pictures

[RCOX]

No pictures from me tonight. Your site says 1920 kb max, yet it will not take pictures even after I downsize them to 134 kb, what gives?

[phil (admin)]

Adding those sharp 90-degree elbows can really drop CFM substantially.  I'd try to figure out ways to get rid of the elbows.

[RCOX]

Phil: with the limited real estate where the separator sits I couldn't think of any other way to do this unless I use some flex and curve it up and around a little more. Suggestions?

Chuck: the outlet is about 3" down from the top, 1/2 the diameter as suggested and it is also about 3 1/2" up from the baffle. This picture doesn't show that too well. If you think it should be more, what is your suggestion? I am open to all.

I was just wondering if you thought the accumulator might also be part of the problem or not. With the lexan front I am able to see a lot of swirling around and was not sure if that indicated a problem or just natural air pattern. I still really like the design and only had to buy a couple of items, the rest I had laying around the shop.

[RCOX]

Another thought on your suggestion. Would it be better, where I have the 90 degree ells to replace them with 2-45 degree ells with maybe a short 6"straight run between each 45? I think I will have enough room to do this if you think it will help. That is what I have done on the pvc main runs in my original setup.

[phil (admin)]

Phil: with the limited real estate where the separator sits I couldn't think of any other way to do this unless I use some flex and curve it up and around a little more. Suggestions?

Many users have removed the blower from the base of their DC and turned/mounted it to the wall above the separator.  Then you have a straight shot from separator to blower inlet.  You can then mount the filter to the side of the blower and avoid another elbow.

[phil (admin)]

Another thought on your suggestion. Would it be better, where I have the 90 degree ells to replace them with 2-45 degree ells with maybe a short 6"straight run between each 45? I think I will have enough room to do this if you think it will help. That is what I have done on the pvc main runs in my original setup.

That is better than what you have now, but mounting the blower higher than the separator would be even better.

Some people don't want to start disassembling their units, which I understand.

[RCOX]

Phil: you are correct, I really don't want to tear my dc apart at this time. Raising it higher sounds like a better idea. Chuck also brought this up and I have 12 foot ceilings so have plenty of room.

Chuck: I do not take this as criticisim at all. I asked for opinions and that is how I look at this. As far as the tweeking goes, I told my wife that I probably would never be completely satisfied with my setup so would have to keep working on it. Best way I know to get new stuff. She understands that, because her sewing room is also a work in progress.

Thanks to both for your input, it has been helpful. Now back to the shop and she what I can make of this.

[retired2]

Another thought on your suggestion. Would it be better, where I have the 90 degree ells to replace them with 2-45 degree ells with maybe a short 6"straight run between each 45? I think I will have enough room to do this if you think it will help. That is what I have done on the pvc main runs in my original setup.

It appears you have four 6" short radius (1xD) ells between the accumulator and the DC inlet.  Short radius ells have considerably more friction loss than a 1.5xD ell.  A 6" 1.5xD ell has losses equivalent to12 feet of straight pipe.  For further comparison, a 2.5xD ell is the equivlent of only 6 feet of straight pipe.  No way of knowing what the friction losses are for your accumulator, but I suspect it is the equivalent of at least another 90 degree ell.

Above the accumulator you have two short radius 45 degree ells that appear to be 4" in diameter.  Two 45 degree ells produce the same friction loss as a single 90 degree ell, that is IF they have the same bend radii.  So, if these 45 degree ells are 4" in diameter and 1xD bend radius, they add the equivlent of another 6 feet of straight pipe.

If we use the losses for 1.5xD ells, your current configuration is roughly the equivalent of roughly 66 feet of straight pipe.  I can't confirm the data, but my notes show the loss for a 1xD 6" ell as the equivalent of 24 feet of straight pipe.  If that is correct, your losses from just above the accumulator to the DC are equivalent to more than 130 feet of straight pipe.   

So, one way to reduce your losses is use all long radii bends.  I have a 5" system and I use 1.75xD ells from Oneida Air. 

[RCOX]

Chuck: I had the setup you describe just before I changed to this one, with the only difference being the separator. I was using the Rockler design, entry and outlet on the outer edge of the lid and a 90 degree ell in opposing directions on the inside. Each one worked great but when I would change from 1 line to the other, the 1st can would empty into the dc. If you think using the Thien baffle design would prevent this it is worth a try. You are correct in the 1900 cfm and plastic trash cans. When I was using the other setup I could collapse the can that was shut off. I had to leave a blast gate partially open to prevent this and I think that is why the opposite can would empty, there being enough air flow to scrub the can. Do you this would happen with the Thien baffle design or would the baffle be enough to prevent the scrubbing action? I could use the original Thien design, top entry and exit, connected with a very short run of 4" flex to the entry point and a moderately longer run from the separator to the dc 3 way wye you referenced and eliminate a lot of hard 90's in the process. This would take care of the concerns expressed by yourself, Phil and Retired2. Any thoughts about the possible scrubbing vs eliminating wyes and the ensuing loss of suction will be most appreciated.

[RCOX]

Retired2: I appreciate your input. I knew there was a difference in suction loss with different ells but had never calculated it out. I used some 45 degree ells with a short section of pipe between trying to reduce loss. When you actually put numbers to it, it really changes the whole picture. I think Chuck is on to something with his idea of trying 2 separators. I already have nearly everything I need to change over, I would only need to build the baffle setup for the cans I already have. Will wait on the answer back from Chuck and give it a try. Thanks for the eye opener. 160 ft of pipe equivilent, just from above the accumulator to the dc. Never would have guessed. Thanks

[retired2]

Retired2: I appreciate your input. I knew there was a difference in suction loss with different ells but had never calculated it out. I used some 45 degree ells with a short section of pipe between trying to reduce loss. When you actually put numbers to it, it really changes the whole picture. I think Chuck is on to something with his idea of trying 2 separators. I already have nearly everything I need to change over, I would only need to build the baffle setup for the cans I already have. Will wait on the answer back from Chuck and give it a try. Thanks for the eye opener. 160 ft of pipe equivilent, just from above the accumulator to the dc. Never would have guessed. Thanks

I don't know of anyone who has done accurate measurements for the losses associated with Phil's separator, but I think Bill Pentz claims that "trash can" style separators can use 4+ inches of static pressure.  I don't know if that number is in the ball park for a Thien separator or not, but if so, for a 6" pipe at 4000fpm, that's another equivalent 100 ft of straight pipe.

[RCOX]

Chuck: you are correct about my shop being a one man show. My shop is 14 x 48, with most of the action in the front. My dc is centrally located with 1 line going to the front to a table saw, a Jet 22/44 oscillating drum sander and a piece of flex hose for whatever. The 2nd line goes to the rear to a miter saw cabinet (primary tool on that line), a 6" jointer, Rigid lunch box plane, band saw, horizontal belt sander and a router table. I also have a 2" line coming off of the 2nd main that goes to the front, to an over blade hood on my table saw. The miter saw cabinet stays connected as does the table saw and drum sander, all other tools are on mobile bases and gets moved around as needed. From what you are saying, I could build 2 separators and leave the gates open to the miter saw cabinet on 1 line and leave the gate for the table saw open on the other line until I needed another tool at which time I could close the respective gate and open 1 for the other tool. I also have 2 metal 30 gallon trash cans I can use for this in place of the rubbermaid brutes that I now have. Thank you for your help.

[RCOX]

Retired2: I hate to say it but if we keep going my dc will be blowing instead of sucking. I do know that I do not have access to the equipment needed or the knowledge required to do this type of testing. All of my assumptions have been made of the redneck type testing, putting my hand across an opening/connection and having my wife open and close blast gates until I make up my mind what I think the problem may be. I am fortunate to have a wife that will help me indulge my curiosity.

[RCOX]

Chuck, the more I think about it the more I like your idea of using 2 separators. It will be next week before I can start on this do-over but am going to give it a try. I am off work during the week and will just to see what my evenings bring before getting to this but think you may have hit on a solution. Thanks to all for your input and suggestions. Will post the results in a week or so.

[phil (admin)]

I don't know of anyone who has done accurate measurements for the losses associated with Phil's separator, but I think Bill Pentz claims that "trash can" style separators can use 4+ inches of static pressure.  I don't know if that number is in the ball park for a Thien separator or not, but if so, for a 6" pipe at 4000fpm, that's another equivalent 100 ft of straight pipe.

It is difficult to make generalizations here because the implementations vary by a wide degree.  Some use a side inlet, some use top inlet.  The diameter of the drum tends to vary from one implementation to another.  And some units are just plain better built than others.

One of my units with a side-inlet can easily best a cyclone in terms of frictional losses.  Basically, shorter path = less friction.