Blocking device for open pit coal mine sampling drilling

Abstract

The utility model discloses a blocking device for open pit coal mine sampling drilling, and belongs to the technical field of coal mining. Under the condition that hole cleaning treatment and grouting treatment are not needed, the device can be rapidly installed in a drill hole, air is effectively prevented from entering the drill hole, and spontaneous combustion of a coal seam is prevented. The blocking device comprises a mandrel, blocking units fixedly installed at the two ends of the mandrel and a flame retardant fixedly arranged between the two blocking units. The blocking unit comprises a conical expansion plug and an inner conical reaming plug fixedly arranged outside the conical expansion plug in a sleeving mode. The water-soluble shell is filled with the flame retardant, and the water-soluble shell is fixedly connected with the mandrel. The coal seam spontaneous combustion prevention device can effectively prevent coal seam spontaneous combustion caused by external factors such as air and water in a drill hole, and has the advantages of simple structure, convenience in use, low cost and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of hole plugging after a sampling drill hole is used, belonging to the technical field of coal mining. Background Art

[0002] Open-pit coal mines refer to coal mines mined on the surface or in shallow layers underground. They have the advantages of low mining cost, high output, and high recovery rate, and are one of the main coal production methods in my country. However, open-pit coal mines also have some problems, such as environmental pollution, land destruction, and safety hazards. Among them, one of the most serious problems is spontaneous combustion of coal seams.

[0003] Spontaneous combustion of coal seams refers to the phenomenon that under certain conditions, coal seams react with air to produce a large amount of heat, causing the temperature of the coal seams to rise to or exceed their own auto-ignition point, thus causing their own natural ignition. Spontaneous combustion of coal seams can cause huge economic losses and safety accidents, such as fires, explosions, and toxic gas leaks. Therefore, preventing and controlling spontaneous combustion of coal seams in open-pit coal mines is an important issue.

[0004] At present, for sampling drilling in open-pit coal mines, two methods are usually used: hole cleaning and grouting. Hole cleaning refers to the use of water or other liquids to clean the mud in the borehole after the drilling is completed, and then the borehole is sealed with a plastic bag or other material. Grouting refers to the use of cement or other materials to fill the voids in the borehole tightly after the drilling is completed. Although these two methods can prevent air from entering the borehole to a certain extent and prevent the spontaneous combustion of coal seams, they also have some disadvantages and shortcomings. For example, hole cleaning requires the consumption of a large amount of water or other liquids, which increases costs and pollution; grouting requires the consumption of a large amount of cement or other materials, which increases costs and solid waste; and neither of these two methods can completely prevent air from entering the borehole, and there is still a certain risk of spontaneous combustion.

[0005] Therefore, it is necessary to develop a new method for plugging sampling boreholes in open-pit coal mines to improve the plugging effect and prevention effect and reduce costs and pollution. Utility Model Content

[0006] In view of the above problems, the utility model proposes a plugging device for sampling boreholes in open-pit coal mines, which can be quickly installed into the borehole without the need for hole cleaning and grouting, and effectively prevents air from entering the borehole, thereby preventing spontaneous combustion of coal seams.

[0007] The technical solution of the utility model is as follows: the blocking device comprises a core shaft 4, blocking units fixedly mounted at both ends of the core shaft 4, and a flame retardant 3 fixedly arranged between the two blocking units;

[0008] The plugging unit comprises a conical expansion plug 1 and an inner conical expansion plug 2 fixedly mounted on the outside of the conical expansion plug 1, wherein the conical expansion plug 1 is a conical water-expandable plug; the flame retardant 3 is filled in a water-soluble shell, and the water-soluble shell is fixedly connected to a core shaft 4.

[0009] Furthermore, the tapered expansion plug 1 is in a cone or truncated cone shape, and its outer diameter gradually increases from the side where the center of the core shaft 4 is located.

[0010] Furthermore, the outer wall of the inner conical reaming plug 2 is matched with the sampling borehole clearance, and the inner wall of the inner conical reaming plug 2 is adapted to the conical expansion plug 1 .

[0011] Furthermore, a receiving groove adapted to the tapered expansion plug 1 is provided on the end surface of the inner tapered reaming plug 2 facing away from the center of the core shaft 4 , and the tapered expansion plug 1 is arranged in the receiving groove and is fixedly connected to the inner tapered reaming plug 2 .

[0012] Furthermore, the expansion rate of the conical expansion plug 1 is 50% to 800%.

[0013] The utility model can effectively prevent the air, water and other external factors in the borehole from causing the coal seam to spontaneously combust, and has the advantages of simple structure, convenient use and low cost.

[0014] A key point of the utility model is the conical expansion plug, which is a hollow conical plug made of water-swellable material. It can expand when encountering mud or reinjected drilling fluid in the borehole, squeezing the external inner conical reaming plug to expand, so that the outer diameter of the reaming plug is larger than the inner diameter of the borehole, tightly clamping the borehole to achieve a blocking effect.

[0015] Another key point of the utility model is the flame retardant, which is a substance that can prevent air from entering the borehole and prevent spontaneous combustion of coal seams. It is located in the cavity in the middle of the plug and can be wrapped and fixed on the core shaft with a water-soluble shell of water-soluble material. When the plug is installed into the borehole, the water-soluble material dissolves and releases the flame retardant. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the structural diagram of this case.

[0017] Figure 2 It is the reference diagram of the usage status of this case;

[0018] In the figure, 1 is a conical expansion plug, 2 is an inner conical expansion plug, 3 is a flame retardant, and 4 is a core shaft. DETAILED DESCRIPTION

[0019] In order to clearly illustrate the technical features of this patent, this patent is elaborated in detail below through a specific implementation method and in combination with its accompanying drawings.

[0020] like Figure 1 , 2 As shown, this case includes:

[0021] Conical expansion plug 1: It is a hollow conical plug made of water-swellable material, which can be connected to the core shaft 4 by threading. Its function is to expand when it encounters water after the plug is installed in the borehole, and to expand the inner conical expansion plug 2 wrapped in the outer layer, so as to block water and air, and prevent rainwater and air from entering the hole and causing spontaneous combustion of the coal seam. In this embodiment, the water-swellable material can be bentonite, highly absorbent resin or water-swellable rubber, etc.

[0022] Inner conical expansion plug 2: This is a hollow inner conical plug made of a material with a certain strength and fire resistance. It can be connected to the core shaft 4 by threading. Its inner diameter is slightly larger than the outer diameter of the conical expansion plug 1. Its function is to deform together with the conical expansion plug 1 after it expands in water, be stretched open, and increase its volume, thereby achieving the purpose of expanding the hole. The outer diameter of the expansion plug should be smaller than the inner diameter of the drilled hole. In this embodiment, the material with a certain strength and fire resistance can be selected from rubber, plastic, steel or other suitable materials.

[0023] Flame retardant 3: This is a substance that can prevent air from entering the borehole and prevent the coal seam from spontaneously igniting. It is located in the cavity in the middle of the plug and can be wrapped and fixed on the core shaft 4 with a water-soluble shell made of a water-soluble material. When the plug is installed in the borehole, the water-soluble material dissolves and releases the flame retardant. In this embodiment, the flame retardant can be aluminum sulfate, ferrous sulfate, magnesium sulfate or other suitable substances.

[0024] Mandrel 4: This is a metal rod made of a high-strength, fire-resistant material, which is used to connect the tapered expansion plug 1, the inner tapered expansion plug 2, and the flame retardant 3. In this embodiment, the high-strength, fire-resistant material can be steel or other suitable materials.

[0025] The utility model provides a method for using the above-mentioned plugging device for sampling and drilling in open-pit coal mines, comprising the following steps:

[0026] The plug is assembled in the laboratory, and then after the drilling is completed, the plug is directly installed into the borehole to a certain depth without the need for hole cleaning. In this embodiment, the length of the plug can be adjusted according to the depth and diameter of the borehole, generally 0.5 to 1 meter, and the installation depth is generally 0.1 to 0.2 meters.

[0027] The conical expansion plug in the lower plugging unit encounters the mud in the hole, absorbs water and expands, squeezing the 2 inner conical expansion plugs outside to expand, causing the outer diameter of the expansion plug to be larger than the inner diameter of the borehole, tightly clamping the borehole to achieve a plugging effect. In this embodiment, the expansion rate of the conical expansion plug 1 can be adjusted according to the diameter of the borehole and the water content of the mud, generally 50% to 800%.

[0028] The upper plugging unit can be refilled with drilling fluid to expand the conical expansion plug 1. In this embodiment, the refilled drilling fluid can be water or other suitable liquids.

[0029] The flame retardant 3 in the cavity will be released due to the dissolution of the water-soluble material wrapped outside, and fill the cavity. In this embodiment, the water-soluble material can be starch, gelatin or other suitable materials.

[0030] There are many specific implementation ways of the present invention. The above is only the preferred implementation mode of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention. These improvements should also be regarded as the protection scope of the present invention.

Claims

1. A plugging device for sampling boreholes in open-pit coal mines, characterized in that: The blocking device comprises a core shaft (4), blocking units fixedly mounted on both ends of the core shaft (4), and a flame retardant (3) fixedly arranged between the two blocking units; The plugging unit comprises a conical expansion plug (1) and an inner conical expansion plug (2) fixedly mounted on the outside of the conical expansion plug (1), wherein the conical expansion plug (1) is a conical water-expandable plug; the flame retardant (3) is filled in a water-soluble shell, and the water-soluble shell is fixedly connected to a core shaft (4).

2. A plugging device for sampling boreholes in open-pit coal mines according to claim 1, characterized in that: The conical expansion plug (1) is in the shape of a cone or a truncated cone, and its outer diameter gradually increases from the side where the center of the core shaft (4) is located.

3. The plugging device for sampling boreholes in open-pit coal mines according to claim 1, characterized in that: The outer wall of the inner conical reaming plug (2) is matched with the clearance of the sampling borehole, and the inner wall of the inner conical reaming plug (2) is matched with the conical expansion plug (1).

4. The plugging device for sampling boreholes in open-pit coal mines according to claim 1, characterized in that: The end surface of the inner conical expansion plug (2) facing away from the center of the core shaft (4) is provided with a receiving groove adapted to the conical expansion plug (1); the conical expansion plug (1) is arranged in the receiving groove and is fixedly connected to the inner conical expansion plug (2).

5. A plugging device for sampling boreholes in open-pit coal mines according to any one of claims 1 to 4, characterized in that: The expansion rate of the conical expansion plug (1) is 50% to 800%.

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