Is this normal?

A

AlanBienlein

New member
I just read in another forum about dust bin size and it's affects on separation. It got me to thinking so I went out and shot a video of mine in operation with all blast gates closed and then proceeded to open one at a time till three of them were opened after which I closed all three.Here is a link to the video.
http://www.youtube.com/watch?v=ufolmCfvDXI&context=C24af8ADOEgsToPDskIeRIxR2TqpzMkpq0t4V1_k

My cyclone is 20" in diameter with a 16" impeller and 5 hp leeson motor. I have also checked for leaks at the dust bin.

My question is is this normal for the dust in the bin to swirl this much?

Is there anywhere else I might want to check for leaks if this isn't normal and a leak could be causing this?
 
I run a 2hp airfoil impeller on my DIY 18”; the CV gives about 25% more air flow but that shouldn’t make much difference. I have a 6” Plexiglas tube into the bin and can see the dust and chips circulate like your video but they don’t come back up into the cyclone. The air is spinning but the cyclone should be sucking out clean air just below the cyclone outlet. If you have a bin leak, you might be able to see some dust being sucked up into the cyclone and your filters would plug up fast. I don’t see how the bin size could have any affect on the separation.
 
I shot the video because others were wondering what was going on in the dust bin. I was curious also.

They were wondering how short they could make the dust bin and not affect separation efficiency.

I know when I remove the lid on mine to empty it there is a fine cake of powdery dust evenly adhered to the inside of the lid and on the inside of the barrel above the dust chips. I figure if there was a leak there you would see visible bare spots from the air being sucked in at that point.
 
Alan,
I see in the photo gallery where some have offset the bin with respect to the cyclone so the hole in the lid is off to the side. It may be important to keep the bin centered so the rising air doesn't re-entrain the swirling dust. Thanks for the video, I've often wondered about the air currents in the bin.
bababrown
 
I have my bin, a 30 gal trash can, inlet offset by 2.5 in. in to get it closer to the wall and doesn’t seem to make a difference. As the bin fills, the dust is thrown to the outside edge of the bin and fills in a concave form until it gets to the top and then fills in until it starts to come up the tube. Then it will fill evenly across the bin to the bottom edge of the bin inlet tube that extends into the bin a couple inches.
Will it make any difference on how short the bin is? I don’t think it would, the cyclone should be dumping all the dust in the bin at the cone outlet and not picking up anything.
 
My dust bin has a clear plexiglass lid. See http://www.clearvuecyclones.com/Bullentin/attachment.php?attachmentid=361&d=1302550884 .

My clone has been in operation for just over ½ year now. I can tell you that is normal to see lighter materials being picked up from the top layers of the bin-detritus and swirled around inside the bin.

I’m not concerned that any of it is re-entering the cyclone and getting to the filters.

Twice I’ve inadvertently had my floor sweep port suck up a piece of very thin plastic wrapping. The first time, I saw the plastic swirl down towards the bin opening, then fly up the center tube, pass through the impeller and disappear into the filter stack. The second time, I managed the shut off the power before the plastic was sucked up the center tube, and it dropped into the bin. This second piece of light weight plastic orbited inside the bin (never re-entering the cyclone) for several months before I finally filled (well about 3/4 full) and then emptied the bin.

I too have noticed that the amount of material that swirls in the bin changes with the number of ports open. With all ports closed, there is virtually no swirling. Amount of material picked up and swirled in the bin, thus, appears to in proportion to air flow through the system.
 
You must log in or register to reply here.
Back
Top