RU2584529C2 - Method and apparatus for containment peat fires - Google Patents

Abstract

FIELD: salvage operations.

SUBSTANCE: invention relates to localisation of peat fires. Method of localising peat fire consists in fact that in trench is set fire protection screen. Screen is made from silica fabric with underground and surface parts. Underground part of fire-protective screen is lowered into trench along far wall to make it uniform heat-insulating air gap. Projecting above soil surface (above-ground) part of fireproof screen prevents transfer smouldering peat grit through barrier strip. Proposed device for isolation of peat fires-fire-protective screen of multiple use. Screen is made from single-layer silica tissue maintaining temperature of not less than 1000 °C, lower part of the screen web is lowered into trench along the far wall to bottom, and protruding above soil surface part is performed with inserted, stitched on both sides, folds for insertion into them sharpened incombustible posts are secured vertically to ground surface and situates above it at least 0.4 m.

EFFECT: invention enables beforehand installation fireproof screen on propagation path of peat fire.

3 cl, 1 dwg

Description

The invention relates to the protection of forests from fires, in particular to the localization of peat fires.

A known method of combating fires on peatlands, including the creation of a barrier strip in the form of a trench to the depth of a peat deposit or to the level of groundwater and the laying of non-combustible material in it, which uses fire-resistant foam (AS USSR No. 1573104, class E02F 5 / 08, 1988).

The disadvantage of this method is the high consumption of fire-resistant foam, which fill the entire volume of the trench. The method is expensive and time-consuming, not allowing to exclude the flight of smoldering peat chips and other burning plant particles through the barrier strip.

A known method of combating fires on peatlands, which includes creating a barrier strip in the form of a trench to the depth of a peat deposit or to the level of groundwater and laying non-combustible material in it, using fire-resistant foam, whose bubbles instead of air contain exhaust gases from the fire engine engine (a S.S. USSR No. 36869, class A62C 27/30, 1970).

This method has the same disadvantages as the above method.

A known method of combating fires on peatlands, including creating a barrier strip in the form of a trench to the depth of a peat deposit or to the level of groundwater and laying moistened peat crumbs in it (RF Patent No. 2190441, class A62C 3/02, 2001).

The disadvantage of this method is its fragility, since the source of the peat fire, approaching the trench with moistened peat crumb, at a flameless burning temperature of peat 600-700 ° C, will quickly dry the latter, and the high saturation of the moistened mass of peat crumb with oxygen as a result of its preliminary grinding and mixing intensifies the process of burning peat crumbs in a trench. In addition, the trench with moistened peat crumb is not an obstacle for the flight of burning plant particles and smoldering peat crumb over the surface through the barrier strip. The method, like all the previous ones, does not allow the use of repeatedly non-combustible material in other fire hazardous areas.

A known method of combating fires on peatlands, including the creation of a barrier strip in the form of a trench to the depth of a peat deposit or to the level of groundwater and laying non-combustible material in it, which is used as a mixture of peat and underlying mineral soil extracted from a trench made to a depth of exceeding the thickness of peat by 50%. A mixture of peat with mineral soil is saturated with carbon dioxide (RF Patent No. 2472549, CL A62C 3/02, 2011).

The main disadvantage of this method is the inability of such a barrier strip to resist the transfer through it of smoldering peat chips and other burning plant particles. The method does not allow the use of repeatedly non-combustible material in other fire hazardous areas. The method is time consuming.

A known method of combating fires on peatlands, including the creation of a barrier strip in the form of a trench to the depth of a peat deposit or to the level of groundwater and the laying of non-combustible material in it, which is used as mineral soil (AS USSR No. 869779, class A62C 2 / 00, 1979).

The disadvantage of this method is the low efficiency of preventing the spread of the peat fire over the barrier strip due to the possibility of transferring smoldering peat chips and other burning plant particles through it. In addition, the method is time-consuming, since it requires, in addition to laying a trench, transporting and laying a large amount of expensive mineral soil into the trench, using special construction and transport equipment for this; the method eliminates the possibility of reuse of non-combustible material laid in the trench in other fire hazardous areas.

A known method of combating fires on peatlands, including the construction of a trench to the depth of a peat deposit or to the level of groundwater and the formation of a protective spatial barrier in it in the form of a wall or prefabricated elements of reinforced concrete slabs whose height exceeds the height of the trench, and the places of contact of the plates isolate and fill the resulting container is a liquid fire extinguishing agent (Patent RU 2213598 C1, class A62C 3/02, 2002).

The main differences of this method from the claimed are:

- the construction of the trench in this method is carried out along a straight trajectory according to the technology of installing barriers from reinforced concrete slabs in the trench. Reinforced concrete slabs do not allow to go around obstacles, because cannot fit into a trench laid along a curved path;

- the method includes the use of a liquid fire extinguishing agent, which is in relationship with the barrier of the plates. A liquid fire extinguishing agent, such as water, performs the main function of fire extinguishing and protective - protects the reinforced concrete slab from overheating and destruction. The use of a liquid fire extinguishing agent in the claimed invention is not required;

- this method does not provide for the technologically necessary formation of a heat-insulating air gap between the near wall of the trench and the barrier, the heat-air gap, which is formed when the plates are placed in the trench, is different or absent throughout the depth of the trench and accordingly does not perform the necessary heat-insulating function, as in the proposed method where an air gap is used that is identical over the entire area of the underground part of the fireproof screen, and the screen is lowered along the wall t farthest from the fire anshei. In addition, the barrier made of reinforced concrete slabs touches the near wall of the trench;

- in this method the minimum required height of the excess of reinforced concrete slabs over the trench is not indicated. If this height is insufficient, the smoldering peat crumb and other burning particles will fly through the trench and cause a further spread of the peat fire;

- the method is expensive, it involves building a road to the site of a peat fire, destroying obstacles, uprooting trees, installing reinforced concrete slabs with truck cranes and other heavy special equipment, which is not always possible and unsafe. The height of the reinforced concrete slabs is unknown and may be less than the height of the peat layer or insufficient for the minimum necessary height of the excess of the barrier over the trench. In this case, a further spread of the peat fire is possible. The method can be used repeatedly, but it also requires the use of heavy special equipment to extract and move reinforced concrete slabs in the area of a peat fire, which is associated not only with costs, but also with great risk.

Closest to the invention, the technical solution (prototype) of the method is a method of fighting fires on peatlands, which includes creating a barrier strip in the form of a narrow slit (up to 0.8 m wide) to the depth of the peat deposit or to the level of groundwater and filling it with engine exhaust gases fire engine. Fire-resistant quickly hardening foam is applied to the surface of the peat formation in the form of a roller covering the upper part of the gap (RF Patent No. 2191052, class A62C 3/02, 2001).

The disadvantage of this method is the significant consumption of costly flame retardant hardening foam. The method is time consuming. Cooled exhaust gases in a hollow gap, being heavier than air, sink to its bottom, diffusing beyond it, and oxygen-rich air that supports the combustion of peat is infiltrated from the soil into the formed space in the upper part of the gap. In addition, a roll of fire-resistant foam is not an obstacle to the passage of smoldering peat chips and other burning plant particles through the barrier strip. The method does not allow the use of repeatedly expensive flame retardant foam in other fire hazardous areas.

Known devices - peat trunks TS-1 and TS-2, perforated with holes that allow using a pump to pump water with a wetting agent evenly to the entire depth of the peat layer (TS-1 up to 1 m, TS-2 up to 2 m). To stop the peat fire, it is necessary to process a strip 0.7-0.8 m wide adjacent to the edge of the outbreak. To do this, create 2 rows of buried peat trunks, at a distance of 0.3-0.4 m from each other (Recommendations for the detection and suppression of forest fires // Collection of organizational and administrative documents for the protection of forests from fires. - M.: Federal Forest Service Russian economy, 1997. - 119 p.).

The disadvantages of this device is the low efficiency due to the fact that it requires a large flow of water with a wetting agent (40 l / min for each barrel). In this case, part of the supplied water goes to a depth. It is almost impossible to organize a water supply along the entire perimeter of peat fire centers, given the usual shortage of water in peat fires, the complexity of installing trunks and the need for a large number of pump pumps.

A device is known - a trencher for creating narrow slots in the soil, having removable equipment for closing the trench with a layer of soil with turf (A.S. USSR 111628, class E02F 5/06, 1957).

A disadvantage of the known device is the possibility of shedding peat from the walls of the trench and the transition of combustion through the trench. The device also does not allow to exclude the flight of smoldering peat chips and other burning plant particles through a trench from above.

The closest technical solution (prototype) for the device is a forest fire screen for localizing a forest fire (sectional fire wall) with vertical posts having tips, all of which are made of refractory material, characterized by height depending on the surrounding trees (Patent CN 202289267 U, 2012).

The main difference between this device and the claimed device according to claim 3 is that its design does not have an underground part and it is intended only for localization of ground (ground) forest fires, and not peat, it does not include a trench up to 1.2 m deep (the depth is determined by the typical parameters of trenchers), there is no heat-insulating air gap. In addition, the opposed device is a forest fire screen, consisting of 3 main elements - stands of refractory material; the fire-retardant part, and it is not specified which material is used, characterized by segments connected (overlapping) together and the dependence of the height on the surrounding trees; tips for deepening in the earth. Moreover, the height (width of the screen canvas) of the device is characterized by a dependence on the height of the surrounding trees, and in the claimed invention, the total width of the screen canvas is determined by the depth of the trench in combination with the width of the towering part of at least 0.4 m

The essence of the invention lies in the fact that to prevent the spread of the edge of the peat fire, a fire barrier is created in front of it, consisting of a narrow trench laid along any curved path to the depth of the peat to the mineral layer or to the groundwater level, fireproof screen made of silica fabric from underground and the aboveground part and the heat-insulating air gap of constant thickness between the near wall of the trench and the fireproof screen.

To localize a peat fire, a narrow trench (up to 80 cm wide) is laid in a layer of peat with a trencher. Two workers unwind and lower into the trench along its far wall the lower (underground) part of the fireproof screen weighted from below, the third worker fixes the part of the fireproof screen protruding above the soil surface (above ground) of at least 0.4 m in height in an upright position using advance the pointed non-combustible racks sewn into the screen by non-combustible threads.

The drawing shows a localization scheme of a peat fire fireproof screen. A fireproof screen 1 with a weighting agent 7 in its lower part 6 is secured by struts 2 in peat and lowered into a trench or slot 5, which separates the burning part of peat 3 from its non-burning part 8, to the level of groundwater or soil mineral layer 4.

The temperature of flameless burning (decay) of peat usually does not exceed 700 ° C. At the same time, the fireproof screen withstands the temperature of 1000 ° C for a long time and therefore can be used repeatedly.

The fireproof screen is a cloth of a single-layer silica fabric, while a weighting cord is sewn into the lower edge of the screen fabric to achieve full and quick lowering of the lower part of the fireproof screen to the bottom of the trench, and its upper part can be inserted into it with pointed non-combustible racks for fastening vertically to the surface of the soil and elevations above it, for example, with folds sewn on both sides for inserting racks into them.

Taking into account the fact that the depth of the trench can vary depending on the depth of the peat deposit, the width of the screen blade, lowered to the bottom of the trench, also varies. In this regard, racks must have an appropriate margin of length. For example, if the screen is designed for a maximum trench depth of 1.2 m (a typical maximum for trenchers), and at the same time rises 0.4 m above the trench, then with a trench depth of 0.6 m it will rise 1 m Then the minimum length of the rack, taking into account that it should be 0.2 m into peat, will be 1.2 m. To accelerate the deployment of the fireproof screen and lower it into the slot, its lower part is heavier, the weighted cord sewn into a non-combustible fabric is used , for example, in the manufacture of fishing nets for their quick burial fishing in the water.

A fireproof screen and uniform air gap in the trench isolate the peat layer behind them from the direct effects of fire, heat transfer by convection and radiation. Also, the fireproof screen eliminates the transfer of smoldering peat chips and other burning plant particles beyond the trench.

Installation of a fireproof screen along any curved path is 5-10 times faster than filling the trench with other non-combustible materials.

Given the low weight and durability of the fireproof screen, its installation can be carried out by two or three untrained manual workers.

The proposed method and device for its implementation allows for the early installation of a fireproof screen on the path of the spread of peat fire, as well as after the localization of the burning center, its multiple transfer and installation in other fire hazardous areas of peat bogs. At the same time, it is not necessary to enter personnel and special fire fighting equipment directly into the peat fire zone to eliminate it.

The simplicity, convenience, long-term, low cost and safe storage of the fireproof screen are additional advantages of its use for fighting peat fires.

Claims (3)

1. The method of localization of peat fires, which consists in the fact that in front of the spreading edge of the peat fire, a device is installed consisting of a narrow trench laid to a depth of peat to the mineral layer or to the level of groundwater and a fire shield, characterized in that the screen is made of silica tissue, with an underground and aboveground part, while its underground part descends into the trench along the far wall, providing the formation of a heat-insulating air gap between the near wall of the trench and gnezaschitnym screen and for insulation located over the device layer of peat from direct exposure to fire, heat transfer by convection and radiation and elevated part rises above the surface of the soil, ensuring the prevention of the transfer device through smoldering peat chips and other particulate burning plant. 2. A device for localizing peat fires includes a trench, a fireproof screen, characterized in that the screen is made of silica fabric that can withstand temperatures of at least 1000 ° C, while the lower part of the screen canvas with a width determined by the thickness of the peat layer is lowered into the trench along its far wall to the bottom so that the resulting air gap performs a heat-insulating function, and its upper part rises above the surface of the trench with non-combustible racks to a height of not less than 0.4 m. 3. The device according to claim 2, characterized in that in order to achieve a complete and rapid lowering of the lower part of the fireproof screen to the bottom of the trench, it is weighted, for example, by a weighting cord sewn into the lower part of the screen.

Images