Filtering separators with dust feedback

In a filtering separator of the kind having a lower inlet for dust-or smoke-laden gas containing extremely adherent dust particles which is directed upwards towards filter elements, the dust which settles when the filter surfaces are periodically cleaned being carried back to the filter surfaces by said smoke-laden gas for agglomeration purposes, and a proportion of the agglomerated dust which corresponds to the quantity of dust in the incoming dirty gas and which the said gas is not capable of carrying with it to the filter surface being extracted during the periodic cleaning of the filter elements, the improvement of a container arranged within the separator and underneath said filter elements, said container constituting a collecting zone, and occupying a portion of the downwardly projected area below said filter elements, the dirty gas being directed to flow through said container, and said having a perforated wall and being filled with bodies around which the dirty gas flows, force-applying means being provided in association with said container to vibrate said bodies and detach the dust which clings to said bodies and collects between them, the said force-applying means being operative to make an at least intermittent application of force, and the coarse dust which enters the collecting zone when said filter elements are periodically cleaned being broken down by the vibrating bodies until it is able to be carried back to the filter elements by the dirty gas.