DE2500990

The invention relates to filter candles of the type in which the fluid medium flows through a circumferential wall into the interior of the filter and the particles are collected at the outside. The circumferential wall is formed of sectional members defining narrow slots between them. At intervals the stream of fluid is interrupted and a reverse fluid pressure pulse is effected in the fluid inside the filter of sufficient magnitude to enlarge the slots to create a back flow of fluid through the enlarged slots to remove thereby the accumulated particles from the slots.