I have got the date for cyclonic separation back to at least 1934 http://www.buellrefinery.com/ http://www.buellrefinery.com/ but as it says on Wikipedia Dyso

I have got the date for cyclonic separation back to at least 1934 http://www.buellrefinery.com/ http://www.buellrefinery.com/ but as it says on Wikipedia Dyson has himself said he didn't invent cyclonic separation http://en.wikipedia.org/wiki/Dyson_(company) http://en.wikipedia.org/wiki/Dyson_(company) "During a visit to a local sawmill, Dyson noticed how the sawdust was removed from the air by large industrial cyclones. He conjectured the same principle might work, on a smaller scale, in a vacuum cleaner."