Granular filter allows the filtration of gas by passing the gas containing the dust particles to be removed through a bed of granular material, for example gravel.
In the case of moving bed granular filter, a moving bed is used where the gas flows through the bed to remove the dust particles.
In this configuration, new media or washed media is continuously or intermittently added to the filter bed while a substantially equal portion of media which has accumulated substantial quantities of dust particles, is removed from the bed.