RU2487855C1 - Powder charge for light-gas gun - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to rifles and specifically to a powder charge for a light-gas gun or firearm. The powder charge contains gaseous borane and phosphine or a solution of liquid borane and phosphine and is meant to be put under pressure in a cartridge chamber or bore in form of a metal or composite cylinder, actuation of which is triggered by a heat source lying in the breech end or the front end of the bore, inside or outside it. Use of catalysts in form of carbon, soot, graphite or methane is also possible, as well as retarders such as hydrides, having a negative enthalpy of formation, i.e. an endothermic decomposition reaction, e.g. hydrides of beryllium, lithium, aluminium, calcium or a mixture thereof. The heat source if a capsule, an electric coil, a spark or an explosive or cumulative charge, lying inside or outside the bore.

EFFECT: invention provides high muzzle velocity, simplifies the design of the gun, increases firing speed, reduces the weight of the gun and cost of firing.

9 cl

Description

The invention relates to artillery - to light-gas guns with a high initial speed and to firearms - to sniper rifles.

Weapons are known in which a powder gas compresses a light gas (hydrogen), which then accelerates the projectile. Since the speed of sound in light gas is greater than in powder gases, a higher initial velocity of the projectile is achieved, see Internet, Wikipedia.

The disadvantage of this tool is the structural complexity, high weight, high cost of a shot, very low rate of fire.

Meanwhile, shells could be fired from conventional or almost ordinary guns with an initial speed of about 3000 m / s, if the powder produced even less heat, but only hydrogen and solids. Even at ordinary temperature, the speed of sound in hydrogen is 1330 m / s, and with slight heating it increases accordingly.

Such a powder, one can even call it gas powder or liquid powder, can be a gas mixture under the pressure of boranes and phosphines or a solution or emulsion of liquid borane and phosphine. Of boranes, diborane has the highest hydrogen content. Although tetraborane has a better liquefaction (boils at 18 degrees C), but it contains a lower percentage of hydrogen. Diborane and fofin are liquefied in approximately the same way - although diborane has a lower boiling point, it also has a lower critical pressure.

Consider the “burning” reaction of such gunpowder using diborane and phosphine (mono) as an example. When the reaction is initiated by a heat source (capsule), the exothermic decomposition of diborane (up to 300 degrees C) occurs first with a heat release of 38.5 kJ / mol, after which the released boron interacts with two phosphine molecules:

В2Н6 + 2РН3 = 2ВР + 6Н2 + 842.5 kJ / mol

That is, the specific heat release is 8.77 kJ / g, which is about twice as much as that of gunpowder. The proportion of hydrogen by weight of reacting substances is 12.5%. The conditional equivalent indicator "K" equal to the product of energy release by the fraction of hydrogen is 1.10. Approximate calculations show that the reaction temperature will be at a constant pressure of 2000 degrees C, and at a constant volume of 2400 degrees C. Since boron reacts with phosphorus above 1200 degrees, the whole reaction goes like an avalanche, that is, very quickly.

The formation of boron phosphide is more intense in the presence of a reducing agent. Such may be hydrogen evolved. To increase the reaction rate, the presence of finely divided coal, soot, graphite, or a small amount of methane (0.0001-1% by weight of the reacting substances), or a mixture thereof, is desirable. At temperatures above 1100 degrees C, methane decomposes exothermically with the release of two molecules of hydrogen and carbon in the form of soot, which will be a catalyst for the formation of boron phosphide.

As can be seen from the reaction, the stoichiometric ratio of diborane and phosphide should be 27.67: 68.00 and 12.1 g / m of hydrogen will be released. In reality, up to 10% deviations in one direction or another are possible due to the difference in reaction rates. That is, the stoichiometric ratio in percent is 28.92: 71.08, and at the same time 12.5% of hydrogen will be released in relation to the initial mass.

If the reagents are in a charge in a gaseous state, the charge temperature should be monitored, since a liquid phase can form at a low temperature, which will lead to the separation of the charge components and. possibly a decrease in the reaction rate (a series of experiments is required). For diboran, the critical temperature is 16.7, and for phosphine (mono) 51.3 degrees C.

Another reaction of the components is possible, for example tetraborane with diphosphine:

V4N10 + 2R2N4 = 4VR + 9N2 + 1641.6 kJ

That is, the energy release of 8.86 kJ / g, hydrogen 9.79%, K = 0.87. As you can see, less hydrogen will be released, but it will have a higher temperature. Liquid components must be in dissolved form or in the form of an emulsion.

The charge is initiated by the heat source located inside the shell in the form of an electric spiral, spark, capsule, or an explosive or cumulative charge located outside or inside the sleeve.

The reaction rate may be too high, so it can be controlled by the content of coal, soot, graphite or methane. By reducing or eliminating their presence, the desired reaction rate can be achieved.

But, if it turns out to be too large even in the absence of catalysts, then reaction inhibitors should be used, which in this case can be hydrides or their mixture having a negative formation enthalpy, that is, an endothermic decomposition reaction in an amount of 0.01-99%, or large the amount of methane (much more than is necessary for catalysis), or a mixture of them in an amount of 1 to 99% (this percentage is different for each gun). Among hydrides, beryllium, lithium, aluminum, and calcium hydrides have a negative enthalpy of formation. The largest percentage of hydrogen contains beryllium hydride.

But hydrides with a small positive enthalpy of formation (less than the thermal effect of the main reaction between diborane and phosphine), for example, beryllium borohydride or the same borane or phosphine in an amount larger than necessary for the main reaction, can also be used as moderators.

It is advisable to apply the method of controlling the reaction rate that will reduce the specific heat to the least extent.

But it is important to ensure that moderators do not emit gaseous substances with a high molecular weight, such as phosphorus, potassium chloride, lithium, at the operating temperature. Otherwise, the speed of sound in this mixture of gases will decrease significantly.

An additional requirement is imposed on the gun - the complete tightness of the charging chamber and the shutter (if any). Also, a projectile must be inserted tightly into the barrel, for which it can have a rear o-ring with a skirt facing back and / or an elastic cuff (this is my separate invention). Gaseous or liquid gunpowder can be supplied to the chamber through one or two holes in the chamber. And it can be carried out with the help of a sleeve in the form of a durable metal or composite cylinder. To activate a charge with such a sleeve on the front end of the sleeve inside or outside it must be a cruciform or star-shaped perforating miniature cumulative charge.

The charge works like this: the charge can be powered by an internal heat source of sufficient temperature - a capsule, electric coil, spark, etc. and if the charge is in the sleeve, it can be activated by a small explosive or cumulative charge located outside or inside the sleeve.

In the case with a sleeve, a perforating charge opens the front end of the cylinder sleeve and sets fire to the reagents of gunpowder. The resulting hydrogen has a sound speed of 3900 m / s. The projectile will receive an initial speed of about 3700 m / s. And since the kinetic energy is proportional to the square of the speed, the breakdown force of the projectile will be approximately 15 times higher.

The only drawback of such gunpowder is its strong unmasking effect - the released hydrogen will ignite in air, and since it contains solid nitride particles, this flame will be clearly visible.

Claims (9)

1. A powder charge for a light-gas weapon, including reactants in the form of gaseous borane and phosphine or a solution of liquid borane and phosphine, which are pressurized in a charging chamber or sleeve in the form of a metal or composite cylinder, the triggering of which is initiated by a heat source located in the breech of the weapon or on the front end of the sleeve inside or outside of it. 2. The charge according to claim 1, characterized in that it contains 0.0001-1% by weight of the reacting substances of finely divided coal, and / or soot, and / or graphite, and / or methane. 3. The charge according to claim 1, characterized in that it contains borane and phosphine in a stoichiometric ratio of 28.92 ± 10% and 71.08 ± 10%, respectively. 4. The charge according to claim 1, characterized in that the heat source is an explosive or cumulative charge located inside or outside the sleeve. 5. The charge according to claim 4, characterized in that the cumulative charge is a cross-shaped or star-shaped perforating cumulative charge. 6. The charge according to claim 1, characterized in that the heat source is a capsule, electric coil or spark. 7. The charge according to claim 1, characterized in that it contains reaction inhibitors, such as hydrides having a negative enthalpy of formation, that is, an endothermic decomposition reaction, for example, hydrides of beryllium, lithium, aluminum, calcium, or a mixture thereof in an amount of 0.01-99 %, or methane or a mixture thereof in an amount of from 1 to 99%. 8. The charge according to claim 1, characterized in that it contains hydrides with a positive enthalpy of formation less than the thermal effect of the main reaction. 9. The charge according to claim 1, characterized in that the moderator is a heat-resistant and passive to reacting components substance in a finely dispersed state, for example aerosil - finely divided silica, dry iron oxide, zinc.