A device for preventing explosives from scattering upward in blastholes

Abstract

The present invention relates to a device for preventing explosives from scattering upward through blastholes. The device comprises a flexible strip and an elastic capsule. The flexible strip is made of plastic or rubber, including PP, PET, PLA, and PVC. The elastic capsule comprises a packaging bag and an internally encased elastomer. This technical solution blocks upward blastholes by leveraging the elasticity difference between the elastic material in its natural state and the blasthole, and utilizes the elastic material's volume compressibility to enable loading of the elastic capsule. The operating principle and process are simple, making it easy to promote and apply.

Description

Technical Field

[0001] The invention relates to a device, in particular to a device for preventing explosives from scattering upward into a blasthole, and belongs to the technical field of structural devices. Background Art

[0002] Drilling and blasting is a method of mining rock through drilling, charging, and blasting, and is currently the primary means of excavating and crushing rock masses. Drilling and blasting is particularly predominant in mining operations, as it is highly adaptable to rock formation geological conditions, offers low excavation costs, and is particularly suitable for the excavation and crushing of hard rock. Large-scale mining operations such as the pillarless sublevel caving method and the staged rock drilling chamber method in underground mines often utilize upward blasting. The charging process often uses a pneumatic charge loader to blow powdered explosives into the blasthole. The high-pressure air compacts the explosives to a certain density. However, after charging, as the charging tube is withdrawn, the high-pressure air supply ceases, and the powdered explosive falls from the blasthole under the action of gravity, resulting in wasted explosives. At mining sites, waste newspapers, paper packaging, or explosive bags are often used to simply block upward blastholes to prevent explosives from falling. However, since the blocking process is performed after the charge tube is withdrawn, the process is not tightly connected, which can easily cause a large amount of explosives to fall during the blocking process. Furthermore, this blocking method provides limited resistance and is not suitable for blocking large-diameter blastholes. Therefore, a new solution is urgently needed to solve these technical problems. Summary of the Invention

[0003] The present invention is aimed at the problems existing in the prior art and provides a device for preventing explosives from scattering upward into the blasthole. This technical solution achieves the blocking of the upward blasthole through the elastic difference between the elastic material in its natural state and the blasthole, and achieves the filling of the elastic capsule with the help of the volume compressibility of the elastic material. The operating principle and process are simple and easy to promote and apply.

[0004] In order to achieve the above-mentioned object, the technical solution of the present invention is as follows: a device for preventing explosives from scattering upward in a blasthole, characterized in that the device comprises a flexible strip and an elastic capsule;

[0005] The flexible strip is made of plastic or rubber, and the materials include but are not limited to PP, PET, PLA and PVC materials.

[0006] The elastic capsule comprises a packaging bag and an elastic body wrapped inside.

[0007] The length of the flexible strip is about 4 cm greater than the circumference of the explosive charging tube, the width is 2-4 cm, and the thickness is 2-4 mm;

[0008] Two conical protrusions are axially symmetrically arranged on the flexible strip. Both cones are located at the center axis of the flexible strip in the length direction, with a diameter of 8-10 mm, a height greater than the thickness of the charge tube, and a spacing of half the circumference of the charge tube.

[0009] Two circular through holes are axially symmetrically arranged on the flexible strip. Both through holes are located at the center axis of the length direction of the flexible strip, with a diameter of 4-8 mm. The spacing between the through holes is equal to the circumference of the charging tube.

[0010] The packaging bag material includes but is not limited to one or a mixture of polyethylene, polypropylene, polyvinyl chloride, and vinyl acetate.

[0011] When the packaging bag is filled with gas, the shape is an ellipsoid, the major axis is 10 cm, the minor axis is less than or equal to the diameter of the charging tube, the thickness is 5-10 threads, and the opening is located at one side of the major axis end.

[0012] The elastomeric material includes but is not limited to one of polyurethane (memory foam), natural or artificial sponge.

[0013] Before compression, the elastomeric material is cylindrical with a height of 15-20 cm and a diameter 3-5 cm larger than the diameter of the blast hole. The elastomer can be put into a packaging bag by being squeezed by external force. The squeezing method includes manual pressure or vacuum pressure. During packaging, the height direction of the elastomer is kept parallel to the long axis direction of the packaging bag. After packaging is completed, it is sealed with a cable tie or nylon rope to obtain an ellipsoidal elastic capsule.

[0014] A method for preventing explosives from scattering upward in blastholes using the device comprises the following steps:

[0015] (1) Drill two symmetrical through holes on the charge tube at a distance of 2-4 cm from the tube mouth. The through holes have a diameter of 8-10 mm. Select a flexible strip of appropriate size according to the diameter of the charge tube.

[0016] (2) Tie the flexible strip to the charge tube 2-4 cm away from the tube mouth, align the two conical protrusions with the reserved through holes on the charge tube, and then pass the bolts through the two through holes of the flexible strip and tighten them;

[0017] (3) Design the length and diameter of the elastic material according to the bore diameter and charge amount, squeeze it into a pre-prepared packaging bag, and finally tie it tightly with a cable tie or nylon rope to prepare an ellipsoidal elastic capsule with a long axis of about 10 cm and a short axis smaller than the inner diameter of the charge tube;

[0018] (4) After connecting the detonator to the explosive transmission device, place it at the bottom of the blasthole, and use high-pressure air to blow the explosives into the blasthole through the charging tube and maintain a certain density of explosives;

[0019] (5) After the charge is completed, the elastic capsule is placed in the charge tube, and the capsule is blown into the blast hole using high-pressure air and wedged into the explosive. When the capsule passes through the end of the charge tube, it is scratched by the conical hard protrusion and expands back to a cylindrical shape in a short time. Since the diameter of the cylinder is larger than the diameter of the blast hole, the difference in tube diameter and the friction resistance of the material surface itself can prevent the explosive from sliding down into the hole.

[0020] (6) After the charging is completed, the charging tube is pulled out from the blast hole and the above process is repeated to charge the next blast hole.

[0021] Compared with the prior art, the present invention has the following advantages: (1) The present invention achieves the sealing of the upward blasthole by the elastic difference between the elastic material in the natural state and the blasthole, and realizes the filling of the elastic capsule by means of the volume compressibility of the elastic material. The operation principle and process are simple and easy to promote and apply. (2) The present invention uses the original wind pressure during the charging process to transport and fill the elastic capsule, which simplifies the construction process; at the same time, the strong wind pressure can wedge the elastic capsule into the explosive, eliminating the self-stabilizing structure of the elastic capsule in the blasthole and saving materials. (3) The elastic capsule described in the present invention is soft and insulating, and the expansion process is a physical process. After the expansion takes effect in the blasthole, it can effectively prevent the explosive from sliding without affecting the normal operation of various explosive transmission equipment, and has high safety. (4) All components of the present invention do not contain metal materials, which ensures safety during use and does not affect the subsequent processing of ore (especially metal ore). In addition, the flexible strip has a simple structure, long service life, is reusable, and is economical and convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the main view of the flexible strip when it is unfolded;

[0023] Figure 2 It is a side view of the flexible strip when it is unfolded;

[0024] Figure 3 is a longitudinal cross-sectional view of the elastic capsule;

[0025] Figure 4 is a cross-sectional view of the elastic capsule;

[0026] Figure 5 It is a schematic diagram of the structure, installation and use of the device of the present invention;

[0027] Figure 6 Schematic diagram of the process of the elastic capsule passing through the drug-loading tube;

[0028] Figure 7 Schematic diagram of the process of wedging the elastic capsule into the explosive;

[0029] Figure 8 Schematic diagram of the elastic capsule fully expanded in the explosive;

[0030] Figure 9 This is a longitudinal view of the opening at the front end of the charge tube;

[0031] Figure 10 This is a cross-sectional view of the opening at the front end of the charge tube;

[0032] Figure 11 This is a cross-sectional view of the flexible strip installed on the charge tube.

[0033] Among them: 1-flexible strip, 2-conical protrusion, 3-flexible strip through hole; 4-blast hole; 5-explosive; 6-charging tube; 7-elastic material; 8-packaging bag; 9-cable tie or nylon rope; 10-charging tube through hole; 11-elastic capsule in compressed state; 12-elastic capsule not fully expanded; 13-fully expanded elastic capsule; 14-high-pressure air; 15-bolt connection. DETAILED DESCRIPTION

[0034] In order to deepen the understanding of the present invention, this embodiment is described in detail below with reference to the accompanying drawings.

[0035] The embodiments and comparative examples are based on the underground medium-deep hole blasting experiment of a mine. The outer diameter of the charging tube used in the mine is 30 mm, the wall thickness is 2 mm, the blast hole diameter is 60 mm, the length is 8 m, the charging length is 5 m, the air pressure of the pneumatic charging device is 0.5 MPa, and the charging density is 0.95 g / cm 3 The detonation method is bottom hole detonation, and the explosive used is powdered ammonium nitrate explosive.

[0036] Example 1

[0037] like Figure 9 、 10 As shown, two through holes 10 with a diameter of 8 mm are symmetrically drilled at a position 2 cm away from the end of the charging tube 6.

[0038] like Figure 1 、 2 As shown in Figures 11 and 12, the flexible strip 1 is injection-molded from PP, with a total length of 13.5 cm, a width of 2 cm, and a thickness of 2 mm. The conical protrusions 2 are 8 mm in diameter, 4 mm in height, and spaced 4.7 cm apart. The flexible strip through-holes 3 are 4 mm in diameter and spaced 9.5 cm apart. Align the two conical protrusions 2 with the reserved through-holes 10 on the charge tube, then insert bolts 15 through the two through-holes 3 of the flexible strip and tighten.

[0039] like Figure 3 、 4 As shown, the elastic material 7 is made of polyurethane, with a diameter of 9 cm and a height of 15 cm before compression. It is placed in a packaging bag 8 with a long axis of 10 cm and a short axis of 28 mm, and is sealed with a cable tie 9 to form a compressed elastic capsule 11.

[0040] The explosive 5 is blown into the blast hole 4 through the charging tube 6 by high pressure air 14 and the density of the explosive is kept at 0.95 g / cm 3 ;

[0041] like Figure 5 As shown, after the charging is completed, the elastic capsule 11 in the compressed state is installed in the charging tube 6 from the tail end of the charging tube.

[0042] like Figure 6 、 7 As shown in FIG8 , high-pressure air 14 is used to blow the compressed elastic capsule 11 out of the charge tube 6 . The packaging bag 8 is then ruptured by the conical protrusion 2 and continues to move forward. The ruptured packaging bag 8 forms an incompletely expanded elastic capsule 12 , which is wedged into the explosive 5 . Within a short period of time, a fully expanded elastic capsule 13 is formed. At this point, the capsule's own elastic force and friction completely block the blasthole, preventing powder from falling. The charge tube can then be withdrawn, completing the charge.

[0043] Example 2

[0044] like Figure 9 、 10 As shown, two through holes 10 with a diameter of 9 mm are symmetrically drilled at a position 3 cm away from the end of the charging tube 6.

[0045] like Figure 1 、 2 As shown in Figures 11 and 11, the flexible strip 1 is injection-molded from PET, with a total length of 14 cm, a width of 3 cm, and a thickness of 3 mm. The conical protrusions 2 have a diameter of 9 mm, a height of 4 mm, and a spacing of 4.7 cm. The flexible strip through-holes 3 have a diameter of 4 mm and a spacing of 9.5 cm. Align the two conical protrusions 2 with the reserved through-holes 10 in the charge tube, then insert bolts 15 through the two through-holes 3 of the flexible strip and tighten.

[0046] like Figure 3 、 4 As shown, the elastic material 7 is made of polyurethane, with a diameter of 10 cm and a height of 17.5 cm before compression. It is placed in a packaging bag 8 with a long axis of 10 cm and a short axis of 28 mm, and sealed with a cable tie 9 to form a compressed elastic capsule 11.

[0047] The explosive 5 is blown into the blast hole 4 through the charging tube 6 by high pressure air 14 and the density of the explosive is kept at 0.95 g / cm 3 ;

[0048] like Figure 5 As shown, after the charging is completed, the elastic capsule 11 in the compressed state is installed in the charging tube 6 from the tail end of the charging tube.

[0049] like Figure 6 、7 As shown in FIG8 , high-pressure air 14 is used to blow the compressed elastic capsule 11 out of the charge tube 6 . The packaging bag 8 is then ruptured by the conical protrusion 2 and continues to move forward. The ruptured packaging bag 8 forms an incompletely expanded elastic capsule 12 , which is wedged into the explosive 5 . Within a short period of time, a fully expanded elastic capsule 13 is formed. At this point, the capsule's own elastic force and friction completely block the blasthole, preventing powder from falling. The charge tube can then be withdrawn, completing the charge.

[0050] Example 3

[0051] like Figure 9 、 10 As shown, two through holes 10 with a diameter of 10 mm are symmetrically drilled at a position 4 cm away from the end of the charging tube 6.

[0052] like Figure 1 、 2 As shown in Figures 11 and 11, the flexible strip 1 is 3D-printed from PLA, with a total length of 13 cm, a width of 4 cm, and a thickness of 4 mm. The conical protrusions 2 have a diameter of 10 mm, a height of 4 mm, and a spacing of 4.7 cm. The flexible strip through-holes 3 have a diameter of 4 mm and a spacing of 9.5 cm. Align the two conical protrusions 2 with the reserved through-holes 10 on the charge tube, then insert bolts 15 through the two through-holes 3 of the flexible strip and tighten.

[0053] like Figure 3 、 4 As shown, the elastic material 7 is made of polyurethane, with a diameter of 11 cm and a height of 20 cm before compression. It is placed in a packaging bag 8 with a long axis of 10 cm and a short axis of 28 mm, and is sealed with a cable tie 9 to form a compressed elastic capsule 11.

[0054] The explosive 5 is blown into the blast hole 4 through the charging tube 6 by high pressure air 14 and the density of the explosive is kept at 0.95 g / cm 3 ;

[0055] like Figure 5 As shown, after the charging is completed, the elastic capsule 11 in the compressed state is installed in the charging tube 6 from the tail end of the charging tube.

[0056] like Figure 6 、 7 As shown in FIG8 , high-pressure air 14 is used to blow the compressed elastic capsule 11 out of the charge tube 6 . The packaging bag 8 is then ruptured by the conical protrusion 2 and continues to move forward. The ruptured packaging bag 8 forms an incompletely expanded elastic capsule 12 , which is wedged into the explosive 5 . Within a short period of time, a fully expanded elastic capsule 13 is formed. At this point, the capsule's own elastic force and friction completely block the blasthole, preventing powder from falling. The charge tube can then be withdrawn, completing the charge.

[0057] Comparative Example 1

[0058] After using the pneumatic charging device to normally charge the upward blast hole, use newspapers and explosive bags to simply seal the blast hole.

[0059] The scattered explosives in the above embodiments and comparative examples were weighed, and the results showed that the amount of explosives dropped from the upward blastholes in the embodiments was less than 200 g, while the amount of explosives dropped from the upward blastholes in the comparative example was about 5 kg.

[0060] It should be noted that the above embodiments are not intended to limit the scope of protection of the present invention, and equivalent changes or substitutions made on the basis of the above technical solutions fall within the scope of protection of the claims of the present invention.

Claims

1. A device for preventing explosives from scattering upward into a blasthole, characterized in that: The device comprises a flexible strip and an elastic capsule; The flexible strip is made of plastic or rubber, The elastic capsule comprises a packaging bag and an elastic body wrapped inside; The length of the flexible strip is 4 cm greater than the circumference of the explosive charging tube, the width is 2-4 cm, and the thickness is 2-4 mm; Two conical protrusions are arranged axially symmetrically on the flexible strip, both located at the center axis of the length direction of the flexible strip, with a diameter of 8-10 mm, a height greater than the thickness of the charge tube, and a spacing equal to half the circumference of the charge tube. Two circular through holes are arranged axially symmetrically on the flexible strip, both located at the center axis of the length direction of the flexible strip, with a diameter of 4-8 mm, and a spacing equal to the circumference of the charge tube. The packaging bag material includes one or a mixture of polyethylene, polypropylene, polyvinyl chloride, and vinyl acetate; When the packaging bag is filled with gas, it is in the shape of an ellipsoid, with a major axis of 10 cm, a minor axis less than or equal to the diameter of the charging tube, a thickness of 5-10 wires, and an opening located on one side of the major axis end; The material of the elastic body includes one of polyurethane, natural or artificial sponge; Before compression, the elastomer is cylindrical with a height of 15-20 cm and a diameter 3-5 cm larger than the diameter of the blast hole. The elastomer can be squeezed into a packaging bag by external force. The squeezing method includes manual pressure or vacuum pressure. During packaging, the height direction of the elastomer is kept parallel to the long axis direction of the packaging bag. After packaging, a cable tie or nylon rope is used to seal the bag to obtain an ellipsoidal elastic capsule; the flexible strip is tied to the charging tube at a position 2-4 cm away from the tube mouth; and the elastic capsule is placed in the charging tube.

2. A method for preventing explosives from scattering upward in a blasthole using the device according to claim 1, characterized in that: The method comprises the following steps: (1) Drill two symmetrical through holes on the charge tube at a distance of 2-4 cm from the tube mouth. The diameter of the through holes is 8-10 mm. According to the diameter of the charge tube, select a flexible strip of appropriate size; (2) Tie the flexible strip to the charge tube at a distance of 2-4 cm from the tube mouth, align the two conical protrusions with the reserved through holes on the charge tube, and then pass the bolts through the two through holes of the flexible strip and tighten them; (3) Design the length and diameter of the elastomer according to the borehole diameter and charge amount, squeeze it into a pre-prepared packaging bag, and finally tie it tightly with a cable tie or nylon rope to prepare an ellipsoidal elastic capsule with a long axis of about 10 cm and a short axis smaller than the inner diameter of the charge tube; (4) After connecting the detonator to the explosive transmission device, place it at the bottom of the blasthole. Use high-pressure air to blow the explosive into the blasthole through the charging tube and maintain a certain density of explosives. (5) After the charge is completed, the elastic capsule is placed in the charge tube. The capsule is blown into the blast hole using high-pressure air and wedged into the explosive. When the capsule passes through the end of the charge tube, it is scratched by the conical hard protrusion and expands back to a cylindrical shape in a short time. Since the diameter of the cylinder is larger than the diameter of the blast hole, the explosive can be prevented from sliding down into the hole by relying on the tube diameter difference and the friction resistance of the material surface itself. (6) After the charging is completed, the charging tube is pulled out from the blast hole and the above process is repeated to charge the next blast hole.

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