RU2350590C1 - Pyrotechnical smoke-forming composition - Google Patents

Abstract

FIELD: blasting.

SUBSTANCE: pyrotechnical smoke-forming composition contains potassium chlorate, anthracene, activators of burning - thiourea and phenol formaldehyde resin.

EFFECT: increased efficiency of smoke forming and masking ability due to increased rate of composition burning and increase of gaseous burning products.

2 tbl

Description

The invention relates to pyrotechnic compositions, during combustion of which an aerosol is generated, forming a smoke screen used for setting signals or false targets, as well as target designation.

The level of this technical field characterizes the composition of black smoke based on potassium chlorate (Bertoletova salt), including anthracene (hydrocarbon), which are contained in a mass ratio of 52/48 (see, for example, A.A.Shidlovsky "Fundamentals of pyrotechnics", M. Engineering, 1973, p.249).

This composition in essence and the number of matching features with the proposed one is selected as the closest analogue. A feature of the described mixture is a high content of potassium chlorate, which provides a rather high combustion temperature of the composition at which not sublimation of anthracene occurs, but incomplete combustion with the release of a large amount of soot, necessary for coloring the smoke.

However, the known composition has several disadvantages that limit its practical use in smoke-forming products, such as:

- low smoke generating ability due to the relatively low content of gaseous substances in the combustion products;

- a relatively low burning rate of the composition (0.6-0.7 mm / s), which reduces the dynamics of the formation of the smokescreen and is the reason for the increase in charge mass and dimensions of the structure;

- low technology in the manufacture and processing due to dusting of dry components, which makes the production explosive.

In addition, a pressed charge from a known composition burns poorly, and many slags are formed from excess anthracene, which determines unsatisfactory functional reliability and low smoke generation efficiency.

The problem to which the present invention is directed, is to increase the functional reliability and effectiveness of the intended use of a more technologically advanced smoke-generating composition.

The required technical result is achieved by the fact that the known pyrotechnic smoke-generating composition containing potassium chlorate and anthracene, according to the invention, further includes combustion activators - thiourea and phenol-formaldehyde resin, while the components are contained in the following ratio, wt.%:

potassium chlorate 52-55 anthracene 33-37 thiourea 6-10 phenol formaldehyde resin 3-5

Distinctive features provided an increase in the efficiency of smoke formation due to the higher burning rate of the composition and the increase in this case of gaseous products of combustion, which improves the dispersion of condensed products and reduces slag. In this case, the proposed composition is granulated and does not dust, therefore, it is technologically advanced to manufacture and safe to process.

The potassium chlorate content in the composition is optimized from the condition of maximum smoke generation.

When the content of anthracene in the range of 33-37 wt.% Provides incomplete combustion (without the formation of carbon dioxide and carbon monoxide) with a large emission of soot.

A content of less than 33 wt.% In anthracene is insufficient for the formation of black smoke, since anthracene is the main supplier of soot to the aerosol generated.

When the content in the composition of anthracene is more than 37 wt.%, Not all combustion products are dispersed and remain in the slag. This causes a decrease in the burning rate of the composition and leads to unstable combustion.

Thiourea in the composition works as a catalyst, lowering the decomposition temperature of potassium chlorate, thereby activating the combustion process of the composition.

A content of thiourea of less than 6 wt.% Is insufficient to provide a given burning rate.

When the thiourea content in the composition is more than 10 wt.%, It does not provide a noticeable increase in the efficiency of the smoke-forming composition, because many gaseous products of combustion are formed, which dilute the smoke, the contrast and brightness of which decrease, which worsens the purpose of the smoke curtain.

Phenol formaldehyde resin is introduced into the composition in the form of a 50% alcohol solution, which significantly improves the technological properties of the mixture, eliminates dusting during the manufacturing and processing of the composition, which is granulated and becomes friable. This allows you to dose the composition for pressing charges.

The introduction of phenol-formaldehyde resin in the composition in an amount of less than 3 wt.% Is not enough to obtain a sustainable improvement of technological properties in the industrial technology of manufacturing a smoke-forming composition.

When the content of phenol-formaldehyde resin in the smoke-forming composition is more than 5 wt.%, The burning rate decreases and, consequently, the generation of aerosol, that is, the purpose of the additive degenerates, which becomes ballast.

The technological additive of combustion activators - thiourea and phenol-formaldehyde resin, which are additional combustible, gives a large amount of gaseous products during the combustion of the composition, improves the dispersion of the aerosol and the removal of combustion products into the atmosphere, that is, increase its smoke-forming ability.

An increase in gaseous products also contributes to an increase in the dispersion of soot particles, which improves the stability of the smoke cloud and the opacity of the curtain.

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

The proposed composition is made by mixing the components in mixers type SND-100.

The optimal mass ratio of the components of the smoke-forming composition was calculated according to the mathematical model of the experimental design and verified by practical testing of the experimental compounds by evaluating the maximum service characteristics and destination indicators during their combustion.

Technical anthracene, TU 14-6-175, thiourea, GOST 6344 and 50% alcohol solution of phenol-formaldehyde resin SF-342-50, OCT B84-1467 are loaded in the mixer in the amount of half of the calculated mass, all this is mixed for 10 minutes.

Then, potassium chlorate (technical grade A Bertholeta salt), GOST 2713 and the second half of the alcohol solution of phenol-formaldehyde resin are loaded into the mixer. Stirring is carried out for 20-25 minutes.

The resulting mixture is unloaded on trays and dried for 20 minutes (kept at normal workshop temperature).

Next, the mixture is granulated by forcing through a mesh with cells of 2.0-2.5 mm in a granulator type PVG-1.

The formed granules of the smoke-forming composition are dried on the trays for at least two hours until the mass fraction of moisture and volatiles (not more than 0.5%) is reached. The finished granular composition is Packed and packaged in storage bags.

Comparative tests of the compositions according to the invention and the prototype were carried out in the standard design of the sea smoke bomb, in the housing of which there are six charges with a diameter of 120 mm, a height of 190 mm and a mass of 3.950 kg each.

For illustration, table 1 shows the characteristic composition of the experimental smoke charges that were tested during the development of the invention and optimization of compositions.

Table 1 Components The content of components, wt.% one 2 3 four 5 Prototype Potassium chlorate 56 55 52 53 fifty 52 Anthracene 32 35 33 37 38 48 Thiourea 5 6 10 7 eleven - Phenol formaldehyde resin 7 four 5 3 one -

Table 2 shows the indicators of the main technical characteristics of the appointment of characteristic compositions according to the invention in comparison with similar indicators of the composition of the prototype.

table 2 Characteristics Compositions one 2 3 four 5 Prototype Burning rate, mm / s 0.5 2.0 1.7 1,6 0.8 0.6-0.7 Smoke-forming ability,% 68 90 90 85 70 60-70 Slag content 32 10 10 fifteen fifteen 30-40

From table 2 it follows that the compositions according to the invention, with an optimal ratio of components, burn at a speed of 2-3 times faster than the known composition, reaching a maximum smoke-generating capacity of 90%, while the amount of slag is reduced to 10-15%.

Thus, the introduction of thiourea and phenol-formaldehyde resin (a total of 10-15 wt.%) Into the quantitatively balanced smoke-forming composition of the combustion activators significantly activated the combustion and aerosol formation processes in the form of a dense cloud of black smoke.

A comparative analysis of the proposed technical solution with identified analogues of the prior art, from which the invention does not explicitly follow for a pyrotechnic specialist, showed that it is not known, and taking into account the possibility of industrial production of a smoke-forming composition allows us to conclude that the patentability criteria are met.

The proposed composition is intended for the installation of masking curtains and false targets to protect surface ships from weapons with television guidance systems.

The use of charge from the new composition allows you to get an effective smoke cloud with a relatively compact dimensions of the checkers.

Claims (1)

Pyrotechnic smoke-forming composition containing potassium chlorate and anthracene, characterized in that it further includes combustion activators - thiourea and phenol-formaldehyde resin with the following components, wt.%:
potassium chlorate 52-55 anthracene 33-37 thiourea 6-10 phenol formaldehyde resin 3-5