some general dust collection questions

Carol Reed

In Memoriam
Messages
5,533
Location
Coolidge, AZ
I read about all these dust collection and cyclone projects so that I am interested in pursuing a more sophisticated system than shoveling stuf out the door and then turning on the leave blower.

So thinking in a linear fashion - from the mess to the trash can.

Pick-up via pipe or hoses, maybe with gates near at hand. Then to the cyclone which separates the dust from the heavier stuff. Then to the bag or can to be hauled out for disposal. Right so far?

Here are the questions. The can under the cyclone collects what, dust or "stuff"? Does the cyclone come "before" the vacuum pump and filter?

Do the fine micron bags go on the collection (bag or can) end of things? And the reason for the fine micron bags is to return clean air back into the shop area because it has been heated or cooled and one doesn't want to pay for more unconditioned air?

Can someone sketch up a linear 'drawing' of how the mess is gathered and separated and disposed?

Please clarify my thinking in this regard. Thanks!
 
Carol,

Those of us who have built a DC system will have a lot of opinions about what, how and when you need to do whatever you're trying to accomplish ultimately with your system. After a lot of research, I went with an Oneida cyclone. I got the larger duct and all of my wyes from them and bought smaller 4" and 5" duct locally.

One of the most comprehensive sources of data is the Bill Pentz website. Google Bill Pentz dust collection and you'll find it.

You mentioned sweeping dust and chips out the door. I placed two floor sweeps in my shop to aid in picking up stuff I can sweep. I just open the gate to the floor sweep and it grabs everything I sweep near it.

I have 5" duct running to a point near most machines, then reduce it to 4" to match the port on the machine. I have found this to be very adequate.

I'm sure others will chime in with additional input.
 
Carol'

If the cyclone is is designed correctly then virtualy all of the dust and shavings should end up in the collection drum with almost nothing in the filters. There are systems out there to fit your needs and price range.

When I came acroos Stu's website it got me in gear to do something about my dust and allergy problems. I researched and for me found the most useful info on Bill Pentz's website. For me at the time I couldn't afford to buy a complete system and the clearvue was still out of my price range. That's why I opted to build my own. Of course a couple of months after I finished the clearvue went on sale but oh well.

I converted all my machines to 6" ductwork and couldn't believe the difference it made. The most remarkable was my table saw. I no longer have a rooster tail of dust coming off the back of the blade and I don't even have any overhead dust collection for it. I still need to add a floor sweep but 2 of my drops reach the floor with the flex so its not high on my priority list.

I spent $1200 total on the system I have now which I think is a bargain but I did build evreything myself. WhenI say everything I mean the 45 degree y's, the blast gates and the ccyclone and blower housing itself. I even had enough material left over to build a mini cyclone for my shop vac.

Best I can tell you is to decide what you want to accomplish and see what fits your needs.
 
Carol, that which drops out of the cyclone is the heavier particles. Depending on the size & efficiency of the cyclone, that may be only large chips or (with a really good cyclone) most of the dust as well, passing only the real "fines" on toward the bags.

A DC system including a cyclone is laid out thus:

Pickups
Blast gates
Hose/pipe
Cyclone
Hose/pipe
Blower
Bag system (low-micron high, plastic low... or ordinary bags top & bottom)

The fine low-micron bags are there - as you suspect - to return filtered air to your shop while keeping those "fines" (the most hazardous part of the dust) out of your lungs.

Note that a cyclone is an optional part of the system - if you're not terribly concerned with the bags filling up fast, you can build a chip separator without much trouble from plywood; it'll drop all the heavier bits out as would a cyclone, passing most of the dust to the blower & bag system. That arrangement makes it a two-stage DC system, and it's really handy for those of us with metal shops incorporated into our wood shops... the separator box drops nearly all the metal swarf out where it can be collected easily.
 
Thanks Guys. Tim has the specific information I was looking for.

I have been on Bill Pentz' site and marvel at all the information.

But I have a unique situation. My major stationary tools are in a cargo trailer. Can't use them unless the back door is dropped down. That means I am automatically 'vented' to the outdoors. But it can get pretty "thick" in the trailer if I am making repetitive cuts. I'd want a portable pick-up on the table saw, the chop saw and the band saw as needed.

My biggest PITA is cleaning the filter of the dust vac when I vacuum the trailer or when I run the Performax sander. I am not concerned with venting clean air back into the shop because the shop is an open carport or an open trailer backed up to the carport.

Someday, maybe, another dedicated building, but not soon.

So if I understand this correctly. I put a cyclone in line before the vacuum motor. If I use nice big garbage cans already lined with the garbage bag, my clean up is at a minimum. And the filter is not a royal pain to clean.

Am I good to go?
 
Dust Collection

Having worked with cyclones for the last 45 years, I can tell you that they will NOT collection the harmfull fine saw dust. The cyclone can be replaced with a simple knock-out box with internal baffles to collect the relatively big stuff (much cheper and simpler). DUST will still need to be collected with high efficiency bags. Cylones will NOT collect sub micron harmful dust irrespective of what vacuum designers will have you believe.
 
Top