J. Phil Thien's Projects

I need to clean up my garage so I can make some proper sawdust, all I have right now is an enormous pile of hardboard sawdust made with a 120 tooth melamine blade. It's all I have right now and I hardly think it's a fair test to put a pile of super fines in front of it, but the result was quite a big puff of dust out the blower, no idea how much got separated but most of it, certainly.   I also don't have a hose for the thing either.

I'd say that if you have room for a cyclone, just do that, the pressure loss is much lower. Have you seen the newer oneida cyclones? they look like great value to me.

In other news, my separator is done enough for some testing.. I made the fiberglass inlet and the spray foam attachment is drying now. I'm hoping to get a felt bag for the outlet from kijiji tomorrow.

Well, it's been a while with no replies but I'll give it a go.. I think 16" is too small for that much flow - if you run the math, with 16" OAD, that's 15.5" with a 1/4" wall, minus 6" for the outlet, probably more like 6.5" to account for whatever it's made of, and you only have about 9" left, so that's 4.5"of width for the incoming air. I'd bet the pressure loss will be huge, but with 3HP behind it, you may do all right.

Back from the dead again! Progress! I have built a stand out of angle iron - it's built over tall on purpose as I will get another barrel to make a full sized waste barrel later on.

I am working on the molded inlet, here are a couple of pics of the early shape. I am waiting on my local plumbing store to come up with a 6" PVC ("weeping tile") coupler to mold in at the business end. Overall outlet will be about 7.5x4". I'm using the 'lost foam' method described by another forum member. The outlet size is more or less tuned to be the same as the area provided by 6" DWV PVC.

The foam is some super ugly used 6" roofing insulation, polystyrene foam. It's got tar and crap all over it but mostly that cut away. I'll be coating the outside of the mold with something to smooth it down before fiberglassing as well as some plastic wrap or similar over the top to keep the polyester from melting the foam. Probably some drywall comp as I have a box of some old and it's easy enough to work with and inexpensive.

You can see the hoses I have been using for testing the static pressures.

I bet you thought it'd be another 6 months before the next update, but I am here to report:

Progress!

I made the vortex manipulator today, tack welded the center pieces together and it is installed. I put it about 1 1/2" from the inlet of the blower intake. It's an "X" shape but that was just the easy way out so I took it. It's already an 8" pipe.

The spiral is installed, and I did the fitting of the center to fit the pipe. I just stood above it and cut away until I could just sight down the outside of the pipe, all around. I have pictures of how I set it up, I put the blower upside down on top of the bottom barrel piece (to accomodate the motor) and then put the top barrel piece right side up on top of the intake pipe. I used 4 bottles of oil as stands to get the right height. The fitting took maybe 20 minutes with a die grinder.

All that's left is to align/fasten the barrel halves, cut the inlet hole and make a square to round adapter.

The blower is attached to the inlet tube with 4 1/4" bolts and t-nuts.

Heh, so obviously I got right on this, but anyways, I spent some time today and made some progress.. I think all the parts are done except the barrel inlet, and I want to do that last, maybe out of sheet metal at work where we have a little brake. I cut the barrel in half, made plywood "rings" I put around the cut edges, so I can put it back together for now. I plan on putting either a bigger barrel or a brute or something under some day.

I found a piece of 8" PVC a few weeks ago, so I also made the collector - > blower pipe. I used my router to round the ends on the inside, as I don't have a bellmouth. At the blower end the rounded edges will meet up nicely with the inside of the impeller. There's a round lip on my impeller that will fit in the recess formed by the plywood rings.

I made a preliminary baffle with more 18mm birch ply. Haven't decided whether to mount it in the top half or bottom half of the barrel.

I also constructed a spiral ring out of some 1/8" hardboard, two pieces which will be glued in place (and together). It's made to have a tight fit on the PVC pipe and a reasonable fit on the barrel. It will be glued into the barrel with hot glue (and a heat gun to preheat the barrel).

The barrel top plywood piece is actually the circle I cut out from one of the barrel flanges, and the baffle is the other.

Specs of blower: 8" inlet, TEK355 BC airfoil impeller, 4.5HP motor. The unit draws 3HP worth of power once it's running. The impeller is supposed to flow ~1600CFM @ 9" so I think I'll have enough flow no matter what.  The separator will have a 6" inlet with an 8" outlet to the blower. I will be making an air straightener.

It looks to me more like a comparison between various exaggerated possible thien baffle setups. I expect the excessively tall shapes are due to materials on hand based on what it says. Looks like putting a helix at the top to guide the flow, with the blower inlet in the middle and an effective height of about 3x input diameter showed both high efficiency and low pressure drop. It doesn't show a bellmouth. If you look at the page titled "Final Design" you can come up with some ideas. I've finally got my hands on a barrel so this is timely indeed.

If I scale up the approximate ratios I see on the rendering, I come up with an 8" blower inlet, 21" separator diameter and 6" inlet with maybe 20" from the top of the inlet to the bottom of the separator. I'll try it. The helix will be a pain but I have some ideas.

I have no idea if it will work, though, he is clearly dealing with much higher velocities than we are: the lowest pressure drop was 2124 pascals = 8.5" water.

flexpvc sells 5" pvc pipe

Is it somehow worse than my current situation with no collection and big fans blowing it all out my garage door? I'm not rich but I am doing what I can.

It is my plan to vent outside so will be watching closely...

The short version is: it doesn't matter because you should be putting a deswirl device on the blower intake.

I built the scroll for the blower yesterday, took longer than I thought it would but the fit is pretty good. I put BLO on it to finish it, which is part of why it took so long. It takes forever but I really like the way BLO (properly applied) holds up to weather, and this thing is going to live in a sort of lean-to shed next to my garage. In other words I want it to survive the potential occasional wetting.

I will put up some pictures later but with an unrestricted inlet (but with no bell mouth) and outlet (which is 5 1/2" x 8") the motor draws ~36A at startup and once run up it settles to 10.9A, which is under the 11.7A rating. On low speed (1725) it draws 3.7A which is more than the rated 3.4A (1/2HP at that speed) but I expect it will be fine as low speed is really just for startup. On low speed startup it only draws ~16A, so you spin it up to low then flip it to high for less stress on the motor.

When the system is more complete I plan on characterizing the blower, measuring SP levels and determining flow.

I'm building my DC system from scratch, and I want to implement a Thien separator in my system. For the blower I will be building a housing around a 14" TEK355 DC airfoil powered by a 4.5HP motor. The intake on the airfoil is 9", so I am guessing that I will need a larger than usual separator.

Are there any sizing guidelines or rules for building an effective unit?

Here's what I am thinking so far:

Blower sits right on top of a 16-17" tall separator with a 9" bell mouth sticking in 4.5".

8" ducting, material enters the cyclone with a rectangular injector at the top of the chamber.

Baffle with a 1 1/4" slot, made of thin material and tapered around the slot area.

....

Would I be better off going with like 7" ports? I'm wondering if I build it too big, I'll probably need more flow for the separation than I will have running one tool at a time. I suppose I could just always leave a floor sweep open or something for the CFM.

Should the cyclone spin the same direction as the impeller?

I'm new here, but I just got one of those 14" TEK355 impellers from oneida. I'm pairing it with a 4.5HP two speed pool pump motor I got cheap. I haven't built a housing, but I have tried it and on high speed it moves an absurd amount of air, and it's quiet and balanced.

My original plan had been to put it with a 2-3HP motor and restrict the intake to prevent overloading, but I got a big motor for a better price so I will build my DC full size.