Centrifuge "beach" area

[pvcguy]

Has anyone any experience with centrifuges for the separation of PVC slurry and water? We are trying to find out what the design basis is for the “beach” area of the bowl. We have been quoted 15/3 or 15/5-degree angles for this area. Nobody has been able to explain what the advantage is for either of these angles. Any information would be helpful.

 

[CARF]

First some links:

A good book:

http://www.fetchbook.info/Separations_by_Centrifugal_Phenomena.html

A good manufacturer:

http://www.westfalia-separator.com/en/index.htm

This is what I learned from these guys: If your product under mechanical pressure of the auger/scroll is "squeezes" out (like a sponge) a steep angle will squeeze out more liquid out of the solids. This may happen with fruit fibers / juice separation.

Some product are insensitive for squeezing like water sand mixtures.

So the question for you is what happens with PVC slurry and water when being pushed up the beach?

Of course a steeper beach will generate more torque on the scroll.

Hope this helps,
CARF

 

[ischgl99]

When I worked for Westfalia Separator, I worked with a guy doing some research on PVC separation, but that was many years ago. I don't recall seeing the beach angle being refered as 15/5 or 15/3. Did you mean 15.5 and 15.3? If so, that is not much of a difference.

For the beach angle, basically for noncompressible solids like in PVC, a steep beach will work best with a low pond depth so that the water can drain back to the centrate end. The choice of what angle to use is based on testing as to which worked best. Each product is a little different and one manufacturer might have found one angle works best in their machine while another found a different angle. I wouldn't be too concerned about the beach angle, make your specification with performance garrantees and hold them to it.

Mike Bensema

http://www.dutchmenservices.com