Help with dust collection design
Here is a picture of my dust collection seperator. I made it out of a garden cart so i could just wheel the dust out of the basement after disconnecting from flex lines. I installed some internal baffles to slow down wood chip speed so they would drop out. The dust collector sucks the whole box clean! I thought my CFMs would have dropped due to lousy duct design, but maybe bc the box is right next to the collector it gets the maximum 2500 CFM’s from my 3 HP grizzly. Is there any hope for this design? What do you think i need? More baffles? A screen of sorts? Scrap box and build cirular cyclone type? Any ideas would be appreciated.
Kelvin
Replies
I have one I made from a 44 gallon Rubbermaid trash can. But, my only intent was to keep stuff like chunks of wood, screw drivers, nails, screws, etc from hitting the impellors of the DC. All but the very dense stuff gets sucked right on through mine. I only open it to retrieve stuff that shouldn't have gotten sucked up.
In commercial operations, it is my humble opinion that the only reason they have a separator is to catch the dust before dumping out the shaving onto the ground. If your trying to catch all, then why have a separator other than to catch stuff that might damage the impellors??
PlaneWood by Mike_in_Katy
PlaneWood
Hi There,
I have been researching dust collection for sometime and I have to say that I can not see any chance for your system. By far the best way would be to build a cyclone separator. I have included a link to Bill Pentz site this site is amazing and should give you not only the answers you need but a great deal of background to dust exstraction.
http://cnets.net/~eclectic/woodworking/cyclone/Index.html
Hope you find this of use. Let's know how you get on
Ed
I guess i don't understand why the cyclone lids that come with some DC's work when they are merely a hose going in and out of a 33 gal. trash can. I had a 2 hp grizz that worked just great with that cheap plastic "cyclone" seperator. Whats the big difference? Is it really the way the hoses enter at angles to each other making the chips twirl? Or the smaller CFM's maybe? I'll look at Penez site that was mentioned, but i don't understand why the big chips don't fall out.
One of the main reasons why those cyclone separator lids work is the way they create and use centrifugal force. It as little to do with the CFM. What happens is that the dirty air enters at the outer edge of the container and spins under centrifugal force and the debris then gets thrown out of the air stream. The design you propse does not create centrifugal force. Better than one of those lids is a proper designed cyclone as described on the pages I sent you the link for. These are much more efficient that the bucket type separators due to the fact that as the air enters the cone section of the separator the air is forced to soin fast thus throwing out more bebris. This is a very simplified explanation but I hope it helps. I have built my own Cyclone a mini one, scaled down from the one on Bill Pentz site. I can honestly say I have been using it for about 2 months and already I wouldn't be without it. Don't be put of about the construction it is very simple. Then are all the best ideas.
Ed
Kevin -
I did the lid like in the attached pic. The elbow points around the inside edge of the trash can.
PlaneWood by Mike_in_KatyPlaneWood
Kelvin:
Go to http://www.woodmagazine.com and they have an entire forum dedicated to dust collection systems. There are some very knowledgeable folks on that forum that can help you.
Roger
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