Abstract: Methods and systems for filtering pressurized air used to control a compressor bleed valve of a gas turbine engine are provided. One method comprises receiving the pressurized air in a conduit via an inlet of the conduit, releasing a first portion of the pressurized air out of the conduit via an outlet of the conduit, releasing a second portion of the pressurized air from the conduit via a port disposed between the inlet and the outlet of the conduit, directing the second portion of the pressurized air from the port to a filter along an upward flow path, filtering the second portion of the pressurized air using the filter, and directing the second portion of the pressurized air from the filter toward the compressor bleed valve.

Abstract: A filter medium including: a porous first support; nanofiber webs respectively stacked at the upper and lower parts of the first support, and made of a plurality of nanofibers of which the diameters have a standard deviation of 300 nm or less; and a porous second support interposed between the first support and the nanofiber web. The filter medium is implemented by fibers having uniform diameters, and thus is easily manufactured to have a predetermined pore diameter and simultaneously has excellent uniformity of the pore diameters, thereby having excellent filtering efficiency and being more suitable when selectively separating specific objects. Backwashing is enabled at uniform pressure during backwashing such that high cleaning power is obtained. The filter medium has excellent water permeability and excellent mechanical strength so as to minimize the shape and structural deformation and damage of the filter medium.

Abstract: The present invention relates to a microporous polymeric battery separator comprised of a single layer of enmeshed microfibers and nanofibers. Such a separator accords the ability to attune the porosity and pore size to any desired level through a single nonwoven fabric. As a result, the inventive separator permits a high strength material with low porosity and low pore size to levels unattained. The combination of polymeric nanofibers within a polymeric microfiber matrix and/or onto such a substrate through high shear processing provides such benefits, as well. The separator, a battery including such a separator, the method of manufacturing such a separator, and the method of utilizing such a separator within a battery device, are all encompassed within this invention.

Abstract: Colloids comprising inorganic nanocrystals dispersed in a molten salt or a liquid metal are provided. The molten salt may comprise an ion which is a Lewis acid or a Lewis base in the presence of the inorganic nanocrystals. Solid composites formed from the colloids are also provided. Methods of using the colloids as media for inducing chemical transformations using the inorganic nanocrystals are also provided.

Abstract: A polymer composite comprising quantum dots; said polymer composite comprising: (a) quantum dots; (b) polymerized units of a first compound having at least one readily polymerizable vinyl group, a molecular weight from 300 to 20,000 and at least one continuous acyclic hydrocarbyl chain of at least five carbon atoms; and (c) polymerized units of a second compound having at least one readily polymerizable vinyl group and a molecular weight from 100 to 750; wherein a readily polymerizable vinyl group is part of a (meth)acrylate ester group or is attached directly to an aromatic ring, and the molecular weight of the first compound minus the molecular weight of the second compound is at least 100.

Abstract: Polymeric sorbents for reactive gases are provided. More particularly, the polymeric sorbents are a reaction product of a divinylbenzene/maleic anhydride precursor polymeric material with a nitrogen-containing compound. The polymeric sorbent has nitrogen-containing groups that are covalently attached to the polymeric sorbent. The nitrogen-containing groups include a primary amino group, a secondary amino group, a tertiary amino group, or a combination thereof. Additionally, methods of sorbing reactive gases on the polymeric sorbents and compositions resulting from the sorption of reactive gases on the polymeric sorbents are provided.

Abstract: The present disclosure provides a high refractive index acrylic formulation embedded with sub-10 nm metal oxide nanocrystals. The formulation is ideal for high refractive index, high transparency coating for a variety of optical applications including OLED lighting.

Abstract: A monolithic separation membrane structure comprises a porous monolithic substrate and a separation membrane. The monolithic substrate includes a first end surface, a second end surface and a plurality of through-holes respectively passing from the first end surface to the second end surface. The separation membrane is formed on an inner surface of the respective plurality of through-holes. The surface roughness Ra of the separation membrane is no more than 1 micrometer and the thickness of the separation membrane is no more than 5 micrometers.

Abstract: Nonaqueous redox flow batteries (RFB) hold the potential for high energy density grid scale storage, though are often limited by the solubility of the redox-active species in their electrolytes. A systematic approach enables an increase the concentration of redox-active species in electrolytes for nonaqueous RFB, starting from a metal-coordination-cation-based ionic liquid. As an example, starting with an ionic liquid consisting of a metal coordination cation (MetIL), ferrocene-containing ligands and iodide anions can be substituted into the original MetIL structure, enabling a nearly 4× increase in capacity compared to original MetIL structure. Application of this strategy to other chemistries, optimizing electrolyte melting point and conductivity could yield >10 M redox-active electrons.

Abstract: An epoxy resin composition excellent in storage stability and curability is provided. Particularly, a compound of general formula (I) and an epoxy resin composition containing the compound as a curing agent are provided. In formula (I), R1 is a hydrocarbon group optionally containing a nitrogen atom and capable of forming a cyclic structure optionally having a substituent; R2 is a hydrogen atom, an alkyl group, or an aryl group or is taken together with R1 to form an unsaturated bond; R3 is a hydrogen atom, an alkyl group, or an aryl group; and X is a dicyanamide ion or a thiocyanate ion.

Abstract: An antenna includes an ion exchange material and at least one polymer member coupled to a communication circuit. The at least one polymer member is configured to, responsive to receiving a bias voltage, interact with the ion exchange material to change electrical conductivity of the at least one polymer member.

Abstract: An electrochemical gas sensor includes an electrolyte including at least one ionic liquid which includes an additive portion including at least one organic additive, at least one organometallic additive or at least one inorganic additive.

Abstract: The present invention relates to a method for preparing polymer-nanoparticles having a core-shell structure by uniformly coating a polymer on metal and inorganic particles, polymer-nanoparticles prepared thereby, and a polymer-nanoparticle composite comprising the same, and more specifically, a method for preparing polymer-nanoparticles having a core-shell structure by uniformly coating a polymer on metal and inorganic particles, polymer-nanoparticles prepared thereby, and a polymer-nanoparticle composite including the same, wherein when forming a polymer coating layer on surfaces of particles that are not subjected to separate surface treatment, excessive polymers uncoated on nanoparticles are easily removed by adding to an ionic liquid or an apolar solvent so that the polymer coating layer is formed with a nanometer-scale uniform thickness and a dense coating density, thereby showing excellent dispersibility in a polymer matrix.

Abstract: The present invention relates to a manufacturing method of a porous ceramic material, which includes the following steps: mixing a silicate material and a porogen to obtain a premix, wherein the silicate material includes sodium silicate and other compounds being at least one selected from the group consisting of oxides, nitrides, and carbides; drying the premix to obtain a silicate aggregate; mixing the silicate aggregate and an adhesive to obtain an injection molding material, wherein in a weight percentage, the silicate aggregate is in the range of from 50% to 60%, the adhesive is in the range of from 40% to 50%; injection molding the injection molding material to obtain a green body; and degumming and calcinating the green body successively to obtain the porous ceramic material.

Abstract: A liquid electrolyte formed by reacting phosphoric acid (H3PO4) in the liquid state with silicon tetrachloride (SiCl4), thereby forming a fluid suspension. The fluid suspension is heated to yield a liquid electrolyte including phosphoric acid (H3PO4), pyrophosphoric acid (H4P2O7), and a particulate solid comprising a silicophosphoric acid, wherein the silicophosphoric acid is an acidic molecular compound including silicon and phosphorus. A concentrated silicophosphoric acid composition prepared by removing most of the liquid from the liquid electrolyte is dissolved in water to yield a homogeneous solution. The homogeneous solution is dried to yield a solid electrolyte. In some cases, the homogenous solution is dried on a substrate to coat at least a portion of the substrate with a proton conductive solid electrolyte. A fuel cell may include the liquid electrolyte, the solid electrolyte, or the coated substrate.

Abstract: Polymeric ionic liquids, methods of making and methods of using the same are disclosed.

Abstract: The invention relates to a coated particle filter (3), in particular wall-flow filter, having a length (L). According to the invention, at least two zones (4, 5) which have different coatings are provided along the length (L). The invention also relates to a catalytic converter (2), wherein the catalytic converter (2) is formed with a coating which has a washcoat coating layer as a lower coating layer, onto which palladium is deposited. The invention finally relates to a device (1) for the purification of exhaust gases, in particular exhaust gases of diesel-engined motor vehicles, comprising a catalytic converter (2) and a coated particle filter (3) of length (L) positioned downstream of the catalytic converter (2), wherein the particle filter (3) and the catalytic converter (2) are designed in accordance with the invention.

Abstract: A filter for internal combustion engines, includes a rigid external casing provided with at least an inlet for a fluid to be filtered and an outlet for the fluid when filtered, and a filter cartridge located internally of the external casing, which includes a plurality of tubular filter walls arranged parallel to one another which are destined to be crossed by the fluid flowing from the inlet towards the outlet of the external casing; the external casing being conformed such as to delimit a pouch a transversal section of which, performed along a perpendicular plane to axes of the tubular filter walls, exhibits a prevalent line of development and a small width with respect to the prevalent line of development; the tubular filter walls being arranged internally of the pouch, side by side with one another, forming a single row which follows the prevalent line of development of the pouch.

Abstract: A wall flow type particulate filter (24) adapted to be arranged in an exhaust passage of an internal combustion engine in which combustion is performed in an excess of oxygen carries a solid acid. The solid acid has an acid strength which is higher than the acid strength of sulfurous acid and lower than the acid strength of sulfuric acid.

Abstract: The present invention is characterized in that a filter made of resin comprises a through-hole film portion (14); and a structure reinforce portion (13), wherein a through-hole (15) is provided in a through-hole film portion (14), the thickness of the through-hole film portion (14) is from 0.5 to 2.0 ?m, the bore of the through-hole (15) is from 0.05 to 0.5 ?m, the thickness of the structure reinforce portion (13) is bigger than the thickness of the through-hole film portion (14), the structure reinforce portion (13) encloses the through-hole film portion (14), a damage-reduction structure is provided on the upper surface of the structure reinforce portion (13), and wherein, the damage-reduction structure may be an uneven structures.

Abstract: A filtering device features a ceramic filter body for filtering a fluid flow, the filter body consisting of a wavy layer and a flat layer and the wavy and flat layer being wound in a spiral-shaped manner. The wave length of the waves increases from the inside to the outside with increasing distance to the longitudinal axis of the filter body such that the wave troughs and the wave peaks of at least two radially adjacent windings each lie on a common radial plane.

Abstract: [Problem] To provide a filter whose initial collection efficiency can be increased and whose pressure loss increase can be suppressed. [Means to solve the problem] A ceramic filter includes: numerous crystalline masses bound to one another each formed of aggregation of columnar crystals, wherein a number of large diameter pores are present between the numerous crystalline masses, and small diameter pores are present between the numerous columnar crystals forming the crystalline mass.

Abstract: An exhaust gas purification system includes a diesel particulate filter (“DPF”) which collects particulate matter (“PM”) in exhaust gas, an exhaust pipe injector which performs exhaust pipe injection, and a DPF regeneration control unit which performs temperature rise control of an exhaust gas temperature by the exhaust pipe injection to regenerate the DPF when the PM collected by the DPF exceeds a fixed amount and which, during the regeneration, integrates an amount of time during which the exhaust gas temperature exceeds a PM combustion temperature and completes the regeneration when an integrated value thereof reaches a set regeneration completion value. The DPF regeneration control unit aborts the regeneration when, during regeneration, a total amount of the exhaust pipe injection exceeds an upper limit before the integrated value.

Abstract: A retaining seal material includes inorganic fibers, inorganic particles adhering to surfaces of the inorganic fibers, a first principal surface, and a second principal surface. A mean particle diameter of the inorganic particles in a vicinity of a center in a thickness direction of the retaining seal material is smaller than at least one of a mean particle diameter of the inorganic particles in a vicinity of the first principal surface and a mean particle diameter of the inorganic particles in a vicinity of the second principal surface.

Abstract: The composite microporour filter material comprises a base-cloth layer, an upper adhesion layer attached to a top side of the base-cloth layer, and a lower adhesion layer attached to a bottom side of the base-cloth layer. The base-cloth layer is made of either polymide yarn base-cloth, polysulfoneamide yarn base-cloth, or polytetrafluoroethylene filament base-cloth. The upper adhesion layer is made of a mixture of polysulfoneamide short-staple and polymide short-staple; the lower adhesion layer is made of a pure polysulfoneamide short-staple. The upper adhesion layer and the lower adhesion layer are attached to two sides of the base-cloth layer by entangling which is adopted by needle punching, spunlacing or a combination thereof. The present filter material is temperature-resistant and corrosion-resistant and has features of a low manufacturing cost and the high filter precision.

Abstract: An exhaust gas purification system with which a frequency of diesel particulate filter (“DPF”) regeneration requests can be reduced during long low idle regeneration, thereby improving convenience, including a control unit that performs regeneration control on a DPF provided at an exhaust pipe of an engine. The control unit includes a particulate matter (“PM”) accumulation amount predictor for predicting the amount of PM accumulated by calculating a cumulated value of the PM in an idling state. The control unit starts calculating the cumulated value of the PM by the PM accumulation amount predictor after a first predetermined time has elapsed since a detection of the idling state.

Abstract: Articles such as filter media, which include dendrimers and/or other components, are provided. The filter media may further include a water repellant (e.g., a fluorinated species) to impart desirable properties to the media such as high water repellency. The filter media may also have a high efficiency as a function of pressure drop (i.e., high gamma values). In some embodiments, the filter media includes a fiber web which may be formed of various components such as glass fibers. The fiber web can also include additional components such as synthetic fibers, binder components, as well as other additives. The media may be incorporated into a variety of filter element products.

Abstract: Disclosed are ceramic bodies comprised of composite cordierite aluminum magnesium titanate ceramic compositions and methods for the manufacture of same.

Abstract: A hybrid mounting mat for mounting a catalyst support structure within a housing in an exhaust gas treatment device. The exhaust gas treatment device includes an outer housing, a fragile catalyst support structure, and a mounting mat disposed in the gap between the housing and the fragile catalyst support structure. Additionally disclosed are methods of making the hybrid mounting mat and for making an exhaust gas treatment device incorporating the mounting mat.

Abstract: The objective of the present invention is to provide an air filter medium having a lower pressure drop and higher efficiency as compared to an air filter medium currently in use. This objective is achieved by providing an air filter medium characterized by comprising glass short fibers as its main fibers in which the constituent fibers are dispersed uniformly and, when the constituting fibers at a diluted concentration of 0.04% by mass are allowed to stand for 12 hours, the sedimentation volume is 450 cm3/g or greater.

Abstract: The invention is directed to a vessel for separating solid particles from a gas containing solid particles, said vessel comprising a plate provided with openings across the vessel such that the plate divides the vessel in a first and second space, a number of filter elements extending from the openings into the first space, a vessel opening for receiving the gas containing solid particles, fluidly connected to the first space, an vessel outlet opening for discharge of solids, fluidly connected to the first space and a vessel outlet opening for gas, fluidly connected to the second space. The first space further comprises one or more cyclone separation devices having an inlet fluidly connected to the vessel opening for receiving the gas containing solid particles, a cyclone gas outlet fluidly connected to the first space and a solids cyclone outlet.

Abstract: A honeycomb filter includes a plurality of cells and porous cell walls. The plurality of cells include exhaust gas introduction cells and exhaust gas emission cells. The porous cell walls each have a porosity of 55% or acre but not more than 70%. The porous cell walls include pores with a pore diameter of 40 ?m or more. The pores have a pore volume occupying 10% or more of a total pore volume of the porous cell walls. The exhaust gas emission cells have an average cross sectional area larger than an average cross sectional area of the exhaust gas introduction cells in the cross section perpendicular to the longitudinal direction of the plurality of cells. A total volume of the exhaust gas introduction cells is larger than a total volume of the exhaust gas emission cells.

Abstract: A holding sealing material includes a mat, an inorganic binder and an organic binder. The mat includes inorganic fibers and has an upper part, a center part, and a lower part in a thickness direction. The inorganic binder is loaded on the mat. The organic binder is loaded mainly on the upper part and the lower part of the mat. The holding sealing material is disposed between an exhaust gas-treating body and a casing for housing the exhaust gas-treating body to form an exhaust gas purifying apparatus.

Abstract: A parallel passage fluid contactor structure for chemical reaction processes has one or more segments, where each segment has a plurality of substantially parallel fluid flow passages oriented in an axial direction; cell walls between each adjacent fluid flow passages and each cell wall has at least two opposite cell wall surfaces. The structure also includes at least one active compound in the cell walls and multiple axially continuous conductive filaments either embedded within the cell walls or situated between the cell wall surfaces. The conductive filaments are at least one of thermally and electrically conductive, are oriented in axially, and are in direct contact with the active compound, and are operable to transfer thermal energy between the active material and the conductive filaments. Heating of the conductive filaments may be used to transfer heat to the active material in the cell walls. Methods of manufacturing the structure are discussed.

Abstract: A self-regenerating chitosan based filter medium for disinfecting and purifying organic pollutants and other pollutants in a gas or liquid is disclosed herein. Porosity and surface charge of said filter medium is manipulative/tunable by varying one or more of the following parameter(s): concentration of chitosan, crosslinking density, amount of copolymers and additives, freezing temperature, freezing profile, and/or types of crosslinker used. The present filter medium is capable of self-regenerating under exposure to ultra-violet light for sufficient time and removing over 90% of the pollutants from each influent flowing through the filter medium.

Abstract: An exhaust gas purification system with which diesel particulate filter (“DPF”) regeneration can be continued even when deceleration occurs during the DPF regeneration. The system includes a regeneration deceleration period intake/exhaust control unit that, when a vehicle decelerates during the DPF regeneration, increases an exhaust gas flow rate through an exhaust pipe by controlling respective openings of an exhaust gas recirculation (“EGR”) device and an intake throttle and adjusting a turbocharging amount of a high pressure stage turbocharger.

Abstract: A porous membrane, comprising a blend of a first powder of metal particles of the first average size and a second powder of metal particles of a second average size, the first powder and the second powder sintered together. The first average size is five to fifty times greater than the second average size. The porous membrane comprises from 40% to 60% by weight of the first powder.

Abstract: A exhaust gas purification device is structured such that it is possible to improve an assembling work ability or a maintenance work ability of gas purifying bodies or exhaust gas purifying cases. In an exhaust gas purification device provided with gas purifying bodies which purify an exhaust gas discharged by an engine, and a gas purifying housing which is provided with the gas purifying bodies therein, the exhaust gas purification device is structured such that a support bracket which supports the gas purifying housing is provided, a bolt hole is formed in the support bracket, an insertion guide is formed in the support bracket, and an attaching bolt is engaged with and disengaged from the bolt hole via the insertion guide.

Abstract: The present invention relates to device and method for reducing soot particles. The device for reducing soot particles includes a first filter provided to an exhaust gas flow passage through which exhaust gas from a diesel engine flows to have a predetermined volume of a plurality of grains to be operated as a volumetric filtration system, and a second filter provided to a predetermined position of the second filter to be operated as a surface filtration system.

Abstract: A method for engine-out soot flow rate prediction of an exhaust gas treatment system is provided. A measured level of oxides of nitrogen in the exhaust gas treatment system is received. An engine fuel injection timing and air-fuel ratio of an engine producing the oxides of nitrogen are also received. An engine timing factor is determined based on the engine fuel injection timing. An engine air-fuel ratio factor is determined based on the engine air-fuel ratio. An engine-out soot flow rate prediction is generated based on the measured level of oxides of nitrogen, the engine timing factor, and the engine air-fuel ratio factor.

Abstract: A ceramic honeycomb structure suitable for particulate filters, having an inlet face and an outlet face, comprising a plurality of inlet cells and a plurality of outlet cells extending through the structure from the inlet face to the outlet face, the inlet cells being open at the inlet face and closed where adjoining the outlet face, and the outlet cells being open at the outlet face and closed where adjoining the inlet face. The inlet and/or outlet cells are quadrangular in cross-section and are arranged in an alternating pattern; the outlet cells may have a cross-sectional area generally smaller than that of inlet cells and no point of a given inlet cell is closer to an adjacent inlet cell than to an adjacent outlet cell. A process for preparing the ceramic honeycomb structure is also disclosed.

Abstract: A device for at least one self-heated and dense ceramic tube for gas separation. The device includes at least one dense ceramic tube in an environment accessible to a mixture of gases, the at least one tube acting as a diffusion membrane for separating at least one gas from the mixture of gases. Two electrical contacts are provided which allow connecting a power supply to the ceramic tube and driving an electric current through the ceramic tube. The contacts can be in the farm of short coils wrapped around the ceramic tube at difference places. When a voltage is applied to the contacts, an electrical current flows from one contact to the other through the ceramic tube. The current in the ceramic tube heats the tube. Thus, the tubes heat themselves. The hot tube allows separating a gas from the mixture of gases. The driving force for the diffusion is achieved by a pressure difference generated by pumping at the side of the separated gas and pressing at the side of the mixture of gases.

Abstract: An object of the present invention is to detect any breakdown or failure of a particulate filter more appropriately. A failure detecting apparatus for detecting failure of a particulate filter according to the present invention comprises an acquiring section which acquires an amount of PM contained in an exhaust gas allowed to outflow from the particulate filter; a regeneration process executing section which executes a filter regeneration process for oxidizing and removing PM deposited in the particulate filter; and a failure judging section which judges that the particulate filter is in the failure state if a decreased amount of the amount of PM contained in the exhaust gas acquired by the acquiring section, during a predetermined period of time as started from a point in time at which the execution of the filter regeneration process performed by the regeneration process executing section is completed, is not equal to or larger than a predetermined reference amount.

Abstract: An exhaust gas treatment system for an internal combustion engine is provided comprising an exhaust gas conduit, a particulate filter (“PF”) device, a hydrocarbon source and an electronic control module including operative logic which when implemented. The PF has a filter structure for removal of particulates in the exhaust gas and is selectively regenerated based on an amount of particulates trapped within the filter structure of the PF device. The control module is in communication with the internal combustion engine and the hydrocarbon source, and receives a regeneration signal indicating the amount of particulates trapped within the filter structure of the PF device. The electronic control module includes control logic for monitoring the internal combustion engine prior to a regeneration event. The electronic control module includes control logic for determining a plurality operating parameters of the internal combustion engine based on the monitoring.

Abstract: The present invention aims to provide a honeycomb structure capable of preventing a plugging failure and forming cracks by heat shock which are caused by a cell having a small cross-section.

Abstract: The invention relates to a reactor (1) for gasifying biomass, in particular wood, comprising a feeder chute (7) and an ash bed arranged beneath the feeder chute (7). According to the invention, a device is provided by means of which biomass adhering to the feeder chute (7) can be detached, and/or a heat exchanger is provided by means of which a product gas generated from the biomass gives oil heat to the biomass subsequently conveyed in the feeder chute (7) and to oxidation air. The invention further relates to a fine filter (29) for cleaning a product gas generated from biomass. According to the invention, the filter medium contains biomass. Furthermore, the invention relates to a method for gasifying biomass in a reactor (1), in particular a reactor (1) according to the invention, to form a product gas. According to the invention, biomass adhering to the feeder chute (7) is detached and/or heat is given off to biomass and to oxidation air by the product gas.

Abstract: The present invention is intended to detect a failure of a PM filter with a higher degree of accuracy. The present invention is provided with: a PM trapping efficiency calculation part to calculate a PM trapping efficiency (which is a proportion of an amount of particulate matter trapped with respect to an amount of inflow particulate matter) based on an amount of inflow particulate matter obtained by an inflow particulate matter obtaining part, and an amount of outflow particulate matter detected by a PM sensor; and a failure detection part to make a determination that a failure has occurred in the PM filter, in cases where there has appeared a tendency for the PM trapping efficiency to decrease during a period of time until the execution of the following filter regeneration processing is started after the completion of execution of the filter regeneration processing.

Abstract: A particulate matter detecting apparatus for an internal combustion engine that can estimate a discharge amount of the particulate matter accurately. The particulate matter detecting apparatus for an internal combustion engine, comprises: a sensor disposed at an exhaust passage of the internal combustion engine, the sensor including a pair of electrodes for detecting particulate matter in an exhaust gas; means for estimating a discharge amount of the particulate matter based on an output of the sensor, and means for acquiring a predetermined parameter that serves as an index for a rate with which the particulate matter in the exhaust gas is deposited on the sensor. The discharge amount estimating means corrects an estimated value of the discharge amount of the particulate matter based on the parameter acquired by the parameter acquiring means.

Abstract: The present invention is directed, in part, to air filtration media, air filtration media packs, air filtration elements, and methods of making air filtration media, media packs, and filtration elements. The air filtration media typically has a fiber composition that is primarily cellulose fibers, the media having a low solidity and low basis weight and being suitable for forming of structured flutes into the media. In certain embodiments a resin is added such as a solvent based resin.

Abstract: Inner cases are connected to outer cases through joining flanges which protrude toward outer peripheries of the outer cases. A plurality of combinations each including filters, the inner cases, and the outer cases are provided. Both the joining flanges are sandwiched and fixed between a pair of sandwiching flanges, thereby connecting the plurality of outer cases to each other.