Patent ID: 8864989
Filing Date: 2014-10-21
Classification: B01D,C02F,Y02W

Abstract:
1. An upward-type filtering apparatus, comprising: a pressure container that defines a rigid ceiling, an outlet port located in the ceiling, and filtering material which is placed in the pressure container and which is made of gravels, filtering sands and particles, in which to-be filtered water is supplied from a lower portion of the pressure container and is filtered upward, and filtered water is obtained from an upper portion of the pressure container via the outlet port, wherein the filtering material comprises a filtering portion including a plurality of layers which are laminated on one another such that particle diameters thereof are gradually reduced from a lower portion toward an upper portion of the filtering portion, and a filtering sand flowing-out preventing portion including a plurality of layers which are located on the filtering portion and which are laminated on one another such that particle diameters thereof are gradually increased from a lower portion toward an upper portion of the filtering sand flowing-out preventing portion, wherein the filtering material is charged into the pressure container such that an entire volume of the pressure container is filled with the filtering material and an upper layer of the filtering sand flowing-out preventing portion of the filtering material reaches the ceiling of the pressure container, and wherein the to-be filtered water can be supplied into the lower portion of the pressure container under a water pressure of 0.05 MPa or higher.