Top Hat Separator Challenge

[retired2]

For all of you folks trying to find that next performance enhancement for your top hat separator, here is something to ponder, and possibly try.

Have you ever noticed that a top hat separator with a tangential side inlet looks very much like a centrifugal fan without an impeller, the major difference is the air flow is reversed, i.e. the outlet is the inlet, and the inlet is the outlet.  The other far more subtle difference is that top hat builds always have the outlet port centered, while that same port on a fan is always off-center.

So, the question becomes, is the outlet port in top hat builds in the optimum location, or sweet spot?  Is there a slightly off-center location that improves flow rates?  :D

[bpotts]

Interesting question.  I must say, yes, the port is in the only position that this Thien chamber can functionally support.  I'm no scientist or engineer, but I believe that what is good for the fan chamber ain't good for the Thien chamber.

The idea you bring up attempts to apply one design detail to 2 functionally distinct and separate locations, that have divergent needs and forces at work.  Functionally, the location you describe pertains to the fan box, where the impeller imparts energy to the air/fluid in order to accelerate it via compression against the impeller blades.  The ancillary dust separation chamber, on the other hand, endeavors to decelerate the waste stream so the dust falls out, but the deceleration can't restrict the volume of air flow through the chamber, and this deceleration is induced by a centrifugal path.  We already know that any eccentricity in the resulting vortex induces turbulence and any exit eccentricity will increasingly intercept the waste stream and siphon off dust, both of these results would be bad for the process.  Even though we have mounted the blower boxes directly to the top of the separation chambers, it is more appropriate for us to think of them as 2 modules/devices connected by a short length of pipe; physically doing so would allow the both alignments to successfully work within this assembled machine.

Conclusion:  Trick question.


Cheers, Bradley

[retired2]

Nope, not a trick question at all, at least not intentionally so.  My question was simply borne out of the thought that the pressure inside the Thien separator may not have a concentric profile.

Also for consideration is the fact that some cyclones are built with an inlet scroll which creates an eccentric lobe much like that of a fan housing.