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

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 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.

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 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 discloses a method for uncovering coal in a stone gate of a gently inclined extra-thick coal seam, which is especially suitable for protruding dangerous coal seams with a small inclination angle and a large thickness in a coal mine. When the Shimen is excavated to a vertical distance of 12m from the coal seam, excavate an inclined stone gate on the right side of the Shimen, and when the inclined stone gate is excavated to a vertical distance of 7m from the coal seam, a floor roadway is excavated in front of the Xieshimen. The floor roadway is parallel to the Shimen and excavated along the coal seam . A plurality of drilling sites are evenly arranged in the completed floor roadway, and the coal seam gas is pre-extracted by hydraulic slotting drilling from the drilling site to the coal seam. After the gas drainage reached the standard, Shimen resumed excavation in the original direction, and passed through the coal seam and entered the roof 2m to complete the coal uncovering work. Through the construction of the floor roadway, the present invention transforms the slow-sloping long drilling that restricts the speed of uncovering the coal into the floor-penetrating drilling, which breaks the bottleneck problem of slow coal mining in the gently inclined and extra-thick coal seam, and realizes safe and fast coal mining, which has a wide range of applications. practicality.