Hole-sealing device and method for flexible self-expanding gas extraction borehole

Abstract

The invention discloses a hole-sealing device and method for a flexible self-expanding gas extraction borehole suitable for an underground coal mine. Front and back sections of flexible plugs are fixed in a fixing groove in a gas extraction pipe. Premix pipes with non-return valves are pre-embedded into the two plugs. The non-return valves at inlets of the premix pipes are connected with tee joints. During the process of sealing the borehole, material bags loaded with A and B components are connected to the tee joints. By extruding the material bags, double-component material is automaticallyand uniformly mixed when flowing through the premix pipes. Then, the material enters the flexible plugs. After the double-component material at the pre-determined amount fills the front and back sections of flexible plugs, the gas extraction pipe and the flexible plugs are quickly conveyed to pre-determined positions of the borehole. Expansion and condensation are performed during the waiting period in order to form a grouting enclosed space. The device is simple in structure, low in weight and small in size and is highly practical because there is no need to carry a high-pressure pump or a water tank to complete hole sealing of gas extraction.

Description

technical field [0001] The invention relates to a gas drainage drilling and sealing device and method, in particular to a flexible self-expanding gas drainage drilling and sealing device and method for underground coal mine pre-extraction. Background technique [0002] Coal seam gas drainage is an effective means of mine gas prevention and utilization, and the sealing of drainage boreholes determines the effect of gas drainage. At present, gas drainage boreholes mostly adopt the form of "two plugs and one injection", that is, two plugs are installed in the front and back of the gas drainage pipe in the drainage borehole, and a closed space is artificially created between the two plugs, and then through The grouting pipe reserved in this confined space is injected with high-pressure grout by an external grouting pump to achieve the effect of drilling seal. For the two plugs of this sealing method, the two materials of two-component polyurethane, that is, isocyanate and combi...

AI Technical Summary

Problems solved by technology

Later, polyurethane foam bags were used to fix the front and rear ends of the gas drainage pipe respectively. These methods are a step forward compared with the use of cement and cement mixture, etc., but still have the following defects: first, the two-component The materials are all artificially poured or mixed by manual kneading. The randomness is too strong, and it is difficult to achieve accurate proportioning and full mixing.

Not only greatly affects the plugging effect, but also causes a lot of waste of materials

Second, the foaming expansion of the two-component material is not restricted, and it will extend along the axial direction of the borehole, which cannot achieve an ideal sealing and sealing effect, resulting in grout leakage during grouting in the middle section, affecting the sealing effect

Third, it is impossible to achieve deep sealing

And this kind of sealing method can't achieve deep sealing anyway.

The main reasons for the above-mentioned defects are that the two types of polyurethane materials cannot be fully mixed, and the second is that there is a lack of means to deliver the materials to the operating position.

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