Patent GB-1421453-A (GB)
Title: Apparatus for extruding flowable materials
IPC: B29C48/465
Filed: 1973-01-12
Abstract: 1421453 Rotary drum extruder RIETERWERKE DIPL-ING WALTER HANDLE GmbH 12 Jan 1973 [14 Jan 1972 3 May 1972] 1814/73 Heading B5A An extruder for slurries, cellulose, meat, or clay materials, comprises a rotary conveying drum having circumferential grooves within which the material is conveyed between an extruder inlet 11, Fig. 2, and a location at which the material is removed, by means 15, into an extrusion outlet 12, the grooves being wider at the control region of the drum than at its ends. In the Fig. 2 embodiment, the impeller is a single drum 10, in a housing 8, to which drum the material is fed, under vacuum and from the multiple extrusion orifices 51 of a twin screw extruder 2, by the cylindrical surface of a feed roller 14 with which co-operates a scraper 17 adjustable by means 18. The means 15 comprises a scraper comb having teeth 16 adjustably projecting into the grooves, and replaceably clamped between spacers by a tie rod 33. The grooves may be recessed into a cylindrical drum surface, but are preferably defined, Fig. 3, between annular continuous, or 90 degree segmented rings 13 which are of a progressively decreasing spacing apart towards the drum ends. The rings 13 are spaced apart by continuous or segmented spacers 21 between which rings 13 are replaceably clamped, by tie rods 23, around a cylinder 20 on which wedges 22 key the rings 13 and spacers 21 against rotation. At each of its edges, the drum 10 is in sealed engagement at an annular groove 26 with an annular flange 27 of the housing 8, material passing the seal being returned to the inlet from a groove 28, via a scraper 30, 29 and opening 31 of flange 27. The housing 8 is provided with an interchangeable part 34 including the outlet 12 and providing access to the means 15; is provided with a replaceable wear lining 32; and at one side is closed by a plate 35, carrying a bearing 36 of the shaft 37 of drum 10, and which is removable to permit a device 38, Fig. 4, to remove the drum 10 from the housing 8. For this purpose, the housing of the device 38 is bolted at 44 to the drum 10, and at 49 by a spindle 46 to the shaft 37, and the device 38 acts to withdraw the drum 10 from the housing 8 and around its shaft 37, by a nut drive along the spindle 46 as the housing of the device 38 moves on rollers 50 along vertically adjustable rails 40. Tilting of device 38 during withdrawal is prevented by the rollers 50 remote from the housing 8, Fig. 1 (not shown) engaging laterally within the rails 40 which are of laterally open channel configuration. In the Fig. 5 embodiment (not shown), where a feed 14 is not provided, a pair of parallel drums are provided in the same housing, each rotating in opposite directions, at the same or different speeds, and delivering, via a similar means 15, each to a similar outlet. In the Fig. 6 embodiment, roller and a conveying drum 214, 210 are provided, as well as a further conveying drum which rotates in the same direction as and engages in the grooves of roller 210 to remove material therefrom which is removed to the outlet 212 by a scraper comb 215a.