Patent ID: 8758210

Claim:
An apparatus ( 10 ) for performing a centrifugal field flow fractionation comprising: a shaft ( 61 ) having a central axis and conduits ( 54 a /b) along said central axis for sample fluid to pass therethrough, the shaft ( 61 ) having an upstream shaft end for the sample fluid to enter into and a downstream shaft end for the sample fluid to exit from the shaft ( 61 ), the shaft ( 61 ) carrying a rotor ( 10 a ) between the upstream and the downstream shaft ends and being rotatably supported in bearing blocks ( 24 a /b) at both said shaft ends so that the rotor ( 10 a ) and the shaft ( 61 ) are rotatable about the axis, a field flow fractionation channel ( 13 ) on the rotor ( 10 a ), the field flow fractionation channel ( 13 ) being configured to let the sample fluid pass therethrough and having an upstream channel end for the sample fluid to enter into the channel and a downstream channel end for the sample fluid to exit from the channel ( 13 ), the upstream channel end being connectable in a fluid-tight manner to a conduit ( 54 a ) at the upstream shaft end and the downstream channel end being connectable in a fluid-tight manner to a conduit ( 54 b ) at the downstream shaft end, an upstream end cap ( 28 a ) which fits over the upstream shaft end and can be attached to the bearing block ( 24 a ) at the upstream shaft end and a downstream end cap ( 28 b ) which fits over the downstream shaft end and can be attached to the bearing block ( 24 b ) at the downstream shaft end, the upstream cap end ( 28 a ) and the downstream end cap ( 28 b ) each having a terminal ( 40 a /b) for connection to a line for the sample fluid, the upstream end cap ( 28 a ) and the downstream end cap ( 28 b ) each having a further terminal ( 44 a /b) for connection to a line for flushing fluid, the upstream end cap ( 28 a ) and the downstream end cap ( 28 b ) each having a second recess ( 37 a /b) and a first recess ( 39 a /b), each of the second recesses ( 37 a /b) being for accommodation of a second radial rotary shaft seal ( 36 a /b) for sealing the end cap ( 28 a /b) against the shaft ( 61 ) and each of the first recesses ( 39 a /b) being for accommodation of a first radial rotary shaft seal ( 38 a /b) for sealing the end cap ( 28 a /b) against the shaft ( 61 ), each of the second recesses ( 37 a /b) on one side of its second radial rotary shaft seal ( 36 a /b) being in fluid communication with the terminal ( 40 a /b) for connection to the sample fluid line and on the other side of its second radial rotary shaft seal ( 36 a /b) being in fluid communication with the terminal ( 40 a /b) for connection to the flushing fluid line, and each of the first recesses ( 39 a /b) on one side of its first radial rotary shaft seal ( 38 a /b) being in fluid communication with the terminal ( 44 a /b) for connection to the flushing fluid line, so that both sides of the second radial rotary shaft seals ( 36 a /b) are subjected to fluids.