| 摘要 |
1,134,640. Sifting apparatus. SOUTHWESTERN ENG. CO. 29 Dec., 1965 [21 Jan., 1965], No. 55128/65. Heading B2H. A self cleaning screen structure for a vibratory separator comprises an upper separating screen I disposed in parallel relation with a lower supporting screen 2 of relatively greater mesh size and a number of cleaning elements 4 of uniform cross-section which occupy the major portion of the distance between the screens, have flat ends confronting the screens and are movable essentially axially between the screens. The screens are held parallel by a surrounding circular or rectangular rim. One or more circular separating screens may be mounted in a vibratory circular separator in which gyratory vibrations are imparted to the material disposed on the separating screen or screens and to the cleaning elements 4 by means of axially spaced and circumferentially displaced eccentric weights which rotate around the vertical axis of the screen or screens. Cleaning is by impact of the elements 4 on the underside of .the separating screen or screens due to the vertical component of vibration and by relative shearing action between the upper surfaces of the elements and the underside of the screen or screens due to the horizontal component of vibration. The cleaning elements 4 may be formed of ceramic material, plastic material or metal. They may be hollow cylinders. In cross-section, they may be triangular with convex sides (12), Fig. 5 (not shown) and with a central perforation ,(5): hexagonal with a central perforation. Fig. 6 (not shown); rosette-shaped with a number of perforations (17), Figs. 7 and 8 (not shown); cross-shaped Fig. 11 {not shown); or they may have a number of spokes (24), Fig. 12 (not shown), terminating in laterally directed, inter locking flanges which permit relative axial movement between the elements but prevent relative lateral or radial displacement. In another arrangement, Fig. 9 (not shown), the cleaning elements consist of a nesting set of rings (18 to 21). In operation, the smaller rings within and between the larger rings tend to orbit while the mass of rings as a whole is not subjected to gyratory movement. |
