J. Phil Thien's Projects

The fines will end up in the filter pretty much whether the filter is above, or below, the blower.  Adding a clean-out at the bottom would allow you to use compressed air to clean the filter, and allow the dust to settle into the cleanout.  The only problem I see, though, is that any hole you'd put in the end of the filter would likely create a ledge, where most of the debris would accumulate (instead of falling into the cleanout).

Making the filter easily removable so it can be taken outside (for cleaning) may be a better long-term solution.

Excellent work Lance, this is going to be very helpful for others than may attempt the same some day.

Super-nice work, Don, great execution all around.

Okay good luck Lance, I hope it goes easier than expected, and I can't wait to see the results.

Quote from: nucww on October 19, 2015, 10:12:48 PM
A modification that I have been considering is to use a 5" base pipe and expand to a 10" wye.  Before the transition to the 10" pipe, place a 3" pipe inside the 5" pipe after the spiral vane. The 3" pipe goes into the 10" wye. At the end of the 3" pipe is a 5" or 6" pipe  that goes out of the other end of the wye.  At the transition from the 5" to 10" pipe add an internal transition on top of the 3" pipe that maintains a 1" channel between the outer transition and the inner transition.  When it is about  8" in diameter, collapse it back down to the 3" pipe inside the 10" wye.  If the dust stays on the outside surface, the dust flows outside the 3" pipe expands to 10", hopefully stays on the outside of the pipe and falls outside the 5" or 6" pipe with very low air flow and air flow without the dust is always moving forward and goes to the outside area between the 3" and the 5" to 6" pipe and hopefully has minimal pressure drop.  Without the transitions, I do not think there will be enough airflow to get the dust to the outside of the 10" pipe.  With these clearances, my main concern is dust hangups (on the spiral vane and the 1" channel) requiring frequent internal cleaning which means more design features to take it apart easily.

We're on the same page, someone just needs to do some testing.

Quote from: DennisCA on October 05, 2015, 12:00:38 AM
Thanks, I am approaching the stage where I am not sure how I will proceed. Just how the heck am I going to get this motor lifted in position, and how will I make the frame for it, etc.

Designing while you're building goes like that.  Not many alternatives, though.

Looks fantastic, amazing work!

Don't get your hopes up, this entire idea may turn out to be one of my worst.

Quote from: sploo on September 16, 2015, 05:07:28 PM
I think the idea was that it, also with the inlet being angled down slightly, encourages the dust to spiral down (i.e. more than just gravity) and so less of it ends up getting pulled into the outlet. Easy to say, time consuming to test, and probably very hard to perfect (assuming it's actually a benefit at all).

Reading through the "Here's the plans" thread, I see that a 1.25" wide slot in the baffle was mentioned for a 20" diameter separator, as well as some thoughts that a smooth surface on the baffle helps. I was wondering if a thin sheet for the baffle would also be beneficial - i.e. perhaps a 1/4" thick sheet of smooth plastic, rather than a 3/4" sheet of MDF or ply?

If you watch and of the youtube videos of clear-sided separators, you'll see that the debris actually falls quite quickly.

I haven't tried a helical ramp, the Pentz version really seems like a complete knock-off of the Donaldson-Torit and I've studied their approach a little.

I think we like to imagine that the helical baffle "trains" the debris to the outside wall where it is forced lower until the air reverses and the debris drops.

The reality is, though, that having that helical baffle means we've now basically made a winding sort of rectangular duct.  And if you've ever watched sims of airflow through a rectangular duct, you know there is a lot of weird turbulence within them, I'm not really sure how much they force debris to the outside wall.  Maybe the much heavier stuff but the much heavier stuff isn't the problem anyway.

Don't let me dissuade you, by all means give it a shot.

Quote from: sploo on September 16, 2015, 03:14:33 AM

Quote from: phil (admin) on September 15, 2015, 06:43:46 PM
No, the cone wouldn't work, you can't really put a larger separator on top of a small drum.

The outlet tube should expend roughly 1/2 to 1D of the tube, so a 6" tube should extend 3" to 6" into the separator.  Exception is if you're doing a 2x high separator, in which case the inlet should be held to the top and outlet tube should extend past the bottom of the inlet by 1/2 to 1D of the tube.

Thanks Phil. I'll see if I can get a larger diameter can/drum then; I guess it would also make the build simpler. Whilst I'm struggling for height with a cyclone, that's obviously not an issue with your separator, so is there benefit to going for a 2x high design? I can see it might be useful in that you've got material hugging the outside wall long before it's dropped enough to get near the opening of the outlet tube, so might be beneficial to separation.

The 2x high design has increase separation a small amount and reduced pressure drop a small amount as well.

No, the cone wouldn't work, you can't really put a larger separator on top of a small drum.

The outlet tube should expend roughly 1/2 to 1D of the tube, so a 6" tube should extend 3" to 6" into the separator.  Exception is if you're doing a 2x high separator, in which case the inlet should be held to the top and outlet tube should extend past the bottom of the inlet by 1/2 to 1D of the tube.

Side inlet has the least pressure drop, so that is superior.  With side inlet, distance between bottom of lid and top of baffle only has to be large enough to accommodate the height of the inlet.

The tighter the radius, the greater the separation, but also the greater the pressure drop.  I'd go with as large a D as your drum will allow.

Quote from: alan m on September 14, 2015, 05:01:51 AM
what ideas have you got.

Bunches of them.  I've been pondering some and realize how terrible they are.  By the weekend I'll hopefully be able to try a few out.

I've started accumulating some parts for more experiments on my end.

I have a couple of ideas for maximizing fines separation but need to get my test rig built.