The performance of any filter is defined by three properties: pressure drop, filter efficiency, and dust holding capacity (DHC). The pressure drop defines in which way the pressure increases during the loading of the filter. The filter efficiency reflects how efficient the filter can trap particles of different sizes. The DHC measures the number of particles which a filter can trap and hold before the maximum allowable pressure drop is reached.

The ideal filter has a large DHC and a high filter efficiency while maintaining a low pressure drop. Those three properties usually influence each other, meaning that improving one or two of them will usually diminish the third property.

The pressure drop is important because it defines the amount of energy that is needed to operate the filter.

The filter efficiency can be quantified also by the so-called β-ratio, the ratio between the numbers of particles upstream and downstream of the filter.

The DHC is important because it specifies how long a filter can operate before it must be replaced or cleaned.

The aim of this tutorial is to optimize the filter media by increasing the dust holding capacity (DHC), while maintaining the pressure drop and β-ratio. Concretely, these side conditions are ensured by modeling all media in this tutorial to have initially nearly the same pressure drop (i.e. in the clean state) and the same β-ratio of 200 for particles with diameter of 22 µm or larger. The media thus is 99.5% efficient in removing particles larger than 22 µm.