When the working face is approaching the old lane, first clean, repair, and reinforced the bracket in the old lane. Under the original bracket, put a beam and two columns or a beam and three columns of joist shed; if the old lane bracket has a partial fall, use crib pick the top; when slice mining, but also pre-laid metal or plastic mesh top.
When the roof of the old road is broken and the pressure is high, the working surface cannot be propelled in parallel with the old road. The direction of the working face should be gradually adjusted when approaching the old alley, so that the working face is oblique to the old alley. In this way, the old lanes occupy a small area in the working space, even if the roof of the old lane is broken and the pressure is large, it is easy to control. When the gun is mined, put a small cannon or a vibrating gun as much as possible to reduce the damage to the roof. The control roof area at the intersection of the working face and the old lane should increase the support density and add rafts.
If the old lane is above the working surface, use a long wooden beam top that is larger than the width of the old lane. The wooden beam stretches out the wall of the coal wall and puts it on the pillar. The long wooden beam is tightly tied with wood, and then it is lifted in the inclined direction. After the conveyor is moved, the raft is placed on the side of the gob.
When mining thick coal seams, the old lanes are mostly below the working surface. Before the old lane, it should be filled with vermiculite and coal. When the working surface is advanced to the old lane, the bottom plate is to be lowered with a long bottom beam, and the pillar is supported on the bottom beam to prevent the pillar from sinking. In the old alley, you should add a wooden raft top.
The working face passes through the old lane, and it is necessary to speed up the advancement to reduce the pressure on the roof and prevent the roof from falling.
Metal Sheet Laser Cutting Machine
What is the metal sheet Fiber Laser Cutting Machine?
Metal sheet laser cutting machine can only cut metal material in sheet. If you want cut metal tube, we have a special metal tube fiber laser cutting machine. If you want cut both metal sheet and metal tube, we also have metal Tube And Plate Fiber Laser Cutting Machine. It has the advantages of fast cutting speed, high precision, small area of heat affected area, stable performance, guaranteed continuous production, not easy to deform, smooth and beautiful cut seam, and no need for subsequent processing. Compared with other metal laser cutter, fiber laser cutter can complete the processing of various complex structures. As long as it can draw any image on the computer, the machine can complete the processing without opening the mold, and the product can be produced immediately. That is, new products can be developed quickly and costs can be saved. No matter how complicated the process requirements are, fiber laser cutting machines can do it.
Therefore, with the above processing advantages, fiber laser cutting machines are widely used in advertising sign production, sheet metal structure, high and low voltage electrical cabinet production, textile machinery parts, kitchenware, automobiles, machinery, elevators, electrical parts, spring sheets, subway parts, etc.
Why to choose the fiber laser cutting machine?
1. High cutting accuracy: The positioning accuracy of the metal laser cutter reaches 0.05 mm, and the repeated positioning accuracy reaches 0.03 mm.
2. Narrow slit: The width of the slit is generally 0.10-0.20 mm.
3. Smooth cutting surface: There is no burr on the cutting surface, and the roughness of the cut surface is generally controlled within Ra 6.5.
4. Fast cutting speed: the cutting speed can reach 10 m / min, and the maximum positioning speed can reach 30 m / min.
5. Good cutting quality: Adopting non-contact cutting, the cutting edge is affected by heat little, there is basically no thermal deformation of the work piece, to ensure that the work piece is not scratched, and the slitting generally does not require secondary processing.
6. Laser processing has good flexibility: the fiber laser cutting machine can process arbitrary graphics, and it can cut pipes and other profiles without being affected by the shape of the work piece.
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Jinan Transon Cnc Equipment Co., Ltd. , https://www.csjiguang.com