GB869946A - Method and apparatus for screening pulp - Google Patents

Abstract

869,946. Filters; centrifugal strainer separators. IMPROVED MACHINERY Inc. Aug. 12, 1959 [July 2, 1959], No. 27557/59. Class 46. Pulp to be strained is introduced through a volute inlet 14, Fig. 1, and past a stator 16 for converting inlet velocity-head into a swirling action, to a casing 10. Within the casing is a fixed cylindrical screen 12 and rotating within the screen (in a clockwise direction, looking from left to right in Fig. 1) is a rotor, Fig. 2, consisting of a solid baffle 28 carrying blades 30 which are also supported by rings 32. The blades are backswept a few degrees from the direction of rotation, Fig. 3 (not shown), and are also helicoidally pitched, but in opposite directions on opposite sides of the baffle, as shown in Fig. 2. The optimum performance of the apparatus for any given stock depends upon the pitch- or retarding- angle of the portions 30<SP>1</SP> of the blades. Since these portions are cantilevers they may be adjusted where the apparatus is being used. The number of blades, speed of rotation, and size and number of perforations depend on the nature of the stock. The entrance to the rejects outlet 26 is kept clear by paddles 34. Specifications 852,994 and 853,644 are referred to.