Internal circulation type centrifugal extractor

A centrifugal extractor for use in extraction of first and second liquid phases, comprising:

• a cylindrical casing having a first phase inlet and a second phase inlet in a lower part thereof, a fist phase outlet and a second phase outlet in an upper part thereof, an inner wall, and a bottom wall;
• a cylindrical rotor rotatably mounted in said casing for high speed rotation, said cylindrical rotor being spaced from said inner wall of said casing and from said bottom wall of said casing to form gaps therebetween, said gap between said rotor and said bottom wall of said casing constituting a mixing chamber, and a supply port being formed in a bottom of said rotor for supplying a mixture of the first and second phases into said rotor from said mixing chamber;
• wherein a first phase draw port and a second phase draw port are formed in an upper part of said rotor at positions corresponding to positions of said first phase outlet and said second phase outlet, respectively, of said casing for directing the first and second phases flowing from inside said rotor toward said first and second phase outlets, respectively;
• wherein a first phase weir and a second phase weir are mounted in said rotor for guiding the first phase and the second phase, separated from one another by centrifugal force inside said rotor, to said first phase draw port and said second phase draw port, respectively;
• and
• wherein a reflux cover is fitted to said upper part of said rotor to encompass an outer periphery of said rotor and maintain a space between said outer periphery of said rotor and said reflux cover, said reflux cover constituting a reflux means for causing one of the first and second phases flowing out through its respective draw port toward its respective outlet to be partially diverted to said mixing chamber.