RU2134861C1 - Method and device for ammunition salvaging - Google Patents

Abstract

FIELD: salvaging of armaments, applicable for extraction of explosives from ammunition bodies, as well as from solid-propellant jet engines, cumulative perforators, jet casing cutters, etc. SUBSTANCE: at salvaging of ammunition fitted with a solid propellant charge by the effect of shock wave formed at an explosion of fuel gas mixture surrounding the ammunition and being under the preset initial pressure the crushed mass is extracted. The initial pressure of fuel gas mixture is determined according to the dependence of the parameters of its detonation on the parameters of the initial state by the known procedure. Besides, the effect is accomplished repeatedly. The device for realization of this method has an explosion chamber hermetically joined to a bedplate communicating with the receiving section via a through hole and furnished with valves, component for initiation of mixture detonation and a gas valve for release of the explosion products, and an assembly for attachment of ammunition to the bedplate. EFFECT: expanded capacity, enhanced labour productivity and reduced cost. 6 cl, 5 dwg, 1 tbl, 1 ex

Description

 The invention relates to the field of disposal of weapons and is intended for the extraction of explosive materials from the shells of ammunition: artillery shells, mines, bombs, etc. for the purpose of their processing and use in the national economy. The invention can also be applied to the demilitarization of solid propellant rocket engines, cumulative perforators, downhole torpedoes and other similar explosive devices operating on solid explosives.

 Currently, various technical solutions for the disposal of ammunition are known.

 So, a demilitarization method is known, based on the smelting of an explosive charge due to induction heating of the ammunition body [1].

 In [2], a method is described for smelting a charge by exposing it to heated aqueous saline solutions.

 In accordance with the method [3], the extraction is carried out by dissolving the charge when exposed to a trotyl solvent.

 However, all these methods are intended for the disposal of ammunition equipped only with injection explosive compositions, the main component of which is TNT, while in the ammunition non-fusible explosives are also used, for the extraction of which these methods are not applicable.

 Unloading ammunition containing both fusible and non-fusible explosives provides a method and device based on the separation of the munition shell by a high-pressure liquid jet while simultaneously or subsequently exposing the explosive to a liquid stream of reduced pressure [4]. At the same time, the explosive is crushed and washed out of the ammunition chamber, followed by trapping.

 This technical solution is quite universal, but for its implementation it requires the use of unique and extremely expensive equipment based on the use of high-pressure liquid pumps and high-pressure hydro-jet equipment. In addition, such equipment is short-lived and practically unacceptable for the mass disposal of ammunition.

 More affordable in the implementation and providing the extraction of both fusible and non-fusible explosive materials is the technical solution described in [5] and adopted as a prototype. Disposal according to this technical solution consists in opening the ammunition chamber, crushing the explosive with a cutting tool and extracting the crushed material by supplying compressed air to the chamber. In the crushing process, the pressure of the cutting tool is controlled by preloading it in axial and radial directions. The closest to the implementation of the method and selected as a prototype is a device according to the patent of the Russian Federation under the name "Installation for equipping ammunition" [5]. The device includes a base plate with a through hole, an ammunition attachment unit, a kinematic drive unit of the cutting tool, a fragmented mass suction unit, and a receiving section.

 However, although this method of disposal does not involve the use of scarce and expensive equipment and hard-to-reach materials, it has serious drawbacks in terms of limited operational capabilities. To implement the method requires a rather bulky device with complex kinematic relationships, requiring constant adjustment, preventive and repair work. The method is applicable practically only in stationary (workshop) conditions, is characterized by a relatively low productivity and high cost of work.

 Thus, the claimed invention is aimed at solving the problem of expanding the operational capabilities of the method of disposal of ammunition, increasing productivity and reducing the cost of work. The technical result is expressed in the fact that the impact on the ammunition is carried out over its entire outer surface, as a result of which inside the explosive charge there is interference of shock waves and rarefaction waves moving in different directions, which increases the efficiency of charge fragmentation.

This is achieved due to the fact that in the method of disposal of ammunition equipped with a solid explosive charge, including opening the ammunition chamber, crushing the explosive charge and extracting the fragmented mass, according to the invention, the crushing is carried out by the shock wave generated during the explosion of the surrounding ammunition and at a given initial pressure of the combustible gas mixture. In this case, the strength of the explosive substance of the charge is preliminarily determined, the pressure necessary for crushing in the acting shock wave is found by its value, and the initial pressure of the combustible gas mixture is determined by the dependence of its detonation parameters on the parameters of the initial state, using the relation
P = P _o + {1- (C $\genfrac{}{}{0ex}{}{\text{2}}{\text{o}}$ / D ² )} • ρ _o D ² / (k + 1),
where P is the pressure in the shock wave,
P ₀ is the initial pressure of the gas mixture,
C ₀ - the speed of sound in the gas mixture in the initial state,
D is the detonation velocity of the mixture,
ρ _o - the initial density of the gas mixture,
k is the ratio of the heat capacity of the gas mixture at constant pressure to the heat capacity of the gas mixture at a constant volume.

 The exposure is carried out repeatedly, the combustible gas mixture is obtained at the place of its application by mixing in the explosive ratio of combustible gas and oxidizing gas, and also receive it at a stoichiometric ratio of combustible gas and oxidizing gas.

 To implement the method, a device for disposing of ammunition equipped with a solid explosive charge containing a base plate with a through hole, an ammunition attachment unit and a receiving section for explosive according to the invention is equipped with an explosive chamber sealed to the base plate in communication with the receiving section through the through hole and equipped with pipeline fittings for supplying components of a combustible gas mixture, an element for initiating detonation of the mixture and a gas valve Ia explosion products, and munition mounting assembly is provided with a sealing compound munition element to the base plate.

 It is the supply of the device with an explosive chamber sealed to the base plate and having pipe fittings for supplying the components of the combustible gas mixture and an element for initiating detonation of the mixture, and the supply of the attachment unit of the munition with the sealing element of the connection between the munition and the base plate that makes it possible to form a charge of gaseous explosive around the utilized munition in the form of a combustible gas mixture of the required composition under the required initial pressure and subsequent impact on ammunition by the shock wave generated by the explosion of this mixture. In this case, a shock-wave effect on the ammunition is carried out over its entire outer surface and interference of the shock waves and rarefaction waves inside the explosive charge is realized, which increases the crushing efficiency. In addition, the supply of the blast chamber with a gas valve for bleeding the products of the explosion makes it possible to effect repeatedly without disconnecting the blast chamber from the base plate. This allows us to conclude that the claimed method and device are interconnected by a single inventive concept.

 A comparative analysis of the claimed inventions and the prototype revealed a new set of essential features, due to a change in both the methods of the disposal of ammunition and the design used to implement the method of the device. Thus, the claimed objects meet the criterion of "Novelty."

 The essence of the solution is illustrated by the figures.

 In FIG. 1 shows a device for implementing the method with the installed ammunition.

 In FIG. 2 - filling the explosive chamber of the device with components of a combustible gas mixture.

 In FIG. 3 - initiation of detonation of the mixture in the explosive chamber.

 In FIG. 4 - crushing the explosive charge of the ammunition by the shock wave and pouring the crushed mass into the receiving section.

 In FIG. 5 is a graph of the pressure in the shock wave versus the initial pressure for a stoichiometric hydrogen-oxygen mixture (explosive gas).

 The device (Fig. 1) for the disposal of ammunition according to the claimed method consists of a base plate 1 with a through hole 2, an attachment unit for the ammunition 3, including a thrust ring 4, a sealing element 5 and a clamping element 6, an explosive chamber 7, jointed through a gasket 8 hermetically with a base plate 1 and equipped with pipeline fittings for supplying components of a combustible gas mixture, including a gas valve 9 for supplying combustible gas, a gas valve 10 for supplying an oxidizing gas and a control gas manometer 11, an initiation element I detonation 12 and a gas valve 13 venting products of the explosion, and the receiving section 14 with an extractable tank 15.

 The blasting chamber 7 is usually made of metal and may have a cylindrical, spherical, box-shaped or other suitable shape of the required volume. The camera is attached to the base plate 1 using bolts, hydraulic clamps or crank locking elements (not shown in the figure).

 The sealing element 5 of the ammunition attachment node, along with the gasket 8 in the base plate 1, serves to ensure hermetic isolation of the internal volume of the chamber from the environment, as well as to prevent the penetration of combustible gas mixture into the opened charging chamber of the ammunition. The material of element 5 can be conventional or vacuum rubber, vacuum putty, or highly viscous grease.

 VK-86 gas valves can be used as gas valves 9 and 10 for supplying components of a combustible gas mixture and valve 13 for venting explosion products. As an element for initiating detonation 12, a high-voltage automobile spark plug A17DV, F20D-1, etc. As a control pressure gauge 11, a gas pressure gauge MVShO-20.

 The method is carried out as follows.

Before starting work, a combustible gas mixture is selected for use. The most suitable combustible gas and oxidizing gas are selected. The fuel gas used can be relatively inexpensive hydrogen (H ₂ ), methane (CH ₄ ), acetylene (C ₂ H ₂ ), ethylene (C ₂ H ₄ ), propylene (C ₃ H ₆ ), propane (C ₃ H ₈ ), butane (C ₄ H ₁₀ ), etc. Oxygen or atmospheric air is used as an oxidizing gas. The basis for the selection of certain gases can be the required caloric content of the mixture, non-toxicity, availability of acquisition in the required quantity, etc. For selected gases from the reference literature, for example, [6], determine the percentage of combustible gas in the mixture, ensuring its reliable explosive conversion. The explosive concentration limits of a mixture of combustible gases with oxygen or air are currently well known. The table shows the data on the concentration limits of explosiveness for the most common combustible gases (see table at the end of the description).

 The data indicate the explosiveness of the mixtures in a wide range of variation of their components.

 Investigate the batch of ammunition to be disposed of and determine the compressive strength of the explosive charge. Strength is determined either by the technical documentation for these ammunition, or by conducting appropriate strength tests.

The strength of the explosive is determined by the pressure in the shock wave necessary for its crushing (it is taken equal to the compressive strength of the explosive or slightly larger than this value). The pressure in the shock wave depends on the composition of the mixture, the ratio of its components, the initial pressure and is determined by the expression known from explosion physics [6]
P = P _o + {1- (C $\genfrac{}{}{0ex}{}{\text{2}}{\text{o}}$ / D ² )} • ρ _o D ² / (k + 1),
where: P is the pressure in the shock wave,
P ₀ is the initial pressure of the gas mixture,
C ₀ - the speed of sound in the gas mixture in the initial state,
D is the detonation velocity of the mixture,
ρ _o - the initial density of the gas mixture,
k is the ratio of the heat capacity of the gas mixture at constant pressure to the heat capacity of the gas mixture at a constant volume.

The pressure in the shock wave P required for crushing the explosive in accordance with the above ratio determines its initial pressure P ₀ (pressure before detonation) for the selected gas mixture. The values of C ₀ , D, k during the calculations are taken from the corresponding reference literature, for example, [6]. For practical convenience, the dependence P (P ₀ ) for a particular gas mixture can be constructed in tabular or graphical form, for example, as shown in FIG. 5. The determination of the value of P ₀ in a production environment is greatly simplified.

 Thus, the composition and the necessary total initial pressure of the combustible gas mixture are found.

By the percentage of gases in the mixture and its total initial pressure, the partial pressure of each gas in the pressure P ₀ created by them is determined. (For example, if the total initial pressure of the mixture is P = 5 atm, and its composition is 66% of combustible gas + 34% of the oxidizing gas, then the pressure of the combustible gas in the mixture should be 3.3 atm, and the oxidizing gas - 1.7 atm .)
(The required initial pressure of the combustible gas mixture can be determined purely empirically. To do this, a series of experiments is carried out with a variation of the initial pressure of the mixture and the pressure value is determined at which an acceptable fragmentation of the explosive charge occurs by the action of the shock wave generated during detonation).

 Ammunition with an opened charging chamber is installed on the base plate 1 in the thrust ring 4 vertically, opened side down (Fig. 1). Using the clamp element 6, the ammunition is fixed. An explosive chamber 7 is mounted on the base plate 1 and articulated with the plate using bolts, hydraulic clamps, etc. (not shown in the figure). The element 5 and the gasket 8 provide a tight seal of the internal volume of the chamber from the environment.

Through the gas valve 9, connected by means of a dyurit hose to the gas line or a cylinder with compressed gas, the blast chamber is filled with combustible gas at the required pressure (Fig. 2). Through the gas valve 10, also connected via a dyurite hose to the gas line, a compressed gas cylinder or an air compressor, the explosive chamber is filled under the required pressure with an oxidizing gas. The gas pressure is set using external gas pressure regulators and controlled using a gas pressure gauge 11. The total gas pressure is P ₀ . The sequence for filling the blast chamber with gases can be any: first with combustible gas, and then with an oxidizing gas, or first with an oxidizing gas, and then with combustible gas.

 After filling the chamber 7 with gas components and obtaining a combustible gas mixture of the required composition under the required initial pressure, detonation of the mixture is initiated (Fig. 3). For this, a high voltage pulse is supplied to the initiation element 12. Inside the chamber 7 there is a high-voltage electric discharge that excites detonation.

 The shock wave through the shell of the munition affects the explosive charge and crushes it (Fig. 4). The crushed mass through the hole 2 in the base plate 1 is poured into the tank 15 of the receiving section 14.

 Open the gas valve 13 and pit the explosion products from the blast chamber 7. The container 15 is removed and the fragmented explosive is removed. The explosive chamber 7 is disconnected from the base plate 1 and the empty ammunition casing is released from the attachment point.

 If, after a single exposure, no fragmentation of the charge occurred or the degree of fragmentation was insufficient to completely pour out the fragmented mass from the projectile chamber, then the effect can be repeated or even several times. For this, it is not necessary to disconnect the explosive chamber from the base plate, but only after the previous detonation, detonate the products of detonation, fill the chamber with fresh combustible gas mixture and again undermine.

 Here, the operation of the device is described by the example of the disposal of a single munition. In a real device, explosives can be extracted simultaneously from several mutually identical munitions in one blast. The essence of the proposed solution does not change, the sequence of operations remains the same.

By varying P ₀ (due to a simple increase or decrease in the initial pressure of the components of the gas mixture in the explosive chamber 7), pressures in the shock wave of up to tens and hundreds of atmospheres can be realized and thereby create the necessary conditions for efficient crushing of a relatively low-strength material, such as a chemical explosive .

 In addition, the impact on the ammunition is carried out over its entire outer surface. As a result, interference of the shock waves and rarefaction waves moving in different directions occurs inside the explosive charge. The crushing efficiency is further increased.

 This disposal method is also relatively safe from the point of view of an ammunition explosion. For crushing an explosive, a pressure of only tens of atmospheres is sufficient, while for excitation of detonation, a pressure in the acting shock wave of tens of thousands of atmospheres is required, i.e. three orders of magnitude larger.

 The claimed technical solutions can simplify the process of extracting explosives from ammunition, increase the autonomy of the method and widely use it in non-stationary, including polygon conditions.

An example of a specific implementation of the method
An artillery shell of 152 mm caliber, equipped with a bursting charge of 80/20 ammotol, was used as a utilized munition.

For technical documentation determined that Amatol 80/20 has a compressive strength σ _in = 56 kgf / cm ^2.
After removing the fuse, the shell of the projectile was opened, removing the screw head.

A stoichiometric hydrogen-oxygen mixture (2H ₂ + O ₂ — explosive gas) was selected as a combustible gas mixture. The percentage composition of the mixture: 66% hydrogen + 34% oxygen.

We determined by the explosive strength of the charge the pressure necessary for crushing in the acting shock wave. We took it equal to P = 70 atm, i.e. somewhat larger tensile strength σ _in = 56 kgf / cm ² .
Based on the analytical dependence of the detonation parameters of gas mixtures on the parameters of the initial state [6], a graph of the dependence of the pressure in the detonation wave on the initial pressure — P (P ₀ ) shown in FIG. 5.

Using the value of the required pressure in the shock wave P = 70 atm using the constructed graph (Fig. 5), we determined the required initial pressure of the mixture P ₀ (shown in the graph by arrows). Received P ₀ ≈ 5 atm.

 The projectile was mounted on the base plate hermetically in the attachment point vertically, opened part down.

A cylindrical explosive chamber with an internal volume of 0.27 m ^{3 was} mounted on the base plate and hermetically connected to the plate through a rubber gasket using 12 M24 bolts.

 The chamber was equipped with two gas valves VK-86 for supplying components of a combustible gas mixture, a gas pressure gauge MVShO-20, a high-voltage spark plug A17DV and a valve for venting the products of the VK-86 explosion.

 One of the gas valves was connected using a dyurite hose to a compressed oxygen cylinder.

 The blast chamber was purged with oxygen.

 The chamber was filled with oxygen to a pressure of 1.7 atm.

 The second gas valve was connected using a dyurite hose with a compressed hydrogen cylinder.

 The blast chamber was filled with hydrogen to a total pressure of 5 atm (the proportion of hydrogen in the total pressure was 3.3 atm).

 The pressure in the blast chamber was monitored using a MVShO-20 gas manometer.

A stoichiometric hydrogen-oxygen mixture of 2: 1 (2H ₂ + O ₂ ) was formed in the explosive chamber.

 A 6 kV voltage pulse was applied to the A17DV spark plug connected by a radio frequency cable RK-75-4-11 with a high-voltage pulse generator.

 A high voltage discharge has occurred in the cavity of the explosive chamber. The detonation of the mixture with a pressure in the wave front of ~ 70 atm was excited.

 The shock wave through the wall of the projectile acted on the explosive charge and crushed it (figure 4). The crushed mass through a hole in the base plate poured out of the projectile chamber into the extractable capacity of the receiving section.

The valve for venting the explosion products was opened and the gaseous products of detonation of the mixture were vented from the explosion chamber. The explosion produced non-toxic detonation products, consisting mainly of water vapor H ₂ O, hydroxyl group OH, atomic and molecular oxygen and hydrogen: O, H, O ₂ , H ₂ .

 The container was removed and the fragmented explosive was removed.

 When using this method, the preparation of an explosive substance (combustible gas mixture), the explosion of which produces an impact shock wave, is carried out directly at the place of its use. The preparation of the mixture itself, as well as the delivery and storage of its components are relatively safe procedures. The shock wave generated during the explosion of gas mixtures is safe from the point of view of exciting detonation of blasting explosives, which are usually equipped with ammunition. In addition, compressed combustible gases, compressed oxygen or air, have a relatively low cost of their production and content. All this makes this method more economical and safe and opens up additional opportunities for its wider use.

 Compared with the known technical solutions for a similar purpose, the claimed object does not require hazardous preparatory work, is environmentally friendly, does not involve the use of bulky and expensive equipment and can be used both in stationary and in landfill conditions, which makes it more suitable for high technology.

Literature
1. Patent of Russia N 2045743, cl. F 42 B 33/00, C 06 B 21/00, publ. 10/10/95 g

 2. Patent of Russia N 2045744, cl. F 42 B 33/00, C 06 B 21/00, publ. 10/10/95 g

 3. Patent of Russia N 2031896, cl. F 42 B 33/00, C 06 B 21/00, publ. 03/27/95

 4. German patent N 4128703, cl. F 42 B 33/06, B 08 B 3/02, publ. 03/04/93

 5. Patent of Russia N 2046284, cl. F 42 B 33/00, 33/06, C 06 B 21/00, publ. 10.20.95, the prototype.

 6. K.P. Stanyukovich Explosion Physics, ed. 2nd. M .: Nauka, 1975.

Claims (6)

 1. A method of disposing of ammunition equipped with a solid explosive charge, including opening the munition chamber, crushing the explosive charge and extracting the fragmented mass, characterized in that the crushing is effected by the shock wave generated during the explosion surrounding the ammunition and at a given initial combustible pressure gas mixture. 2. The method according to claim 1, characterized in that the strength of the explosive charge is determined first, the pressure necessary for crushing in the acting shock wave is determined by its size, and the initial pressure of the combustible gas mixture is determined by the dependence of its detonation parameters on the parameters of the initial state, using for this ratio
P = P _o + {1- (C $\genfrac{}{}{0ex}{}{\text{2}}{\text{o}}$ / D ² )} • ρ _o D ² / (k + 1),
where P is the pressure in the shock wave;
P _o - the initial pressure of the gas mixture;
C _o is the speed of sound in the gas mixture in the initial state;
D is the detonation velocity of the mixture;
ρ _o - the initial density of the gas mixture;
k is the ratio of the heat capacity of the gas mixture at constant pressure to the heat capacity of the gas mixture at a constant volume.  3. The method according to any one of claims 1 and 2, characterized in that the effect is carried out repeatedly.  4. The method according to any one of claims 1 to 3, characterized in that the combustible gas mixture is obtained at the place of its application by mixing in the explosive ratio of combustible gas and oxidizing gas.  5. The method according to any one of claims 1 to 4, characterized in that the combustible gas mixture is obtained at a stoichiometric ratio of combustible gas and oxidizing gas.  6. A device for disposing of ammunition equipped with a solid explosive charge, comprising a base plate with a through hole, an ammunition attachment unit and a receiving section for explosive, characterized in that it is equipped with an explosive chamber sealed to the base plate in communication with the receiving section through a through hole and equipped with pipeline fittings for supplying components of a combustible gas mixture, an element for initiating detonation of the mixture and a gas valve for venting the products of the explosion a and munition mounting assembly is provided with sealing compound munition element to the base plate.

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