The archimedes screw is used very commonly to raise large volumes of 
water a short distance, say less than 50' feet. 2 uses are, to raise 
storm water flow over a level, or to a higher body of water, and in 
water (both storm and sanitary) treatment plants, to raise incoming 
water (including sanitary or industrial wastes) so that the remain 
process can be by gravity flow. They are very low maintenance, 2 
bearings to lube, a gearbox and motor that receives a no shock, uniform 
load.

On 7/8/2010 8:13 AM, Olin Lathrop wrote:
> RussellMc wrote:
>    
>> I'm well aware of Archimedes Screw BUT had thought that it was
>> relegated to the roles of developing country water lifting (often
>> manual), novelty toy and garden ornament. Apparently not.
>> Largest listed above is 12 foot in diameter.
>> It's in Texas :-).
>>      
> One of the cool things about the Archimedes Screw is that it works both ways
> with pretty much equal efficiency (which is quite high).
>
> A long time ago I mentally designed a heat engine loosely based on the
> concept of this screw.  It had exactly one rigid part and some fluid.  The
> single rigid part rotates when you make one end hotter than the other.  Of
> course a working version needs external parts to hold the single rotating
> part in place, let it rotate, remove power from it, apply heat to one end,
> cool to the other, etc.  But the engine itself is still just the one single
> rigid part plus a fluid.  The fluid is sealed in.
>
> I have never written this down before or made a drawing.  I did once try to
> explain it to someone else, but I think they didn't get it.  If I remember
> right, I had this idea in the mid 1990s.  I supposed I could write a SLIDE
> program to draw a 3D model of it, but so far I haven't.
>
> Anyone care to come up with this concept themselves?  If so, a brief
> discussion of efficiency would be interesting.  After thinking about it for
> a while, the losses, limitations, and how to overcome them were a little
> surprising to me.
>
>
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