GB774811A - Improvements relating to filters for fluids (liquid and gaseous) - Google Patents

Abstract

774,811. Filtering liquids. STEVENS, R. J. Aug. 19, 1955 [Sept. 14, 1954], No. 25093/54. Class 46. [Also in Group XXVIII] . In an edge filter having inlet and outlet sides for the fluid to be filtered and consisting of a pack of filter plates in face to face relationship with fine interfacial flow passages, clamps for holding together the filter plates, the inlet edges of the plates forming an edge face where part of the filtering action occurs, the balance being in the interfacial passages, and the bounding edges of the plates constituting entrances to the filtering medium, electro-magnetic means produce a momentary shock at each current impulse to disturb the edges of the plates and dislodge therefrom any accumulations of dirt tending to clog the entrances or to prevent the formation of such accumulations. The filter unit A comprises a pile of discs of iron, nickel or other magnetic material each formed with two sets of radial slots OL, IL, Fig. 3, and with the intervening material or strips S channelled to provide filter passages n, o, with an intervening plain portion p. One set of slots has T-shaped heads ; the slots of the other set are curved at their inner ends to meet the circle on which they end tangentially. The pile is held between feed and drain plates B, C themselves held between top and sump plates D, E clamped together by a bolt G extending therethrough from a bottom plate F to a cup-shaped outlet H for filtered oil. Oil enters by an inlet I on the top plate D and flows through an aperture J therein to an annular channel K in the underside thereof, whence it passes through distributer ducts L to the slots IL. After traversing the channels n, o to the slots OL, the oil escapes by outlets N<SP>1</SP> to an annular channel O in the plate B and thence to the outlet H. Separated particles descend ducts U to a sump s in the plate E. A magnet winding is threaded through a ring of holes m in the pile A and exterior to the plates B, C, pulsations through the winding vibrating the pile to dislodge and feed away separated particles. The magnetic flux may vary in frequency and the vibrations be of very small dimensions such as those due to magneto striction and have supersonic frequency. Modified forms of the filter plates have the slots OL, IL arranged reversely for outward flow or the slots are formed as divided concentric circles. The vibrations may be produced externally of the filter and be mechanically communicated thereto. In other forms the filter comprises a conducting coil of wire through which electric current is passed, filtering taking place between the convolutions, or parallel wires which may be of different lengths and thicknesses may be used. The pile A may be replaced by a strip wound edgewise into a flat coil.