Airfoil Cyclone builders - some questions

[Tim in Peace River]

Hi,

It has been far too long without a cyclone question.

I bought the motor and metal 6 months ago. Until a week ago, I was leaning towards just buying a Belfab but now have decided that I must build this airfoil cyclone. I have reviewed the archives, reread the website, poured over all my notes but will have to ask.
The only question regards the cyclone outlet - What size do I make it? It appears that size matters with material fans but the airfoil section says it doesn't? Bill used 6" to test his first blower - should I use 6"? If I go bigger, do I have to taper and roll the top edge over? Is this a significant factor or a micro tweak on performance?

Would love to discuss with someone who has actually built one.

Tim

[Bob, in Lachute, Qc.]

Hi Tim,

I havn't built one (yet), but Torit- Donaldson's built more than a few. Mind you, with BI fans, so similar characteristics. Heres' a chart, on how they "proportion" their inlets/outlets.

Good luck, Bob

http://www.donaldson.com/en/industrialair/support/datalibrary/000984.pdf

[Ed/Leaside]

It is a significant factor. The cyclone outlet and the blower inlet are the same item. On the cyclones using the material handling fans, it is sized at 9". As I understand it, Bill's "test" airfoil unit used a 6" inlet as that was what was required for testing purposes. For a functioning unit, the outlet has to be 9/10" so as not to suck fines up the tube (slower air movement). But ... the airfoil opening itself is only 8 3/4 so you need a special inlet to place the air into the airfoil. There is a drawing of the required "inlet design", about 1/3 down the airfoil page.

I've had my airfoil in hand since late Sept and have almost completed drawing the housing. This is for Sheldons full height airfoil with blower outlet to 8" diameter equivalent cross section.



http://www.canadianwoodworking.com/chat/pics/pic139018.gif

[tim in peace river]

Thanks Ed,

I will re-check Bill's site - I must have missed it or maybe I was looking at an outdated version.

How are you doing yours? Having researched extensively epoxy core boat building, I am thinking of making that 10" to 8.75" tapered pipe with smooth flare at top out of fibreglass / epoxy. I could make a cardboard tapered tube and glass it both sides to make the composite. I could then make a mold for the smooth flare and glass that.

I don't know how I would make one out of PVC.

I have toyed with the idea of making the whole cyclone out of fibreglass or epoxy. Recently I noticed the plastic one on Bill's site and thought why not? I think it would be far easier than tin bashing and welding.

Folks, if there are any negative opinions - let me hear them.

Tim

[Bob, in Lachute, Qc.]

Hi Tim,

The only possible down-side to the plastic or fibre-glass, might be the lack of abrasion resistance. Not sure that would be important in a home work-shop. It would depend on your individual useage.

Oneida, uses 14, and 16 ga metal, on their 2 hp cyclones. Cyclones like the Torits, are much heavier. When you knock on those, it's like a piece of large cast-iron pipe. In fact, when I get around to building a cyclone, I'll be using a short length of heavy pipe, for the body. I can buy any diameter I want, by the foot. My intention, would be to clone the model 16 Torit-Donaldson. 2 hp, approx 1200 cfm@ 4.6" external SP. I'd probably need about a foot and a half, of 16" pipe.

http://www.donaldson.com/en/industrialair/support/datalibrary/000984.pdf

Good luck, Bob

[Ed/Leaside]

I'm thinking of chucking a 10>8" reducer in the lathe and "adjusting" it with a heatgun & forming tool, ala metal spinning method. If that doesn't work, shopmate's wife is a potter and she said she could make a ceramic inlet.

Making a tapered outlet may give you some minor problems with fit to the inlet. Rolling and soldering the thing isn't that difficult. If you go to fiberglass you'll need to make a form anyways, and you already have the metal. http://www.canadianwoodworking.com/forum/images/smilies/wink.gif

[tim in peace river]

Ed,

I am assuming you are talking about a pvc 10>8"? Can you readily buy 10" pvc pipe and reducers?

I agree that making a 10 > 8" tube from metal wouldn't be that tough and there would be a minor problem of mating that to the bottom of the blower but how would I make the smooth roll at the top?

Also, on your drawing, why does the green line (I am assuming this is the outside edge of the cage) fall outside of the blue line (vertical metal sides of blower housing)? Perhaps I am not interpreting this right?

Tim

[tim in peace river]

Hi Bob,

Thanks for your comments. I have scrounged pipe from scrap bin at work (23" X 1/4" stainless) but it is a tad heavy and a little larger than I wanted and I had trouble welding it. If I could find 18" spiral pipe such as the 6" we want for ducting, I think that would make a great body.

There is a Torit cyclone for sale on ebay - looks big and heavy!

Tim

[tim in peace river]

Ed,

Forgot to ask: have you layed out and built the blower or are these drawings a work in progress that you will use to mark and layout?

I would like to be able to layout with a paper template better than my attempt at Bill's method with the string.

Tim

[Bob, in Lachute, Qc.]

Hi Tim,

I called a Torit distributor in Montreal last spring. Have you any idea how much those cost????, lol. The lil' 16" 2 hp cyclone, was $4,600, PLUS shipping. They're sometimes available as "refurbished", for roughly 33% off.

Those things are built like tanks, because they are designed to handle a variety of very abrasive dust-loads, such as mining, or metal working waste. The two worst wear areas apparently, are at the "turn", inside the cyclone, where the inlet meets the body, and, at the bottom of the cone. Some of those cyclones can he had with ceramic wear-plates.

The blowers, are absolutely superb. Incredible static, as well as mechanical efficiency. That lil' model #16, is 2hp, yet pulls 1200cfm, through 6" pipe, at 4.6" EXTERNAL SP. That's really amazing.

If I build one, I'll probably use their blower, since I'd have to buy a fan-wheel and motor, anyway. Wouldn't be worth it, to try to replicate the blower housing, just to try to save a few bucks. The blowers, are well over a thousand bucks.

I'm in no hurry to build one, since I get almost the same draw, with my Belfab, 1,100cfm@ 4.5"SP. I just think it would be fun to build one. For now, I prefer to spend my bucks, on hand-planes.

Have a great weekend. Bob

[Ed/Leaside]

My neighbour says they are readily available, but there isn't a 9>8" reducer. Lots of neat "stuff" in the back of his shop. Hmm ... leftover piece of 8" spiral.

I think you could roll it over with a burnishing rod. The curve wouldn't have to be very large.

On the drawing: the green line denotes the inside of the outer circumference of the 18" cyclone (it's also the hub). The innermost black line is for the c-face, the circle marked 9" is the outlet/inlet, the next two at 13" & 13.75" create the lip for the motor plate. All of these circles are on the same centerpoint and the spiral has to start at 6.5" from center (clears the 12.75 wheel by 1/8"). The wheel is not on the drawing. http://www.canadianwoodworking.com/forum/images/smilies/wink.gif

As to your follow-up question: I've laid out four variations of material handling housings for the last "group", assembled three with Jim & Jean, and have, I think, sent 18 out for CNC machining so far. This one is still in process and will also be sent out for CNC ($120 including materials). If you want to try a paper template, there is a tiled version of a housing for material handling wheels on Bill's site (on the budget blower page). Download it and if you think you can work with that format, I can generate a tiled PDF of this housing for you. Agreed, anything but the "bit-o'-string" method. http://www.canadianwoodworking.com/forum/images/smilies/smile.gif



The Neighbour (http://www.belyeabrothers.com)

[Tim in Peace River]

Thanks Ed,

I see it clearly now - makes perfect sense. I do not need a tiled version of the drawing - I have access to a plotter and I can scale a pdf to print 1:1 on the plotter.

If you are willing to share it, I would appreciate that - maybe I could reciprocate the favour some day some way.

Thanks for the help,

Tim

[Ed/Leaside]

Not a problem. Send me your e-mail off-line and I'll send it along. Would you like it in a format other than PDF? It's an Illustrator file at the moment and I can export/convert it to ...

Is your wheel for 2 or 3 HP (4.5 or 5" width)? If it's the smaller one, with a 5.625" blower sidewall, this layout will have an outlet equivalent to a 7" diameter duct. If the sidewall is 6.5" the outlet is 8" equivalent.