Upgrading baghouse filters

[J.R. Rutter]

Posting this here because I personally only monitor this forum vs the workshops forum.

I have been monitoring air quality in the shop over winter (because the shop doors are closed) and think that I should be able to improve on the Beane filter tubes that I have now. I have not been able to find and efficiency charts for the various weights of shaker felts. I'm waiting for American Fabric Filter to get back to me, but thought I would see if anyone here might know of a resource to help make an informed decision.

I know that there are other considerations besides filter material, but i have calculated the air flow across the filters to be very low compared to typical, because I originally bought an oversized baghouse as a cyclone afterfilter. CFM / SQFT is less than 10 at the absolute max that the blower could theoretically pull through the cyclone.

Not interested in cartridge filters right now. I've had too many overflows in the past and have had them blow up due to loading.

[David Kumm]

I'll be interested in the numbers too. When I was researching a couple of years ago, there were certain Am filters that outperformed Beane from a separation efficiency standpoint. What I wasn't clear on was the difference in pressure drop between the two. Given your excess sq footage of bag area, that should be less of a factor than someone with less filter capacity. Air quality depends not only on the filtration, but on how much cfm can get through the filters without reducing the cfm pulling through the machine. Dave

[Martin Wasner]

I'm 90% sure my baghouse has felt socks from American Fabric Filter. I haven't done air sampling or anything, but I don't see evidence of anything in the return side. I think the filtering ability is good.

I have trouble with the socks not releasing the light fluffy chips. We can't hold much in the hopper and we're having to beat material out of the socks. The air to cloth ratio on mine is way too high and if you've got a cyclone in front that shouldn't be a problem. I need to add a cyclone.

[J.R. Rutter]

AFF says that their 12 oz is rated for 3-4 micron, but didn't provide any data. They said that the Beane fabric is actually better. The Beane efficiency chart that I have says 50% efficient at 2.2 microns and over 95% at 4.5 microns. Still trying to gather info, but maybe chasing down small leaks on the pressure side will be the answer. I do have fine ambient dust that builds up over time.

[David Kumm]

mine are 16 lb singed inside poly. That might account for some difference. Dave

[J.R. Rutter]

I'm not sure why they quoted 12 oz when I asked for the best filtration option. Must just be their default. Here is the Beane info: http://www.maddocksgroup.com/beane_e...ane_spec_sheet

[David Kumm]

i'm running a four bag Coral 20" diameter x 8'. I don't know if that material might be heavy for baghouse tubes. It would also be good to know how the cake affects the numbers. Dave

[Mike Heidrick]

Did you get ahold of Wynn environmental and see what they offer?

Also what about Torit?

[Peter Christensen]

Have you considered enclosing the bag house and filtering the air from it with some Merv 15 /16 cartridges or HEPA filters back into the room?

[Martin Wasner]

12oz felt 6x68 tubes for mine were $13.50 a piece from AFF.

I just found the quote while I was looking for something else.

[J.R. Rutter]

Looks like 12 oz felt @ 2-3 micron < Beane fabric @ 1-2 micron < 16 oz felt w/ PTFE membrane inside @ sub 1 micron. I don't want to enclose the bag house because dealing with an overflow situation requires manually clearing up to 64 tubes.

[Martin Wasner]

I'm curious about the membrane. Who's manufacturing that and how much does it adds to the cost. Do they have it like a laminated layer, or is it a separate sock inside?

[J.R. Rutter]

Laminated layer. Tetratex(R) made by Donaldson, I believe, based on the lit AFF sent. Adds about 30% to the cost above standard shaker felt.

[Martin Wasner]

So the shop next door improved their system, and it was enough to improve your air quality? Bizarre.

[J.R. Rutter]

So the shop next door improved their system, and it was enough to improve your air quality? Bizarre.

Commercial kitchen owned by catering company who also rents it out to food trucks, etc. They had a single 6" vent duct/fan to service their hoods. Sometimes the air would actually be hazy and I could always smell what was cooking/burning. The city finally made them come up to code. The Dylos particle counter went from ~2,000 to ~200 on sub micron particles overnight. I assumed that my DC was the problem, but even with both collectors running, the base number stays about the same...