JPS5522499A - Filtering device - Google Patents

Abstract

PURPOSE:To discharge filter refuse easily, while maintaining the optimum filtering state, by displacing the nontransmissible plate, which separates the fluid chamber from filtering chamber, with the secondary pressure of fluid, and changing the volume of the filtering chamber in enclosed state until the filter refuse inside may be pressed together. CONSTITUTION:When the raw liquid is forced into a filtering chamber A through communicating holes 5a, 9a from lead-in pipes 7, 11, rubber bag 2, water passing net 3, and filter cloth 4 are pressed against the inner wall of filter body 1, and filtration is performed in this state. The filtered water passing through the net 3 is introduced into sampling pipe 14, and filter refuse layer S is deposited on the surface of filter cloth 4. When the layer S develops above a specified thickness, water is supplied into the fluid chamber B in each bag through feed pipe 12 and communicating pipe 13 at a pressure higher than the raw liquid force-in pressure, then the raw liquid is discharged in back flow, and the filter refuse is pressed together. When the water is discharged from chamber B, the raw liquid fills up the chamber A, so that the pressed filter refuse Sa is partially deposited to become in the state of Sb. By repeating this cycle, when the pressed filter refuse is enlarged to state Sc, compressed air is sent in from feed pipe 8, and the separated filter refuse is dropped down by gravity by opening the bottom lid 9.