RU2444389C1 - Method to extinguish forest fires and helibucket - Google Patents

Abstract

FIELD: fire-prevention facilities.

SUBSTANCE: invention relates to methods for extinguishing of large forest fires, and also in extinguishing of fires in difficult-to-access areas with the help of helicopters. The substance of the proposed technical solution consists in the fact that in the method for extinguishing of forest fires that consists in delivery of a fire-extinguishing composition to an area on fire with the help of an aircraft and its supply by pouring from a helibucket into the fire focus, in process of pouring the flow of the fire-extinguishing substance is swirled. In the helibucket comprising a reservoir for delivery of the fire-extinguishing composition, an external suspension and a facility to organise pouring of the fire-extinguishing composition to the fire focus, at the outlet of the reservoir there is a blade device installed to swirl the flow of the fire-extinguishing composition.

EFFECT: inventions provide for increased efficiency of helibucket operation due to swirling of the fire-extinguishing composition flow and elimination of burning products discharge from the fire focus or reduction of its negative effect in case of extinguishing by means of pouring.

2 cl, 29 dwg

Description

The invention relates to methods for extinguishing large forest fires, as well as extinguishing fires in inaccessible places using helicopters.

It is known that heavy equipment often arrives at the scene of fires when the speed of flame propagation begins to overtake the speed of movement of tractors and bulldozers in the forest, and often the fire devours equipment. Those fire engines with gas tanks, which with great difficulty get to the places of fire, cannot come very close to the edge of the fire (Yu.L. Vorobyov, V.A. Akimov, Yu.I. Sokolov; edited by Yu.L. Vorobyov, Forest fires in Russia: Status and problems, EMERCOM of Russia. - M.: DEKS-PRESS, 2004, p. 187).

The problem of water delivery in these conditions is solved using helicopters, on the external slider of which a special container is fixed - a spillway device, taken as a prototype of the proposed method and device (Yu.L. Vorobyov, V.A. Akimov, Yu.I. Sokolov; under the general Edited by Yu.L. Vorobyov, Forest Fires in Russia: Status and Problems, EMERCOM of Russia. - M.: DEKS-PRESS, 2004, p.188-189).

A spillway device includes a container with a fire extinguishing composition.

The capacity is able to accommodate from five to fifteen cubic meters of water. It is designed so that it can be filled in a matter of seconds: the helicopter hangs over any body of water, the winch lowers the spillway. And after half a minute you can already fly to the place of fire.

However, working with a spillway device is very difficult and dangerous, it requires high training of the flight crew. Water sampling and discharge requires jewelry accuracy and coordination of the helicopter crew's actions (Yu.L. Vorobyov, V.A. Akimov, Yu.I. Sokolov; edited by Yu.L. Vorobyov. Forest fires in Russia: Condition and problems. EMERCOM of Russia. - M .: DEKS-PRESS, 2004, p. 189).

In addition, the disadvantage of this device is that when a large mass of water is discharged to the fire source, it has a significant dynamic effect on approaching the burning surface when it approaches the combustion surface, resulting in an intense release of combustion products from the zone of interaction of the front part of the spout with the surface of the fire source in the initial stage of extinguishing a fire. Moreover, the spread of burning firebrands and other forest vegetation can reach several hundred meters. All this leads to the fact that in some places it is possible to achieve complete extinguishing using a spillway device, and in other places with a strong wind the fire can only intensify or re-ignite again. This phenomenon is especially dangerous when extinguishing the edge of the fire in hard to reach places.

The purpose of the proposed technical solution is to reduce the effects of dynamic interaction of a liquid fire extinguishing agent when spilling from a spillway device with a burning surface, by reducing or eliminating the release of combustion products from the interaction zone in the initial stage of extinguishing a fire.

The essence of the claimed technical solution lies in the fact that in the method of extinguishing forest fires, which consists in delivering a fire extinguishing composition to a fire place with the help of an aircraft and supplying it in an outflow from a spillway device to a fire source, when a spout is released, the flow of the extinguishing agent is twisted, and in a spillway device, implementing the inventive method, comprising a container for delivering a fire extinguishing composition, an external suspension and means for organizing a spout of a fire extinguishing composition to a fire, shovels are installed at the outlet of the tank -screw unit performing spin flow of extinguishing agent.

The extinguishing effect using the inventive device is achieved by the fact that when the front part of the spout of the extinguishing agent arrives, its swirling flow blocks the intense emission of combustion products from the zone of dynamic interaction of the front part of the spout with the surface of the fire center in the initial stage of extinguishing the fire. Moreover, this phenomenon can be explained by the fact that particles of combustion products that tend to fly out of the dynamic interaction zone noted above are carried away by a circular flow of fire extinguishing composition, and their initial momentum of movement in a direction perpendicular to the tangential velocity of a circular motion of particles of a fire extinguishing agent, completely dies or significantly decreases.

Installation at the outlet of the capacity of the blade apparatus allows you to swirl the flow of the extinguishing agent.

The application of the proposed method and device allows to increase the efficiency of the spillway device by swirling the flow of the extinguishing agent and to exclude the emission of combustion products from the fire source during fire extinguishing or to reduce its negative impact.

Figure 1 presents schematically an aircraft with a spillway at the time of approaching the center of a forest fire; figure 2 is the same at the time of extinguishing the focus of a forest fire from a spillway when pouring a swirling flow of extinguishing agent into the extinguishing zone (the inventive method); figure 3 - the same at the time of extinguishing the focus of a forest fire from the spillway during spout without swirling the flow of the extinguishing agent into the extinguishing zone (prototype method); Figure 4-11 presents the video footage of the process of formation from a stationary spillway device using the inventive method of the spout core of a swirling stream of fire extinguishing composition and the process of interaction of its front part with the surface of the bulk pyrotechnic mixture (cold experiments); 12-17 show frames of a video recording of the process of formation of a fire extinguishing agent stream stream (without spin) from a stationary spillway device (using the prototype method) and the process of interaction of its front part with the surface of the bulk pyrotechnic mixture (cold experiments); Figs. 18-23 show frames of a video recording of the process of extinguishing a burning bulk pyrotechnic mixture using the inventive method and the process of interaction of its front part with the surface of the bulk pyrotechnic mixture (hot experiments); on Fig-29 presents the video footage of the process of extinguishing the burning bulk pyrotechnic mixture using the prototype method and the interaction of its front part with the surface of the bulk pyrotechnic mixture (hot experiments).

A spillway device that implements the inventive method (FIG. 1) consists of an aircraft 1, to the fuselage of which is mounted an external spillway 2, a spillway device 3 filled with a fire extinguisher 4.

The means of organizing the spout of the extinguishing agent to the fire is made in the form of a confuser socket 5 and a hinged cover 6.

At the outlet of the tank 1, a blade apparatus 7 is installed, which is a blade evenly spaced around the perimeter, which swirls the flow of the extinguishing agent when spilling onto a fire.

The device operates as follows. After a forest fire is detected, for example, by an observer pilot of civil aviation and as a result of reconnaissance of the area, the observation data is sent to the dispatch control center, which sends the aircraft 1 to extinguish the fire, for example, the Mi-26 T.

When approaching a predetermined source of fire, the aircraft 1 hangs over it (Figure 1). Then the cover 6 means organizing the spout of the extinguishing agent at the command of the pilot opens. After which the spout of the extinguishing agent 4 from the tank 3 is made on a given area of extinguishing of the fire center 8 (Figure 2). Moreover, when spouting, the flow of the extinguishing agent 4 is twisted using a spatula 7 in accordance with the claimed method.

When approaching the front part of the spout of the extinguishing agent 4, its swirling flow blocks the intense release of combustion products from the zone of dynamic interaction of the front part of the spout with the surface of the fire center 8 in the initial stage of extinguishing the fire.

In the case of the spill of the extinguishing agent 4 without twisting its flow, an intense emission of combustion products 9 from the previously mentioned interaction zone in the initial stage of extinguishing the fire is observed (Figure 3). Moreover, the spread of burning firebrands and other forest vegetation can reach several hundred meters (depending on the discharge height of the extinguishing agent 4).

To confirm the effectiveness of the proposed method, experiments were performed on a stationary spillway device.

A spillway device was installed at a height of 1.0 m above a bowl with a diameter of 0.3 m, in which a bulk pyrotechnic mixture weighing about 1 kg was placed. 75 liters of water were poured into the container. The diameter of the outlet of the tank was 0.5 m.

On command, the bottom of the tank was opened and the extinguishing agent was poured onto the bulk surface of the pyrotechnic mixture.

In the first series of tests (cold experiments), both a spout of a swirling flow of a fire extinguishing composition (Figs. 4-11) and a spout of a flow of a fire extinguishing composition without swirl (Figs. 12-17) were performed.

In the second series of tests (hot experiments), both a spout of a swirling flow of a fire extinguishing composition (Fig. 18-23) and a spout of a flow of a fire extinguishing composition without swirl (Figs. 24-29) were performed.

In this series of tests, the bulk surface of a pyrotechnic mixture was quenched after 0.2 s of free combustion of this mixture.

At a distance of about 1.0 m from the bowl, a mannequin was installed in work clothes.

The results of the first series of tests (cold experiments) showed that in the case of application of swirling the flow of extinguishing agent during spout, the following phenomena are observed:

- when approaching the front of the spout of the extinguishing agent, its flow swirls (Figure 5-9);

- in the zone of dynamic interaction of the frontal part of the spout with the surface of the bulk pyrotechnic product, the intensive emission of part of the bulk pyrotechnic mixture is blocked (Figure 10-11).

In the case of the use of a flow of extinguishing agent without its twisting during spout, the following phenomena are observed:

- when approaching the front of the spout of the extinguishing agent, its flow remains unperturbed (Fig.12-14);

- in the zone of dynamic interaction of the frontal part of the spout with the surface of the bulk pyrotechnic product, an intense discharge of part of the bulk pyrotechnic mixture is observed (Fig.15-17).

The results of the second series of tests (hot experiments) showed the following results.

In the case of application of swirling the flow of extinguishing agent during spout, the following phenomena are observed:

- the bulk surface of the pyrotechnic mixture is ignited (Fig. 18);

- formed a swirling flow of fire extinguishing composition (Fig.19-20);

- when approaching to the burning bulk surface of the pyrotechnic mixture of the front part of the spout of the extinguishing agent, the dynamic interaction of the front part of the spout with the named burning surface occurs (Fig.21);

- in the zone of dynamic interaction of the frontal part of the spout with the burning surface of the bulk pyrotechnic mixture, the intensive emission of part of the said mixture is blocked (Fig. 22);

- after extinguishing from a spillway device, clothing is not tanned on a mannequin (Fig. 23).

In the case of the use of a flow of extinguishing agent without its twisting during spout, the following phenomena are observed:

- ignition of the bulk surface of the pyrotechnic mixture is performed (Fig.24);

- the flow of the extinguishing composition without spin is formed by pouring the extinguishing composition onto the burning surface of the bulk pyrotechnic mixture (Fig.25-26);

- when approaching to the burning bulk surface of the pyrotechnic mixture of the front part of the spout of the extinguishing agent, there is a dynamic interaction of the front part of the spout with the named burning surface (Fig. 27);

- in the zone of dynamic interaction of the frontal part of the spout with the burning surface of the bulk pyrotechnic mixture, an intensive discharge of part of the said mixture occurs (Fig. 28);

- after extinguishing from a spillway device, clothing on a mannequin is tanned (Fig. 29).

The test results of a stationary spillway device showed that the application of the proposed method and device allows to increase the efficiency of the spillway device by swirling the flow of the extinguishing agent and to exclude the emission of combustion products from the fire source during extinguishing or to reduce its negative impact.

The proposed spillway device is easy to operate and allows you to upgrade existing spillway devices with minimal material costs.

The claimed technical solution is able to increase the efficiency of extinguishing large forest fires, as well as extinguishing fires in hard-to-reach places using helicopters and has a great potential in the practice of ensuring fire safety of other objects.

Claims (2)

1. A method of extinguishing forest fires, which consists in delivering a fire extinguishing composition to a fire site using an aircraft and supplying it in an outflow from a spillway device to a fire, characterized in that during the outflow a stream of extinguishing agent is spun. 2. A spillway device that implements the method according to claim 1, comprising a container for delivering a fire extinguishing composition, an external suspension, and means for organizing a spout of a fire extinguishing composition to a fire source, characterized in that a blade apparatus is installed at the outlet of the tank for swirling the flow of the fire extinguishing composition.

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