Improvement in a filter unit

摘要

836,330. Filters. BENDIX AVIATION CORPORATION. June 10, 1958, No. 18541/58. Class 46. [Also in Group XXII] Unfiltered liquid entering at 5, Fig. 1, passes inwards through filter tubes 18 closed at the bottom by a disc 9 and surmounted at the top by an open-topped header 13 which rests on projections 19 on the tubes and has the upper ends of the tubes secured to its discportion 20. Filtrate leaves at 7. Each tube 18 is made by wrapping flattened wire around a cylindrical or conical mandrel, sintering the wire whilst in position, rolling or swaging the assembly to expand the winding slightly and compact the metal and finally withdrawing the mandrel. The swaging step may be followed by re-sintering. The wires may be coated initially with low-melting-point metal (e.g. copper) or alloy and sintered at a lower temperature. After sintering and removal of the mandrel the tube is processed to a finished form. In Fig. 2, the tubes 18 have their ends accommodated in holes provided in plates 26, 27. A cylinder 28 of the same material as the tubes extends between the plates, forming a chamber 29 about the tubes. Unfiltered liquid entering at 23 passes outwards through tubes 18 into chamber 29 and also inwards through cylinder 28 into chamber 29, whence filtrate passes out at 24. In Fig. 3 (not shown), the cylinder 28 is replaced by a plurality of layers of wire cloth which are under compression.