Patent GB-1090573-A (GB)
Title: Improvements in or relating to separating apparatus
IPC: B04B5/04
Filed: 1965-01-04
Abstract: 1,090,573. Centrifugal separators; gravity settling. H, P. O. UNGER. Jan. 4, 1965 [Jan. 3, 1964], No. 297/65. Headings BID and B2P. A mixture of liquids of different densities or a liquid suspension of particles of different densities is allowed or caused to stratify into fractions of different densities and the stratified mixture or suspension is subjected to a displacing force so as to channel the fractions successively into or through containers arranged in series, each fraction being collected in a separate container of the series. In Fig. 3, interconnected containers 58-61 made of plastic material are housed in pockets peripherally located in the head of a centrifuge. Liquid suspension is introduced into the container 58 and, as the centrifuge is rotated, it separates into a number of fractions of decreasing density radially inwardly due to the action of centrifugal force. When the container 58 is filled, a displacing force produced by further introduction of the suspension causes the fraction of lowest density to be displaced via the interconnecting tubing into the container 59. Continued supply of the suspension will cause the next denser fraction to enter the container 59 and the fraction of lowest density to be displaced thereby into the container 60 and so on. Filling bodies 62, 63 may be provided in the container receiving pockets to vary their volume. In another embodiment, Fig. 2 (not shown), the displacing force is produced by fluid supplied via a pipe (57) connected to the bottom of the first container (50) of the series. The fluid may be the same as the suspension being fractionated or as the fraction of highest density or it may be a different fluid which may have a density higher than that of the fraction of highest density. In another embodiment, Fig. 4 (not shown) each container may be provided with its own inlet tube or passage for the introduction of the displacing fluid, e.g. tubes (64, 65, 66). A number of filling bodies (67-69) may be introduced in one and the same pocket. In a modification of Fig. 4, Fig. 5 (not shown), a collapsible bag (70) is located in the container-receiving pocket and displacement of the fractions from the bag is effected by introducing the displacing fluid, e.g. gas, into the base of the pocket so as to cause reduction in volume of the bag. Each pocket may also be provided with its own displacing fluid inlet tube. In another arrangement, the container receiving pockets are filled with discriminator liquids of successively decreasing densities such that in a given pocket the density of the discriminator liquid corresponds to the lower density of the fraction to be isolated in the corresponding container. Where a mixture or suspension of higher density than the discriminator liquid is introduced into the container, it will displace any mixture or suspension of lower density than the surrounding discriminator liquid to the next container. Different shapes and construction of containers are disclosed in Figs. 9 and 10g (not shown). Devices for introducing the suspension or mixture or the displacing fluid into the pockets or containers are disclosed in Figs. 6-8 and 11 and 12 (not shown). In a further embodiment, Figs. 14 and 15 (not shown), the container receiving pockets are disposed in radially spaced rows (108-111), the pockets being formed by removable partitions or fixed partitions (112) with removable thresholds (113, 114). Other constructions of centrifuges include a hollow cylindrical bowl having radially inwardly protruding beads to define pockets for receiving containers, or a bowl having a smooth inside with clamps for holding containers or bags. In a gravity-type separator, Fig. 1, a carrier body 30 is provided with pockets 31-35 covered by a common lid 36 and housing containers 37-41 made of pastic material and interconnected by tubes, e.g. 43. The suspension to be fractionated is introduced into the container 37 through an inlet tube 42 and displacing fluid is introduced through tubes 45-48 into the pockets to reduce the volume of the respective containers for the transfer of the fractions from one container to the other. Alternatively, the displacing fluid may be introduced directly into the containers.