FILTER

摘要

A filter element (10) is provided comprising an elongate hollow structure having a closed end (12) and an open end (14). The filter (10) has an inlet comprising the exterior surface (16) of the filter element and an outlet comprising the open end (14). The filter has a re- entrant cross sectional shape traverse to the longitudinal axis of the filter element having an scalloped outer edge defined by equal curved sections and an inner edge defined by equal curved sections. The curved sections of the inner edge are aligned with the curved sections of the outer edge forming a filter wall (18) therebetween. The filter wall (18) comprises a radial array of self supporting arches.