Air cleaner pics

[Tom Andersen]

Todd:
The bag filter is of type 24X20X14 inch Vee Bags with loops, part Number 242014VBL, about 50$ ea, available only in two-packs.

Al:
My filters are upstream, i.e. on the suction side. I believe that is what everybody does, because it keeps the fan and the blades clean. I agree with you that a somewhat smaller fan than mine would have been better due to size and weight considerations.

Jim:
The quality of your box is really impressive! I believe that axial-flow fans are less capable of overcoming a pressure drop from filters, so you may have less flow than with a comparable radial-flow squirrel-cage fan. Anyway, your air cleaner is surely fine.

[Jim Fox]

Yeah Tom, the backflow of air is minimal, but I know it happens as I see the fans moving.......albiet not a lot.

[Tom Andersen]

Yeah Tom, the backflow of air is minimal, but I know it happens as I see the fans moving.......albiet not a lot.

My comment was mostly related to the characteristics of axial-flow fans vs radial-flow squirrel-cage fans. I believe that the squirrel-cage fans have a "stiffer" characteristic, so that they maintain higher air flow with a pressure drop.

[David Epperson]

Tom. Not to be nitpicky, but in the situations where I've seen "bag" filters like that (as pistured in #6) used they hang verticaly with airflow from below. As such yours looks to be sideways and reversed. But the applications I'm familiar with are industrial baghouse filtration and sandblast cabinet filtration, on those you can "bump" clean the bags. The big baghouse filtration units actually use a reverse blast of air (High intensity/short duration) to clean each bag one at a time during use, the smaller ones use a simple shaker bar to "disturb" the dust layer while the unit is shut down.

[Tom Andersen]

Tom. Not to be nitpicky, but in the situations where I've seen "bag" filters like that (as pistured in #6) used they hang verticaly with airflow from below. As such yours looks to be sideways and reversed. But the applications I'm familiar with are industrial baghouse filtration and sandblast cabinet filtration, on those you can "bump" clean the bags. The big baghouse filtration units actually use a reverse blast of air (High intensity/short duration) to clean each bag one at a time during use, the smaller ones use a simple shaker bar to "disturb" the dust layer while the unit is shut down.

Thanks for you comments. You are right, it would have been nice to use bag filters that can be cleaned. I couldn't find any that would fit into my small box and also clean the air to below 1 micron. If you or anybody else knows where to buy them, I would be very interested.

[Todd Hyman]

Tom. Not to be nitpicky, but in the situations where I've seen "bag" filters like that (as pistured in #6) used they hang verticaly with airflow from below. As such yours looks to be sideways and reversed. But the applications I'm familiar with are industrial baghouse filtration and sandblast cabinet filtration, on those you can "bump" clean the bags. The big baghouse filtration units actually use a reverse blast of air (High intensity/short duration) to clean each bag one at a time during use, the smaller ones use a simple shaker bar to "disturb" the dust layer while the unit is shut down.

David,

Can you tell us where you can get these at?

[David Epperson]

I'll look into it and see if I might be able to find out. I never had the responsibility of ordering them (the filters), just cleaning and maintaining the systems.

[David Epperson]

They looked very much like the filters you have pictured, a bit longer perhaps. But the key thing was that the bags were attached to the top of the frame and allowed to "hang" down. The "dirty" air was ducted in from the lower section of the frame through the filters and out the upper section. So gravity was used to "clean" the bags. Granted, these were also never removed for cleaning either, but the majority of the dust burden would fall off due to gravity(into an open area below the bags) when the system was shut down and the bags were shaken. This was done in most cases with a simple round bar arangement that went between the bags with a handle attached. Shake the handle to beat the bags. Collect the fines at the bottom and discard.

The industrial bag house filters were 6 to 8 foot long and 6" to 8" in diameter of an eggshell filter media cloth around a steel wire frame, on a 10" to 12" spacing - with around 120 bags per filter house. Each bag had a reverse flow blast nozzle (1-1/2" quick exhaust valve at 110psi) at the top which was "fired" periodically, one bag at a time, on a timer. to knock the gross buildup down. This way they were "cleaned" even during active service.
But these baghouse collectors also had 50 to 75hp blowers on them too.

[Benjimin Young]

Tom, re lifting the heavy assembly. Perhaps you can rent a drywall lifter used to hold drywall sheets on the ceiling while you screw them in place.

Ben

[Darrick Hartman]

That probably is possible, never thought about that. LOL

Something to look into!

Those look like 120V fans, not the 12V fans you'd find in a computer. More likely these were used in a big plotter. If they were 12V fans, you could easily put a resistor inline and slow them down. You might be able to put a variable speed fan control, as long as the amp draw doesn't exceed the switch...most of those are designed for small ceiling fans.

I am in the process of setting up my shop in our basement. We bought the house in June (06) and did alot of the brute construction type work over the summer and into the fall. I'm finally ready to get started on the drawers and doors for the bathroom vanity. Before I start doing woodworking here, I definitely want to set one of these up (the wood working room is in the basement).

The previous owner did alot of wood working in this house. NO dust collection at all! We are still wiping up dust any time we touch a piece of duct work, pipe etc in the ceiling.

I was having a hard time finding the compact fans (at a reasonable price), so I opted for duct fans from Menards. 250 cfm 6" fans were around $25. I hope to get something assembled in the next week or so.

Thanks for sharing the ideas.

Darrick