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I Forge Iron

chimmney set ups.

Dave M

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Ok so here I go picking every ones brains again. I have pretty much finished building my new shop and now it is time to give my forges a permanent home. I have both propane and coal forges + welders, torches and a plasma cutter. Here is my plan let me know if this will work or if it is aready working for you. So for the coal forge I am thinking standard stove pipe (8" or 10" ) coming off the top of the side draft hood, run up the out side wall to the right height to give me proper draft. Now for the propane forge and welders I am thinking a sheet metal hood with with fan ducted outside but I am not sure if I need to run a chimney all of the way up the out side. I think I have to because the shop has a full second floor. Now here is were it gets ugly I need to heat my shop, if money was free I would use a direct vent propane heater but it looks like I will be using a wood stove for now. So it seems I would have 3 chimneys run up the out side of one wall, using the other walls is not an option. I also have to check the building code but I don't think that chimenys can be shared and in the winter there is a chance I would be using all 3 at the same time. Please tell me I am over thinking this.:confused: Maybe 1 chimeny for wood stove and use a hood that I could roll the other stuff under and or hook up to with its own chimeny. That would give me only 2 chimenys:).

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over thinking this

over thinking this would be hooking all three to a wet scrubber to both get rid of all particulate matter and transfer a large portion of the heat to water (then dropping a heat exchanger in to transfer that to clean water and using it for space heating or hot showers :P

as far as code....permit? I was just trying to do the right thing
odds are the energy invested in forcing the air would be repaid in the heat scavenged ;)

Venturi scrubber
basic sheetmetal work and some plumbing


Cyclonic separation


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Ice Czar,

Thanks for bringing up the technology of Scrubbers and Cyclonic
air cleaning systems!

Please remember for these systems to work effectively, they must fairly highly engineered. The air flow veleocitys must be very high and pressures high. The air velocity and pressures are typically 10- 30 times higher than what is present in a home heating system.

Power consumption will be high due to the high velocities and presssures of the systems.

I would save these systems for applications where government and neighbor relations require such an application. Remember that if these are required by the goverment detailed designs and stack tests may be required at a great cost, more than cost of a fine German automobile.

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when you have to scale them up to industrial size Id agree, and going at it blind and on faith isnt recommended. However we don't have to. This isnt any more difficult than a home woodworking shop dust collection and treatment system.

Bill's Cyclone Dust Collection Research - Doc's Orders
Bill's Cyclone Dust Collection Research - Projects

In fact its easier because with a little forethought an energy scavenging wetscrubber can be far more close coupled than a distributed set of shop tools. We are working with a temperature differential that is assisting draft, and as a group we are for more likely to have the tools and experience to make this stuff than the average woodworker or general public.

You can also benefit from careful proportional observation when looking at a given component. If after the researching there is still engineering doubt you can run the numbers. Its fairly obvious at this date that any official oversight from government will proscribe any activity you might contemplate, but they have to catch you first. Check your ordinances and odds are if your in any suburban or urban area your rights to employ a solid fuel are already proscribed. Better to address the root cause of any complaints with plausible deniability of the required certifications, then to be reported and forced to pony up the cost of a luxury car. ;)

Finally as far as energy costs, your already investing in the fuel, if adding a few blowers and pumps enables you to scavenge it for home heating or something more ambitious its offsetting energy your already paying for.

these may give folks some ideas ;)
Combined cycle
5916140 (pdf)
5899067 (pdf)
Hydraulic accumulator

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I have done a fair amount of forging in a shop that had one chimney, a coal forge and a woodstove. The forge had a very large hood over it, and the woodstove had a short stack that just directed the smoke under the forge hood and into the forge hood stack. The forge had a draw pipe hanging down. We never had many smoke issues in the shop, it seemed to work very well. The forge stack was probably oversized though, and I think there was a fan in the stack somewhere that was sometimes turned on.

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I Do Not Want To Go Into The Thoretical Discusion And The Proffetional Ingeneering Of Chimnies. What I Say Here Is Based On Waht I Do And Did At My Smithy And School And It Works Fantastic And Very Symple And Cheap On The Long Run.
1 The Chimny Is 12'' Made Of Stainless Steel Not More Then 0.4 Mm Which Is Aprox 1/64'' The Hight Is 10' And One Can See In The Foto That The Chimny Is Out Of The Building Seating On A Squer Tonnel 13''x13'' That From The Center Of The Fire To The Center Of The Chimny Is 4' One Can See Allso The Cover Without Hinges To Clean The Ash Every 6 Years.
The Squer Tonnel Is 4 Degrees Down And Not Up ,if U See There Is No Hood To The Chimny Because The Hood Is Disturbing The Colume Of Air To Run Up Freely So The 4 Degrees Down Helps The Rain When It Is Raining To Stay Out Side And Not To Stream Into The Forge.
The Tunel Inside The Smithy Or The School In That Photo Is Cut In 35 Degrees So The Upper Side Is Over The Center Of The Fire And Instantly When We Put The Fire The Suction Is Working Very Good .there Is No Hood To Disrurb And No Need For The Hood.
At First When One Thinks That Stailess Steel Is Expenssive On The Long Run No .because Of The Sulfor In The Coal Fire The Regular Chimnies Are Rustting Very Fast And In Many Places Within Two Years U Must Change The Pipes.
The Stainless Chimnies At My Smithy And School Are In Use From 1992 Its
Now 16 Yeas And They Are Like New!!!
2 In Germany It Is A Mast Bylow To Have Possitieve Suction That Is Done In Maney Verssions You Are Not Alowed To Build A Smithy Without Possitieve Suction. To Reason Is That Many Days In The Year The Temp Is To35-45 Degrees And Then The Chimny Is Working Backwords Into The Smithy.
Ingeneering Is Very Good But They Also Make Mistakes.at The School In Berlin That Is In An Urban Area They Where Porced To Put A New Vetilation System With Speciel Filters To Colect All The Dust Ash And Other Chemical Impurities That Went To The Air And Disturbed The Population Around.
And It Cost A Lot A Lot Of Mony. The Moment They Put It On The Hole System Explodes And Went On Fire Luckyly People Wre Only Injured.
3 In Many Places In Europe They Put A Copper Pipe Spirle In The Chimny To Heat The Water That Are Running Into The House Into A Heat Themoss Collector And The Have Hot Water All The Time
Hope It Helps A Bit
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Thank You, Thank You, Hofi.
You have solved a problem for me!
Thank you for thinking out of the box of my “so called” standard practices.
I have decided that I am going to construct a similar configuration just as you have shown us. Although, I plan on adding steel wheels into the equation. Now just try to figure that one out! Ha, Ha.
Thank you for your very valuable time, expertise, and wisdom that you share with us.
I have always found your ideas and concepts to be of great value.
Be safe!
Old Rusty Ted

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I have just one question Hofi
1. what kind of coal is typical at your school? (sulfur content)

as a side note my posts here and elsewhere regarding more complex solutions are a necessity where Im at. If I sprouted a stainless steel chimney off the backside of my house Id have the local law breathing down my neck a few hours later. ;)

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very low :P

no law against stainless steel, just against burning solid fuels plus some noisy neighbors

there are very tight ordinances regarding air pollution all along the Rocky Mountain Front Range, like Los Angeles which is between the sea and the mountains
Denver hashad a very bad smog problem, jet stream comes over the mountains and trapsbacks the air against the mountains quite often.

Because of weather patterns, the city is prone to temperature inversions that trap warm air under heavy cool air, keeping pollution stagnant over the city.

Region 8 News Release - EPA proposes change to Denver area's air quality status for airborne particles

my plan is to treat and duct the exhaust to a greenhouse for further treatment
Living wall Biowall | Live Building Living machines Aquaponics

the CO2 will be good for the plants and they will filter out any remaining NOX & VOCs
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Boy I sure don't want to get into a big engineering discussion on various scrubber and cyclone related cleaning systems.

I am an Liscensed Professional Engineer and have designed and installed numerous scrubber and air cleaning systems.

I WILL NOT install one these systems in my shop. Nor even think of the engineering required to do so.

If air pollution is a concern based on your neighborhood, burn coke, propane or natural gas. Oil would work to if you can carefully control the fire so it does not smoke.

The EPA has this principal, if you install an air pollution control device you must report it to them, get a construction permit and then verify its proper operation even if it is not required.

You do not want to go down this road!

If you install a wet scrubber what do you do with the dirty water. It will take a permit to dispose of it legally. Again you do not want to go their.

Hofi is correct. Make it and keep it simple!

Simple is beautiful. Any Engineer can make it complex!

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actually thats exactly where I plan to go :P

aside from art my abiding interest is in permaculture and ecological engineering
this is a home shop, but the design objective is to research synergistic technologies, the water is treated with Phytoremediation, the sludge is incorporated into ceramics geopolymers glass. The objective is to scavenge energy from one process to the next, and employ the waste stream of one process as a key component of the next. I call it the Sampo Puzzle. (Project was taken :P )

I do have a few odds and ends I need to find a use for ;)
(acquired in an ill conceived scheme to review computer thermodynamic solutions and power supplies, which unraveled on me)
I talked my way into a blacksmithing shop specifically so I could develop the skills and tools to do this project ;)

I think ecological engineering is an emerging art form
New Alchemy Institute

environments that renew themselves, clean themselves, and are married to how we employ energy for work
while my background isnt in engineering Im no slouch at science, but I came at this from the arts
used to work for these guys Communication Arts, Inc.

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My Daughter Lives And Teaches ''permacultuer'' And My Granddaughter Too
The Toilets Are Without Runing Water And On The Very Small Plot Of Land Vegetable Are Being Growen All The Year Around Allthe Garden And House Remaines Are Put In ''compost'' That Is Been Put Back To Fertile The Gardening
We Do Not Use Soap Or Chmicals To Wosh There Are Netueurals Matirials To Do It Better Then Soap.the U Can Reuse The Water For Irigation.
Again It Is Very Very Simple And Right Way Of Life And It Is Healthy Very Healthy Too.
Ice You Are Bombing Us With Those Long Very Long Articelson How To Live With Natuer And Not Against The Natuer ,please No Offence !only From Looking At Those Articales I Get Headache ,we Call It Here In Our Society
'' Rain Of Words On Desert Of Ideas''
''permaculter'' Is A Way Of Life A State Of Mined And Very Very Simple And For God Sake It Is Not A Religion !!!!!!!!!!!!!!!!!

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Ice You Are Bombing Us With Those Long Very Long Articelson How To Live With Natuer And Not Against The Natuer ,please No Offence !only From Looking At Those Articales I Get Headache ,we Call It Here In Our Society
'' Rain Of Words On Desert Of Ideas''

What a wonderfully poetic way of phrasing it - much better than "Information Overload"!
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Ice You Are Bombing Us With Those Long Very Long Articelson How To Live With Natuer And Not Against The Natuer

maybe you should look again, because that isn't a fair assessment of what I linked.
Permaculture can be relatively simple, but ecological engineering is a highly complex interaction of biological processes with a specific waste stream to address

those are world renowned biologists and pioneers in ecological engineering

just one example
Noorder Dierenpark Zoo - Emmen, Netherlands
host to 1,500,000 visitors annually. A Living Machine system at the zoo treats 220,000 gallons per day of wastewater generated by visitors and the maintenance of the housed animals. Treated wastewater is reused on-site for toilet flushing and other non-potable uses, including animal basins. As a result of the water reuse an 84% reduction in water consumption at the zoo has been realized.

anyone that has difficulties with information density is of course welcome to skip the links :P

this is science not religion, and such systems can be designed to treat specific waste streams, including industrial pollutants like hydrocarbons, cadmium, chromium, nickel, lead, ect.
which of course leads us right back to being "thread" relevant ;)

ps methane is another typical by product of such living machines (from the anaerobic reactor)
and that can be put to a more direct use
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wait...I thought this was about forge flues, not ecology


A typical, modern glass studio consumes 2- 6 million BTU of gas per day, for which prices have tripled since 2001, resulting in numerous closures of glass studios worldwide. Thousands of years of heritage and tradition are being extinguished. Costs of operating a glass studio combined with the loss of waste heat from the furnace make this an opportunity to collaborate efforts, to save fossil fuels, and provide community-based heating.

blacksmiths are different how? you can look at one little part of a problem or you can look at a bigger picture of a process, and entertain alternative solutions that may have something new to offer.

Chimneys are pretty well covered ground for the last several centuries, steel, refractory, stone, ceramics
most of the energy goes straight up and is gone. Simple certainly works, its easy to implement, its rarely the optimal solution, and in this case isnt horribly energy efficient, if it was possible to run a power hammer off the fuel your already burning, is it worth investigating? discussing?

recuperator pdf
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Wow:). Thanks for all of the help. Do to our fire codes I will have to have 2 chimneys, 1 for wood stove & 1 for coal forge :mad: oh well. For the propane forge, welder and plasma cutter I will use a direct vent fan inducted hood. Hofi's system looks so straight forward that I will use that design. Don't know if I can come up with the extra money for the stainless but I am going to price it out because it would be a one time purchase. As always you are all just a vast wealth of knowledge, and save me time and again from reinventing the wheel so to speak. THANKS

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