Why are cartridge filters sometimes described as “edge” filters in clarification service?

Introduction / Context:
Cartridge filters employ wound fiber or pleated media to provide a tortuous path with a large surface area. Their retention arises from both surface sieving and depth capture, often described using “edge” terminology.

Concept / Approach:
The geometry of pleats or wound layers presents many “edges” where flow converges and fine particles are trapped. The bulk of solids removal occurs along these peripheral paths rather than a single flat face, hence the term “edge” filter. The term does not imply razor-sharp metal edges; it describes the interception mechanism.

Step-by-Step Solution:
Recognize cartridge morphology: pleated/wound depth media.Understand capture: edges and depth passages collect solids throughout the media.Therefore the “edge” label refers to periphery-dominant capture.

Final Answer:
Because most solids are intercepted along the cartridge edges/periphery (depth and edge effect)