An investigation on the shorter lifetime of pleated filter compared to flat sheet

In many cases, there is only limited space inside of the dust cartridge. To increase the filter surface area, the filter media are pleated to various extents to meet the filtration requirements. In many cases however, one can observe that a pleated medium exhibits a shorter lifetime than one would expect from the corresponding flat sheet media data. One of the reasons is that the changed flow resistivity of the folding region of the pleat has to be taken care of. The material in the inner part of the fold is compressed while the outer part is stretched. This change in the distribution of the material density directly influences the flow resistivity in the folding region. Eventually, the flow through the entire pleat and the distribution of deposited dirt will be affected, too: The fold ing region is less active than the straight part of the pleat. The aim of the study in this paper is to investigate these effects by analyzing the change of the flow resistance due to the folding of the medium. By taking into account this effect, our software can quantify the influence of the pleat shape (channel width, length, etc.) on the filtration efficiency and lifetime of the pleated filter.