FR2518886A1 - Automatic sprinkler spray head with pyrotechnic release - uses electrically ignited pyrotechnic device to boil liq. so spray head can be opened under vapour pressure - Google Patents

Abstract

The automatic sprinkler (1) for fire protection in buildings uses destruction of the support (3) holding the sprinkler in the closed position to permit ejection of the closure assembly (3,5,6) and thus permit water flow. A pyrotechnic actuator (15) is coupled (18,19) to the closure assembly support (3). A bifilar electric conductor (22) is used to ignite the pyrotechnic actuator (21), and the heat generated is used to heat a low boiling point liq. in the closure assembly support (3). The vapour pressure generated is sufficient to displace the support, allowing the closure valve to move clear of its seat, releasing water onto the spray head.

Description

Safety water disperser with removable pyrotechnic control, pyrotechnic device for controlling such a disperser, and use of this disperser in a safety sprinkler installation.

The invention essentially relates to a water disperser intended to be connected to a network of pressurized water supply pipes to constitute a safety sprinkler system, the operation of which is switched off in the event of detection. from the start of a fire, this safety water disperser comprising a sprinkler and a pyrotechnic control device which makes it possible to destroy the holding element in the closed position of the shutter of the sprinkler, and d '' eject the shutter assembly.

The invention also relates on the one hand to the pyrotechnic control device which comprises a pyrotechnic cylinder, and on the other hand to the use of these water dispersers in a safety sprinkler installation comprising at least one start detector of fire which is electrically connected to the pyrotechnic device controlling each water disperser.

Safety water dispersers comprising a sprinter and a pyrotechnic control device are known, and, for example, US Pat. No. 3,726, -344 describes a water disperser which uses on the one hand a sprinkler, the holding element of which in the closed position of the shutter is a fusible element, and on the other hand a pyrotechnic heat generator whose heat flow is directed on this fusible element which can be either a plate holding two levers in mutual support, or a spacer placed in the axis of the sprinkler. These ftsible elements are generally produced from a metallic eutectic with low melting point, but these alloys have a low mechanical resistance and it is then necessary to use massive elements having a thickness sufficient to withstand the pressure of the pressurized water which is exerted on the shutter of the sprinkler.

When a fire breaks out in a room whose protection is ensured by a safety sprinkler system comprising a network of water supply pipes fitted with sprinklers, only the sprinklers placed in the zone where the temperature rises abnormally come into action, since it is this rise in temperature which alone can cause the destruction of the holding element in the closed position of the shutter of the sprinkler. Such an installation is therefore ineffective, and this is the reason for which in high-risk and / or reinforced protection areas, the sprinklers are combined with devices for destroying the shutter holding elements, these devices being able to be actuated individually, in groups, or in full, either from manual controls, either from a central smoke, flame or other phenomena detection system.

The devices for destroying the shutter holding elements are essentially: pyrotechnic control devices, such as those described in US Pat. No. 3,726,344 because pyrotechnics allow absolute reliability, a small footprint and only require a low triggering power. On the other hand, the pyrotechnic heat generators must not generate too great a heat flux, since this heat flux could itself be the cause of a fire, and this results in a time of activation of the sprinkler which is too long, especially when the installation protects highly flammable objects or products.

Sprinklers, whose element for holding the shutter in the closed position, consists of a bulb, are also known, and are even more commonly used than sprinklers with fusible elements, but these bulbs cannot be made of thin glass because they must resist the pressure of pressurized water exerted on the shutter of the sprinkler. Glass being a thermally insulating material, it follows that a pyrotechnic heat generator directed on the bulb, which contains a liquid vaporizing at low temperature, generally between 6O0C and 9O0C, results in practically no reduction in the setting time. sprinkler action.

The object of the present invention is to obtain a water disperser whose sprinkler comes into action a few hundredths of a second after the ignition of the pyrotechnic charge of the control device, and this without generating thermal flux and without interfering with the dispersion water, and the invention is characterized in that the pyrotechnic device comprises, on the one hand a pyrotechnic cylinder, the deployment of which ensures the ejection of this holding element, and on the other hand a fixing system which allows the pyrotechnic cylinder to be secured to the shutter assembly of the sprinkler, and preferably the holding element of the sprinkler is a bulb containing a liquid vaporizable at low temperature, this holding element can nevertheless be a spacer made of fusible material.

According to a preferred alternative embodiment, the fixing system is secured to the holding element of the sprinkler, but according to another alternative embodiment the fixing system is secured to the shutter of the sprinkler, this variant of achievements imposing when 1 holding element is a spacer made of fusible material.

The fixing system of the pyrotechnic device advantageously comprises at least one flange which encloses one of the parts constituting the shutter assembly, this assembly being ejected from the sprinkler when it is put into action, and this fixing flange can in particular be a strap, the flexibility of which facilitates adaptation and adjustment of the position of the pyrotechnic device relative to the holding element of the sprinkler.

More particularly, according to the preferred embodiment, the fastening system comprises a first strap which encloses the upper part of the bulb and a second strap which encloses the lower part of the bulb, and> advantageously, the fastening system of the bulb. pyrotechnic device comprises a base secured to the pyrotechnic cylinder, this base being supported on the shutter assembly of the sprinkler. The base is preferably provided with a v-notch which allows centering on the holding element of the sprinkler and this base is made of plastic.

According to the preferred embodiment, the cylinder of the pyrotechnic device comprises a pyrotechnic charge, the igniter of which is connected a two-wire electrical conductor, and this cylinder comprises a metal piston rod whose internal end is initially recessed relative to the sprinkler holding element, the cylinder of this jack advantageously being metallic and the pyrotechnic charge being fixed inside this cylinder.

The pyrotechnic control devices according to the present invention constitute the essential element of the claimed kernel combination, and the use of a water disperser in accordance with the present invention makes it possible to obtain a safety sprinkler installation. whose characteristics correspond to the claimed dispersers.

More particularly, in such a use, the pyrotechnic device for controlling the disperser is connected to a fixed element of the installation by a flexible clip which allows the suspension of this pyrotechnic device, and possibly of the part of the shutter assembly. on which is fixed this pyrotechnic device, outside the water dispersion cone.

Advantageously, the flexible fastener is constituted by the electrical firing conductor of the pyrotechnic cylinder of the control device, and this electrical conductor is fixed on the water supply pipe to the sprinkler or on a fixed element in elevation relative to this sprinkler. .

The advantages obtained thanks to this invention consist essentially in that the time taken to activate the sprinkler is considerably reduced, in particular when the holding element of the sprinkler is constituted by a glass bulb, and when the piston cylinder is initially in withdrawal from this bulb so that rupture occurs by shock. The present invention also makes it possible to improve the operating safety of sprinklers, by eliminating the emission of a thermal flux, which can be the cause of an explosion or a fire, in particular when the sprinkler installation security protects rooms in which products are placed whose vapors are flammable. Obtaining these advantages is all the more interesting as the sprinkler retains all its efficiency, since in operation there remains no part of the pyrotechnic control device in the areas of ejection and dispersion of pressurized water, this device being fixed on the obturation assembly which is ejected from the sprinkler.

In the following, the invention is explained in more detail using a drawing representing the preferred embodiment for which
- Figure l is a front view, in partial section
according to II of a safety water disperser represented
felt in the initial position before triggering, and
connected a pressure water pipe,
- Figure 2 is a bottom view, in broken section
according to Il-I I, from the only safety water disperser,
- Figure 3 is a front view in partial section, which corresponds to Figure l, but shows the
safety water disperser in the operating position
after activation, the parts cons
tituant the shutter assembly having been ejected at
ground during this activation, and the device
control pyrotechnic being shown in section
axial.

FIGS. 1 and 2 represent a safety water disperser whose sprinkler <I) is combined with a pyrotechnic control device (2) which is secured to the holding element (3) of this sprinkler. This holding element is constituted by a glass bulb, which contains a liquid (4) vaporizable at 8O0C, and which forms a frangible spacer interposed between ~ the support bowl (5) and the shutter- (6). The three parts (3), (5) and (6) constitute the shutter assembly, which is ejected from the sprinkler when it is put into action since the support bowl is only placed and centered on the tip. (7) of the body (8) of the sprinkler. This metal body has a top part which is provided with a central bore (9) in which the O-ring obturator adjusts, and an external thread (10 ) which allows connection to the vertical outlet (il) of tubing (12) for supplying pressurized water to the safety sprinkler system. The lower part of the metal body is provided with a notched deflector (13) and the point (7) for positioning the support bowl (5), and the upper and lower parts of this body are connected by lateral arches. (14 and 14 ').

The safety control device (2) consists of the pyrotechnic cylinder (15) and the fixing system (16), the cylinder (17) of stainless steel of the cylinder being directly screwed into the base (18) which is made of plastic and which has a v-notch (Figure 2). This notch allows centering and direct support of the control device on the glass bulb which constitutes the holding element (3) and which has the general shape of an olive, the attachment of this control device on the 'glass bulb being provided by means of the two flanges (19) and (19') which are constituted by cable ties with notched plastic bands.

The base (18) and the flanges constitute a quick fixing system which makes it possible to equip sprinklers which are already mounted on safety sprinkler installations in service. The depth of the notch in the base and the length of the piston rod (20) are such that in the initial position (piston pressed into the cylinder), the end of the piston rod is set back with respect to on the outer surface of the bulb.

A pyrotechnic charge (21) is fixed inside the cylinder, on the bottom, and this charge comprises an electric igniter connected to a two-wire conductor (22), which transmits the ignition pulse generated by a start detector and which is fixed to the tubing tel2) by means of a bracelet (23).

When a fire starts, or an abnormal phenomenon that could degenerate into a fire or explosion, is detected, the closing of an electrical contactor, actuated, either manually or automatically by a central security installation, sends a electric impulse in the two-wire conductor (22), and this electric impulse 'ignites the igniter and the reinforcing pyrotechnic composition which constitute the pyrotechnic charge 121). The gases released by the ignition of this pyrotechnic charge propel the piston (20), and the deployment of the jack (15) causes the percussion of the end of the piston rod on the glass bulb (3).

The bulb is then sprayed under the combined effect of the piston rod which smashes the glass wall and induces a shock in the whole of the bulb, and the thrust of the shutter (6) subjected to the water pressure in the tubing (12). As soon as the bulb is burst, the shutter is completely ejected from the bore (9) of the sprinkler and the support bowl (5î is also ejected, the water gushing on the notched deflector (13) which ensures the dispersion water in a substantially conical volume (24)
The destruction of the holding element (3) completely releases the pyrotechnic control device (2) which, under the combined effect of gravity and the initial ejection of water, is placed outside the zones ejection and dispersion of water, the position of the strap (23) on the tubing (12) and the length of the two-wire conductor (22) being chosen so that the flanges (19, 19 ') of the control device are located outside the water dispersion cone (24).

Claims (15)

Claims 1- Safety water disperser comprising a sprinkler (I) and a pyrotechnic control device (2) making it possible to destroy the holding element (3) in the closed position of the shutter (6) of the sprinkler, and ejecting the shutter assembly (3, 5, 6), characterized in that the pyrotechnic device comprises, on the one hand, a pyrotechnic cylinder (15) whose deployment ensures the ejection of this holding element , and on the other hand a fixing system (18, 19) which allows the pyrotechnic cylinder (15) to be secured to the shutter assembly (3, 5, 6) of the sprinkler. 2- water disperser according to claim 1, characterized in that the holding element (3) of the sprinkler is a bulb containing a liquid (4) vaporizable at low temperature.  3- Water disperser according to one of claims 1 or 2, characterized in that the fixing system (18, 19) is secured to the holding element (3) of the sprinkler. 4- Water disperser according to one of claims 1 or 2, characterized in that the fixing system (18, 19) is integral with the shutter (6) of the sprinkler. 5- Water disperser according to one of claims 1 to 4, characterized in that the fixing system (18, 19) of the pyrotechnic device comprises at least one flange (19) which encloses one of the parts constituting the shutter assembly which is ejected from the sprinkler. 6- water disperser according to one of claims 2, 3 or 5 characterized in that the fixing system (18, 19) comprises a first strap which encloses the upper part of the bulb and a second strap which encloses the lower part of the bulb. 7- Water disperser according to one of claims 1 to 3, characterized in that the fixing system (18, 19) of the pyrotechnic device comprises a base (18) integral with the pyrotechnic cylinder (15), this base being in support on the shutter assembly (3, 5, 6) of the sprinkler. 8- Water disperser according to one of claims 3 or 7, characterized in that the base (18) is provided with a v-notch which allows centering on the holding element (3) of the sprinkler. 9- Water disperser according to one of claims 7 or 8, characterized in era that the base (18) is made of plastic. 10- Water disperser according to claim 1, characterized in that the jack (15) of the pyrotechnic device comprises a pyrotechnic charge (21) whose igniter is connected to an electrical conductor (22) two-wire. 11- Water disperser according to one of claims 1 or 10, characterized in that the pyrotechnic cylinder (15) comprises a piston rod (20) metal whose external end is initially recessed relative to the holding element (3) of the sprinkler. 12- Water disperser according to one of claims 1, 10 or 11, characterized in that the pyrotechnic cylinder (15) comprises a metal cylinder (17) inside which is fixed the pyrotechnic charge (21). 13- Pyrotechnic control device, characterized in that it conforms to one of claims 1 or 3 to 12.  1 Use of a water disperser in a safety sprinkler system, characterized in that the disperser conforms to "one of claims 1 to 12. 15- Use of a water disperser according to claim 14, characterized in that the pyro technical control device (2) of the disperser is connected to a fixed element of the installation by a flexible clip which allows the suspension of this pyrotechnic device outside the water dispersing cane (24). 16- Use of a water disperser according to claim 15, - characterized in that the flexible attachment is constituted by the electrical conductor (22) for igniting the pyrotechnic cylinder (15) of the control device (2) . 17- Use of a water disperser according to claim 16, characterized in that the electrical conductor (22) is fixed on the tube (12) for supplying water to the sprinkler (1).