RU2170721C1 - Method for production of mixed solid fuel charges - Google Patents

Abstract

FIELD: rocket fuels. SUBSTANCE: process consists of following stages: preparing oxidant, preparing mixture of binding agent with metal combustible and additives, preparing mixture of hardener components, preparing engine cases, preparing fuel, molding, polymerization, pressing-out, and defectoscopy. To increase combustion rate of fuel and constancy of its value, combustion catalyst (iron oxide or its mixture with other metal oxides) preliminarily dispersed in binding agent is added to fuel in certain stages in the form of suspension. Fuel can be used in rocket engines and in salvo-fire systems. EFFECT: improved combustion conditions. 1 tbl

Description

 The invention relates to the field of production of rocket technology, namely to the manufacture of mixed solid fuel (CTT) charges, which can be equipped with rocket engines, for example, multiple launch rocket systems.

 The CTT charge is a block (usually with an internal channel) molded or poured into the engine block of the required shape, CTT, which is (1, 2) a heterogeneous cured mixture: an oxidizing agent (60-80%), a polymer binder (13-25%), metal fuel (5-20%) and various additives (up to 5%): catalytic, technological, etc.

A known method for the manufacture of charges CTT (3, p. 96-98), (4), including phase:
- grinding of oxidizing agent and metallic fuel;
- preparation of a fuel binder in the form of a liquid-viscous system;
- mixing of all components in the mixer with subsequent deaeration (evacuation) of the fuel mass;
- the preparation of the buildings with the application of a protective-fixing (armor) composition, the installation of a channel forming tool with applied anti-adhesive coating;
- molding (casting) of the charge;
- polymerization;
- extrusion (extraction of the forming channel snap);
- flaw detection.

 The disadvantage of this method is the inability to achieve a uniform distribution of metallic fuel in the fuel volume, which can lead to heterogeneity of ballistic, physical, mechanical and other characteristics of various parts of the charge.

Also known is a method (3, p. 99-100), (5) a prototype in which the aforementioned drawback is eliminated by introducing the operation of preliminary mixing of metallic fuel (usually aluminum) with a polymer binder. This method includes the following phases:
- preparation of an oxidizing agent, including the operations of drying, grinding, fractionation, mixing in a certain ratio of various fractions;
- preparation of a mixture of binder components with metal fuel - aluminum and additives;
- preparation of a mixture of hardener components;
- preparation of engine housings, including the application of a protective and fixing composition to its internal walls and the installation of a snap-forming channel;
- preparation of the fuel mass, including dosing, mixing in the mixer prepared components, evacuation;
- charge shaping (pouring fuel mass into the engine housing);
- polymerization;
- pressing out (extraction of technological equipment for forming channels and charge);
- flaw detection.

 The disadvantage of this manufacturing method is the insufficiently high level of the rate of combustion of the fuel charge.

 The objective of the present invention is to develop a method of manufacturing a charge CTT, providing a higher level of combustion rate of fuel charge, as well as the stability of its value.

 The problem is solved due to the fact that in the known method of manufacturing CTT charges containing an oxidizing agent, a polymeric binder, metal fuel and additives, including the preparation of the oxidizing agent, preparing a binder mixture with metal fuel - aluminum and other additives, preparing a mixture of hardener components, preparing bodies engines, fuel mass preparation, molding, polymerization, extrusion and flaw detection, during the preparation of a binder mixture with aluminum and other additives, and whether during the preparation phase of the mixture of hardener components, or immediately before the preparation of the fuel mass, a combustion catalyst is introduced into the fuel - iron oxide or its mixture with other metal oxides in an amount of 0.005 - 5.0 wt.%, which is pre-dispersed in the medium of the liquid components of the binder to achieve average particles and agglomerates of 0.5 - 5.0 μm, and the input of the catalyst is carried out in the form of the resulting suspension.

 So, a significant difference of the proposed method for producing CTT charges is that at the stages of preparing the fuel composition, an additional 0.05 - 5.0 wt.% Combustion catalyst is added to the composition — iron oxide or its mixture with other metal oxides. The catalyst must be pre-dispersed until the average particle size (or agglomerates thereof) is reached, since with such dispersion of the material stable agglomerates can form, behaving, for example, when measuring dispersion as whole particles), the limits are 0.5-5.0 μm, since their average size of more than 5 microns does not achieve a sufficient catalytic effect, and with an average particle size and agglomerates of less than 0.5 microns, the resulting catalytic effect does not justify the costs involved. When dry dispersed, such finely dispersed materials when working with them (unloading, dosing, etc.) are very dusty, and at the same time, the finest dispersed part with the greatest catalytic effect flies away. In addition, during storage, they can adsorb other substances, for example, water, significantly changing their characteristics, including dispersion. Therefore, to ensure the stability of a high level of the rate of combustion of the fuel charge, the proposed dispersion of the catalyst should be performed in a liquid medium, which should be used as the liquid components of the binder of this fuel (rubber, resins, their plasticizers). In this case, it is possible to introduce the catalyst into the fuel composition in the form of the same suspension obtained during the dispersion process without removing the dispersed medium, since it is also a fuel component. The dispersion of the catalyst can be carried out on a disintegrator, ball mill or other dispersing devices that allow dispersion in a liquid medium.

Thus, the proposed method of manufacturing a charge of CTT includes the following phases:
- preparation of the oxidizing agent, including the operation of drying, grinding, fractionation, mixing in a certain ratio of different fractions;
- preparation of a binder mixture with a metal fuel - aluminum and additives;
- preparation of a mixture of hardener components;
- preparation of engine housings, including the application of a protective and fixing composition to its internal walls and the installation of technological equipment for the channel forming
- preparation of the fuel mass, including dosing, mixing all the components in the mixer, followed by evacuation;
- molding (pouring into the engine housing);
- polymerization;
- pressing out (extraction of technological equipment for forming channels and charge);
- flaw detection,
and also includes the operation of introducing into the fuel composition 0.05 - 5.0 wt.% the combustion catalyst - iron oxide or its mixture with other metal oxides in a ratio of 9: 1 - 1: 9, which is pre-dispersed in the medium of the liquid components of the binder to medium the particle size and agglomerates (RMS) of 0.5-5 μm and then introduced into the fuel composition in the form of a suspension obtained by dispersion, and the introduction of the catalyst is carried out in phases or preparation of a mixture of a binder with aluminum and additives, or preparation of a mixture of hardener components (at unlike some of the liquid components of the binder in this mixture), or immediately before mixing all the components in the mixer.

 According to the proposed method and the prototype method, samples of CTT charges were manufactured and tested. The results are shown in the table. It follows from them that the simple introduction of a combustion catalyst at the indicated phases of the CTT charge manufacturing process allows increasing the level of the charge fuel burning rate from 14 to 21 mm / s, i.e. 46-48% K. However, the instability of the burning rate increases by 18-24%, which was estimated by the standard deviation from the average burning rate (according to the results of the manufacture and testing of ten fuel samples of each type). With the introduction of a combustion catalyst in the form of a suspension, the binder previously dispersed in a liquid medium to the required RMS, the burning rate increases by 60-70%. Moreover, the stability of the burning rate is not worse than on fuel without a catalyst.

Sources
1. Horst A.G. Gunpowder and explosives. - M.: Mechanical Engineering, 1972, pp. 178-179.

 2. Shidlovsky A. A. Fundamentals of pyrotechnics. - M.: Mechanical Engineering, 1973, p. 264-266.

 3. Grigoriev A.I. Solid rocket fuels. - M.: Chemistry, 1969, p. 116.

 4. Fakhrutdinov I.Kh., Kotelnikov A.V. Design and engineering of solid propellant rocket engines. - M.: Mechanical Engineering, 1987, p. 43-45.

 5. Smirnov L.A., Klabukhov G.V. The creation of mixed solid fuels. Part 1. - M .: MGAHM, 1997, p. 104-106.

Claims (1)

 A method of manufacturing charges of mixed solid fuel containing an oxidizing agent, a polymeric binder, metal fuel and additives, including the preparation phases of the oxidizing agent, preparing a binder mixture with metal fuel - aluminum and other additives, preparing a mixture of hardener components, preparing engine bodies, preparing fuel mass, molding, polymerization, extrusion and flaw detection, characterized in that in the phase of preparation of a mixture of a binder with aluminum and other additives, or in the phase a mixture of hardener components, or immediately before the preparation of the fuel mass, a combustion catalyst is introduced into the fuel - iron oxide or its mixture with other metal oxides in an amount of 0.005 - 5.0 wt.%, which is previously dispersed in the medium of the liquid components of the binder until the average particle size is reached and agglomerates of 0.5 to 5.0 μm, and the introduction of the catalyst is carried out in the form of the resulting suspension.

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