Determining size of a cyclone?
#9
I'm looking to build a cyclone with my Shop Fox W1687, 220, single phase, 3HP, 3,450 rpm, 2,800 cfm, 14.4 static pressure, 12 Amp, 8" inlet, 13" impeller. 

I'm looking to vent it outside, no filter. I'm going to build it Bill Pentz style but I just can't get the dimensions figured out. I would like it to perform as it's maximum if possible, so I'd like to get it right. I was hoping someone out there might already have one built or have some basic measurements/idea that could set me on the right track? I did find BP's Design Spreadsheet. But I have no idea of the air speed and other info to calculate the proper proportions. Feelin' pretty lost here. Where's a good place for me to start with this or how to go about it? 

I did find a guy with one for sale, but not sure it's the correct size. It was on a 3.5HP unit. I had considered buying it and modifying it, except it looks kinda big. Maybe 6-7 ft tall just the cyclone body itself? Maybe not? It's all metal so that would be a decent start for modifying it, if the shell was in the goldilocks zone for mine. 

Any help out there? Thanks in advance either way.
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#10
Check oneida-air.com.  Several models both plastic and steel.  The stand alone steel units run in the $900 range.  Dimensions and HP recommendations are given.
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#11
(07-04-2018, 03:36 PM)Joe K1 Wrote: Check oneida-air.com.  Several models both plastic and steel.  The stand alone steel units run in the $900 range.  Dimensions and HP recommendations are given.

Thanks Joe! I checked, nice units there. I found outlet sizes and stuff. But no dimensions or schematics. It did give me a few leads with the comparison chart though. 

The sites I've read up on all say that the length/width of the barrel and cone are to be proportionate to the info needed -CFM, air speed etc for optimal performance. Just trying to get it dialed in best I can since I'm piping it outside. Won't really have the chance to rebuild any time soon. You know how it goes. :-)  

I'm still reading up and getting closer. Might just break down and buy an air speed gauge or something - peace of mind perhaps? ha! IDK< Not sure yet.  Happy 4th!
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#12
If you're venting outside, you could put the cyclone outside, and save some space. It's also easier to hoist and maintain it outside. Any leakage of dust goes on the ground, not into your shop.

It would be a good idea to install self cleaning blast gate right after the point where the pipe leaves the building. This keeps cold air and moisture from coming in when you're not running the blower. In the summer, I have left the outside and a planer blast gates open over night, and found the inside of the planer wet and rusting. The head and tables needed to be cleaned fast.

For venting outdoors, it's nice to have a smaller blower in the same system to use when a bigger blower is not needed. I have to pen a window for make up air when running a blower. The little blower is a 3 hp 6" inlet direct drive dust collector bolted to the wall below the big blower. The little blower collects dust from small cutters on the shaper, a dado blade on a table saw, a miter saw, etc.  I just use a 4" plastic hose for piping.
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#13
I’m installing a 5hp Gorilla pro now. I elected to keep it inside so I wasn’t throwing air conditioning outside.
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#14
(06-26-2018, 07:11 PM)SpiderDave Wrote: I'm looking to build a cyclone with my Shop Fox W1687, 220, single phase, 3HP, 3,450 rpm, 2,800 cfm, 14.4 static pressure, 12 Amp, 8" inlet, 13" impeller. 

I'm looking to vent it outside, no filter. I'm going to build it Bill Pentz style but I just can't get the dimensions figured out. I would like it to perform as it's maximum if possible, so I'd like to get it right. I was hoping someone out there might already have one built or have some basic measurements/idea that could set me on the right track? I did find BP's Design Spreadsheet. But I have no idea of the air speed and other info to calculate the proper proportions. Feelin' pretty lost here. Where's a good place for me to start with this or how to go about it? 

I did find a guy with one for sale, but not sure it's the correct size. It was on a 3.5HP unit. I had considered buying it and modifying it, except it looks kinda big. Maybe 6-7 ft tall just the cyclone body itself? Maybe not? It's all metal so that would be a decent start for modifying it, if the shell was in the goldilocks zone for mine. 

Any help out there? Thanks in advance either way.

Have you tried using Pentz's spreadsheet?  It will tell you what size cyclone you need and output a drawing of it, including how to cut the sheet metal to make it.  Inputting 3 HP for the motor outputs a 22" diameter cyclone with an overall height of 93".  

John
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#15
What he said.  ^

My Pentz cyclone is 18" dia. with a 9" dia. center tube.  It might have been made for a 2 hp blower, but I'd have to dig out the file, which I probably kept, so be sure.  I'm using 6" dia. main trunk line, which is really too big for such a small blower, but if the heavy stuff can get up the branch vertically to the trunk, it seems to carry along to the cyclone fine.  And I use it mainly for dust rather than chips anyway.
Tom

“This place smells like that odd combination of flop sweat, hopelessness, aaaand feet"
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#16
(07-05-2018, 01:32 PM)TDKPE Wrote: What he said.  ^

My Pentz cyclone is 18" dia. with a 9" dia. center tube.  It might have been made for a 2 hp blower, but I'd have to dig out the file, which I probably kept, so be sure.  I'm using 6" dia. main trunk line, which is really too big for such a small blower, but if the heavy stuff can get up the branch vertically to the trunk, it seems to carry along to the cyclone fine.  And I use it mainly for dust rather than chips anyway.

First off, my apologies for not answering sooner. I've been working out of town with no internet until yesterday. I would've tried to see if I could figure it out on my cel phone, but it didn't occur to me. I thought the thread died out from lack of interest. 

Yes, I did try the pentz calcualtor and didn't get anything. (maybe 'spreadsheet' is different?) Do you have a link to that you could send me by chance? I'm curious if your is different? Mine was asking questions I didn't have the answers to. Left frustrated scratchin' my head after that. So, I was hoping someone had something similar set up, to get me on the right track. 

I would love to put mine outside, space is becoming a rare thing inside. But there's no where to put it, or any other out building either. I considered building an enclosure outside the wall. But it would involve more than I'm able to swing right  now. My Shop Fox has two lower bags and two top bags (filters). I had considered even re-routing (separate) those to mount on the outside wall - skipping the cyclone all together for now. Then building a vented enclosure cabinet around them to protect it form the elements, birds, yellow jacket nests, etc. But again it gets to be a bigger project than I can take on, at this time. Building the cyclone will involve work too, but being a metal guy it's easier than the other options I've come up with so far. Plus my Dust collector is going to be on a Y-valve now that I only have one blower. It'll be shared with a welding fume extraction arm that I built. If I stick with the cyclone, the wood and fume (no sparks) will be easy to keep independent of each other. Building a cyclone and sharing it between the two, was the cheapest and quickest solution on a tight budget. For the time being.

On my last read of Bill Pentz' cyclone, he mentioned 18" with a 9" downspout was ideal for a 3 HP Dust Collector. I don't recall the CFM's mentioned as I think it was generally speaking? That even an inch one way or the other can dramatically effect the performance. Keeping it smaller than larger helps with velocity and separation. That's why I'm trying to get this right. Without filters, I'd like to have it optimal as possible. I'm having trouble figuring things like the air speed and flow when it's not even built yet. I'm just going with a one hose connector. Direct to the machine I pull out and hook up to it. Kind of time consuming sometimes, compared to having it stationary and ready. But it'll do well for my needs with limited space.

I'm all ears for anything more. Thanks everyone!!!!!
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