GB1394237A - Apparatus for pumping highly viscous materials - Google Patents

Abstract

1394237 Feeding moulding machine DOW CHEMICAL CO 14 June 1972 27883/72 Heading B5A [Also in Divisions F1 and B8] A roll pump for pumping viscous material through an opening in means for containing the material comprises a stationary feed member mounted within the container and co-operating with a body such that rotation of the latter causes the feed member to scrape viscous material form the body and force it through the opening. In one arrangement the pump is mounted at the base of a polymer devolatilizer 5 and comprises a stationary feed member 17 formed by a double right helix, the flights 29, 30 of which have downwardly extending peripheral flanges 25. Member 17 co-operates with a smooth cylindrical shaft 19 such that when driving means 12 rotates the latter polymer is scraped from the shaft surface and forced through opening 8 into a screw transfer device 11 forming a continuation of the shaft and thence through outlet 13, e.g. to a pelletizer, extruder or compression-moulding apparatus. In a modification (Fig. 2, not shown) the stationary feed member is a single-turn right helix (17a) having a partially enclosing cylindrical wall (31). In another arrangement (Figs. 3, 3A, not shown) the feed member is formed by four angularly spaced inclined scoop-like scraping pieces (17b). The smooth cylindrical shaft 19 may be replaced by one having a square, triangular or hexagonal shape with a smooth or roughened surface. The surface of the stationary feed member may be smooth or roughened and may be coated with p.t.f.e.