielded space can be constructed with no need for a dedicated partition wall.

Abstract: A method and apparatus for removing contaminants from gas streams. A first step involves selecting a contaminant to be removed from a gas stream and determining a characteristic ionizing energy value required to selectively ionize the selected contaminant with minimal effect on other contaminants in the gas stream. A second step involves applying the characteristic ionizing energy value to the gas stream and selectively ionizing the selected contaminant. A third step involves capturing the selected contaminant after ionization.

Abstract: An air purifier has a simply manufactured and assembled ionizer, which increases the charging efficiency for dust particles through maximally increased discharge spaces and prevents electrical accidents. The air purifier includes an ionizer and a collector. The ionizer includes two ground electrode units and at least one discharge electrode, the two ground electrode units each having one or more electrodes, each formed in a hollow semi-cylindrical shape, the two ground electrode units being joined to face each other, the at least one discharge electrode being placed in spaces formed between the hollow semi-cylindrically shaped electrodes of the joined ground electrode units, thus charging dust particles passing through the spaces between the hollow semi-cylindrically shaped electrodes. The collector is electrically charged with a polarity opposite to a polarity of the charged dust particles.

Abstract: A method is for selectively removing gaseous pollutants from the ambient air, and a device is for implementing the method. Undesirable emissions may be selectively and completely removed from the ambient air using relatively simple equipment and a small amount of energy. Pollutants contained in the air to be purified are ionized by the action of optical radiation, based on resonant and/or non-resonant single-photon excitation and/or multiple-photon excitation, so that the ionized pollutants are drawn off and removed from the air to be purified, using an electric field. A small portion of the energy necessary for the ionization may also be applied in the form of microwave energy or electric-field energy. The method and device may be used in air-conditioning or other air-circulation systems.

Abstract: This disclosure relates to a method for deaerating a liquid layer such as a coating solution using electrostatic forces. A flow of charged particles is created above and moved towards a low conductivity liquid layer. The flow of charged particles causes localized thinning of the liquid layer which facilitates the removal of bubbles of entrained gas from the liquid by bringing those bubbles closer to the exposed surface of the liquid and rupturing them at that surface. This electrostatic deaeration technique is combined with other non-electrostatic liquid layer thinning techniques or degassing techniques to further facilitate removal of bubbles from the liquid in preparation of further processing of the liquid. The liquid layer may be stationary or flowing with respect to the application of charge particles.

Abstract: An electret is described that includes a surface modified polymeric article having surface fluorination produced by fluorinating the polymeric article.

Abstract: A dust filter bag having a highly porous backing material ply and a method for producing the dust filter bag. The dust filter bag includes at least one filter material ply and at least one backing material ply, the backing material ply possessing an air permeability of at least 900 l/m2 x s, a burst strength of at least 70 kPa, a rupture strength longitudinally better than 10 and transversely better than 3 N, a flexural rigidity longitudinally better than 0.5 cN cm2 and transversely better than 0.25 cN cm2, a basis weight of 30-80 g/m2 and a droplet sink-in time of less than 10 minimum. The dust filter bag can be produced by the following steps: mixing fibers including cellulose fibers and fusible fibers into a homogenous fiber mix, processing the fiber mix into a fiber web by wet laying, drying the fiber web, curing the dried fiber web by thermofusion into a backing material ply, processing the backing material ply with a filter material ply into a raw bag, and finishing the raw bag into a dust filter bag.

Abstract: An electrical type grid electrostatic collector/separator removes particles from an air stream. The apparatus includes multiple parallel grids that act as the porous material, enclosed in a sealed compartment so that the entrained air flows parallel and between one or more centrally located grids. A direct current high voltage field is established between the grids with the polarities alternating between facing grids. The system is preferably used for conductive and semi-conductive materials because of the ease at which the particles can receive an induced charge. The charged particles are separated and collected when they are attracted toward the relatively open wire or woven grids and pass laterally through and onto the next attracting grid until they are out of the air stream and generally fall by gravity to the collection vessel. When non-conductive particles are present, external methods of pre-charging by corona discharge are preferably used.

Abstract: Particles in a fluid flow are concentrated by a combination of electrical charging and focussing and passage through a virtual impact concentrator. The fluid is passed through an electrical charging section and an electrical focussing section and then to a virtual impact concentrator. The majority of charged particles in a selected size range are collected through a minor discharge passage extending axially from the virtual impact concentrator. The invention is particularly suitable for sampling engine exhaust gases and ambient aerosols.

Abstract: Elemental mercury is removed from emissions of coal-fired utilities by the selective photoionization of mercury atoms using ultraviolet light, followed by electrostatic precipitation of the mercury ions. Mercury is first exposed to light of a wavelength which boosts the mercury to an excited state. Then mercury is ionized using light of a different wavelength. The ionized mercury atoms are exposed to supersaturated water vapor to produce charged droplets which are precipitated, such that the exhaust effluent is substantially devoid of mercury or the mercury level is substantially reduced.

Abstract: A fiber spinning device and process for manufacturing a web of fibers including a homogeneous mixture of fibers of different characteristics. Monocomponent fibers of different polymers can be extruded side-by-side from the same die system. Sheath/core bicomponent fibers can be alternated with monocomponent fibers formed of the same core polymer as used in the bicomponent fibers. Bicomponent fibers having a common core polymer and different sheath polymers can be extruded from alternate spinneret orifices in the same die plate. Multiple distribution plates are provided with surface grooves or depressions to direct polymer materials from independent sources to only selected spinneret openings in an array of spinneret openings while maintaining the polymers segregated from each other.

Abstract: A vehicle brake assembly includes a brake rubbing interface operative to slow a vehicle when activated. The interface produces airborne brake dust particles when activated. A dust collector plate is positioned in close proximity to the brake rubbing interface to collect the brake dust. A charging circuit is operative to generate an electrostatic charge so that the brake dust is attracted to the charged collector plate.

Abstract: Elemental mercury is removed from emissions of coal-fired utilities by the selective photoionization of mercury atoms using ultraviolet light, followed by electrostatic precipitation of the mercury ions. Mercury is first exposed to light of a wavelength which boosts the mercury to an excited state. Then mercury is ionized using light of a different wavelength. The ionized mercury atoms are exposed to supersaturated water vapor to produce charged droplets which are precipitated, such that the exhaust effluent is substantially devoid of mercury or the mercury level is substantially reduced.

Abstract: The invention relates to a method to clean air for separating materials in the form of particles and/or droplets from a gas flow. The gas flow is directed through a collection in which the outer walls are grounded, and in which high voltage is supplied to the ion yield tips arranged in the collection chamber. Thus an ion beam from the ion yield tips towards collection surfaces is established to separate desired material from the gas flow. The electrically conductive collection surfaces are electrically insulated from the outer castings and high voltage is supplied to the collecting surfaces, in which the direct-current voltage has an opposite sign as the high voltage directed to the ion yield tips. The collection surface is totally conveniently and rapidly detached for clean material replacement.

Abstract: A method is for selectively removing gaseous pollutants from the ambient air, and a device is for implementing the method. Undesirable emissions may be selectively and completely removed from the ambient air using relatively simple equipment and a small amount of energy. Pollutants contained in the air to be purified are ionized by the action of optical radiation, based on resonant and/or non-resonant single-photon excitation and/or multiple-photon excitation, so that the ionized pollutants are drawn off and removed from the air to be purified, using an electric field. A small portion of the energy necessary for the ionization may also be applied in the form of microwave energy or electric-field energy. The method and device may be used in air-conditioning or other air-circulation systems.

Abstract: There is provided a heavy oil fired boiler exhaust gas treatment apparatus which removes soot and dust and SO3 in the heavy oil fired boiler exhaust gas efficiently at a low cost without using an excessively large apparatus. The treatment apparatus comprises a charging device 3 provided at the inlet of an absorption tower of a wet type exhaust gas desulfurizer 4 and neutralizer pouring means A provided on the upstream side of the charging device 3 to pour a neutralizer into exhaust gas and neutralize SO3 in the exhaust gas.

Abstract: A filter system with a housing defining a passage between an inlet and an outlet and one or more structures located in the passage in the housing. Each of the structures comprises two or more layers of insulating materials with an imbedded fixed charge located at at least one of the interfaces between the two or more layers. At least one of the structures has an imbedded fixed charge at a charge level of at least 1×1012 charges per cm2.

Abstract: The present invention relates to a pleated filter made of a multi-layer filter medium, including at least one filter paper layer having area weights of 30-100 g/m2, a microfiber nonwoven fabric layer having area weights 5-120 g/m2 and a support nonwoven fabric layer made of synthetic, polymeric fibers having area weights of 10-120 g/m2. The layers of the pleated filter contain fused polymer areas by which the fabric layers are bonded to the paper layer, and by which the fabric layers are made firmer within themselves. When subject to a fractional efficiency test at an initial pressure difference of at most 180 Pa, at a boundary speed of approximately 2.62 m/s and a flow speed through the filter medium of approximately 0.13 m/s, the pleated filter is able to separate at least 90% of particles greater than 0.3 &mgr;m, at least 92% of particles greater than 0.

Abstract: Ionizing apparatus includes a housing that supports a plurality of ionizing electrodes disposed within fluid apertures that are connected via tubing conduits to pass fluid therethrough about the electrodes. Gas to be ionized supplied under pressure to the apertures transports gas ions generated at the electrodes in response to high ionizing voltage supplied thereto. To clean the ionizing apparatus, cleaning liquid is supplied under pressure in one flow direction through the tubing conduits and apertures to remove particles from within the tubing conduits and apertures and from surfaces of the electrodes.

Abstract: An dry horizontal flow electrostatic precipitator wherein a portion of the gas flow passing through the precipitator is extracted from the upper portion of the casing, such extraction flow having a lower particle concentration than gas flow at the bottom portion of the casing due to re-entrainment. The extraction gas flow is extracted by a manifold positioned at the top of the casing.

Abstract: This machine introduces microwaves as an alternate means of of disinfection, filtration, purification, and sterilization of air, liquids, and solids or any combination thereof that are microwave compatible materials. It is more effective than any other methods used in the past.

Abstract: The invention relates to a process and to a device for eliminating the harmful volatile elements, in particular chlorides and/or sulfates, contained in a stream of particle-laden fumes, in which a given fraction of at least 5% of said fumes, referred to as ‘by-passed fumes’, is extracted, the harmful elements of the by-passed fumes are caused to condense, at least with regard to their particles, according to a distribution that is a function of said fraction extracted, and said particles are filtered to isolate said harmful elements. According to the invention, at the time of filtering, said particles are separated into at least two fractions, one with a fine grain size and the other with a coarse grain size, using a separation selectivity adapted to said distribution of the elements in order for said coarse grain size faction to be poor in harmful elements and for said fine grain size fraction to be rich in harmful elements.

Abstract: A method for filtering a dirty air stream in a vacuum cleaner to obtain a clean air stream comprises subjecting the dirty air stream to a first cyclonic separation stage to obtain a partially cleaned air stream and subjecting the partially cleaned air stream to an electronic filtration stage and optionally a second cyclonic separation stage to obtain the clean air stream. The electronic filtration stage is optionally removable with a cyclonic cleaning stage from the vacuum cleaner. The electronic filtration stage is optionally an electrostatic precipitator which utilizes air flow through the vacuum cleaner to generate the voltage used by the electrostatic precipitator.

Abstract: An electret is described that includes a surface modified polymeric article having surface fluorination produced by fluorinating the polymeric article.

Abstract: A method for protecting an exposed surface in an enclosed space, such as a building, medical room, manufacturing space or consultation room, from harmful airborne agents. Airborne agents are charged by exposure to an electrostatically-charged cloud and an electrostatically-charged field is created for electrostatically manipulating the harmful airborne agent away from or toward the exposed surface for protecting the exposed surface from the harmful airborne agent. The harmful airborne agent may be collected on a charged surface, and destroyed by ultraviolet light.

Abstract: The present invention relates to a method for cleaning of a gaseous fluid from particles being present in the fluid, the gaseous fluid being ionized, i.e. the particles are subjected to a charging, and that the ionized gaseous fluid is brought to pass through a precipitator unit (2) including a filter medium. The invention also relates to a device for cleaning of a gaseous fluid. Filters for cleaning of air often require expensive filter medium and complicated arrangements as regards ionization of the air and charging of the filter medium. The present invention is characterized by an extremely simple method where the air is ionized and then the ionized air is brought to pass through a filter medium of polypropylene.

Abstract: A novel air filter design for use in residential and commercial heating and air conditioning systems comprising a laminated unit having a filter media where the upstream side of the filter media having a porous layer of passive electrostatic netting. The air filter design has a corrugation configuration to increase the available surface area when compared to conventional flat filters.

Abstract: A dual- or multi-layer filter medium for air filtration, having at least one meltblown layer (2, 2a and 5) at least one meltblown layer (2 and 2a) is placed on the inlet side of the filter medium. The meltblown layer has a pore size larger than that of the next following layer or layers.

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: Novel electret articles containing a polymer and a performance-enhancing additive can be identified by their thermally stimulated conductivity characteristics or their filtration properties. Electret articles such as nonwoven filter webs and respirators exhibit superior oily mist loading performance, low penetration and a small pressure drop.

Abstract: A liquid decontamination system has a liquid treatment chamber having a liquid input and output and a gas input and output. A plurality of electrodes are positioned to place a voltage across the liquid treatment chamber and the liquid therein. A plurality of magnets are also positioned adjacent the electrodes for placing a magnetic field across the chamber and liquid therein. As the contaminated liquid is fed through the liquid treatment chamber, a predetermined gas, such as nitrogen, ozone, oxygen, or hydrogen peroxide, are fed into the contaminated liquid while simultaneously having the electric and magnetic fields applied to the liquid. The liquid leaving the treatment chamber is fed to a flush tank which removes contaminates and agglomerated solids therefrom.

Abstract: A vacuum filter bag is constructed of layers which include a high air permeability multipurpose layer positioned upstream in the direction of air flow of a second filtration layer. The second filtration layer can be a wet-laid filter paper, a dry-laid filter paper or a spunbond nonwoven. The multipurpose layer can be made of high bulk meltblown nonwoven, dry-laid or wet-laid high dust holding capacity paper spunblown modular or microdenier spunbond. The high dust capacity papers are characterized by greater thickness and higher air permeability than is normally used in traditional filter layers of vacuum cleaner bag structures. These characteristics allow the high capacity papers to filter large dirt particles and to capture within their pores large amounts of dust particles. This protects the downstream second filtration layer from shock loading and enables the composite structure to pass air at high rate at low pressure differential for much longer than conventional vacuum cleaner bags.

Abstract: A disposable vacuum cleaner filter bag is constructed of layers which include a filtration grade meltblown fleece layer having a basis weight of about 10-50 g/m2 and air permeability of about 100-1000 L/(m2×s) and a coarse filter layer in which the coarse filter layer is placed upstream of the filtration grade meltblown fleece layer. The coarse filter layer can include either wet-laid high dust capacity paper, dry-laid high dust capacity paper, high bulk meltblown nonwoven, Spunblown (Modular) nonwoven or microdenier spunbond nonwoven. Juxtaposition of the layers causes the coarse filter layer to capture large dirt particles and permits the filtration grade meltblown fleece layer to capture much of the remaining dust particles. The novel bag exhibits high air permeability and low pressure drop at high dust loading. A method of filtering gas through such a filter is also disclosed.

Abstract: A dust reduction system for reducing airborne contaminants such as, for example, dust, smoke, microorganisms, etc., includes at least one ion generator made up of at least one ionizer bar and a ground plane which is parallel and proximate to at least one bar. The system can also include a dust collection device such as a tray containing an aqueous composition optionally containing a degreaser, and/or a metal sheet with a water rinse system, and/or the surfaces of a room-sized enclosed space. The system can be applied to any enclosed space where it is desired to obtain high efficiency reduction of airborne dust and microorganisms. The system is especially useful in poultry production and processing areas such as hatching cabinets, throwing rooms, and controlled environment poultry rearing rooms.

Abstract: A method of separating liquid drops from a gas stream includes the step of introducing the gas stream having a temperature greater than 600.degree. C. into shaped elements having very narrow channels through which the gas stream flows, wherein the shaped elements are of a material that becomes conductive at high temperatures and further includes the step of selecting the width of the narrow channels based on the gas stream velocity such that turbulence is generated along the flow path causing the liquid drops to strike the channel walls and deposit thereon. The apparatus for separating liquid drops from a gas stream includes a plurality of shaped elements having very narrow channels through which the gas stream having a temperature greater than 600.degree. C.

Abstract: An air filter for use in residential and commercial heating and air conditioning systems including a laminated unit (100) having a filter media (102) where either side of the filter media (102) has a porous layer (104, 106) of passive electrostatic netting. The air filter has a corrugation configuration (142, 144) to increase the available surface area when compared to conventional flat filters.

Abstract: An apparatus (10) to carry out a process for the in situ generation of agglomerate structures and the controlled influencing of the resulting agglomerates contains a closed flow duct (12) through which is directed an aerosol containing particles (14). For the purpose of the bipolar charging of the aerosol, at least one electrode pair (20, 22) is arranged in the flow duct (12), the electrode (20) being wired, so as to be ungrounded, to the negative pole of a current source, the strength of which is sufficient to produce a corona discharge between the electrodes (20 and 22). The electrodes (20 and 22) of each electrode pair are designed to be needle-shaped and are arranged to be insulated with respect to the flow duct walls, such that their tips (26) are disposed opposite each other.

Abstract: A method for affecting liquid droplets in a gas stream includes the steps of flowing a gas stream containing liquid droplets through a housing and positioning at least one surface in the housing, wherein the surface generates an electrical charge at high temperatures. The corresponding apparatus is characterized by a at least one surface generating an electrical charge at high temperatures.

Abstract: A collection device for collecting, under electrical control, particles (10) in an exhaust from a diesel engine is disclosed. The device has a needle electrode (8) having a needle tip (8a) for charging up the particles (10) by creating a corona discharge around the needle tip (8a) collecting electrode (11) for collecting the charged particles (10a) by electrostatic force and a high voltage power source (13) for applying prescribed high voltage between the needle electrode (8) and the collecting electrode (11), the high voltage power source (13) electrically being connected with the needle electrode (8) and the collecting electrode (11).

Abstract: A process for the scrubbing of undesirable substances from an exhaust gas stream which comprises passing the stream through a hollow cathode.

Abstract: A triboelectrostatic separation apparatus includes a mixing chamber having opposed first and second charging ports, a separator having a separation chamber, first and second electrodes, and a variable voltage source for applying respective positive and negative voltage potentials to the electrodes. First and second particle streams are delivered through the first and second charging ports resulting in the impingement of the particle streams upon each other within the mixing chamber, thus enhancing the electrostatic charging of the particles contained within the particle streams. The apparatus may also include a pre-separator having a pre-separation chamber, a charged particle collection chamber and a plurality of feed passageways providing fluid communication between the pre-separation and the charged particle collection chambers.

Abstract: A process is provided for conditioning fly-ash present in flue gas which also contains sulfur dioxide and steam by subjecting the fly-ash containing flue gas to ultraviolet radiation so as to convert steam present in the flue gas into hydroxyl radicals which oxidizes about 5 to 10 percent of the sulfur dioxide in the flue gas into sulfur trioxide. This photo-produced sulfur trioxide conditions the fly-ash and renders it more easily separated in the electrostatic precipitator.