GB938557A - Apparatus for impregnating wood chips and like cellular material - Google Patents

Abstract

<FORM:0938557/IV(a)/1> An apparatus for the impregnation of cellular plant stock e.g. wood-pulp, with liquids comprises a screw-press on the discharge end of which is an open-ended extension defining an <FORM:0938557/IV(a)/2> impregnation chamber into which liquid is introduced in a direction generally the same as that of the movement of the stock. In one embodiment the screwpress (Fig. 1) consists of a barrel 10 through which stock, fed in at 12, is continuously advanced under compression, in a partially fibrillated state, by means of worms and teeth on shaft 20. Certain sections of the barrel comprise cylindrical fittings 14, 15 and 16 supporting longitudinally spaced screen bars 17 and 18, which confine the stock within the press but permit the escape of air and liquids therefrom. A conical collar 39 provides a restricted passage 41 from the discharge end of the press into the impregnation chamber 42, defined by cylindrical extension 43, into which the plant stock, released from compression, passes in a dry, expanded and saturable condition. The impregnation of this moving column of stock is effected by cylindrical fitting 16 constructed as a liquid inlet ring (Fig. 3). Liquid from pipe or pipes 52 is injected via annular groove 51 into a plurality of circumferential openings 49, which discharge the liquid in streams forwardly of the ring and into the impregnation chamber in the same direction of movement of the stock therethrough. The ring may be modified to discharge the stream of liquid angularly into the impregnation chamber. The material under treatment is partially fibrillated by the press.