Coal and mash gas extrusion mold

Abstract

The invention relates to a coal and gas extruding mould. The center of a base plate is provided with a charging hole; a charging hole is provided with a gas inlet nozzle; the middle part of a front end plate is provided with a positioning hole; and the positioning hole is provided with an extruding port. The inside of a mould box is provided with a rear pressure plate and three upper pressure plates, wherein the rear pressure plate is fixed on the front end of a rear pressure head; the rear end of the rear pressure head runs through the rear end plate and is fixedly connected with a shim plate; three upper pressure plates are sequentially arranged from front to back and are fixed on the lower end of one upper pressure head respectively; the connecting lines between axes of three upper pressure heads are positioned in the same beeline; and the upper end of the upper pressure head runs through an upper sealing plate and protrudes upwards to the outside of the mould box. The coal and gasextruding mould adopts a mode of combining pressure in the horizontal direction and pressure in the vertical direction, can apply any ladder-type load on a protrudent coal body, has obvious gradient of force applied on a protrudent coal sample, can stimulate the phenomenon of concentrated stress in front of a protrudent working face and stimulate field horizontal ground stress; and a result obtained from a test is accurate and reliable.

Description

technical field [0001] The invention relates to an outburst test device for coal and rock containing gas, in particular to a mold for outburst tests of coal and gas. Background technique [0002] Although the comprehensive effect hypothesis is generally accepted in the field of coal and gas outburst mechanism research, the hypothesis believes that coal and gas outburst is the result of the combined effects of in-situ stress, gas pressure and coal mechanical properties, but the respective roles of the three factors in the outburst process The mechanism is still unclear. In order to further explain the action mechanism of the three factors in the comprehensive action hypothesis, scholars at home and abroad have successively developed a series of coal and gas outburst simulation test devices. [0003] In foreign countries, the former Soviet Union carried out one-dimensional outburst simulation experiments and developed corresponding test devices in the 1950s. The tests showed ...

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Problems solved by technology

[0006] 1. The sizes of outburst coal samples used are all small, and the air intake sources are all "point inflation", which cannot simulate the local stress concentration in front of the working face, and stress concentration is often an important factor causing outburst;

[0007] 2. The protruding mouth of the protruding box is fixed, and a protruding box cannot carry out protruding simulation tests with different protruding calibers;

[0008] 3. The opening method of the outburst is manual, and the opening speed is slow, which affects the time and intensity of coal and gas outburst to a certain extent, and is different from the real underground coal and gas outburst;

[0010] 1. Although the test bench has multiple sets of hydraulic jack devices for applying stepped loads, the loads of multiple sets of hydraulic jacks are all applied to a steel plate (upper platen), and the steel plate is not easily deformed, resulting in a force gradient applied to the protruding coal sample. Not obvious enough;

[0011] 2. The stress applied to the protruding coal sample used in the test is only vertical stress, which cannot simulate the horizontal ground stress existing in the actual situation on site, and the test results are inaccurate;

[0012] 3. Use an upper cover plate to seal the entire protruding box with a large "O" ring. During forming, it is impossible to ensure that the forming pressure applied by the jack is completely loaded on the coal body. The steel plate around the body bears

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