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[Star_Enigma]

Hi all,

 

I'm working on a project to reduce recycle rates on vibrating mesh screens for phosphate rock slurry.  The rock grind is good enough such that only 11% of the rock is bigger than the screen mesh size.  The screen over product is sent back to the ball mills and our screens are designed to have a 30% recycle rate.  Lately however, we have been getting higher recycle rates.  Upon initial inspection, the slurry has dewatered enough while still on the screen as to form a cake over 1/4 to 1/3 of the screen area.  This has effectively blinded a large portion of the screen.  Screen sprays have been used in the past to help with this, but have not been found to reduce recycle rates considerably.

 

One of the things I would like to look at is the angle of the mesh screen.  Currently it is at about a 45 degree angle.  I would like to figure out the angle to increase the screen to such that the slurry does not dewater so much that the weight of the wet cake will slide off the screen.  I don't know how to handle a laminar flow momentum balance with slurry passing through the screen as product.  I would appreciate any advice on how to handle this from a calculation standpoint.

Edited by Star_Enigma, 31 May 2013 - 07:41 PM.