Filter wall of double-layered paper - presents maximal area to flow passing through larger pore layer first

摘要

The total flow of a liq. to be filtered, such as oil, is made to pass successively through a double wall of filter paper, starting from the surface of the paper elements in which the pores are larger. The filter wall may be folded in the form of a star to give the maximum contact area for the height and diameter. It is formed from an outer element in which the pores may be from 25-35 mu and a downstream element with pores 8-15 mu. Moreover, the outer layer is of a plush type paper. The arrangement effectively lengthens the working life and the efficiency of filters of the same size working under the same conditions.