RU74461U1 - AEROSOL GENERATOR AND SMOKE CHIMNEY FOR HIM - Google Patents

Abstract

A group of utility models connected by a single inventive concept relates to smoke generating means that distribute the aerosol generated during the combustion of a pyrotechnic composition, which is used to form a smoke mask. The aerosol generator contains placed in the closed end cap and bottom cylindrical body, pyrotechnic checkers distributed around the perimeter and fixed on the bottom, between which a receiver gas outlet is formed, communicating with the outlet, and an igniter device New is that stiffeners in the form are made on the body zigs, pyrotechnic checkers are pressed into bearing shells, the outer diameter of which exceeds the inner diameter by 13-16%, and the bottom part of the checkers made of inert of the composition, is fixed in the layer of the polymer compound, the outlet is closed with a pressure reducing valve, and the bottom is fitted with a slide gate for the drowning communication windows made in a metal capsule filled with a wad of heat-insulating material, inside of which a powder charge is placed, and the igniter is located above one of the pyrotechnic checkers , in the open ends of which igniter tablets are installed. Another feature of the aerosol generator is that its smoke bomb, made of a metal chloride composition based on hexachloroethane with dispersed metal fuel powder, including zinc oxide, is technologically structured with fluororubber and additionally includes a disintegrant, which is used as carbamide or azodicarbonamide, in the following ratio of components, wt.%:

hexachloroethane 57-63 aluminum powder magnesium alloy 5-7 zinc oxide 23-27 fluororubber 3-5 urea or azodicarbonamide 4-6.

Technical solutions provided a new quality to the aerosol generator - stable buoyancy when dropped from watercraft into water, while retaining the functionality for setting a smoke screen with increased masking ability with stable flameless burning of modified composition checkers that provide stable combustion at low smoke generation rates.

Description

A group of utility models connected by a single inventive concept relates to smoke generating means that distribute the aerosol generated during the combustion of a pyrotechnic composition, which is used to form a smoke mask.

The level of this technical field is characterized by an aerosol generator (a device for volumetric aerosol fire extinguishing) according to the patent RU 2164808, А62С 13/22, 1999, containing an ignition unit for igniting the pieces of a pyrotechnic composition installed with a gap in a metal case with a bottom and axially aligned with perforated the receiver.

The cylindrical housing is equipped with communication openings (perforations) of the message with a reversible annular channel of the casing, closed with a cover with outlet openings.

This structurally compact aerosol generator is characterized by the fact that a tubular heat exchanger is mounted coaxially to the body, including a shell of gypsum and a perforated metal pipe that forms a reversible annular channel.

The disadvantage of the described design is the unsatisfactory dynamics of aerosol generation during end-face combustion of the pyrotechnic checker, the composition of the components (wt.%): 70 potassium nitrate, 19 dicyan-diamide and 11 iditol (combustible binder).

The end-face burning rate of the aerosol-forming checkers of this compacted pyrotechnic composition does not exceed 0.3 mm / s, which is clearly not enough for placing a smoke screen in a combat environment.

More perfect is the aerosol generator described in the invention according to patent RU2108824, А62С 13/22, 1998, which, for most of the matching features, is chosen as the closest analogue to the proposed one.

The known generator contains housed in a casing, coaxially mounted perforated housing and a Central tubular gas outlet in the reversing channel, the receiver and the outlet in the form of an annular nozzle.

The casing from the ends is closed by the bottom and the lid, in which the ignition unit of the pyrotechnic blocks mounted on the bottom and distributed in the annular gap between the body and the central tubular gas outlet is installed.

This design is characterized by the dynamism of aerosol generation during intense burning of a pyrotechnic charge along the developed surface of autonomous checkers.

In the reversing channel, spark-gas quenching and cooling of the gas-aerosol stream occur, which uniformly flows out through the annular nozzle covering the casing.

In the known generator, multistage cooling of the generated aerosol is constructively provided, which is additionally diluted with gaseous products of exothermic decomposition of the ablative material of heat-protective layers.

However, a continuation of the advantages are inherent disadvantages. So, it does not seem practically possible to use the well-known aerosol generator as a floating means for setting the smoke screen to ships because of its poor stability, aggravated by the downward direction of the outlet (towards the water), while it is open and communicates with the internal volume of the device where it is located burning pyrotechnic checkers.

This implies a narrowly limited area of target use and low functional reliability when used as a floating generator, discharged into the water from the side of the craft.

To generate saturated white or gray smoke, pyrotechnic compositions containing hexachloroethane, metal fuel powder and zinc oxide as an aerosolizer are known: patents DE 1542020, cl. 78d, 1972 and US 3485171, nat.cl. 102-56, 1967. The quantitative content of these components (wt.%) Are given in table 1 below.

Table 1 Component Mass content,% DE 1542020 US patent 3485171 hexachloroethane 40-60 45.5 Metal fuel powder: aluminum 1-10 7 zinc 20-30 - zinc oxide 2-10 47.5

The disadvantages of these pyrotechnic compositions include unstable combustion in a compacted state (pressed pieces), which limits the practical use of aerosol in small smoke-generating smoke generators, as well as low-tech in serial production of pyrotechnic pieces due to significant dusting during mixing of components and processing compounds, which is unsafe.

The masking ability of these formulations does not exceed 3.8 m ² / g.

The task to which the group of utility models is directed is to expand the field of use of the aerosol generator, its technological capabilities for use in a new quality, increase its functional reliability and improve the destination.

The required technical result is achieved by the fact that in the known aerosol generator, comprising pyrotechnic checkers distributed around the perimeter and fixed on the bottom and placed on the bottom of the lid and the bottom of the cylindrical housing, between which a gas outlet of the receiver communicating with the outlet is formed and an igniter proposal of the authors, stiffening ribs in the form of zigs are made on the body, pyrotechnic checkers are pressed into bearing shells, the outer diameter of which exceeds the inner the diameter is 13-16%, and the bottom part of the checkers, made of an inert composition, is fixed in the polymer compound layer, the outlet is closed by a pressure reducing valve, and the slide gate of the flooding communication windows mounted in a metal capsule filled with a wad of heat-insulating material is mounted on the bottom, inside of which a powder charge is placed, the igniter device being located above one of the pyrotechnic blocks, in the open ends of which igniter tablets are installed.

Another feature of the aerosol generator is that its smoke bomb, made of a metal chloride composition based on hexachloroethane with dispersed metal fuel powder, including zinc oxide, is technologically structured with fluororubber and additionally includes a disintegrant, which is used as carbamide or azodicarbonamide, in the following ratio of components, wt.%:

hexachloroethane 57-63

aluminum powder

magnesium alloy 5-7 zinc oxide 23-27 fluororubber 3-5

urea or

azodicarbonamide 4-6.

Distinctive features have provided a new quality to the aerosol generator - stable buoyancy when dropped from watercraft into water, while retaining the functionality for setting a smoke screen of increased masking ability with stable flameless burning of modified composition checkers that provide stable combustion at low smoke generation rates.

This practically makes it possible to reach the regime of burning pyrotechnic pieces weighing 36 kg in 5 seconds, with an aerosol formation time of at least 20 minutes. create a smoke screen with a height of 15 m over a length of at least 100 m.

The masking ability of the created smoke screen in the visible region of optical radiation, in the wavelength range of 0.40-1.56 μm, is increased to 4.5 m ² / g.

Improved destination indicators make it possible to use the proposed aerosol generator with modernized pyrotechnic checkers for setting camouflage curtains to protect the objects of the Navy, as well as simulating heavy ships for optoelectronic systems for enemy long-range reconnaissance.

An additional technical effect is the possibility of using an aerosol generator for smoke protection of coastal fleet facilities.

In addition, the flameless combustion of the aerosol-forming checkers of the generator allows its operation directly from the deck of the ship to distort its dimensions.

The execution on the generator body of stiffening ribs in the form of radial zigs, in addition to the main purpose, perform the functions of gas-dynamic shutters, restricting the distribution of gaseous products of combustion of pyrotechnic checkers peripherally outside the central gas outlet to the receiver. This stabilizes the gas-dynamic process of supplying the generated aerosol to the outlet and protects the housing from the damaging effects of streamlined hot combustion products of the checkers.

The implementation of the thick-walled load-bearing shells makes it possible to form aerosol-forming checkers by direct compression of the pyrotechnic composition and to produce this functional assembly in the form of an autonomous generator component.

The optimized ratio of shell diameters determines the functional thickness of its wall.

In the case when the outer diameter of the shell exceeds its inner diameter of less than 13%, burnouts of a relatively thin wall are possible, which leads to inevitable violations of the stationary mode of end combustion, as a result of which pressure inside the generator increases, which destroys the structure. In this case, the generator becomes non-functional.

With the indicated ratio of the shell diameters, when the excess is more than 16%, the ballast mass of thick-walled shells increases, the volume of the generated aerosol and, consequently, the masking ability of the smoke curtain decreases markedly.

Placing the bottom part of the checkers of a layer of inert composition is guaranteed to prevent unauthorized breakthrough of hot gaseous products of combustion to the pyrotechnic composition from below. The inert composition, which performs the function of booking the functional pyrotechnic composition of the checker, is pressed to the latter and, together with the polymer compound, serves as an insulating layer that blocks direct contact with the thermal energy of the generated aerosol.

In this case, a layer of polymer compound, which polymerizes during technological time, serves as a structural element for attaching shells, where pyrotechnic blocks are mounted.

Equipping the outlet with a pressure reducing valve ensures that its spring-loaded valve opens automatically when the receiver reaches the set threshold of excessive pressure of the gaseous products of combustion of pyrotechnic checkers for the dynamic discharge of the generated aerosol into the atmosphere.

The installation in the bottom of the casing, contrary to the receiver, of a metal capsule having communication windows with the cavity of the generator, provides the possibility of its sinking after the end of the aerosol-forming checkers.

The implementation of a metal sinking capsule, which acts as a convector for transferring the energy of hot combustion products of pyrotechnic pieces to a powder charge mounted inside a heat-insulating wad (from asbestos or cardboard layers), allows you to set the time delay to reach the ignition temperature of the executive powder charge.

This device performs the functions of the slide gate valve of the flooding valve, blocking the communication windows, eliminating the unauthorized ingress of moisture into the generator during storage and, especially, as intended.

The placement of a powder charge sensitive to thermal energy inside the flushing valve is designed to knock out its flaps when a predetermined temperature level is reached.

Placing the ignition device directly above one of the pyrotechnic blocks, in the open ends of which ignition tablets sensitive to the heat pulse are installed, ensures the unhindered propagation of the initiating heat pulse from the trigger, manual (shock) or electric.

SKF-32 brand fluororubber as a binder technological additive in the pyrotechnic composition (in the form of a 25% solution in acetone) eliminates dusting when the components are mixed and provides the required mechanical and physico-chemical stability of the pieces formed from it under sealing under operating conditions.

The introduction of fluorine rubber containing fluorine and 35 wt.% Chlorine, which are additional active oxidizing agents, into the structure of the pyrotechnic composition of smoke bombs, activates and stabilizes the process of smoke formation due to the formation of metal fluorides and chloride.

An additional inclusion of porophore smoke bombs in the structure of smoke bombs is aimed at increasing the gas outlet due to its decomposition with heat absorption and reducing slag formation due to the removal of the dispersion phase by gaseous combustion products.

In this case, the burning rate decreases and the aerosol formation time, i.e., the lifetime of the smoke screen, increases.

When the content of hexachloroethane in the pyrotechnic composition of the checkers is less than 57 wt.%, Incomplete combustion of the composition occurs, which reduces the performance.

When the content of hexachloroethane in the pyrotechnic composition of the checkers is more than 63 wt.%, The burning rate increases, which leads to the burning of soot and a decrease in the masking ability of the smoke curtain.

The use of aluminum-magnesium alloy powder provides physico-chemical stability for a long storage time of the composition, and functionally gives an increase in smoke formation.

Separate use of magnesium powder, active fuel. It leads to the formation of oxide and, as a consequence, to a decrease in prescription indicators.

Separate use of aluminum powder, a low-level fuel, leads to self-extinguishing of combustion and increases flake formation.

The use of this high-calorie metallic fuel can increase the combustion temperature of the composition and, accordingly, the content and completeness of chlorination in the dispersed phase of zinc oxide.

When the content of the aluminum-magnesium alloy powder is more than 7 wt.%, Flame combustion occurs, without the formation of the required amount of smoke for an effective masking curtain.

When the content of the aluminum-magnesium alloy powder is less than 5 wt.%, The combustion temperature of the drafts is insufficient to heat an inert zinc oxide, which reactively generates zinc chlorides - a smoke-forming component.

Zinc oxide is used to increase smoke formation and the masking ability of the smoke cloud due to the formation of zinc chloride.

With a content of zinc oxide of less than 23 wt.%, Unsatisfactory smoke formation occurs, and with a content of more than 27 wt.%, The burning rate of the composition decreases because the oxidizer does not contain enough chlorine to form metal chlorides. In the latter case, the composition is spent on the formation of ballast slag, which block the removal of the dispersion phase.

Fluoroelastomer serves as a combustible binder and a technological additive for component mixing operations, increasing their adhesive bonds, increasing the mechanical strength of pressed blocks, which, when used, improves their flammability, eliminates the dusting of components in the composition bag, which ensures the explosion safety of the process.

When the fluororubber content is less than 3 wt.%, The necessary or sufficient flowability of the prepared mixture is not ensured due to the uneven distribution in volume, that is, the mixture is not technologically advanced for mass production.

When the fluororubber content is more than 5 wt.%, The prepared mixture has a high humidity, which increases the technological drying time. The burning rate of the pieces from this composition decreases due to a decrease in mass flow per unit time, which reduces the masking ability of the smoke screen.

When burning a smoke composition having an excess of fuel, slags are formed that impede the sublimation of the smoke generator. To give the slag a looser structure and to facilitate the exit of the smoke generator into the aerosol, a baking powder is introduced into the composition, which improves the dispersion of the combustion products and the smoke generator.

Moreover, to reduce the temperature of combustion and dilution of gaseous products of combustion with inert products, in order to exclude combustion due to atmospheric oxygen, a flame arrester must be introduced into the composition.

In the used pyrotechnic composition of aerosol-forming blocks, organic matter is decomposed, which decomposes with the absorption of heat and the formation of a large number of inert and inactive gaseous products, that is, a disintegrant and simultaneously a flame arrestor are carbamide or azodicarbonamide.

When carbamide or azodicarbonamide is introduced into the pyrotechnic composition, less than 4 wt.% During the burning of the drafts, an increased amount of slag is formed that impedes the sublimation of the smoke generator, and the dispersion phase is reduced, which affects the masking ability of the smoke curtain.

A content in the composition of urea or azodicarbonamide of more than 6 wt.% Is ballast, since there is no noticeable improvement in prescription due to a decrease in the content of functional components.

Therefore, each essential feature is necessary, and their combination is sufficient to achieve a novelty of quality that is not inherent in signs of disunity, that is, the technical problem is solved not by the sum of the effects, but by a new super-effect of the sum of the attributes.

The patent search and comparative analysis with the identified analogues made it possible to conclude that the criteria for patentability of the proposed technical solution are met, because it is not known from the prior art, does not explicitly follow for a pyrotechnic specialist, and can be mass-produced according to the developed technical documentation.

The essence of the proposed utility models is illustrated in the drawing, which shows:

figure 1 - the proposed generator, a longitudinal section;

figure 2 - flooding valve.

The aerosol generator comprises a cylindrical body 1 of sheet metal equipped with stiffening ribs in the form of zigs 2 distributed in height.

The ends of the housing 1 are closed by a cover 3 and a bottom 4, rolled into a castle connection.

On the bottom 4, by means of a layer 5 of a polymer compound, thick-walled cylindrical shells 6 are fixed in which smoke bombs 7 of a pyrotechnic composition are pressed in.

The wall thickness of the shells 6 is selected from the condition of the minimum mass of material to guarantee the elimination of burnouts that could violate the specified combustion mode of the checkers 7 with the creation of gaseous combustion products above the critical pressure inside the generator. The wall thickness of the shell 6 is limited by the generatrix of the cylindrical surfaces, the outer diameter of which exceeds the inner diameter (diameter of the block 7) by 13-16%.

The shells 6 are equally distributed around the periphery of the housing 1, shaping the central gas outlet 8 of the receiver 9 located in the upper part of the generator, under the cover 3, which ensures the axial displacement of the center of mass downwards, which is necessary for the buoyancy of the generator with the guaranteed location of the outlet 10 in the cover 3 above the water surface , the level of his immersion.

The center of mass of the generator is located below its metacentre, which ensures a stable position in the water of the floating generator.

In the outlet 10 of the cover 3, a pressure reducing valve 11 is mounted.

In the lid 3 is installed a standard igniter device 12 of double action: mechanical shock and electric, which is located above one of the checkers 7.

From the open end of the checkers 7, igniter tablets 13 are installed, which are sensitive to the heat pulse from the triggered igniter device 12.

The bottom end of the checkers 7 is made of an inert composition 14 to prevent unauthorized ignition from the bottom of the hot combustion products.

Checkers 7 are made by sealing a pyrotechnic mixture of components in a shell 6 prepared according to the following regulations.

Hexachloroethane, aluminum-magnesium alloy powder, BTs-0 or BTs-1 zinc whites, and urea (or azodicarbonamide) in the above mass amounts are loaded into the mixer and mixed for 10-15 minutes.

Then add a 25% solution of SKF-32 fluororubber in acetone and mix for 15 minutes, during the last 5-10 minutes, compressed air with a pressure of 0.1 MPa is fed into the mixer.

Next, the mixture is granulated through a sieve of 1.6-2.0 mm and dried on trays for at least 6 hours to a moisture content of not more than 0.5%.

The prepared composition is characterized by a sensitivity to friction of 14 cells, to shock - 16 cells, sensitivity to an electric spark is low.

In the bottom 4 is fixed a metal capsule 15 with switching windows 16 for flooding, covered by a slide gate 17 (Fig. 2).

The capsule 15 is filled with a multilayer asbestos wad 18, inside of which a powder charge is placed 19. The described design performs the functions of an automatic flooding valve that is activated when the pyrotechnic composition of the checkers 7 burns out.

The optimized quantitative composition of the proposed pyrotechnic composition for pressing aerosol forming blocks 7 of the generator was calculated according to the mathematical model of the experimental design and tested in prototypes of products.

Typical compositions with an average content of components of an optimized quantitative range, at its borders and beyond, are presented in Table 2.

table 2 Components Mass content (%) in the compositions one 2 3 four 5 Hexachlretan 55 57 60 63 65 Aluminum Magnesium Alloy Powder 8 5 6 7 four zinc oxide (zinc white) 28 27 25 23 22 Fluoroelastomer * 2 5 four 3 6 Carbamide or azodicarbonamide 7 6 5 four 3 • - in terms of dry matter

Obtained as a result of testing prototypes of aerosol-forming checkers 7 in the composition of the generator of the proposed design, the destination indicators, the main technical characteristics are summarized in Table 3.

Table 3 PARAMETER The quantitative content in the compositions one 2 3 four 5 Burning rate, mm / s 0.1 0.18 0.2 0.2 0.1 Masking ability, m ² / g 2,5 4,5 4,5 4,5 3.0 Smoke generating ability,% 75 96 98 96 75 The content of slag,% 25 four 2 four 25 Nature of burning * Steady, flameless ** Checkers working time, min. 40 twenty twenty twenty 45 * - unstable, pulsating
** - unstable, pulsating with flashes of flame

The aerosol generator operates as follows.

For mechanical start, the shock mechanism is preliminarily cocked (not shown conditionally) and then the igniter capsule of the igniter 12 is punctured by the force of the flame igniting its amplifying powder charge, initiating the operation of the ignition tablets 13 of the adjacent checkers 7.

The thermal energy of the burning tablets 13 is sufficient to directly ignite the pyrotechnic composition of the checkers 7 and ignite the tablets 13 in the remaining checkers 7, which light up almost instantly.

The igniter capsule of the device 12 is also triggered by an electric pulse to start the generator.

Further, the sequence of interaction of structural elements is similar to that described above.

The gaseous products of combustion of the checkers 7 fill the gas outlet 8 and the receiver 9, where they accumulate and mix, while the temperature and pressure are equalized.

Upon reaching the set pressure level, the gaseous products of combustion squeeze the spring-loaded damper of the throttle valve 11 and are radially released into the atmosphere, actively forming a dense smoke screen.

When the checkers 7 are burned inside the heated capsule 15, the temperature rises to the level when the powder charge is ignited 19. The increasing pressure of the powder gases inside the capsule 15 kicks off the wad 18 and the slide gate 17, freeing the communication windows 16 immersed in water.

The water of the reservoir through the open windows 16 after the end of smoke generation, when the pressure inside the generator drops, enters the inside of the generator, filling the free volume for a period of not more than 10 minutes, as a result of which the spent aerosol generator is flooded.

For the formation of a smoke screen of a given size, several generators are used, ignited and discharged into water in a certain sequence.

Field tests of the proposed aerosol generator equipped with a modernized pyrotechnic checker showed high efficiency in the mobile production of a smoke curtain with enhanced masking properties.

Experimentally obtained, as a result of field tests, confirmation of the achieved improvement in the purpose indicators, the stability of operation and the expansion of technological capabilities, the new design and configuration of the pyrotechnic blocks of the aerosol generator allows us to recommend them for state testing, with the aim of putting the Fleet into service.

Claims (3)

1. An aerosol generator, comprising pyrotechnic checkers distributed around the perimeter and secured to the bottom of a pyrotechnic checker placed in a closed at the ends of the lid and the bottom of the cylindrical body, between which a gas outlet of the receiver in communication with the outlet is formed, and an igniter device, characterized in that stiffeners are made on the body in the form of radial zigs, pyrotechnic pieces are pressed into bearing shells, the outer diameter of which exceeds the inner diameter by 13-16%, and the bottom part of the pieces made I of inert composition, secured in the layer of polymer compound, an outlet relief valve is closed, and is mounted in the bottom of the sliding valve sinking communication windows formed in the metal capsule filled with a wad of thermal insulation material, inside which the powder charge is placed. 2. The aerosol generator according to claim 1, characterized in that the igniter device is located above one of the pyrotechnic blocks, in the open ends of which igniter tablets are installed. 3. Smoke bomb for an aerosol generator made of a metal chloride composition based on hexachloroethane with a metal fuel powder including zinc oxide, characterized in that it is technologically structured with fluororubber and additionally includes a disintegrant, which is used as carbamide or azodicarbonamide, in the following ratio of components, wt.%: hexachloroethane 57-63 aluminum powder magnesium alloy 5-7 zinc oxide 23-27 fluororubber 3-5 carbamide or azodicarbonamide 4-6