Filter structure for filtering a particle-containing gas, method of its manufacture and use of porous paper

摘要

The invention relates to a novel gas filter structure, a filtering method and a method of producing the filter structure. The structure according to the invention includes a planar, porous isolation material layer (12) having two opposing surfaces. According to the invention both surfaces of the isolation material layer (12) include comprise a porous conductive layer (14, 16) including a porous filtering matrix treated with a conductive material. The conductive material consists of a material different from the support matrix. By use of the conductive layers it is possible to create in the isolation material an electric field that considerably improves the filtering efficiency of the isolation material, especially for small particles.