RU2804470C1 - Sleeve of asymmetric design for loading rising wells with an emulsion explosive materials - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: sleeve of asymmetric design for loading rising wells with an emulsion explosive materials (EEM) is a waterproof and sealed tubular shell at one end with an outer diameter greater than the diameter of the loaded well, while the shell is made with transverse stitching at an angle to its longitudinal axis at regular intervals to form pockets under filling their EEM. Each transverse stitching has an inclined section and a longitudinal stitching section extending from it to form a side passage for the charging device hose on one side of the shell between the shell wall and the longitudinal stitching. At the angle of inclination of the inclined sections of the transverse stitching from 30° up to 45° the height of the opening between the pockets adjacent to the height of the sleeve for introducing EEM with a charging device hose with a diameter of 0.1 m is from 0.4 m to 0.6 m, the distance between the inclined sections of the transverse stitching along the outer side of the shell is from 1.1 m to 1 .5 m, the distance between the extreme point of the inclined section of the transverse stitching of one pocket on the outer side of the shell and the extreme point on the line of the inclined section of the transverse stitching from the side of the longitudinal stitching of the adjacent pocket is from 0.6 m to 1.0 m.

EFFECT: achievement of uniform rock crushing with a 10-15% reduced consumption of EEM due to the formation of a detonation-capable charge when filling the sleeve of EEM.

1 cl, 6 dwg

Description

The invention relates to the mining industry and can be used in blasting rocks of any degree of water content and fracturing in underground workings with single and fan-shaped loading of rising wells with water-emulsion (and water-gel) explosives (EWE).

The use of fabric hoses when creating downhole emulsion explosive charges has found quite widespread use in mining practice (RU 2104473, Togunov M.B. “Increasing the efficiency of blasting rocks with emulsion explosives” / M.B. Togunov, S.V. Semkin // V book: Development of resource-saving technologies in blasting - Ekaterinburg: IGD Ural Branch of the Russian Academy of Sciences, 2009). The main advantages of using hoses indicate a reduction in the cost of a blast hole due to a decrease in the specific consumption of explosives, a lower environmental load on the environment and a more uniform crushing of the blasted rock mass (Prokopenko B.S. Physical and technical basis for the destruction of rocks by explosions of borehole charges of explosives in hoses: Dissertation ... Doctor of Technical Sciences / 05.15.11 / Prokopenko Viktor Stepanovich - Kiev - 2002). In this case, a characteristic feature of these hoses is the fact that they have a diameter smaller than the diameter of the well being charged. This circumstance prevents the use of this technology to create an explosive charge in upward wells.

In connection with the expansion of the scope of application of explosives to underground mining, solving the problem of developing technologies for loading upward wells with these explosives is of great importance. To solve this problem, various authors propose to use hoses of special designs (RU 154388, RU 154389, RU 170984, Maslov I.Yu. “Industrial emulsion explosives and initiation systems in blasting” / I.Yu. Maslov, V.I. Sivenkov , S.V. Ilyakhin, etc. - M.: VNIIgeosystem. - 2018). However, the proposed design solutions do not contain methods for calculating the parameters of these hoses, which complicates their use in practice and causes excessive consumption of explosives.

Thus, a hose for loading a well with an explosive is known, containing a waterproof and sealed at one end tubular shell for placing a hose from the charging device inside it, while the shell is made of fabric with hydrophobic impregnation by stitching the side sections of the fabric along its length, the diameter of the shell is larger diameter of the well being charged, the sealed end of the shell is the upper end of the shell, inserted into the ascending well, the shell is made gas-permeable with transverse stitching at an angle to its longitudinal axis at equal intervals of at least four shell diameters and leaving a side passage for the charging device hose with one the side of the shell between the shell wall and the firmware (RU 154388, F42D 1/10, publ. 08/20/2015).

This solution was adopted as a prototype.

In the known solution, the sleeve is made with transverse stitching at equal intervals along the length of the sleeve, leaving a side passage along one wall for the charging hose. Transverse stitching of the sleeve is carried out in a section at an angle to its longitudinal axis (from 30 to 45°), which ends with stitching in the form of a section along the axis of the sleeve. The side passage for the charger hose is made on one side of the sleeve between the wall of the sleeve and the stitching. The design of the sleeve is simple and technologically advanced.

Despite the simplicity of the design and the convenience of loading the well, the issue of holding the hose in the well due to the frictional forces of the hose material with the rock and the issue of quantitatively filling the hose with explosives remain unresolved. In practice, both of these issues are solved by overfilling the emulsion explosive sleeve, in which the hose expands and rests against the wall of the well, but in this case there is an overconsumption of emulsifier, since its volume is not used to obtain the explosion energy optimized in terms of parameters for crushing rock, but to expand the sleeve.

When the hose is overfilled, the emulsion explosive is subjected to chemical gassing (a chemical reaction of the emulsion with the gas-generating additive occurs slowly) and the “hose-emulsion explosive” system needs to expand somewhere. If this does not happen, but there is a continuous charge of emulsifier, the system will not be able to expand - visible gas bubbles will not form (the gaseous substance released during the chemical reaction will simply dissolve in the liquid emulsifier at increased pressure) - the density of the emulsion explosive will not decrease - sensitivity to the detonation pulse will not appears - there is a failure of detonation of the borehole charge.

This drawback does not allow for uniform crushing of the rock due to the accelerated process of releasing explosive energy.

The present invention is aimed at achieving a technical result, which consists in achieving uniform crushing of rock with a 10-15% reduction in the consumption of emulsifying explosives due to the formation of a detonation-capable charge when filling the emulsifier sleeve.

This technical result is achieved by the fact that in a sleeve of an asymmetrical design for loading rising wells with an emulsion explosive, containing a waterproof and sealed at one end tubular shell with an outer diameter greater than the diameter of the well being charged, while the shell is made with transverse piercing at an angle to its longitudinal axis through equal intervals for the formation of pockets for filling them with explosives, while each transverse stitching has an inclined section and a section of longitudinal stitching extending from it to form a side passage for the charger hose on one side of the shell between the shell wall and the longitudinal stitchings, at the angle of inclination of the inclined sections transverse stitching from 30° to 45°, the height of the opening between pockets adjacent to the sleeve height for inserting explosives using a charger hose with a diameter of 0.1 m is from 0.4 m to 0.6 m, the distance between the inclined sections of the transverse stitching on the outer side of the shell equals from 1.1 m to 1.5 m, the distance between the extreme point of the inclined section of the transverse stitching of one pocket on the outer side of the shell and the extreme point on the line of the inclined section of the transverse stitching from the side of the longitudinal stitching of the adjacent pocket is equal to from 0.6 m to 1 .0 m.

These features are essential and are interrelated to form a stable set of essential features sufficient to obtain the required technical result.

The present invention is illustrated by a specific example of execution, which, however, is not the only possible one, but clearly demonstrates the possibility of achieving the required technical result.

In fig. 1 general view of the sleeve design, longitudinal section;

fig. 2 diagram for calculating the design parameters of the hose;

fig. 3 - diagram of a hose with an installed intermediate detonator and a hose before filling with explosives;

fig. 4 - filling the upper pocket of the EVV sleeve with a hose from the charger to form an air cavity in this pocket;

fig. 5 - filling the explosive explosive located under the upper pocket with a hose from the charger;

fig. 6 - demonstration of air cavities in pockets after filling them with explosives.

According to the present invention, the design of a sleeve for loading explosive explosives when used in a raise well is considered.

In general, the hose for emulsion explosives (Fig. 1) is a waterproof gas-permeable shell 1 with a sealed upper end 2 for placing inside the hose 3 (Fig. 3) from the charger (not shown), which supplies industrial emulsion explosives to the shell. The shell is made of woven or non-woven fabric with hydrophobic impregnation by stitching the side sections 4 of the fabric along its length in the direction of the sleeve diameter greater than the diameter of the well being charged. The diameter D of the sleeve is larger than the diameter of the well being charged. The shell is made with transverse piercings 5 at an angle to its longitudinal axis at equal intervals of at least four shell diameters and leaving a side passage for the charger hose on one side of the shell between its wall and the piercings. And on the side of the open lower end of the shell is equipped with a valve to seal the shell filled with explosives when removing the hose from the charger.

In this case, each transverse stitching 5 has an inclined section 6 (at an angle β of inclination of sections of the transverse stitching from 30° to 45°), and a longitudinal section 7 of the transverse stitching extending from it, which is used to form a side passage 8 for the hose 3 of the charger with one on the side of the shell between the shell wall and the longitudinal sections there are 7 piercings.

Thus, the specified firmware forms pockets along the length of the sleeve, located at an equal distance from each other to ensure uniform and approximately equal filling of the cavities of the pockets with explosives when the hose moves at a constant speed along the side passage 8.

A feature of the claimed hose is that the height of the opening c between pockets adjacent to the height of the hose for inserting explosives with the hose 3 of the charger (made with a diameter of 0.1 m) is from 0.4 m to 0.6 m, the distance b between the inclined sections of the transverse stitching on the outer side of the shell is from 1.1 m to 1.5 m, the distance between the extreme point of the inclined section of the transverse stitching of one pocket on the outer side of the shell and the extreme point on the line of the inclined section of the transverse stitching from the side of the longitudinal stitching of the adjacent pocket is from 0 .6 m to 1.0 m (Fig. 2).

With this design of the sleeve, the opening for introducing explosives is located above the extreme point of the inclined section on the outer side of the shell. When loading explosive explosives into pockets, hose 3 (Fig. 3) slowly descends along the shell at a given speed. When passing through the opening area, the explosive agent fills the pocket until the moment when the hose outlet pipe becomes lower than the extreme point of the longitudinal section of the piercing of the pocket that is being filled with the explosive explosive at the moment. This leads to the formation of an air cavity in the pocket (Fig. 3).

The presence of an air cavity unfilled with emulsion explosive is important, since the emulsion explosive is subjected to chemical gassing (slowly, a chemical reaction of the emulsion with a gas-generating additive occurs) and the system needs to expand somewhere. When gases are released, the pressure in the air cavity increases, but the chemical composition of the emulsion explosive itself does not change (the gaseous substance released during the chemical reaction does not dissolve in the liquid phase of the emulsifier at elevated pressure).

On the other hand, air cavities in a borehole charge reduce the initial explosion pressure and explosion energy density per unit charge surface, but at the same time lengthen the time of exposure of the explosion to the destroyed medium and thus reduce the local (blasting) effect of the explosion, leading to over-grinding of the medium in the near zone explosion. This contributes to greater uniformity and stability of the results of crushing significant volumes of the medium (Leshchinsky A.V., Shevkun E.N. “Dispersal of borehole charges” Khabarovsk, Tomsk State University Publishing House, 2009, p. 16).

With regard to the air cavities in the pockets, it should be clarified that this makes it possible to organize voids without interrupting the continuity of charge extension along the length of the well. This is not a radial void, but asymmetrical narrowing along the length of the charge (Marchenko L.N. Explosion energy and charge design. - M.: Nauka. - 1965, p. 13). This makes it possible to reduce the mass of explosives in the formed charge by 10-15%. According to Marchenko, detonation activation of explosives in pockets ensures crushing of rock no worse (but more uniform) compared to a solid core charge.

The device is used as follows.

First, an intermediate detonator 9 (ID) is placed into the ascending well on a waveguide or detonating cord 10 (up to the design mark for installing the intermediate detonator in the well; the intermediate detonator is equipped with an independent fixation device in the well).

Or, as shown in FIG. 3, the PD is installed in the upper open “pocket” of the sleeve, after which the neck of the sleeve is collected “into a forelock” and tied with braid (attached to the end of the sleeve). In this case, there is no need to use an independent device for fixing PD in the well. And the PD installed in this way is in direct contact with the explosive explosive - which increases the reliability of the initiation of the explosive explosive: the detonation pulse from the PD is transmitted to the explosive, bypassing possible obstacles in the form of air cavities that may form when installing the PD.

The sleeve is put on the charging hose 3 (Fig. 3) and fed up the well to its bottom. When putting on, the sleeve can be pressed into an accordion for ease of insertion into the well. When placed in a well, the hose can remain partially in the accordion, or it can straighten partially or completely along the entire length (height) of the well. Since the firmware has a unidirectional position, when assembling “in an accordion” the sleeve is assembled on the hose along one common side. When the accordion is inserted into the well, the folds fall off and do not catch on the well wall.

The charger is turned on and the explosive 11 is fed into the sleeve through hose 3. At the initial moment, the end of the hose is located in the side passage at the level of the access opening to the cavity 9 of the first pocket, limited by the firmware and the upper end of the sleeve. Under pressure, explosives pass through the opening and fill the cavity of the first (upper) pocket. When the first pocket is filled, the air leaves it through the pores of the sleeve fabric and in the side seam, the explosive remains inside the sleeve shell 1. At the same time, a void remains in the pocket.

The sleeve, which is larger relative to the diameter of the well, expands and is held by friction forces in the well. In all cases of device design, the diameter of the hose must be greater than the diameter of the well being charged. In this case, due to the imperfection of the inner surface of the well (cracks in the rock mass, falls out of individual parts during drilling), the sleeve filled with explosives expands and is retained in the well due to frictional forces in the contact of the “well wall - sleeve material” pair. In this case, the hose will be supported with friction on the well wall not over the entire surface of the hose, but in areas of pockets filled with explosives. This expansion, as experiments have shown, at the level of the filled part of the pockets, appears when the inclined section of the firmware is located at an angle from 30° to 45°.

This method of holding a hose with an ascending well is based on calculated data in relation to Fig. 2 and confirmed experimentally. The designations of the geometric parameters a, b, c, d, D and β are clear from Fig. 2. In this case, the following relationships must be satisfied between the specified parameters:

B ₀ A ₁ +A ₁ B ₁ =b ⇒ because B ₀ A ₁ =C; A ₁ B ₁ =b-c

D ₁ C ₁ =b= a +C ₁ B ₁ cosβ

b= a +C ₁ B ₁ cosβ= a +Dctgβ

Δ+c+ a =b

Δ=b- а -с=( а +Dctgβ)- а -с=Dctgβ-с

Δ>0 (Dctgβ>c)

Δ<0 (Dctgβ<0)

The value D is assigned based on the condition that the fabric “covers” the sleeve of the charging hose in order to reduce the volume of emulsion explosives leaking out of the “cell” when it is filled.

The value d is assigned based on the conditions of both the free passage of the charging hose and the reduction of difficulties when placing the hose in the well, and can be determined by the formula

The volume V ₀ of the well space, limited by the planes limited by the inclined sections of adjacent pockets, is equal to

where R is the well radius;

The volume V of the explosive enclosed in the sleeve between the inclined sections of adjacent pockets is equal to

The filling factor of the EVV well is equal to

For charges with an air gap, the coefficient of reduction in the actual length of the charge compared to a continuous charge is equal (Marchenko L.N. “Explosion energy and charge design” M., Nauka, 1965)

where ƒ _crepe is the rock strength coefficient according to M.M. Protodyakonov.

The hose design under consideration will make it possible to achieve efficient use of explosion energy at N=K _air .

In accordance with (5) and (6), we determine the condition for the effective use of the hose from the point of view of using the explosion energy of the explosive charge for crushing

However, the most important task of the hose in our case is to create conditions for retaining the charge in the ascending well. It is a priori clear that if each “cell” of the sleeve remains motionless after filling it with explosives, then the entire charge placed in the sleeve will not fall out of the well.

Let's consider the “cell” of the sleeve after filling it with explosives to the level x=Dctgβ (Fig. 2, item 6).

The remaining unfilled part of the “cell” compensates for the subsequent expansion of the explosive due to its gasification, which usually occurs 20-30 minutes after charging. The left space, taking into account (4), creates an initial porosity α of the explosive charge in the “cell” equal to

Where - the initial volume of the unfilled part of the “cell”.

Let us determine the equilibrium conditions for this “cell” of the hose under the influence of the weight of the explosive, the friction forces between the hose and the charging hose extending from the “cell,” and the friction forces holding the “cell” between the casing and the well wall.

The weight of the emulsion explosive at the considered degree of filling of the “cell” is equal to

where ρ is the initial density of emulsifier, kg/m ³ ; g - free fall acceleration, m/s ² .

The total friction force acting on the “cell” is equal to the difference between the friction force of the sleeve on the walls of the well, which holds the “cell”, and the friction force between the sleeve and the charging hose, which contributes to the “cell” falling out of the well, is:

With c>Dctgβ

with с≤Dctgβ

where x is the current coordinate along the generatrix of the “cell”, m (Fig. 1); k _tr , ƒ _tr are the friction coefficients in the “hose-rock” pair and in the “hose-charging hose” pair, respectively. At the same time, we believe that the condition for the formation of a “cell” is fulfilled: c<b-2d.

Condition for immobility of a “cell” in a well:

Based on (10)-(12), taking into account (3), we find a limitation on the friction coefficient in the “hose material-rock” pair, under which the ascending charge does not fall out of the well:

with c>Dctgβ

with с≤Dctgβ

Analysis of the presented dependencies shows that when using hoses of the prototype design, placed in 100 mm wells, for breaking rocks in a wide range of rock strengths, their geometric parameters should be in the range: 0.6 m ≤ a ≤ 1.0 m, 1. 1 m≤b≤1.5 m, 0.4 m≤c≤0.6 m, D≅0.19 m, d≅0.1 m and 20°≤β≤45°. In this case, a porosity of emulsifier after gasification that is favorable for detonation is achieved (10-20%) and retention of the hose in the well when it is partially filled (with air cavities).

Next, the hose is lowered to the opening of the underlying pocket, and the operation of filling it is repeated by analogy with filling the explosives of the first pocket. And so on until the last pocket. As each underlying pocket is filled, an air cavity is formed in it.

The charging hose is removed from the well being charged at a uniform speed equal to the rate of formation of the column of rising borehole explosive charge.

The following additional effects are possible:

- gas inclusions, which will inevitably form during the formation of a rising charge inside the sleeve, will contribute to the occurrence of changes in the detonation speed of the explosive explosive along the length of the charge and, accordingly, the formation of pressure pulsations in the explosion products due to a change in the cross-sectional area of the explosive explosive charge (a large area is in a continuous part of the charge, a smaller one - in the presence of a gas inclusion) - the effect of changing the detonation speed of an explosive charge on the diameter of the explosive charge is known (L.V. Dubnov, N.S. Bakharevich, A.I. Romanov “Industrial Explosives”, M., “ Subsoil", 1988, p. 87). Pressure pulsations in the explosion products enhance the crushing effect of the explosion due to repeated cyclic loading (A. Gorinov et al., “On the practical value of some designs of borehole charges of explosives,” Mining Information and Analytical Bulletin (scientific and technical journal). Selected articles ( special issue) - 2015. - No. 01, M., publishing house "Mountain Book", p. 4].

The present invention is industrially applicable and can be manufactured using existing sewing equipment. The invention makes it possible to place explosive explosives into an ascending well in a differentiated algorithm for distributing explosives along the height of the sleeve. This leads to the detonation of explosive explosives in pockets with a slow increase in gas pressure, which allows the rock to be crushed already at the moment of explosion. At the same time, it became possible to reduce the amount of explosives spent on charging one well.

Claims (1)

A hose of asymmetrical design for loading rising wells with an emulsion explosive (EME), containing a waterproof and sealed at one end tubular shell with an outer diameter larger than the diameter of the well being charged, while the shell is made with transverse stitching at an angle to its longitudinal axis at regular intervals to form pockets for filling them with explosives, each transverse piercing has an inclined section and a section of longitudinal piercing extending from it to form a side passage for the charger hose on one side of the shell between the shell wall and the longitudinal piercings, characterized in that at the angle of inclination of the inclined sections of the transverse piercings from 30° to 45°, the height of the opening between pockets adjacent to the sleeve height for inserting explosives using a charger hose with a diameter of 0.1 m is from 0.4 m to 0.6 m, the distance between the inclined sections of the transverse piercings on the outer side of the shell is equal to from 1.1 m to 1.5 m, the distance between the extreme point of the inclined section of the transverse stitching of one pocket on the outer side of the shell and the extreme point on the line of the inclined section of the transverse stitching from the side of the longitudinal stitching of the adjacent pocket is from 0.6 m to 1, 0 m.