Research On Performance Of Magnetic Fluid Seals At High Rotate Speed Condition

In the neutrino experiment,the preparation of liquid scintillation is an important link.The sealing problem of the centrifugal extractor has become a technical problem to be solved with its high line speed condition and high cleanliness requirement.The magnetic fluid seal has the advantages of zero leakage,high speed resistance,no pollution,high reliability and long service life,and has become an important research topic to solve the sealing problem of the centrifugal extractor.In order to solve the problem of high-speed magnetic fluid sealing,this paper explores the relationship between line speed,temperature,torque and pressure from the aspects of theory,simulation and experimental research,and obtains high-speed magnetic fluid sealing performance.To solve the problems faced by high-speed magnetic fluid sealing,aneffective solution is proposed.This paper completed the following research:(1)Comparing the magnetic fluid of various base carriers and surfactants,the most cost-effective ester-based magnetic fluid is finally selected.The density of the ester-based magnetic fluid was obtained by measuring the mass under different volumes,and the saturation magnetization of the ester-based magnetic fluid was measured by a vibrating sample magnetometer.The rheological properties of the ester-based magnetic fluid were measured by rheometer,and the shear rate was less affected by the viscosity of the magnetic liquid,and the temperature had a greater influence on the viscosity.(2)A plane sealing test bench was built.The mechanism and failure mechanism of magnetic fluid were studied through the combination of theory and experiment.The magnetic fluid seal is related to the gap size,the volume of the magnetic fluid,the number of stages,etc.It is observed that the seal failure is divided into two stages,namely the micro-leakage stage and the liquid film rupture stage.(3)For the research of high-speed magnetic fluid sealing,a high-speed magnetic fluid sealing experimental device was designed.The ANSYS was used to simulate the tooth profile,clearance,tooth height and tooth width of the pole shoe.The shape of the pole shoe was designed by considering the machining and pressure resistance.In view of the heating problem in high-speed working conditions,the pole shoe cooling scheme was designed and the core cooling was proposed.(4)The magnetic field and temperature field simulations of the seal structure were carried out by ANSYS.The magnetic induction intensity cloud map and the magnetic field line distribution diagram show that the seal structure design is reasonable and the theoretical withstand voltage of the seal is obtained.The temperature distribution under high-speed conditions was obtained by temperature field simulation.The core cooling and pole shoe cooling were included in the simulation.It can be seen that the system temperature dropped significantly.(5)A high-speed magnetic fluid sealing test bench was built,and the dynamic and static sealing and temperature influence experiments were carried out.The correctness of the simulation was verified and the relationship between temperature,pressure,torque and line speed was obtained.The experimental results show that temperature and centrifugal force have a great influence on the sealing withstand pressure.Adding cooling can effectively reduce the temperature of the magnetic fluid,improve the sealing ability.Figure 76,table 19,reference 103 articles.