Liquid-solid Coupling Vibration Analysis And Experimental Study Of The Sink Roll Device In Hot-dip Galvanized Line

Hot-dip galvanizing which is a plate strip surface treatment method,is the most widely used and cost-optimal.As one of key functional components of the hot-dip galvanizing process,the sink roll device will affect the production,maintenance cycles and plating piece quality if some abnormal vibration once appeared.The sink roll device has the effect of liquid-solid coupling vibration and the complex of vibration mechanism in zinc liquid.At present,there is no research on the theory and experiment of the liquid-solid coupling vibration of the sink roll device,so the research content of this paper have major significance for the engineering application.Based on the summary of a large number of domestic and foreign literature,to study the liquid-solid coupling vibration characteristics and the structure design for vibration reduction of sink roll device,the relevance theories of the structural non-complete liquid-solid coupling and added mass model and dynamic response were analyzed,the corresponding experimental study was carried out.The main contributions of the research include:(1)According to the motion characteristics of the sink roll device,the non-complete liquid-solid coupling numerical method based on wet modal and the generalized liquid added mass method were studied,and a theoretical basis was provided for further research of this paper.(2)Based on the wet modal of non-complete liquid-solid coupling numerical method,the numerical model of sink roll device was established,and the natural frequencies and vibration modes in liquid zinc were analyzed;Combined with the field vibration experiment,the frequency domain information was achieved,the wear reason of structure was discussed,and the validity of this numerical model was verified.(3)Based on the added mass theory,each order modal of generalized added mass of the structure in liquid zinc was calculated;The numerical model used for correction of added mass from the dominant mode was determined by the law of the response from the experiment study;As the external incentives of the moving steel strip,the transient dynamic response based on added mass of the sink roll device was studied,and the mechanical analysis of the structure was made.(4)By the findings of the wet modal and dynamic response,the external factors such as liquid properties,strip tension and the wrap angle,and the structural design factors such as roll wall thickness,roll diameter and cantilever thickness were studied for the impact and the rules of the natural frequency in vibration system;And the influence of the increase of the strip's sinusoidal excitation on the bearing was analyzed.Based on the above research,the design methods and suggestions for the vibration reduction of the sink roll device were proposed.