EP0760719B1 - Method and device for extinguishing fires - Google Patents

Abstract

PCT No. PCT/EP95/02964 Sec. 371 Date Sep. 27, 1996 Sec. 102(e) Date Sep. 27, 1996 PCT Filed Jul. 26, 1995 PCT Pub. No. WO96/04960 PCT Pub. Date Feb. 22, 1996What is disclosed is a device for extinguishing fires, and utilization of the device for stationary protection of specific objects, and for dust abatement during blasting operations, and a method for extinguishing forest or terrain fires with the extinguishing device. The extinguishing device comprises a container for receiving an extinguishing agent, and an explosive in or on this container, by means of detonation of which the extinguishing agent is atomized to form a mist and brought into the fire. In order to increase the flexibility and effectiveness in practical use, the container consists of a flexible hose which may be closed at both ends. The method of extinguishing forest or terrain fires with this device provides for the hose to be laid out in front of the fire front, filled with the extinguishing agent, and exploded by detonation of the explosive.

Description

The present invention relates to a device for extinguishing fires, with a container for holding an extinguishing agent, and with an explosive in or on this container, by the ignition of which the extinguishing agent is atomized into a mist and set on fire. The invention further relates to a method for extinguishing forest or wildfires using the described device.

It is known to atomize an extinguishing agent into the finest particles using an explosive with the aim of extinguishing fires. When a preferably explosive explosive charge is detonated inside or in the vicinity of a homogeneous medium such as water, a pressure of several thousand bar arises, as a result of which the water is atomized into extremely fine particles and thrown radially from the center of the explosive charge into the environment with the pressure wave that arises. A high-explosive charge is understood to mean one that generates a detonation wave with a propagation speed of over 5000 m / sec. Due to the small size of the individual droplet droplets, the extinguishing agent mist has a very large total surface in relation to the amount of extinguishing agent used, with which the extinguishing agent mist lies on the fire in the vicinity of the blasted container and extinguishes it by the known supercooling effect. In addition, the extinguishing effect when blasting an extinguishing agent is based in a known manner on the blow-out effect of the detonation wave.

From US 1,119,799 and from EP 390 384, fire extinguishers intended for stationary use are known which take advantage of the above-described effect of detonating an extinguishing agent. These known fire extinguishing devices have a cylindrical container for containing an extinguishing agent and a concentrically arranged elongated inner container which extends longitudinally in the extinguishing agent container and is filled with an explosive charge.

Such a fire extinguisher is known from EP 488 536, in which the explosive charge, in contrast to the two fire extinguishers described above, is attached to the outside of the extinguishing agent container.

US 3,980,139 and FR 1,473,621 each disclose a "fire-fighting bomb" consisting of a cylindrical glass or plastic container for holding an extinguishing agent, and a cylindrical, concentrically arranged inner container which in turn contains the explosive. The difference between these fire-fighting bombs and the fire-extinguishers described above is only the ignition of the explosive, which takes place in the bombs either by a radio signal or by the action of heat when the fire-fighting bomb is thrown into a fire.

All the known fire extinguishing devices described above have the disadvantage in common that they are only insufficiently flexible and effective in their practical use when extinguishing fires. The stationary fire extinguishers always only have a selective effect, so that large-scale fire protection or large-scale fire fighting is prohibited for economic reasons, since too many such fire extinguishers would have to be used. With regard to mobile fire fighting, for example in forest or other wildfires, the described "fire-fighting bombs" have proven to be disadvantageous, since by dropping the fire-fighting bomb they do not have a targeted, directed extinguishing effect due to the blasting and, moreover, are more likely to ignite the fire if they are ignited in the middle of the fire. After all, it is cumbersome and costly, and not least unsatisfactory in terms of hit accuracy, to drop the extinguishing devices over the source of the fire.

The present invention has for its object to provide a more adaptable and effective device for extinguishing fires.

This object is achieved by the device for extinguishing fires with the features of claim 1 and with the method for extinguishing forest or wildfires with the features of claim 11.

Both the device according to the invention and the method have a whole series of advantages which considerably increase the effectiveness in fire fighting. For the following description of the advantages, "mobile" fire fighting means the extinguishing of fires by task forces. Such fires are, for example, forest or wildfires or even fires in industrial plants or normal buildings. "Stationary" fire fighting is to be understood to mean the extinguishing of fires by means of an extinguishing device according to the invention that is permanently installed and ready for use at the hazard location. The systems or buildings to be protected thereby have a wide spectrum; This includes, for example, oil or gas tanks, refineries, oil drilling or production facilities, runways or refueling areas at airports and the like.

The extinguishing device according to the invention is distinguished in mobile use in that it can be adapted to the course of the flame front and thus to the threat over almost unlimited lengths. The hose, which is initially not filled with extinguishing agent, is unrolled and laid out, for example from drums, like a conventional fire hose. An almost unlimited spatial range of use is thereby achieved. The arrangement of several hose lines spaced parallel to one another enables several fire-fighting lines and thus an almost unlimited depth of use to be generated. The flexible hose can be manufactured by the meter and is easily transportable when rolled up.

These advantages make it clear that the extinguishing device according to the invention is outstandingly suitable for combating a large fire. By appropriately laying out the flexible hose, it can be achieved that the fire is "enclosed", as the technical term for surrounding a source of fire is, while at the same time fighting from all sides.

With regard to stationary fire fighting, ie especially for industrial applications, the extinguishing device according to the invention is also characterized by its great flexibility in design. Since even the smallest cantilever radii are possible, the extinguishing device can, for example, be guided around furnishings such as rules or the like or around structural obstacles such as columns or the like when installed in a warehouse. It is also conceivable to hang the flexible hose over high racks. Thus, a maximum adaptation of the stationary extinguishing device to potential sources of danger is also possible here.

For both mobile and stationary fire fighting, the advantage of the device according to the invention is that the extinguishing agent mist can be generated quickly, flexibly and inexpensively at the scene. The basic materials required for this, namely water and possibly an extinguishing agent additive ("RETARDER") and the disintegrant, can be stored in a confined space for a long time without any problems and can also be easily transported. It also follows that the device according to the invention for stationary fire protection can be permanently installed or - for mobile fire fighting - can be used variably on site, even where conventional extinguishing methods fail, for example because of water shortages. Furthermore, fires of different fire classes can be extinguished safely by the device according to the invention. Since a relatively small amount of extinguishing agent is used due to the increase in surface area due to the atomization of the extinguishing agent, fire fighting causes far less damage than when conventional extinguishing methods are used. Both proper blasting itself and the atomized extinguishing agent do not endanger the fire environment. When using the extinguishing device in such industries that produce or process powder-like products, it is also of great advantage that the powder is bound by the extinguishing agent mist after a dust explosion or the like.

Advantageous developments of the invention are specified in the subclaims.

Two alternatives are provided for the formation of the explosive that extends linearly in or on the container: firstly, the explosive can be designed as a flexible detonating cord that extends in the longitudinal direction of the hose, and secondly, discrete linear explosive charges can also be provided, which are also shown in FIG Longitudinal direction in uniform Distances are arranged in or on the hose. An advantage of both types of explosives is that the hose with the explosive can be manufactured as a finished unit by the meter. This reduces both the manufacturing costs and the time required for on-site use.

The flexible hose preferably consists of a thin-walled but relatively resistant material. The choice of hose material will be made so that it is as tough as necessary and as flexible as possible. The resistance in mobile use is only intended to ensure that no holes are caused by branches or sharp stones when the hose is laid out and then filled with extinguishing agent. The flexibility will be based on the criteria that the hose should be able to be rolled up and that the smallest extension radii are possible. In addition, the hose should have the lowest possible weight. Thin-walled plastic hoses are preferably used, which could be described as "burstable" within the scope of the above requirements. The selection of the hose material described also avoids endangering people by throwing away hard materials, such as are used, for example, in the known fire-fighting bombs or the like. Even hard PVC could endanger people from a distance.

In addition, the hose has protection against heat radiation, for example by being made of white material or having an aluminum coating.

While the hose will usually have a circular cross-section, it is also conceivable for special applications that the hose has a triangular cross-section when filled. This cross-section enables a stable position of the hose and thus the possibility to color-code a certain side of the triangle, for example, which should face the source of the fire. This is particularly advantageous if the detonating cord is at the angle of the triangular hose, which is opposite the triangle side facing the source of the fire. A directed explosive effect can thereby be achieved in a particularly effective manner. This can be supported by the fact that the side of the triangular hose facing the source of the fire is weaker than the other two sides.

A goal when blowing up the hose filled with extinguishing agent is to remove as much pressure as possible from the surface on which the hose rests in order to bring as much extinguishing agent into the air. For this purpose, it is preferably provided that the disintegrant, for example one or more detonating cords, is arranged at a distance of approximately one third of the hose diameter from the floor or from a holder where the hose rests. Such a positioning can be realized most simply by gluing two hoses in parallel and picking up the detonating cord between the two hoses in contact. By lifting the detonating cord from the surface, an excellent distribution and alignment of the extinguishing agent mist can be achieved.

To use the extinguishing device for stationary object protection, it is provided that the hose with the disintegrant is arranged on an elongate carrier, for example a bowl-shaped or angular cross-section. On the one hand, this results in a stable storage of the hose, and on the other hand a directed effect when the extinguishing agent is blown up, since the hose is shielded from the rear by the carrier while the forward effect towards the source of the danger is not impaired.

The advantage of stable, stationary storage of the ready-to-use extinguishing hose can be seen from the fact that the hose on the carrier can preferably be constantly filled with the extinguishing agent.

In addition to an object fire protection device for stationary systems or facilities, the extinguishing device according to the invention is also suitable for binding dust during blasting work, for example when buildings are blown up, in that the hose is at least partially laid out around the object to be blasted, filled with water and when the dust front arises by ignition of the explosive is blown up. If necessary, several protective walls can be laid out around the object to be blown up, which are then fired sequentially. This makes it possible to effectively combat the great dust nuisance that has previously occurred when buildings are blown up.

In addition, the extinguishing device according to the invention can be used as a preventive fire protection device on or on an airport runway or an aircraft parking position. As a preventive measure in the event of a hip emergency landing of an aircraft, it is known from the prior art to apply an approximately 1000 m long and 60 m wide foam carpet to the runway. However, this takes 45 to 60 minutes, and the cost of the equipment required for this is very high. Runway foaming has not been carried out for some time because, in addition to the enormous expenditure of time and money, the meaning of such foaming has been questioned. Because of the foam carpet, the aircraft can become uncontrollable during the emergency landing and move out of the side of the runway, so that the rescue work are more likely to be hindered. The critical moment and thus also the critical position in the emergency landing of an aircraft is only reached when the aircraft comes to a standstill and fuel that leaks is ignited. This is exactly where the extinguishing device according to the invention comes into play by laying the hose along the runway, filling it with the extinguishing agent and detonating it at the critical moment by igniting the explosive. The finest extinguishing agent particles generated by the blasting rain down on the activated critical area and form a surface film that leads to a closed surface within a very short time and thus prevents the fuel from igniting.

Another possible application of the extinguishing device according to the invention is in preventive fire protection in an aircraft parking position, where the aircraft are generally also refueled. There it would be conceivable to install a hose front between the aircraft and the terminal building, which can be constantly filled with extinguishing agent and, in an emergency, can lay a finest film of extinguishing agent over the protected area.

In the following, the invention is explained in more detail in some exemplary embodiments with reference to a drawing.

Figur 1

einen schematischen Querschnitt eines Spreng-Löschschlauches mit innenliegendem Sprengmittel;

Figur 2

einen schematischen Querschnitt eines Spreng-Löschschlauches mit außenliegendem Sprengmittel;

Figur 3

einen schematischen Querschnitt eines Schlauchbündels aus drei Spreng-Löschschläuchen;

Figur 4

einen schematischen Querschnitt eines dreieckförmigen Spreng-Löschschlauches;

Figur 5

eine schematische Ansicht eines Waldbrandes mit linienförmigem Verlauf der Flammenfront;

Figur 6

eine schematische Ansicht eines Waldbrandes mit unregelmäßigem Verlauf der Flammenfront;

Figur 7

eine schematische Darstellung eines Öltanks mit stationär angeordneter Löschvorrichtung im Querschnitt; und

Fig. 8

eine schematische Darstellung einer Landebahn eines Flughafens mit stationär angeordneter Löschvorrichtung in der Draufsicht.

Show it:

Figure 1

a schematic cross section of an explosive fire hose with internal explosive;

Figure 2

a schematic cross section of an explosive fire hose with external explosive;

Figure 3

a schematic cross section of a hose bundle from three explosive fire hoses;

Figure 4

a schematic cross section of a triangular explosive fire hose;

Figure 5

a schematic view of a forest fire with a linear course of the flame front;

Figure 6

a schematic view of a forest fire with an irregular course of the flame front;

Figure 7

a schematic representation of an oil tank with a stationary extinguishing device in cross section; and

Fig. 8

a schematic representation of an airport runway with stationary extinguishing device in plan view.

In the figures of the drawing, arrows 7 each show the main direction of propagation of the blown-up extinguishing agent and the pressure wave.

FIG. 1 shows a flexible hose 2 of any length, which is circular in cross section and made of a thin-walled plastic material, which is filled with an extinguishing agent 10. Where the hose 2 rests on the floor (not shown), a linear flexible detonating cord 4 made of highly explosive explosive runs within the hose at a distance of about a third of the hose diameter from the bottom of the hose, which is water-resistant, hardly flammable and can be stored almost indefinitely is. With these properties, the explosive can be used both in a mobile and in a stationary application of the extinguishing device.

If the detonating cord 4 is ignited, the extinguishing agent is atomized into the finest droplet of extinguishing agent by the excess pressure in a fraction of a second and distributed almost uniformly radially in all directions in the direction of the arrows 7. This creates an approximately semicircular cross-section of the extinguishing agent mist on the environment.

If instead, as shown in FIG. 2, the detonating cord 4 is arranged outside the filled hose 2, an essentially directed detonating and extinguishing effect can be achieved. The detonating cord 4 is positioned on the side of the hose 2 facing away from the source of the fire on the floor (not shown). This also helps to fight the fire very effectively, in which far more than 50% of the extinguishing agent can have a direct extinguishing effect.

In some cases it can be useful to form a tube bundle from several tubes 2, as is shown schematically in cross section in FIG. 3. Here the detonating cord 4 is arranged in the center of the tube bundle. Of course, other positions up to the use of several detonating cords at different locations are also conceivable.

FIG. 4 shows a shape deviating from the circular cross-sectional shape of the tube 2. The tube 2 shown there has a triangular cross-sectional shape, and the detonating cord 4 is arranged at the angle of the triangular tube 2, that of the triangular side or tube wall 1 which faces the source of the fire is opposite. With this arrangement, an essentially directed explosive and extinguishing effect in the direction of arrows 7 can also be achieved. This directional effect could be supported, for example, in that the side 1 of the hose 2 facing the source of the fire is made materially weaker than the two other triangle sides 3, 5. In addition, side 1 can be marked in color in order to ensure proper positioning of the detonating cord in the hose in relation to the source of the fire or the direction of the threat when the extinguishing device is laid out.

Figure 5 shows a schematically illustrated forest fire. The fire front 8 moves from right to left in the illustration. To extinguish the fire, for example, a hose 2 according to FIG. 1 was laid along the entire fire front 8 with the detonating cord 4 contained therein and filled with extinguishing agent. If the detonating cord 4 is detonated, the extinguishing agent atomized into a mist spreads to both sides of the hose 2 over a width of 50 m each. The flames 9 are extinguished in the manner described above both by the supercooling effect and by the detonation wave associated with the explosion. On the opposite side of the hose 2, the area of the forest that was not covered by the fire front 8 is moistened by the extinguishing agent mist.

FIG. 6 shows a schematically illustrated, irregularly extending fire front 8. Using this schematic illustration, one advantage of the extinguishing device according to the invention can be shown particularly clearly: if the fire were combated with known, non-flexible extinguishing devices, for example by stringing together rigid extinguishing agent containers along the line 14 shown in broken lines, the extinguishing agent contained in the containers would only have an effect in the most advanced area 17 of the fire front 8 when it was detonated, while in areas 15, 16 no extinguishing effect would be achieved. In contrast, the flexible extinguishing agent hose 2 enables the control line to be adapted to the shape of the flame front 8 and thus a very effective use of the extinguishing agent. About that In addition, the extinguishing device can be used in the shortest possible time, since the hose 2 in front of the fire front 8 can be designed like a normal C hose, filled with the extinguishing agent 10 and blasted by igniting the explosive. Here, by increasing the surface area of the extinguishing agent due to the atomization to a fine mist, an optimal efficiency of the amount of extinguishing agent used can be achieved. Furthermore, the use of the method according to the invention is also ecologically harmless. The use of extinguishing agent leaves hardly any traces and the loss of biological substance can be reduced to a minimum due to the high efficiency of the process.

FIG. 7 shows an example of a stationary application of the extinguishing device in object protection. Shown is a schematic cross section of an oil tank 12, which has a circumferential bracket-like support 6 with an angular cross section at the level of its upper edge 13. The hose 2 filled with extinguishing agent rests on the carrier 6. The position of the detonating cord 4, which is not shown here, is of secondary importance here. The alignment of the explosive and extinguishing effect in the direction of the arrows 7 is achieved in this embodiment by the shielding of the hose on the back by the carrier 6. The extinguishing device is automatically detonated by sensors when the fuel contained in the tank 12 ignites. Immediately after the detonation, the extinguishing agent mist covers the burning fuel like a lid and extinguishes the fire in the manner described above. The stationary use of the extinguishing device described in this way can of course also be transferred to the protection of high racks in storage rooms or the like.

FIG. 8 shows a schematic plan view of an airport runway 18 with an aircraft 19 located thereon.

The area on a runway 18 in which an emergency landing aircraft 19 comes to a standstill is referred to as a critical area 20, which is indicated here by a dash-dotted line. This critical area is approximately 600 to 1,000 meters long and its location can generally be predicted for any type of aircraft. Left and right of the runway 18, for example, 5 lengths of tubes 21 are arranged in a total of 10 segments 22 to 31. Depending on where the aircraft 19 comes to a stop during an emergency landing, the corresponding segments 22 to 31 are activated. Since several such hoses 21 can also be arranged parallel to one another, a second row of hoses (not shown here) could also be used as a so-called "second alarm wave", which is activated when the extinguishing agent supply of the fire-fighting vehicles has been used up.

Claims (11)

1. Device for extinguishing fires, with a container for receiving an extinguishing agent (10), and with an explosive in or on said container, by means of the detonation of which the extinguishing agent (10) is atomised to form a mist and is applied to the fire,
   characterised in that
   the container is a flexible hose (2) closable at both ends.
2. Device according to claim 1,
   characterised in that
   the explosive is in the form of a flexible explosive cord (4) which extends in the longitudinal direction of the hose (2).
3. Device according to claim 1,
   characterised in that
   the explosive is in the form of discrete linear explosive charges, and is distributed at regular intervals.
4. Device according to one of claims 1 to 3,
   characterised in that
   the hose (2) comprises a thin-walled but resistant material.
5. Device according to one of claims 1 to 4,
   characterised in that
   the hose (2) comprises a material reflective of radiant heat, or has a protective coating for this purpose.
6. Device according to one of claims 1 to 5,
   characterised in that
   the explosive is located at a distance of approximately one-third of the hose diameter away from the ground or from a retaining means upon which the hose (2) rests.
7. Device according to one of claims 1 to 6,
   characterised in that
   the hose (2) is disposed with the explosive on a longitudinally-extended carrier (6) which is for example shell-shaped or angled in cross-section.
8. Use of the device according to one or more of claims 1 to 7 as a fire-protection device for specific objects, for stationary installations or devices.
9. Use of the device according to one or more of claims 1 to 7 for dust-abatement during blasting operations,
   characterised in that
   the hose is laid at least partly around the object to be blasted, is filled with water and is detonated by ignition of the explosive when the dust front arises.
10. Use of the device according to one or more of claims 1 to 7 as a preventative fire-protection device at or on an aircraft runway, or an aircraft parking area,
    characterised in that
    the hose (2) is laid out at least partly along the runway or around the parking area to be protected, is filled with the extinguishing agent (10), and is detonated by ignition of the explosive when a fire risk occurs.
11. Method of extinguishing forest or terrain fires with a device according to one or more of claims 1 to 7,
    characterised in that
    the hose (2) is laid out in front of the flame front (8), is filled with the extinguishing agent (10) and is detonated by ignition of the explosive.

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