J. Phil Thien's Projects

Well... I tried to read the paper.  Way over my head!

For those of us without engineering and/or physics degrees, what does it mean?  Will adding a deswirl device in the outlet improve performance as a dust separator?  Will the through put be increased, but also the amount of dust particles going to the filter?

Inquiring minds want to know!  :-)

You'd need more hose to do this, but I'd be inclined to spin the ring of the old DC 180 degrees and make one long sweeping turn rather than an "S" turn.  I suspect you'd have much less friction wrapping the hose half way around the the DC bag/filter assembly, than executing two sharp direction changes.

I was planning to place the separator and DC under the outfeed table behind my table saw.  It would consist of a couple of feet of duct feeding directly into the separator and another foot or so of duct to get to the collector.  If the design is successful, the dust collector will only be pulling air thru the separator and filtering fines from the output air flow.  This unit would be dedicated to capturing dust from the saw. 

I was also thinking about attaching a smaller unit (shop vacuum powered) to pull from the blade guard.  This unit would be mobile and could be attached to the miter saw, drill press, router or sander as needed.  Might not be the best solution, but given my budget and the the equipment that I already have, it seems reasonable.

Any residual fine dust escaping into the air is scrubbed by a ceiling mounted JDS 1200 cfm airfilter.

So back to the earlier questions....  Does anyone have any thoughts on the size that would be appropriate for a top hat DS in front of a 500 cfm DC?  Would anyone be willing to contribute to a "database" identifying measurements of successful separators?

Thanks,
Kevin

I had an opportunity to read that material over the holidays...  Some I understood, some I think you'd need an engineering degree to really be able to process.

So, back to the original question.  Some folks have built separators powered by low cfm shop vacs.  Some have built separators powered by high cfm, 1.5 HP (or larger) dust collectors.  Due to power and space considerations, I'd like to use my 600 cfm, wall mounted dust collector to pull through an appropriately sized top hat separator.  Is there any anecdotal knowledge in the group that could give a starting point for the construction of an "off sized" top hat separator?  For instance, given a stated cfm, could we approximate an acceptable volume inside the top hat where the air would maintain sufficient speed to throw the dust to the outside wall, but not so fast as to generate more than a minimum amount of bypass?  Could we perhaps get a guideline that identifies the optimal space (if any) below the input duct (as a percentage of input duct diameter) to allow the air/dust to pass below the duct and maintain the cyclone?

Would anyone be willing to contribute these these or any other ratios that seem meaningful along with how satisfied they are with the performance of their build?

Thanks,
Kevin

Hi all,

I've searched the forum for some advice on this subject but haven't seen much...  Maybe it's here and I simply haven't set my search criteria correctly.

Here's my question: Is there anecdotal knowledge relating diameter, height and inlet/outlet sizes of the cyclone to the CFM of the air moving through it.

I'm sure there must be differences between the requirements for a shop vac powered system, a small (500 CFM) single stage dust collector and a large (1000+ CFM) collector.  I also think that the side inlet modification must be much more efficient than the original version with two tubes entering through the top.

Any thoughts on the above would be greatly appreciated, as I'm hoping to start building my separator right after New Years.

Thanks,
Kevin