EP2580175A1 - Method for producing and using an explosive substance mixture containing fuel - Google Patents

Abstract

The invention relates to a method for producing a mechanical explosive substance mixture which is to be processed using pressing techniques and which consists of a granular fuel or a granular pyrotechnic mixture, a desensitised explosive agent and graphite. The method is safe, efficient, flexible and cost-effective and thus makes it possible to provide fuel-containing explosive substance mixtures in wide composition ranges for use in infantry ammunition such as hand grenades or ammunition for man-portable mortars. The granular fuel or granular pyrotechnic mixture is produced separately in a fluidised bed process or a multi-stage kneading, granulating and fabricating process, is fractionated to a grain size of 0.2 mm to 0.8 mm and, adding graphite, is then mixed mechanically with available grades of desensitised explosive agents and processed using pressing techniques.

Description

 DESCRIPTION

for the production and use of a fuel-containing explosive mixture

The present invention is concerned with the production of a mechanical explosive mixture to be processed by prescription, which consists of a fuel granulate or a granulate of a pyrotechnic mixture, a desensitic explosive and graphite. In addition, the use of fuel-containing (inorganic fuels) explosives mixtures in highly explosive bivalve explosives, hereinafter also referred to as Blast active charges, in infantry applications primarily to combat targets in the enclosed space considered. These blast active charges comprise a centrally located cylindrical HE core core.

The asymmetric conflicts that have been intensified in recent decades and their increasing relocation to urban areas has led to new demands of the emergency services for appropriate means of action and ammunition. In order to effectively combat targets in bunkers, field fortifications, cave systems or appropriately developed premises in urban environments, effective systems and ammunition are required, while at the same time avoiding collateral damage wherever possible to curb such scenarios, especially in urban environments ,

From the above, it follows that conventional splinter munitions based on high-explosive mixtures are increasingly being replaced by systems acting as selectively as possible, including new blast ammunitions, and should continue to be replaced. This applies in particular to infantry agents.

The blast performance of explosive charges can usually be detected in the form of the pressure pulse. An increase of the pressure pulse under given conditions (free field or enclosed space) can be achieved by increasing the peak pressure to be achieved, by a longer-term comparative but lower (lethal) peak pressure, or a combination of both.

In addition to the variation of the explosives or Explosengstoffabmischungen to be used, a possible reduction of Inertstoffanteile (binder) or substitution of inert or low-energy binder components by high-energy binder components, an increase in performance can also be achieved by the addition of inorganic fuel components.

As a starting point for numerous such developments in the field of blast active charges blends of organic explosives or explosive mixtures with aluminum powder, as they have long been z. B. in the field of explosives for bombs, torpedoes u. Ä. to be used; literature known mixtures are z. Torpex, DBX, HBX.

The mixtures of conventional HE explosives or explosive mixtures with inorganic fuels are to be designated in terms of their oxygen balance as non-ideal explosives or explosive mixtures. This generic term also includes blends based on real or particulate gels, consisting of a liquid organic phase (LOP) and a mostly inorganic fuel.

Depending on the oxygen balance of the HE explosive or explosive mixture, the nature and quality of the inorganic fuel and the oxygen balance of the total mixture of HE explosive or explosive mixture and inorganic fuel, mixtures of HE explosives or explosive mixtures with inorganic fuels to observe different blast effects.

In the wake of the demands for insensitive and / or performance-enhanced explosives and ammunition, numerous castable, melt-castable, extrudable or compressible fuel-containing explosive mixtures have been developed in recent decades. Initially, the focus was mostly on blends of explosives with a tendency to lower fuel contents, since blends of such explosives generally also have a high splinter acceleration capability in appropriately designed ammunition. An example of this is the blending of HE explosives or explosive mixtures with aluminum. These are certainly among the most intensively theoretically as well as practically examined systems. One off if necessary Explosion temperature of the reaction products derivable thermal, pressure-enhancing effect for the system RDX-AI can be found for example in US 7,393,423 B2. Here, for the composition of a system comprising 19.5% by weight of aluminum and 80.5% by weight of RDX, a temperature maximum about 600 ° C. above the swath temperature of pure RDX is stated.

Literature known pourable mixtures are u. a. PBXN-109 (hexogen / aluminum) and PBXW-114 (octogen / aluminum), compressible compositions known in the literature, which are prepared by mechanically mixing desensitized explosives with aluminum powder: a) 70/30 Composition A3 (91/9 hexogen / wax, microcrystalline ) / Aluminum powder; b) Hexal: 80/20 hexogen (with 5 wt% wax) / aluminum powder.

No. 5,472,531 A discloses an extrudable and compressible explosive formulation based on octogen (40% by weight to 80% by weight) and aluminum powder (1% by weight to 40% by weight). In the explosive formulation, CAB is used as a binder and a mixture of BDNPA and BDNPF as an energetic plasticizer.

WO 2005/108329 A1 proposes a compressible explosive formulation based on hexogen or octogen (45% by weight to 95% by weight) and passivated aluminum powder (5% by weight to 55% by weight). A possible binder is an ethyl / butyl acrylate copolymer in conjunction with plasticizers such as dioctyl adipate, dioctyl sebacate and isodecyl perlagonate.

A variety of developments in the field of blast active charges aims at increasing the pressure pulse by high peak pressures. In the case of inorganic fuels, various investigations and developments are therefore being carried out on the use of so-called nanoscale powder grades with particle diameters of less than 1 μm to accelerate the reactions. The problem of the reaction-inhibiting oxide layer of such powders (boron and many light metals) and the prevention of the passivation of reactive metal surfaces in the respective blends by appropriately upstream coating processes are well known.

By circumventing the above-mentioned problems, the explosive charge proposed on the basis of red phosphorus (RP) as inorganic fuel by DE 10 2006 030 678 B4 represents a blast active charge with very high pressure-volume work. With regard to a depth effect (cave systems and the like) that can also be achieved at least partially around obstacles, the fuel-laden Blast active charges have increasingly become the focus of interest among the emergency services in recent years.

Another potential advantage of these active charges is that their blast effect depends more strongly on the inclusion conditions than is the case with less heavily imbalanced active masses, so that, for example, when using such active charges in MOUT scenarios, possibly with a reduced risk of collateral damage ( Lethal blast effect drops rapidly when leaving the enclosed space).

In addition to the variation of the compositions of different levels of explosive blended fuel blends a blast effect to be achieved can also be achieved or enhanced by a multi-shell structure. In the field of unguided or guided discharge ammunitions, etc., such systems are already common. These consist of a usually centrally arranged burster and initiation charge around which a fuel-containing secondary charge is arranged, which in turn may be surrounded by a shell of pressed fuel powder (with binder surcharges) (double-shell explosive charge).

The central booster charge can be conventional HE explosives or explosive mixtures or mixtures of these with inorganic fuels. The secondary charge may consist of a heavily under-exploited explosives active mass or of a pure fuel or fuel mixture, possibly with additional processing aids.

Some examples are z. As the US 6,969,434 B1 refer. Here, the outer shells of granulated fuel-Oxidationsmittelabmischungen be pressed, in which then z. B. HE charges in the form of blends of explosives (RDX, HMX, CL-20), binder (HTPB, LMA ...), the above-mentioned fuel-oxidant granules and optionally additional oxidant (ammonium perchlorate) are poured.

In US 6,955,732 B1 is the fuels such. B. different aluminum qualities, possibly in admixture with magnesium, aluminum magnesium alloy, titanium in admixture with boron, etc. basically ammonium perchlorate mixed as an oxidizing agent. As a binder of the fuel-oxidizer blends, Viton® or nitrocellulose is used in amounts of four to six percent by weight. In addition, the fuel-oxidizer blends may optionally contain an iron oxide catalyst in amounts of about one weight percent contain. According to US Pat. No. 6,955,732 B1, in analogy to the charge structure in US Pat. No. 6,969,434 B! Also multi-shelled granules of an inner HE core (HMX + binder) with aufzagged metal composites (various inorganic fuels + ammonium perchlorate + binder + possibly plasticizer + possibly catalyst) proposed.

US Pat. No. 5,996,501 describes a large-caliber bivalve charge with an inverse structure (charge core made of metal powder-containing non-ideal explosive mixture (diameter: 10 cm to approx. 30.5 cm) / outer shell made of a "classic" explosive mixture) as a pressure-boosting charge with simultaneously increased splinter acceleration capability The non-ideal explosive mixture of the charge core is composed of an explosive (TNT or RDX), aluminum powder, ammonium perchlorate and wax as a binder.

The above-described examples of US Pat. No. 6,955,732 and US Pat. No. 6,969,434 B1 are primarily suitable for use in cost-intensive, large-caliber applications. Against the background of costs alone, the widespread use of relatively expensive explosives such as octogen or even CL-20, or the nanoscale fuels and composites that are often not yet available in sufficient quantities, appears rather unlikely in the near future in smaller blast blasts.

US 7,727,347 B1 discloses a hand grenade with a thermobaric charge.

The invention has for its object to provide a blast-effective charge or a manufacturing process for the blast effect with the aim of a cost-effective and thus broader application in infantry applications, such as hand grenades, man portable mortar etc.

The object is achieved by the features of claim 1. Advantageous embodiments are the dependent claims.

The invention is based on the idea of producing small blast active charges, in which case common explosives or blended explosives and common fuel qualities are used as raw materials in the first place.

In the field of infantry agents, only EP 2 151 422 A2 has hitherto proposed the use of fuel-containing (RP) explosive formulations in the form of a hand grenade. In continuation of the invention from DE 10 2006 030 678 B4 be Detergents based on blends of the explosives CL-20, HMX, RDX or TEX with red phosphorus (10 wt .-% to 80 wt .-%) for optional use as explosive charge (detonative reaction) or pyrotechnic fog (deflagrating reaction) mentioned , The mentioned high blast effect of these RP-containing explosive blends is the formation of phosphoric acid mist certainly given in a detonative implementation disadvantageous, since this obstructs the forces especially in MOUT scenarios at short to very short deployment distances of a few meters more or less.

The present invention is based in turn on the basis of mixtures of inorganic fuels - plus possibly inorganic oxidants - in combination with organic explosives (explosives including nitrocellulose) compressible, two-shell explosive charges up to a mass of 1, 0 kg and a total charge diameter of 8 cm To provide, which have primarily in the enclosed space a pressure impulse enhancing performance.

The blast active charges can consist of a uniform granulate (mixtures of inorganic fuels - plus possibly inorganic oxidants -, organic explosives, a binder or binder system and possibly other additives) or a mixture of fuel granules - with possibly mixed inorganic oxidizing agents - an organic explosive mixture or conventional Sprengstoffgranu- lates optionally be pressed with the addition of graphite. In this case, the fuel granules or granules of a pyrotechnic mixture is first prepared separately in a fluidized bed process or a multi-stage kneading, granulation and confectioning process and fractionated from a predetermined particle size> 0.8 mm. The thus prepared fuel granules or granules of a pyrotechnic mixture are mechanically miscible in wide compositional ranges simply with the addition of graphite with available qualities of desensitized explosives.

The fuel granulate is produced in a fluidized bed process in such a way that 5% by weight to 90% by weight of the pulverulent inorganic fuel or fuel mixture are introduced into the fluidized bed and the remaining portion of the fuel or fuel mixture (10% by weight to 95%) Wt .-%) in a binder solution consisting of an organic binder and a solvent or solvent mixture suspended in the fluidized bed is injected. Alternatively, the fuel granules or granules of the pyrotechnic mixture in a multi-stage kneading, granulation and confectioning be prepared such that the powdered inorganic fuel or the powdery inorganic fuel mixture or the powdered pyrotechnic mixture in a kneader and after addition of the binder solution consisting of an organic binder and a solvent or solvent mixture, mixed homogeneously, then granulated and solvent-dried in a drum or a coating pan and then dried distributed on trays drying.

In the case of using Viton as a binder for the fuel granules or the granules of the pyrotechnic mixture, a ketone is used as a solvent or a mixture of a Ke tons and an acetic acid ester as a solvent mixture for the preparation thereof. In the case of using polyvinyl alcohol as a binder for the fuel granules or granules of the pyrotechnic mixture for producing the same, an alcohol is used as a solvent or a mixture of an alcohol and water as a solvent mixture.

The inorganic fuel contained in the fuel granules or granules of a pyrotechnic mixture comprises various qualities of the elements aluminum, boron, magnesium, titanium or zirconium and alloys and mixtures thereof. The inorganic oxidizing agent or oxidizing agent mixture contained in the granules of the pyrotechnic mixture comprises substances from the groups nitrates, oxides or peroxides.

The desensitized explosive is a granulate of one in amounts of 2 wt .-% to 8 wt .-% with wax or wax and graphite or Viton® desensitized explosives or a mixture of explosives of cyclotrimethylenetrinitramine (RDX), cycotetramethylenetetranitramine (HMX), pentaerythritol tetranitrate (PETN) or trinitrotoluene (TNT).

The method is safe, efficient and inexpensive in this form, since when using granulated fuels or pyrotechnic granules in the specified particle size range of 0.2 mm to 0.8 mm can be burned, fuel-rich Blastwirkladungen simply by tumbling the components and then simple compression without pressure equalization discs (US 7,727,347 B1) to use. It enables the provision of fuel-efficient explosive mixtures which are easy to process for use in infantry munitions such as hand grenades or man-portable mortars, etc. The blast active charge is based on compressed blends of granulated inorganic fuels or granulated pyrotechnic mixtures of inorganic fuels and perchlorate-free inorganic oxidants in conjunction with commercial organic explosive granules, with a centrally located, cylindrical high-explosive burster and / or initiation charge. The bulk density and grain shape of the fuel granules or granulated, perchlorate-free pyrotechnic mixtures can be procedurally adapted to the commercial explosive granules to be used and thus enable good miscibility and simple press-technical further processing in other mixing ranges.

Reference to an embodiment with drawing, the idea will be explained in more detail. As an application example, a hand grenade is considered in more detail here. However, this is not restrictive, since applications are also possible with ammunition with blast effect.

The compressed blast active charges proposed here have a bivalve structure consisting of a centrally positioned (cylindrical) compressed HE core core 1 and the compressed, fuel-containing explosive mixture 2 arranged around it (compare the single figure). 3 is a two-piece preferably screw-in cargo container, preferably made of plastic, wherein the screw cap has a recess for receiving the spatially separated from the double-shell explosive charge 1, 2 delay detonator unit. A rocker arm igniter with detonator cap and the detonator unit bears the reference numeral 4.

The centrally arranged HE core 1 may have a diameter of 8 mm to 50 mm and be composed of one or more compacts. The explosive mixture 2 arranged around it consists of one or more ring tablet press linings having a maximum diameter of 80 mm.

The HE core 1 can be made of a uniform granules (blending of organic explosives, a binder or binder system, possibly inorganic fuels and possibly other additives), commercially available desensitized explosives (RDX or HMX), if necessary with the addition of graphite or fuel granules (Up to 20 wt .-%) and graphite, etc. are pressed.

The fuel-containing explosive mixture 2 arranged around the HE core core 1 can be made from a uniform, fuel-containing explosive granulate (eg. in accordance with the statements in WO 2005/108329 A1 or US Pat. No. 5,472,531 A1 or else from a mechanically produced mixture of a desensitized explosive (RDX or HMX) or stabilized nitrocellulose and a fuel granulate, optionally with the addition of graphite.

In connection with the blending of desensitized explosives with aluminum powder (eg Hexal or Composition A3 / Aluminum), the literature mentions the problem of the potential inhomogeneity of these mechanical blends and the associated performance variations. In the case of the inventively proposed use of mechanically produced Explosivstoffabmischungen 2, the inorganic fuels - plus possibly inorganic oxidants - in the form of granules, which preferably have a particle size of 0.2 mm to 0.8 mm used. As a result, mechanical production of the explosive mixtures according to the invention is ensured in satisfactory homogeneity.

With a view to changing application scenarios (multirollability), the performance or proposed here blast active charges in the open field by constructive and / or chemical variation of the same as at least comparable or better with the same dimensioned, classic explosive charges, as z. B. used in hand grenades can be adjusted. This requirement meet gelartige effective charges without explosives surcharges z. B. on the basis of isopropyl nitrate usually not.

In view of ongoing discussions regarding possible health-damaging environmental damage caused by perchlorate-contaminated groundwaters, the mixtures of inorganic fuels proposed here in connection with organic explosives are basically free from perchlorate. This is especially true for ammonium perchlorate, which in addition to a high water solubility also has the disadvantage, for. As in pyrotechnic sentences to increase the friction and impact sensitivity of the same and thus runs counter to any requirements regarding the insensitivity of HE combat munitions. The last point is important in that the reasons for the often required splinter reduction / freedom from fragmentation in the ammunition to be made available must be waived if applicable to IM-functional, thick-walled enclosures.

With a view to achieving a depth effect in the enclosed space, the explosive mixtures 2 proposed here are rich in fuel and have fuel or fuel granulate fractions, including any additions of inorganic oxidants. Onsmitteln - from 31 wt .-% to 72 wt .-% (weight percent), but preferably from 56 wt .-% to 65 wt .-% on.

The proposed mixtures of inorganic fuels and organic explosives contain 2 to 15 wt .-% of one or more binders or a binder system and optionally further additives with a total of up to 7 wt .-%.

Wax and / or the mixture known by the name of Viton are preferably used as binders, but the use of other binder or binder systems is expressly not excluded hereby.

Claims

A process for preparing an explosive mixture comprising

 A fuel granulate consisting of from 92% to 98% by weight of an inorganic fuel or a mixture or alloy of inorganic fuels and an organic binder in amounts of from 2% to 8% by weight, or

 A granulate of a pyrotechnic mixture consisting of an inorganic fuel or a mixture or an alloy of inorganic fuels in quantities of 15% by weight to 86% by weight, an inorganic oxidizing agent or

 An oxidizing agent mixture in amounts of from 12% by weight to 83% by weight and an organic binder in amounts of from 2% by weight to 8% by weight,

 • which were produced in a fluidized bed process and / or in a multi-stage kneading, granulation and confectioning process,

 A mechanical mixing of the granules of a pyrotechnic mixture fractionated to the grain sizes of 0.2 mm to 0.8 mm of a pyrotechnic mixture in amounts of 18 wt .-% to 72 wt .-% with a desensitierten explosive or explosive mixture in amounts of 28 wt .-% to 82 wt .-% and graphite in amounts of 0 wt .-% to 2 wt .-% and

 • a prespecification of the mechanical explosive mixture into pellets or cargoes.

2. The method according to claim 1, characterized in that the fuel granules are prepared in a fluidized bed process such that 5 wt .-% to 90 wt .-% of the powdered inorganic fuel or fuel mixture are placed in the fluidized bed and the remaining portion of the fuel or Fuel mixtures (10 wt .-% to 95 wt .-%) in a binder solution consisting of an organic binder and a solvent or solvent mixture suspended in the fluidized bed is injected.

3. The method according to claim 1, characterized in that the fuel granules or granules of the pyrotechnic mixture in a multi-stage kneading, granulation and confectioning process is prepared such that the powdered inorganic Fuel or the powdered inorganic fuel mixture or the pulverför- pyrotechnic mixture presented in a kneader and homogeneously mixed after addition of the binder solution consisting of an organic binder and a solvent or solvent mixture, then granulated and solvent-wet in a drum or a coating pan and then is dried on hordes distributed.

4. The method according to any one of claims 1 to 3, characterized in that in the case of using Viton as a binder for the fuel granules or the granules of the pyrotechnic mixture, a ketone as a solvent or a mixture of a ketone and an acetic acid ester used as a solvent mixture for producing the same and that in the case of using polyvinyl alcohol as a binder for the fuel granules or granules of the pyrotechnic mixture for producing the same, an alcohol is used as a solvent or a mixture of an alcohol and water as a solvent mixture.

5. The method according to any one of claims 1 to 4, characterized in that the fuel contained in the fuel granules or granules of a pyrotechnic mixture comprises different qualities of the elements aluminum, boron, magnesium, titanium or zirconium and alloys and mixtures thereof.

6. The method according to any one of claims 1, 3 and 4, characterized in that the inorganic oxidizing agent or oxidizing agent mixture contained in the granules of the pyrotechnic mixture comprises substances from the groups nitrates, oxides or peroxides.

7. The method according to any one of claims 1 to 6, characterized in that the desensitivierte explosive granules of one in amounts of 2 wt .-% to 8 wt .-% with wax or wax and graphite or Viton® desensitized explosive or a blend explosives of cyclotrimethylenetrinitramine (RDX), cycotetramethylenetetranitramine (HMX), pentaerythritol tetranitrate (PETN) or trinitrotoluene (TNT).

8. The method according to any one of claims 1 to 7, characterized in that press-technical processing of the mechanical explosive mixture to pellets or charges preferably takes place up to a total diameter of 8 cm.

9. Ammunition in the form of hand grenades, mortar or launcher grenades or submunitions of hand grenades, mortar or launcher grenades, with a compressed explosive mixture according to any one of claims 1 to 8.