RU118425U1 - COMBINED BLASTING OF EXPLOSIVES - Google Patents

Abstract

1. Combined damming of an explosive charge, including alternating sections of inert material, characterized in that it contains sections made of pneumatic bellows, which are shells of elastic air-tight fabric material with shut-off valves filled with compressed air under pressure and placed between sections of inert bulk material. ! 2. The stemming according to claim 1, characterized in that a bulk inert material in bulk or packaged form is used as the stemming material. ! 3. The stemming according to claim 1, characterized in that the pneumocylinders have different cross-sectional shapes.

Description

The utility model relates to mining and construction and can be used in the development of rocks in an explosive way using borehole, chamber and other charges of industrial explosives.

Clogging is an essential element of an explosive charge. It prevents energy loss in the process of detonation of explosives, increases the completeness of detonation, increases the duration of the piston action of the explosion products and the duration of the stress state of the rock under the action of an explosion; helps to reduce the amount of toxic gases emitted into the atmosphere in the explosion products; prevents the formation of a shock wave in the air and limits the expansion of pieces of rock.

The sealing action of the stemming during explosion is determined by its size (length and diameter), as well as the resistance of its material to the action of dynamic loads under the pressure of the explosion products. There are a number of designs of locking faces in the form of plastic plugs, wooden and concrete wedges, metal devices (1-8). The complexity and low-tech implementation of such clashes limit their scope.

The so-called active stemming or stemming with locking charges are known, which are one or more small explosive charges located along the inert stemming material at the same distance from each other and exploding simultaneously with the main borehole or chamber explosive charge (9, 10). The disadvantage of such troubles is the need to use additional explosive charges, which complicates its formation and leads to increased danger and an increase in the cost of drilling and blasting.

Known combined stemming, consisting of alternating water-filled ampoules and locking wads (11), adopted by the authors as a prototype. The disadvantage of the prototype clogging is the limited use (only in holes or small diameters wells) due to the complexity of the manufacture and installation of water-filled ampoules of large diameter and large length.

To increase the strength of the stemming and increase its resistance to ejection, it is necessary to divide the stemming in sections of different materials that have high adhesion to the walls of the approach to the charging chamber in the non-explosive-charged part of the charge generation, which will ensure its compaction and lateral spacing with an increase in the holding capacity of the whole jammer due to the forces of friction in the charging output.

To disperse the explosive charge in order to form and fix the air gaps in the borehole explosive charges, limited-sized air cylinders are used (12-15).

The technical task of the utility model is to increase the quality of crushing of the rock mass and reduce the cost of blasting by increasing the locking (sealing) properties of the face, reducing the concentration of harmful substances in the dust and gas cloud, reducing the range of the pieces of rock during an explosion and attenuating the effects of shock-air waves.

The technical problem was solved by the development of the design of a combined stemming, consisting of alternating sections of inert material, which additionally contains sections made of pneumocylinders, which are shells of elastic airtight fabric material with shut-off valves, filled with compressed air under pressure and placed between sections of loose inert material and a portion of the inert material of the combined stemming is made of loose inert material.

After detonation of the explosive charge in the charging chamber, the pressure of the detonation products sharply increases and there is a dynamic impact of gases on the end surface of the stemming section adjacent to the explosive charge. Since the sections are in close contact with each other, a compression shock wave will go along the entire stemming hole. With an increase in the speed of application of the shock load, the inertia mass of the stemming mass increases, which, together with the forces of friction of the stemming unit against the walls of the rock working and the force of internal friction of the materialing uniting, causes a lateral expansion in each section of the stemming unit. In the material of each section of the stemming, a so-called “plug” is formed, which determines the effectiveness of the combined stemming. The shock air wave, propagating through the mine working, interacts with an inert material and pneumocylinders from an elastic airtight fabric material (hereinafter referred to as pneumocylinders) and gradually loses its strength due to their elastic deformation. In areas where pneumatic cylinders are located, the wedging action of the stemming is increased due to the increased lateral expansion of pneumatic cylinders under the action of compressed air pressure on the walls of the charging output. The detonation products are locked in the mine until the rock is completely destroyed. The time of departure of the combined stemming from the charge generation significantly increases in comparison with the same stemming of a homogeneous inert material and exceeds the time during which the expansion of the detonation products of the explosive charge is completed.

The technical effect can only be achieved by combining all the features of a utility model. The spreading of stemming into sections made of an inert bulk material and pneumocylinders of elastic airtight fabric material having a high adhesion of the stemming materials to the walls of the production ensures a longer sealing of gaseous explosion products, which helps to reduce the amount of toxic gases released into the atmosphere in the explosion products; prevents the formation of a shock wave in the air and limits the expansion of pieces of rock.

The essence of the utility model is illustrated in figures 1, 2.

Figure 1 - scheme of the combined stemming of the adit explosive charge (in the context).

Figure 2 is a diagram of the combined stemming of the borehole explosive charge depending on the location of the air cylinders (in the context):

- a) - the overlapped section of the well contains one or more air cylinders mounted on top of each other along the height of the well;

- b) - the overlapped section of the well contains several pneumocylinders installed close to each other.

Designations:

1 - charging chamber;

2 - explosive charge;

3 - underground mining to accommodate the stemming;

4 - section of the stemming of loose inert material (indices 1, 2, 3 indicate the numbers of sections from the explosive charge);

5 - section of the stemming of pneumocylinders from elastic airtight fabric material (indices 1, 2, the numbers of sections from the explosive charge are indicated);

6 - air valve shut-off valve;

7 - well.

Screening and / or small fractions of rock crushing, and / or sand or similar products that have a higher resistance to axial displacement from the action of an air shock are used as an inert bulk material of the sections of the bottomhole. Combined stemming in the form of alternating sections of bulk materials and pneumocylinders increases the blocking effect of explosion products compared to stemming of a uniform inert material.

The proposed combined stemming (Figs. 1, 2) consists of alternating sections 4 of inert bulk material, one of which (4 ¹ ) is adjacent to the explosive charge 2, and sections of pneumocylinders of elastic airtight fabric material 5 with a shut-off valve 6.

The procedure for the formation of combined stemming.

After placing the explosive charge 2 in the explosive chamber 1 (Fig. 1 - adit charge; Fig. 2 - borehole charge), a combined stemming is formed by alternating sections of jamming 4 of a certain length from inert material and sections 5 of a certain length from pneumocylinders.

The inert bulk material of the combined stemming of the adit charge (Fig. 1) is previously poured into the bags, and the section is formed by their orderly packing. After the site of inert bulk material 4 ¹ layerwise placed along or perpendicular to the axis of the production of pneumatic cylinders 5 ¹ with shut-off valves 6, unfilled with compressed air. Then, sections 4 ² , 5 ² are formed in a similar way. The means of initiation are placed in the explosive charge and an explosive network is laid. Then the pneumatic cylinders are filled with compressed air under pressure through a flexible air line with shut-off and overpressure-relieving valves or from an autonomous source of compressed air supply or in any other known manner. The end section 4 ^{3 of the} combined stemming is filled with an inert bulk material over the entire cross section of the blasting to its mouth. The role of stemming in the explosion of chamber charges for ejection and discharge increases with increasing scale of the explosion. This is due to the fact that the process of ejection and discharge of the rock is completed with the full expansion of the explosion products (to atmospheric). In the event of explosion of chamber charges for ejection or discharge, the holding time of the stemming is commensurate with the time of full expansion of the explosion products.

When forming a combined stemming of a borehole or drill hole charge (Fig. 2), pneumatic cylinders 5 ¹ with shut-off valves 6 are installed on a site of inert bulk material 4 ¹ , and filled with compressed air under pressure by any known method. Then a portion of inert material 4 ^{2 is} poured, after which a portion of pneumocylinders 5 ² with a shut-off valve 6 is formed in the manner described above. The number of sites and their sizes - in accordance with the blasting project. The end section 4 ^{3 of the} combined stemming is made of inert bulk material over a full section of a well or a hole.

When filling pneumatic cylinders with compressed air, the effect of “bursting” of pneumatic cylinders in the overlapped section of an underground mine or a well arises and a tight pressure of the pneumatic cylinders to each other and to the working surface along the entire perimeter is ensured. The high boost pressure of the air spring made of elastic, airtight fabric material increases the adhesion forces of the air spring to the production circuit, as well as the forces required to shift the entire combined stemming when exposed to expanding explosion gases. It is advisable to orient the end surfaces of the pneumocylinders of elastic, airtight fabric material towards the shock wave to provide a larger area of contact with the walls of the mine. To ensure a more dense stacking of pneumatic cylinders made of elastic, airtight fabric material in an overlapping section of rock production, pneumatic cylinders can have a round, square, rectangular or triangular cross section depending on the blasting project. The number of pneumocylinders made of elastic, airtight fabric material, the shape and procedure for their installation is determined taking into account the size and shape of the overlapping section.

An example implementation of a utility model (figure 1).

An explosion is carried out to discharge an adit charge weighing 2000 tons from an explosive of granulite RP for the construction of an explosive-filling dam. The length of the horizontal approach mine (adit), free of explosive charge, is 100 m, the cross section is 10 m ² , the volume of excavation to be jammed is 1000 m ³ .

The combined stemming (Fig. 1) consists of three sections of inert material (sand with a density of 1.7 t / m ³ ) 20 m long and two sections of seven pneumocylinders of elastic airtight fabric material 20 m long each.

The proposed combined clogging allows to reduce the time of the clogging up to 20 days with a duration of continuous clogging - 30 days.

The efficiency of the explosion using combined stemming increased by 20-25% due to an increase in the volume of useful dumped rock into the design circuit of the blasting facility.

The claimed technical result - improving the quality of crushing of the rock mass and reducing the cost of blasting - is provided by the construction of the stemming:

- reducing the complexity of the formation of the stemming, lowering the cost and increasing the productivity of the drilling operations due to the design of the combined stemming, consisting of sections of loose inert material and sections of pneumocylinders having a high adhesion of the materials of the stemming with the working walls;

- the reliability of sealing workings of any cross section due to the design of the proposed combined stemming, consisting of sections made of different materials - bulk material and air bags made of elastic airtight fabric material;

- the exclusion of the passage through the stem of the wave of compression and acceleration of the stem due to the dispersion of the bottom hole material into sections of inert material and sections of pneumocylinders from elastic airtight fabric material, which increases its locking properties;

- a decrease in the concentration of harmful substances in the dust and gas cloud and a decrease in its dispersion zone due to longer locking of the detonation products, which ensures the completion of secondary reactions in the explosive chamber.

A production check of the inventive combined stemming showed its trouble-free work on crushing rocks as well charges and chamber charges during the discharge of rocks during the construction of blasting facilities.

Information sources

1. Gogichev I.I. “The effective and optimal length of the hole for boreholes”, Sat. "Explosive business" No. 59/16, M. "Nedra", 1966.

2. RF patent No. 2365872.

3. RF patent No. 2291394.

4. RF patent No. 2301962.

5. RF patent No. 2301963.

6. RF patent №2308674.

7. RF patent No. 2371670.

8. RF patent No. 2390722

9. Seinov N.P., Zharikov I.F., Udachin V.G. “On the effectiveness of active stemming”, collection of articles "Explosive business", No. 71/28, M. "Nedra", 1972.

10. Chernihiv A.A. "The method of flat charge systems in mining and construction", M., "Nedra", 1971.

11. RF patent for utility model No. 83129.

12. RF patent for useful model spruce No. 69630.

13. RF patent No. 2235971.

14. RF patent No. 2379621.

15. RF patent No. 2285895.

Claims (3)

1. The combined jamming of the explosive charge, comprising alternating sections of inert material, characterized in that it contains sections made of air cylinders, which are shells of elastic airtight fabric material with shut-off valves, filled with compressed air under pressure and placed between sections of inert bulk material. 2. Clogging according to claim 1, characterized in that the bulk inert material in bulk or in packaged form is used as the clogging material. 3. The jamming according to claim 1, characterized in that the pneumatic cylinders have a different geometric shape in cross section.