> Dennis Morefield
> Anyone out there know the proper way to calculate centrifical force?
 
The optimum speed your extractor depends on the type and diameter of
your unit.
 
Centrifugal force for an extractor can be calculated with the formula
f=mv²/r where f = force in newtons, m=mass in kgs, v=velocity in
metres/second, and r= radius in metres.
 
In practice an extractor with a diameter of 1.2 metres (from frame
centre to frame centre) at 150rpm will develop 14.8 times the force of
gravity and this works for semi radial extractors (one speed only).
If these are full depths, there will be around 12.3 Gs on the bottom
bars and 17.3 Gs on the top bars.  The difference in centrifugal force
between top and bottom bars is greater in smaller extractors.
 
The following implications are also important::
 
2X RPM and force goes up 4X.
3X RPM and force goes up 9X.
I.e. RPM has an exponential effect on force.
 
2X diamter and force goes up 2X.
3X diameter and force goes up 3X.
I.e. Increases in Diameter have a linear effect on force.
 
It's important to get the RPM right!
 
Peter Bray
 
Airborne Honey Ltd., PO Box 28, Leeston, New Zealand
Fax 64-3-324-3236,  Phone 64-3-324-3569  [log in to unmask]
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