Abstract: A collective NBC filtration system (FIG. 1A) for providing positive-pressure purified air to a plurality of subjects in a protected space, or in an environment which cannot be maintained at positive pressure, in conjunction with one or more facepiece fluidly connected to the NBC filtration system. The system comprises: A casing body [102] including a first section [136] defining an inner volume therein, and a second section [138] adjacent to the first section. The second section includes an inlet port [116], The first section has a larger cross-section than the second section, and forms a peripheral first ledge [142] surrounding the second section. At least one NBC filter accommodated in the inner volume. The at least one NBC filter is supported on the first ledge [142], A lid [104] including a central portion [154] and a second ledge [152] surrounding the central portion. The central portion [154] includes a plurality of outlet ports [118], which are sealable.

Abstract: An NBC filtration system whose main components are a filter unit, a blower, a manual air exchange backup unit and a changeover valve. The filter unit is elongated horizontally positioned along a top portion of a wall of the protected space. Inlet and outlet ports of the filter unit are located close to each other near a first extremity of the filter unit. The blower is driven by the electric motor through a second speed increasing transmission enabling rotation of an impeller of the blower. The blower is positioned along the filter unit near a second extremity distal from the inlet and outlet ports; The changeover valve has a tubular housing extending along the filter unit near the first extremity, and an internal displaceable tubular valve member. Each of the components may be replaced with a component of different capacity without effecting the other components.

Abstract: An engine air filter for heavy dust conditions such as used in heavy military and off-road vehicles, including a scavenging system, and a method of operation thereof. The air filter includes: a housing, a precleaner, a permeable filter, and a scavenger system. The scavenger system disposes of particles collected at the precleaner and on the upstream surface of the permeable filter. The scavenger system includes: an air suction source and a three way valve. The three way valve is airflow coupled to the precleaner, to the permeable filter and to the air suction source. The three way valve enables scavenging of the precleaner and the permeable filter alternately. Optionally, the air filter may further includes a pulse jet back-flow flush system.

Abstract: An air filter for heavy dust conditions has an efficient scavenging system. The air filter includes: a housing, a permeable filter, and a scavenger system. The scavenger system disposes of particles collected on the upstream surface of the permeable filter. The scavenger system includes: an air suction source, and a shutter. The shutter is positioned substantially along, typically below, the permeable filter, at a certain distance from a wall, typically the bottom wall, of the housing. The air suction source draws air from a collecting space located between the shutter and the wall of the housing. The shutter is being selectively operated to permit or restrict passage there-through. The air suction source efficiently operates to scavenge particles from the collecting space when the passage through the shutter is at least partially restricted.

Abstract: A collective NBC filtration system (FIG. 1A) for providing positive-pressure purified air to a plurality of subjects in a protected space, or in an environment which cannot be maintained at positive pressure, in conjunction with one or more facepiece fluidly connected to the NBC filtration system. The system comprises: A casing body [102] including a first section [136] defining an inner volume therein, and a second section [138] adjacent to the first section. The second section includes an inlet port [116], The first section has a larger cross-section than the second section, and forms a peripheral first ledge [142] surrounding the second section. At least one NBC filter accommodated in the inner volume. The at least one NBC filter is supported on the first ledge [142], A lid [104] including a central portion [154] and a second ledge [152] surrounding the central portion. The central portion [154] includes a plurality of outlet ports [118], which are sealable.

Abstract: A near ceiling mounted NBC filtration system [10] (FIG. 8) for collective protection shelters having an optimized modular structure. The main building blocks comprising: a filter unit [30], a blower [40], a manual air exchange backup unit [20] and a changeover valve [50]. The filter unit [30] is elongated in shape horizontally positioned along a top portion of a wall of the protected space. An inlet port [36] and outlet port [38] of the filter unit are located in proximity to each other near a first extremity of the filter unit. The blower [40] is driven by the electric motor [42] through a second speed increasing transmission enabling rotation of an impeller of the blower at speeds of above 3000 rpm. The blower [40] is positioned along the filter unit [30] near a second extremity thereof distal from the inlet port and outlet port; The changeover valve [50] comprises a tubular housing extending along the filter unit near the first extremity thereof, and an internal displaceable tubular valve member.

Abstract: A louver type blast valve making use of an aerodynamically configured blade, independently activated by air flow to block a blast shock wave and a subsequent return suction wave. The blast valve (FIG. 6) including a frame and at least one aerodynamically configured blade, independently activated by air flow to block a blast shock and a potentially following return wave. The aerodynamically configured blade having an elongated shape, including at least a steep convex surface and a flat or shallow concave surface, forming a leading edge and a trailing edge at the intersection of the surfaces. The blade being hinged to the frame about a longitudinal axis passing between the steep convex surface and the flat or shallow concave surface.

Abstract: A near ceiling mounted NBC filtration system of collective protection shelters comprising a filter unit, a blower, and an air exchange backup unit [20] (FIG. 5). The air exchange backup unit [20] comprising: a plurality of hinged segments [22a, b, c] serially linked to each other to form a foldable arm. The hinged segments [22a, b, c] are configured for transmission of rotational motion between each other. At least one of the hinged segments comprises at least one stage of a first speed increasing transmission. A first end [24] of the air exchange backup unit is swiveably attached to an electric motor [42] driving a blower [40]. And a second end [26] of the air exchange backup unit carries a detachable hand crank [28]. Manual rotation of the hand crank [28] rotates a shaft of the electric motor [42] at substantially a rated speed of the electric motor.

Abstract: A floor-space saving NBC filtration system for collective protection shelters with NBC filter unit and means for changing the NBC filtration system state between a ventilation mode, effective during normal times or conventional hazard, and a NBC protection mode, effective during NBC hazard. The NBC filtration system is contained in a space out of a comfortable reach of the shelter occupants thus saving usable floor-space. The means for changing the NBC filtration system state is operated from a location within the comfortable reach of the shelter occupants. The NBC filter unit inlet and outlet are located at close proximity to each other, a pre-filter outlet is located in proximity to the NBC filter unit inlet and outlet with a changeover valve, serving as means for changing the NBC filtration system state, located there between. Resulting in simple operation and space saving by the changeover valve replacing prior art space consuming flexible pipes.

Abstract: An air filter for heavy dust conditions has an efficient scavenging system. The air filter includes: a housing, a permeable filter, and a scavenger system. The scavenger system disposes of particles collected on the upstream surface of the permeable filter. The scavenger system includes: an air suction source, and a shutter. The shutter is positioned substantially along, typically below, the permeable filter, at a certain distance from a wall, typically the bottom wall, of the housing. The air suction source draws air from a collecting space located between the shutter and the wall of the housing. The shutter is being selectively operated to permit or restrict passage there-through. The air suction source efficiently operates to scavenge particles from the collecting space when the passage through the shutter is at least partially restricted.

Abstract: An engine air filter for heavy dust conditions such as used in heavy military and off-road vehicles, including a scavenging system, and a method of operation thereof. The air filter includes: a housing, a precleaner, a permeable filter, and a scavenger system. The scavenger system disposes of particles collected at the precleaner and on the upstream surface of the permeable filter. The scavenger system includes: an air suction source and a three way valve. The three way valve is airflow coupled to the precleaner, to the permeable filter and to the air suction source. The three way valve enables scavenging of the precleaner and the permeable filter alternately. Optionally, the air filter may further includes a pulse jet back-flow flush system.

Abstract: A floor-space saving NBC filtration system for collective protection shelters with NBC filter unit and means for changing the NBC filtration system state between a ventilation mode, effective during normal times or conventional hazard, and a NBC protection mode, effective during NBC hazard. The NBC filtration system is contained in a space out of a comfortable reach of the shelter occupants thus saving usable floor-space. The means for changing the NBC filtration system state is operated from a location within the comfortable reach of the shelter occupants. The NBC filter unit inlet and outlet are located at close proximity to each other, a pre-filter outlet is located in proximity to the NBC filter unit inlet and outlet with a changeover valve, serving as means for changing the NBC filtration system state, located there between. Resulting in simple operation and space saving by the changeover valve replacing prior art space consuming flexible pipes.

Abstract: A louver type blast valve making use of an aerodynamically configured blade, independently activated by air flow to block a blast shock wave and a subsequent return suction wave. The blast valve (FIG. 6) including a frame and at least one aerodynamically configured blade, independently activated by air flow to block a blast shock and a potentially following return wave. The aerodynamically configured blade having an elongated shape, including at least a steep convex surface and a flat or shallow concave surface, forming a leading edge and a trailing edge at the intersection of the surfaces. The blade being hinged to the frame about a longitudinal axis passing between the steep convex surface and the flat or shallow concave surface.

Abstract: A combined building air-conditioning unit and NBC protection system, containing an enclosed space housing a building air-conditioning unit and further including a plurality of chambers, a first chamber having an ambient air inlet port, one prefilter and a blower for sucking air through the prefilter, a second chamber having a valve including an open and closed state, receiving air from the blower and accommodating a C-detector and a valve actuator responsible, at least indirectly to, and operable by, the C-detector, and a third chamber housing at least one C-filter and a blower for sucking air from the second chamber via the C-filter into the building when the valve is in its closed state. A method for economically controlling air purity within a protected space is also provided.

Abstract: The invention provides a flap valve for controlling the air pressure within a protected space defined by walls, the flap valve having a valve flap, articulated at least indirectly to the surface of one of the walls and being subjectable to both a sealing force which forces the valve flap against a valve seat surrounding an opening in the wall surface and to an opening force which lifts the flap off the valve seat. The flap valve has a first position in which the protected space is sealed off from a contaminated environment, and a second position in which air from the protected space is allowed to escape into the environment via the opening, wherein the sealing force is a magnetic attraction between a portion of the surface of the valve flap and the valve seat. A method for controlling the air pressure within a protected space is also provided.

Abstract: The invention provides an NBC protection and decontamination system, having a space delimited by an enclosure, the enclosure having a clean air inlet port and an air outlet, a decontamination unit attachable to the outside of the enclosure, the decontamination unit having a plenum and a chamber separated from the plenum by an air flow laminator. The system also includes at least one air inlet valve communicating with the air outlet of the enclosure and leading to the plenum and to at least one air exhaust valve made in the chamber, spaced apart from the air inlet valve. An opening is provided for controlled passage between the enclosure and the decontamination unit, and also an opening in the decontamination unit, for controlling the passage between the unit and the outside. There is also provided an NBC protection and contamination method.

Abstract: The invention provides an NBC protection and decontamination system, having a space delimited by an enclosure, the enclosure having a clean air inlet port and an air outlet, a decontamination unit attachable to the outside of the enclosure, the decontamination unit having a plenum and a chamber separated from the plenum by an air flow laminator. The system also includes at least one air inlet valve communicating with the air outlet of the enclosure and leading to the plenum and to at least one air exhaust valve made in the chamber, spaced apart from the air inlet valve. An opening is provided for controlled passage between the enclosure and the decontamination unit, and also an opening in the decontamination unit, for controlling the passage between the unit and the outside. There is also provided an NBC protection and contamination method.

Abstract: The invention provides a flap valve for controlling the air pressure within a protected space defined by walls, the flap valve having a valve flap, articulated at least indirectly to the surface of one of the walls and being subjectable to both a sealing force which forces the valve flap against a valve seat surrounding an opening in the wall surface and to an opening force which lifts the flap off the valve seat. The flap valve has a first position in which the protected space is sealed off from a contaminated environment, and a second position in which air from the protected space is allowed to escape into the environment via the opening, wherein the sealing force is a magnetic attraction between a portion of the surface of the valve flap and the valve seat. A method for controlling the air pressure within a protected space is also provided.

Abstract: The invention provides a combined building air-conditioning unit and NBC protection system, containing an enclosed space housing a building air-conditioning unit and further including a plurality of chambers, a first chamber having an ambient air inlet port, one prefilter and a blower for sucking air through the prefilter, a second chamber having valve means including an open and closed state, receiving air from the blower and accommodating a C-detector and a valve means actuator, responsive, at least indirectly to, and operable by, the C-detector, and a third chamber housing at least one C-filter and a blower for sucking air from the second chamber via the C-filter into the building when the valve means is in its closed state. A method for economically controlling air purity within a protected space is also provided.

Abstract: The invention provides a sealable lead-through system for a protected space defined by walls, the system including at least one sleeve made of a flexible material, one end of the sleeve being tightly attached to the outside of one of the walls, at least one sealing element, approximately fitting the sleeve and being made of a material deformable in compression, the sealing element being provided with a bore approximately fitting the size of a transfer member intended to be led from outside the protected space into its interior or vice-versa, the sealing element being adapted to be subjected to a compressive force, for sealing off any interspaces between the transfer member and the bore, and between the sealing element and the sleeve.