Material Compaction under Weight?

sinclasc
(not verified)
Posted in: , on 17. Feb. 2008 - 18:16

Hi all,

I'm doing a six sigma project about aging of powders. How does material compact in silos(and therefore change bulk density) over time and weight?

Are there any standard calculations for this?

Re: Material Compaction Under Weight?

Posted on 18. Feb. 2008 - 12:07

But you may also need to know what is the bulk density once the material has left the confines of the silo.

PS what's a quick snappy description of Six Sigma ??

sinclasc
(not verified)

Re: Material Compaction Under Weight?

Posted on 18. Feb. 2008 - 07:37

Hi designer,

Six sigma is a continuous improvement method aimed at reducing defects. In a nutshell, 6 sigma refers to 3.4 defects per million. In modern practise this generally involves using a structured method of statistical analysis to reduce problems.

Someone else might have a better answer than me though - I'm no expert!

Scott.


Originally posted by designer

But you may also need to know what is the bulk density once the material has left the confines of the silo.

PS what's a quick snappy description of Six Sigma ??

Bulk Density

Posted on 19. Feb. 2008 - 10:43

The settled state of a powder in a silo can be assessed from determining the overpressures at different depths by way of the Jansson equation and replicating the normal load in a compaction cell with a sample of product to establish the stored density. Time consolidation is mainly due to the escape of excess air loaded with the powder but may also be influenced by the deformation of soft particles.

The designers point about discharge condition is very important as the reduction in pressure and free fall conditions from the hopper or feeder outlet will usually produce a very dilated condition.