Will This Cyclone Work

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Forum topic by Kyzach posted 07-05-2020 06:46 PM 406 views 0 times favorited 8 replies Add to Favorites Watch
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8 posts in 2029 days

07-05-2020 06:46 PM

I recently purchased an old cyclone used at a cotton gin. The price was very low, so I didn’t really go over the cyclone until I got home. There are a few things about it that leave me scratching my head. First, the intake is angled up rather than down. Second, the cyclone has a choke point. It’s like a cyclone sitting on top of a cone. That doesn’t concern me by itself. However, the third point is the depth of the exhaust pipe. It extends below the bottom of the cyclone and into the lower cone. It seems to me the saw dust would be pushed to the choke point and then drop straight down, right next to the exhaust. I built a smaller cyclone for my shop vac a few years ago. I put the exhaust pipe down about 1/4 to 1/3 of the height of the cyclone and it works great. I’ve no problem with taking a torch and a welder to this to make it work. I’m curious with everyone’s opinion as to whether this will still work as is, whether I should modify it, or scrap it and buy a commercially made unit that is tailored to my needs. I’m currently using a Powermatic model 75 twin bag dust collection system. It works great, but there’s always room for improvement.

8 replies so far

View Sark's profile


300 posts in 1165 days

#1 posted 07-05-2020 11:23 PM

I’m no expert, just curious. My first thought is that size of cyclone would take a 5 to 10 HP blower or larger. Your Powermatic is a 3 HP, no? Too big for your small blower, is my guess.

Isn’t the exhaust at the top of the cyclone? And the intake is the red upward slanting duct? That makes sense to me. I can’t tell from the pictures but it looks like the duct between the lower half and upper half is quite a bit larger than the exhaust duct. Since the dust moves under centrifugal force outward, It travels between the large coupling duct into the lower with still enough centrifugal force to move towards the outwards of the lower cone. The airstream reflects back out the exhaust when it hits the end of the exhaust duct. Don’t see a problem there.

Also, it looks like the lower cone should feed into some other type of trash can. It’s not designed like a typical shop dust collector where the cone goes directly into a trash can. Just a total guess…

But I think your better off getting the Super Dust Deputy from Oneida…you might be spending a lot of time getting this to work better than what you already have.

View farmfromkansas's profile


210 posts in 419 days

#2 posted 07-06-2020 03:16 AM

Question, what is the diameter of the largest part of the cyclone? most WWing cyclones are 18” diameter. what size is the intake? And. what size is the pipe on the bottom. Maybe on the bottom you could just increase the pipe size so there is no ledge. Or try it as is to see how it works. Also, the hole for exhaust on top should be 2” bigger than the intake.

View Fred Hargis's profile

Fred Hargis

6315 posts in 3298 days

#3 posted 07-06-2020 06:57 PM

I think I’d just pass that on as scrap and find something else, sorry.

-- Our village hasn't lost it's idiot, he was elected to congress.

View pintodeluxe's profile (online now)


6175 posts in 3618 days

#4 posted 07-06-2020 07:46 PM

It needs to be engineered as a cyclone appropriate for wood dust. The design also needs to consider inlet angle, impeller size, motor RPM, and to a lesser extent motor HP.

I would say that certainly won’t work for what you want it to do.

Look at modern cyclone designs. The inlet geometry is very specific to get good separation.
You’ll find something that works for you.

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View Kyzach's profile


8 posts in 2029 days

#5 posted 07-06-2020 09:20 PM

I took some measurements of the cyclone portion of the contraption. The cyclone is 41” long, the exhaust extends 17” down below it, the lower diameter is 15”, the top diameter is 21.5”, both the intake and exhaust are 9” ID. The galvanized pipe on the top hits a pair of 45 degree elbows and continues out the bottom. I turned the cyclone right side up for a little clearer picture. I agree it’s probably a better idea to purchase a new one, but I’m going to have a go at it before I scrap it. Even though the larger section is a cone, it appears to be just a glorified barrel with a dump port on the bottom.

View LittleBlackDuck's profile


4992 posts in 1626 days

#6 posted 07-07-2020 01:03 AM

OOPS… missed the “cotton” part so my reply was out of context.

Yep, my vote for Dust Deputy…

-- If your first cut is too short... Take the second cut from the longer end... LBD

View farmfromkansas's profile


210 posts in 419 days

#7 posted 07-07-2020 02:39 AM

Probably worked good on cotton, but that is weird, just having the inlet go down to the bottom of the cyclone.
Agree, get a 6” intake SDD. Think it is a XL.

View ibewjon's profile


1758 posts in 3598 days

#8 posted 07-07-2020 01:50 PM

The proper SDD will probably cost less than modification of what you bought.

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