GB1259874A - Centrifugal separator - Google Patents

Abstract

1,259,874. Centrifugal separators. MITSUBISHI JUKOGYO K.K. 13 Feb., 1969 [15 Feb., 1968; 18 June, 1968], No. 7927/69. Heading B2P. [Also in Division F1] A centrifugal separator for separating constituents of liquid or gaseous mixtures of little difference in specific gravity, e.g. isotopes U 235 and U 238 of natural uranium, comprises a rotor which is rotatably supported in a casing and which has a plurality of independent separating chambers each in the form of an elongate hollow in the rotor at a position remote from the axis of rotation and substantially parallel to the axis of rotation, each chamber having an opening for supplying the mixture to be treated, an opening for discharging a separated light fraction and an opening for discharging a separated heavy fraction, the latter opening being at a greater distance from the axis of rotation than the other two openings, and the rotor having passages which communicate the openings with the outside of the separator. In Figure 1, the mixture to be treated is fed through an inlet port 8 in the casing 1 and flows through a passage 12" in the casing, a centre hole 12' in the driving shaft 4 and passages 12, Figure 2(a), in the rotor 2 into separating chambers 9 in which the mixture is separated. The light fraction is extracted through passages 13 in the rotor, a centre hole 13' in the shaft 4, a passage 13" in the casing and an outlet port 10 therein. The heavy fraction is removed through outlet ports 15, passages 14, an annular passage 14', a passage 14" and an outlet port 11. The rotor section may be elliptical, as shown, circular or approximately square, Figures 3 and 4 (not shown). L-section seals, as shown, or labyrinth seals are provided at 5, 5', 5" and 6 and labyrinth seals at 16. Exits 17 are provided for removing fluid leaking past the seals to the outside. An exhaust port 18 connected to a vacuum pump is formed in the casing 1 for drawing off air in the space between the rotor and the casing to reduce frictional heat developed during rotation of the rotor. In Figure 5, the centrifugal separator rotor 101" is integral with a driving turbine rotor 101' both rotors being integral with a common shaft 101"' and supported in a common casing 102. The turbine rotor comprises a turbine impeller wheel 105 which faces a group of nozzles 106 connected with a chamber 107 provided with a port 108 for the supply of steam or other driving fluid. The space 109 between the rotors and the casing serves as an exhaust chamber for the turbine and is under vacuum being connected via a port 110 to a condenser. The separator rotor 101" is of elliptical cross-section, Figure 8 (not shown). The mixture to be separated is supplied through a port 112 and the light and heavy fractions are discharged through ports 117 and 122 respectively. Labyrinth seals supplied with sealing steam from ports 125, 126 are provided at 123, 124. Further labyrinth seals and exits for fluid leaking therefrom are provided at 127 and 128 respectively.