Abstract: A filter for a gas mask has a concave outlet wall and a convex inlet wall with a particulate filter bed that has a uniform depth and conforms substantially to the shape of the inlet and outlet wall. The side wall can have an elliptical, circular or convex shape to conform to the curvature of the wearer's face, or a planar shape. The filter an be a double particulate filter element and a double adsorption filter element configured for axial airflow therethrough with a bifurcated flow pattern. The adsorption filter element comprises a granulated charcoal, a composite material having carbon particles combined with binder particles, or an immobilized bed of charcoal granules and EVA-coated fibers.

Abstract: A gas mask filter canister of varying shapes is filled by orienting the a fill opening to face upwardly, introducing into the fill opening a particulate filter material, and vibrating the filter canister at a frequency and amplitude, and for a time until a predetermined packing density is reached. The invention can be used to fill elliptical or other odd shaped filter canisters having a concave profiles to conform closely to the curvature of the wearer's face.

Abstract: A gas mask filter canister of varying shapes is filled by orienting the a fill opening to face upwardly, introducing into the fill opening a particulate filter material, and vibrating the filter canister at a frequency and amplitude, and for a time until a predetermined packing density is reached. The invention can be used to fill elliptical or other odd shaped filter canisters having a concave profiles to conform closely to the curvature of the wearer's face.

Abstract: A filter for a gas mask has a concave outlet wall and a convex inlet wall with a particulate filter bed that has a uniform depth and conforms substantially to the shape of the inlet and outlet wall. The side wall can have an elliptical, circular or convex shape to conform to the curvature of the wearer's face, or a planar shape. The filter an be a double particulate filter element and a double adsorption filter element configured for axial airflow therethrough with a bifurcated flow pattern. The adsorption filter element comprises a granulated charcoal, a composite material having carbon particles combined with binder particles, or an immobilized bed of charcoal granules and EVA-coated fibers.

Abstract: A filter for a gas mask has an elliptical or circular, convex shape to conform to the curvature of the wearer's face, or a planar shape. The filter comprises a double particulate filter element and a double adsorption filter element configured for axial airflow therethrough with a bifurcated flow pattern. The adsorption filter element comprises a granulated charcoal, a composite material having carbon particles combined with binder particles, or an immobilized bed of charcoal granules and EVA-coated fibers.

Abstract: A filter for a gas mask has an elliptical or circular, convex shape to conform to the curvature of the wearer's face, or a planar shape. The filter comprises a double particulate filter element and a double adsorption filter element configured for axial airflow therethrough with a bifurcated flow pattern. The adsorption filter element comprises a granulated charcoal, a composite material having carbon particles combined with binder particles, or an immobilized bed of charcoal granules and EVA-coated fibers.

Abstract: A mechanical refrigeration process in which two or more systems are connected in series to provide successively lower temperature levels. Each system utilizes mixtures of refrigerants and/or inert gases having different boiling points. The mixture is compressed to a suitable pressure and compression heat is rejected to the environment. The mixture is cooled by heat exchange with mixture returning to the compressor. The liquid and gas phases are separated and the separated gas mixture is further cooled to form liquid, by heat exchange with mixture returning to the compressor. The liquid is expanded to a given lower pressure to achieve the desired low temperature. The expanded fluid absorbs heat to provide refrigeration. The liquid expanded to the lower pressure is mixed with the used fluid which absorbed heat to provide refrigeration. The capacity of the system is controlled by throttling the compressor suction.

Abstract: Multiple refrigeration systems, each with refrigerants having a different boiling point, are connected in series to provide successively lower temperatures. Following compression and heat rejection, the refrigerant mixture is cooled by heat exchange with refrigerant returning to the compressor. Gas and liquid phases are separated and the gas is cooled further by heat exchange with mixture returning to the compressor. System capacity is controlled by throttling the compressor suction.

Abstract: An improved pressure swing adsorption cycle which is preferably useful for the continuous production of a relatively minor amount of a purified gas, and a method which is useful to provide a continuous therapeutic supply of oxygen at a level required by an individual patient for the treatment of chronic obstructive pulmonary diseases and other health conditions.

Abstract: A machine for concentrating the oxygen in air for medical purposes utilizing any pressure swing adsorption (PSA) technique and comprising a combination of features to provide a light weight, reliable and compact device, especially suited for home use.

Abstract: A machine for concentrating the oxygen in air for medical purposes utilizing any pressure swing adsorption (PSA) technique and comprising a combination of features to provide a light weight, reliable and compact device, especially suited for home use.