Draining method and water-repellent flower tube of still water on the roof of mine sedimentary sandstone

Abstract

Provided is a method for removing sandstone top plate still water in a mine sedimentary rock extraction zone. Still water in wet soft fine sandstone is unwatered in an intensifying mode through a negative pressure air exhaust water absorption type intensifying unwatering machine according to the negative pressure consolidation theory. The depth H1 of a draining filtering pipe on the negative pressure air exhaust water absorption type intensifying unwatering machine which is inserted into the sandstone is 1 / 3-2 / 3 of the thickness H of the wet soft fine sandstone. A gap between a cylinder wall of the draining filtering pipe and a sandstone water draining hole is sealed in a double mode by an O-shaped sealing ring and a square sealing cushion. The draining filtering pipe used in the negative pressure air exhaust water absorption type intensifying unwatering machine comprises a pipe body and a draining film which is tightly wrapped on the pipe body. One end of the pipe body is provided with an opening, and the other end is sealed. Outer threads are arranged at the opening end of the pipe body, and the sealing end of the pipe body is provided with a taper pushing head. The overall length of draining sections on the cylinder wall of the draining filtering pipe is h which is 1 / 3-2 / 3 of the thickness H of the wet soft fine sandstone, and according to the fluid mechanics theory and the sandstone still water gravitational field distribution law, the three draining sections with different aperture ratios are arranged on the cylinder wall of the pipe body.

Description

technical field [0001] The invention relates to a method for removing still water from a sandstone roof in a mine sedimentary rock mining area and a special water-repellent flower tube for a negative-pressure suction water-absorbing enhanced dehydration machine, which is mainly used for enhanced dehydration of still water on a wet, soft, muddy, fine-grained sandstone roof to make the sandstone Consolidation does not collapse. Background technique [0002] In the sedimentary rock layer of the mine, if the excavation roof is argillaceous cemented fine-grained sandstone, this kind of sandstone is relatively hard in the anhydrous section, and the mining support roof is not easy to collapse; The wet and soft sandstone on the roof collapsed, causing a safety accident. When the water content of the sandstone reaches a certain level, the sandstone will become tofu-like. If the water reaches a critical state in the sandstone, it will form quicksand, which cannot be supported at all....

AI Technical Summary

Problems solved by technology

[0007] But, there are following problems in the negative pressure suction water-absorbing type strengthened dehydration machine during work: the one, when the thickness of wet soft muddy sandstone 2 has been determined, the hydrophobic flower tube 3- that inserts in the wet soft muddy sandstone 2 The length of 1 determines the hydrophobic effect

According to the theory of fluid mechanics and the law of distribution of the static water gravity field of sandstone, the water content of the upper sandstone is low and the water content of the bottom sandstone is high. Therefore, the arrangement of the drainage holes 3-1-2 on the drainage flower tube 3-1 should follow this law, Otherwise, it will affect the drainage efficiency; the third is the sealing problem between the wall of the drainage flower tube 3-1 and the sandstone drainage orifice. If it is not handled properly, it will seriously affect the negative pressure of the enhanced dehumidifier when pumping air and absorbing water, resulting in a decrease in the drainage efficiency

Images