磁流体液体动密封中界面稳定性的研究

In this project, magnetic fluids which don't dissolve with oil have been prepared by chemical coprecipitation method and their properties such as magnetic property, thermostability, volatility and causticity were investigated. Then studies are made in detail on the formation mechanism of magnetic particles and the influence of surfactant on the properties of magnetic fluids. In order to maintain the interface instability between magnetic fluid and the oil to be sealed in the applied magnetic field, a test apparatus has been designed according to the disabled reason for magnetic liquid seal and the influence elements of the interface stability have been studied. The magnetic field leakage has been effectively controlled by optimum designing the magnetic circuit in seal structure. Magnetic fluids viscometer has been developed and the viscosities of magnetic fluids were measured. Results indicate that viscosity of the magnetic fluids is related directly with the concentration, temperature and magnetic field, which is consistent with theoretical analysis. Furthermore, the influence of the velocity difference between magnetic fluids and the oil to be sealed on the interface stability has been investigated.

磁流体尚未用于液体轴密封的关键难题是如何维持它们之间界面的稳定，为此需研制与被密封液体完全不相溶且在磁场中呈不同粘度的磁流体，以达到界面两侧液体等速旋转的目的；研究磁路的设计方法，使密封间隙处磁场足够强、界面处磁场低于破坏界面稳定的阈值。使零泄漏、无磨损的这种密封方式能用于电子信息、制药、食品、船舶、机械制造等产业。