34results about How to "Shorten prepumping time" patented technology

The invention relates to a coal seam pre-splitting method based on gas extraction, which adopts a 'CO2 gas extraction device' as a tool to blast and pre-split a pre-mined coal seam, so as to increase the crack of the coal seam, drive out gas absorbed on the coal seam and extract the gas. The method particularly comprises the following steps: drilling a hole on the working surface of a pre-mined coal seam, filling CO2 gas extraction device into the drilled hole, sealing the drilled hole, detonating the CO2 gas extraction device, releasing high-pressure CO2 gas for deep-hole impact and pre-splitting of the coal seam, taking out the CO2 gas extraction device, and connecting the drilled hole with a gas extraction system to extract gas. The pre-splitting method of the invention can greatly enhance the permeability of the coal seam, promote the gas dissociation in the coal seam, and improve the underground gas extraction efficiency of the coal mine.

The invention relates to a directional hydraulic pressing penetration, permeability increase and outburst elimination method of a guide groove, which comprises the steps of (1) constructing a guide groove drill or the guide groove drill and control drills in a coal seam; (2) forming a guide groove in the guide groove drill in advance; (3) utilizing the guide groove drill or the control drills to perform hydraulic fractures, utilizing the guide groove and the control drills to perform directional control on the hydraulic fractures, enabling the coal body between the guide groove drill or the guide groove drill and the control drills to be pressed into penetration, forming multiple fractures among drills, and enabling a large amount of nickings to be brought out through the high-pressure water; and (4) after the fractures finish, enabling all the drills to be sealed and accessed into a drainage system, and beginning extraction. By means of the method, the number of pressing penetration of drills can be increased by 50%, the pressure relief scope of the coal seam is increased by over one time, the permeability of the coal seam is remarkably improved, gas extraction is increased by more than four times, measure drills can be reduced by about 60%, fore-pumping time is effectively reduced, area outburst elimination is achieved, and gas hazards can be reduced to the largest extent.

The invention relates to a coal mine underground high-power electric knock assisted hydraulic fracturing permeability enhancement method suitable for increasing extraction radius and total extraction amount of gas extraction drilling. The method comprises the following steps that: a borehole extends from one side of a laneway to a coal seam is constructed; a high-voltage pulse discharger which is installed at the front end of a fracturing steel pipe is sent to the bottom of the borehole; a hole packer, which is separated from the orifice of the borehole by 2 to 3m, is installed on the borehole; the outer end of the fracturing steel pipe is connected with a high-pressure pump station through a high-pressure rubber hose; and the high-voltage pulse discharger is connected with a high-voltage electric pulse generator through a cable; after water with a certain pressure is injected into the borehole, the high-voltage electric pulse generator is started so as to apply high-power electric knock assisted hydraulic fracturing to the coal seam; after the high-power electric knock assisted hydraulic fracturing, the high-voltage pulse discharger and the fracturing steel pipe are quitted; and a gas extraction pipeline is connected into the borehole. According to the method of the invention, high energy released by high-voltage electric pulses is utilized to form shock waves in the water, and therefore, a large number of cracks can be formed in the coal seam, and primary cracks are extended. With the method adopted, the permeability coefficient of a coal body can be increased by 100 to 300 times, and single-hole gas extraction efficiency can be effectively improved.

The invention provides a slotting and fracturing cooperation networking permeability increasing method for a low-permeability coal seam, which is applicable to regional gas control for high-gas-content low-permeability coal seams. The permeability increasing method comprises the following steps that: firstly, hole positions of slotting drill holes and fracturing drill holes are arranged alternately at a floor suction roadway in a networking arrangement mode; each slotting drill hole is subjected to high-pressure water jet flow slotting to form an annular slotted hole; and then, each fracturing drill hole is subjected to segmented fracturing, and a fracture net is formed in the coal seam. The slotting drill holes and the fracturing drill holes are in cooperative arrangement; the slotted holes formed by slotting are used for controlling the expanding direction of fracturing cracks; the number of cracks in the coal seam can be effectively increased through segmented fracturing multiple times; and good conditions are created for the drill hole gas extraction and the gas flowing in the coal seam. After the fracturing cracks are communicated with the slotted holes, a crack network is formed in the coal seam; the permeability coefficient of a coal body around the drill holes can be improved by 150 to 400 times; the single-drill-hole gas extraction effective influence range can be expanded by 2 to 4 times; the drill hole gas extraction quantity can be increased by 3 to 6 times; and the gas pre-extraction time in the high-gas outburst coal seam can be effectively shortened.

The invention provides a gas control method for a large-mining-height working face of a high gas coal seam, and belongs to the technical field of safety of mines. The gas control method comprises the steps of arranging a first bed extraction tunnel during excavating at the working face; upwards arranging a crossing hole through the first bed extraction tunnel to pre-extract gas; arranging and cutting holes in the bed extraction tunnel to pre-extract gas; arranging an inclined connection roadway to form a ventilation circuit; arranging a second bed extraction tunnel and a connection roadway; pre-extracting gas through the crossing hole which is upwards arranged through the first bed extraction tunnel; arranging a high extraction tunnel to reach a gob caving slit band; arranging the crossing hole in the high extraction tunnel; pumping gas at the high extraction tunnel. According to the gas control method for the large-mining-height working face of the high gas coal seam, gas pumping drilling holes are arranged in each tunnel, a gas treatment scheme under the combination of the bed extraction tunnel, the high extraction tunnel and the current coal seam extraction is created, and therefore, the gas emission rate in the excavating and recovery periods at the working face can be effectively reduced, the continuing speed of recovery at the working face is raised, the gas accumulated at the working face and upper corners and ultralimit of gas can be effectively avoided, and as a result, the safety in production at the working face can be ensured.

The invention relates to a liquid carbon dioxide bomb and a propping agent blasting anti-reflection method and a device. The device comprises a liquid storage tube provided with a priming device and liquid carbon dioxide. A releasing tube with propping agent inside is arranged in the front part of the liquid storage tube. A plurality of spray-holes are disposed on the tube wall of the releasing tube. The propping agent is wrapped in a thin strip-shape with plastic film and put into the releasing tube. High-pressure gases produced by vaporized liquid CO2 after liquid CO2 bomb detonates in coal seam form a large number of fractures in drill holes. The high-pressure gas destroys the plastic film wrapping the propping agent during an explosion process. The propping agent with the high-pressure gases enters into coal seam fractures and fractures formed by propping, prolongs existing time of the fractures. The fractures have big presplit radius in coal seam, which can effectively reduce drilling hole amounts in a current extraction and exploitation system in underground coal mines, improve extraction efficiency, reduce pre-extraction time of gas and extraction cost of gas in coal mine, improve a production efficiency of coal, and enhance security of coal production.

A vacuum storing and testing device for transmission electron microscope sample rods belongs to the field of transmission electron microscope vacuum fittings. In storage of the sample rods, energizing testing and heating testing can be performed on the sample rods. The device comprises the components of a movable frame, a vacuum pump system, a vacuum measuring-and-displaying system, a vacuum cap, a valve system, a sample rod storing assembly and a plug. The device realizes simultaneous storage of multiple sample rods and is provided with an adding window which is reserved. The device can pump the air pressure in a chamber from atmosphere pressure to 4*10<-4> Pa within five minutes, and a limit vacuum pressure can reach 5*10<-5> Pa. The vacuum storing and testing device has advantages of effectively preventing electron microscope pollution caused by pollution or erosion by the sample rods in placement at outside, greatly reducing pre-pumping time of the sample rods in the electron microscope, realizing higher speed in reaching a stable vacuum degree of the electron microscope and prolonging service life of the sample rods. The vacuum storing and testing device further realizes benefits of convenient operation, high vacuum degree, easy adding of sample rod storing stations, and high suitability for different types of transmission electron microscope sample rods.

The invention provides a positive pressure and negative pressure combined gas drainage process by pressurizing a coal body of a thick coal seam. The process comprises the following steps of: 1) arranging and drilling holes: selecting drilling distances, array pitches, angles, hole diameters and hole lengths according to the occurrence situation and the drainage radius of a coal seam to be subjected to drainage; 2) carrying out drilling construction and sealing holes: determining angles and directions of a drilling machine to carry out the drilling construction to keep the stability of the drilling machine in a construction period; and sealing the holes after the drilling is finished; 3) injecting water into the coal body and pressurizing: pressurizing the water and injecting into the coal body to fill cracks in the coal body; and 4) carrying out gas drainage: carrying out the gas drainage after carrying out the drilling construction, sealing the holes and stabilizing, and injecting the water into the coal body and pressurizing. With the adoption of the process disclosed by the invention, the gas drainage effect is greatly improved, and the pre-drainage time of gas is greatly shortened, so that the exploiting time of coal is correspondingly increased; and meanwhile, the drainage efficiency is high, the gas concentration in an air flow in a production period is low, an over-limit alarming phenomenon is avoided, and the production efficiency is improved.

The invention discloses a secondary hole sealing method for an underground coal mine gas drainage drill hole. The secondary hole sealing method comprises the following steps that (1) a bag type grouting hole sealing device and a two-blocking one-injecting hole sealing process are adopted for implementing first-time hole sealing and continuous drainage; (2) during gas drainage, a low-concentration gas drainage drill hole is selected, and a connected gas drainage pipeline is disconnected; (3) a sealing steel pipe is connected with a compressed air self-rotating drill bit and then inserted into a first-time hole sealing pipe, a high-pressure air supply pipeline is connected, and coal slag in the hole sealing pipe and the drill hole is cleaned through the compressed air self-rotating drill bit and high-pressure air blowing; (4) the sealing steel pipe is withdrawn, and a second-time hole sealing device is plugged into the first-time hole sealing pipe to a designed position; (5) grouting is conducted on the second-time hole sealing device for implementing secondary hole sealing; and (6) a hole sealing pipe of the second-time hole sealing device is connected into the gas drainage pipeline for gas drainage. According to the secondary hole sealing method for the underground coal mine gas drainage drill hole, the application engineering cost is low, the process is relatively simple, the drainage efficiency is fully improved, the drainage time is shortened, and gas disasters are eliminated to the maximum extent.

The invention discloses a vacuumizing system suitable for a mass spectrometer. The vacuumizing system comprises a first air exhaust unit and a second air exhaust unit. The first air exhaust unit comprises a molecular pump and a mechanical pump which are connected with each other, and an air exhaust opening of the molecular pump is connected with a vacuum chamber of the mass spectrometer; and the second air exhaust unit comprises a vacuum air path, an air inlet valve and a pre-extraction valve, one end of the vacuum air path is connected with a transition chamber of the mass spectrometer, the other end of the vacuum air path is divided into two paths, the first path is connected with the outside atmosphere through the air inlet valve, and the second path is connected with the vacuum chamber through the pre-extraction valve. According to the invention, the connection between the vacuum chamber and the transition chamber is realized by utilizing the pre-extraction valve, and the molecular pump can indirectly vacuumize the transition chamber through the vacuum chamber during vacuumizing so that the rapid pre-pumping of the transition chamber is realized, sample injection waiting time of a sample is greatly shortened, and the detection efficiency is improved.

The invention belongs to the technical field of coal mine safety, and relates to a coal seam region slicing, pressure relief and permeability increasing method based on a 'mining protective layer' principle. A slicer machine head reciprocates along a vertical gateway to cut a coal body; cut-off coal debris is conveyed out through a scraper conveyer; and a cutting boundary of a slicer moves along with a heading end at a certain speed in the direction towards an open-off cut of a stope face, sufficient pressure relief is realized on a coal body of a rear region due to a free space 200-300 mm wide cut by the slicer, an original gas pressure of a coal seam is reduced to close to zero (gauge pressure), and a gas permeability coefficient is increased by two or more orders of magnitude. By meansof the coal seam region slicing, pressure relief and permeability increasing method, sufficient pressure relief is realized on a protruding coal seam, the technical and economic problem that there isno protective layers for the protruding coal seam for mining is solved, and for those protruding mines where only construction of coal seam drilling and coal seam gas pre-drainage serves as a regionalanti-protruding measure, the brand-new solution of a regional anti-protruding technology is provided.