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Forum topic by b2rtch posted 07-24-2010 11:09 PM 1772 views 0 times favorited 34 replies Add to Favorites Watch
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b2rtch

4823 posts in 2515 days


07-24-2010 11:09 PM

Topic tags/keywords: question

What do think about this idea:

I was having a nap (I got up at 2:30AM) and dreaming when I got this idea: with dust collector or cyclone one of the issues is to filter the air at the exhaust as to not reject fine dust into the air we then breathe again.
Some use bags but we know that they do to filter fine dust they are no efficient and they get dirty very fast. Some use filters which are more efficient but expensive to buy and to replace and cumbersome.
My idea is why not exhaust the air in a water bath?
Old oil air filters gave me this idea, they were extremely effective and efficient.
It would be easy to take the exhaust duct and to plunge it in a recipient full of water, from time to time, as needed, the water would be dumped (with the dust) and replaced.
The air could be let to free flow (to bubble ) back in the room or be ducted back ( enclosed container) in the room or outside.
In addition if flown back in the room you get a free humidifier in case you need it!.
What do you think?
Some vacuum cleaners work on this principle.

-- Bert


34 replies so far

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Sailor

543 posts in 2731 days


#1 posted 07-24-2010 11:33 PM

That sounds like an interesting idea. I don’t have the knowledge enough to say whether I think it will work or not.

How large of a water bath are you talking about?
Will the weight/pressure of the water reduce the suction of the DC system?

-- Dothan, Alabama Check out my woodworking blog! http://woodworkingtrip.blogspot.com/ Also my Youtube Channel's Facebook page https://www.facebook.com/SailingAndSuch

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b2rtch

4823 posts in 2515 days


#2 posted 07-25-2010 12:01 AM

I am thinking about a used plastic 55 gal (or less) that I can get at work. Even a 32 gal plastic trash can would work.
I would install a drain at the bottom.
Certainly you would not want to put the duct at the bottom this would create too much back pressure but just under the surface, may be 2.00”.

-- Bert

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Richard

394 posts in 2588 days


#3 posted 07-25-2010 03:58 AM

I too thought about this, I was vacuuming my house and I thought dusty air always filters back in the same room and if the exhaust was sent through a reservoir of water the dust would be certainly be left behind as the air bubbles floated to the surface. Also in the summer, the return air would be slightly cooler depending on the temperature of the water. Your idea seems workable, but I am curious what problems would present themselves when used in actuality. I also wonder if the water would cause back pressure on the air exhaust as its trying to force itself into the water.

I say go for it and let us know the results.

-- Richard Boise, Idaho

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b2rtch

4823 posts in 2515 days


#4 posted 07-25-2010 12:20 PM

I am no where close to try my idea. My dust collector is not yet installed.
The exhaust air would have to be just under the surface or may even just above the surface ( 1/8”) to have the air just “caress” to surface of the water and to minimize the back pressure. A dust collector moves a lot of air , that would make a lot of very big bubbles. May be we would need like a diffuser to spray the exhaust air over a larger surface to reduce the size of each bubbles.
When read I would be ready to try to modify one of these 55 gal chemical plastic drum with an inlet and outlet fittings at the top. The inlet would get just in the water or just above it and the outlet would have like a upside down “U ” on the top to minimize the transfer of water in it.
The biggest problem i see is to keep the water level constant enough so that the penetration of the exhaust tube in relation with the level of the water is constant.
If this fluctuates too much then the back pressure on the system is going to fluctuate just the same.

-- Bert

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christopheralan

1120 posts in 3187 days


#5 posted 07-25-2010 04:06 PM

I had a vac just like you described. I can’t remember who made it but it worked well. It was a nightmare to keep it clean after each use. It did a good job though.

-- christopheralan

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b2rtch

4823 posts in 2515 days


#6 posted 07-25-2010 04:14 PM

It seems that a wet scrubber would generate a huge back pressure mostly because of the mist separator. I have worked with similar piece of equipment in the oil industry.

-- Bert

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patron

13538 posts in 2807 days


#7 posted 07-25-2010 04:22 PM

they have ‘lint’ filters at the box stores for clothes dryers ,
for when you can’t get the exhaust out side
they aren’t to big , but use water as you suggest ,
check them out sometime ,
they are in the washer/dryer accessories area .

-- david - only thru kindness can this world be whole . If we don't succeed we run the risk of failure. Dan Quayle

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DYNO360

151 posts in 2332 days


#8 posted 07-25-2010 06:04 PM

We had a waterfall arrangement in a paint booth. The air was pulled away from the painter, through the waterfall and out a vent. We were shooting a lot of paint with lead and we thought it would help. It sure did capture a lot of overspray. As mentioned, it was not fun to clean. Keep us posted on your results when you get a working prototype.

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Knothead62

2581 posts in 2427 days


#9 posted 07-25-2010 07:17 PM

Put a pair of pantyhose over the vent. Works and if you have one of the cheapy dollar stores around, very inexpensive. Soldiers in the Middle East back in the 90’S asked for them from the home front to keep dust out of their weapons.

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b2rtch

4823 posts in 2515 days


#10 posted 07-25-2010 07:40 PM

I do not believe that pantyhose will stop .5 micron or smaller particles.
This is what we try to achieve with creating back pressure.

-- Bert

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Sawkerf

1730 posts in 2535 days


#11 posted 07-26-2010 12:05 AM

Considering the volume of air going thru the filter (~500 – ~1200 cfm), you better have a large tank of water or you’ll be blowing water all over your shop. Also, trying to exhaust into a tank of water will create a lot of backpressure which will seriously reduce the system flow rate.

-- Adversity doesn't build character...................it reveals it.

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b2rtch

4823 posts in 2515 days


#12 posted 07-26-2010 12:42 AM

Sawkerf, I am afraid you are right but the idea is tempting

-- Bert

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Sawkerf

1730 posts in 2535 days


#13 posted 07-26-2010 01:10 AM

Just for giggles, blast your compressor (~ 7 cfm @~90 psi) into a bucket of water. Getting the picture? – lol

-- Adversity doesn't build character...................it reveals it.

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BertFlores58

1684 posts in 2388 days


#14 posted 07-26-2010 04:42 AM

Scrubbers are different from what you are thinking.. which is called a DECK SEAL when you are onboard a tanker vessel. They have different purpose…

Scrubbers- they wash down solluble chemicals in the air… for example they take sulfur dioxide or other sulfides by spraying seawater to the air… in other words… H2O absorves sulfides … making H2SO4 which is acid… this is the reason why you have stainless steel to avoid corrosion inside.

Seals – this is similar to the function of the U-tube in the wash basin to prevent foul smell of the gases going out. It does not filter.. The medical application where the nebulizer uses have different purpose. Some medicine reacts on the water or some solutions… It acts as catalyst… some of them speeds up vaporization.

Bert (my namesake).. It is a good idea to filter out the air by using a seal…. But what are you filtering.. solids which can be done by sieves of different sizes.. Sediments like cyclone method is good enough. The pressure is the problem …. this can be solve by regulating the pressure both in and out of the seal. We are only after flow in the system… therefore you need to control the outlet (fresh air) to be a little less than the inlet (the dusty air). The flow should be given importance…not the pressure.
NEXT PROBLEM… You need to maintain the water and provide both bottom and surface draining. You dont need a running water… but you have to take out the floating objects and the heavier sludge frequently.

Hope you think of this info based on my experience onboard tanker vessels …. in terms of inerting using smoke from the exhaust system….

-- Bert

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b2rtch

4823 posts in 2515 days


#15 posted 07-26-2010 12:02 PM

BertFlores58 , thank you for your very good explanations.
the other Bert

-- Bert

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