RU2004824C1 - Method for damping air shock waves in blasting operations in mine workings - Google Patents

Description

gene fluid into the soil; a vertical plate 11 is fixed at the end of the platform facing the fixed jumper 1 to rake the bottom of the formed snow mass and seal it; 12-trolley with water; 13-pump; 14 - an electric motor; 15 is a nozzle for dispersing water; 16 - formed snow massif; 17-line for supplying water to the nozzle; 18 - compressor; 19 vortex tube; 20 - a stream of chilled air; 21 - a stream of heated air.

Figs. 3 and 4 show a part of a mine working filled with snow; 22 - plates of solid material (e.g., plywood sheets) placed perpendicular to the longitudinal axis of the mine.

The method is carried out as follows.

A gas-tight jumper 1 is installed in the bottom and a platform 2 is rolled up with a mobile gas-tight jumper 3, setting it 1.5-2 m from the fixed jumper 1.

The bundles of flexible plates 5 and brushes b are pushed all the way into the walls and the bottom of the mine, and at the excavation vault, the plates 5 and brushes 6 are left in the lowered state before cooling the closed space, leaving a gap at the mine vault to exit the mine atmosphere, you - cramped with denser gases - nitrogen during evaporation of liquid nitrogen, or with a stream of cooled air from a vortex tube.

By turning the cryostat 8 in the basket 9 on the hinge 10, the container is tilted and part of the liquid nitrogen is poured onto the soil, working out. When using a vortex tube, the flow of cooled air from the vortex tube (with a temperature of minus 70 ° С) is directed into the bridged zone. The chilled air is supplied from the vortex tube during continuous operation of the compressor without interruptions until the formation of the snow mass is complete, and liquid nitrogen is poured periodically in several stages.

Evaporating nitrogen and air cooled to minus 70 ° C, as denser, fill the barred volume from the bottom up, displacing the mine atmosphere through the gap between the movable bridge 3 and the output shaft. The output of cooled air or evaporated nitrogen is reliably determined visually from the output of the mist generated from the condensed moisture of the mine atmosphere.

After the above, the flexible plates 5 and brushes 6 are extended to be pressed against the arch

generation and supply water, dispersed by its nozzle 15 with the formation of snow.

When filling the bottom hole with evaporating nitrogen or cooled air from a vortex tube, as well as with subsequent snow generation, the arch and walls of the mine are frozen from the surface, which eliminates the water drop from the mine arch and prevents the snow mass from rapidly its contact with the rock.

When the snow mass reaches 2/3 of the height of the development, the platform 2 moves back and forth to press the plate 11 onto the bottom of the snow mass, moving it to the fixed bridge 1 and up. After 2-3 m from the bridge 1, a plywood sheet 22 is installed perpendicular to the grodal axis of the mine (Figs. 3 and 4). At the same distance of 2-3 m, the following plywood sheets are placed in the snow massif.

Continuing to generate snow with continuous supply of air from a vortex tube (at a temperature of -70 ° C) or by periodically pouring liquid nitrogen out of a cryostat, they complete the production of snow with snow, forming a snow mass containing alternating sheets of plywood with a total length of 6-9 m.

0 After completing the filling with snow of the production of the required length, the device for carrying out the method, mounted on a mobile platform, together with a trolley designed to

5 of water are removed from the bottom and blast holes or bore holes are blown up.

The main advantages of the method are: the efficiency of constructing a hedge of snow to extinguish the HVW, the operation is mechanized, in addition to installing plates of plywood; improved working conditions due to cooling workings (which is important for deep horizons); low cost of the materials used — water and liquid technical nitrogen of GOST 9293-74 from 42 to 45 rubles / t — grade lit and I, respectively, ensures the efficiency of the method; there is no need for cleaning and removal of building materials for the construction of lintels destroyed by shock waves - cleaning is limited to removing plywood sheets of 2-3 pcs.) after spontaneous melting of snow; high reliability of fire extinguishing due to the alternation of loose layers

5 snow in the array and sheets of plywood. Plywood sheets prevent loose snow from being ejected in the central part of the snow mass due to the WBW - thanks to the plywood, the WBW spreads over the area

almost the entire cross section of the mine, preventing the ejection of snow along the axial part of the loose snow massif. In addition, the alternation of layers of loose snow and sheets of plywood creates a layered structure of materials of different densities, which contributes to the intense attenuation of the HEM in accordance with the known patterns of wave propagation through layered media.

Claims (2)

The claims  METHOD OF EXTINGUISHING AIR SHOCK WAVES IN EXPLOSION OPERATIONS IN MINING, including installing a jumper, cooling an isolated volume of a mine and creating a barrier to; ways of propagating air shock waves, by filling the cooled volume over the entire cross section of the mine with solid material, characterized in that what with (56) 1. Umnov A.E., Golik A.S., Paleev D.Yu., Shevtsov N.R. Prevention and localization of explosions in underground conditions. - M .: Nedra, 1990.S. 286. with. 261-277. Engineering 5 structures for shock wave damping in mine workings. 2. Copyright certificate of the USSR No. 1163005. class E21 F 5/00. published. 1985. 0 the goal of reducing labor costs, accelerating the creation of the barrier and increasing its effectiveness by combining the barrier  of materials of different densities and structures, snow is used to fill the mine, obtained by freezing dispersed water, and when forming a snow mass, plates of solid material are periodically installed perpendicular to the longitudinal axis of the mine. FIG. 2 22 FIG. 3 FIG. 4