Interesting idea - passive particulate filter

[brokencookie]

One of the engineers where I work is planning a pompei oven build. ( I am not just a builder, I'm a pusher ). He has come up with an interesting idea to create a passive particulate filter that would also cool the oven exhaust some. In a nut shell he wants to us a water spray over a speader in the chimney. We do this in the refinery on a large scale but the industrial version requires fans and pumps etc.

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Here is a real rough drawing of the idea. Normal water pressure would lead to a spray nozzle 2/3 up the chimney ( this could also be a water trickle rather than a spray. The water would flow over a peaked set of flue tiles and sheet down to a catch basin also made with flue tile. The basin would drain to a pipe on the outside of the chimney. This should make very little difference in the draw and clean 99% of the particulate. Of course he is an engineer and my experience says that anything an engineer designs ends up working differently in the real world.
Has anyone seen or tried anything like this ?

Bruce

[brokencookie]

Re: Interesting idea - passive particulate filter

Sorry for that poor excuse of a diagram. I don't have and drawing tools handy so let me try to describe it a little better.

Think of water flowing over a tent ( hangin in the air). When the water reaches the bottom of the tent it sheets straight down to an angled catch basin. Kind of like stacking cups. There is sufficient space between the two cups to allow free vapor flow between the cups. Maybe like blowing smoke through a waterfall. I know the concept works, at least on an industrial scale, I am just not sure if a pizza oven produces enough draw to pull the vapors through the water curtain.

Bruce

[Faz]

Re: Interesting idea - passive particulate filter

I'd be concerned about a build up of salts/soot/particulate on the plates, because unless they are easy to extract and clean the build up will eventually impede gas flow and cause smoke to come out of the door.

I also know from experience that it is essential in industrial applications to make sure the water distribution is very evenly distributed around the circumference of the plates, otherwise you will not achieve very good abatement.

Sorry to sound like a bad news bear!

Would the cooler exhaust temperature also reduce draw?

[brokencookie]

Re: Interesting idea - passive particulate filter

Would the cooler exhaust temperature also reduce draw?

He is taking about a 2 to 4 inch gap between the plates which should not reduce the draw ( in theory). I think he is assuming that the drains will draw down the particulate and he would have catch basins with "nasty" water that he would use to amend the acid soil in the area.
Personally, I think this is more trouble than it is worth. My observation of George's oven was that the burning is so complete that very little exits the oven but gases.
Engineers are a breed unto themselves. Everytime one of them gets an idea at work we smack him on the head until we pound some everyday common sense into him. I think I'll use a firebrick for effect.

Thanks for the input

Bruce

[dmun]

Re: Interesting idea - passive particulate filter

I think this is an interesting idea, and that your friend should be encouraged to develop it for use in smoke control areas, like those in the UK and California.

It might even be a commercial success, for things like fireplaces in ski areas.

It's true that a hot running oven doesn't produce visible smoke, but that's not true when it's starting up.

[PizzaPolice]

Re: Interesting idea - passive particulate filter

Wow! This is so crazy that I had to weigh in. I must first post this question on behalf of the regular folks here. WHY?
Ok. Now that that is out of the way, let's dream. Chances are you do not have some humongous 180 foot stack fitted with powerful blowers that is ripe for installation of scrubbers and precipitators. I'm guessing you have a normal 4-6 foot chimney like the rest of us. If I were on one of those cable shows where tree huggers attempt to save the environment, I would do this. Leave the natural flow alone and augment it with a commercial chimney blower. The flue gases would be directed into a chamber situated away from the chimney. There, you could conduct all manner of wizardry, witchie-poo and wetness without losing the integrity of your WFO. So there. I said it.

[asudavew]

Re: Interesting idea - passive particulate filter

Wow! This is so crazy that I had to weigh in. I must first post this question on behalf of the regular folks here. WHY?
Ok. Now that that is out of the way, let's dream. Chances are you do not have some humongous 180 foot stack fitted with powerful blowers that is ripe for installation of scrubbers and precipitators. I guessing you have a normal 4-6 foot chimney like the rest of us. If I were on one of those cable shows where tree huggers attempt to save the environment, I would do this. Leave the natural flow alone and augment it with a commercial chimney blower. The flue gases would be directed into a chamber situated away from the chimney. There, you could conduct all manner of wizardry, witchie-poo and wetness without losing the integrity of your WFO. So there. I said it.

Why yes you did!

So basically, we are talking about a water filter(bong) for our ovens?



Never thought of filling it with cannabis.... A treat for the neighbors??
Followed by pizza!
Cuz I am sure my neighbors would all be hungry after a couple hours!

[Barberque boy]

Re: Interesting idea - passive particulate filter

Now that was an enjoyable thread. Always trying to build a better mouse trap.

[asudavew]

Re: Interesting idea - passive particulate filter

Now that was an enjoyable thread. Always trying to build a better mouse trap.

I think we all go through it...

I know I did!

[Inishta]

Re: Interesting idea - passive particulate filter

So basically, we are talking about a water filter(bong) for our ovens?

Perhaps something like this Dave.........not that we know what you're talking about.........

[brokencookie]

Re: Interesting idea - passive particulate filter

So basically, we are talking about a water filter(bong) for our ovens?

HA HA HA HAAAAAaaaaaa!! ( I think I hurt myself ) Exactly, right. A water bong for the oven. I think he is concerned about the occasional burn bans in our area. Yes, the pacific northwest is known for rabid tree huggers. We have this exciting dialog about endangered wild life all the time. Some of the endangered critters like to eat the other endangered critters and causes no end of anguish Personally, I am a conservationist. Lets be responsible stewarts but not forget how tasty animals are .

With our canabis loving friends from Vancover we could develop a chimney pot bong. You could add "herbs" to your pizza and enjoy the smoke while cooking. Add a few colored lights for entertainment and a Pizza Party would have a whole new meaning.

Bruce

[shack]

Re: Interesting idea - passive particulate filter

Actually these soot cleaners are commercially available and are required for most new wood oven installs in the EU. I'm going to need to use one for my next restaurant here in U.S. due to the location.

Several manufacturers, but Valoriani is one - they are rep'ed by Mugnaini here in the U.S.

:: REFRATTARI VALORIANI DAL 1890 ::

Shack

[vintagemx0]

Re: Interesting idea - passive particulate filter

It's a very similar problem to the one that fireplace manufacturers face with regard to emission control. Presently, there just isn't any practical technology in existence that performs very well because of the conditions that exist within a fireplace. They scarf-up large quantities of excess air that dilute the concentrations of the flue gasses and cool them down, taking away kinetic energy and reducing their volumetric concentrations that inhibit the ability of any chemical or catalytic treatments to occur.

I must say generally that I think WFOs are inherently "cleaner" due to the intense fire chamber temperatures which really help promote complete combustion of the organic compounds within the smoke. The largest discharge of "particulate" from a hot running oven is elemental carbon (soot). So, a percipitator could be likened to a bong in terms of it's ability to trap "particulates".

Our regulators and the EPA are concerned more about particulates that pose the greatest health concern, which are volatile-organic compunds (hydro-carbons) in the 5-10 micron size. There are literally hundreds of species randomly forming in wood smoke such as formaldehyde, acetone, methane, and various acids to name but only a handful. These little bastards find their way deep-deep into the deepest corpusals of your lungs and stew, and so the environmental concern. These little VOCs remain in gasseous form at relatively low temperatures too, so they could easily pass through a percipitator in abundance...like THC gets through a bong... (so I hear...)

Ken