Cyclone Duct - Ceiling or Floor?

glenn bradley

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The great thing about DC threads is that there are plenty of them. After diligent searching and getting a wealth of results, hitting Bill's page and all that, I still would like to present a question to the forum.

I have read thoughts/opinions that a duct's riser should occur near the tool, not at a gathering point near the DC. This "gathering before the riser" design happens with most under-floor installs I have seen but most ceiling installs use vertical drops.

Baseline: A 2HP cyclone with the inlet about 5' 8" above the floor.

Question/Comments:

What are your feelings about exiting the cyclone, angling down to the floor and then fanning out to three near-floor level machine ports with blast gates?

What are your feelings about exiting the cyclone, angling up to the ceiling and then fanning out to points where you would drop down to the three near-floor level machine ports with blast gates?

More Info:

The runs will be much shorter angling down to the floor. The runs will go along a floor/wall joint (no foot traffic area). There will be only multiple 45* bends, no 90's. Only one tool will be used at a time.

The runs will be much longer if I go to the ceiling but we are still talking about a max of 35'. The drops would have to be 90* with a 7' vertical to each machine.

I'm leaning towards the floor path. Your thoughts?
 
glenn,
what`s your desired result? are you more concerned about actual dust collection or about workability in your shop? anything on the floor gathers "stuff".....any trunk in a duct system needs to allow for cleanout due to the nature of airborne chips, they do fall out and build up in the runs over time. having the duct go up from the machine will cause some of the heavier chips to fall out of the airstream before they reach the trunk causing you to have to clean at the machine more.
there ain`t no perfect dust collector/ chip extractor.....i`ve seen 150hp fans with 20" trunks restricted to about half diameter from the chips building up.
bottom line plumb for workability and allow for cleaning the runs.
 
Hi Glenn, wanting to build an install a cyclone myself the only thing I can tell you ( and that you problably have done already) is that you should look and read very thoroughly Bill Pentz's web page. There is plenty of information about cyclone ducts, diameters, loss of suction due to bends an minimun HP needed.

I have almost everything figured out, the only thing I need is getting three phase current so that I can start building it.

If I remember well he recomends 3HP motor at least, and a blower that moves 800cfm of air but I'm not sure I should look for it again.:dunno:

Looking forward to see it finished:thumb:
 
I don't think it really matters where your vertical drop is. If you do it closer to the cyclone, then you obviously only have one vertical instead of one for each tool, and that would save some pipe. As far as how the system would work, each tool would still only have one vertical to negotiate, so I think there would be no difference. But if at all possible, have at least 5 feet of straight run to the cyclone inlet. Something about getting rid of the turbulance from an angle in the pipe helps separation in the cyclone. That is also why I believe Bill Pentz recommends angling the inlet going into cyclone body, so there is no turbulence getting the air flow to head down the cyclone chamber.
If I had my dream shop where I had a walk out section under the shop for lawn tools, etc, I'd have the cyclone underneath and make my runs under a wooden floor. Everything would be down hill as far as the chips and dust goes. Jim.
 
Glenn, when the "Install" finally gets to the top of my "to do" list, I'm set up for under floor installation. I think that either way one goes, ie; ceiling mount or floor, the most important thing is that you need the LAST 4' to 5' going into the cyclone to be a straight pipe that is aligned with the inlet to the cyclone so there is NO air turbulence to deteriorate the flow rate. It seems that this 4' to 5' should be at a slight angle downward, because some, if not all, cyclones are now built with the inlet sloped downward 10 to 15 degrees). My riser from the in-floor channel will be just prior to the last 5' straight pipe into the cyclone using two 45*'s and one "modified" 22 1/2* to match up with the cyclones inlet angle.

I believe that by following the principles above and making a system that uses the Shortest duct runs with the Least number of bends, will be the most efficient system, whether it is a ceiling mount OR floor mount system.

Note: 1. The above, AND below are just "MY thoughts", from all my
research.

2. The system should always be run long enough AFTER any
machine cutting to clear the ducts, and I personally feel that
machines that process "Green, (damp wood)" should probably
closest to the DC.:dunno:

3. Clean out, (should a blockage occur), in either system can be
easily accomplished using a Plumber's snake inserted at ANY tool
connection with the DC turned on, OR, you can install a
removable plug at the end of any main trunk duct to enable the
snake's insertion.

It will be interesting to see what everyone else's ideas are from THEIR Research. and/or actual use.:D
 
Another great thing about the forum is that many member's responses jog our brains. I should fill in some gaps now that I am pretty dedicated to making floor runs. In my case both floor runs will actually be a few inches off the floor. One run will be between the table saw and the outfeed table. The other will be along the base of my primary storage wall. Neither of these locations serves foot traffic and each gets "cleaned" by occasional blasts of air as no broom can really reach these areas anyway.

My thanks to all respondents and I will continue to add pics to the 'G0440 Arrives' thread as I go along. The blast gate positions should be an interesting challenge. I know one guy who used choke cables (like for your old lawn mower accelerator cable, kinda). This may work out for the TS and the RT lower port. I have also seen the gates mid-duct and this is possible as well.

Fun, fun, fun.
 
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