The DN internal injection type hydraulic prop working fluid is No. 5 hydraulic oil. When the column is returned to the column, the hydraulic oil flows back into the inner cavity of the living column to form a closed loop; no pump station and piping system are required, and the supporting equipment is small and the cost is low; It can be used in places where there is no power supply and pumping station. It is flexible, easy to manage and simple. Because the working fluid is closed loop, the hydraulic oil flows back to the inner cavity of the column when the pillar returns to the column, realizing the closed circuit circulation of the hydraulic oil of the pillar itself. The hydraulic oil consumption is very small; the hydraulic system of the pillar is a closed system, the hydraulic oil does not overflow, does not pollute the environment, is conducive to environmental protection, has little impact on the production of the working surface, better maintains the working surface environment, and has better working conditions; The valves are all installed in the inner cavity of the pillar, which is less likely to be contaminated by the outside and has high reliability.
DN Internal Injection Type Hydraulic Props
1. Coal seam dip angle: The gently inclined mining face with the coal seam inclination angle less than 20° can also be used for the mining working face with the inclination angle of 25°~35° after taking the measures.
2. Height: not more than the height of the pillar, that is, the DN18 type pillar support height is 1.8m, the support height variation range is generally 1.3-1.8m; the DN22 type pillar support height is 2.2m, and the support height variation range is generally 1.6-2.2m. and many more.
3. The pillar should not push the middle of the pillar as the fulcrum of the push-pull jack during the pressure-bearing process;
4. When using the working surface of the blasting, measures should be taken to prevent the surface of the pillar of the pillar from collapsing.
