A filter element includes a first bellows which is produced from a first filter medium, in view of the object of providing a filter element which after some service life can be readily modified in such a manner that said filter element again achieves an adequate filtration effect, is characterized in that a second bellows which is produced from a second filter medium is provided, wherein the second bellows is inserted into a recess of the first bellows and the periphery of the second bellows is partly or completely surrounded by the first bellows or wherein the second bellows is placed onto the first bellows in such a manner that the recess is covered by the second bellows and the fold tips of the bellows are aligned with one another.

A method for air purification is disclosed, comprising directing air through a particle removal filter that acts to filter the air for particle phase pollutants to thereby produce particulate filtered air; and directing an amount of the particulate filtered air through a gas removal filter that acts to filter the particulate filtered air for gas phase pollutants to thereby produce gas filtered air; the particle removal filter with the first blower and the gas removal filter with the second blower are housed in different enclosures and they are allowed to operate in a way that; the two different units are selectable to operate separately without connection in a first mode, and to operate together connectively in a second mode; when the two different units are selected to operate together connectively in the second mode, the amount of particulate filtered air directed through the gas removal filter is based on a concentration of particle phase pollutants in the air.

An integrated autonomous air purification device for taking in polluted air, carrying it through the inside of the purification device where it passes through a set of filtering elements (1) that trap the dust particles contained in the air; ultraviolet-light lamps (2) that transform NO.sub.X and CO gases in the air into harmless compounds; an activated carbon filter (4) that traps and eliminates the volatile organic compounds and inorganic acidic gases; second filtering elements (5) that carry out a second filtering; and an extraction hood (6) configured to direct the air coming out of the second filtering elements (5) to at least one nozzle (7) that expels the air to the outside of the purification device.

A refrigerator and an air purifier for a refrigerator are provided. The air purifier may include a case configured to be mounted on an upper surface of a cabinet of a refrigerator and in which inlet holes and an outlet hole are formed, a plurality of fan motor assemblies provided inside of the case to force a flow of air, a plurality of filter assemblies mounted in the case to partition a space between the inlet holes and the plurality of fan motor assemblies and purify suctioned air, a controller that controls driving of the plurality of fan motor assemblies, and a gas sensor connected to the controller to detect harmful gas in a kitchen space. The controller may control driving of the plurality of fan motor assemblies through detection of the harmful gas by the gas sensor.

A high-end processing device for purification of exhaust of a diesel engine includes a connection channel, a plurality of catalytic converters, a plurality of direct-passage ceramic filters, and at least one wall-flow filter. The catalytic converters are arranged, in a manner of being spaced from each other, at a front portion of an exhaust gas flow path defined by the connection channel. The direct-passage ceramic filters and the wall-flow filter are arranged, in a manner of being spaced from each other, at a rear portion of the exhaust gas flow path of the connection channel. The direct-passage ceramic filters and the wall-flow filter are impregnated with urea or ammonia and dried so as to reduce nitrogen oxides (NOx) into nitrogen and water to reduce impact to the environment.

A filtration system for a ventilation hood includes a first filter and a second filter, operatively disposed in series. The first filter is configured to be mounted within the ventilation hood, and has an air inlet, an air outlet, and a grease outlet. The second filter includes a filter material with an upstream surface and a downstream surface, an upstream housing element abutting the upstream surface of the filter material, and a downstream housing element abutting the downstream surface of the filter material. The housing elements include openings, and hold the filter material in compression.

An aftertreatment system comprises a SCR system, a first filter, and a second filter disposed downstream of the first filter and a bypass conduit providing a flow path bypassing the second filter. A valve is operatively coupled to the bypass conduit and is moveable between a closed position in which the exhaust gas flows through the second filter, and an open position in which at least a portion of the exhaust gas flows through the bypass conduit. A controller is operatively coupled to the valve configured to adjust the valve based on a first filtration efficiency of the first filter to cause the exhaust gas expelled into the environment from the aftertreatment to have a particulate matter count meeting particulate matter emission standards.

A filtration article including a composite filtration structure, a seal region positioned within the composite filtration structure, and an attachment weld that interconnects the seal region and an outer casing is provided. The composite filtration structure includes a stacked filter material including at least two fluoropolymer membranes and a support layer. The support layer may be formed of a thermoplastic or thermoset polymer. When heated, the polymer in the support layer melts and flows into the fluoropolymer membranes. In exemplary embodiments, the polymer is imbibed through the thickness of the fluoropolymer membranes. The attachment weld may be positioned at any location within the seal region so long as the attachment weld is positioned a distance from the outer periphery of the composite filtration structure. The filtration article is small in size, is lightweight, and may be used as a sterilizing grade filter. Methods of producing the filtration article also provided.

The invention relates to a device for treating fluid mixtures, which contain gases, such as in particular hydrogen (H2), air, nitrogen (N2), or natural gases, and liquids, such as in particular ionic liquids, hydraulic fluid, or process liquids, comprising at least a first separation stage (29) for separating the fluid mixture into a liquid fraction and a gas fraction, which is contaminated with a remaining liquid fraction, from which gas fraction said remaining liquid fraction is removed in at least one further separation stage (67).

An air filter for automobiles includes, a main filter and a prefilter, wherein the prefilter comprises a nonwoven synthetic fiber having an average density of 0.01 to 0.5 g/cm.sup.3 and a moisture absorbent is adsorbed to the prefilter.