Patent ID: 8747667
Filing Date: 2014-06-10
Classification: B01D,C02F

Abstract:
1. A filter apparatus comprising: a vessel; a walnut shell filter media positioned in the vessel; a feed inlet positioned in the vessel; a draft tube system positioned in the walnut shell filter media and constructed and arranged to substantially roll the walnut shell filter media, wherein the draft tube system comprises a draft tube centrally located in the vessel and forming a peripheral zone positioned between a side wall of the draft tube and a side wall of the vessel; a gas inlet positioned below the draft tube and constructed and arranged to deliver a gas and create an upward flow of the gas and at least a portion of the walnut shell filter media in the draft tube and create a downward flow of at least a portion of the walnut shell filter media in the peripheral zone; a backwash fluid inlet positioned below the peripheral zone and constructed and arranged to deliver and create an upward flow of backwash fluid to the peripheral area to backwash the walnut shell filter media moving downward in the peripheral zone; a backwash outlet positioned in the vessel and above the filter media and constructed and arranged to remove backwash fluid from the vessel; and a filtrate outlet positioned below the filter media.