322,091. Jung, H. Nov. 27, 1928. Block filters; filtering- media. - A number of tubular filter elements 2 are suspended in rows from a partition wall 9 within a closed receptacle 1, the wall 9 having transverse channels 15, each receiving filtered. liquid from a row of elements 2, and also apertures 10, which allow of the upward passage of some of the liquid under treatment. The liquid is supplied to the receptacle through pipes 54,. 3 , 3, is distributed by apertures 6 in a plate 7, flows lengthwise past the filter elements, part filtering into the elements and the rest passing through the apertures 10 and being returned to the storage vessel through a pipe 12. The channels 15 discharge the filtrate into a common collecting pipe 17. An air supply pipe 18 connected to the pipe 17, has branches 18 , 18 to the pipes 12, 3 . The pipe 3 has branches 56, 58, 60 which serve respectively for the return of unfiltered liquid to the storage tank preparatory to a cleaning operation, for the supply of lixiviating liquid and for the supply of wash water. With the connections as described it is possible after a period of filtration, to expel all liquid from the receptacle 1 by supplying compressed air through the pipe 12, to lixiviate the cakes formed around the elements, to discharge the cakes by means of compressed air supplied to the elements through the channels 15 and to wash the filter elements by water, supplied to the receptacle from the pipe 60 and agitated by air supplied through the pipe 3', and, if desired, from within the elements. The bottom 5 of the receptacle, which is opened for the discharge of the cakes, is pivoted on a counterweighted lever 39, and clamped against the lower edge of the cylindrical wall by means of a bayonet joint device with wedges 48, which are moved by hydraulic pistons 49, Fig. 4. The pipe 3 which makes joint with the lower end of the pipe 3 moves with the bottom 5. The filter elements are built up of rings 25, Figs. 6 to 8, of ceramic or stone-like material, such as quartz, infusorial earth or silicon carbide which may be reinforced by material capable of bearing high stresses. Such reinforcement may comprise rings coated with glass, enamel, or other binding flux or formed wholly of the flux material. Annular discs 26, Fig. 8, of celluloid or vulcanite, or of the materials sold under the registered Trade Marks " Bakelite " and " Pertinax," may be attached to the surfaces of the rings 25, or these surfaces may be coated with enamel or by spraying with atomized metal. Each element has an inner carrier tube 21, fixed in the partition wall 9 by means of a collar 22 and screw cap 20, and having perforations 14, 30, within the channel 15 and the lower end, where the hollow body formed by the rings 25 is continued by a cylinder 29 of metal, vulcanite or other strong material.. The rings 25 are spaced from the tube 21 by longitudinal members 33, Fig. 7, of rubber or like material. Electric rings of rubber, klingerite or the like may be interposed between the rings 25 or between groups of the rings.