RU2288207C1 - Composition for solid fuel - Google Patents

Abstract

FIELD: solid rocket fuels.

SUBSTANCE: composition comprises polyolefin (polyethylene, polypropylene, polybutylene, and polybutadiene) as a fuel, ultra finely divided powder of metal (powder of boron, aluminum, magnesium or their mixture) carboran or its derivatives as phenylcarboran, and isopropylcarboran.

EFFECT: enhanced energy content and burning rate.

1 tbl, 4 ex

Description

The present invention relates to the field of fuels for ramjet engines (ramjet), and in particular to solid organic fuels for use in ramjet engine (ramjet) external and internal afterburning in pre-, supersonic or hypersonic air flow.

Compared to gaseous, liquid, and gel-like fuels used in ramjets, solid fuels are characterized by comparative ease of use and shorter preparation time for launch. A solid fuel ram ram is simpler in design. There are no tanks, pumps for pumping fuel components, etc. (“Missile fuels” edited by Ya.M. Paushkin and A.Z. Chulkov. - M. Mir, 1975, 188 pp .; “Energy condensed systems” edited by B.P. Zhukov, M., “Janus -K ", 2000, 596 pp.).

The solid fuels used in ramjet are known, based on polyolefins, in particular, on the basis of combustible binders - a copolymer of isobutylene and isoprene (US Pat. No. 3,012,866, CL 149-46, December 1961) and polyisoprene (US Pat. No. 3,122,461, C. 149-22, February 1964), in which perchlorates, chlorates and ammonium permanganates are used as an oxidizing agent.

For ramjet rams with an afterburning chamber for under-oxidized solid fuel combustion products in a supplied air stream, solid fuels are proposed that contain an oxidizing agent in an amount sufficient to maintain the combustion of the fuel, but not sufficient to completely oxidize it.

Solid fuel is described (US Pat. No. 6,736,912 B1, IPC ⁷ C 06 B 45/10, nat. CL 149 / 19.9, May 2004) containing at least 50% binder based on polybutadiene with terminal hydroxyl groups and crosslinked polystyrene , less than 10% of a mixture of fluorinated carbon (CF _x ) _n and one of the elements B, Al, Mg, or a mixture thereof, the rest is ammonium perchlorate and up to 3% of a combustion catalyst.

The reaction between aluminum, as well as boron and magnesium, and (CF _x ) _n is exothermic, oxidizing the hydrocarbon fuel with ammonium perchlorate. However, the amount of oxidizing agent only supports combustion, but it is not enough for complete oxidation. The afterburning of the combustion products occurs in the combustion chamber in the supplied high-speed flow of air.

In US patent (US Pat. No. 3986909, IPC C 06 D 5/06 nat. CL 149 / 19.9, October 1976), adopted as a prototype, describes solid fuel for ramjet with an afterburner chamber for the combustion of products of incomplete combustion of fuel containing 10 -50% binder based on polybutadiene, polybutadiene with terminal hydroxyl or carboxyl groups, polyethylene, polyesters, etc., not less than 25% boron, aluminum or magnesium, the rest is an oxidizing agent, in an amount sufficient to support combustion, but not sufficient for full combustion of combustible components, which after gasification burn We were in the combustion chamber in the incoming air stream.

The disadvantage of solid fuels for ramjet engines containing both fuel and oxidizer in their composition is their low energy characteristics compared to ramjet engines on liquid fuel and atmospheric air, as well as increased sensitivity to mechanical and temperature influences. Another disadvantage is (also due to close contact between the oxidizing agent and fuel) storage instability.

The objective of the invention is to improve energy performance and increase the burning rate of fuel.

To solve this problem, a solid organic fuel composition is proposed, including a polyolefin, an ultrafine metal powder, which according to the invention additionally contains carboran or its derivative with the following content of components, wt.%:

Polyolefin 36-95 Ultrafine metal powder 0.5-50 Carboran or its derivative 4-15

As the polyolefin take: polyethylene, polypropylene, polybutylene, polybutadiene. As a derivative of carborane - phenylcarborane, isopropylcarborane. Of ultrafine metal powders, powders of boron, aluminum, magnesium or mixtures thereof are proposed.

Methods for producing solid organic fuel compositions are given in examples 1-4, the composition of the compositions and the test results are shown in the table.

Example 1

95% powdered high pressure polyethylene (PE), 4.5% o-carborane powder and 0.5% boron powder were thoroughly mixed in a drunken drum type mixer. The mixture was placed in a mold, heated at a temperature of 180 ° C for 20 min, the melt was evacuated, and it was pressed in a mold in a heated state under a pressure of 10 kg / cm ² . The mold spontaneously cooled for 30 minutes. After cooling, the mold was disassembled and a solid fuel checker was obtained.

Example 2

84.5% of powdered PE, 15% of powdered o-carborane and 0.5% of aluminum powder were mixed in a drunk barrel mixer. The mixture was loaded into a working extruder with a nozzle allowing to obtain a tube-shaped charge of fuel with the required internal and external diameters, and was extruded at a temperature of 110-130 ° С. A tube was obtained, which was then cut into sections of a given length.

Example 3

At the same time, granular polypropylene (PP) and powdered phenylcarboran (FC) and boron were loaded into the extruder using dosing devices in a weight ratio of PP: FC: boron = 80: 15: 5. Extrusion was carried out at a temperature of 150-190 ° C. With the pressure screw, the fuel mass was pumped into the mold. After cooling and disassembling the mold, a solid fuel charge with specified geometric parameters was obtained.

Example 4

In a drunk barrel type mixer, piston-like PE, boron and phenylcarborane powders were mixed in a mass ratio of PE: B: FC = 50: 46: 4. The mixture was placed in a mold and heated at a temperature of 180-190 ° C for 20 minutes under reduced pressure. Then the mixture was pressed. After cooling, the mold was disassembled and a block of solid fuel filled with boron with a given internal and external diameter was obtained. The density of 1.3 g / cm ³ .

The proposed solid fuel composition based on PO has the advantages of liquid fuels and solid fuels and is free from their disadvantages. In particular, in terms of energy performance, it is not inferior to liquid hydrocarbons and at the same time it allows to reduce operating costs, increase reliability, significantly reduce start-up time, and simplify engine design.

The blocks of the proposed solid fuel do not contain an oxidizing agent, so they are more stable during storage. They are not sensitive to detonation.

The composition provides a high calorific value and increase the burning rate of fuel charges. It is characterized by the simplicity of the manufacture of charges and the reliability of operation of a motor, traction or control direct-flow actuator.

Table №№ p.p. Name of components The quantitative content of the components in the examples (wt.%) Prototype one 2 3 four 5 6 7 8 9 10 one. Polyethylene - 95.0 84.5 - 50,0 36.0 - 50,0 50,0 - 50,0 2. Polypropylene - - - 80.0 - - - - - - - 3. Polybutylene - - - - - - 90.0 - - - - four. Polybutadiene 35.0 - - - - - - - - 50,0 - 5. o Carboran - 4,5 15.0 - - 14.0 - 10.0 10.0 15.0 10.0 6. o-phenylcarboran - - - 15.0 4.0 - - - - - ~ 7. Isopropyl methacarborane - - - - - - 9.5 - - - - 8. Boron 45.0 0.5 - 5,0 46.0 - - 40,0 20,0 35.0 - 9. Aluminum - - 0.5 - - 50,0 0.5 - 20,0 - - 10. Alloy of aluminum and magnesium, PAM-4 - - - - - - - - - - 40,0 eleven. Oxidant - ammonium perchlorate 20,0 The increase in combustion rate,% - 35 45 40 35 thirty 35 40 45 thirty thirty Calorific value Hu, kJ / kg 39100 45100 46840 46460 51160 39890 41740 55880 40540 51890 39510

Claims (1)

A solid fuel composition for ramjet external and internal afterburning in a sub-, supersonic, or hypersonic air stream containing a polyolefin as a fuel and an ultrafine metal powder, characterized in that it further comprises carboran or its phenylcarboran derivative, isopropylcarborane, in as polyolefin - polyethylene, polypropylene, polybutylene, polybutadiene, and as an ultrafine metal powder - boron, aluminum, magnesium powder or a mixture thereof in the following components, wt.%: Polyolefin 36-95 Ultrafine metal powder 0.5-50 Carboran or its derivative 4-15