Ultracentrifuge rotor

Claim 2

An ultracentrifugation process which comprises spinning material which is to be separated about a spinning axis, permitting heavier particles to sediment to a plurality of regions in the material, in which the regions are annular and concentric with the spinning axis and the different regions are at different radial distances from the spinning axis, constraining such particles to slide in thin layers directed at angles between 20* and 70* to the spinning axis outwardly, causing the particles in all the thin layers to all slide into an annular layer which is orientated at 90* to the spinning axis the particles joining to form a narrow-width stream in this annular layer, to stream away from the spinning axis and to collect in an outermost annular collection region, in which the rotational speed of spinning is selected at a value which satisfies the condition that a number, N, computed from the formula

Claim 3

An ultracentrifugation process as claimed in claim 1, which is performed as a batch process, comprising preliminarily containerizing a material to be separated and applying a rotational acceleration to the material and terminally decelerating the spinning material at a means for deceleration while isolating the rotational backwash of unsedimented material substantially from the sedimented material by an intervening barrier, bringing the material to standstill, removing the unsedimented material, removing the intervening backwash barrier and taking out the sedimented material.

Claim 4

An ultracentrifuge rotor which comprises an annular outer chamber defined by walls which are disposed equidistantly about an axis of rotation, which has a plurality of radially spaced annular vanes in the chamber presenting inwardly directed surfaces which are concentric with the axis of rotation and which are inclined at an angle between 20* and 70* to the axis of rotation, in which every vane terminates in a free edge further removed from the axis of rotation than remaining parts of the vane, every vane has an edge which is closer to the axis of rotation and which is contiguous with the wall defining the chamber and in which every vane is wholly imperforated, in which every vane free edge is aligned on an imaginary plane normal to the axis of rotation, a narrow passage in the rotor defined between said vane free edges and a surface of the rotor on a plane substantially normal to the axis of rotation, in which the narrow passage is terminated by an annular sediment collection groove located outwardly of the vanes, concentric therewith and formed by structure which is fixed to the walls forming the inner and outer chambers and in which means for retaining the collected sediment against backwash is located at a sole annular entrance to the annular collection groove, in which the annular anti-backwash structure is concentric with the axis of rotation, is removable from the entrance to the collection groove and nearly closes the entrance to the groove so that at rotational speeds which cause sedimenting the annular structure permits sedimenting material to pass into the collection groove while during deceleration it resists backwashing.

Claim 5

An ultracentrifuge rotor which comprises an annular outer chamber defined by walls which are disposed equidistantly about an axis of rotation, which has a plurality of radially spaced annular vanes in the chamber presenting inwardly directed surfaces which are concentric with the axis of rotation and which are inclined at an angle between 20* and 70* to the axis of rotation, in which every vane terminates in a free edge further removed from the axis of rotation than remaining parts of the vane, every vane has an edge which is closer to the axis of rotation and which is contiguous with the wall defining the chamber and in which every vane is wholly imperforated, in which every vane free edge is aligned on an imaginary plane normal to the axis of rotation, a narrow passage in the rotor defined between said vane free edges and a surface of the rotor on a plane substantially normal to the axis of rotation, in which the narrow passage is terminated by an annular sediment collection groove located outwardly of the vanes, concentric therewith and formed by structure which is fixed to the walls forming the inner and outer chambers and in which means for retaining the collected sediment against backwash is located at a sole annular entrance to the annular collection groove, in which the annular anti-backwash structure is concentric with the axis of rotation, is removable from the entrance to the collection groove and nearly closes the entrance to the groove so that at rotational speeds which cause sedimenting the annular structure permits sedimenting material to pass into the collection groove while during deceleration it resists backwashing.

Claim 6

An ultracentrifuge rotor as claimed in claim 3, in which the means for retaining the collected sediment against backwash comprises a roughened ring whereby through passages is provided.

Claim 7

An ultracentrifuge rotor as claimed in claim 3, in which the annular structure comprises a ring of flexible material having a lip which at standstill closes the groove but which is of suitable cross section and flexibility so that at certain rotational velocities the entrance to the groove is opened as a result of flexing of the lip under centrifugal reaction.

Claim 8

An ultracentrifuge rotor as claimed in claim 5, in which the lip has vent holes provided in it.

Claim 9

An ultracentrifuge rotor as claimed in claim 3 which comprises an annular inner chamber disposed equidistantly around the axis of rotation disposed inwardly of the outer chamber and concentric with it the inner chamber having a wall which forms an inwardly directed sedimentation surface in which the inwardly directed sedimentation surface of the inner chamber is at all points equidistant from and parallel to the axis of rotation in which a passage passes through the wall forming the inwardly directed surface, the passage having closure means adapted to be self-opening upon centrifugal reaction of a closure member of the closure means exceeding a predetermined value by reason of an increase to a predetermined rotational speed of the rotor, in which the passage leads to the outer chamber.