Motion analysis on the particles in a magnetic field detector

This paper, as the title indicates, deals with the depositing mechanism of the particles under the magnetic field in the lubricant for on-line ferrograph or oil analysis. Lubricant, containing ferromagnetic particles, is taken as the multiphasic ferromagnetic fluid in ferrograph detecting. By measuring and regressing, the distribution formulas of magnetic density and magnetic density gradient of an electromagnet are gained. The variance law of viscosity of lubricant in the non-uniform magnetic field is studied and a viscosity formula is put forward. The motion law of ferromagnetic particles in the non-uniform magnetic field is studied and a standpoint is put forward, which is that the ferromagnetic particles cannot achieve a constant sinking velocity in a non-uniform magnetic field. The factors influencing particles motion, such as particle diameter, ratio of particles volume and air bubbles, are also studied. Some results are obtained and discussed, which are of practical significance in the research and design of on-line ferrograph and other methods of on-line oil monitoring.