3m Innovative Properties Company

Simon J Smith

Larry A Brey

Glenn E Weagle

Jamie A Hern

Gary E Dwyer

Pierre Legare

Andrew Murphy

Air filtering devices are disclosed that contain a first filter cartridge having a cartridge inlet and a cartridge outlet and a curved filter bed having a concave surface disposed such that air to be filtered passes through the inlet, the curved filter bed, and the outlet. The air filtering devices also contain a blower assembly having a blower inlet in fluid communication with the cartridge outlet and a blower outlet, the blower assembly includes a motor proximate to the concave surface of the curved filter bed. The motor has a rotational axis such that the rotational axis is adjacent to the center of curvature of the curved filter bed. The air filtering device may be used in powered air purifying respirators.

Air filtration device

Filter systems that are effective against a broad range of contaminants including HCN, cyanogen chloride (CK), acid contaminants. and basic contaminants such as ammonia without the need (but with the option, if desired) for using molybdenum or chromium containing materials. The filtering systems of the present invention include a tungsten-based material and other impregnants incorporated into a substrate such as filter media particles.

Broad spectrum filter system including tungsten-based impregnant and being useful for filtering contaminants from air or other gases

Filter systems that are effective against a broad range of contaminants including HCN, cyanogen chloride (CK), acid contaminants and basic contaminants such as ammonia without the need (but with the option, if desired) for using molybdenum or chromium containing materials. The filtering systems of the present invention include a tungsten-based material and other impregnants incorporated into a substrate such as filter media particles.

An approach for beneficially incorporating both a solid organic impregnant and a fluid impregnant into filter media particles without the presence or addition of one unduly affecting the performance of the other. The present invention achieves impregnation by combining sublimation and non-bulk absorption techniques. These techniques may be carried out in sequential, simultaneous, overlapping, and/or alternating fashion, or the like. The invention is especially suitable when the filter media particles already contain or are to contain one or more other impregnants, whose function or presence might be adversely affected when conventional methods are used to add the solid organic and fluid materials.

Sublimation of solid organic compounds onto substrate surfaces in the presence of a fluid impregnant

Filter medium includes at least two kinds of filter media particles. A first plurality of filter media particles includes an extended surface area substrate comprising at least one transition metal impregnant. A second plurality of filter media particles includes an extended surface area substrate comprising a tertiary amine impregnant. In preferred embodiments, at least one and preferably both of the kinds of filter media particles is/are substantially free of chromium, and more preferably contain no detectable chromium. The filtering medium has very broad filtering capabilities. The filtering medium successfully achieves performance levels mandated both by applicable industrial filter approval specifications and by international military filter performance specifications.

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Glenburnie, Canada

Simon J Smith