Research on locating control method of ball mill based on prediction
To solve the difficulty of precise locating of large inertia ball mill, a new method based on prediction is put forward. The feasibility of this method was analyzed using the motor theory and analysis on the ball mill kinematics and dynamics. The equipment to install rotary encoder that was connected to the ball mill was designed. And the testing hard ware based on single-chip microcomputer was build, and data of the angle and the rotational speed of the ball mill were acquired. With the tool of Mat lab, data were analyzed. The results shows that the angle predicted from the starting stage is very much closed to the angle which is measured, and the tolerance is very small, and it can meet the application completely.
Research on precise locating control of large inertia ball mill
To solve the problem of difficulty in precise locating of batch ball mill, the kinetic model was build, and parameters relationship between starting and shutting down were analyzed, control system was designed. At the stage of starting of ball mill, load torque, rotary inertia and so on could be acquired. Based on the relationship of ball mill kinetic parameters between starting and shutting off, parameters at the stage of shutting off could be predicted. With these parameters, the angle that the ball mill would roll after power off could be predicted. With the angle, the optimum spot to cut off power of ball mill could be find, and precise locating and stopping of ball mill could be implemented. The control system is simple in structure, easy for installation and suitable for the reconstruction of existing ball mills control.
Physical Ageing of the Research Reactor Core Structural Materials Due to Neutron Irradiation Exposure: a Review
A research reactor (RR) is a  nuclear reactor that has function to generate and utilize neutron flux and radiation ionization for  research purposes and industrial applications. More than 60% of current operating RRs have  been operated for 30 years or more. As the time passes, the functional capabilities of structures,  systems and components (SSCs) of those RRs deteriorate by physical ageing, which can be  caused by neutron irradiation exposure such as irradiation induced dislocation and  microstructural changes. To extend the lifetime and/or to avoid unplanned outages, ageing on  the safety related SSCs of RRs need to be properly managed. An ageing management is a  strategy to engineer, operate, maintenance, and control SSC degradation within acceptable limits. The purpose of this study is to review physical ageing of the core structural materials of  the RRs caused by neutron irradiation exposure. In order to achieve this objective, a wide range  of literatures are reviewed. Comprehensive discussions on irradiation behaviors are limited only  on reactor vessel and core support structure materials made from zirconium and beryllium as  well as their alloys, which are widely used in RRs. It is found that the stability of the mechanical  properties of zirconium and beryllium as well as their alloys was mostly affected by the neutron  fluences and temperatures.