Flat Baffle vs. Conical?

[WayTooLate]

Phil (or others) -
Have you experimented or tested a conical baffle?
(Where the center 'point' is higher and slopes down towards the cutout area) 

I was wondering if this would improve separation by working like an inverse-cyclone... 

Just wondering! 

[phil (admin)]

Yep, I've done it.

Many different shapes, in many different orientations, have been tried.

Don't ask my kids where their Frisbees are.  It is a sore subject around the house (they all have extra holes in them).

The cone, BTW, doesn't help separation until it starts to hurt CFM.

[WayTooLate]

Phil -
I understand what you are saying...  My kids have 'lost' a few toys because I thought I would have more 'fun' with them... 

In trying to understand what you are saying about the cones and CFM, I think your comments mean that if you have sufficient static pressure, the separator is more than efficient enough to push so much debris to the outside that it doesn't need the help from the cone.  However, once you filter starts getting clogged, the air stream slows down enough that the center duct could pull debris into it rather than circulating to the outside to drop below the baffle. 

In a real-world situation, I assume that when the airflow slows enough for the cone to help, you probably aren't pulling enough air into your tool ports.  Before your baffle needs help, you probably have too much dust on your machines and workpieces.  Since we rarely over-design our intake and dust ports, they end up being our indicator of overall system performance. 

I am needing to improve my DC system - the shop is 'clean', there is rarely anything on the floor.  However, my air is 'dirty' - the amount of airborne fines needs to be reduced.  I cannot afford a new cartridge system, I am hoping to improve separation enough that I can use better bags on my existing equipment.  Unfortunately, the better bags won't handle ALL the debris that is generated - so we need to separate it better. 

Your separator design works very well as a 'pre-separator' attached to each machine. I have 5 gal to 30gallon separators on various machines.  Now, I am looking to add another stage to pull out even more 'fines' to leave only 'super-fines'.  Any help with creating a super-separator will be greatly appreciated! 

My assumptions are:  Larger diameter separators work well to drop large volumes of heavier chips.  Smaller diameter separators are needed to generate higher rotational speeds to force fines to the outside.  Am I going in the right direction? 

If so, then placing a 55 gallon drum next to my jointer or table saw will easily catch the large chips they make.  However, am I better off with a 5 gallon bucket attached to my drum sander to entrap its finer dust?  In other words, is the diamter of the separator more important than just the amount of debris it will hold?

Looking forward to your reply (and others)!

[phil (admin)]

Most (all?) of your assumptions (diameter of separator vs. efficiency of separation) are spot on.

I don't know if it will ever be possible to catch the super-fines using my standard baffle-based separator.  Nor would it be possible with a big cyclone.  I know some say they have a cyclone championed by some to be the best at separating the fines and that they clean the filter once a year and there are no fines in it.  I can't imagine they're doing much woodworking, though, as I know people that use the same cyclone and they DO get plenty of fines that have to be cleaned from the filters.

If you can get to the point where you're moving as much air at the tool as physically possible, and your filters aren't clogging, the next logical step (IMHO) is an air cleaner.  If you're working with toxic woods or have a tendency towards sensitivity, then use a mask, too.

[WayTooLate]

Phil -
Thanks for the confirmation. 
An additional assumption that I have has been mentioned in other posts: The height of the container is irrelevant to the separators performance - everything above the baffle is critical; below the baffle doesn't matter.  The 'taller' the can, the longer you can wait to dump it, it just gets heavier... 

Thanks again for the reply!
- Jim