RU2087846C1 - Arrangement for suppression of shock waves at underwater explosions - Google Patents

Abstract

FIELD: safety at underwater blasting. SUBSTANCE: the arrangement has a horizontally arranged net with ropes and cords fastened around its edges, they are grouped with a density growing in the direction of passage of shock waves. The net is made of material of a lower density, and the ropes and cords of material of a higher density than the water density. EFFECT: enhanced safety. 1 dwg

Description

 The invention relates to blasting and is intended to extinguish shock waves (HC) during underwater explosions.

 The protection of engineering structures and ichthyofauna by a curtain of air bubbles is known [1] The main disadvantage of veil bubbles is the inability to protect HC objects placed above a charge and under a charge, since only vertical bubble curtains are created from the perforated tubes by bubbling air.

 Screens for extinguishing hydrocarbons during underwater explosions can be created not only from a gas-liquid medium, since any physical and mechanical heterogeneity of the medium along the path of the hydrocarbon leads to their weakening. In a homogeneous medium of water, screens for attenuating an HC can serve as a system of solids of a certain structure placed in water around a source of HC.

It is known to extinguish airborne hydrocarbons in mine workings with shields from free hanging flexible elements (ropes, ropes) made of synthetic fibers [2]
The drawing shows a diagram of a device for damping hydrocarbons when deepening the bottom of the fairway, where 1 horizontal screen in the form of a grid formed by ropes made of synthetic fibers, 2 -packets of vertical freely hanging ropes with a density increasing in the direction of passage of the hydrocarbons surrounding the explosive charge (BB) from all sides, 3 — charge of the explosive, 4 cables, 5 floats securing the device in the position required to extinguish the HC. If there is a current, the device is fixed with anchors.

 Depending on the shape (concentrated or linear) of the explosive charge and its mass, the dimensions of the device vary, therefore, for the versatility of the device, screens are assembled from modules interconnected by flexible connections.

 The lightest construction is made of ropes made of synthetic fibers, of which polypropylene and polyester fibers are the most durable.

Polypropylene fibers with a density of 0.91 g / cm ^{3 are} recommended for the manufacture of ropes or cords forming a horizontal mesh 1.

 Positive buoyancy will ensure the orientation of the grid in the form of a dome over the charge with the exception of undesirable sagging of the grid.

Polyester fibers with a density of 1.3 1.4 g / cm ³ used in the manufacture of ropes, cables, drive belts are recommended for vertically oriented ropes 2. Screens made of synthetic materials will not require floats of 5 large volumes to ensure buoyancy of the device.

 Example. On the shore or on a boat, a device is assembled from standard modules, connecting the elements forming a screen of horizontal mesh 1 by flexible connections between each other. Packs of freely hanging ropes 2 are attached to the resulting mesh 1 of the required size, placing them around the perimeter of mesh 1.

 Ropes 4 are attached to the grid 2 for floats 5. Other ropes (not shown in the diagram) are connected to the charge 3 by passing the ropes through the holes in the grid 1 and fixing them in the grid. The length of the cables from the charge (counting from the horizontal grid 1 to the bottom of the reservoir) slightly exceeds the length of the vertically hanging ropes 2.

 The device from the screens for extinguishing hydrocarbons together with a charge of explosives with the help of winches or ship cranes is lowered into the water. When reaching the explosive charges of the bottom (easily determined), the cables 4 are fixed in this position by the floats 5. In this case, the freely hanging vertical ropes 2 do not reach the bottom. The device, placed in this way and fixed by the floats 2, is ready for use.

 After the explosion of the explosive charge, the device is lifted out of the water for further repeated use.

 The main advantages of the device are as follows: comprehensive protection of the reservoir from shock waves, ease of use and the possibility of reuse.

Sources of information
1. Galkin V.V. Gilmanov R.A. Dorogoveiko I.Z. Blasting under water. M. Nedra, 1987, p. 74 93: "Methods for reducing the intensity of the GUV of an underwater explosion" analog. (In Appendix p. 90 of this section, in Fig. 27 there is a bubble curtain of perforated square-shaped pipes in plan.

 2. RF patent N 2027018, E 21 F 5/00, application dated 03.06.92, N 5045902 - prototype.

Claims (1)

 A device for absorbing shock waves containing a screen of freely hanging ropes and cords made of synthetic fibers, characterized in that when conducting blasting operations underwater, it is additionally equipped with a grid placed horizontally above the charge, made of a material with a density lower than the density of water, along the perimeter of which ropes are fixed and cords grouped with a variable density increasing in the direction of passage of the shock waves, and made of a material with a density greater than the density of water.