Quantities of Pleated Filters
A pleated filter contains a folded filter medium to maximize the effective filter surface. The performance of a pleated filter is characterized by the three quantities:
- Pressure drop: equals the energy needed to operate the filter.
- Filter efficiency: the probability that a particle of a given size is filtered.
- Lifetime: the period of time after which the filter has to be replaced.
Relation between the Permeability, the Structure and the Quantities
The goal of the project is to establish a relation between the permeability of the filter medium, the channel structure of the pleated filter and the three quantities pressure drop, filter efficiency and filter lifetime. Therefore, we firstly generate a three-dimensional computer model of a particular pleat. In the second step, a flow simulation yields the initial pressure drop of the clean pleat.
Now, particles are put into the flow field. They move through the medium subject to friction forces, inertia and Brownian motion. Their motion is stopped in case of a collision and they deposit due to adhesive forces. Based on the ratio of deposited and not filtered particles, filter efficiencies are computed.