| 摘要 |
1, 34,174. Filters for liquids. WALKER MANUFACTURING CO. April 3, 1963 [April 6, 1962], No. 13174/63. Heading B1D. A filter element comprises a porous body formed of substantially uniform diameter resincoated rayon fibres, said fibres being disposed randomly and being moulded under heat and pressure to a rigid shape, the resin acting as a binding agent. A filter cartridge 1 has a perforated outer shell 3, and a perforated inner shell 5 between which lies the filter medium 9 and a fabric sleeve 7. A cap 11 seals the top of the filter whereas annular cap 13 leaves shell 5 open. Oil flows from outside to inside, via filter 17 and filter 21 of the above-defined type. Filter 17 comprises a material such as waste cotton, whereas filter medium 21 is preferably composed of viscous rayon fibres of 60-70Á in diameter which are crimped and coated with a resin bonding agent, e.g. a phenolformaldehyde resin, and then moulded under pressure and temperature to form a rigid structure. The shape of element 21 is such that its inner surface area is equal to its outer surface area, and this is achieved by tapering the unit at top and bottom. The element itself is attached to the base of cap 11 so that the whole may be removed as a unit. In a further embodiment, uniform porosity of the element is obtained by forcing an air stream containing short fine fibres through the element. The fibres deposit themselves in regions of high flow and produce uniformity of porosity, themselves acting as a filter medium. The fibres may if desired be resin coated so as to stick and can be moulded into place. They may also be of rayon but may be selected and treated to absorb, adsorb and/ or strain out impurities |
