looking for examples of short cyclone dust bins

[Bruce Seidner]

I am looking for short dust bin collectors for cyclones.

Dust and chips need to fall straight down, so for the bin to be effective it would need some active or passive way to spread the collected waste to the outside corners of the squat bin.

I have seen no commercial examples to copy and I can complicate opening a can of tuna fish. Although, my research into screw feed conveyors reminded me of our debt to Archimedes as well as how little money I have to purchase such expensive but way-cool mechanicals for moving material. I am trying to avoid excavating a basement dirt floor to create the height (digging down) needed to use a more traditional metal bin. But there is likely no way around it if I want to use my relocated cyclone in the shop.

[David Kumm]

What dimensions are you needing? Dave

[Anthony Whitesell]

I'm in need of the same thing. This is one of the hold ups to me setting up my cyclone. IIRC, I'm looking at 22" x 22" (the diameter of the cyclone body) and about 24" tall. I am trying to figure out a way to put together a box-in-a-box design because my cyclone body has a flange on the bottom of the cone and be "permanently" attached to the top of the bin. There's no flex between the cyclone body and the dust bin. My concern is sealing the door to remove the bin for emptying.

[Eric DeSilva]

Look at the JDS cyclones. Mine has a bin that is about 2' in diameter, maybe 3' tall? The debris doesn't just fall down--it still has some rotational energy, so it seems to distribute reasonably well. My bin sits under a flat metal disk that is slightly flanged, and has a rubber seal on it, and the plate is connected to the bottom of the cyclone with some flex tube. If the cyclone is off, I can lift up the top plate easily, and roll the bin out for emptying. Nothing seems to escape.

Edit--let me know if you want me to take some pictures...

[Bruce Seidner]

Look at the JDS cyclones. Mine has a bin that is about 2' in diameter, maybe 3' tall? The debris doesn't just fall down--it still has some rotational energy, so it seems to distribute reasonably well. My bin sits under a flat metal disk that is slightly flanged, and has a rubber seal on it, and the plate is connected to the bottom of the cyclone with some flex tube. If the cyclone is off, I can lift up the top plate easily, and roll the bin out for emptying. Nothing seems to escape...

That JDS is like R2D2's cousin. How cute is that?

But how much rotational energy are we talking about? I never saw what occurred inside the 4' tall metal trashcan until everything was turned off and it was full to be emptied and it was probably about 6 cubic feet of a trash can.

If there were a 2' tall 4'x8' rectangular bin, would the 64 cubic feet of space allow the dust/scrap to distribute itself to the outsides of the perimeter, leaving space in the middle for new dust/scrap to fall?

Would there need to be any other active component in such a dust bin?

I can spare 2' of height before I need to start digging down and it would be quite easy to make a box out of two sheets of whadeva that was braced to resist the vacuum and then easy to blow to the out doors. I have a spare Harbor Freight 1HP portable blower that I picked up used/cheap and rarely use. When I do it is a short run to the machine and then a roll of outdoor drain pipe heads out the garage door. Of course it has to be shaken out occasionally because of all the debris that gets stuck in the corrugation. But you can't beat the price. It is decidedly low tech but it beats the heck out of a shop vac trying to keep up with a TS. I could use something like this to empty the box periodically but use a more permanent pvc to the compost pile outside.

But it occurs to me that 64 cubic feet is a lot of space and that I was just throwing that out because 4'x8' is a standard sheet and I had the thought that it would be good to have the space to keep such a squat box clear in the center. I am unclear about the effects of the size of the bin on the efficiency or CFM of the system. For instance there is only increased CFM with a short run to the outdoors with no filter resistance. But as I am rambling I think the extra volume beneath the cyclone might add to the volume of the whole system and take away some efficiency and power from the machine side intake.

What is the effect of added volume BELOW the cyclone. Is it the same or different than ahead of or before the cyclone intake?

[Anthony Whitesell]

If you're planning a 4'x8' bin, what is your strategy for emptying it?

Does the cyclone need to be centered at the 2'x4' mark, or could it be moved to one end 2' x 2'? If you can move it to one end, then maybe you could install a bulldozer type mechanism to push the saw dust to the other end. That will also depend on you strategy for emptying it. It may help it or hurt.

[David Kumm]

The Oneida 35 gal drum is about 22"x22". I have two and have found that they are big enough to carry out to the woods next to my shop. Ease of emptying is more important than capacity to me. Dave

[Eric DeSilva]

Hmm.... I think I was reading Anthony's post about 22" x 22" x 24". The stuff in my bin seems to be fairly evenly distributed across, and when it has been recently emptied, I can see stuff swirling around in it at slow speeds. The more I think about it, the more I'm thinking it is more like 3' diameter as well. But... That said, I don't think particles would distribute evenly in a 4' x 8' space; that is pretty large. Could you rig up some kind of rake inside it to move stuff--like the compactors in garbage trucks? Given that the stuff is dropping down into the bin, however, I don't think having a large volume bin is an issue affecting the CFM...

What about just making it 4' x 4'? If you are going to blow the stuff outside anyway, keep it small and just open the exhaust and blow it out every couple times you use it... Have you thought about what this is going to do where it is exhausted too? It is going to look like it snowed out there...

[Ron Natalie]

I just keep a 55 gallon drum liner in mine (for some silly reason Grizzly has had the liners backordered for mine since before I ordered it). I guess I don't let it go that far. My wife takes the sawdust in her compost.

[glenn bradley]

I can say from experience that the spoil gets spread out to the extremes of the bin without any extra effort. My cyclone drops out an 9" piece of spiral hose about 8" long into a barrel that is not quite as tall as it is wide.

[Paul Wunder]

Bruce,

http://www.pennstateind.com/store/CYDRUM35.html

Above is what I used. 21" high X 20" diameter and 35 gallons. Well made, lockable lid and the recess in the lid bought me another inch or so when installing a port. $39

Paul

[Mike Ruggeri]

When I needed a shorter drum, I just cut down my Oneida 55 gallon (card board type drum) to the right height. Cut the bottom of the drum off so I could still use the original Oneida clamp and top. I then kerf cut a piece of 1 x2 and bent it around the bottom edge of the cut area so that the wood served as a place to secure the "new" bottom of the drum. Some screws & epoxy and I was good to go.

Mike

[Eric DeSilva]

I came back to this thread because I was realizing the "Full -- Empty Bag" line is only about halfway up my waste bin. Maybe 3/5ths of the way. Doesn't seem to give you a lot of room if your bin is only 21" high?

[Anthony Whitesell]

Hence the reason we're trying to make the bins wider.

[Thomas Canfield]

This shows a 55 gal plastic barrel that was cut down and a sight port added. The bumped up reienforcing rings ID are just about the same size as the drum OD and a little silicone calk and screws makes a tight joint allowing shortening the barrel to whatever height is needed and keep the sealable lid.

http://www.sawmillcreek.org/showthread.php?146321-Cyclone-Dust-Collector-Bin-Sight-Port&highlight=

[Bruce Seidner]

I was tossing out an extreme number to raise the question about the effect that the size of the bin has on the efficiency of the system. 4'x8' is pretty wild. But sadly, 2 feet is likely more than I really have to spare, if that. But excavating a foot of dirt is different than excavating a 4' hole of dirt and the room one would need to swap out the bins once buried in the hole. It is more than I want to tackle.

But I like those short 21" bins which gives me some confidence that I can get away with something that short.

I had been thinking of getting rid of the cyclone and just blowing everything outdoors into a large dog house looking structure with a A shaped roof and enough large mesh screen to let the dust out and keep the larger scrap in the box that I could empty later.

But I do have a huge filter bag and all the fixings to keep this contained to the shop but for the loss of room for a bin. It doesn't get that cold here. But lord the humidity in the summer is something I could do without.

So one option seems like I can build a bin that is short and wide and empty it with a blower to the dog house catcher to the outdoors. I find it a mess to try and do any emptying of a bin indoors. It more than defeats the purpose of collecting the dust in the first place.

I am not hearing much complaint or concern about short bins given the commercial example at the Penn site.

Cool beans, if I can make the room it would make sense to have several of these that could just be moved aside when full and sent to the compost after the day is done.

Thank you for the reference and the group think.

[Tom Rausenberg]

Mine is 20" tall x 14" wide x 24" deep. The air flow seems to fill in the corners first, and it fills nearly completely without any help. But I'm not sure what would happen if you made it really wide.


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[Anthony Whitesell]

Here's the answer to a lot of the questions:

http://www.youtube.com/watch?feature=fvwp&NR=1&v=8rU9iBlM2o0

I wish I had time to do stuff like this...

[ian maybury]

That's a very useful video Anthony.

I'd seen there was lots of spin still in the air in the connection hose on my system and wondered/posted about the barrel/drum issue before Bruce. Being of an engineering bent I'd say the issue on drums is that the drum is actually a functional part of the cyclone - especially on fine dust.

So far as I can tell the drum functions as a sort of attenuator/energy removal device - in that when the still spinning air and more importantly the dust drop into it they suddenly get to expand outwards. In doing so the velocity drops right down, and the dust can drop out of the airflow.

You can imagine if the drum was too small, or the hose very short, or if somehow there was heavy turbulence of the wrong sort in the drum that it might interfere with this effect, but what I'm saying is speculative. I wonder for example if the separation efficiency drops off as a drum nears being full?

You see lots of configurations of hose and drum size (Oneida etc seem to go for a very large diameter connection hose for some reason), and I've no idea what if any of these variables matters or how. I seem to recall somebody suffering poor separation on the Clear Vue forum as a result of a very short connection hose, but don't know how reliable the information is - or what other variables might have been in play.

Fibre drums seem to be a good choice for a dust container, and they come in varying sizes. Having been tipped off here of the weight issue with larger 55gal and similar drums, and rather than paying for shipping and the like I (luckily) found a local packaging supplier specialising in them and bought some there along with liner bags. They had quite a range of size choices available. Maybe you could do similar?

ian

[Anthony Whitesell]

Off the cuff based on the video, I might think that a 18" tall 36" diameter drum would work fine. I would say there center of the can is actively rotating. If the drum was too narrow, it may not work.

It also shows how the improved trash can collector works so well.

[Bruce Seidner]

I emailed Pentz who in fact describes the Bin as an active part of the dust separation dynamics of the cyclone.

I was concerned about volume, worried that this was an active parameter, like adding additional ductwork on the machine side of the system. But as long as it is sealed, the volume of the Bin has negligible effect on the system's efficiency.

The real action is in the height and shape. In Pentz cyclone design there is a low turbulence "tornado" that continues down into the bin so that a circular bin rather than a square bin makes a significant difference in terms of separation and fine dust being forced down. The question of height concerns the potential for fine dust to stay suspended and then pulled out to the filters, prematurely clogging them or passing fine dust into the air.

Some cyclones have higher internal turbulence and count on breaking up particle clumps and do their separation in the turbulence of the cyclone rather than down along the sides of a more refined cyclone design with a tighter tornado or swirl. Regardless, there does seem to be some advantage having a bit of straight ducting of 4" or so before the Bin to stabilize the tornado which continues in the bin itself.

So, with squat Bins there is less height to allow for optimal dust separation, and therefore more dust being pulled out to the filters.

The good news for me is that volume does not load or detract from the CFM of the system, so long as it is air tight sealed.

Shape makes a difference. The dynamics of the air swirling in the bin contributes to the separation of fine dust and it's being pushed to the sides of the bin, sinking, and making for cleaner air going out to the filters.

Sadly, for me, height is a factor with short Bins without a short run of duct to stabilize the "tornado" permit more dust back up and out to the filters.

I think I am going to have to dig a hole and have found 55 gallon plastic drums in town for $10 a piece. They are described as thick plastic and I can bury one in the dirt of my crawl space without concern for rust. If I can get the room for a short run of duct below the cyclone I can have room to use a removable bag and pull it out to empty. If I don't have room then I will just use the Bin as a septic tank and use a small dedicated blower and direct vent this to the outdoors when it needs cleaning. I imagine that it would not be much of a chore to flip a switch and have the Bin emptied to the garden on the other side of the garage wall. If it makes a real mess I bet running the water sprinkler would damp it down before I had too much complaint from my family.

[Jamie Buxton]

...I think I am going to have to dig a hole and have found 55 gallon plastic drums in town for $10 a piece. They are described as thick plastic and I can bury one in the dirt of my crawl space without concern for rust. If I can get the room for a short run of duct below the cyclone I can have room to use a removable bag and pull it out to empty. ...

A 55 gallon bag of sawdust is pretty difficult to handle, if the bag is the same thickness as the typical garbage bag. Particularly if it is filled with sawdust, which packs much more densely than planer shavings, it will be heavy. Also it is bulky, and doesn't really have anyplace to grab it. Or another way to say it is that if you grab it at the top, that's the only place you can. Grab it anyplace else and you're likely to put your finger through the bag. And if you do manage to pick it up, what do you do with it? That's too much volume for most residential trash systems. I think you'd be better off with your original idea -- more like 30 gallons.

[Anthony Whitesell]

Not sure my gut feelings that I agree with all of that. I still have a feeling that some of the efficiency lost in height may be able to be recovered by increasing the diameter. There are obviously limits to how short and how fat you can go before the efficiency drops or is unrecoverable and the increase in size has a neglible effect on performance.

I guess I'm going to have to rethink my square drum design. I don't have the option of digging down and I don't have the option of flex on the bottom of the cone. As another thread was mentioning. I'm still worried about the noise and noise increase when I fire up the cyclone. I don't know if it will be too much for the basement shop.

[Alan Bienlein]

I just shot a video of my dust bin. I start with all gates closed and then open one at a time till I have three blast gates open and then I close them all again.http://www.youtube.com/watch?v=ufolmCfvDXI

I hope this helps. By the way it's a 5hp cyclone with a 16" impeller with a 8" intake and 8" flex into the dust bin. Dust bin is a 55 gallon drum that I shortened by 7" in height.

[ian maybury]

Thanks guys, dead interesting stuff there. It's clear at least that the bin and its connection to the cyclone needs thinking about, and that it's a n important variable in the whole deal....

ian

[Anthony Whitesell]

If it is spinning around in the bin that much, then I definately think that a larger diameter bin would help the separation by helping to decrease the velocity. We're looking very closely at the principals behind Phil Thein's improved trash can collector.

[Alan Bienlein]

I've noticed since I've added that plexiglass window on the drum that the more blast gates I have open the more it swirls around in the dust bin.

Is it normal to swirl that much or is there a problem I might need to address?

[Bruce Seidner]

I think your demonstration suggests that it is both normal and something that has received scant and inadequate attention. Great video. Thanx.

[Phil Thien]

I think I am going to have to dig a hole and have found 55 gallon plastic drums in town for $10 a piece. They are described as thick plastic and I can bury one in the dirt of my crawl space without concern for rust.


Hmmm.... Man brings home 55-gallon plastic drum, and then starts digging hole in crawl space (perhaps in the evening). Better hope your wife doesn't pick this time to go visit her sister for a week, otherwise the neighbors are going to get pretty darn suspicious.

[Anthony Whitesell]

I think I am going to have to dig a hole and have found 55 gallon plastic drums in town for $10 a piece. They are described as thick plastic and I can bury one in the dirt of my crawl space without concern for rust. If I can get the room for a short run of duct below the cyclone I can have room to use a removable bag and pull it out to empty. If I don't have room then I will just use the Bin as a septic tank and use a small dedicated blower and direct vent this to the outdoors when it needs cleaning. I imagine that it would not be much of a chore to flip a switch and have the Bin emptied to the garden on the other side of the garage wall. If it makes a real mess I bet running the water sprinkler would damp it down before I had too much complaint from my family.

Question. If you put the barrel in a hole, how are you going to get it out from under the cyclone to empty it? That's going to be a pretty big (wide) hole.

[Bruce Seidner]

Well, granted, it is a sort of madness to be digging holes for plastic barrels in the basement but I don't think it will lead to an episode of CSIV. I picked up my barrel today and it is a beauty. The plan is to use it as a bin that gets emptied by a portable blower I have that will vent directly out the side of the foundation of the house to the side yard garden. I had planned about a year ago to do this but was able to put this off with an alternate placement. But moving things around again requires that the cyclone and bin be out of the shop and in another area. There are advantages. It will be much quieter sequestered behind a wall, but I will have to think about and remember to empty it regularly. Using a 4" PVC flexible duct placed down into the bin periodically and switching on the 1hp portable blower direct vented to the outdoors through a fixed 4" PVC pipe should not take that long and it is certainly not back breaking work to flick a switch.

Now I just have to rent a 2cycle post hole digger and try not to make too much of a mess. But yes, my wife will feel nervous. Not for her safety so much as for my sanity. I will try to explain that this is all less expensive than golfing and it keeps me around the house, albeit in the man cave.

[Ben Hatcher]

Does your sump pump run very often? I hope you don't end up with an accidental pond.

[Bruce Seidner]

That was one of my gardening life time achievements of 20 years ago. I raised all the beds, sloping away from the house and dug a French drain. There is lots of water that comes down the hill towards the home and garage, but it is diverted and follows the path down and around. Now, if I can only figure out how to cut truly square pieces of wood and keep the dust out of my lungs this will be the hobby life time achievement award.