WATER TREATMENT DEVICE FOR PREVENTING BREAKUP OF FILTER LAYER

摘要

PURPOSE: A filtering device is provided to remove fine filtering dust and foreign materials precipitated in filtering materials based on magnetic forces in a backwashing process. CONSTITUTION: A filtering device consists of a housing (110), a lower filtering layer (120), an upper filtering layer (130), and a magnet (140). The lower filtering layer is based on magnetic filtering materials. The magnet is adjacent to the lower filtering layer. The upper filtering layer is based on filtering materials having larger particle sizes and lower specific gravity than the particle sizes and the specific gravity of filtering materials in the upper filtering layer. A second magnet is arranged on the upper side of the upper filtering layer. The magnet and the second magnet are electromagnets which are in electric connection with a power supply. The second magnet generates a magnetic force only when a backwashing line (160) operates. After the second magnet generates the magnetic force, the magnet generates a magnetic force before and after the termination of the backwashing operation. When a filtering line operates, no magnetic force is generated. The second magnet is in a net form. Meshes of the net are smaller than the filtering materials in the upper filtering layer. Filtering materials in the upper filtering layer are blocked by the second magnet in the backwashing process.