RU2392579C1 - Method of killing shock wave in underwater explosion - Google Patents

Abstract

FIELD: blasting works. ^ SUBSTANCE: invention relates to methods intended for killing shock wave in underwater blasting operations. Proposed method consists in setting curtains of air bubbles. Curtain of air bubbles is produced from hollow glass microspheres premixed with fluid in amount of 10% to 30% of its volume for fluid to be weightened to density of 1.2-1.3 g/cm3 and higher. Fluid is used which, after cross-linking, has viscoelastic properties and relaxation period at straining effects equal to at least hydraulic shock wave effect time interval. Then mix is placed into soft container and arranged above explosive charge. ^ EFFECT: higher safety of blasting works underwater due to reliable localisation of explosion zone. ^ 1 dwg

Description

The invention relates to methods for damping a shock wave during an underwater explosion during blasting under water.

A known method of damping a shock wave during an underwater explosion, which consists in placing a shielding curtain on the path of the shock wave in the water (see the description of the invention of the Russian Federation according to patent No. 2087847, IPC F42D 5/00 from 1995.12.28).

With a small depth of the pond, a shielding curtain with positive buoyancy in the known method is created from immersed in water nets or shells of a permeable fabric filled with hollow spheres and / or pieces of foam, and / or expanded clay gravel, and with a greater depth, with loads giving the curtain held floats, negative buoyancy, the curtain is stabilized under water with anchors.

The method is complicated, since it is difficult to install a screening curtain having a complex structure, in the presence of flow.

In addition, after blasting, the reservoir may be polluted with hollow spheres, and / or pieces of foam, and / or expanded clay gravel, which worsens the environmental situation.

A known method of damping a shock wave during an underwater explosion during blasting, adopted as a prototype, which consists in installing curtains of air bubbles between the charge and the protected object (see V.V. Galkin, R.A. Gilmanov, I.Z.Drogoveiko Blasting operations underwater. M.: Nedra, 1987, pp. 74-75).

To protect equipment and structures from water shock during underwater explosions in a known method using curtains that are artificially created using compressor units and pipes with openings for air outlet.

The disadvantage of this method is the complexity of the formation (placement) of curtains of air bubbles, as well as their placement at great depths under water and in the presence of a current, which makes it difficult to use.

The technical task of the proposed method is to simplify blasting under water and increase the reliability of its use, as well as providing protection against destruction of the near zone during blasting by reliable localization of the explosion zone.

The technical problem is solved in that the method of damping a shock wave during an underwater explosion consists in installing curtains of air bubbles, while the curtain of air bubbles is obtained from hollow glass microspheres, which are pre-mixed with liquid in an amount of 10-30% of its volume, then liquid weighted to a density of 1.2-1.3 g / cm ³ or more, moreover, a liquid having viscoelastic properties after crosslinking with a relaxation time during deformation of at least equal to the period of action is used as a liquid water shock wave, then the mixture is placed in a soft container and set it over a charge of explosives.

The proposed method allows you to isolate the charge with a viscoelastic fluid, and the presence of hollow glass microspheres allows not only to provide conditions for an explosion, but also to quench the energy of the shock wave:

- due to multiple refraction of a hydroshock wave at the water (liquid) - air interface;

- due to the destruction and collapse of glass microspheres;

- due to the compression of air bubbles resulting from the destruction of glass microspheres.

The proposed composition can be used at any depth and at any temperature.

The method is illustrated in the drawing, which schematically depicts the placement of charge and liquid for quenching a water shock during underwater blasting.

The method is implemented in the following way.

First, a viscoelastic fluid 1 is prepared, for example, an aqueous solution of polyacrylamide with a content of polyacrylamide of 0.5-1.0% is used, then hollow glass microspheres are added in an amount of 10-30% of its volume and mixed until a homogeneous mixture is obtained. Then the mixture is weighed to more tightly adhere container 2 to the explosive charge 3, for example, barite (BaSO ₄ ) to a density of 1.2-1.3 g / cm ³ , and an aqueous solution of alumina sulfate 1.0-3 is used to crosslink the polyacrylamide , 0% volume, which is introduced with constant stirring.

Then the weighted liquid 1 with hollow glass microspheres is placed in a soft container 2, which is placed over the charge 3 of explosives.

The composition of a viscoelastic fluid for quenching a shock wave based on polyacrylamide crosslinked by cations of salts of polyvalent metals with a content of polyacrylamide of 0.5-1.0% is environmentally friendly and does not harm the environment after the container is destroyed.

Claims (1)

The method of damping a shock wave during an underwater explosion consists in installing air bubble curtains, characterized in that the air bubble curtain is obtained from hollow glass microspheres, which are pre-mixed with liquid in an amount of 10-30% of its volume, then the liquid is weighted to a density of 1 , 2-1.3 g / cm ³ or more, moreover, as a liquid, a liquid is used that has, after crosslinking, viscoelastic properties with a relaxation time during deformation of at least equal to the period of the shock wave , then the mixture is placed in a soft container and set it over a charge of explosives.

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