| 摘要 |
<p>A vertical roller mill, comprising a pulverization table (3) which is accommodated in a housing (2), and rotated and driven by a table driving apparatus, two or more pulverization rollers (4) which are pressed against the upper side of the pulverization table and pulverized massive lumps and two or more roller pressure units (5) which press the pulverization rollers, wherein each of the roller pressure unit comprises a hydraulic cylinder (13) which applies the pressing force to the pulverization roller and a hydraulic circuit connected to the hydraulic cylinder, wherein an accumulator communicates with a pressure oil supply path of the hydraulic circuit, a first on-off valve is provided at the downstream side of a communicating position of the accumulator in the pressure oil supply path, a first bypass path which communicates with the downstream side of the communicating position of the accumulator in the pressure oil supply path and communicates with the downstream side of the on-off valve, and bypasses the on-off valve is provided, a first orifice valve and a second on-off valve are provided in the first bypass path, wherein the first on-off valve is opened and the second on-off valve is closed in a steady operation of the vertical roller mill (1), the first on-off valve is closed and the second on-off valve is opened at a time of the occurrence of the self-excited vibration so that a flow of an oil to the hydraulic cylinder due to the self-excited vibration is caused through the first orifice valve.</p> |
