Self-cleaning filtration with magnetically controlled particles

Abstract

Abstract In this work, a new concept of dynamic granular bed was proposed based on magnetically controlled particles. Compared with conventional moving granular bed, a rotating granular layer was formed on dynamic granular bed, which can capture solid particulates. The dust cake can be kept at a certain amount of thickness even after long-term operation. Self-cleaning function of dynamic granular bed installation provides a long-term operation. Hence, the backwash process is not required in self-cleaning installation. Rotating magnetic field was used for granular bed formation with a predetermined porosity in this work. Mechanism of a dynamic granular bed formation described using experimental and visual surface layer data. Periodic working moving granular bed is then changed to continuous and steady working dynamic granular bed. Numerical data of the main filtration process showed a good agreement with experiment. The experimental results show that there exist optimal parameters of filtration superficial velocity and mass flow rate of filter granules for dynamic granular bed. Best efficiency obtained at a filtration superficial velocity of 0.03 m/s and a mass flow rate of 10 l/h for dynamic granular bed in the experiments.