Minimum velocity to keep particles in suspension
Minimum velocity to keep particles in suspension
(OP)
Hello,
I am trying to design a dilution system that would have a 1-10% particulate in fluid. This is spinning in a loop (vertical and horizontal components) and I am trying to have it fairly homogenized so that I can pull a representative sample.
I have used Stokes Law to find a terminal velocity for the fluid/particulate pair. My understanding is this is the point where the particles no longer accelerates but still moves at the calculated velocity. Do I simply need a velocity greater than the terminal velocity? How do I determine the velocity to circulate?
I am trying to design a dilution system that would have a 1-10% particulate in fluid. This is spinning in a loop (vertical and horizontal components) and I am trying to have it fairly homogenized so that I can pull a representative sample.
I have used Stokes Law to find a terminal velocity for the fluid/particulate pair. My understanding is this is the point where the particles no longer accelerates but still moves at the calculated velocity. Do I simply need a velocity greater than the terminal velocity? How do I determine the velocity to circulate?





RE: Minimum velocity to keep particles in suspension
http://www.engineeringtoolbox.com/slurry-transport...
RE: Minimum velocity to keep particles in suspension
Allocate substantial time.
Mike Halloran
Pembroke Pines, FL, USA
RE: Minimum velocity to keep particles in suspension
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: Minimum velocity to keep particles in suspension
"Whom the gods would destroy, they first make mad "
RE: Minimum velocity to keep particles in suspension
It seems that some people say to calculate Stokes and exceed the terminal velocity. Others seem to point to something much faster and more complex. I will look into those two books and I appreciate the recommendations. I've been able to avoid fluid dynamics since college and it is now coming to haunt me!
RE: Minimum velocity to keep particles in suspension
If you miss 10% of your biggest possible particle, it that OK because you can collect 90% of the particles?
Or do you need to suspend 99.99% of those maximum sized particles so you know you are not letting any stay out of solution?
If you only suspend 10% of your maximum sized particle, is that OK because your sampling is still sufficient to tell you are "some" of the particles are present?
RE: Minimum velocity to keep particles in suspension
RE: Minimum velocity to keep particles in suspension
RE: Minimum velocity to keep particles in suspension
(Whether or not you need to include a mixer is not the point)
RE: Minimum velocity to keep particles in suspension
"Whom the gods would destroy, they first make mad "
RE: Minimum velocity to keep particles in suspension
the fixed plate mixer stirs the liquid and solids to agitate them slightly at low flow loss, and the sampling tube extracts the mix at a known height so you don't always get junk from the bottom of the pipe.