| 摘要 |
1,033,669. Screw conveyer. H. J. ZIMMER. Dec. 7, 1962 [Dec. 7, 1961], No. 46293/62. Heading B8A. [Also in Division B1] A conveyer suitable for carrying out a chemical reaction (see Division B1) comprises at least two enmeshing worms supported horizontally in a container, the lower part of which closely surrounds the worms, an inlet and an outlet; wherein (a) the worms are of the same pitch, of the same hand and the relative phases of which are such that when rotated there is at least some interengagement to effect mutual self-cleaning, (b) the flanks of the worms have radii of curvature equal to the distance between the axes of adjacent worms (f, Fig. 8) and (c) the centre of curvature of each flank is at a distance from the axis equal to the greatest radial dimension of the adjacent worm (g, h, Fig. 8). As shown in Fig. 2, material is introduced through inlet 41 and removed from outlet 42 by means of a further conveyer screw 67 and a vacuum is maintained in the apparatus, being applied through the outlet 44. The worms are driven by motor 52 through suitable gearwheels (see Fig. 4, not shown). Heating jackets 46, 47 and 48 surround the chamber. The illustrated apparatus has three worms supported in a horizontal plane. The worms may be of various kinds, and may or may not be identical. Thus Figs. 5 and 6 illustrate identical worms, those in Fig. 5 being similar to that shown at 19 in Fig. 8 and those in Fig. 7 being similar to that shown at 20 in Fig. 8. Fig. 9 shows a pair of similar worms having a " negative " core radius, i.e. having the shape of spirally wound worms wrapped around a cylindrical space. In Figs. 10 and 11 there are shown worms in which, considering a cross-section of the worm, the surface of the worm lying on the outer periphery thereof is reduced in length so that phase displacement of the worms is possible. By intermittently producing such phase displacement, opposite sides of the worms may be scraped. This phase displacement may be performed by temporarily changing the relative speeds of rotation of the worms for a predetermined time, e.g. by temporarily halting the rotation of one of the worms. Alternatively, the phase displacement may be achieved by linearly displacing one of the worms. Fig. 2 shows an arrangement for achieving this linear displacement comprising a piston operating in a cylinder 64 having means 65, 66 for admitting fluid to opposite sides of said piston, the axis of the worm being such as to slide through the centre of the gear 54 whilst being forced to rotate therewith: the gear-wheel 54 itself is held against axial displacement. |
