Cyclone filter - a better way???

[Ken Krawford]

I just spent 90 mins. with 2 compressors and a shop vac blowing out the filter cartridge from my cyclone and even then I didn't feel that it was very clean.
Is there any way to employ some sort of disposable pre-filter and spare the cartridge so much dust?
Does anyone else have a different method of dealing with this problem?
Thanks for your insight.

[Mark Beiting]

Ken,
This might not help much, but here's what I do. I don't have close neighbors, so when the breeze is blowing in the right direction I take the filter "out back", hook up the hose from my leaf vacuum to the filter, and while that is running I blow the filter thoroughly with my back pack blower. It takes about 5-10 minutes and makes a nice dust cloud, but the filters feel like they are 5 or 6 pounds lighter after. The frequency on cleaning is directly proportional to the amount of time that my drum sander is being used. That thing produces lots of fine, filter clogging dust!

Cheers,
Mark

[ian maybury]

Hi Ken. I can't resist asking which cyclone you have, and what sort of work you mostly do. Although all cyclones will pass some very fine dust, and power sanders tend to produce a lot of it. Do you have a single or a double cartridge set up?

I guess one way of making the cleaning of cartridges a bit easier may be to install them in a cabinet so that the airflow is in the originally intended outside to inside direction. Cleaning is still going to be a bit messy, but somewhat easier. The down side is that it takes up more space, and that since the cabinet is under positive pressure it's very important that it doesn't leak - or it will let dust escape. You can add a coarse over sock in that situation to prevent coarser chips getting caught in the filter, but it won't stop fine dust..

Somebody may have experience, but i've not hear of using a pre-filter per se. It's got to be fine enough tos top the dust, in which case it'll need cleaning or throwing out too. Something like a bag might be an option, but the trouble is that again it has to be very fine to stop the dust, may be rather large if it's to have enough area, and will likewise be a PIA to clean.

The secret to a good long filter life (apart from minimising the dust they see) is also to ensure there's plenty of filter area….

[Roy Harding]

I finally gave up trying to keep the filter clean, and now vent directly outside. This may not be an option for you if you live in the city and have neighbours close by.

I used to clean the filter with my air compressor - but as others have noted that's not necessarily a good option. I have a drum sander which is used a LOT, so clogging of the filter was a major pain. At one point, I thought of putting a second cyclone between the current one and the filter, the idea being to let even more particles drop out of the stream before hitting the filter - but I never got around to trying it, and I'm not sure how well it would work. As far as a "pre-filter" goes, I also contemplated putting some pantyhose, or something similar into the exhaust stream prior to it hitting the filter, but gave that idea up as such a "pre-filter" would clog up even faster than the regular filter.

In short - I don't have the precise answer you're looking for, but if at all possible, I'd encourage you to think about venting outside (I haven't experienced any catastrophic heat loss since doing this - some, to be sure, but not enough to worry me, and I live in northern Canada. My dust collector is on often, for 5 - 30 minutes at a time, but does not run all day).

[Peter Aeschliman]

I finally gave up trying to keep the filter clean, and now vent directly outside. This may not be an option for you if you live in the city and have neighbours close by.

I used to clean the filter with my air compressor - but as others have noted that's not necessarily a good option. I have a drum sander which is used a LOT, so clogging of the filter was a major pain. At one point, I thought of putting a second cyclone between the current one and the filter, the idea being to let even more particles drop out of the stream before hitting the filter - but I never got around to trying it, and I'm not sure how well it would work. As far as a "pre-filter" goes, I also contemplated putting some pantyhose, or something similar into the exhaust stream prior to it hitting the filter, but gave that idea up as such a "pre-filter" would clog up even faster than the regular filter.

In short - I don't have the precise answer you're looking for, but if at all possible, I'd encourage you to think about venting outside (I haven't experienced any catastrophic heat loss since doing this - some, to be sure, but not enough to worry me, and I live in northern Canada. My dust collector is on often, for 5 - 30 minutes at a time, but does not run all day).

I agree with Roy. Even the best cyclones will pass the super fine dust and clog filters. A pre-filter is also a filter, so it will also clog eventually.

If you can't vent outside, the best you can do is find a way to increase the time between cleanings and reconfigure your setup so that the cleaning process itself is easier.

To increase the time between cleanings, it's probably a simple matter of increasing your filter surface area via bigger or more filters.

To make cleaning easier, you could do something like Ian proposed, or change your technique (the leaf blower for example).

But ultimately, the simplest solution is to vent outside.

[Ken Krawford]

Thanks everyone for taking the time to respond. This was one of those posts where is suspected that there was no "free lunch" but secretly hoped that someone had developed an ingenious way to solve my problem.
Venting outside is totally out of the question. I think from now on I'll set reminders to clean the filter more frequently. I do have a decent leaf blower. Next time I'll give that a try.

[Ken Krawford]

Ian, I have a cyclone based on the Bill Pentz design that I purchased as a kit many years ago and a single cartridge filter. I have all the typical stationary tools found in most shops but suspect that my Performax 16-32 is the culprit with the fine dust reaching the filter.

Hi Ken. I can't resist asking which cyclone you have, and what sort of work you mostly do. Although all cyclones will pass some very fine dust, and power sanders tend to produce a lot of it. Do you have a single or a double cartridge set up?

I guess one way of making the cleaning of cartridges a bit easier may be to install them in a cabinet so that the airflow is in the originally intended outside to inside direction. Cleaning is still going to be a bit messy, but somewhat easier. The down side is that it takes up more space, and that since the cabinet is under positive pressure it's very important that it doesn't leak - or it will let dust escape. You can add a coarse over sock in that situation to prevent coarser chips getting caught in the filter, but it won't stop fine dust..

Somebody may have experience, but i've not hear of using a pre-filter per se. It's got to be fine enough tos top the dust, in which case it'll need cleaning or throwing out too. Something like a bag might be an option, but the trouble is that again it has to be very fine to stop the dust, may be rather large if it's to have enough area, and will likewise be a PIA to clean.

The secret to a good long filter life (apart from minimising the dust they see) is also to ensure there's plenty of filter area….

[Steve Peterson]

All I can think of is a spare filter so you can swap them while you vacuum the dirty filter. Even if you assume a 90% effective cyclone, only 10% of the fine dust will transfer back to the new filter.

Steve

[ian maybury]

Ta Ken. The Pentz cyclone is normally pretty good, but they all pass some fine dust.

As before a dual filter cartridge set up would take a lot of the heat off i suspect - running a single cartridge with a drum sander doesn't sound ideal. (not enough filter area)

The other point is that exhausting outside (even if only for short periods while running the sander) may be less of an issue than you think if you keep the cyclone in line. In that the dust going outside should be fine to invisible, and in fairly small quantities.

I have my Pentz style system set up so that i can do this, but haven't yet tested it as i unthinkingly fitted an 8in aluminium blast gate on the fork in my fan exhaust (one leg goes outside, one to the filters) and the thing leaked dust like a sieve into the shop. (the gates fit very poorly on that type) So i had to temporarily seal it up with silicone pending a change to a proper sealed diverter valve.

Maybe somebody like Roy or Peter already venting outside can comment on how much dust they see outside?

[Peter Aeschliman]

I have a 16/32 drum sander and an ebay cyclone with a 3 hp grizzly motor and impeller. I'll bet my cyclone isn't nearly as efficient at separation as Ken's Pentz design. I can't see any dust outside at all. Surely there is dust blowing out of the shop, but I don't really see any traces of it.

[Roy Harding]

I don't see much dust at all with the naked eye. However, it's definitely there - the cement and siding near the exhaust is discoloured, and in the winter the snow in that area is noticeably dirty.

[William C Rogers]

I have the eBay cyclone with a 3hp Jet 1900 DC (14" impeller). I had just recently set it up venting outside. I ran my Supermax 19-38 for about 6 hours making 7 cutting boards. Very little dust outside. Here is the second drum that has one 8' board run through the jointer on the bottom with the rest being from the drum sander.
image.jpg

Here is what I saw outside. The exhaust is right near my trailer fender. I ran my finger on the fender to give an idea of how much was there.

image.jpg

The eBay cyclone does a darn good job.

[Martin Wasner]

How about a bag house with an auto shaker?

[Chris Parks]

Make sure you have no air leaks in and around the collection bin and its connection to the cyclone.

[Ken Krawford]

My problem with exhausting outside is that my cyclone sits in the corner of a poured concrete basement and the top of it is right at ground level. I'm not about to cut a 6" hole through the band of my house. We live in cluster homes and my neighbor is only 20 ft away.