Granular Flow - Application
Mass flow in slot hoppers
Hoppers are common storage devices for granular materials. The dynamics
of the filling and emptying are very important. Problems range from
unwanted separation of components and flow blockage to structural failure.
The mass flow from a slot hopper is shown in the figures below. A rapidly
moving central funnel dominates. This is surrounded by more slowly moving
wedges to either side. Most of the material at the top flows out before
the material on the sides. This occurs because the upper material is free
to flow along the surface into the middle of the active funnel region,
where it is travels down and out of the hopper. A range of useful
predictions can be made for such flows. These include estimation of
dynamic loads on the walls of hoppers. Slip-stick, cyclic stress
variations and other problems can be identified.
Hopper loads at selected times
during emptying
|
 |
 |
 |
0.0 s |
1.6 s |
3.2 s |
| Download animation: |
AVI (320x240 pixels; 8.7 MB) |
|
QuickTime (320x240 pixels;
8.0MB) |
|
To
top