Non-cyclone dust collection idea

[Richard Kagen]

I have what I now know is a 1 hp Delta (AP400 650 CFM)“chip collector/fine dust generator.” From what I am reading, I am actually better off not using it at all as the 30 micro bags blow all of this fine dust out every time it is turned on.

I do not have the budget, ceiling height or inclination to buy a cyclone. I also can not vent directly outside for a heat and cooling loss perspective it would be a problem 50-70% of the year here in the Boston area and would likely upset the neighbors and be illegal.

So I have been noodling this problem for a bit and here are my thoughts (drawing attached)

1) build a large sealed plywood and dimensional lumber frame box
a. Big enough to roll a 2hp 30 micron DC into with 24” of open space on the top
b. Removable front panel with 6-8 wing nut/screw knob/ “t” nut in wooden cleat hold downs
c. Observation window in front panel
d. Clear vinyl tube “u” as a water gauge to monitor internal pressure.
2) Seal the duct exit
3) In the top, hang one or more cartridge filters by sliding onto and centering them on 2 pieces of pvc pipe passing thru and sealed into the sides of the box to filter the < 30 micron dust laden air output from the DC as it exits

Here are my thoughts on the advantages of this approach:
1) Relatively inexpensive:
a. I can shop cartridges and design around their size
b. I can build it and test it using my existing 1hp DC
2) Quiet as the box should insulate the sound
3) Plenty of interior air flow to keep the motor cool
4) Watching the internal pressure in the box should indicate the condition of the cartridges
5) All of the big chunks are trapped in the dc collection bags to the cartridges are safe
6) The cartridges are used as they were intended with the air flow from the outside to the inside
7) Dust may fall off or be taped/shaken off the outside of the cartridges and fall onto the floor of the box where it should stay

Disadvantages:
1) Big
2) Looks like a big ugly submarine
3) Pressure could build in the box
4) Lacks the gloat potential of a clearvue, etc J
5) A bit more work to empty the bag

Thoughts anyone? I am very interested in the thoughtful feedback that this group is capable of.

Richard

P.S. Anyone have a 2hp 30 micron DC in MA/RI/NH that they would like to sell cheap now that they have upgraded to a cyclone?

[Mike Cutler]

Richard.
Does American Felt and Fabric have a better bag for your DC? I'm fairly certain that I have seen 1 & 5 micron bags available for your DC.

Is this the correct replacement bag?

http://www.amazon.com/Delta-50-841-Micron-Replacement-50-840/dp/B0000223BG

[Ron Brese]

Looks to me like it would work. It really won't cost that much to try it.

Ron

[Alan Schaffter]

Two words-

Heat- it will likely cause your motor to overheat or at the very least cause premature bearing failure due to heat.

Dust- dust will get in your motor. Even if your motor is a TFEC, you will likely clog the fan housing.

I wouldn't do it.

[Richard Kagen]

Why do you think it would be any hotter or dustier than running not enclosed?

[Ron Brese]

You know Alan is right. The heat from the motor will be more concentrated in the enclosure and will not be allowed to escape as readily.

Ron

[David Epperson]

As I read your description, the motor would be inside the box, WITH the 1 to 30 micron dust laden air. Of ever increasing concentrations of solids. IF the motor was outside the box and the filter bags inside - I can see that it would work as you intend, although you do lose some of the noise muffling that way. The TEFC (Totaly Enclosed Fan Cooled) motor bearings SHOULD be pretty much impervious to any damage by the dust passing through the motor fan, but in this situation the dust accumulation could become all enveloping, cutting off cooling airflow across the motor housing -thus increasing the motor temp. And this situation could even happen before the cartridge filters got "clogged", since it would be the dust dropped from those filters that would cause the problem, not the dust IN the filters.

[John Schreiber]

I like it. Mostly because it's cheap, practical and should be nearly as effective as the big buck solutions.

I don't think there will be much heat build up. After all, any time the motor is running, there will be plenty of airflow through the box. You would probably want to brush off the motor every once in a while when you are emptying the bag to keep a blanket of dust from building up on it.

I'm picturing truck type filters where the air comes from the outside of the cylinder of filter paper then passes out through the center. I guess you would start with one or two and add more if needed because the pressure buildup.

My ideas. Not worth much, but keep us informed how it progresses.

[glenn bradley]

Hi, as others have stated; I wouldn't think capturing the device in it's own environment would be good over time. I have an older AP400 with bags very different than those I see on them in stores now. They state 3 micron in the paperwork which is still letting the little beasties through. Maybe they were shooting for more airflow with the 30's ?

There are several after-market bags available. I have the luxury of working with the garag . . . er, shop rollup door open. I also wanted a seperator for the conveniences they provide. The impact of the seperator and changing to 1 micron bags would probably hit the airflow too much. The seperator alone puts quite a hit on my unit but I chose that and passed on the better filtering which is OK (yah, right) in my environment.

[Jamie Buxton]

I like the approach.

How do you know if the DC's bag is full? And how do you empty the bag. Are you committed to opening a door to check the bag, and to empty the bag? Instead of doing what's on your diagram, how 'bout the following...

For the lower bag, use an impermiable plastic bag. Many bag-type DCs do this. Change your box so that it encloses the upper bag (which is still the cloth filter bag), but not the blower or the lower bag. The result is that you get to check the lower bag just by glancing at it, and you get to empty it without fussing with doors and such. You also get to use the power switch mounted on the DC. Oh, you also get around other posters' concerns about enclosing the moter inside the box.

[Robert Mahon]

To your statement "Looks like a big ugly submarine", I take umbrage.

Being a former Submariner, I find nothing ugly about them. In fact, I have pics of them all over my shop (which is a lot safer than those from Playboy or Hustler).


On a more serious note; if using an impervious plastic bag for the lower bag, DON'T use a big plastic trash bag :eek: .


As Clint Eastwood once said, "I know about things like that" (AND, LOML reminds me about it from time to time).

[Frederick Rowe]

Richard- It seems like you are in the same quandry as most of us working in basement/home woodshops. I think many wood workers become frustrated at the high cost of cyclone DC systems which will require 220v, 8' ceilings, and hard tubing to tools. The reality of which is, you can spend $1,000 for a cyclone, but it won't improve your overall air quality unless you have the equivilent DC at the tool. An example; no DC will collect the saw dust generated by a typical table saw from the typical dust collection port located at the base of the cabinet. If your tools are stationary, and you have upgraded the collection at the machine, then the cyclone system is a good choice.

But you are ready to improvise, and it sounds like you are on a budget, so, rather than try to achieve DC down to .1 micron at the machine, think in terms of your mobile DC to the tool being used (for your existing DC I'd recommend an aftermarket pleated filter such as Wynn Environmental) and build a ceiling hung air cleaner. They are not complex, can be home built with salvaged HVAC motors and blowers, and you can fit them with a broad variety of HVAC style filters. You can use a combination of bag with electrostatic prefilter, or any number of other inexpensive, easily found filters. Properly sized, the air cleaner will change the air in a closed room several times an hour and filter the most of the dangerous small wood dust likely generated in your shop. Put a cheap timer on it and let it continue to clean after you've answered the dinner bell.

I believe a lot of woodworkers fall into a cycle of, after cleaning up a dust covered shop for the hundredth time (or worse-cover your wife's stored Christmas decorations in dust), swearing to bite the bullet and buy the cyclone and commit to the tubing. Then the bills come in, we see that 8" jointer on sale, or just can't pull the trigger when you add up the cyclone, tubing, shipping, etc. . . I've found a balance with a 2HP DC w/cartridge filter connected to a "two stage trash can separater" and a ceiling hung air filter. I wear a cartridge style dust mask during sanding, MDF, or other messy operations. And about once a month, I switch on the ceiling air cleaner, put on my mask, close the doors, and hit the shop with an electric leaf blower, then walk out.

It isn't perfect, but on average my shop is relatively dust free, and I don't think many us would be happy working under a fuming hood. Good luck with whatever you decide. Post pictures and let us know how you did.