| 摘要 |
1. A filter with superimposed rings, for liquids, of the type with countercurrent cleaning and comprising a series of coaxial filter elements of annular shape, forming a unit of cylindrical general shape and leaving annular filtering passages between them, and comprising spacing members made of elastically deformable material, arranged locally between the filter elements, and means for varying the distance between the filter elements, without friction, by varying a pressure exerted on the said spacing members, in order to switch the filter from the filtration mode to the cleaning mode and vice-versa, the liquid passing between these elements from the central region towards the outside of the filter during cleaning and in the opposite direction during filtration, characterized in that, viewed in axial section, the part of the filter elements (12) which is nearest to the axis of the filter is in the shape of an arc which becomes thinner towards its inner edge (Fig. 1 and 4) and is such that the said arc-shaped parts overlap and, in their inner part, individually form an elementary deflector for the cleaning liquid and together form a succession of quasi-cylindrical partitions which only leave between them passages of which at least a part, near the axis of the filter, is oblique relative to this axis, and of which the orientation is such that the opening nearest to the axis of the filter faces the end at which the cleaning liquid enters the central part of the filter, in order to ensure that, during cleaning, the liquid flows between the filter elements in a pratically uniform manner over the whole length of the filter, and in that, on each filter element (12), the said filter has means of abutment (19, 20) designed to rest against an adjacent filter element (12) under the effect of a pressure exerted on these elements when the filter is in the filtration mode, on the one hand to ensure that the thickness of the slot between the said elements, in its narrowest part, is exactly as chosen, and on the other hand to prevent these elements from vibrating, in this mode, under the effect of the flow of the liquid between them, these abutments being out of contact with the adjacent filter element in the cleaning mode, thereby allowing these elements to vibrate in order to improve cleaning. |
