? about dust collector efficiency

[bodier62]

I have a PSI 850 CFM collector I picked up off CL that came with a plastic lower bag and an upper bag that appears to be some type of synthetic weave (not the felt type I had on a previous PSI unit of the same type). My question is: would I pick up significantly more air flow if both bags were porous?
TIA for any and all info.
Jim

[JimD]

If your woven bag is like the one that came on my delta you should switch it out for another reason. It will pass particles up to about 30 microns. So your DC will collect the big stuff that is no health risk to you but blow the little particles that can get deep in your lungs up where you can breath them. I've used the felt bags, I had them on the top and bottom, but I think it's better to go all the way to a Wynn cannister filter. You have to do a little work to get them installed but the paper one, like I have, is only a little over $100 and it gives you almost a HEPA filter trapping almost everything.

Two bags will give you a little more airflow than one bag and the type of filteration doesn't affect that all that much if I remember right. A cartridge or cannister filter will give you more air flow than any bag, however, because it has far more surface area. The lower bag being porus helps but only until it fills up.


Here is a link to what I recommend: http://www.wynnenv.com/cartridge_filters.htm

Jim

[LCHIEN]

If your woven bag is like the one that came on my delta you should switch it out for another reason. It will pass particles up to about 30 microns. So your DC will collect the big stuff that is no health risk to you but blow the little particles that can get deep in your lungs up where you can breath them. I've used the felt bags, I had them on the top and bottom, but I think it's better to go all the way to a Wynn cannister filter. You have to do a little work to get them installed but the paper one, like I have, is only a little over $100 and it gives you almost a HEPA filter trapping almost everything.

Two bags will give you a little more airflow than one bag and the type of filteration doesn't affect that all that much if I remember right. A cartridge or cannister filter will give you more air flow than any bag, however, because it has far more surface area. The lower bag being porus helps but only until it fills up.


Here is a link to what I recommend: http://www.wynnenv.com/cartridge_filters.htm

Jim

I agree with Jim's statements. A second bag will reduce air restriction but only until the bag fills up. A single upper pleated filter will have much lower restriction because its total area will be 5 or 6 times better than 2 bags, and the filtering will be much better.

[pelligrini]

Most of the info you're probably going to get will be along the same lines. You'll get a more airflow, but at a cost of adding more fine particulates to your air. I don't think it will be significant. I'd always give my felt bag a thump or two anytime I was near.

I'd put the money for a new bag into a canister. My JET-650 had a felt bag top and a cloth bottom bag. I changed out the felt for a canister and airflow increased, especially over longer periods of time. The greater surface area put off the clogging restrictions. Someday I'll get around to making a thein baffle to help with the clogging. I don't have the room for a stand alone separator.

I do wish I would have spent a little more money on a better canister (finer filtering). I was mainly concerned with chip collection as most of my work is done outside my shop. I'm doing more stuff inside now, and I do notice the small stuff building up over everything, especially in the winter when I try to seal the shop up tighter. During the summer the roof vent fan is going and the doors and windows are open.