CN111579342B - A gas-bearing sample preparation device for coal and rock experiments - Google Patents

Abstract

The invention discloses a preparation device of a gas-containing sample for coal and rock experiments, which comprises an upper hydraulic cylinder (A1), a forming die (B) and a lower hydraulic cylinder (A2) which are sequentially arranged on a symmetrical upright post (2) from top to bottom; a first die (10) is embedded in the forming die, a second die (9) is embedded in the first die (10), and a third die (7) is embedded in the second die (9); the first compression bar (1) of the upper hydraulic cylinder extends downwards into the upper part of the forming die (B) through the perforation of the upper cover plate (8); the second compression bar (14) of the lower hydraulic oil cylinder upwards extends into the lower part of the forming die (B) through the perforation of the lower cover plate (12), the first compression bar (1) and the second compression bar (14) are coaxially installed, and the side wall of the forming die (B) is provided with an air inlet pipe (11) communicated with an adsorption air source. The invention has the technical effects that: the compression molding of coal rock samples with various sizes and gas-containing states is realized.

Description

A gas-containing sample preparation device for coal and rock experiments

technical field

The invention belongs to the technical field of coal and rock experiments, and in particular relates to a gas-containing sample preparation device for coal and rock experiments.

Background technique

The safe production of coal mines is related to the national energy supply, so it is necessary to carry out basic research on the physical and mechanical properties of coal rocks. When conducting research on a wide range of tectonic coals with different development levels and deformations in my country, it is often difficult to take large samples for cutting and processing because the coal seam is soft, so coal powder or rock powder is usually pressed into blocks to facilitate related work .

At present, the compression methods of coal and rock experimental samples are mainly divided into two types: uniaxial pressing and triaxial pressing. Among them, the uniaxial compression of the coal rock sample is to apply a unidirectional force to the broken coal rock sample to consolidate the sample, but there may be uneven force on the sample during the pressing process, the sample is not easy to take out, and only one size sample can be realized. The preparation will affect the results of subsequent experiments. The triaxial pressing method is to apply pressure from three directions to consolidate the coal rock sample, but the triaxial pressing method is cumbersome to operate, the device is complicated, and it can only realize the sample pressing process of a single size.

The main problems in the existing coal rock sample pressing technology are: 1. The influence of gas in the coal rock forming process is ignored. 2. It is difficult to prepare coal rock experimental samples by uniaxial pressing or triaxial pressing, especially the triaxial pressing method It is difficult to press-form a test sample in the shape of a cuboid.

Contents of the invention

Aiming at the problems existing in the prior art, the technical problem to be solved by the present invention is to provide a gas-containing sample preparation device for coal and rock experiments, which can replace uniaxial or triaxial loading conditions, and realize various sizes and gas-bearing states of coal and rock The compression molding of the sample is convenient and quick.

The technical problem to be solved by the present invention is achieved through such a technical scheme, which includes an upper hydraulic cylinder, a molding die and a lower hydraulic cylinder arranged sequentially from top to bottom, and the upper hydraulic cylinder, forming mold and lower hydraulic cylinder are fixed on at least two on a symmetrical column; the forming mold includes a housing, an upper cover and a lower cover, the housing is fixed in the middle of the column, the upper and lower covers cover the upper and lower sides of the housing, and are sealed with a second sealing ring, the cover The lugs on the edge slide through and fit on the column and are pressed with nuts, the first mold is embedded inside the shell; the second mold is embedded inside the first mold, and the third mold is embedded inside the second mold;

The first pressure rod of the upper hydraulic cylinder extends downwards into the upper part of the forming mold through the perforation of the upper cover plate; the second pressure rod of the lower hydraulic cylinder extends upwards into the lower part of the forming mold through the perforation of the lower cover plate. The lower pressing rod is coaxially installed, and the first sealing ring is arranged in the perforation of the upper cover plate and the lower cover plate; an air inlet pipe is opened on the side wall of the forming mold to communicate with the adsorption gas source.

Compared with the existing coal rock sample preparation device, the present invention has the following technical effects:

Since the forming mold contains a variety of cavities, it can realize the compression molding of loose coal rock samples in a gas-bearing state of various sizes, and can meet the sample preparation function under the loading conditions of uniaxial or triaxial coal rock experiments, ensuring the success of experimental sample preparation rate, and consider the influence of gas on the formation process of coal rock.

Description of drawings

The accompanying drawings of the present invention are as follows:

Fig. 1 is the structural representation of device of the present invention;

Fig. 2 is the perspective view of device of the present invention;

Fig. 3 is the structural representation of molding die;

Figure 4 is a structural schematic diagram of the platen assembly

Fig. 5 is a diagram of the lower oil pipeline equipped with a cross-shaped pipeline.

In the figure, A1, the upper hydraulic cylinder; A2, the lower hydraulic cylinder; 1, the first pressure rod; 2, the column; 3, the connection block; 4, the cylindrical pressure head; A seal ring; 13, nut; 14, the second pressure rod;

B. Forming mold; 7. Third mold; 8. Upper cover plate; 9. Second mold; 10. First mold; 11. Air intake pipe; 12. Lower cover plate; 15. Second sealing ring; 16. Second mold Three briquetting blocks; 17, the second briquetting block; 18, the first briquetting block.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the present invention will be further described:

As shown in Figures 1 and 2, the present invention includes an upper hydraulic cylinder A1, a molding die B and a lower hydraulic cylinder A2 arranged sequentially from top to bottom; the upper hydraulic cylinder A1, the molding die B and the lower hydraulic cylinder A2 are fixed on at least two On the root symmetrical column 2,

The molding die B includes a shell, an upper cover 8 and a lower cover 12, the shell is fixed on the middle section of the column 2, the upper cover 8 and the lower cover 12 are sealed on the upper and lower sides of the shell, and are sealed with a second sealing ring 15 , the lugs on the edge of the cover plate are slid through and sleeved on the column and pressed with nuts, and the first mold 10 is embedded inside the housing; as shown in Figure 3, the second mold 9 is embedded inside the first mold 10, and the second mold 9 A third mold 7 is embedded inside;

The first pressure rod 1 of the upper hydraulic cylinder extends downward through the perforation of the upper cover plate 8 into the upper part of the forming mold B; the second pressure rod 14 of the lower hydraulic cylinder extends upward through the perforation of the lower cover plate 12 into the lower part of the forming mold B. A pressure rod 1 is coaxially installed with the second pressure rod 14, and the first sealing ring 6 is arranged in the perforation of the upper cover plate 8 and the lower cover plate 12; an air inlet pipe 11 is provided on the side wall of the forming mold B to communicate with the adsorption gas source.

The shell of described molding die B is the cylindrical shell of diameter 50cm, high 30cm; As shown in Figure 3, described first mold 10 is the notch cylinder of diameter 40cm, high 25cm; Second mold 9 is long 20cm× A notch cube with a width of 20cm×a height of 25cm; the third mold 7 is molded with two core boards, each core board is 10cm long×width 5cm×height 25cm, and the top surface of each core board has a radius of 2.5cm and a depth of 10cm. Semi-cylindrical groove, the bottom surface of the two core boards has a square groove with a length of 5cm x width 2.5cm x height of 10cm; after the two core boards are molded together, the upper top surface is synthesized into a cylindrical groove with a diameter of 5cm and a height of 10cm; The core boards are turned over and combined to form a square groove with a bottom surface of 5×5cm square and a height of 10cm, suitable for the third platen.

The two core plates of the third mold 7 are turned over to use the square groove mold cavity formed by the combination of the two core plates, which can press a cuboid sample of 5×5×10 cm. The upper hydraulic cylinder A1 is actively pressed with the pressure plate, and the lower hydraulic cylinder A2 is assisted. Fit fixed.

As shown in Figures 1 and 4, the upper hydraulic cylinder A1 is fixed on the top of the column with a nut 13. The first pressure rod 1 of the upper hydraulic cylinder also includes a connecting block 3 and a cylindrical pressure head 4. The first pressure rod 1 is connected to Block 3 is connected with cylindrical indenter 4, and cylindrical indenter 4 passes upper cover plate 8, and upper fuel delivery pipe 5 communicates with the central hole of cylindrical indenter 4, and the central hole of cylindrical indenter 4 bottom surface is connected with lower oil delivery pipe 51.

As shown in FIG. 5 , the lower oil delivery pipe 51 is detachably connected with a cross-shaped pipeline with a length of 8 cm, and the ends of the cross-shaped pipeline are provided with spray holes extending into the inside of the forming mold B. The cross-shaped pipeline is suitable for the mold cavity of 20cm×20cm×20cm. The straight-type lower oil delivery pipe cannot evenly spray lubricating oil on the inner surface of the square forming mold, and the cross-shaped pipeline is more uniform.

As shown in Fig. 4 and Fig. 5, the lower oil delivery pipe 51 connected to the bottom surface of the cylindrical indenter 4 is covered with a pressing plate assembly matched with the molding die, and the pressing plate assembly includes a first pressing plate 18, a second pressing plate 17 and a third pressing plate 16, The inner frame of the first pressing plate 18 nests the second pressing plate 17 , the inner frame of the second pressing plate 17 nests the third pressing plate 16 , and the groove on the top surface of the third pressing plate fits the cylindrical indenter 4 . The pressing plate assembly is not only stacked together, but also can be disassembled and separated. When in use, the pressing plate of the corresponding size is selected to fit the mold cavity of the forming mold B. The three pressing plates cooperate with the three square die cavities of the molding die B, and the cylindrical indenter 4 cooperates with the cylindrical groove after the third mold 7 is closed. The upper hydraulic cylinder A1 provides downward force through the cylindrical pressure head. The cylindrical pressure head fits the pressure plate, and the force is transmitted to the pressure plate of the corresponding size selected below. The pressure plate directly contacts the coal and rock scattered materials, and is pressurized and formed.

Cylindrical indenter 4 bottom surface diameters are 5cm, and the first pressing plate 18 is the square of long 20cm * wide 20cm * high 3cm, and the square groove of opening side length 10cm deep 2mm fits the second pressing plate above the first pressing plate; The second pressing plate 17 is long 10cm ×Width 10cm×Height 3cm square, the square groove of length 5cm and depth 2mm above the second pressing plate fits the third pressing plate; The third pressing plate 16 is a square of length 5cm×Width 5cm×High 3cm, and the opening diameter above the third pressing plate is A perfect circular groove with a depth of 5 cm and a depth of 2 mm fits the cylindrical pressure head; all central openings of the pressure plate can allow the lower oil delivery pipe 51 to pass through.

The lower hydraulic cylinder A2 is fixed on the bottom of the column with a nut 13; the functions of the lower hydraulic cylinder A2 and the second pressure rod 14 are: 1. Only the pressing of the upper hydraulic cylinder A1 will result in a coal sample as large as 20cm×20cm×20cm. Loose, so the lower hydraulic cylinder A2 needs to apply force to each other; 2. After the coal sample is made, the lower hydraulic cylinder A2 needs to be used to push the mold out.

The process of using the above-mentioned device to prepare coal rock test samples is:

Step 1. Select and assemble the supporting molding mold, select the sample of the size required for the experiment to make a mold for assembly, and the third mold has a cylindrical sample with a diameter of 5cm x 10cm in height and a cuboid with a length of 5cm x width 5cm x 10cm in height For the inner cavity of the sample, the first mold has an inner cavity for preparing a cubic coal rock sample with a length of 20 cm wide × 20 cm × a height of 20 cm, and the second mold has an inner cavity for preparing a cubic coal rock sample with a length of 10 cm × width 10 cm × height 25 cm. Cavity;

Step 2. Install the pressure plate assembly, the upper oil delivery pipe and the lower oil delivery pipe, select the corresponding pressure plate of the mold and install it on the bottom surface of the cylindrical indenter, connect the corresponding oil delivery pipe and spray a small amount of oil evenly to the inner wall of the mold;

Step 3. Put the loose coal powder or rock powder required for the experiment into the mold, use the lower oil delivery pipe to stir the material evenly, and remove the lower oil delivery pipe;

Step 4. Fix the upper and lower cover plates with nuts, fill the gas filling hole with adsorption gas to stabilize the pressure to 1MPa and stabilize it for 30min.

Step 5. Use the upper and lower hydraulic cylinders to pressurize both sides of the upper and lower platens, so that the coal rock sample is formed by constant pressure pressing or displacement control pressing according to the experimental requirements.

Step 6: Release the pressure of the gas, open the upper side cover, and use the lower hydraulic cylinder to push the sample out of the mold to complete the sampling and the preparation of the gas-containing sample.

Claims (3)

1. A gas-containing sample preparation device for coal and rock experiments, characterized in that it includes an upper hydraulic cylinder (A1), a forming mold (B) and a lower hydraulic cylinder (A2) arranged in sequence from top to bottom; the upper hydraulic cylinder ( A1), the molding die (B) and the lower hydraulic cylinder (A2) are fixed on at least two symmetrical columns (2); The molding die (B) includes a shell, an upper cover (8) and a lower cover (12), the shell is fixed on the middle section of the column (2), and the upper cover (8) and the lower cover (12) are sealed on the shell The upper and lower sides of the body are sealed with the second sealing ring (15). The lugs on the edge of the cover slide through the vertical column (2) and are pressed tightly with nuts. The first mold (10) is embedded inside the housing. The first mold (10) A second mold (9) is embedded inside, and a third mold (7) is embedded inside the second mold (9); The first pressure rod (1) of the upper hydraulic cylinder extends downward through the perforation of the upper cover plate (8) into the upper part of the forming mold (B); the second pressure rod (14) of the lower hydraulic cylinder passes upward through the lower cover plate (12) The perforation extends into the lower part of the molding die (B), the first pressure rod (1) and the second pressure rod (14) are coaxially installed, and the first seal is set in the perforation of the upper cover plate (8) and the lower cover plate (12). circle (6); the side wall of the forming mold (B) has an air intake pipe (11) connected to the adsorption gas source; The shell of the forming mold (B) is a cylinder; the first mold (10) is a notched cylinder, the second mold (9) is a notched cube, and the third mold (7) is molded with two core plates, There is a semi-cylindrical groove on the top surface of each core board, and a square groove on the bottom surface of the two core boards. After the two core boards are molded together, the upper top surface forms a cylindrical groove, and the two core boards are turned over to form a square groove cavity. The upper hydraulic cylinder is actively pressed with the pressure plate, and the lower hydraulic cylinder is assisted and fixed; The first pressure rod (1) of the upper hydraulic cylinder also includes a connecting block (3) and a cylindrical pressure head (4). The first pressure rod (1) is connected to the cylindrical pressure head (4) through the connecting block (3). The indenter (4) passes through the upper cover (8), the upper oil delivery pipe (5) is connected to the center hole of the cylindrical indenter (4), and the lower oil delivery pipe (51) is connected to the center hole of the bottom surface of the cylindrical indenter (4); The lower oil delivery pipe (51) is detachably connected with a cross-shaped pipeline, and the ends of the cross-shaped pipeline are provided with spray holes extending into the inside of the forming mold (B); The lower oil delivery pipe (51) connected to the bottom surface of the cylindrical indenter (4) is sheathed with a pressure plate assembly matched with the molding die. The pressure plate assembly includes a first pressure plate (18), a second pressure plate (17) and a third pressure plate (16) , the inner frame of the first pressing plate (18) nests the second pressing plate (17), the inner frame of the second pressing plate (17) nests the third pressing plate (16), the groove on the top surface of the third pressing plate fits the cylindrical indenter (4), The three pressing plates cooperate with the three square die cavities of the molding die B, and the cylindrical indenter (4) cooperates with the cylindrical groove of the third mold (7) after mold closing. 2. The gas-containing sample preparation device for coal and rock experiments according to claim 1, characterized in that: the shell of the forming mold (B) is a cylinder with a diameter of 50 cm and a height of 30 cm; the first mold (10 ) is a notched cylinder with a diameter of 40cm and a height of 25cm, the second mold (9) is a notched cube with a length of 20cm×width 20cm×a height of 25cm, and the third mold (7) is molded with two core plates, each core plate Length 10cm×width 5cm×height 25cm, each core board has a semi-cylindrical groove with a radius of 2.5cm and a depth of 10cm on the top surface, and a square groove with a length of 5cm×width 2.5cm×height 10cm on the bottom of the two core boards. After the two core boards are molded, the upper top surface is synthesized into a cylindrical groove with a bottom diameter of 5cm and a height of 10cm, and the two core boards are turned over to form a square groove with a bottom surface of 5×5cm square and a height of 10cm. 3. The gas-containing sample preparation device for coal and rock experiments according to claim 1, characterized in that: the diameter of the bottom surface of the cylindrical indenter (4) is 5 cm, and the first pressing plate (18) is 20 cm long x 20 cm wide x 3 cm high Square, the top of the first pressing plate (18) is provided with a square groove with a side length of 10 cm and a depth of 2 mm to fit the second pressing plate; the second pressing plate (17) is a square of 10 cm in length × 10 cm in width × 3 cm in height, and the second pressing plate (17) is provided with A square groove with a side length of 5cm and a depth of 2mm fits the third platen; the third platen (16) is a square with a length of 5cm×width 5cm×a height of 3cm, and a square groove with a diameter of 5cm and a depth of 2mm is opened above the third platen (16) fit the cylindrical pressure head (4); all pressure plate center openings can allow the lower oil delivery pipe (51) to pass through.