GB2278376A

GB2278376A - Pressure relief device for roof or wall

Info

Publication number: GB2278376A
Application number: GB9410613A
Authority: GB
Inventors: Dubravco Stojakovio
Original assignee: ABB Miljo Norsk Viftefabrikk AS
Current assignee: ABB Miljo Norsk Viftefabrikk AS
Priority date: 1993-05-28
Filing date: 1994-05-26
Publication date: 1994-11-30
Anticipated expiration: 2014-05-26
Also published as: NO931979L; NO931979D0; NO178116C; NO178116B; GB2278376B; GB9410613D0

Abstract

A pressure release device suitable for use in a roof or a wall is adapted to release sudden pressure increase inside or below the device and to capture falling objects. Panels (2) are hinged at one side and at the opposite side are clamped with a predetermined force, such that the panels open at a predetermined overpressure to release the pressure to the atmosphere, and doors (1) are hinged along one side inside each panel (2), abutting with their opposite side against the inside of the panel at an acute angle in such a way that the doors (1) open to an angle substantially parallel with the panels when an overpressure occurs inside, and that the panels and the doors are forced to rotate in the direction opposite to the opening direction when a falling object hits a panel (2), deforms the panel and forces the panel against the stepdoor. <IMAGE>

Description

"Pressure Release Device" The present invention relates to a pressure release device. The invention relates particularly to a pressure release device providing protection means from falling objects.

Pressure release devices installed in roofs, as well as pressure release panels installed in walls have as a main purpose very quickly and effectively to release a rapidly increasing interior overpressure to the atmosphere, especially as may be caused by explosions.

Such pressure release devices generally comprise panels which form parts of walls or roofs before they are activated in which case they open to release the overpressure.

By having such panels installed in roofs as well as in walls, danger exists when heavy objects are dropped and fall towards a roof or a wall. Such objects will, when falling on panels, destroy the panels and damage facilities below or inside the panels.

The present invention is to help ensure that dropped objects are intercepted by the pressure release device, thereby avoiding damage to equipment.

According to the present invention there is provided a pressure release device suitable for use in a roof or a wall, adapted to release sudden pressure increase inside or below the device and to capture falling objects, wherein panels are hinged at one side and at the opposite side are clamped with a predetermined force, such that the panels open at a predetermined overpressure to release the pressure to the atmosphere, characterised in that a number of stepdoors are hinged along one side inside each panel, abutting with their opposite side against the inside of the panel at an acute angle in such a way that the stepdoors open to an angle substantially parallel with the panels when an overpressure occurs inside, such as from an explosion, and that the panels and the stepdoors are forced to rotate in the direction opposite to the opening direction when a falling object hits a panel, deforms the panel and forces the panel against the stepdoor, the stepdoor and the panel thereby absorbing substantially all the kinetic energy from the object, thereby avoiding the falling object penetrating the panel and the stepdoor and damaging equipment below or behind the stepdoor.

Preferably, the free side of a stepdoor is forced downwardly when an object deforms or penetrates the corresponding panel, and there are provided energy absorbing members secured below the stepdoors which are thereby deformed or damaged, thereby absorbing the resident kinetic energy from the object. An embodiment of a pressure release device according to the present invention will now be described, by way of example, with reference to the accompanying drawings in which: Fig 1 is a schematic showing a pressure release device in use; Fig 2 is a schematic showing a pressure release device receiving a falling object; Fig 3 is a more detailed drawing of the pressure release device of 2E; Fig 4 is a detail of the pressure release device of Figs 1 and 2; Fig 5 is a detail of the pressure release device of Figs 1 and 2.

Referring to the drawings fig 1 discloses a schematic vertical section of a pressure release device according to the present invention, the figs 1A-D thereby disclosing the behaviour of the device based on sudden pressure increase below or inside the panels. Figs 2A E disclose correspondingly the behaviour of the panel in a situation where a heavy object falls towards the panel and fig 3 discloses, enlarged and schematically, a stepdoor type panel in its normal position, abutting against the panel.

As disclosed in fig lA, the pressure release device principally comprises sections having panels 2 in walls or roofs, which panels may be rotated in case a sudden increase in the pressure should occur on one side of the panel, such as would be caused be an explosion.

Such panels often are used in places where a danger exists that objects may fall onto the panels. Such objects frequently are very heavy, they therefore without doubt in many cases would penetrate the panels and damage facilities or equipment below or inside the panels.

To avoid this, a number of stepdoors 1 are arranged close to each other below (or behind) the panels 2, abutting against the inside of the panels 2. The upper edges of the stepdoors follow possible movements of the panels 2 and adjust substantially parallel with the panels 2 when these are rotated in situations where overpressure is to be given free passage past the stepdoors 1, as disclosed in fig 1D. The stepdoors 1 thereby are rotated in hinges 5 and the panels 2 are rotated in hinges 7.

Fig 2 discloses one situation where an object 4 falls down towards the horizontal panel 2 and where stepdoors 1 are abutting against the underside of the panels 2.

When an object 4 hits a panel 2 the panel will be deformed and the underlying stepdoor 1 will be pressed downwardly. (In cases where the panels and the stepdoors are installed vertically, the stepdoors 1 inside the panels will be pressed inwardly).

Figs 2D and E further disclose how the object 3 is captured by the panel 2 and the underlying stepdoors 1.

The panels 2 and the stepdoors 1 thereby intercept the potential energy of the object 4 by deformation and will stop the movement of the object.

The purpose of the present invention is to capture and intercept falling or dropped objects 4 thereby avoiding damage to equipment below or inside the panels.

Penetration of the panels 2 and even the stepdoors 1 may be acceptable if underlying equipment or inside equipment is not damaged.

Principally the pressure release device according to the present invention is used for pressure release in horizontal positions, eg as floors or roofs and also in a vertical position as walls.

Substantially all the energy of from a falling object 4 is taken up by the panels and the stepdoors, whereby is effectively stopped. Angle members 6 (of L-shaped cross sections) are arranged abutting against the underside or inside of the stepdoors. Falling objects 4 hitting the stepdoors 1 will force the stepdoors towards the corresponding angle members 6 which, together with the stepdoors 1, take up substantially all the kinetic energy by deforming or even breaking.

This is further disclosed in fig 4 as an enlargement of fig 2E.

Fig 5 is an end view of a part of the release device, showing a hinge 5 and angle member 6 corresponding to a single stepdoor 1.

Claims

1. A pressure release device suitable for use in a roof or a wall, adapted to release sudden pressure increase inside or below the device and to capture falling objects, wherein panels are hinged at one side and at the opposite side are clamped with a predetermined force, such that the panels open at a predetermined overpressure to release the pressure to the atmosphere, characterized in that a number of stepdoors (1) are hinged along one side inside each panel (2), abutting with their opposite side against the inside of the panel at an acute angle in such a way that the stepdoors (1) open to an angle substantially parallel with the panels when an overpressure occurs inside, such as from an explosion, and that the panels and the stepdoors are forced to rotate in the direction opposite to the opening direction when a falling object hits a panel (2), deforms the panel and forces the panel against the stepdoor, the stepdoor and the panel thereby absorbing substantially all the kinetic energy from the object, thereby avoiding the falling object penetrating the panel and the stepdoor and damaging equipment below or behind the stepdoor.

2. A pressure release device according to claim 1, characterized in that the free side of a stepdoor is forced downwardly when an object deforms or penetrates the corresponding panel, and there are provided energy absorbing members (6) secured below the stepdoors which are thereby deformed or damaged, thereby absorbing the resident kinetic energy from the object.

3. A pressure release device substantially as hereinbefore described with reference to and as shown in the accompanying drawings.