RU2742430C1 - Fire extinguishing method - Google Patents

Abstract

FIELD: methods of effective fire extinguishing.

SUBSTANCE: invention relates to methods of effective fire extinguishing implementing pulse and targeted principle of action on source. Fire extinguishing method using a device comprising a fire extinguishing agent and delivered by a known method to a fire source identified by location and nature of the fire and providing pulse release of said substance to the burning object due to gas pressure in ignition of fuse charge installed in rear part of device, and in contact with fire extinguishing agent and blow-off charge. According to the invention, the device used is a fire extinguishing projectile (FEP), having a cylindrical sleeve with an agent fixed in the form of a stopper and made in the form of a cylinder with a cover and a bottom, setting the fire extinguishing agent type, calculating its required amount and caliber of projectile for its placement, setting on fuse timer required value of flight time for ignition of blow-off charge, adjusting the free running length of the sleeve by the retainers, providing the pulse output of the agent specified in the value at the required moment in time, placing it on the delivery vehicle and firing in the direction of the target, when approaching to which in preset time interval electric current is supplied to ignition plug, note here that explosive charge of ignition charge is ignited, which leads to case movement with discharge of tip and cover with subsequent impact of cartridge bottom on ledges of stoppers, which provides pulse release of the whole agent to target proportionate to free stroke of cartridge. High efficiency of fire extinguishing is achieved by directed emission of FEP at the specified height, at the same time it is required in several times fewer shells than in case of explosive non-directional throwing of FEP into the fire zone to obtain the same result.

EFFECT: high efficiency of fire extinguishing.

1 cl, 1 tbl

Description

The invention relates to a technique for pulsed fire extinguishing and spraying substances in a gaseous environment, preferably in air, and can be used to spray a significant amount of fire extinguishing agent (OS) in a short period of time, in particular for fire extinguishing purposes.

Numerous tests and results of real fires have shown that an OS sprayed with an undirected detonation over a fire source (equally applied with an undirected detonation in a fire source on the ground) “blows away” by ascending heated flows before it has time to form into a sprayed “cloud” in the chemical zone. thermal decomposition reactions, because the velocity of gas flows in the combustion area, and even more so in the epicenter, reaches several tens of meters per second (and can reach a value of about 100 m / s). To overcome this barrier, the kinetic energy (velocity head) of the OC flow (at the final stage) must exceed the same indicator of the ascending heat flows. That is practically impossible with non-directional OS feed.

Therefore, the most effective methods in the field of fire extinguishing are those that ensure the prompt, targeted delivery of the fire extinguishing agent (OS) and its impulse, almost instantaneous, release to the fire site.

Known methods of fire extinguishing by pulsed exposure to a stream of OS with high kinetic energy, in particular, due to the energy of a rapidly expanding working gas. One such method (IFEX US Pat. No. 5,305,957) is to eject the OC at a high speed using compressed air energy. The disadvantage of this method is the low range, low utilization of the extinguishing agent and the need to use expensive and bulky high pressure equipment (up to 3000 atm.).

Known installation with a container of sprayed OS, laid in the barrel, which allows you to spray fire extinguishing substances by impulse exposure to the energy of the gas generated during the combustion of the powder charge in the barrel of the launcher (RU 2008048 C1, RU 2 055 767 C1, RU 189214 U1). The disadvantages of these devices are the low level of efficiency due to large losses of fire extinguishing agent on the way to the fire source due to dispersion in the air and settling outside the fire source, as well as insufficient delivery range of fire extinguishing substances.

Among the known means of delivery and spraying of substances in the fire center, the use of pyrotechnic (powder) gas sources is relevant. A device is known that provides for delivery by artillery pieces (US 7325350) or bombs in the form of a projectile (US 7896092). The device is thrown from a helicopter and is triggered by the heat generated by a burning building when it enters the fire. There are known delivery and spraying devices (SU 1729525 A1, RU 131977 U1, RU 113155 U1), which make it possible to increase the efficiency of fire extinguishing of high-rise buildings due to the precise delivery and spraying of fire extinguishing agents in the fire. The disadvantage of these inventions is the low efficiency of extinguishing fires. Low utilization rate of the OS in the very heart of the fire due to its removal from the hearth by hot air, evaporation or decomposition as a result of exposure to high temperatures. That is, the proportion of the extinguishing agent reaching the hottest zones of the fire, on which it is necessary to act as effectively as possible, is insignificant.

Close to the technical essence and the achieved results to the claimed invention is a method of fire extinguishing (options) and a device for its implementation according to US Pat. RF 2 288 761. The method consists of ejecting a plurality of projectiles containing OS through the muzzle of the barrel of an artillery-technical means; identification of the target area that needs to be covered by the OS, and the release of shells filled with the OS from the artillery and technical means, due to which the specified OS is dispersed over the target area; activation of the means of separation occurs on impact, due to which the OS can be dispersed at ground level or is activated after receiving a signal by projectiles, due to which the OS can be dispersed at a given height above ground level; activation of the specified means of separation is carried out with different predetermined time delays, due to which the OS can be dispersed at different heights above ground level.

However, according to the results of modeling heat exchange processes in case of undirected detonation over the fire source (as well as detonation in the fire source), it was calculated that for effective extinguishing of a fire of solid combustible materials, for example, forests, the specific consumption, for example, of powder OS for fire extinguishing by an undirected explosion should be about 2 , 5 kg / m2, and with a large area of combustion and unevenness of thermodynamic processes over the area of the fire - many times more. But even if we assume that the velocity head of the ascending heat fluxes will be overcome, then the effective extinguishing of a forest fire with an area of 10 hectares would require 500-600 tons of OS (in particular, powder). It is quite obvious that it is unrealistic to deliver so much powder to the fire at the same time. Simulation confirmed another fact that for effective extinguishing of a fire of solid combustible materials, the required powder concentration is about 0.5 kg / m ³ (i.e. 0.5 kg of powder per 1 m ^{3 of} the combustion zone), and the intensity of the powder supply is about 0 , 1 kg / (m ³ s) (i.e. per 1 m of combustion zone per second). Then, for effective extinguishing, the process of feeding the powder should last continuously for 5-10 s. According to the OC parameters, the average powder concentration is 5 times less than the required one by non-directional powder spray. The spraying process is unlikely to take 5-10 s, most likely 1 s or less, which cannot guarantee effective fire extinguishing. And the last - in the above conditions, to deliver the OS to the fire site, more than 20 aircraft with 100 bombs weighing 250 kg each would be required at the same time or the use of 2000 artillery installations with shells weighing 25 kg simultaneously. These data are valid for the case of extinguishing a forest fire with an area of only 10 hectares, but the size of the average fire in Russia exceeds 50-60 hectares, i.e. 5-6 times more. Thus, the technical implementation of this method (fire extinguishing process), taking into account the above arguments and economic parameters, prove its failure.

Designed and protected as a utility model by a patent. RF No. 113155, a method of fire extinguishing using a fire extinguishing device delivered to the fire by any known method. The device is a container with a fire extinguishing agent, closed at the ends of the front and back covers. For the purpose of prompt delivery, the release from the launcher is performed. The container has a spray of extinguishing composition made in the form of a cylindrical tube, closed at both ends, located in the front part of the container along its longitudinal axis. The device contains a charge of a powder pressure accumulator, a retarding charge and a Laval nozzle, with an expelling charge placed in the nozzle, placed in a common housing located in the rear of the container on the same axis with the atomizer, and the powder pressure accumulator adjoins the atomizer at the end ... The fire extinguishing method is implemented as follows. The prepared (filled) container is attached to the delivery vehicle. A discharge of electric current is supplied to the electric igniter, the expelling charge is ignited. The fire extinguishing device is fired from the launching device in the direction of the fire. When the expelling charge burns, the moderator charge is simultaneously ignited. After a predetermined time, the charge of the moderator ignites the charge of the powder pressure accumulator, the resulting gases penetrate into the sprayer tube, rupture it and mix with the fire extinguishing agent.Under the pressure, the container is destroyed, the fire extinguishing agent is sprayed in all directions.

The method of fire extinguishing according to this patent, as noted by the applicant, is distinguished by the efficiency and accuracy of delivery, and the container with the fire extinguishing composition provides an instant (impulse) release in a circular sphere of a highly effective fire extinguishing agent. By the essence of the implementation of the fire extinguishing process, by the totality of the implemented techniques, we consider this method to be the closest analogue of our proposed method.

The disadvantage of this method is that the device used to deliver the OS does not provide a targeted release of the OS, spraying it in a circular sphere, in all spatial directions from the point of explosion. This leads to a low specific concentration of the sprayed fire extinguishing powder and strong dispersion of the powder, which does not provide sufficient oxygen shut-off to the combustion zone. In addition, the dispersed particles of the atomized powder are heated and carried away by the ascending streams of combustion products. That is, the proportion of the extinguishing agent reaching the hottest zones of the fire, on which it is necessary to act as effectively as possible, is insignificant. This leads to the low efficiency of the device for extinguishing fires over a large area and high-intensity fires. In the case of non-directional contact firing (explosion), only a small part of the extinguishing composition will be delivered to the combustion center. Most of it will be scattered upward and sideways by the explosion, as well as carried away by powerful updrafts of combustion products. Indeed, if we imagine an ammunition with a fire extinguishing agent in the form of a ball (or cylinder) flying up to the target, then, according to the theory of a point explosion, all components, including the fire extinguishing agent, will be scattered over a spherical volume evenly in all directions. If we take the direction of the target to a solid angle of 60 degrees with the axis in the form of a tangent to the trajectory at the point of detonation, which is quite natural, since at large values of the angle, the distance to the target quickly grows (by 15% at an angle of spread of 60 degrees and by almost 50% at an angle of 90 degrees), and, as a result, the speed and concentration of the extinguishing agent rapidly decrease, after which it is easily carried away by powerful ascending flows of combustion products and does not reach the goal, then only 1/6 of the extinguishing agent will be involved in extinguishing the fire (60x6 = 360 degrees - the whole sphere).

The objective of the proposed technical solution is to develop a more effective method of fire extinguishing.

The solution to the problem is carried out by promptly delivering a fire extinguishing agent (projectile) to the fire site and using a fire extinguishing device that provides a directed powerful impulse release of this agent strictly to the target, as well as by the fact that the agent is activated after receiving a signal by the projectile, so that the OS can be dispersed at a given height above ground level, and with different specified time delays, so that the feedback can be dispersed at different heights above ground level.

Thus, the inventive method by pulsed fire extinguishing with a directed action of a fire extinguishing agent on a burning object has a number of advantages over similar non-directional devices that explode in the air above the hearth or upon contact with the hearth.

The task is achieved by the fact that in the inventive method of fire extinguishing, as a fire extinguishing device delivered to the identified fire site, a configurable device containing an OS and equipped with a system for its activation is used. The projectile contains a cylindrical body with a ballistic tip and a tail in the form of an inverse cone. The tail section can be equipped with an adapter. The ballistic tip is pressure-release capable. In the tail section, a remote fuse and an expelling charge in the form of a hinge of smoky gunpowder or any explosive are installed. Inside the cylindrical body there is a sleeve filled with OS, with a cover and a bottom and made with the possibility of longitudinal movement inside the body. The bottom of the liner abuts against the wad, behind which the expelling charge is located, and the liner cover contacts the ballistic tip and is also designed to be released under pressure. The movement of the liner with the OS is limited by stops symmetrically located in the cross section of the case, for example, in the form of screws screwed into the threaded holes of the projectile body, with the possibility of their installation at different distances from the bottom of the liner, which achieves control of the liner free travel, and, consequently, the kinetic the energy of the pulsed ejection of the OS during shock braking of the bottom of the sleeve against the stops. The method is carried out as follows.

The fire brigade directs the rangefinder to the target and measures the distance and height to it. Checking the firing table, he sets the required value of the flight time on the fuse, which is installed on the fire extinguishing projectile. The projectile is loaded, for example, in an RPG-7V and fired with a trigger. When the projectile approaches the target, the electric current from the remote fuse is transmitted to the spark plug, which ignites the expelling charge. After the ignition of the powder sample, powder gases are formed, which act on the bottom of the case through the wad and lead to the simultaneous ejection of the tip and the cap. At this time, the liner with the OS, which received an additional speed relative to the body from the expelling charge, strikes with force against the stops, throwing it out in the form of a torch. This achieves a complete impulse emptying of the liner cavity and imparting an additional speed to the entire fire-extinguishing composition strictly in the direction of the target, where it is sprayed in the form of a cone, which provides the required flow density to overcome the ascending flows and knock down the flame. The area of fire coverage depends on the opening height of the container (see table). Modeling has shown that a directed ejection at a given height in a sector defined by an angle of 60 ° requires 6 times fewer projectiles than with explosive non-directional throwing of an OS to obtain the same result.

The declared fire extinguishing projectile can be delivered to the fire zone in various ways: manually, mechanically, pneumatically, hydraulically, pyrotechnically, or by dropping or firing from top to bottom, by throwing from a helicopter (in case of extinguishing forest fires, oil spills, high-rise objects), for which it is necessary to dismantle the jet engine and install a stabilizing and fastening device using an adapter, or using multi-barreled rocket launchers and unmanned aerial vehicles.

The method can be applied to combat surface fires by multiple launching of multiple shells containing OCs using multiple launch rocket systems, resulting in an intense supply of OCs in the form of powerful squalls of a dispersed flow of a certain concentration and kinetic energy strictly in the direction of the target, the coverage area which depends on the opening height of the container (see table). Sprayed OS can be liquid, powder, gel. Any fire extinguishing agent can be used, for example, it is known (http://studopedia.net/4_16214_ognegasyashchie-sredstva.html) that the main extinguishing agents are water, chemical and air-mechanical foams, aqueous solutions of salts, inert and non-combustible gases , water vapor, halohydrocarbon extinguishing agents and dry extinguishing powders, in a gel or gaseous state, or produced by an aerosol generator. To increase the fire extinguishing effect of OS on objects located near the fire center, one fire extinguishing OS is replaced with another.

The claimed method is controlled by adjusting the length of the accelerating section of the sleeve by rearranging the stops along the length of the body, changing the mass of the expelling charge, changing the mass of the OS - changing the caliber and length of the container with the OS, setting the response time of the device. The effectiveness of the method increases if the area of the target area is divided into single sectors, determined by the area of the ellipse of technical dispersion of projectiles when they are fired from a separate installation for simultaneous exposure from different launchers at different installations of the sight, as a result of which the effectiveness of fire extinguishing of the entire target area is increased while reducing the consumption of projectiles ...

Thus, the inventive method of fire extinguishing ensures the delivery of the extinguishing agent to the target by almost 100% due to the absence of a scattering explosion.

Claims (2)

1. A method of fire extinguishing using a device containing a fire extinguishing agent and delivered in a known way to a fire source identified by the location and nature of the fire and providing a pulsed release of this substance onto a burning object due to the pressure of gases when the charge of the fuse is ignited, installed in the rear of the device and contacting with a fire extinguishing agent and an extinguishing charge, characterized in that a fire extinguishing projectile is used as a device containing a cylindrical sleeve with an agent fixed by stoppers, made in the form of a cylinder with a lid and a bottom, the type of fire extinguishing agent is set, its required amount and the caliber of the projectile are calculated for its placement , set the required value of the flight time on the fuse timer to ignite the expelling charge, adjust the free stroke length of the liner with the stoppers, which provides a given impulse release of the agent at the right time, set it on the means during delivery and a shot is carried out in the direction of the target, upon approaching which an electric current is supplied to the glow plug at a given time interval, while the expelling charge of the powder charge ignites, leading to the movement of the sleeve with the release of the tip and cover, followed by the impact of the bottom of the sleeve on the protrusions of the stoppers, providing impulsive ejection of the entire agent to the target proportional to the free travel of the sleeve. 2. A method according to claim 1, characterized in that the length of the sleeve stroke is set by moving the stoppers from its bottom, but not further than 2/3 of the sleeve length.