RU158999U1 - DEVICE FOR DETERMINING THE WATER PROTECTION LEVEL OF THE POWDER CHARGES OF THE ARTILLERY AMMUNITION - Google Patents

Abstract

A device for determining the level of moisture protection of powder charges of artillery ammunition, containing a metal case with a flange and a sealed outlet pipe for wiring, a sealing unit made of a cardboard cover with a layer of adhesive-sealant on its side and outer end surface, a metal clamping ring with clamping bolts, and sensors of temperature and humidity of gunpowder.

Description

The proposed device for determining the level of moisture protection of powder charges of artillery ammunition belongs to the field of measurement technology and is intended to safely determine in laboratory conditions the rate of change of moisture of a powder charge based on tests of the mass of gunpowder reduced by ten or more times in real time without leakage during tests during the speed of moistening (drying) of gunpowder, identical with a natural product.

The degree of tightness of powder charges in artillery ammunition is not ideal, since moisture can diffuse through such effective sealants as polyethylene and others [1]. During long-term storage of artillery ammunition, powder charges under the influence of temperature and humidity of the surrounding air may become wet or dry due to diffusion of water vapor through the sealant and their adsorption (desorption) of gunpowder. A change in the moisture content of the powder leads to a change in the initial velocity of the projectile, the firing range and the probability of hitting the target. Currently, the degree of moisture protection of products is assessed on the basis of determining the vapor permeability of materials used as sealants [2], testing airtight containers [3], and testing the products for climatic resistance [4].

A device [2] is known for determining the vapor permeability of sheet materials by the gravimetric method, consisting of a test cup with a drying agent, a test sample of sheet material, an annular template and a protective cover and designed to determine the vapor permeability of the test material by weighing the device. The disadvantages of the device for determining the vapor permeability are the determination of the vapor permeability of materials without taking into account the influence on the moisture protection of the product of its design, the product is not protected from moisture in the tests, therefore, the tests do not provide information on the rate of wetting (drying) of the product stored in a conditionally sealed volume.

A device for testing containers for leaks [3], consisting of a vacuum chamber partially filled with water, a vacuum gauge and designed to determine the tightness of immersed in water containers by the presence of air bubbles in water when creating a vacuum in the chamber or overpressure in the container. The disadvantages of the device for testing containers for its tightness is the inability to determine by the test results the rate of wetting (drying) of the product that will be stored in this container, the test conditions do not correspond to the storage conditions of the product.

As a prototype of a device for determining the moisture protection level of gunpowder charges of artillery ammunition, a full-scale product (gunpowder charge in a sleeve [5]), shown in Figure 1, consisting of a metal casing 1, a weight of gunpowder 2 and a sealing assembly from a cardboard cover 3 with a sealant layer 4 was adopted and intended as an object for testing moisture resistance in a climatic chamber. The disadvantage of a full-scale product (powder charge in a sleeve) as an object for testing moisture resistance is the increased risk of testing due to the large mass of gunpowder (2 ... 5 kg) in one product, the difficulty of simultaneously testing several large-sized products at different temperatures and humidity air, the determination of the moisture content of the powder is possible during depressurization of the propellant charge after removing the cardboard cover with sealant. Upon receipt of information about the state of the powder for several time intervals, it is necessary to repeatedly depressurize and re-seal the charge in the sleeve. Repeated depressurization of the propellant charge leads to a change in the test conditions, which may affect the final results. The determination of the temperature and humidity of the powder is carried out non-remotely, i.e. in direct contact of the tester with the product, which increases the danger to the tester. Tests of gunpowder relate to work of increased danger (Safety rules when working with missiles and ammunition at artillery arsenals, bases and warehouses. - M.: Military Publishing House, 2006). When testing gunpowders, their self-ignition is possible due to their chemical decomposition, accumulation of charges of static electricity and other external factors [6]. The chemical decomposition of gunpowder raises its temperature, so temperature control is necessary to ensure the safety of the tests. Thus, increasing the safety of testing a powder charge for moisture protection is possible by reducing the mass of the tested powder by ten or more times and continuous remote monitoring of the parameters of the powder (temperature and humidity).

The technical task of the utility model is a device for determining the moisture protection level of powder charges of artillery ammunition, designed to determine in laboratory conditions the rate of change in moisture of powder charges based on tests of the mass of gunpowder reduced by ten or more times in real time without leakage during tests at the same full-scale product of the speed of moistening (drying) of gunpowder.

The technical result of the proposed utility model is to increase the safety of testing powder charges for their moisture resistance by reducing the mass of the test powder by a factor of ten or more, and also by continuously and remotely monitoring the temperature and humidity of the powder during testing in real time without violating the tightness in the test process at the same rate of moistening (drying) as the full-scale product.

The specified technical result is achieved by the fact that for the safe determination in laboratory conditions of the level of moisture protection of the powder charges of artillery ammunition based on tests of the mass of gunpowder reduced by ten or more times while continuously and remotely monitoring the temperature and humidity of the gunpowder in real time without leakage during the tests at equal to the natural product speed of humidification (drying) of gunpowder, a device is used to determine the level of moisture protection of powder charges of artillery Series of ammunition (Figure 2), consisting of a metal casing 1 with a flange and a sealed outlet pipe 4 for the output of electrical wiring, reduced by ten or more times the weight of gunpowder 2, the sealing unit from the cardboard cover 7 (Figure 3) with a sealant layer 9 and 10, pressure metal ring 8 with pressure bolts 6, temperature sensors 5 and humidity 3 with electrical wiring.

The technical problem was solved on the basis of the development of a mathematical model of the process of moisture exchange with the environment of the powder charge in the housing (sleeve) with a sealing unit and the development of a physical model of the full-scale product. The physical model provides the same rate of moistening (drying) of the powder charge with the full-scale product.

The rate of wetting (drying) of the powder charge in a conditionally hermetic volume is described by the equation

where c is the moisture content of gunpowder;

t is the time;

k is the constant of the rate of moistening (drying of the powder), depending on temperature;

b is the coefficient in the equation for the equilibrium moisture content of gunpowder on the relative humidity φ

m is the mass of gunpowder in the housing (sleeve);

d is the thickness of the sealant layer;

p is the moisture permeability coefficient of the sealant;

S is the surface area of the sealant through which moisture diffuses

P _us = saturated vapor pressure, depends on temperature.

From equation (1) it follows that the rate of moistening (drying) of the powder charge in the full-scale product and in the proposed device (physical model) will be the same under the following conditions:

gunpowder in a full-scale product and in the proposed device has the same properties, that is, of the same brand and lot;

the temperature and relative humidity in the climate chamber during the tests of the full-scale product and the proposed device are the same;

in a full-scale product and in the proposed device, a sealant of the same brand with the same layer thickness is applied to the outer end surface of the lid;

the ratio of the mass of gunpowder to the surface of the sealant through which moisture diffuses, for a full-scale product and the proposed device should be equal

where m _ed. and m _device - the mass of the tested powder in the full-scale product and in the proposed device;

S _ed. and S _device - the surface area of the sealant in the full-scale product and in the proposed device.

зависит от массы порохового заряда и калибра боеприпаса.Attitude

depends on the mass of the powder charge and the caliber of the ammunition.

To determine the rate of wetting (drying) of the powder charge using the proposed device, the test powder sample is calculated according to formula 4. For powder charge No. 1, the D-30 122-mm howitzer, the initial data are equal: the mass of the tested powder in a full-scale article m _ed. = 1,990 kg, the surface area of the sealant in the full-scale product S _ed. = 123 cm ² , the diameter of the sealant in the proposed device D _device. = 3 cm. According to the formula (3), the surface area of the sealant in the proposed device S _{device is} calculated _. = 7.1 cm ² . According to formula 4, the mass of the tested powder in the proposed device m _{device is} calculated _. = 7.1 · 1.990 / 123 = 0.115 kg = 115 g. The mass of the tested powder decreased by 17 times.

A hinge of the test powder 2 is poured into the housing 1, the cardboard cover 7 is cut out according to the shape shown in Figure 3, the side surface of the cover is covered with a layer of adhesive-sealant 10, the cardboard cover is fixed to the flanges of the housing using the pressure ring 8 and bolts 6, and regular sealant 9 is applied on the outer end surface of the cover 7, the assembled device is installed in a climatic chamber (thermostat), connected to measuring equipment and remotely in real time the temperature readings are taken from the sensors powder charge humidity.

The rate of humidification (drying) in absolute value in the studied time interval is calculated by the formula

where c ₁ , c ₂ is the moisture content of the powder charge at the initial t ₁ and final t ₂ time instants of this interval.

The developed device allows to increase the safety of determining in laboratory conditions the level of moisture protection of gunpowder charges of artillery ammunition based on tests of ten or more times reduced mass of gunpowder and remote monitoring of the temperature and humidity of gunpowder in real time without breaking the seal during tests at the same moistening rate as the full-scale product (drying out) gunpowder.

Used Books

1. Reutlinger S.A. Permeability of polymeric materials. M: Chemistry, 1974.- 272 p.

2. GOST 21472-81. Sheet materials. Gravimetric method for determining vapor permeability.

3. GOST R 51827-2001. Test methods for tightness and hydraulic pressure.

4. GOST R 51369-99. Test methods for resistance to climatic external influences of machines, devices and other technical products. Humidity Testing.

5. Ivanov VA, Gorovoy Yu.B. Device and operation of artillery weapons of the Russian army: Textbook. Tambov: Publishing house of Tamb. state technical University, 2005 .-- p. 107-108.

6. Production and operation of gunpowder and explosives [Text]: textbook for high schools / V.K. Maryin, N.M. Boklashov, B.G. Romanenko, L.N. Gavrilenko, A.B. Terentyev; Ministry of Defense of the Russian Federation, GRAU of the Ministry of Defense of the Russian Federation. -Penza: PAII, 2005 .-- 350 p.

Claims (1)

A device for determining the level of moisture protection of powder charges of artillery ammunition, containing a metal case with a flange and a sealed outlet pipe for wiring, a sealing unit made of a cardboard cover with a layer of adhesive-sealant on its side and outer end surface, a metal clamping ring with clamping bolts, and sensors of temperature and humidity of gunpowder.

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