Patent ID: 6468320
Filing Date: 2002-10-22
Classification: B01D

Abstract:
A filter unit for removing particulates from a gas to be treated, which comprises more than one gas impermeable bulkheads having a gas inlet, a filter member, and a gas shielding plate, wherein (1) said bulkheads are arranged such that a radius of said bulkheads decreases from an outer periphery side towards a center side of the filter unit, to form a channel, (2) said gas shielding plate is positioned in contact with said bulkheads between a gas inlet of an outer side bulkhead and a gas inlet of a center side bulkhead to allow communication between a channel and a gas inlet on a center side bulkhead and (3) said filter member comprises a nonwoven fabric having a density of 0.005-0.4 g/cm3, and being prepared using a fiber having 0.1-8 mmol/g of an ionic group and said filter member is laminated on at least one side surface of the bulkhead without closing said channel, and wherein the gas flows through said channel from an outer side to a center side in the filter unit, being discharged from the center portion, and advances in the filter unit at least 1.5 rounds through said channel.