Study On The Coupled Characteristics And Control Of Liquid Shake In Ladle Hanging

The casting crane for lifting molten steel ladle will cause the oscillation of the steel wire rope during the lifting of molten steel.The oscillation of the steel wire rope will be coupled with the oscillation of the molten steel.During the lifting process,the oscillation of the molten steel caused by the periodic oscillation of the ladle will in turn cause the center of gravity of the ladle load to shift.This impact will affect the anti-oscillation,precise positioning,and operation of the large and small vehicles of the lifting system,And subsequent processes such as pouring will have many adverse effects.At a light level,it can prolong the operating time of the ladle lifting system,leading to cooling of the molten steel,reducing the quality and efficiency of the castings.At a heavy level,it can cause splashing of the molten metal,leading to safety accidents.Currently,there is insufficient analysis and precise positioning research on the coupled characteristics of swing liquid swing of casting cranes for lifting molten steel ladle,especially in the harsh environment during steel lifting,which has brought many inconveniences to the research.Therefore,conducting research on the coupling problem of hanging and liquid shaking in the ladle lifting system has significant engineering significance and practical value.At present,there is little research on the dynamic characteristics and system control of the ladle lifting system considering liquid steel shaking.This problem is divided into four sub-topics,namely,container liquid shaking problem,liquid shaking modeling problem,liquid shaking suppression problem,and crane anti swing problem.To study the coupling situation and influencing factors of liquid steel shaking and hanging during the ladle lifting process,the motion equation of liquid steel shaking inside the ladle was derived based on potential flow theory,Obtained the shaking pressure and dynamic pressure moment generated by the excited shaking of the molten steel in the ladle;An equivalent mechanical model of the ladle lifting system was established based on the principle of equivalent dynamics,and its motion equation was derived;A multi body dynamics two-phase flow finite element coupling model for the ladle lifting system was established for finite element numerical simulation,and an experimental model was built for testing,proving the accuracy of the established finite element coupling model;By comparing the swing angle and steel wave response of the finite element coupled model and the equivalent mechanical model under different working conditions,the effectiveness of the established equivalent model of the ladle lifting system containing third-order modes was verified;Then,based on the established finite element numerical model,the influence of different parameters on the ladle lifting system was analyzed.The results showed that the swing amplitude of the steel wire rope first increased and then decreased with the increase of the rope length,reaching its maximum value around 8 meters long,and the swing amplitude increased with the increase of the trolley acceleration.The severity of liquid steel shaking decreases with the increase of liquid loading rate in the steel ladle.The shaking of molten steel will decrease as the length of the steel wire rope increases,but this effect will become smaller as the liquid loading rate of the steel ladle increases.Finally,based on the established equivalent mechanical model,a cascaded input shaping controller is used to suppress the wire rope swing and liquid steel swing of the ladle lifting system under trapezoidal velocity excitation,sinusoidal acceleration excitation,and sinusoidal velocity excitation.The results show that the cascaded input shaping control scheme designed in this paper can effectively suppress the wire rope swing and liquid steel swing generated by the ladle during high-speed flat lifting.