Breaking the top plate or thick coal layers spit Slicing generally used approach SHOP metal mesh, thereby forming an artificial prosthesis top - leave the top metal.
Most of China's existing thick coal seams (more than 6m) are divided into two layers (mainly referred to as fully mechanized mining face), and the upper layer mining is advantageous for lower stratification. The main measure is also to lay the metal mesh (currently using more paving nets), so that the fallen rock is cemented into a recycled roof. When using the shearer under such conditions, the following points should be noted:
(1) Always maintain the false top, maintain the integrity of the false top, and prevent the lower layer from falling and breaking the net. The miner driver should master the stratified mining height and strive to keep the bracket beam and the top net on the same plane to reduce the tensile force of the metal mesh and prevent the collapse accident due to the transitional bending.
(2) When cutting coal under the metal mesh, the drum of the shearer should not be cut near the top plate to avoid cutting the top net. It is generally required to leave a false ceiling of 200mm-300mm thick.
(3) When cutting coal under the metal mesh, especially when the stratification is adopted and the bottom plate is coal instead of rock, the coal mining machine must be cut flat, and the stepped bottom plate cannot be formed, otherwise it will cause difficulty in pushing and sliding. .
(4) In order to lower Slicing create good working conditions, eliminate or reduce the Fallen roof fall phenomenon, according to the nature of the stone slate roof caving in, water or take measures to inject mud mined-out area, prompting caving rock The cement forms a regenerated roof, which creates favorable conditions for the lower layer coal mining.
(5) When the thickness of the coal seam changes greatly, the driver of the shearer should master and adjust the mining height of each layer in time to avoid causing the underlying mining height to be too large or too small. It is difficult. To this end, after each stage of the mining strike, a hole is drilled every 10m-15m along the inclined direction in the working face, and the coal thickness is continuously explored to adjust and control the upper and lower stratification.
(6) When a large amount of coal is slumped, especially when large coal falls to the chute or near the shearer's sliding shoe, the artificial shearing should be carried out before the coal is loaded.
Second, the shearer crosses the fault
(1) The shearer crosses the fault
(1) When the fault is located in the middle of the working face, the drop is small, and the thickness of the nearby coal seam is larger than the diameter of the drum, the working surface can generally be pushed hard and the method of leaving the bottom coal is adopted. That is to say, a piece of triangular coal is left on the bottom plate (increased coal loss). If you do not leave the bottom coal, you can also pad the raft on the bottom plate to maintain a certain slope to ensure the smooth passage of the shearer and conveyor. At present, more is to adopt the method of leaving the bottom coal.
(2) When the fault of the working face is large, and the thick coal near the diameter of the drum is used, the bottom of the drum is generally used to make the shearer pass smoothly.
(3) When the fault is close to the upper and lower flat roads, the drop is large, and it is difficult to handle, then another section of the alley can be used to connect the contact eye with the original flat road to shorten the working face and avoid the fault.
(2) Shearer over-sloping fault
(1) For the slope where the drop is approximately equal to or less than the thickness of the coal seam (the slope is oblique to the working face), the method of letting the shearer hard is generally adopted.
(2) When the shearer passes through the fault, if the coal wall direction and the fault line are parallel or intersect with each other, the angle of the fault will be large, which will cause the roof pressure to increase sharply and the roof maintenance will be very difficult. . Therefore, in order to make the intersection area of ​​the fault and the working surface as small as possible, the direction of the working surface should be adjusted before passing through the fault. Generally, when the working surface is about 15m away from the fault, the working coal wall and the coal seam are kept at a certain angle. The larger the angle is, the smaller the cross-sectional area is, the easier the maintenance of the roof is, but the time for passing the fault is relatively extended. According to experience, it is generally considered that the angle of intersection is preferably between 250 and 400.
(3) When the shearer passes through the fault, special attention should be paid to the change of the slope of the floor, the breaking of the roof and the hard rock. When the Platts coefficient is below 4, the shearer can be used for direct cutting; if the rock hardness is higher, the method of pre-picking or starting is adopted by means of eye-opening. When the roof is broken, the movement of the bracket should be well matched with the shearer. It should be moved immediately after the coal is cut in front of the shearer.
(4) When the shearer passes through the working face fault, no matter whether the fault is on the upper or lower part of the working face, the bottoming method should generally be adopted. Try not to use the topping to avoid damage to the stability of the roof rock formation and increase the maintenance. difficult. Since the roof of the cut-off layer is relatively broken, the bracket adopts a method of rubbing the top.
(3) Use of shearer in inclined coal seam
China's inclined coal seam reserves account for a certain proportion, so it is important to use the coal mining machine in the fully mechanized mining face of the inclined coal seam, and pay attention to many problems.
(1) When using the chain traction shearer, if the inclination angle is greater than 150, the hydraulic safety winch must be used and there is a reliable anti-skid device; when using the chainless traction shearer, there must be a reliable anti-skid device.
(2) In the working face with an inclination angle greater than 300, from the perspective of reducing transportation equipment and power consumption, self-slip transportation should be adopted as well.
(3) Once the shearer breaks in operation, the conveyor should stop immediately, and the non-slip bar will be inserted into the conveyor scraper to prevent the shearer from sliding down. Therefore, it is required to have a safety interlocking device for the shearer chain breaking and conveyor stop.
(4) For coal seams with large dip angle and hard coal, the coal mining machine should adopt one-way coal cutting, that is, cutting coal along the working face, running the empty knife upwards, and cutting the coal into the same way. In this way, the shearer can be prevented from slipping when the coal is cut upwards, and the traction and traction speed is too slow, especially when the coal is hard and the large coal cut by the front drum is stuck in the shearer.
(5) In order to ensure safety, a synchronous anti-skid winch can be added to the upper level. When the shearer cuts coal, the driver can use the carrier signal and the winch driver to cooperate.
(6) Coal seam with large dip angle. When the coal mining machine cuts coal, the tensioning device of the upper roadway should be firm and reliable, and have sufficient tension, especially the shearer driven by the flat sprocket. It is not fast, and there will be a chain break accident due to the card chain and the feed chain.
(7) Coal seam with large dip angle, when using the shearer driven by the flat sprocket to cut coal, the shearer fuselage must have a solid chain guide device to prevent the traction chain from pulling out the guide chain.
Product Details
ESD PC Sheet has excellent anti-static function, high surface hardness, excellent scratch resistance, smooth and flat appearance, light transmittance of over 83%, excellent fireproof performance,Anti-impact, anti-UV, light weight, flame retardant and other properties.
|
Product |
Thickness(mm) |
Size(mm) |
Color |
Density(g/cm³) |
|
ESD PC SHEET |
8-100 |
610*1220 |
clear |
1.2 |
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