dumb question about cyclones

[Thomas L Carpenter]

I don't have a good handle on why so many use a cyclone with their DC equipment. The nearest i can figure is it's easier to dump the collected saw dust. What am I missing?

[George Makra]

Cyclone separators are an old technology that converts velocity into centrifugal force.
So any particles in the air stream will move to the cyclone walls and precipitate out the bottom of the separator into a collection bin.

[Matt Schrum]

The geometry of the cyclone helps separate out the particulate so your filters don't have to do as much work-- you won't clog your filters up as fast (or at all, depending on a few things). There's a bit more to it, but that's the biggest feature.

[Richard Coers]

They take the dust out before the filter. Filter life is dramatically increased. That means full suction is maintained much longer!

[Frank Drackman]

I asked a similar question a few weeks ago. Many said that the cyclone keeps your filter clean, which keeps the velocity up. Loss in velocity means less chips/dust moving through the system.

I haven't installed a cyclone yet but I blow compressed air into the filter every morning.

[John K Jordan]

Sounds like a great question to me!

As others mentioned, the separation of even the very fine dust from the air is incredible, especially with a long-cone cyclone. I've had a 5hp ClearVue running for 4-5 years now. Not only is the suction very powerful it puts even talcum-fine dust in the bin. Using a laser particulate monitor there is almost nothing getting past the filters. The filter stack has a cleanout box at the bottom but there is almost nothing there and the filters seem clean.

I understand a shorter cone cyclone doesn't separate as well but is still probably worth using. I've never tried one for comparison. This is the first DC I've had other than a hooking a shop vac to the bandsaw.

One downside is the thing is so loud I'm glad I built a sound-reduction closet for it.

JKJ

[Bill Jobe]

They also prevent the chips from going through the impeller.
Didn't see it mentioned.

[Steve Saah]

I got one for.mine and was shocked at the dramatic improvement in the suction and very rarely have to empty or clean the filters. Not much gets past the cyclone and makes emptying a breeze!

[Ole Anderson]

And to keep big items from impacting the impeller on a bagger, there is usually a grid to catch things like offcuts and tape measures. That grid also catches long stringy material like comes off a planer. That will cause a blockage. And frustration.

[Jim Dwight]

with a cyclone you do not need the grate in the impeller inlet which is an obstruction to the airflow. I also have omitted the filter entirely and just exhaust outside due to the cyclone removing nearly all the dust. There is no noticable buildup of dust outside.

But the main thing is to greatly reduce the required filter cleaning.

[mark mcfarlane]

... Not only is the suction very powerful it puts even talcum-fine dust in the bin. Using a laser particulate monitor there is almost nothing getting past the filters. The filter stack has a cleanout box at the bottom but there is almost nothing there and the filters seem clean..

FWIW, I get quite a bit of dust in the sub-filter cleanup box (and in the filter itself) with my 5HP Dust Gorilla Pro. I have to clean the filter and cleanup box every time I empty the 50 gallon drum. Maybe it's because I have a drum sander, or maybe I am letting the dust bin get too full. Either way, it is a PITA.

[John Gornall]

Mark, I think you may have an air leak somewhere. I've been using a V3000 for about 10 years connected to a single machine which produces fine dust. I don't use the filter and exhaust outdoors. I have never seen a trace of dust past the cyclone. I was advised to be carefull when assembling the V3000 to be sure it was well sealed, that dust past the cyclone was the sign of an air leak.

[mark mcfarlane]

Mark, I think you may have an air leak somewhere. I've been using a V3000 for about 10 years connected to a single machine which produces fine dust. I don't use the filter and exhaust outdoors. I have never seen a trace of dust past the cyclone. I was advised to be carefull when assembling the V3000 to be sure it was well sealed, that dust past the cyclone was the sign of an air leak.

Thanks John, I'll check for leaks. I guess I need to go buy some punks from a local fireworks supply. It could be the seal on the 55 gal drum, and I do reuse the bags a couple times.

[Thomas L Carpenter]

Thanks all for the replies. I have a 15 year old HF DC without a cyclone and it works just fine for me. I clean the original filter bag every time I empty the bottom bag and i still have plenty of flow so "if it ain't broke don't fix it" applies for me.

[mark mcfarlane]

Thanks all for the replies. I have a 15 year old HF DC without a cyclone and it works just fine for me. I clean the original filter bag every time I empty the bottom bag and i still have plenty of flow so "if it ain't broke don't fix it" applies for me.

Thomas, one problem with bag-based dust collectors is the bags let the finest (invisible) dust pass through the bags. This fine dust tends to stick deep in your lungs and doesn't come out.

If you want a clean looking shop, the bag systems are perfect. If you want clean lungs a cyclone DC with a HEPA filter is a better choice.

For reference, the Harbor Freight DC I just looked up online filters down to 5.0 microns. The Clearview filters down to 0.5 microns.