Simplified diagram of a gas centrifuge used for uranium isotope separation with a countercurrent circulation for increased separation.
<p>The current in this example is induced by the bottom (waste) scoop, and the product scoop is behind a baffle, which is attached to and rotates with the rotor, to prevent it setting up equal but opposite current. The uranium diffuses across the radius of the rotor, with <sup>238</sup>U migrating to the periphery and <sup>235</sup>U to the centre. The countercurrent then concentrates the <sup>238</sup>U to collect at the bottom (this is the waste or tail stream), and the <sup>235</sup>U to collect at the top (product stream).
</p><p>By baffling the bottom scoop, the inverse can be achieved (some diagrams show this instead), with <sup>235</sup>U collecting at the bottom. Some designs also use heating to drive the countercurrent.
</p>
The bellows are slightly flexible and allow the rotor to be operated at speeds that would otherwise be supercritical.
<a href="//commons.wikimedia.org/wiki/User:Inductiveload" title="User:Inductiveload">Inductiveload</a>
2020-01-12
<span class="int-own-work" lang="en">Own work</span>