and the region with soap foam corresponds to the downward flow.
Then it is considered that particles moving near this apex cone surface
will be affected by the upward and downward flows.
Fig. 15 shows the results of particle trajectories obtained by use of
CFD simulation in the high inlet velocity condition. Figs. 15-a and b
correspond to the particle diameter of 1.3 and 1.0 μm, respectively.
For the 1.3 μm particles, the particles are collected on the cylindrical
wall region and are not affected by the flow difference near the apex
cone. On the other hand, for the 1.0 μmparticles, the particles move to
the lower zone of the cylindrical wall due to the high inlet flow
velocity. But all particles are moving in places away from certain
distance of the apex cone. Then, from the trajectory calculation shown
in Figs. 15-a and b, the particles are not strongly affected by the flow