Mechanical seal for centrifugal field-flow fractionation device

A centrifugal field-flow fractionation device comprising:

• an annular rotor that rotates about a rotational axis;
• a channel member that is provided in the rotor and has therein a channel for a liquid sample extending in an arc shape around the rotational axis, an inlet for the liquid sample to the channel, and an outlet for the liquid sample from the channel;
• a rotational shaft that rotates with the rotor and has a first channel in communication with the inlet or the outlet along the rotational axis;
• a fixing portion that is fixed in a state of facing the rotational shaft along the rotational axis and has a second channel in communication with the first channel along the rotational axis;
• and a mechanical seal that has a pair of seal rings in contact with each other and a biasing member, one of the seal rings being attached to the rotational shaft, and another of the seal rings being attached to the fixing portion, the biasing member biasing the pair of seal rings in a direction in which the pair of seal rings come into contact with each other wherein at least one of the rotational shaft and the fixing portion is formed with a branch path branched from a connection portion between the first channel and the second channel, and the pair of seal rings are biased in a direction in which the pair of seal rings come into contact with each other by a pressure received from a liquid sample flowing into the branch path.

A centrifugal field-flow fractionation device comprising:

• an annular rotor that rotates about a rotational axis;
• a channel member that is provided in the rotor and has therein a channel for a liquid sample extending in an arc shape around the rotational axis, an inlet for the liquid sample to the channel, and an outlet for the liquid sample from the channel;
• a rotational shaft that rotates with the rotor and has a first channel in communication with the inlet or the outlet along the rotational axis;
• a fixing portion that is fixed in a state of facing the rotational shaft along the rotational axis and has a second channel in communication with the first channel along the rotational axis;
• a mechanical seal that has a pair of seal rings in contact with each other and a biasing member, one of the seal rings being attached to the rotational shaft, and another of the seal rings being attached to the fixing portion, the biasing member biasing the pair of seal rings in a direction in which the pair of seal rings come into contact with each other a first pipe that is provided in the rotational shaft along the rotational axis and constitutes at least a part of the first channel;
• and a second pipe that is provided in the fixing portion along the rotational axis and constitutes at least a part of the second channel, wherein fops of the first pipe and the second pipe face each other in close proximity to each other at a position shifted toward the rotational shaft or the fixing portion with respect to a contact position of the pair of sea rings.