| 摘要 |
828,361. Filters. DU PONT DE NEMOURS & CO., E. I. March 28, 1957 [April 16, 1956], No. 10220/57. Class 46. [Also in Group V] Apparatus for concentrating and feeding a liquid slurry of polymeric particles into a screw extruder comprises a tubular screen 2, one end of which fits the inlet port 4 of the extruder 8, a casing 3 enclosing and spaced apart from the screen, sealing means at the open ends of the screen to prevent communication from the screen interior to the surrounding annular space except through the screen perforations, means for introducing liquid slurry into the end of the screen remote from the screw extruder inlet port, and means for collecting and removing liquid from the annular space. In particular the apparatus is for obtaining from an aqueous slurry of polyvinyl butyral particles, a mass of the plastic sufficiently dewatered for it to form a suitable feed material for a screw extruder and in its preferred form there is provided within the tubular screen 2 a screw 1 to convey the slurry, which is fed continuously from pipe 10 to the inside of the top of the tubular screen 2, liquid passing through the screen into the annular space 6 while the solid particles are propelled forward and concentrated. In another form of the invention, screw conveyer 1 is dispensed with and screen 2 is frustoconical in shape and encircled by a number of skirts in the form of hollow truncated cones. By this means the water as it runs down the outside surface of the screen is diverted away by the skirts thereby freeing the screen surface for the passage of more water from inside the screen. |
