J. Phil Thien's Projects

Quote from: retired2 on November 12, 2013, 02:15:29 PM

Quote from: Jerry Thompson on November 12, 2013, 05:46:49 AM
The Harbor Freight DC has 4'' inlet/outlets.  The dust deputy has 6''.  Would using reducers effect the performance enough to make this an unwise choice?
It would be used one machine @ a time, e.g., TS, 8'' jointer, 12'' planer and a 12'' miter saw.  I think the longest pipe run would be 8 feet. I do not know exactly where I will place the set up yet.
If this is fool hardy I will try to figure out how to make a Thein separator.

The Dust Deputy and the Thien Separator are both large bulges in the conveying line, so using reducers is unlikely to adversely affect the performance of either one by very much, especially when the conveying lines are so short.  A far better question might be how do the line losses of a Dust Deputy compare to that of a Thien Separator in a system where all else is equal.  I have yet to see any test measurements for such a comparison.

Yes, but your effective SP will be determined by your smallest diameter restriction(s).  If the adapters/connectors decrease the size of your pipe, then it is the connector or other restriction that drives the result, not the pipe diameter.  Right?

-- Bradley

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

Okay, and the commentary on the use of turning vanes at the entry to the Thien chamber, especially w/ regard to the top-entry situations?  These are worth a 50% reduction in SP drop at elbows.

Likewise, what about the use of stream vortex inducers just inside the feed duct where it dumps into the Thien chamber?  Tuning of this twisted jet of air would help compress it and thereby accelerate it; and it's rotation could be oriented to get it to hug the wall of the chamber at the bottom where the dust needs to be deposited?

--Cheers, Bradley