Fluidization method and powder fire-extinguishing module

Abstract

The group of inventions relates to fire-fighting technology, and more particularly to a method for fluidizing a fire-extinguishing powder in a powder fire-extinguishing module and to a powder fire-extinguishing module. The method for fluidizing a fire-extinguishing powder includes pressurizing a module to a working pressure by means of combustion products formed during the combustion of a composite gas generator charge, then releasing the pressure in a pulsed manner, wherein a first stage of pressurization to a pressure equal to 0.1-0.5 of a working pressure is brought about by combustion products formed during the combustion of charges that burn up within a time period T1, and a second stage of pressurization is brought about by combustion products formed during the combustion of charges that burn up within a time period T2, where T1 is 3-4 times less than T2. The inventions can be used for protecting production, warehouse and domestic premises, automobile engine compartments and luggage compartments, heavy-duty, mining and agricultural machinery, as well as road vehicles and trailers, where a fire-extinguishing module may be subject to heavy working conditions (shaking and / or vibration). The technical result is that of allowing more efficient fire extinction as a result of the uniform and complete fluidization of the fire-extinguishing powder, even when compacted.

Description

[0001] METHOD OF PSEUDOLIQUEFACTION AND POWDER FIRE EXTINGUISHING MODULE

[0002] Field of technology

[0003] The group of inventions relates to fire-fighting equipment, namely to powder fire extinguishing modules (Ml 111), which can be used to protect production, storage and utility rooms, engine and luggage compartments of cars, heavy-duty, quarry, agricultural equipment and other road transport vehicles and trailers, where during their operation the fire extinguishing module can be subjected to high operational loads (shaking and / or vibration).

[0004] Long-term operation under normal conditions, as well as short-term use under severe operating conditions, leads to compaction of the fire extinguishing powder in the module and, as a consequence, blockage of the outlet openings of the sprayers and the impossibility of its exit from the module when triggered. In this regard, the issue of preparing the fire extinguishing powder for feeding for extinguishing, especially when used in transport, is very relevant.

[0005] Prior art

[0006] The use of powder fire extinguishers of the pumping type in transport is widely known; they are always ready for action due to the pre-created pressure in the fire extinguisher body (see, for example, URL: https: / / www.pogkomplekt.ru / prodl 1 ,htm). However, such devices, as vessels that are constantly under pressure, are subject to increased requirements: the presence of a pressure gauge; leakage control of no more than 10% per year of the operating pressure, the possibility of caking of the fire extinguishing powder, etc. In this regard, the most preferable for use in transport are fire extinguishers and / or modules equipped with a gas generator, since they have the following positive qualities: an increased warranty period of storage, no need to check the pressure in the housing, the effect of gaseous products on the fire extinguishing powder during the operation of the gas generator, which potentially increases the possibilities for its aeration (for example, RU50840 U1, 27.01.2006; RU 177480 U1, 26.02.2018, etc.).

[0007] A device for spraying powders is known from patent RU 2651433 C1, published on 19.04.2018 (prototype), which includes a cylindrical body containing powder, a gas generator with a solid fuel charge, a powder aeration system, and a nozzle for the outflow of a gas-powder mixture. The gas generator, made in the form of a separate unit, contains a nozzle and is installed coaxially with the body containing the powder. The charge, armored along the side surface, is made in the form of sequentially arranged alternating solid and channel disks of the same diameter made of solid fuel. A central hole is made in the channel disks, and a system of radial-concentric grooves is made on their end surface on the side opposite the gas generator nozzle. The powder aeration system is made in the form of a tube perforated along the side surface, installed along the axis of the body with the powder within its length. One end of the tube is plugged, and the other is connected by a gas duct to the nozzle of the gas generator.The perforations on the side surface of the tube are made tangentially in the form of alternating belts with the possibility of creating a flow of combustion products of the gas generator swirling in opposite directions.

[0008] The prototype also discloses a method for pseudo-fluidization of fire extinguishing powder in a powder fire extinguishing module with a gas generator, in which the module is pressurized to the operating pressure with subsequent pulsed release of said pressure. In this case, the pressurization is provided by pulsed pressure fluctuations in the gas generator and, consequently, fluctuations in the flow rate of combustion products in the module aeration system. In this case, combustion products are formed during combustion of a solid-fuel combined charge consisting of channel and solid disks made of the same solid-fuel composition. The cyclogram of the gas flow rate supplied to the powder aeration represents the operating mode (during combustion of a solid disk) with pulsations of increased flow rate superimposed on it (during joint combustion of a solid and channel disk).

[0009] The disadvantages of the prototype include the following:

[0010] - the complexity of manufacturing and assembling a combined charge, the complexity of the configuration of channel disks, high requirements for armoring the outer surface of a combined charge (ignition of the charge on the outer surface can lead to a catastrophic increase in pressure in the gas generator and destruction of the entire module);

[0011] - the requirement for a supercritical pressure difference on three consecutive minimum sections of the working medium flow path (gas generator nozzle, holes in the powder aeration system tube, gas-powder mixture outflow nozzle) leads to very high pressure in the gas generator, which increases the danger of using the module as a whole. Particularly high pressure in the gas generator and other module units is formed during the combined combustion of solid and channel disks (the pressure in the gas generator reaches 32.4 MPa (324 bar)).

[0012] - the labor intensity of making tangential holes in the powder aeration system tube, as well as the lack of sealing elements for these holes.

[0013] Disclosure of invention

[0014] The objective of the proposed group of inventions is to create a new module capable of operating effectively both under normal operating conditions (as part of stationary installations) and under difficult operating conditions that cause compaction or caking of fire extinguishing powder.

[0015] The technical result is an increase in the efficiency of fire extinguishing due to uniform and complete fluidization of the fire extinguishing powder, including compacted one.

[0016] To solve the problem and achieve a technical result, a group of inventions is proposed, including a method for fluidizing fire extinguishing powder and a powder fire extinguishing module.

[0017] The method of fluidization of fire extinguishing powder in a powder fire extinguishing module with a gas generator is carried out by pressurizing the module to the working pressure with combustion products formed during the combustion of the combined charge of the gas generator, followed by a pulsed release of the said pressure. In this case, the pressurization at the first stage is carried out to a pressure equal to 0.1 0.5 of the working pressure, with combustion products formed during the combustion of pellets that burn during the time t ь At the second stage, the pressurization is carried out using combustion products formed during the combustion of checkers, which burn during time t2, where T2 is 3-4 times less than t2.

[0018] The powder fire extinguishing module comprises a housing with a fire extinguishing powder, a release unit with a destructible membrane, a starting device with an initiating element, a gas generator including a housing with openings and a combined charge made of pellets and placed inside the housing. The gas generator is designed with the possibility of supercharging the module in two stages, wherein the combined charge of the gas generator contains pellets designed with the possibility of burning during to carry out the pressurization at the first stage, and the charges, made with the possibility of combustion in time t2, to carry out the pressurization at the second stage, where ii is 3-4 times less than t2. In this case, the charges of the combined charge, burning in time t ьare located in the gas generator body closer to the initiating element than the pellets that burn during time t2. The openings in the gas generator body are closed with a sealing membrane. The module additionally contains a diffuser connected to the gas generator body and installed between the gas generator and the exhaust unit.

[0019] Brief description of the drawings

[0020] The group of inventions is illustrated by a drawing.

[0021] The figure shows a general view of the powder fire extinguishing module in section.

[0022] Embodiments of the invention

[0023] The powder fire extinguishing module comprises a cylindrical or lenticular or spherical body 1 filled with fire extinguishing powder, a release unit 2 with a destructible membrane 3, a starting device 4 with an initiating element 5, a gas generator including a body 6 with openings 7, inside which a combined charge of solid fuel pellets (8, 9) is placed. The charge in the body 6 of the gas generator rests on a spacer insert 12, located in such a way that a tubular chamber 13 is formed in the lower part of the body 6 of the gas generator, which performs the function of an aerator. The pellets 8, burning during the time t ьare located in the body 6 of the gas generator on the side of the initiating element 5, wherein the charges 9, burning during the time t2, are placed after the charges 8, and the amount of the combined charge is sufficient to implement the method of pseudo-fluidizing the fire-extinguishing powder, carried out by means of a step-by-step pressurization of the module to the working pressure with combustion products formed during the combustion of the combined charge of the gas generator, with subsequent pulsed release of the said pressure. Moreover, the pressurization at the first stage is carried out to a pressure equal to 0.1 0.5 of the working pressure, with combustion products formed during the combustion of the charges 8, burning during the time Xi, at the second stage the pressurization is carried out with combustion products formed during the combustion of the charges 9, burning during the time t2, wherein TI is less than t2 by 3-4 times. A diffuser can be additionally installed inside the module, connected to the body 6 of the gas generator and installed between the gas generator and the release unit 2.The divider is a welded structure consisting of a bushing 10 and a ring 14 connected by ribs 15 in the form of plates (it can contain up to 12 ribs). The divider additionally divides the powder flow by its ribs 15 into several parts, since it takes on the pressure of the overlying powder layers. As a result, the coherence of the powder flow located under the divider falls, the initial shear resistance decreases, which helps prevent the formation of static arches above the outlet opening of the release unit 2 and creates favorable conditions for the powder flow. The divider also ensures unloading of the body 6 of the gas generator from bending and stretching forces.

[0024] The proposed design of the device was tested. A module with a cylindrical body and a capacity of 50.0 ± 2.5 l was selected for testing, since its body has a longer cylindrical section, which contributes to stronger compaction of the powder compared to modules with spherical or lenticular bodies. Vekson ABC-70 Module was used as the powder. In all tests, in order to simulate the effect of loads on the module during its operation on a vehicle, the powder was compacted by vibrating the module on a vibration table for 1 hour at a frequency of 50 Hz and an amplitude of 0.5..1.0 mm. Before and after vibration, the immersion depth of a cylindrical probe (penetrator) with a diameter of 3.8 mm into the powder was determined under the action of a weight force of 52.7 N. Before vibration compaction, the probe completely passed through the entire powder layer. After vibration, the probe stopped immersing into the powder at a certain depth. The depth of immersion of the probe was recorded.Combined charges were used, containing from 2 to 5 charges 8 of the GP-40u type composition (burning in time Ti) and from 16 to 25 charges 9 of the MGG-62 type composition (burning in time t2). All charges 8 of the GP-40u composition were located on the side of the initiating element 5. It was experimentally established that such a quantity of combined charge is sufficient for optimal fluidization of the powder in the tested module. As a result of the tests, it was established that the proposed module design initially ensures a rapid pressure build-up to a level equal to 0.1 0.5 of the working pressure (the pressure of opening of the destructible membrane 3 installed in the release unit 2), and then a relatively slow pressure rise until the membrane 3 opens. The dependence of the combustion time TI on T2 was established experimentally.When implementing the proposed method of pseudo-fluidization, rapid penetration of gas into the compacted powder mass and more complete saturation of the powder with gas are ensured, and when the membrane is opened and the pressure is abruptly released, gas expansion occurs, and, accordingly, the compacted powder mass is effectively destroyed in its entire volume.

[0025] The proposed device operates as follows.

[0026] The powder fire extinguishing module installed in a regular place does not have excess pressure inside the housing 1 in the standby mode. The module is triggered when voltage is supplied to the circuit of the starting device 4 from the fire extinguishing system. When a current pulse is supplied to the starting device 4, the combined charge pellets are ignited, the pellets 8 located on the side of the initiating element 5 burn out first, then the pellets 9 burn out, and gas is released. The gas passes through the openings 7 of the housing 6 of the gas generator. The increasing gas pressure leads to rupture (burning) of the sealing membranes 11, made, for example, from a heat-shrinkable polymer. A further increase in pressure promotes pseudo-fluidization of the fire extinguishing powder in the powder fire extinguishing module, which is carried out by pressurizing the module to the operating pressure with combustion products formed during the combustion of the combined charge of the gas generator, with a subsequent pulsed release of the said pressure.Moreover, at the first stage, the pressurization is carried out to a pressure equal to 0.1-0.5 of the working pressure, with combustion products formed during combustion of the charges 8, burning during the time T], at the second stage, the pressurization is carried out with combustion products formed during combustion of the charges 9, burning during the time t2, wherein T2 is 3-4 times less than t2. A further increase in pressure leads to the destruction of the membrane 3 installed in the release unit 2, and the supply of powder through the release unit 2 or through a guide pipeline (not shown) mounted on the release unit into the protected space.

[0027] The module is launched either forcibly or automatically when the fire extinguishing system detects initial signs of a fire.

Claims

Invention formula 1. A method for fluidizing a fire extinguishing powder in a powder fire extinguishing module with a gas generator by pressurizing the module to the operating pressure with combustion products formed during the combustion of a combined charge of the gas generator, followed by a pulsed release of said pressure, characterized in that the pressurization at the first stage is carried out to a pressure equal to 0.1-0.5 of the operating pressure, with combustion products formed during the combustion of pellets that burn during time T], and at the second stage the pressurization is carried out with combustion products formed during the combustion of pellets that burn during time t2, with t2 being 3-4 times less.

2. A powder fire extinguishing module comprising a housing with a fire extinguishing powder, a release unit with a destructible membrane, a starting device with an initiating element, a gas generator including a housing with openings and a combined charge made of pellets and placed inside the housing, characterized in that the gas generator is designed with the possibility of pressurizing the module in two stages, wherein the combined charge of the gas generator contains pellets designed with the possibility of burning in a time of t ь for carrying out supercharging at the first stage, and charges made with the possibility of combustion during time t2, for carrying out supercharging at the second stage, wherein ii is 3-4 times less than t2, and the charges of the combined charge, burning during time ii, are located in the body of the gas generator closer to the initiating element than the charges, burning during time t2.

3. The module according to item 2, characterized in that the openings in the gas generator body are closed by a sealing membrane.

4. The module according to paragraph 2 or 3, characterized in that it additionally contains a diffuser connected to the gas generator body and installed between the gas generator and the exhaust unit.

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