Water Filter for DC?

[Ken Harrod]

Sorry if this has been covered before. I did a search and did not come up with anything.

I have read a lot of the threads about the various Dust Collectors out there. A lot of info about how most of the filters do not filter small enough particles, or need time to get seasoned until they could filter small enough particles.

Has anyone experimented with something like a big water bong? I don't have any experiences with them, but I saw them many times in college for other purposes.

It seems to me, having the discarge from the blower going through a pipe that has some amount of water above it, say 12" of water, then that water could capture any remaining dust that the Cyclone did not remove.

The remaning filter then should be a tall column, so that the water getting splashed around, would no get blown out into the shop. Possibly even putting some angled pieces that force the air to shift from left to right a couple times to act as a moisture separator like a boiler would have.

The main downside I see, is the static head presented by the 12" of water the air would need to blow through. I don't know what type of back pressure is normal with "seasoned" filters and how that would compare to a column of water.

Ken

[Karl Brogger]

Some auto body shops use a setup like you described. Honestly, I think it would be overkill for wood dust. You would have to build the dust collector almost from scratch. I'd be willing to bet you would have to double the CFM needed to get it to pull through the water as well.

How about moving the dust collector outside? It would have to be out of the elements. In the winter you would also want to be piping the air that is getting pumped out, back inside or else you'll be heating the outdoors.

or, another thought. Build an enclosure around the dust collector in the shop. Use a large number of furnace filters to filter the air after it has run through the dust collector.

I don't think you have a bad idea, just a complicated one that might require some trial and error. Which the errors get expensive.

[Phil Thien]

There would be too much pressure required for a DC to push air through such a column of water.

I had thought about a water-lined filter where the air would be swept across a wet surface. But the problem is that it would probably add significant amounts of humidity to a shop if let run any amount of time.

[Jim O'Dell]

Think about the Rainbow vacuum cleaner. That is how it filters the dirt out. But getting something to move the amount of air needed for a dust collection system would have to be huge. It's a great idea, but unfortunately, I don't think it is practical for the hobby use either. Jim.

[Bob Opsitos]

This is so strange, I had this exact conversation at work the other day. Reportedly there are industrial uses of this exact same type of dust filter, Torit was mentioned as one possible source. Haven't searched the internet to see who offers what. I'm willing to be that something could be adapted, most of the WW designs have dribbled down from industrial uses. Problem is that you will have to do the engineering from scratch. The other things we were discussing was what about disposal of the water? How would it be classified by the EPA, especially should you cut any pressure treated.

Bob

[Ken Harrod]

I have seen water filter systems in use at a Chrysler plant. They used them in the paint booths. The paint booths were "down draft" spray booths. The floor was an open grid type of floor that had many sprinklers underneath, creating a continuous spray of water under the floor. I don't know what they did with the water once the paint products were captured in the water, though.

For a hobbyist workshop, I would not think the EPA would be concerened with the water. If it was a system for a large commercial outfit, then it might be different. I don't see dirty water getting released to the environment being any different than us venting outside with our DC systems.

I figured it would be a build from scratch type of thing. I had been looking at Bill P's pages and saw he took into account about everything you could think of to come up with the correct design, blade size, motor, etc... I was thinking maybe if the backpressure from the 1 foot of water (or what ever height would be needed) was taken into account, then maybe a slightly taller (or shorter) cyclone, or wider impeller... would then result with the proper air flow for the whole system.

The humidity thing might be the big problem. I am not sure if blowing air through water changes the humidity in the space or not. If it did, that would be a bennefit in the winter when the heater is making the air so dry. Not so good for the summer, though.

As far as the waste water concern, I was thinking the water would just be drained to a nearby sink, or possibly just dumped out doors. If you let the water sit outside and all dry up, you might end up with all the dust in a nice solid disk. Might be an easy way to make big MDF circles. :)

The cartridge type filters are pretty expensive. Building a muffler gets additional expense. The water column might cover the functions of both components, with one cheap simple item.

You know how soothing the sound of running water is outdoors. People spend thousands of dollars building a pond or fountain in their back yards for the soothing sound of water. Well, imagine how soothing the sounds of woodworking will now be with the big bubbling water column. :D