Study on dependency of rolling velocity and vibration acceleration in a rolling roller on fine coals upon the running velocity

Abstract

Coal thermal power stations occupy for approximately 40% in the world. It is required that the efficiency of the station would be improved in order to prevent environmental pollution. Then, it is important to pulverizing a large amount of coal in the vertical roller mill. However, self-excited vibration might occur as most of coal become final. It is unclear that what kinds of friction property could be related to be self-excited vibration, as one of the causes self-excited vibration in the negative friction properties were suspection. In this paper, we examine the rotating speed variation caused by roller slipping and the horizontal acceleration vibration of the rotating roller about 3type of coal. We use experimental equipment a specific vibration characteristic, where the occurred vibration could be observed. As a result, the higher natural frequencies about the structural system have changed into the lower. To investigate dynamic responses of the rolling roller, the rotating velocity of the roller, acceleration at the axis of rollers, the generated forced and etc. were measured. As a result, both the rotating speed variation and the horizontal vibration acceleration gradually increased in accordance with the running velocity of increase before decreasing at higher running velocity about 3type of coal.