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 manhole cover assembly includes a manhole cover supportable by a manhole frame. The manhole cover defines a latch bore having a longitudinal axis. A latch housing extends from the manhole cover, and a latch assembly is positioned at least partially therein. A first end of a latch yoke extends through the latch bore and slidably couples the latch yoke to the manhole cover along the longitudinal axis. A latch member is rotatably coupled to the second end of the latch yoke about a first transverse axis perpendicular to the longitudinal axis. The latch member is also rotatably coupled to the latch housing about a second transverse axis spaced from the first transverse axis. The latch member is selectively rotatable relative to the latch housing about the second transverse axis, between a locked position and an unlocked position, via sliding the latch yoke relative to the manhole cover.

Abstract: To improve assembly precision of a fuel cell by improving a sealing property. A first gasket 12 is integrally formed with a first gas diffusion layer 11 and a second gasket 14 is integrally formed with a second gas diffusion layer 13, and a hinge portion 15 connects the first gasket 12 to the second gasket 14. The gas diffusion layer incorporated gasket sandwiches a membrane-electrode from both sides in the thickness direction. A seal protrusion 12c is formed in a surface of the first gasket 12 or the second gasket 14 and comes into close contact with the membrane-electrode.

Abstract: A fresh airflow is conducted from a supply air chamber through nozzles into a ring-shaped mixing chamber. A circulated airflow is conducted from a room space into a cylindrical suction chamber inside a ring-shaped heat exchanger. From the suction chamber the circulated airflow travels through the heat exchanger into the mixing chamber. The nozzles are located in the upper part of the mixing chamber at a distance from each other on the periphery of at least one circle, whereby the mid-point of the circle is located on the vertical central axis of the supply air terminal device. The horizontal component of the direction vector of the fresh airflow discharging from each nozzle forms an angle ?, which is in a range of 45-135 degrees, with the radius of said at least one circle, and the direction vector is directed downward, in relation to the horizontal plane at an angle ?, which is in a range of 15-75 degrees, whereby a rotating airflow directed downward is formed in the mixing chamber.

Abstract: A blast wave damper comprises a section of duct, with a multiplicity of rigid elements each extending across the duct. All the elements are parallel to each other, and they are arranged in an array consisting of a multiplicity of lines, each such line extending across the duct. The elements in one line are staggered relative to the elements in an adjacent line, and the gaps between successive elements within a line are no wider than the widths of the elements. There may be ten columns of tubular elements in a regular array. This may be combined with a louver mechanism arranged to shut if the pressure drop exceeds a threshold.

Abstract: A ductwork system including a duct having a plurality of ducting panels joined together to define a flow passage extending therethrough, and the duct having structure for resisting damage thereto caused by a detonation within the duct. The structure for resisting damage can include an internal bracing within and extending across the flow passage of the duct to tie at least two sides of the duct together. For example, the internal bracing can be a reinforcement panel including a mounting frame with one or more elongated members extending from one side of the frame attached to a ducting panel to another side of the frame attached to an opposite ducting panel. Alternatively or in addition to the above structure, the duct can have structure for resisting damage that includes providing the duct with at least one curved or faceted side along an axial length of the duct.

Abstract: Explosion vent apparatus is provided, which includes a vent support unit defining a vent opening adapted to be aligned with an area to be protected from an overpressure condition, a vent panel movably mounted on the support unit in a normal closed position blocking the outlet and movable through a first displacement away from its closed position to a first overpressure-relieving position upon application of an overpressure of one magnitude of pressure while allowing movement of the vent panel through a second and greater displacement to a second overpressure-relieving position upon application of a higher overpressure. The vent panel does not deform or rupture upon opening, and recloses after pressure relief, either under spring pressure when opened under a lower first pressure, or by a fluid actuated reclosing mechanism upon full opening of the vent panel under a higher second pressure.

Abstract: A blast wave damper comprises a section of duct (14), with a multiplicity of rigid elements (18) each extending across the duct. All the elements are parallel to each other, and they are arranged in an array consisting of a multiplicity of lines, each such line extending across the duct (14). The elements in one line are staggered relative to the elements in an adjacent line, and the gaps between successive elements within a line are no wider than the widths of the elements. There may be ten columns of tubular elements in a regular array. This may be combined with a louvre mechanism (20) arranged to shut if the pressure drop exceeds a threshold.

Abstract: A ductwork system including a duct having a plurality of ducting panels joined together to define a flow passage extending therethrough, and the duct having structure for resisting damage thereto caused by a detonation within the duct. The structure for resisting damage can include an internal bracing within and extending across the flow passage of the duct to tie at least two sides of the duct together. For example, the internal bracing can be a reinforcement panel including a mounting frame with one or more elongated members extending from one side of the frame attached to a ducting panel to another side of the frame attached to an opposite ducting panel. Alternatively or in addition to the above structure, the duct can have structure for resisting damage that includes providing the duct with at least one curved or faceted side along an axial length of the duct.

Abstract: A louvre-type airflow regulator (10) for a mine passage comprises a plurality of louvre blades (12, 14, 16). Each blade is adapted for mounting in a frame (20). Each blade can pivot in the frame around a lengthwise axis between a predetermined position in which the louvre blades combine to close or restrict at least a portion of the passage, and an open position in which air is able to readily flow between the louvre blades and through the passage. A biasing mechanism is provided for acting on each louvre blade such that, in use, each louvre blade can be maintained in the predetermined position until a predetermined airflow against the louvre blades is reached.

Abstract: A flame front diverter element is designed to cause a minimal pressure drop under normal venting conditions when process vapors need to pass through the explosion protection system and to other equipment connected to the manifold system. In the event of a deflagration, the flame front diverter directs the high-speed pressure wave towards a bi-directional rupturable disc causing the rupturable disc to open thus creating an aspiration effect on the opposite bi-directional rupturable disc.

Abstract: An explosion protection venting system has a plurality of vessels or reactors connected by a common vent line. A flame front diverter having a pair of opposing rupturable discs is connected to each one of a plurality of vessels for directing a deflagration away from the normal flow path and through an alternate path that prevents damage to nearby structure.

Abstract: An electrical switchgear (ES) comprising at least one function module (FM, FM . . . ) having an encapsulated housing, and a decompression channel (DK) which is connected to the housing. Said decompression channel (DK) comprises a ventilation device (LV, LV . . . ) in at least one of its generated surfaces, said device having two wall-type ventilation elements (LE 1,2) which are successively arranged at a distance from each other and are provided with ventilation openings. One ventilation element (LE 1) is connected to the generated surface of the decompression channel (DK) in a fixed manner, and the other ventilation element (LE 2) can be moved in a guided manner against the fixed ventilation element (LE 1). The moveable ventilation element (LE 2) can be linearly displaced inside a guiding frame (FR) and the ventilation openings of the ventilation elements (LE 1,2) are staggered in relation to each other.

Abstract: A ceiling vent to reduce the temperature in a room that is subject to becoming uncomfortably hot. The vent contains two concentric tubes, one movable and the other stationary. The movable tube is attached to a damper plate so that when the movable tube is lowered, the vent opens. Attached to the stationary tube is a plastic fuse pin in a metal sleeve that engages a notch in the stepped upper portion of the movable tube. There is a spring attached at one end to the metal sleeve and at the other end to the damper plate. When the vent is opened, the spring is stretched. Should there be a fire in the room being vented, hot air rising through the vent would cause the plastic fuse pin to soften or melt, which would cause the plastic fuse pin to disengage from a notch and allow the spring to resume its rest position and close the vent.

Abstract: In many storms, high-wind velocity can cause severe damage to building structures by virtue of differential pressures caused by high-wind velocity winds traversing the structure, creating differential inside-outside pressures. Extremely low pressure on the downwind side of the structure causing higher internal pressures inside the structure to lift the roof or burst out windows and the like on the downwind side of the structure. The destructive effects of high-velocity winds on building structures are avoided by providing the building with controlled openings on the various surfaces of the building. Air pressure sensing devices sense pressure differentials caused by high-velocity winds on the upwind and downwind sides of the building and controlling the pressure control opening such that the high-pressure surface opening is closed and the low-pressure surface control opening is opened.

Abstract: A family of passive attenuators for shelter protection against explosions which reduce the pressure and impulse by combined effects of reflection, expansion, contraction and deviation contributed by the geometry of the attenuator.

Abstract: An apparatus for relieving overpressure conditions in the passenger compartment of a motor vehicle comprises a valve assembly that is mounted in an opening formed in an exterior wall of the compartment, the assembly includes a frame panel sized to fill the opening and having a passage formed therethrough to define an exhaust from the interior of the compartment to the exterior ambient space. Flap valve elements overlying the exhaust for allowing free flow of air in a direction from the interior of the compartment to the exterior while preventing air flow in the opposite direction. Overpressure relief support connectors mount the frame panel in the opening in the wall and are adapted to release the frame panel from its mounted position whenever the air pressure within the compartment exceeds a predetermined minimum level about atmospheric pressure.

Abstract: A ventilation control device for a high-speed train carriage is operable in conjunction with a ventilating blower. A deflectable spring flap is mounted to extend across the ventilation duct in the air flow path. When deflection of the flap reaches a threshold level corresponding to possible passenger discomfort, the flap operates a limit switch positioned behind it. This activates a driving solenoid to close a shutter which shuts off the flow through the duct. A timer holds the shutter closed for a predetermined period, after which it is re-opened. Use of a microprocessor-controlled continuous sensor and damper can thereby be avoided, while cutting out very large pressure fluctuations.

Abstract: This invention relates to a passive explosion protection device wherein a quick acting gate valve is designed in combination with means for directing and reflecting incumbent pressure surges to reduce or decelerate the surges prior to contact with the gate valve.

Abstract: A passive building vent disposed in an outside vertical building wall, communicates between the outside atmospheric air and the confined air within the building, via a housing forming an air mixing chamber with a passageway disposed therethrough. A movable membrane is mounted within the housing at one end of the passageway, the other end of the passageway communicates with the confined air and is disposed outside of the vertical building wall. The membrane has a closed position, substantially blocking the passageway and an open position, permitting the free flow of air therethrough. The air passage permits the flow of outside air into the air mixing chamber. A venting device communicates with the air mixing chamber permitting the flow of air to exit from the air mixing chamber. A deflector is mounted on the housing proximate the venting device and communicates with the air mixing chamber.