Study of spheres in conduit

[engineeringforum]

Looking for information on the study of balls/spheres traveling together through confined spaces such as tubes, pipes, boxes etc. Recently I was tasked with designing a hopper style system for plastic coated metallic spheres that push each other through multiple tubes at high rates of speed. All tubes intersect with only one output. Balls are getting wedged where the tubes intersect and we have had limited success with different 'converging geometries'. Hopefully there has been some kind of research on the topic. If anyone knows of a data source, I'd be very appreciative.

Thank you.

 

[btrueblood]

You might be able to find something similar in journals covering two-phase or solid conveying flows. Usually, though, solid conveying is done with diffuse solids (i.e. much more air than solid) and at velocities where the solids remain suspended/dispersed.

What you are describing is a compacted solid. Intuitively, any contraction of area at the convergence (with no other mechanical "sorting" device) will cause one or more of the ball "streams" to jam.

 

[Denial]

When you find a solution, you'll be able to make a fortune applying it to cars on freeways.

 

[rconner]

I have no experience in your application; however, it would be interesting to know if mounting a sufficiently sized vibrator on the convergence fitting etc. might keep things moving (of course only if the vibration doesn't cause some other problem). [Don't know how to apply this principle to an impromtu parking lot on an interste highway, as shaking things upe.g. with a little road rage etc. doesn't apper to do much good!]

 

[amorrison]

In addition to rconner's vibrator suggest "rubber" hose connection that could be "whacked" when necessary.
Constant external applied motion (violent or gentle sinusoidal) should alo be considered.

 

[Cockroach]

You may find some of the studies in oilfield related applications off the Halliburton, Schlumberger or Baker websites. Typically we are bummed out over "ball drops" for hydraulic activated sealing.

i.e. drop of an Ertalyte ball from surface into a tubing string of specified annulus, water table is set for a prescribed distance below.

There are several papers in the community which may be of help, if you need a few, write and I can pull them to send your way.

Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada