Hydraulic acrow props is a kind of mechanical equipment. It should follow certain principles when using it. It can't be used blindly, otherwise it will not have corresponding effect. So, we summarized the following points for attention about hydraulic prop.
1. The construction site of hydraulic pump station is not reasonable, which causes the output pressure of high-pressure gun to be small. In addition to type selection, the output pressure of pump station is very important for the initial support force of hydraulic prop.
In some coal mines, the hydraulic pump station is built at a distance of km from the mining face. The output pressure loss of the hydraulic pump is large and the initial support force is reduced when the column is driven, which has a great impact on the control of composite roof.
2. The stiffness of the support system is poor, and the base area of the hydraulic acrow props is small, especially the annular base. Under the condition of soft floor rock, with the mining advance of coal seam, the roof subsidence makes the pillar drill to the bottom, the movable column has small shrinkage, the liquid pressure increment in the cylinder body is small, and the support resistance cannot go up, which makes it unable to work under the rated working resistance and achieve the expected supporting effect of single hydraulic prop.
Therefore, in the main roof, periodic weighting period, the roof will appear step sinking and broken, which is easy to lead to the working face cutting along the coal wall, pushing the face dangerous. Because of the slow speed reading, the larger the roof subsidence, the more broken the roof, the more difficult it is to push forward, thus forming a vicious circle.
