GB1085087A - Improvements in or relating to filters - Google Patents

Abstract

1,085,087. Filters for liquids. WARNOWWERFT WARNEMUNDE VEB. April 5, 1965, No. 14336/65. Heading B1D. [Also in Division F2] A filter comprises two chambers 2, each containing a filter element 4, and a central hollow member 3 which forms the stationary part of upper and lower valves, the rotary parts 6, 5 of the valves being rotated by a handle 8 and a common shaft 7, and the valves having a position in which liquid delivered to inlet 12 passes through both chambers 2, in parallel, to outlet 13 (Figs. 5, 6, not shown) and second positions in which filtering flow continues through one chamber while the other is cleared by reverse-flow of compressed air or steam from an inlet (15) to the upper valve 6 and out by lower valve 5 to a sludge outlet (14) (Figs. 7, 8, not shown). The latter operation is performed on chambers 2 in turn by moving handle 8. At a third, intermediate position (Figs. 9; 10, not shown) liquid enters by a slot (21) in the lower valve rotor into the newly cleared chamber and air is vented from an outlet 16 via a part-annular groove in the upper valve rotor. Fig. 2 (not shown) illustrates three positions of the valve handle and the arrangement of parts 12, 13 and 14, 15, 16 vertically aligned on opposite sides of member 3. An improved valve structure (Figs. 11..16, not shown) incorporates pressure equalising passages and chambers in the valve rotors to avoid excess contact pressure between movable and fixed parts of valves under high working pressures.