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redo complete

Started by RCOX, November 29, 2011, 11:52:01 PM

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RCOX

OK. My redo is complete. All new 6", 24 gauge stove pipe. All but 1 sharp 90 replaced with 30 and 60 degree ells. Ductwork runs down to 6" wyes and blast gates then to 4" flex to the tool ports. I am thinking of changing some of those to 6" also, where possible.

Now for my delimma. I thought I lost a lot of suction with the separator so I built a simple manometer from instructions found on the internet. Without the separator I was pulling 10" of suction. With the separator suction fell to 6". I also noticed that when I was using only 1 - 4" gate that I was pulling dust up out of the collection can. I could partially open the adjacent gate and would stop pulling dust out of the can but the "working gate" lost a lot of suction. I don't know if it was actually bypassing or just pulling the dust into the tophat and just swirling around. Ran out of time. Hopefully tomorrow I can determine if it was bypassing or not.

Before I found the plans for the Thien Baffle, I had been looking at the super dust deputy from Onieda. I also saw a cyclone modification on ebay from a guy in New York. My question is this, is this type of suction loss normal for any type of separator or have I done something wrong in the way I built my separator?

I do a lot of planing and sanding rough lumber and am getting tired of constantly clogging the filters on my dc so would like to have a separator to cut down on this problem. I just don't know if I have made a boo-boo or if any type of separator will give comparable suction loss.

Any thoughts or suggestions from the readers and/or Phil will be greatly appreciated.

Thank you,

Raymond

galerdude

Do you have pictures of your separator construction? Or possibly a link to that info?
I, personally, am clueless about any possible suction loss. In my scenario I had used a plastic trash can topper separator (?) for 3 to 4 years with a wynn filter and had totally, well almost totally, plugged my filter. So right after building the Thein TopHat, I thoroughly cleaned the filter and wound up with more suction than I had been used to for quite some time. I was, and have been, ecstatic since then about the performance. Not a very good comparison, I know, but that is my limited experience with the suction scenario.
   With yours, that does seem to be a lot of suction loss, so I do hope that it's something that can be remedied. Hopefully, others more experienced will post their clues and suggestions on this matter. Do post some pictures or links to your construction, though. I think that would be beneficial.

Thanks,
Gale

phil (admin)

Here is a link to a previous thread w/ pics:

http://www.jpthien.com/smf/index.php?topic=533.msg2770#msg2770

A 4" drop seems high, but not surprisingly high given what is going on.  I do know that conventional cyclones use large impellers and the manufacturers stress proper ducting because there is a substantial drop through the cyclone.

I'm perplexed by the problem w/ the possible bypass w/ a single 4" port open.  I can only imagine there are leaks in the separator somewhere (which could also explain some of the drop you're seeing).  So maybe with only a single 4" port open, the blower is finding a leak in the separator somewhere and that is bringing some dust with it.  When you open another port, the blower "finds it easier" to bring the air in through that open port instead of the leak.  But I'm just guessing at this point.

Perhaps when you have more time you can try wrapping all your seams with some blue painter's tape (clean the dust off first) from the outside, and see if you still have a bypass issue?

Let us know!

galerdude

Okay, thanks Phil for posting that link; read thru your build.... ::)....you've got determination mister, wow ;). Two quick questions;

  • Where are you, in the system, performing the test with the separator hooked up?
  • And where in the system are you performing the test with the separator disconnected?
Also, could you post that link for the DIY manometer? That sounds like a fun little thing to do 8).

Thanks,
Gale

RCOX

Phil: thanks for your response. The cyclone I mentioned is just the body. You can either put a blower on top or connect a single stage dc to it like some of us are doing with your separator design. I will try your suggestion on taping all seams and trying again. (after I complete this project I am doing for the wifes sewing room.) First things first. I will say the separator has cut down on the filter clogging, even with the suction loss I am experiencing. The super dust deputy, you are probably familiar with.

Galerdude: I am doing the test at the same place, trying to keep the test apples for apples. That said, my tests are done at the longest distance from my dc. That is through about 32' of 6" pipe, a 4" blast gate and 15' of 4" flex. This is where I put a portable Delta downdraft table to do hand sanding with a random orbital sander. At the end of the same hard pipe but only 2' of 4" flex I have a Jet 22/44 drum sander. These are my major fines generators.

As far as the manometer, I just typed manometer in my bing search engine and started looking. When I came to this project I decided to give it a try. Not sure as to the accuracy but it is a simple apples for apples test . The easy instructions are: place a scrap of wood vertical ( I used a piece of 1/4" plywood about 15" wide by 24" tall) place a clear tube in a u-shaped loop on this board, add some food coloring to water and pour into the tube until the loop is about 1/2 full. Place a mark ( 0 ) even with the levels of water. Then I measured/marked inch marks up and down from that point. 7 or 8 inches each way is more than enough. I plugged one end of the tube, drilled a hole through a piece of 3/4" plywood and forced the other end of the tube into that. That piece of plywood then is placed over the end of your suction test hose. When it pulls the water up you read both measurements. 1 side goes up 5" the other side goes down 5", this equals 10" suction. At least that is the way I understand it to work. That is how I arrived at my numbers.

Thanks for the input/suggestions. I will try to post some pictures in the next few days, of the redo and the manometer. Maybe someone else will get a kick out of it also.

Tried to add manometer pictures now, hope they come through.

Raymond


RCOX

Resized these pictures and trying again.

Raymond

galerdude

Thanks for the pictures and info on the manometer! I gotta try that one.
Just trying to eliminate the obvious so please bear with me......got more questions;

  • Did you switch to the metal can and if so, did you put a clear monitoring window in it, also?
  • If using a collection can with the window, is the window sealed up tight?
  • Concerning the seal of the Thien TopHat to the can; is that a constantly good seal? The reason I ask that is, once after emptying mine, I put it back on cockeyed ....lets just say... we hope that doesn't happen again :-[.

Thanks,
Gale

RCOX

Galerdude: Yes, I am using a metal collection can. Yes, I put a window in it. When I built it I cut the hole in the can, cut the window 1" larger on all sides, drilled the holes through the window and can, placed a bead of silicone around the hole in the can, bolted on the window squishing out the silicone and then wiped around the inside and outside to complete the seal. I have been un-able to detect any leaks here. The under side of my tophat is made of 3/8" mdf with the hole cut to be a press fit around the top of the can, it rests on the 1/4" mdf that I made the baffle from. I have not noticed a leak in this area but will check again to be sure.

I have read on different posts about the shape of the collection can not being of importance. I have thought of raising the tophat and mounting it on the wall, adding a 4 sided funnel tapering fron 21" down to a 6" connection to the can. Any thoughts on this vs trying to build a round funnel. The 4 sided method will be a lot easier to build but will it be detrimental or no difference. Just curious. Doing this either way will make it easier to empty the can.

Thanks for the questions. The more things to check the better. I know the answer is out there.

Raymond

galerdude

Raymond, thanks for the info. What a mystery ???  I'm gonna have to put together one of those manometers and test mine now. Could be a few days but I'll post when I know sumpthin'.

Don't know for sure on the shape of the collection can but I've read where it's not supposed to make a difference. Maybe you could make it a 6 sided cone. A little easier than round. Anything you do to make it easier to empty and not sacrifice the separation/suction, would be a huge plus, I'm thinkin' ;)

Thanks,
Gale

RCOX

Phil: I found some leaks around the edge of the Lexan. Not sure if it is enough to create the problem I am having or not.  I will seal it with silicone instead of tape. Easier and should seal it better. Thanks.

Galerdude: The manometer is easy to make and it gave me a more realistic test than just sticking my hand over the flex hose like I was doing. Have fun with it.

I have some pictures of the redo, hope they come through.

I will be having trigger finger surgery on my thumb and three fingers of my rt hand next week so have to try and finish this project for the wife. My separator will be on hold for a few weeks during recovery.

Raymond

retired2

Raymond,

Sorry, I don't have time right now to read this thread thoroughly.  However, there is a very good thread written about SP loses that I wanted to point you to.   You may find that your 4" of sp loss is not out of line depending on how it was measured.  Here is the link, read it thoroughly to see if it relates to your situation.

http://www.jpthien.com/smf/index.php?topic=466.0

Also, one other comment.  With the power of your system, I would bet a dozen donuts you are getting leaks around the collection can seal.  You have two hard surfaces forming that seal, and if your can is like most it has at least one rolled seam that creates a bump on the rim.  Do a smoke test.  I finally put a rubber gasked in my top hat to make sure it wasn't leaking. 

phil (admin)

You might also want to caulk the seams of your can.  I thought you were still using the plastic one.  I've had a couple of metal ones now that leaked quite a bit around the bottom and the side seam.  I wouldn't have thought it but in going over them with an incense thingy the smoke got sucked right under and into the can when I was checking the side seam on one of them.

galerdude

Wow! Nice Shop.
Wish you the speediest recovery possible with your surgery!
Hoping to hook up the manometer permanently in the system. Mine is outside in an attached room so am thinking this would make a nice accessory in case something is amiss. Should have some comparison data for you to ponder over by the time you get back to this.

Thanks,
Gale

RCOX

Galerdude: Thanks. When I had my left hand done, it was no big deal. Just had to let the incision heal and not break apart. Out of the shop for 2-3 weeks. It will improve my grip though. Can't grip anything with it as it is. Thumb and fingers lock up in the joint and don't want to flex.

Will keep checking back to follow your progress with the manometer..

Raymond

phil (admin)

I, too, would like to wish you a speedy recovery!  Hope this one goes even better than the last!