| 摘要 |
1,135,911. Making filters. ETABS POMPES GUINARD. 9 Jan., 1967 [25 Jan., 1966; 23 Nov., 1966], No. 1164/67. Heading B3A. [Also in Division B1] The filtering screen of a centrifugal strainer comprises a metal sheet element of frustoconical shape, having rows of slots 16 and external projections 16B which space the element from the external supporting basket 19. As shown, the projections comprise ridges extending between parallel rows of slots, and run obliquely to the bars of basket 19 to minimize areas of contact (19M), (Fig. 12, not shown). Material is moved up the screen by a differentially rotating screw 18, or the drum may widen upwards (Fig. 15, not shown). In Fig. 14, (not shown), the screen has internally projecting ridges also, which serve to accelerate or retard the motion of material up the screen. Slots 16 are produced by punching or by successive punching and swaging operations, and the sheets are subsequently stamped or rolled to reduce their thickness and produce slots of uniform or converging section (Figs. 1, 2, not shown). The projections 16B are produced between rows of slots by stamping only the slotted parts of the sheet (Figs. 3, 4, 5, not shown). Optionally projections may be produced between slots also, using a profiled stamp (Figs. 6, 7, not shown). Similar results may be achieved by rolling, using rollers with axial or annular grooves under which the sheet is passed (Figs. 17 to 19, not shown). Figs. 20, 21 (not shown) illustrate an element formed by electrolysis, with staggered slots and projecting bosses therebetween. Slots may be polished by jets of abrasive before and/or after stamping/rolling. |
