Abstract: This invention relates to apparatus for charging and emptying filter material in a continuous filter silo for the purification or cleaning of flue gases, and in one embodiment comprises a layer of filter material is located between two substantially vertically arranged wall sections which have apertures, and wherein the layer of filter material, defined by the wall sections which are of annular cross section, is subdivided by at least 4 vertically arranged intermediate walls into segments, and wherein means are provided for the controlled feed of flue gases such that selectively two of the segments at a time are excepted from the action of flue gas, thereby permitting the renewal of the filter material, while the remaining segments being under full action of flue gas.