Interaction between two different species of particle(s) in a fluid stream
is promoted by generating turbulent eddies in a fluid stream. The
turbulent eddies are designed to be of such size and/or intensity that
the different sized particle(s) are entrained into the eddies to
significantly different extents and forced to follow different
trajectories, increasing the likelihood of collisions and interactions.
Optimum collision rates will occur for a system which maintains a Stokes
Number much less than 1 for one sized particle, and or order 1 or greater
for the other sized particle. The invention has particular application in
air pollution control, whereby agglomeration of fine particles into
larger particles is promoted, subsequent to their removal.