RU2444466C1 - Helicopter fire tank /versions/ - Google Patents

Abstract

FIELD: fire-prevention facilities.

SUBSTANCE: invention relates to aviation facilities for fire extinguishing and is designed to extinguish forest fires. The helicopter fire tank in the version of realisation comprises a reservoir, an inlet valve, several nozzles in its lower part, besides, nozzles are directed along the horizontal line to all sides, and along the vertical line a half of nozzles is directed upwards at the angle of 1-45° to the horizontal line, and the other half is directed horizontally or downwards at the angle of 1-30° to the vertical line. Nozzles are connected to the tank with one common or individual controllable valves. The fire tank may be equipped with nozzles of shower or centrifugal type, directed downwards, TV cameras, an aerodynamic stabiliser. In one of the versions the helicopter fire tank is arranged as fully tight and has a supercharging system and a valve that connects the tank cavity with atmosphere. In the other version the tank has a pipe directed downwards into the lower part, at the end of which there are nozzles installed. In the fourth version of realisation the tank has a vertical wind at the bottom, the centre of lifting force of which is on one vertical line with the centre of the tank gravity.

EFFECT: invention provides for higher efficiency of forest fires extinguishing.

9 cl, 3 dwg

Description

The invention relates to aviation fire extinguishing means and is intended mainly to extinguish forest fires.

Suspended helicopter fire tanks are known, see US Pat. Russia No. 1384526 or 2073624, however, they are designed to drop water vertically down. At the same time, even taking into account the translational speed of the helicopter, water droplets quickly decelerate in the atmosphere and fall almost vertically. And observations from above showed that in a projection from above, a forest without foliage (winter or burnt) is a circle of trunks with diverging branches. The area of trunks and branches is approximately 5% of the total area. That is, when discharged from above, only 5% of water falls on the trees, and almost no water enters the lateral surface of the trunk, which is the main source of combustion.

Also known is a hanging tank equipped with a hose for supplying water over a long distance, see US Pat. Russia №2096268. However, to extinguish forest fires, it is not necessary to supply water over long distances, since a helicopter can fly or hover directly above the source of ignition.

This tank in the lower part has several nozzles directed horizontally - in all directions, and vertically - half of the nozzles are alternately directed upward at an angle of 1-45 degrees to the horizontal, and the other half of nozzles are directed horizontally or downward at an angle of 1-30 degrees to the horizontal moreover, the nozzles are connected to the tank by one common or individually controlled valves. At the same time, about five times more water gets to the lateral surface of the trunks than when dumped from above. About the same amount of water falls on the branch, and about 20% less water falls on the ground than with a vertical discharge. That is, the same amount of water can extinguish about five times the large area of a horse’s fire.

Due to the circular arrangement of the nozzles, a strip of forest is watered with a width equal to twice the reach of the upper nozzles, in particular directly under the tank. However, for a more reliable spillage of the central combustion strip, the tank has one or more shower-type nozzles or an even number of centrifugal-type nozzles directed downward.

The tank should be kept as close to the tops of the trees as possible. You can even lightly touch them. To accurately maintain flight altitude, the tank is equipped with a rotary camera or several cameras that form an arc or circular view. Since the tank can get into the flames, the cameras should have thermal protection, and the lower 15-20 meters of the suspension should be a chain (s) made of heat-resistant steel.

At the same time, the pilot or co-pilot during the passage over the fire strip controls the helicopter using this video surveillance.

Since the tank is connected to the helicopter with a video cable and a cable or control hose, it is unacceptable for it to spin in flight. To prevent this, the tank is equipped with a simple aerodynamic stabilizer, which can be removable for ease of storage and transportation.

For a better distribution of water in the volume of the dome of the jets, the nozzles have oblong sections in the vertical or inclined direction, see Fig. 2.

The diameter of the dome of the jets should be slightly larger than the width of the combustion strip.

To give the jets sufficient speed, water must be supplied to the nozzles under pressure. For this, the tank must be airtight so that it can create excess air pressure, for example, taking it from the compressor stages of the helicopter’s gas turbine engine or from a separate compressor located in the helicopter.

As the water is consumed, the air pressure in the tank will decrease, therefore, in order to maintain an approximately constant diameter of the dome of the jets, the nozzle valves should be opened gradually.

This version of the tank allows you to use the accumulated internal pressure of air and water for quick and simultaneous pneumatic, and better - hydraulic drive of nozzle valves.

The desired water pressure in front of the nozzles can also be created hydrostatically. For this, the tank has a downward-directed pipe in the lower part, at the end of which nozzles and nozzles are located. The length of the pipe is determined by the required pressure. The diameter of the pipe is determined by the throughput of the nozzles. This option has its advantages and disadvantages. Advantages: it does not require complete tightness of the tank; it does not require a top cover and a valve that connects to the atmosphere. Disadvantages: storage and refueling of the tank becomes more difficult, it becomes almost impossible to refuel the tank by immersion in a natural or artificial reservoir, a powerful pneumatic, hydraulic or electric drive is required to simultaneously turn on the nozzle valves.

If the fire is accompanied by wind, then the helicopter can carry the tank over the strip of fire, not flying in a smoky area with high temperature and low oxygen content. The latter can lead to a sharp drop in power or to engine failure, as well as to a sharp decrease in the lift of the rotor due to lower air density. In calm weather, a helicopter cannot fly over a strip of fire without flying into a smoky area.

In order to extinguish fires in calm weather, the tank has a top, and if it is equipped with a downward-directed pipe, then a vertical wing located at an angle to the longitudinal axis of the aerodynamic stabilizer from the bottom, and the center of the wing’s lifting force lies on the same vertical axis as the tank’s center of gravity . Then, when flying at a sufficient horizontal speed, a tank suspended on a cable of sufficient length will deviate sideways from the flight path of the helicopter. In this case, the helicopter can carry the tank over the fire strip, not flying into the smoky area.

The wing should be attached to the suspension cable (s). Due to the low speed, the wing can be as lightweight as possible, in particular with heat-resistant fabric sheathing. Or the suspension should be attached to the wing (if it is strong enough).

Since the wing is only required in calm, it can be removable.

Figure 1 shows a tank consisting of a sealed container 1, which is a combination of a cylinder and conical ends. At the bottom of the tank there is an inlet valve in the form of an inward opening hatch 2 for refueling by immersion. In the manhole cover there is a shower nozzle 3, which is turned on by a valve 4 with a hydraulic actuator operating on water. At the bottom of the tank there are thirty-two nozzles 5 equipped with valves 4. Half of the nozzles are directed downward at an angle of 5%, half upward at an angle of 10 degrees. The nozzles in cross section have the form shown in figure 2. In the upper part of the tank there is a valve 6 connecting the tank cavity with the atmosphere when refueling by immersion. Its air drive can be combined with the air drive of the hatch. The tank is equipped with an aerodynamic stabilizer 7 (figure 3).

Figure 3 shows the tank in operation. The flowing jets form two domes and a downward-directed cone from the shower nozzle 3.

The tank works like this: it is carried by helicopter over the fire strip, and all the trees, except those located on the very edge of the reach of nozzles, pour from the side from two directions, with 71% of the width of the watering strip wetting the entire side surface of tree trunks. And in the remaining 29%, partial wetting occurs, but the flame is still extinguished by the resulting steam cushion.

Claims (9)

1. Helicopter fire tank, consisting of a tank and an intake valve, characterized in that it has several nozzles in the lower part, horizontally directed in all directions, and vertically half of the nozzles are alternately directed upward at an angle of 1-45 ° to the horizontal, and the other half of the nozzles are directed horizontally or downward at an angle of 1-30 ° to the horizontal, and the nozzles are connected to the tank by one common or individually controlled valves. 2. The tank according to claim 1, characterized in that it has one or more shower nozzles or an even number of centrifugal nozzles directed downward. 3. The tank according to claim 1, characterized in that it is equipped with a rotary camera or several cameras, forming a circular view. 4. The tank according to claim 1, characterized in that it is equipped with an aerodynamic stabilizer. 5. The tank according to claim 1, characterized in that the nozzles have an oblong section in the vertical or inclined direction. 6. A helicopter fire tank, consisting of a tank and an intake valve, characterized in that the tank is completely tight, has a boost system and has a valve in the upper part connecting the tank cavity with the atmosphere. 7. Helicopter fire tank, consisting of a tank and an intake valve, characterized in that it has a downwardly directed pipe at the bottom of which a nozzle is located. 8. A helicopter fire tank, consisting of a tank and an intake valve, characterized in that it has a top wing, and if it is equipped with a downward pointing pipe, then a vertical wing located at an angle to the longitudinal axis of the aerodynamic stabilizer, and the center of the wing’s lifting force lies on one vertical axis with the center of gravity of the tank. 9. Tank according to claim 8, characterized in that the wing is removable.

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