Baffle Diameter

[MunchyMonster]

Almost all (I only say almost because I might have forgotten one) of the baffles I've seen posted here have used the diameter of the drum or bucket as the diameter of the baffle and lid construct.  I've been looking at the "tophat" design and wondering if there is any reason to do so?

With the tophat design it would be fairly simple to create a Thien Baffle Chamber with a smaller diameter than the opening of the container being used.  This of course assumes you have room to mount your hardware (there is of course a lower limit to how small you can make the chamber, right).  But you could also go in the other direction with a little bit of planning and make a chamber bigger than the diameter of the container being used.  Given the ingenious things I've seen done, I'm sure going either way is well within the realm of feasible modifications.

So has anyone given any thought as to what works "better" from a chamber diameter point of view?  Is a small diameter chamber better at accellerating small particles against the walls thus pulling more fines out of the stream?  Does a larger chamber allow more time  bumping against the wall and a greater chance to precipitate due to a longer drop out slot?  ???

I built my first "quick and dirty" seperator and I'm very happy, but curiosity has got me thinking about this "tophat" design.

-MunchyMonster