GB869312A - Treating fibrous material - Google Patents

Abstract

869,312. Screening apparatus. JOHNS-MANVILLE CORPORATION. April 20, 1959 [April 23, 1958], No. 13361/59. Class 117 Dust or other foreign matter is removed from fibrous material in apparatus comprising a housing 10, connected by ducts 11, 12 to a vacuum creating source, and having openings in its end walls for the passage of endless screens 17, 35 between which the material to be treated is carried, and subjected alternately to upwardly and downwardly directed gas streams from staggered groups of nozzles 57, 62 during its passage through the housing. Thus the dust &c., is forced through the screens and carried away from the housing through the exhaust ducts 11, 12. Foam rubber strips 26, 27, 28, Fig. 3, are attached to the lower screen 17, and untreated material is fed on to it from a hopper 30. Rollers 40, 43 extend the full width of the screens and are adjustably mounted so that the co-operating runs of the screens are urged together whereby the strips 26, 27, 28 are compressed slightly to form separate compartments 29. Tensioning rolls 48, 45 are provided for the upper and lower screens respectively. A power source 23 drives the lower screen, and the upper one is moved by frictional engagement with the rubber strips. The nozzles 57, 62 extend respectively from lower and upper headers 55, 60 respectively, connected to blowers. An aspirator 65 removes the cleaned fibres from the lower screen, and a suction box 68 cleans the inner surface thereof.