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EP2910284A2 - Valve closure mechanism and an air blast valve using said valve closure mechanism - Google Patents

Valve closure mechanism and an air blast valve using said valve closure mechanism Download PDF

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Publication number
EP2910284A2
EP2910284A2 EP15152126.7A EP15152126A EP2910284A2 EP 2910284 A2 EP2910284 A2 EP 2910284A2 EP 15152126 A EP15152126 A EP 15152126A EP 2910284 A2 EP2910284 A2 EP 2910284A2
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EP
European Patent Office
Prior art keywords
valve
perforations
plate
moveable
elements
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP15152126.7A
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German (de)
English (en)
French (fr)
Inventor
Jonathan Schneider
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beth El Zikhron Yaaqov Industries Ltd
Original Assignee
Beth El Zikhron Yaaqov Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Beth El Zikhron Yaaqov Industries Ltd filed Critical Beth El Zikhron Yaaqov Industries Ltd
Publication of EP2910284A2 publication Critical patent/EP2910284A2/en
Withdrawn legal-status Critical Current

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    • A—HUMAN NECESSITIES
    • A62—LIFE-SAVING; FIRE-FIGHTING
    • A62C—FIRE-FIGHTING
    • A62C4/00—Flame traps allowing passage of gas but not of flame or explosion wave

Definitions

  • This invention relates generally to air blast protection systems and particularly to air blast protection valves for use with such systems.
  • blast protection valves In order to protect against blasts, air entry and exit openings are fitted with blast protection valves that are able to protect against the most extreme situation. These provide effective protection for people and equipment against the impact of explosions caused during warfare or civil emergencies, including protection during repeated occurrences of both phases of the blast wave: the positive pressure phase and the negative suction phase.
  • the valve has a closure element typically having the general shape of a convex plate that is designed to block the vast majority of the blast wave from entering the protected space and from drawing crucial amounts of air out of the protected space.
  • the closure element is adapted to engage suitable valve seats within the housing on both sides, i.e. upstream and downstream, of the closure element.
  • the valve housing typically forms a channel for the air entering the protected space.
  • the moving air passes between the blast valve plate and the valve housing.
  • the high acceleration of the blast wave impacts the blast plate at high force and causes the closure of the air passage within milliseconds or fractions of milliseconds.
  • the valve closure element may be designed as a flat plate, or as a structured plate for example spherical or semi-spherical or hybrids of such shapes, with an annular air gap surrounding the valve closure element and typically concentric therewith.
  • the valve closure element has to be very strong to absorb the blast energy without deformation, while nevertheless having small mass in order to reduce inertia and allow short closing times.
  • the closure element is mounted for axial movement along the longitudinal axis of the valve so as to allow free passage of air at rated airflows with a minimum of air resistance, while closing the air passage extremely fast in case of a blast wave.
  • This mounting is achieved by elastic elements that allow the closure element to reach the valve seats upstream and downstream and return to the initial position, so as to be ready to take the next blast, without damage or fatigue for all elements of the system.
  • the elastic elements are springs, such as compressing springs or tension springs or a combination of both types of spring.
  • the elastic elements are typically mounted upstream or downstream the closure element or around the periphery thereof. In such case, these elements are themselves subject to the direct or indirect impact of the blast wave. This is undesirable for two reasons. First, the air blast can damage or cause stress to the elastic elements; and secondly, the elastic elements obstruct the air stream and can increase the pressure loss.
  • Fig. 1 illustrates the general design of a shelter protected from blast waves and air contamination.
  • At the air intake is one or many blast protection valves 1 installed through the wall. Incoming air into the shelter can come only through these valves.
  • the air flow is drawn through piping 2 to air purification filters 3 that release filtered air through ducting 4 to a blower 5, which pressurizes the protected space within the shelter.
  • An air exit valve 6 regulates the air over-pressure in the protected space to a desired pressure; and it likewise is of the form of a wall-mounted device similar to the blast protection valves 1.
  • Figs. 2 to 5 show a conventional blast protection valve.
  • Air enters via an entry aperture 8 into a housing 9 having an exit aperture 10 and flows through an annular gap between the housing 9 and a valve plate 12 (constituting a closure element). Air flows inside the housing around the periphery of the blast valve plate 12 to the exit aperture 10.
  • the valve plate 12 is resiliently displaceable within the air stream via tension springs 11 one end of which is attached to a periphery of the valve plate 12 and the opposite end of which is anchored to an internal side wall the housing 9.
  • the springs 11 partially obstruct air-flow, thus increasing the pressure drop across the valve and reducing its efficiency.
  • the very high impact of the air blast acts directly on the side-wall of the springs 11, such that repeated operation of the valve causes damage to the valve, such as distortion and reduces its elasticity.
  • Air ventilation or air filtration systems employing air blast protection valves are designed to provide a defined amount of airflow to a protected space according to a given standard. Total air throughput dictates the number of valves of given rating required. Larger valves are able to handle a higher air-flow and therefore allow the rated air-flow to be handled using fewer valves.
  • Non-return valves having a generally tubular valve body that includes an elongate passageway with inlet and outlet at opposing ends.
  • a valve membrane is of a generally conical-shaped diaphragm formed integrally with the valve body and the diaphragm has a collapsible opening or aperture located at or adjacent the cones apex.
  • WO 1999/027283 discloses a safety valve comprising a guide body provided with an axial perforation and a valve body, movable inside the perforation.
  • the valve body has a frustoconical head able to bear against the walls of a conical middle section of said axial perforation.
  • the valve body is movable axially under the action, on the one hand, of the pressure of the inflating air and, on the other hand, of pressure means.
  • CA 2,238,593 discloses an inflating valve that includes inner and outer pieces which have first and second peripheral flanges for cementing together and a central plug and a central tubular spout to be sealingly fitted together.
  • a frusto-conical shaped first web portion is formed between the plug and the first peripheral flange to project inward from the first peripheral flange and is provided with a plurality of passage holes for communication with the tubular spout.
  • a second web portion of frusto-conical shape is formed between the tubular spout and the second peripheral flange to abut against the first peripheral flange and can be flexed at its wider end so as to separate the tubular spout from the plug.
  • this valve has a pair of interacting conical valve elements, but they are disposed with their respective flanges abutting each other and their apices mutually opposed similar to the arrangement shown in Fig. 2 . They are not disposed one inside the other.
  • valves having conical seating are well-known as are valves having conical sealing elements or diaphragms that may be resiliently urged toward the conical seating in order to seal the air passage between the seating and the diaphragm.
  • a valve mechanism particularly for a gas valve, having at least one pair of axially displaceable perforated plates having perforations that are mutually offset, so that when the two plates abut one another the perforations in each plate are sealed by the complementary abutting plate.
  • US Patent No. 7,527,663 discloses a ventilation system providing NBC protection for a shelter with constant slight excess pressure, having an air inlet and outlet and an explosion protection valve.
  • a pre-filter is disposed between two rigid plates that have mutually offset perforations, one of which is moveable toward the other under the force of an explosion. When the two plates are mutually apart, air can flow through the perforations of both plates but under the force of an explosion, the perforations in each plate are sealed by the opposing plate owing to the fact that the respective perforations in both plates are non-overlapping.
  • valve mechanism for an air blast valve having a pair of fixed outer perforated closure elements rigidly supported within a housing and defining a respective inlet and outlet of the valve; and at least one intermediate perforated closure element resiliently supported between the fixed elements and adapted for axial movement therebetween.
  • a further object is to provide an air exit valve with the ability to regulate the overpressure within a space.
  • An air blast valve utilizes a set of three perforated conical elements that are stacked one inside the other, such that the two outermost conical elements are in permanently fixed positions and the intermediate element has lower mass and is axially and/or radially moveable relative to both of the outer plates and capable of retention in defined working positions between the outermost elements by resilient elements.
  • the holes of the perforated cones are arranged in such a way that depending on the mutual alignment between the cones they can allow air passage or block air passage. If the intermediate element abuts either of the fixed elements, the air passage is blocked, while in a neutral position of the intermediate element where it is axially separated from both of the fixed elements, air can pass from the inlet to the outlet of the valve with pressure drops of less than 500 Pa.
  • the pressure drops can be adjusted e.g. to 135 Pa or 300 Pa meeting the requirements of particular standards or needs.
  • the rigidity of the middle cone may be reduced owing to the fact that the travelling distances between working (i.e. open) position and closed position are so small that the force applied thereto by the high acceleration forces of the blast wave is not sufficiently high to deform the intermediate cone during the stopping process. This arises from several factors that work simultaneously toward the same effect:
  • Fig. 6a shows pictorially a detail of an air blast protection valve 20 mounted on a sleeve 21 in the shelter wall 22.
  • the sleeve 21 is an anchored pipe passing through the shelter wall and having a flange on which the valve is mounted.
  • the sleeve is shown in Fig. 1 , only an edge thereof being visible in Figs. 6a and 6b.
  • Fig. 6b shows a corresponding air entry valve where the valve is mounted in opposite orientation.
  • the valve has a sufficiently narrow profile that it can be completely accommodated within the thickness of the wall without any overhang into the shelter thus saving space. This is one of the benefits of the invention.
  • Figs. 7 to 10c show an air blast valve 25 that may be dimensioned for mounting on the flange of a standard 8-inch wall sleeve and has an air outlet capacity of 800 m 3 /h.
  • the valve 25 includes a pair of rigid perforated fixed elements 26 and 27 defining a respective inlet and outlet of the valve, and an intermediate perforated closure element 28 resiliently supported for axial movement between the fixed elements.
  • the intermediate perforated closure element is formed of plate material that is resistant to corrosion and temperature and has a thickness between 0.5 and 3 mm.
  • the fixed elements 26, 27 and the intermediate closure element 28 are generally concave in shape and have similar cross-sectional profiles so that the intermediate closure element 28 may be urged into tight abutting contact with either of the rigid fixed elements. Specifically, in one position as shown in Figs. 10a and 11a , an inner concave surface of the intermediate closure element 28 abuts an outer convex surface of one of the rigid elements; while in the other position as shown in Figs. 10c and 11c , an outer convex surface of the intermediate closure element 28 abuts an inner concave surface of the other rigid element.
  • the intermediate closure element 28 has perforations 30 that are mutually offset relative to perforations 31 in both of the fixed elements so that when the intermediate closure element is subjected to an air blast whereby it is urged into abutting contact with either one of the fixed elements, the respective perforations in the fixed element and in the abutting intermediate closure element are mutually sealed thereby preventing air flow, while when the intermediate closure element is axially separated from both of the fixed elements, air can pass between the inlet and the outlet.
  • a spring 32 constituting a resilient biasing element is coupled to the intermediate closure element for maintaining the at least one intermediate closure element in an axially displaced position from both of the fixed elements in an open position of the valve shown in Figs. 10b and 11b .
  • An air blast in either direction forces the intermediate closure element 28 against the resilient bias force of the spring 32 thus urging it into abutting contact with the respective downstream fixed element, thereby sealing the valve and preventing air flow.
  • air blasts have two mutually opposite intake and exhaust phases whereby in short successive the intermediate closure element is urged against both of the fixed elements, in both cases preventing passage of air through the valve and thus blocking the air blast from permeating into the shelter.
  • 10d is an enlarged partial sectional view of the valve when used as an air exit valve.
  • the intermediate closure element 28 is slightly displaced from the outermost fixed element 26 so that the valve is slightly open and releases air from the shelter at a lower pressure than the air inlet pressure. This creates a slight over-pressure in the shelter that prevents contaminants in the atmosphere outside the shelter from entering the shelter.
  • the opening can be assisted by gravity whereby the middle plate can move into the intermediate position at least partly under its own weight. It will be borne in mind that this occurs only when the pressure of the air blast has diminished and it becomes safe for the valve to re-open. Since there is no longer high air pressure acting against the spring, the spring is free to return to its equilibrium position where the middle plate is intermediate the two outer plates. The weight of the middle plate may assist this process.
  • Figs. 12d, 12e and 12f show details of a valve 25 according to such an embodiment having a casing 29 open at one end and supporting a flexible closure member 28 that operates under gravity alone.
  • the valve 25 includes a pair of rigid perforated fixed elements 26 and 27 defining a respective inlet and outlet of the valve as shown by the arrows.
  • the inlet element 26 is part of the casing 29.
  • the closure member 28 may be a perforated rubber flap or diaphragm that is hingedly attached at one edge to an inside edge of the casing intermediate the elements 26 and 27 so as to be capable of vertical pivotal movement between the fixed elements 26 and 27.
  • the closure member 28 When an air blast enters the valve through the fixed element 26 constituted by the wall of the casing, the closure member 28 is urged into abutting and sealing contact with the fixed element 27, the respective perforations in the fixed element 27 and in the abutting intermediate closure member 28 being mutually sealed thereby preventing air flow.
  • the closure element 28 In the negative suction phase of the air blast, the closure element 28 is urged into abutting contact with the fixed element 26 assisted in this case by gravity.
  • the intermediate closure member 28 In normal operating conditions, the intermediate closure member 28 is axially separated from both of the fixed elements, allowing air to pass between the inlet and the outlet.
  • the intermediate closure member 28 may be 2-8 mm in thickness and, in order to enhance the effect of gravity, it may be reinforced with a material of higher density than the plate itself such as metal fibers, wire or a perforated metal sheet, such as steel.
  • the intermediate closure member 28 does not itself need to be flexible so long as it is able to swing into sealing abutment with the fixed plates. So it could be formed of thin metal sheet having a thickness in excess of 1mm.
  • the intermediate closure member 28 can be formed of a single material or a sandwich structure.
  • the arrangement shown in Figs. 12d to 12f operates as a standalone module, several such modules can be cascaded in parallel for higher air flows within a unitary valve system.
  • the operating position is achieved mainly by gravity of the intermediate closure member 28 thereby providing the overpressure required by the locally applicable shelter standard.
  • the valve is used as air exit valve and should regulate the overpressure to 250 Pa.
  • stopper elements such as notches may be provided to keep the plate in a preferred position even if some fluctuations of the air flow occur. However in the blast situations they should neither increase the closure time nor reduce the closure effect and tightness of the seal.
  • valve elements were conical in shape with identical or nearly identical apex angles.
  • other hollow or concave cup-shaped cross-sections may be used.
  • the intermediate closure element 28 may be sufficiently flexible to adapt to the contour of the fixed elements 26, 27. This allows for the shape of the intermediate closure element 28 to be similar to that of the fixed elements, without being necessarily identical.
  • the intermediate closure element 28 may be rigid and shaped for abutting contact with the fixed elements. It should also be noted that only those portions of the surfaces of the intermediate closure element 28 and of the elements 26, 27 that either have perforations or serve to seal perforations of an abutting element need be complementary in shape.
  • the intermediate closure element 28 may have a downstream surface of generally spherical shape able to withstand a yield stress >150 MPa.
  • the two fixed elements 26 and 27 are provided with a peripheral flange 33 having through-holes 34 that allow the flange to be bolted to the wall sleeve.
  • a guide bolt 35 is fixedly supported at a first end by the outermost fixed element 26 using a nut 36 and a counter nut 37 and slidably supports the intermediate closure element 28 via a bearing 38.
  • FIG. 9 may be mounted on the guide bolt 35 to accommodate the spring 32 and extends through an aperture (not shown) in the innermost element 27 so as to allow axial displacement of the intermediate closure element 28 relative thereto.
  • An adjustable seat 40 is slidably supported on the guide bolt 35 and may be urged toward the first end thereof by tightening a nut 41 so as to adjust the tension in the spring 32, which is supported by the adjustable seat 40 and secured by a bolt 42. This sets the resilient bias force in the equilibrium position shown in Fig. 10b when the intermediate closure element 28 abuts neither of the fixed rigid elements 26, 27 thus allowing air to flow through the valve.
  • Fig. 10a shows a first closed position of the valve where an air blast enters at through the outermost element 26 at sufficiently high force to overcome the resilient bias force of the spring 32.
  • the resultant force acting on the intermediate closure element 28 urges it toward and into abutting contact with the innermost element 27, thus closing the valve and preventing the air blast from passing therethrough.
  • This action compresses the spring 26, which expands and releases the intermediate closure element 28 back to its equilibrium open position when the force of the air blast dissipates.
  • Fig. 10c shows the opposite situation where the exhaust phase of the valve acting in the opposite direction flows initially through the perforations in the innermost element 27 and urges the intermediate closure element 28 toward and into abutting contact with the outermost element 26, thus closing the valve and preventing the air blast from passing therethrough.
  • This action also stretches the spring 32 as shown in Fig. 10c , which compresses and releases the intermediate closure element 28 back to its equilibrium open position when the force of the air blast dissipates. Movement of the intermediate closure element 28 in either direction induces axial displacement of the spring housing 39 through the aperture in the innermost element 27, thus allowing the intermediate closure element 28 to reach the full extent of its stroke, which is preferably less than ⁇ 10 mm.
  • the spring 32 is supported between the closed end of the spring housing 39 and the adjustable seat, which is anchored to the guide bolt 35 towards it second end, remote from the outermost element 26.
  • the spring 32 in this case compresses when the intermediate closure element 28 is urged by the air blast toward the innermost element 27 and stretches when it is urged by the air blast toward the outermost element 26.
  • the equilibrium position is adjusted so that the intermediate closure element 28 is clear of both the fixed elements.
  • the intermediate closure element 28 is preferably, substantially mid-way between the two in the equilibrium position so that it closes the valve when subjected to a similar closure force in either direction, while maintaining substantially equal closure times.
  • the intermediate closure element 28 When the valve is used an air exit valve, the intermediate closure element 28 is much closer in the equilibrium position to the outermost element 26 as shown in Figs. 10d .
  • the distance between the two rigid fixed elements 26, 27 is small, typically about 11 mm, so that the required axial displacement of the intermediate closure element 28 to close the valve in either direction is so small that, when subjected to high acceleration by the air blast, it reaches abutting contact with the respective rigid element before the air blast is able to cause damage or distortion.
  • the total area of the perforations in each element exceeds significantly 50% of the open area of the connecting 8 inch wall sleeve.
  • the area of the opening of an 8-inch diameter wall sleeve is ⁇ . (4 ⁇ 25.4) 2 mm 2 i.e. about 32,530 mm 2 .
  • the sum of holes in each of the three elements 26, 27, 28 have an open area that is larger than 16,265 mm 2 .
  • the guide bolt 35 of the valve mechanism is shown attached to the outermost element 26 and extends into the hollow center of the valve, it can equally well be supported by the innermost element 27 and extend outward as shown in Fig. 9 .
  • the spring housing 39 extends through an aperture in the outermost element 26 and the spring 32 is supported between the closed end of the spring housing 39 and the adjustable seat, which is anchored to the guide bolt 35 towards it second end, in this case remote from the innermost element 26.
  • the spring 32 in this case stretches when the intermediate closure element 28 is urged by the air blast toward the innermost element 27 and compresses when it is urged by the air blast toward the outermost element 26.
  • spring 32 is shown as a single spring, there may be applications where owing to manufacturing tolerances and impact to sliding forces, more than one spring can be used with the effect that with preloaded springs having different stiffness coefficients the working points can be adjusted more easily and more stably.
  • Figs. 11a, 11b and 11c and 12a, 12b and 12c are partial sectional views of the valve elements in different operating positions showing air flow in both directions. These positions correspond to those shown and in Figs. 10a, 10b and 10c respectively.
  • Figs. 11a and 12a depict a first closed position where the closure element 28 is in abutting contact with the innermost fixed element 27.
  • Figs. 11b and 12c depict an open position where the closure element 28 is in its equilibrium position intermediate the two fixed elements 26 and 27 and
  • Figs. 11c and 12c depict a second closed position where the closure element 28 is in abutting contact with the outermost fixed element 26.
  • the air blast valve 25 is able to withstand blast waves with pressures of 1 to 70 bar and prevents air penetration into protected spaces to a leakage degree of 300 Pa ⁇ s or better.
  • Figs. 13a and 13b are partial sectional views of a valve 45 according to a second embodiment of the invention in the open position and Figs. 14a and 14b show similar views of the valve in the closed position.
  • the principle of the closure mechanism still relies on the displacement of two perforated plates 26, 28 that are relatively displaceable so that in the closed position of the valve, perforations in each plate are sealed by the complementary plate.
  • the moveable plate 28 is the side wall of an inner cylinder 46 (constituting a first element) that is coaxially disposed within an outer cylinder 47 (constituting a second element) whose side wall is the fixed plate 26, the respective side-walls of the two cylinders being in abutting contact.
  • the inner cylinder 46 is axially displaceable relative to the outer cylinder 47 against the bias force of a compression spring 32 that urges the inner cylinder 46 into a position where its perforations 30 are aligned with the perforations 31 in the outer cylinder 47 such that the respective perforations overlap thereby allowing air to flow through both perforations.
  • a leaf spring 50 is mounted internally on an end surface of the outer cylinder and acts as a buffer between the two cylinders. The air blast enter inlet apertures 51 at an end of the outer cylinder against the bias force of the spring 32, so as to displace the inner cylinder 46 to the position shown in Figs. 14a and 14b where the respective perforations 30 and 31 are in anti-phase, thus sealing the valve.
  • the plates 26 and 28 are in constant abutting relationship but their respective perforations are brought into and out of mutual alignment based on relative axial displacement of the two plates.
  • the moveable and fixed plates have an equal number of perforations 30 and 31 that are regularly spaced apart by the same interval spacing in order to ensure that in the open position all the perforations in both plates allow air to pass through. This requirement will not be realized if one plate has fewer perforations than the other. In any case, the perforations must be spaced and dimensioned so that in the closed position all the perforations in each plate are sealed by the complementary plate.
  • the two cylinders could also be configured to rotate relative to each other to the same effect.
  • two concentric cylinders may be articulated so that force acting linearly on the inner cylinder rotates it relative to the outer cylinder thereby bringing the perforations out of mutual alignment.
  • the requirement to transduce linear motion to rotation of the valve elements renders such an action less attractive for applications having stringent closure times.
  • the valve mechanism according to the invention may be used in other less stringent applications where increased operating times are less critical.
  • the air blast valve is shown in Fig. 6a as an air exit valve, it may equally well serve as the air inlet valve.
  • higher stringencies apply to the exit valve since, as will be understood to those versed in the art of safety shelters, the air pressure in the shelter must be maintained at slightly above atmospheric pressure in order to inhibit the entry of contaminated air. In practice, this requires that the air exit valve release air from the shelter at a lower rate than the air inlet admits fresh filtered air.
  • the moveable plate in any of its embodiments is used as an air exit valve in such a shelter as shown in Fig. 1 , the moveable plate must be biased so that in its equilibrium intermediate position it is closer to the downstream fixed plate than to the upstream fixed plate.
  • An air exit valve according to the invention meets the overpressure regulation at defined airflows, e.g. 300 Pa @ 800 m 3 /h and 135 Pa@ 300 m 3 /h as set by the Israel Standards Institute.
  • Figs. 15a, 15b and 15c are partial cross-sectional views showing details of an air blast valve 55 having a closure mechanism according to another embodiment also based on a pair of concentric cylinders, but which in this case are both fixed.
  • an inner cylinder 56 having perforations 31 is coaxially mounted within an outer cylinder 57 having perforations 31.
  • the two cylinders are dimensioned to leave an air gap 60 between the respective side-walls of the two cylinders.
  • the side-walls of the two cylinders are analogous to the two fixed rigid plates of the two embodiment described above with reference to Figs. 9-10 and 13-14 , respectively.
  • Figs. 9-10 and 13-14 are analogous to the two fixed rigid plates of the two embodiment described above with reference to Figs. 9-10 and 13-14 , respectively.
  • a moveable closure element Disposed in the air gap 60 between the two fixed cylinders 56 and 57 is a moveable closure element in the form of a tubular rubber diaphragm 58 that is likewise perforated, but whose perforations 30 are out of overlapping alignment with the perforations 31 of the inner and outer cylinders.
  • the diaphragm 58 In an equilibrium position of the valve, the diaphragm 58 is stretched taut intermediate the side-walls of the two fixed cylinders 56 and 57, thus allowing air passage via the perforations 31 of the two fixed cylinders and the perforations 30 of the moveable diaphragm 58.
  • the two cylinders 56 and 57 constitute fixed plates and the diaphragm 58, which in this case is pliable, is the moveable plate such that a closure force applied to the moveable plate brings it into abutting relationship with the fixed plates in an analogous manner to that described above with reference to Figs. 7-10 .
  • This embodiment has been described with regard to two rigid outer plates and a flexible inner plate.
  • the opposite may equally be employed where in one phase of the air blast a first flexible plate is urged into abutting contact with one side of a rigid plate while in the opposite phase of the air blast a second flexible plate is urged into abutting contact with the opposite side of the rigid plate.
  • Figs. 16a, 16b and 16c are partial cross-sectional schematic views of an air blast valve 65 having a closure mechanism according to a further embodiment, which is similar in principle to that shown in Figs.15a to 15c .
  • identical reference numerals are employed.
  • frusto-conical valve elements are used and the diaphragm is in the form of a frusto-conical cap that is disposed within the air gap 60 and is closed at its apex 66 so at to envelop the inner conical element 56.
  • the principle of operation is similar to that of Figs.15a to 15c in that the ends of the valve are sealed and air enters the perforations 30, 31 in the side walls.
  • the diaphragm 58 widens or contracts and this affects its length. Specifically, upon contracting inwardly as shown in Fig. 16b its length increases, while the widening of the diaphragm 58 as shown in Fig. 16c causes its length to decrease. This is not shown in Figs. 16a, 16a and 16c , which are merely schematic representations. However, it is shown in Figs. 17a, 17b and 17c from which it emerges that matching perforations 31 on the inner element 56 and the outer element 57 are not radially aligned since the location of the complementary perforations in the diaphragm move axially depending on the phase of the air blast.
  • the material is depicted by the white space and the perforations appear grey.
  • the perforations 30 in the diaphragm are axially displaced toward the apex 66 of the valve i.e. the left of the picture.
  • This is shown by cross-hatching the material bounding matching perforations 31 that are shown as unfilled rectangles in both pictures, it being seen that the perforation 31 of the outer cone 57 in Fig.
  • Figs. 18a and 18b are partial cross-sections through an air blast valve having an elongated diaphragm 58 formed of multiple segments of which there are shown two segments 70 and 71 mounted end to end. As best shown in Fig. 18b , each segment 70, 71 is supported at opposite ends by respective buttresses 75, 76 that are mounted between the opposing surfaces of the two fixed cylinders or cones 56, 57.
  • the buttresses 75, 76 may be formed of plastics by injection molding or other techniques and may be shaped as shown in Fig. 18b to provide interlocking contact. In the figure, only one buttress is shown for each segment since the opposite end of the segment is not shown in the figure.
  • Each diaphragm segment is thus simply supported at its ends like a bridge and is free to deflect upward and downward between its fixed end points. Obviously, even when fully deflected, the diaphragm segments 70, 71 cannot make abutting contact with the upper and lower surfaces of the two fixed cylinders or cones 56, 57 immediately proximate the buttresses 75, 76. This does not affect or impede the operation of the valve provided that there are no perforations in at least one of the diaphragm segment and the upper and lower fixed cylinders in those areas of incomplete abutting contact. For the sake of clarification, this will be explained with reference to two columns of perforations 31a and 31b in the upper cylinder 57 shown in Fig.
  • cylindrical or conical valve elements are used, it is reiterated that this is by way of example and other geometrical shapes may be used provided that they are coaxial and mutually aligned. They may, but need not, be axially symmetrical about a longitudinal axis.
  • the embodiment of Figs. 13 and 14 could employ coaxial polyhedral valve elements adapted for mutual sliding movement such that they fit exactly one inside the other with abutting contact.
  • the embodiments of Figs. 15 to 18 which are described with regard to cylindrical and conical valve elements may employ coaxial polyhedral valve elements.
  • corresponding diaphragms are preferably provided for each face of the polyhedron so as to render the valve substantially insensitive to the direction of the air blast. Nevertheless, depending on the number of faces in the polyhedron, some faces need not participate in the closure operation relying instead on the efficacy of adjacent faces and their respective diaphragms. In other words, if polyhedral elements are used, it is not essential that all faces be perforated.

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  • Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Business, Economics & Management (AREA)
  • Emergency Management (AREA)
  • Check Valves (AREA)
EP15152126.7A 2014-02-24 2015-01-22 Valve closure mechanism and an air blast valve using said valve closure mechanism Withdrawn EP2910284A2 (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
IL231140A IL231140A0 (he) 2014-02-24 2014-02-24 מנגנון סגירה לשסתום פיצוץ אוויר המשתמש במנגנון סגירה כאמור

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EP2910284A2 true EP2910284A2 (en) 2015-08-26

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EP15152126.7A Withdrawn EP2910284A2 (en) 2014-02-24 2015-01-22 Valve closure mechanism and an air blast valve using said valve closure mechanism

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EP (1) EP2910284A2 (he)
IL (1) IL231140A0 (he)
SG (1) SG10201500395UA (he)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110496337A (zh) * 2019-08-23 2019-11-26 徐州八方安全设备有限公司 一种阻火芯及使用该阻火芯的阻火元件

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2238593A1 (en) 1997-05-30 1998-11-30 Bulton Enterprises Co., Ltd. Inflating valve
WO1999027283A1 (en) 1997-11-26 1999-06-03 Terragni, Arnaldo Check valve for inflation of balls
US6824117B2 (en) 1999-06-15 2004-11-30 Ip. One Pty Ltd. Non-return valve
US7527663B2 (en) 2003-05-22 2009-05-05 Andair Ag Ventilation system providing NBC protection

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2238593A1 (en) 1997-05-30 1998-11-30 Bulton Enterprises Co., Ltd. Inflating valve
WO1999027283A1 (en) 1997-11-26 1999-06-03 Terragni, Arnaldo Check valve for inflation of balls
US6824117B2 (en) 1999-06-15 2004-11-30 Ip. One Pty Ltd. Non-return valve
US20060065316A1 (en) 1999-06-15 2006-03-30 Horton David R Non-return valve
US7527663B2 (en) 2003-05-22 2009-05-05 Andair Ag Ventilation system providing NBC protection

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
AIR BLAST PROTECTION VALVE, 28 February 2013 (2013-02-28)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110496337A (zh) * 2019-08-23 2019-11-26 徐州八方安全设备有限公司 一种阻火芯及使用该阻火芯的阻火元件

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