[en] The refillable particulate filter, e.g. of charcoal, for adsorbing radioactive impurities from a gas flow consists of a filter housing with a filter bed, arranged across the flow direction of the gas, and filling resp. discharging nozzles mounted above and below for the filter material. In the discharge nozzle the filter housing is designed as a funnel with a pipe extension. This one terminates at a distance over a bottom plate with which the discharge nozzle is closed. The filter material piles up on this bottom according to the angle of discharge. Diametrically opposite from it the discharge nozzle is connected with a blower via a discharge pipe for the filter material and a pressure pipe. In the discharge pipe there is mounted a porous trap before the blower in order to collect the discharged filter material. (DG)