Abstract: A method for filtering particle-laden gas includes electrostatically precipitating particles from the particle-laden gas to produce a gas having residual particulates, agglomerating the residual particulates, and using a fabric filter to filter the agglomerated residual particulates from the gas.

Abstract: A flue gas treatment system for a fossil-burning power plant having a fuel source and a boiler includes a barrier filter downstream of the boiler, the barrier filter including an electrostatically-stimulated fabric filter utilizing high-permeability fabric, having an air permeability of at least 75 acfm/sq.ft. A method of treating flue gas includes generating a flue gas; and passing substantially 100% of the flue gas from a boiler directly through an electrostatically-stimulated fabric filter incorporating high-permeability fabric with an air permeability of at least 75 acfm/sq.ft.

Abstract: An ionizing particulate scrubber is provided for the removal of particulate from a gaseous exhaust stream, said scrubber including two sections: a charging section and a collection section. The charging or ionizing section includes one or more cylindrical tubular ground chambers each with a rigid threaded rod electrode extending through the center thereof. A transformer/rectifier (T/R) is provided to supply high voltage DC power to the electrode such that the cylindrical tubular ground chambers act as the ground to enable a corona to form on the threaded rod electrode. As the gas stream passes through the current flowing from the electrode to the cylindrical tubular ground chambers walls, the particulate contained within the stream is electrostatically charged. The collection system includes either a fixed or fluid bed packed section which is constantly irrigated from above. Ground rods in the packing and liquid sump allow the entire section to act as a grounded collector for the charged particulate.

Abstract: A spot ventilator and method for spot ventilating a localized environment of a building is provided. The spot ventilator includes a passage and at least one corona discharge apparatus. The passage extending between an inlet positioned in the localized environment and an outlet. The at least one corona discharge apparatus positioned in relation to the passage such that a fluid from the localized environment is drawn into the passage through the inlet and is expelled through the outlet. The method of ventilating a localized environment of a building includes the steps of sensing a first change in the localized environment, energizing a corona discharge apparatus to produce an electric wind, drawing air from the localized environment into a passage via the electric wind and expelling the air from the passage through the outlet.

Abstract: A ventilation system for a building is provided. The ventilation system includes a pair of passages between the interior and exterior of the building and at least one corona discharge apparatus for drawing fluid through the passages. The ventilation system may also include an energy recovery ventilator for transferring energy, humidity or the combination of energy and humidity between the fluid flowing through the two passages. Variable flow rates through the passages are provided by varying the voltage to the corona discharge apparatus. In addition, the corona discharge apparatuses may filter the air flowing through the passages.

Abstract: Disclosed is a filtration enhancement apparatus and an associated method. The apparatus includes a number of electromagnetic grids that are placed in series. The first grid conditions ambient particles to generate particles with both a positive and a negative charge. These charged particles are then delivered to a second and third grid wherein a low, medium, and/or high frequency alternating current is employed to force the positive and negative charged particles to collide and conglomerate with one another. The conglomerated particles are then sent into the ambient environment for subsequent filtration.

Abstract: Contaminant laden gas streams from wood product dryer operations, and other sources, are purified. The gas stream first is saturated with moisture by contacting the gas stream with fine liquid droplets which entrain particulates. The gas stream then is subjected to a plurality of separate particulate and liquid droplet removal steps before a droplet-free gas stream having substantially reduced particulate contaminant levels is passed to a burner for removal of volatile organic compounds from the gas stream.

Abstract: The invention provides an apparatus for removing airborne pathogens and toxic substances from a surface of an article or a volume of air, comprising: a main processing chamber having a door for ingress to and egress from the main processing chamber, at least two high voltage electrodes for generating a current. The electrode can form ozone, if desired, to destroy pathogens. Optionally, the electrodes can be in a sealed or unsealed glass tube, with or without mercury, to generate ultraviolet light for photochemical reaction with pathogens or other contaminants. The apparatus also includes a post processing chamber comprising at least one filter for removing or absorbing airborne particulates and pathogens, and includes low voltage electrodes to neutralize charges in air transmitted from the main processing chamber.

Abstract: A method of removing mercury from a coal fired power plant exhaust gas includes passing the exhaust gas through a bulk particle filter to remove coarse particles, introducing powdered activated carbon into the exhaust gas downstream of the bulk particle filter, introducing mercury laden powdered activated carbon containing exhaust gas into a fine particle filter to separate the mercury containing powdered activated carbon from the exhaust gas, separating the powdered activated carbon from the mercury at an elevated temperature in an inert gas environment and recirculating the separating powdered activated carbon into the exhaust gas upstream from the fine particle filter. The desorption is preferably effected at a temperature of about 300 to 500° C. for about 5 to 60 minutes. The method is adapted to remove mercury which may be on the order of about 1 to 1000 ppm to 1 to 10 micrograms/cubic meter of exhaust gas. Corresponding apparatus is provided.

Abstract: The present invention provides a combination filter for filtering fluids comprising a flow channel particulate filtration media having a first face and a second face and a gas adsorbing filtration media. The flow channel particulate filtration media comprises a plurality of flow channels directed in flow direction and defined by inner surfaces. The flow channels having inlet openings through the first face and outlet openings through the second face of the flow channel particulate filtration media. The inner surfaces of said flow channels at least in part are provided with structures protruding therefrom and forming or extending into the flow channels or an electrical charge or a combination of both. The said gas adsorbing filtration media comprises a pad having a first face and a second face and width and length dimensions orthogonal with respect to each other and each individually to the flow direction and having a thickness dimension in flow direction.

Abstract: An air purifier includes a main body defining an air passage therein to allow sucked air to pass therethrough prior to being discharged, and a first filter installed in the main body to be switched between a closed state and an open state. The first filter removes contaminants from the sucked air in the closed state, and allows the sucked air to pass through the air passage in the open state. The air purifier may include a main body to suck and discharge air, with a bypass passage formed in the main body so that the bypass passage is opened or closed by a door, and a first filter installed in the main body. The sucked air passes through the first filter prior to being discharged when the door is closed, and passes through the bypass passage prior to being discharged when the door is opened.

Abstract: The invention relates to a dust filter, with at least one dust filter sleeve (1), closed at the bottom end thereof, impinged on from the outside by the dust-containing gases, including at least one electrofilter (3), with at least one collecting electrode (4). According to the invention, the filter effect may be improved, by means of increasing the degree of dust separation, whereby the at least one emission electrode (2) is arranged behind the at least one collecting electrode (4), as viewed from the filter sleeve (1). The filter sleeve (1) and associated support cages (7) are preferably electrically isolated. During cleaning of the filter sleeves (1) the ionised dust particles (5) fall for the greater part on the directly adjacent collecting electrode (4).

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: Apparatus and method for utilizing recirculated exhaust gas in semiconductor manufacturing system, in a manner substantially reducing the effluent burden on the exhaust treatment system and infrastructure of the semiconductor process facility.

Abstract: In an apparatus for the purification of a gas which apparatus comprises three-conduit section, that is,

Abstract: An improved method is disclosed for cleaning a flow of gaseous fluid, such as room air, from particles present in the fluid, the gaseous fluid being ionized, and using a conductive grid placed across and upstream of the filter for protecting the filter from being charged by free ions. An air purifier filter cartridge using the ion-intercepting grid of the invention is also disclosed. The grid may be connected to or electrically insulated from the ionizer ground potential, with equal effect.

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: A sintered stainless steel filter is used as the grounded electrode of a point-to-plane electrostatic precipitator. Particles flow through, rather than parallel to, the collection plate. Particle collection efficiency is empirically shown to increase as the charged particles are drawn closer to the grounded filter. The utilization of stainless steel fiber filter provides (1) low particle penetration (high particle collection efficiency) of different particle range, (2) applicability to all different particulate components, (3) high loading capacity but low pressure drop (less energy and maintenance needed), (5) low electric voltage for operating the system, and (6) low cost and small dimension.

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 the rows of filter elements are rows of high voltage discharge electrodes. Between the rows of discharge electrodes and the rows of filter elements are grounded perforated plates for creating electrostatic precipitation zones.

Abstract: A photochemical process for removing or minimizing the concentration of PCDD or PCDF compounds within an industrial gas stream. The process includes the direct photolysis of PCDD or PCDF compounds. Light within a particular spectral range is irradiated into the gas stream and is absorbed by the PCDD and PCDF compounds in the presence of a hydrogen donor and this results in producing a lower chlorinated PCDD or PCDF compound form. In addition, the gas stream may be treated by removing particular matter therefrom and thereafter subjected to the above-described irradiation. Further, as another optional step, the gas stream may be irradiated with the specific purpose of targeting PCDD and PCDF precursor compounds. In this case, the irradiation is absorbed the precursor compounds causing them to be chemically modified to different chemical compounds that do not participate in chemical reactions that result in the formation of PCDD and PCDF compounds.

Abstract: A method of treating flue gas includes the steps of generating a flue gas and removing particulate from the flue gas with a first particulate removal technique to produce treated flue gas. The treated flue gas is then applied to a high permeability barrier filter to remove additional particulate from the treated flue gas. The high permeability filter includes high permeability filter bags with air permeability greater than 75 actual cubic feet per minute of air flow per square foot of filter surface area at a pressure drop of one half inch water.

Abstract: A system and method that removes an unwanted gas or unwanted gases or volatile liquids from containers or spaces that have only one venthole. The unwanted gases are replaced by a desirable, usually inert gas. The containers may be filled with granular solids of any size or shape; the containers may be of any size or geometry. The method consists of a pump system that applies small pressure oscillations to the single vent hole. These oscillations compress and expand the gas in the container. The resulting gas displacements in the container generate vortices in the gas spaces between the granular solids which mix the gases, replacing the unwanted resident gas by a desirable gas. The theory is related to the dispersion in porous media. Experiments are presented that document the time needed for the washout of the unwanted resident gas.

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: 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: This invention provides a flue gas treating process for removing sulfur oxides and dust from exhaust gas containing sulfur oxides and dust by using an absorption tower into which an absorbing fluid containing an alkaline agent is sprayed, comprising the steps of equipping the absorption tower with integrally formed dust collection means comprising dust collecting plates and discharge electrodes, and with dust separation means for sweeping off the dust collected by the dust collection means; and treating the exhaust gas in the dust collection means and subsequently cleaning the exhaust gas in the absorption tower, whereby desulfurization and dust removal are effected while sweeping off the collected dust by the dust separation means. Thus, desulfurization and dust removal can be effected in a simple manner, and the capacity of an electrostatic precipitator installed on the upstream side can be reduced.

Abstract: The invention discloses a device for filtering internal combustion engine exhaust gases, comprising an electrostatic filtering chamber equipped with electrostatic filtering means, a line for supplying gases into the chamber, in fluid communication with an inlet of the chamber, at one of the ends of the supply line, the other end of the supply line being provided with an opening having an inlet orifice adapted to allow the penetration of the exhaust gases and of a flow of ambient air for cooling the exhaust gases. In this device, the means for drawing the exhaust gases and the air flow are mounted downstream of an outlet of the chamber, to allow the mixture of air and gases to pass into the said chamber and reject the filtered gases into the environment and a filter for coarse solid particles and droplets derived from the mixture is mounted in the chamber, upstream of the electrostatic filtering means.

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: The dust concentration of the flue gas leaving an electrostatic precipitator and introduced into an absorption tower of a desulfurizer is adjusted to a level of 100 to 500 mg/Nm.sup.3. At the same time, a dust slurry having a higher dust concentration is separated and withdrawn from the slurry within the aforesaid absorption tower, and then subjected to a solid-liquid separation treatment. Thus, solid matter containing dust at a high concentration is extracted and discharged out of the system of the desulfurizer.

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: 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: 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: A clog-resistant filter and method for extracting fine particulate contaminants, such as smoke, from a gaseous fluid stream, such as air, uses an induced voltage electrode to efficiently capture the contaminant particles in a filter material whose pores are many times larger than the diameter of the particles to be captured. The filter material is physically so configured to further enhance that interaction and is disposed between at least a pair of electrodes of opposite polarity.

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: A method and apparatus for simultaneously preheating cullet and removing pollutants from glass furnace gases is disclosed. Raw moist cullet having fine glass dust material and other impurities adhered to its surface is heated by furnace gases which remove the moisture and the impurities by entrainment. The dry, clean cullet is then electrically charged and used to filter the exhaust gases which have been electrostatically charged.

Abstract: A method for removing pollutants from a combustor flue gas. The method includes the steps of supplying sorbent to a baghouse having a filter bag therein until the filter bag is coated with a predetermined amount of sorbent and introducing the flue gas into the baghouse. Pollutants in the flue gas are sorbed by the sorbent on the filter bag. A system is provided for performing the method of the invention.

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: The present invention is directed to a method of removing aerosols using a radiation effect.

Abstract: The invention is a method for reduction of sulfur trioxide in flue gases which includes (a) combusting air and petroleum coke in a combustion zone to produce a particulates, sulfur trioxide, and sulfur dioxide-containing combustion product gas; (b) passing the combustion product gas from step (a) to a dry electrostatic precipitator for removal of particulates and recovering the combustion product gas substantially free of particulates, or alternatively rearranging the steps so so that step "b" follows steps "c" and "d"; (c) admixing particulates with the combustion product gas from step (b), to produce a first mixture; (d) passing the first mixture from step (c) to an air preheater for cooling the first mixture and heating the air for combustion with the petroleum coke, wherein the sulfur trioxide in the first mixture condenses on the particulates, to produce a second mixture containing combustion product gas containing sulfur trioxide condensed on particulates and sulfur dioxide; (e) passing the second mixtu

Abstract: Disclosed is a process for removing emissions, originated in the manufacturing industry, especially from polymerization operations and thermoplastic polymer processing operations which includes collecting the air, containing the emissions, directing the air, containing the emissions through a first heat exchanger thereby cooling the air, directing the air, exiting the first heat exchanger, through a second heat exchanger, thereby cooling the air, directing the air exiting the second heat exchanger to a liquid removal system and directing the air, exiting the liquid removal system through the first heat exchanger, thereby heating the air.

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: Disclosed is a process for removing emissions, originated in the manufacturing industry, especially from polymerization operations and thermoplastic polymer processing operations by collecting the air, containing the emissions, cooling the air, directing the air to a liquid removal system and heating the air.

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: An electrostatically stimulated air filter and process, contemplates a housing having an fluid intake and a fluid exhaust; a upstream electrode, disposed downstream of the fluid intake, for carrying a ground potential; a filter, disposed downstream of the prefilter, for filtering out contaminants in the fluid; an ionizing electrode, disposed between the filter and the prefilter, for carrying a second potential; and a downstream electrode, disposed downstream of the filter, for carrying a ground potential; and a fan, downstream of the filter, for driving air through the prefilter and the filter. Ionization of incoming fluid occurs as a result of electric fields generated by the downstream electrode, the ionizing electrode, and the upstream electrode. The filter comprises an upstream dielectric layer and a downstream conductive layer, usually fibers coated with activated carbon powder.

Abstract: A multi-layered electrostatic filter and method of filtration incorporating an insulated poly glass charging element which is a grid of sufficient width to allow the air flow through the charging element to supply a static charge to the charging element and to allow trapped particles to gather and combine or coagulate along the charged element prior to reaching a dust trap which is a second layer of polypropylene filters. The initial charge is generated by friction from the dust and the air passing through a first polypropylene layer. Polypropylene is used in order to provide an insulating frame and insulating dust filters on either side of the poly glass charging element. Progressively fine layers provide for multiloading of particulate material.

Abstract: The steps of the method of the invention are preferably practice on apparatus consisting of components arranged in a closed system for removing particulate matter and gases from a polluted gas stream that includes a sorbent particulate charging and injection gun for electrostatically charging sorbent particles and injecting them into a polluted gas stream to charge and agglomerize pollution particulates therein, the stream flowing into a collection system housing that contains a series of moving and static bed filters and provides for operations at pressures less than atmospheric, and at temperatures up to two thousand (2000) degrees F. The filter beds are maintained across the housing and spaced apart from front to back therein, each filter containing a media material selected for removing the charged agglomerized pollution and sorbent reacted particulates and reacting with gases in the polluted gas stream, providing for removal thereof to clean that gas stream that is then vented to atmosphere.

Abstract: A method and apparatus for eliminating electric charges in a clean room is disclosed involving removing fine and superfine grains from air in the clean room, and generating ions in the thus purified air inside the room.