GB803215A - Improved method and apparatus for pressing liquid out of vegetable substances - Google Patents

Abstract

803,215. Presses for separating liquids from solids. LANDSVERK A.B. Nov. 6, 1956 [Nov. 23, 1955], No. 33917/56. Class 46. [Also in Group VI] In pressing liquid out of, e.g., a vegetable substance during its passage through press chambers provided between a spindle with flights and a surrounding perforate screen wall, the chambers being separated by intermediate resistors, the press is characterized in that the numerical quantity Q obtained by multiplying the volume of the first press chamber by the number of flights in the chamber and dividing by the screen area of the chamber is at least four times as great as the corresponding numerical quantity for the last chamber, and furthermore the ratio of these quantities for the first two chambers is greater than the corresponding ratio for the last two chambers. Moist material, e.g., beet pulp, is fed by a worm 16, Fig. 1, into a hopper 12 where it is stirred by members 11 on an extension 10 of a screw spindle 1 prior to passing into the space between the spindle and a cylindrical screen jacket 3. The space is partially divided into four press chambers, P1.. P4, by resistors in the form of short guide plates 8 extending between sets of screw blades S 1 . . S 4 . The space between the screen jacket 3 and an outer casing 4 is divided by partitions 2 into three compartments each having a juice outlet 5, 6 or 7. The pulp is discharged through openings 26, Fig. 1, in a rotatable valve disc 24, Fig. 3, and thence through corresponding openings 27 in a supporting disc 23. By adjustment of the valve the pressure in the final press chamber P4 may be made to exceed 2.5 atmospheres. In Fig. 6 six press chambers are provided, of progressivelydiminishing height, and there are two screw blades on the spindle 1 in each chamber. The volume of each chamber is represented as a hatched rectangle in Fig. 7 and the ratio V/A as a horizontal distance from the vertical axis through the figure 0. In Fig. 8 (not shown) there are eight press chambers all the same height with two screw blades in each of chambers P2 and P3 and four in each of the remainder; the spindle is cylindrical in chamber P1 and in most of chamber P2, and there is an abrupt change of cone angle in chamber P4. The quantity Q for the first press chamber is preferably at least twice as great as that for the second press chamber and at least three times as great as that for the third press chamber. The ratio between the quantities Q for any two successive chambers is preferably greater than the ratio between the corresponding quantities for any two subsequent and successive chambers. The spindle may be perforated and used for drainage. Specification 803,216 is referred to.