Outdoor Wood Furnace Info
Outdoor Furnaces - Manufacturers with NON EPA-Certified Models Only => Home Made => Topic started by: shane g on October 22, 2011, 05:50:42 AM
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Hi guys
i am new to the site i have read alot before i joined and i finaly made the decision to build my own owb
if any of you guys could help it would be appreciated
heres the deal i have a 1200 square foot home i want to build a owb that will heat my home and a 30x30 garage i plan to build eventualy i work at a factory that i get sheet steel at a deal
i have already aquired 6 sheets of 5'x5' 1/4' that i was going to use for a water jacket
i am wondering what type of firebox i should build i was looking at building a (ripple top)type like i think cb uses or a round like a shaver i am looking at what would be the most eficient and what would produce the least amount of smoke so my questions are
what firebox is the best?
how should i position the flu in the firebox?
should i use a blower or a natural draft?
any suggestions will be a big help i basicaly know how they work but dont have any specifics
i will be the first one around here to build a stove and i want it to be as eficient as possible
i would like to build a stove like jackell440 but thats a little complex for my first stove
thanks in advance for any help
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Welcome to site!
Lots of great guys here to help.I am more than glad to help you if I can.
Unless you have access to a press brake to form the ripple bends in the top I would for gore that plan.Too many seams to weld for each ripple.
Now I would build a fire box with flat sides and octagon shaped to some point. heat transfer happens faster on a flat surface than a round surface.
I would then go and study different design stove exhaust passage designs.I am a big fan of how the Portage and Mains are designed.
they have access to clean the exhaust and are double pass to extract heat in the water jacket.
I would definetly go with an blower.I like to the fire to pick up fast and start producing heat,rather than lazily stoking back up.
I would use your 1/4" for your fire box.Then get some 1/8" or 3/16" for your water jacket.I used 10 guage.Heck water tanks and oil tanks aren't that thick.
You could build a stove like mine.You would actually be way ahead if you did build a gassifier.They use less wood and smoke alot less.
Don't put that option out yet,You will find that after you build this once you wont be in a big hurry to do it again.
Make lots of drawings and try to keep track of the big picture of how everything works together.Always be planning 5 steps ahead.
take your time ,and think out every step of your build.
good luck,and oh yeah take lots of pics! :photo: :thumbup:
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Jackel440,
thanks for the warm welcome. I actually have acces to a huge press brake a nice deltaweld miller mig
plasma metal cutting laser ect. i am a maintenance mechanic for a truck manufactoring plant here in VA. and i have gotten permision from my boss to build it in the shop on my off time (what little i get ) if you think a octogon style box is better i may go that route it still would be less welding i cant find a design on the web about the port and main flu design they did say on their site smoke goes below through a slot in the firebox I still can't comprehend smoke going below the fire seems to me like it would choke out but then again i am still in the learning stages of the designs
let me air out my thoughts on a flu design a 3x3 firebox ripple or octogon flu positioned 2/3 of the way down in the back of the box coming out the top then 90 then out through the the back of the water jacket with a tee on the out side of the stove for clean out and if i build the octogon shape put a deflector in front of the flu in the firebox to trap the smoke also the blower comes in from the back and blows underthe grate to excite the fire from underneath instead of a blower on the door
this is just my thoughts i am open to ideas
also should the flu itself have any kind of baffle or dampner in it
any way i am holding anymore questions on the other things dont want to overload anybodys brain
i have a ton of questions
jackel440 thanks for help i envy your stove that thing is killer iwill be calling on you often sounds like you have done some trial and error
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Welcome to the site shane, there are plenty of guys here with some great ideas. Remember take plenty of pictures and keep us informed of your build.
Bill
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Shane,
Good luck with your build. I am in the process of building mine now. I was planning on following the Central Boiler style with ripple also, But found it much easier to put the heat transfer tubes through the top of the firebox. Actually we don't have a whole lot of man hours involved in building it so far. The outside dimensions of mine are 48 x 48 x 48. firebox is 30 x 30 x 42. Will hold almost 300 gallons of water.
Newmod
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Welcome Shane, I think Portage & Mane Flue goes from back out of fire box to front then back to back and out top of stove. Any way here is a link showing flue.
Good luck on your build!!!!
http://www.portageandmainboilers.com/pdf_brochures/ShakergrateWebColor%20apr7.pdf (http://www.portageandmainboilers.com/pdf_brochures/ShakergrateWebColor%20apr7.pdf)
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anything you build you will be happy with. if you build the traditional style furnace , i would recommend octogon or round,mainly for the strength,square has creasote issues worst.i have a round style and it has very little acumulation of creasote.the flu down low in the firebox is good ,smoke has to pass by hot coals helping it gasify . if you decide to build a gassifier style ,you need to ask yourself if the extra labor and materials are going to pay off? it might be the diiference of a cord or two in savings,if you buy cord wood in log lenght thats about 150 bucks more ..around here anyway ,not really much. gassers are supposed to be less smoke but once you get the hang of it you can get the old style to do very well. last , i never hear guys say anything about using stainless steel for the water jacket? this is undoubtably the biggest problem with owb ,how many posts and pics have you seen on here with rott holes in water tank. the cost of 304 grade i know is alot but look how much your saving...i think its a good investment. ......just my 2 cents.
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wow first i want to thank everybody on here i never dreamed there would be a forumthat would be as helping as this one i have learned more to day then i have in a month there is not alot of stoves around here the ones that are here are mostly taylors people bought like 10 years ago so from what i have seen i am going to be the first to build my own
the octogon shape is starting to grow on me and if putting the flu pipe down in the fire box would help and then out the top of the firebox then 90 out the back of the water jacket
wood here is not that big of an issue i am on a 500 acre hunting lease and i can cut as much dead and down wood i want and if i run out there i can pay 13.50 for a forrestry permit and cut up to 10 cords a year i just want a eficient stove that is not going to tick off everybody around me with the smoke
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by the way welcome! there are some really good people with good info here,if you take bits and pieces and combine them youll do something cool. sounds like you got the basics figured out. 2 things that help with the effiecentcy ,getting the gasses to ignite prior to leaving firebox,and capturing the heat in the exhaust. if you go to garn wood furnaces and check out the ''little magic refractory piece ''they use in the exhaust . that is where it gets super heated to ignite unburned fuel..smoke. then it runs thru a good length of exhaust ,submerged in water before it exits out.if you can do these things youll be sure to get the results your looking for.
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okay guys been studying on gasification i think with all the input on here i am going to build the octogon firebox 34"wide x 34" high x 42" long here is my understanding of how it works on the the down draft gassifier
i build a box attached to the bottom of the firebox with slots in the bottom of firebox going in to the gasifier box thinking the gasifier would be 10"x10"
the slots in the fire box being1"wide x 4" long and put 4 of them in spaced roughly 4-6" apart come out the back of the gasifier with my flu and 90 up through the top of waterjacket that would give me 53" of flu pipe inside the water jacket
please everybody give me your honest opinion
thanks :thumbup:
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i would think that the chamber needs some type of refractary brick and extra oxygen to get it to gassafy. by your measurements those slots equall 16 sq '' not sure if its to small? youll need a fan that puts out a lot of cfm.
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Your only going to need to decide on a nozzle size.Meaning your hole through the floor and into a refractory chamber.You willl have to have refractory block in the secondary burn chamber due to the high heat and burn temps.You will need a passage to feed frsh air to the nozzle to feed the gas chamber burn.
You will also need to feed air to the burn chamber so as to pressurize it and to force the smoke down through your nozzle.
Now I have considered going to a single nozzle on my stove just to see if there is any performance difference.I currently have 2 slots in my floor.
My stove runs a 500cfm blower to feed air to both chambers.
Now you need to have the brick to hold the heat to help restart the gasification burn at each cycle.Plus protcet the steel from the high heat.Now you need to design a long enough passage to extract all the heat from the secondary burn to be used to reheat the water in the water jacket.
I have the 6 3" pipes flowing from the double passage refractory chamber up through my water tank.
Now you will also need to design a bypass in your fire box to allow the smoke to exit out the top of your firebox when you first start your stove or are loading it.If not you will have smoke rolling out the door at you ,and you wont be able to see anything.
Plus I have had flash backs from the wood gas igniting as soon as it comes out the door and fresh air mixes with flame from the fire box igniting it.Only for a second does it happen and not always.This only happens if the bypass is shut and I try to load it while it is running.even though I have flipped the load switch on to kill the fan.
Some more tidbits for you to think about. :thumbup:
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Wow i was way off i guess i need to do some more research although the more i look at jackel's pics on here the more i understand so going to keep studying lol
just got to get my mind wrapped around it thanks for the help guy's
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jackel, if you made some blueprints from your furnace you probably would be a millionaire about now! lol..online price $19.99 and he''ll throw in the knives!
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yeah and pay for overnight shipping so i could start tomorrow
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Nozzle size is best determined by velocity of the gases through the orifice. To slow and you get bridging and burn out. Too fast and you get blow out and extinguish the bed of coals.
The calculation for velocity through a nozzle is:
Air Velocity, V=Q(air flow in cfm) divided by A(area of opening
in square feet)
The ideal nozzle velocity for a gasifier using wood, based on calculations derived from Imbert dimensions, is About 8-15 feet per second.
*I need to review some notes and may change that value upon further calculations but it should stand as a good starting point*
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once again when i think i have enough info to build the gassaifier i get blown away with more thing to figure and calculate LOL .
which is typical i usualy get in over my head and work my butt off to get stuff like that done.
but i am not going to do that this time with the time line to get this thing done and how much the materials cost holy crap if i want to get a boiler in place i am going to have to build a simpler one
i took your guy's advice on the portage&maine boiler design and i think i canbuild one similar to the ML series except a octogon style boiler i can bend that at work and only have 2 seams to weld
hopefully it wont create too much smoke and tick off the neighbors
should i still by a 500 cfm blower or will a smaller one work better for this aplication
i am still going to build a quality stove so i am going to need alot of help from here so give me your thoughts
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How much water storage are you planning on having? You can calculate that by finding the volume of the water jacket minus the volume of the fire box in cubic inches then dividing by 231 as there are that many in one gallon of water. Also, what is the btu capacity of your current heating system? I only have a 75 cfm blower on mine and based on my water temp increase/time I am making about 150,000 btu per hour. Where my house only needs about 70,000 to keep the wife nice and warm under the coldest of Wisconsin weather. If you can get this info together we can work out a fan size based on a reasonable refueling schedule. Also, try to keep in mind that about %20 of the air should only hit the coal bed, there rest needs to feed the top of the fire. Look into high efficiency epa wood burners. It's a very simple concept once you see it. I use a pair of 2" diameter muffler pipes I bent to bring some of the air up to the top of the burn box for secondary air and have very minimal smoke a few minutes after in kicks up. I wish I built a gasser off the bat but was in the same position you are now and winter waits for nobody. The elm stove is another good source of ideas for clean burning. Once its up and running you'll find a few tricks to keep the smoke down also. And maybe end up like me building small gasifiers for fun just to tinker with till you are able to build a new owb that does what you learned and wished about the first :)
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have not done the calculations yet been a long time since math classl :D my waterjacket is going to be 5'x5' square design fire box is going to make the octogon firebox 32wide x42 long with the water baffle and do the heat exchanger on the top like the portage and maine 6"x4" tubes
so thats the design i have settled on i will get my water storage figured (may need help from my kids with the math ) i know thats sad and then i get numbers out to you experts and help me get the cfm of my blower hoping to get the steel bent by next week and get started and get some pics on here thanks for the continued support from everybody here
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if i have done my math right my water jacket will hold 750 gallons but i am not a hundred percent sure i done it righti its been fifteen years since i did this in school my water jacket is 60x60x60
my fire box is 34x42 with two heat exchanger pipes being 6x4 tube running the length of the water jacket 60" if any of you could double check my work i would appreciate it
thanks
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i fat fingered the capacity i figured around 450 not 750 hahaha :bash:
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if i have done my math right my water jacket will hold 750 gallons but i am not a hundred percent sure i done it righti its been fifteen years since i did this in school my water jacket is 60x60x60
my fire box is 34x42 with two heat exchanger pipes being 6x4 tube running the length of the water jacket 60" if any of you could double check my work i would appreciate it
thanks
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your water jacket of 60x69x60 inches would hold about 935 US gallons i think
i am unsure of your fire box size you say 34x42 (and i am guessing 60 incehs long?) if so this would take away about 370 US gallons
then you could add back on about 12 gallons for your tubes
i get rough figuring 577 US gallons?
you can do your own figuring 1 cubic foot is 1728 cubic inches and one cubic foot holds 7.48 US gallons
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fire box was 34x34 octogonx42 long and water jacket was 60x60x60 i dont know what i am doing wrong with my math
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It's the octogon shape that's throwing it off. If you could load a pic of a sketch with the dimensions of each face then I or someone else can run the numbers more accurately.
60^3=216,000 cubic inches
If its a true and perfect octogon, all 8 sides identical in length, then we can use the equation for surface area of an octogon:
A = s squared times 4.8284
Where s is the length of any one side, square it, then multiply by 4.8284 and you will have your surface area.
Multiply by 42" length and you have your volume.
Take 216,000 and subtract the volume of your octogon (Vo) and the volume of your heat exchangers [(6*4*60)2=2880] divide that result by 231 for your capacity in gallons.
216000-Vo-2880
__________________ = capacity in gallons
231
Hope this leads you in the right direction.
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Shane-
Don't be scared by numbers and figures that are coming at you. Just draw up a rough sketch and begin. I would imagine your firebox will start out as a 10' long sheet of metal that your supplier will bend in an octagon shape for you. 10x12=120. 120 divided by 3.1416= approximately 38.2" if it were round(just imagine 8-45* bends in it to get your octagon shape). 38.2"x38.2"x42"x.7854=48136 divided by 231= just over 208 gallons. 935-208=727 gallons. You'll lose another 9 gallons or so that your transfer tubes will displace for a grand total of around 718 gallons. Awesome! You are going boiler-size-king of this forum. jackel440 is king for now of the home-made OWB's, so you'll be dethroning him. Don't be afraid of a gasser either. Shoot for your nozzle area to displace 1.5-2.5 sq. in. jackel's 500 cfm fan is the same one I used on my gasser, but I put a 250(?) cfm draft inducer on my exhaust also.
Good luck, and once again, we all like pics.
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haha dont think i will dethrone him built a masterpeice i am going to hold off on the gassiafier and just build the boiler the boiler as efficient as i can maybe the next one is this too much water? making the stove smolder more than it should?
my boss is helping me with some drawings so i can give it to the operator at the plant to bend my firebox but he had an emergency this week and had to leavetown so hopefully next week i will be able to get the steel and get the drawing to the press operator (the op is going to bend it on his break for a fifth of captain morgan LOL) then maybe i can start to put some of it together then i need to figure out how to get the right mix of air underneath and exactly what cfm fan i need to buy and how to route the tubes
just thought of another question when the water is up to temp i am going to have a spring return damper motor close the damper from the blower does the firebox get all air coming to it shut off as in air tight because i see some with a manual damper adjustment on the door and some in the flu
what is the best to have as far as eficiency and low maintenance because i want to be able to load this thing up before work and not worry with it until i get home 12 hrs later or longer
thanks for all the help
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im a big fan of mass storage,my furnace holds 1200 gallons .i believe this makes it more efficient because the fire cycles are longer burning cleaner ,putting more heat out . the off cycles are farther apart so less on the smoky startups, i also believe the larger mass holds temps longer. i have seen the benifits of more water capacity.in early fall i can shut off blower and control when i want it to burn without losing all its temp like a stove with smaller capacity of water. im adding a second air source ..to add to my forced draft.ill let you know now it works out when im done.
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The more mass storage the better. If you can get big hot all out burns and burn non stop from start to finish with no idle time you will have wasted no energy on smoldering and a roaring hot for is far more efficient than a smoldering one.718 gallons is a very respectable amount of storage. During mild weather you could probably get away without any smoldering idle time. And even during cold weather if you time it right.
You don't need any air adjustment in the door with a blower fan this would be bad. You would be blowing hit air right out of it. And no flue damper is necessary either. A damper on te inlet of the fan is best, there are a few ideas in the electronics section of the forum I believe for some retrofits on the shaver that work very well. You want your fan to be your only source of air so you have complete control if your burn. Airtight Fire box is the best way to go with proper air metering and control for best possible burn when not a gasser.
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haha dont think i will dethrone him built a masterpeice i am going to hold off on the gassiafier and just build the boiler the boiler as efficient as i can maybe the next one is this too much water? making the stove smolder more than it should?
my boss is helping me with some drawings so i can give it to the operator at the plant to bend my firebox but he had an emergency this week and had to leavetown so hopefully next week i will be able to get the steel and get the drawing to the press operator (the op is going to bend it on his break for a fifth of captain morgan LOL) then maybe i can start to put some of it together then i need to figure out how to get the right mix of air underneath and exactly what cfm fan i need to buy and how to route the tubes
just thought of another question when the water is up to temp i am going to have a spring return damper motor close the damper from the blower does the firebox get all air coming to it shut off as in air tight because i see some with a manual damper adjustment on the door and some in the flu
what is the best to have as far as eficiency and low maintenance because i want to be able to load this thing up before work and not worry with it until i get home 12 hrs later or longer
thanks for all the help
Well I never tried to get on a throne.I just shared what I built to show others what was involved with the gasifier I built.I am just glad to see people taking my build and going out and doing something with it. :thumbup:
Heck alot of people seem to be impressed with my stove ,but I see too much that needs improved and things that I wish I had been able to do differently at the time.I'm just glad she performs as well as she does.
There wasn't very good documentation of furnace builds on the net so I wanted to share as much as I could.I am glad that there was this great site to document the build on. ;D
You definatly want to have the fan to pressurize the air box,and be your only source for induction air.Just like you mentioned with the damper to seal the burn chamber use an damper actuater like I did.Mine is a Belimo unit.works like a charm!Go to my thread and look at the video I made of how mine works.You could build on like mine very easily,or your own design.Don't put any sort of damper in your door.
Some were concerned with my design not allowing any air to keep my fire going with long periods of idle.That was not a problem.Even when the furnace sat for 2 days without power.I had a 6" coal bed that as soon as I fired it up she relighted with no problem.
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Even when the furnace sat for 2 days without power.I had a 6" coal bed that as soon as I fired it up she relighted with no problem.
That's what happens when you wrap everything in ten billion square feet of kaowool ;D
But it just goes to prove that insulating the burn chamber, at least the bottom half, helps with efficiency so much. Keep the heat where you need it for burning, then grab what you can after its all consumed. A hot bed makes for quick restart and less energy wasted getting the fire going again and piece of mind in those very cold deep winter nights when the furnace wants to keep running. You'll never choke it out if you can keep at least the coal bed hot enough.
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all right guys i have run into a problem getting my steel the we are having quality issues with our steel supplier so i am not going to buy any from them until they get that straight i can get my hands on the same stuff i am building my water jacket it is between 3/16 and 1/4 " 50 grade do you guys think this would be suitible if not i will just wait but if so i can aquire that and get started sooner
give me your opinions please
thanks
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Welcome Shane
There is so much info on this website it is almost mind boggling!! I will ad my two cents . If I where you I would not start a build without a firm plan or design. You really need to look at the design of different manufacturers and take the things that make sense and incoporate them into your design. Changes you make along the way can have a way of getting expensive. You can check out some of the features on manufactureres wesites but there is nothing like seeing a stove in operation, and talking to the owner.
If you check out Jackels built on this site, he combined a Natures Comfort gassifier with some features from portage and main and some of his own ideas to build a one of a kind gassifier. I have never seen Jackels stove personally, but I have seen P&M's Optimizer 250 gassifier and I own a Natures Comfort GT-220 and both are very impessive stoves. Good luck with whatever you decide to build and always remember if there are no pictures posted here it never happened!!!!
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That should be fine for your water jacket.
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i did not clarify myself woud this steel be ok to use in my firebox or is it too thin its between 3/16 and 1/4 50grade sorry for the incomplete post
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Shane,
I've never built one with less than 1/4" for the burn chamber. The 3/16" should be fine for the boiler vessel.
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7ga (3/16" thick) grade 50 will work fine in your burn box. Most grades of "boiler plate" is nothing more than A36 steel with a few alloys added to reduce thermal expansion rates. But from a structural standpoint is still only A36. Your grade 50, aka A50 7 ga sheet steel has superior mechanical properties. As the grade number denotes the tensile strength in psi times 1000. A few strength calculations based on the modulous of elasticity show us that 7Ga A50 has a higher strength value than 1/4" A36. So your steel will be plenty strong enough, and also the alloys added for extra tensile strength also happen to reduce thermal expansion. The only loss you will have is a very slight chance that it might rust through a couple years earlier, but with proper maintenance this should never be a problem. Keep in mind also that the high end wood gas boilers like the orlan and the froling use material with less than 3/16" thickness and some of those units have been in use for better than 20 years. In the end its all about water care and maintenance. Monitoring your ph, nitrate, keeping it full of water and never below 140 degrees. Water gives up its absorbed oxygen at 180 and doesn't absorb it again till it drops to 140.140 degrees is also the magic number when water vapor in flue gas starts to condense in the fire box. So another reason to keep it above that temp. your fire box will be plenty solid with that material. If it where me, I would use it. Because I built my fire box out of 3/16 thick A70 and know that ill cut this thing apart to recycle the steel far long before anything fails.
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:post:
Great information. I hope others will read between the lines concerning operating temps! Makes more sense now why CB defaults their controls to 185 off / 175 on.
Thanks!
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I also want to add quick that its my opinion that The use of "boiler plate" in an outdoor wood burner is nothing more than a sales gimic that appeals to the uninformed. Asme rated plate is graded by its pressure and temperature capability. Even the lowest grade of asme cert steel is capable of far more than a owb can ever produce. Asme Temperature ratings state that SA36 is more than sufficient, and thickness is determined by operating pressure. Which I hope is atmospheric for anything home made. So necessary thickness is actually minimal. The only application where boiler grade steel should probably be used is in a gasifier, where temps call for at least SA 285-x but SA 516-xx would be best. Just my $.02 but something I wanted to throw out there because I see it over emphasized way to often.
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peacmar, great info there! :thumbup:
I also agree that the "boiler Plate" is an over used sales gimmick to persuade uninformed consumers.
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Thanks for the thumbs up guys, I've decided that that info will be a part of my informational thread. And not trying to jack your thread shane g just doing my best to help you make informed decisions. To elaborate a little on my previous response, and something tying consider when you get yours up and running. It may work to your favor to run your boiler all the way up to 200 degrees the first time you fire it. Then back the temp down to around 160-170 depending on what your controller differential is. I use a PID controller with thermocouple and have an adjustable differential but have found that if I run from 150 to 170 I get far better mpg so to speak out of my wood usage. I didn't notice my air handler running any more often even in the middle of January last winter when it was -25 and we also have a constant 15-45 mile per hour wind up on top of our hill with no wind breaks grown in yet. But lowering the temp range down from 180-190 I used about a third of a cord less of wood in Jan than I did in the 40 degrees warmer month of December. I know this is out there a ways yet but something to keep in mind for when the time comes. I wouldn't suggest any lower than 150 though, especially if you happen to have forced air, as your return water temps will be below 130 if your exchangers is sized right and you will need sufficient heat stored in the boiler to keep the overall temp from never going below 140.
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wow great info just the info i need looks like i am going with that steel then
ok when i put the pipes in for the forced air in the fire box some body on here said i should only have 20% of my air going under the fire and 80%blowing on the top side?? was planning on running 2" pipe
2 of them out of my blower motor box any idea on how to reduce the cfm in the pipe ??? maybe manual butterfly valves
thanks again for thi info main goal in life this week is to cut and bend firebox and hopefully weld this weekend and get pics of this on here
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I will draw up a sketch and take a picture to put up here. It's very simple though, fan blows into a box and box has two pipes going into the burn box. One high one low. The end of the pipe in the fan box has a round plate welded to the head of a bolt that goes through the fan box to the outside. The fan box is threaded so when you screw the bolt in it brings the plate closer to the end of the pipe until its closed, loosen the bolt and it backs aware from the pipe end and let's more air through. Very linear and very precise and easier to fine tune than a butterfly. jamb nut to lock it in place and both of your air pipes can be metered the same way. I too also believe that 20% under and 80% over is good. Ideal is 1/5 ratio so that's about right percentage wise.
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I will draw up a sketch and take a picture to put up here. It's very simple though, fan blows into a box and box has two pipes going into the burn box. One high one low. The end of the pipe in the fan box has a round plate welded to the head of a bolt that goes through the fan box to the outside. The fan box is threaded so when you screw the bolt in it brings the plate closer to the end of the pipe until its closed, loosen the bolt and it backs aware from the pipe end and let's more air through. Very linear and very precise and easier to fine tune than a butterfly. jamb nut to lock it in place and both of your air pipes can be metered the same way. I too also believe that 20% under and 80% over is good. Ideal is 1/5 ratio so that's about right percentage wise.
if you go and look at my build thread this is exactly how I built my air box.I can precisely control. Air flow in each chamber.works excellent.although I suggest to apply antisieze to the threaded rods due to creasote in the box that gets on the threads.
I would like to advise you to perhaps up size your air tube to something bigger than 2".I am running a 2x3" tube into mine.I sometimes wonder if a little bigger feed tube would improve performance any.
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Great suggestion jackel440, a picture is so much better than a sketch. And when you purchase or find your fan, use the outlet as a guideline for the air tube sizing. They are designed for optimal flow and if you figure out the surface area of the fan, you will know how large to.make your air tubes. The air tubes must all add up to be equal to or greater than the area of the fan. 2"x3" outlet is in the ball park of 170 cfm for a typical squirrel cage blower at no load air flow. One rule with blowers is the air velocity exiting cannot be faster than the tip speed of the blower wheel, as the wheel just can't push air any faster than its spinning. But 170 cfm is still a massive amount of air through a gasifier. One particular company only uses a pair of 50 cfm fans, on their 200,000 btu hr model. So 170 is quite a bit. Although, if you have a place to store it then let the heat roll out.
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:( :( :( our laser been down and ops are catching up on production so my little project got put on the back burner hope to start soon but here in VA its 70 degrees so thats helping my fuel bill but sucks that opening day of gun season starts sat and its freakin hot
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hi everyone
been a while since i posted had to put my stove on the back burner last year and this summer but things are coming together firebox built last week working on the water jacket this weekend here's a couple picks it is going to be a beast
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lol i posted wrong pic the mustang is not part of the stove here is the other pic thats my daughters car (my other money pit)
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well got another question i should be finishing my water jacket this weekend should i have a vent in the top of my water jacket or should i put in like a pop off valve or just leave it sealed but i'm thinking it will build pressure thanks for any help
getting cool here in virginia wont be long
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well here is another pic it's coming along looking for some help i was welding in my water connections for my circ pump but i put in 3/4 instead of 1" i am going to be going about 150 ft i can still run 1" line let me know your thoughts
also how should i vent my system
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I would just put in an overflow at the top
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1 inch pipe seems to be the standard. It is what I used to go 165 ft - one way. I don't think I would want to go with anything smaller. I put my vent on the storage tank, which is next to the boiler, and the vent is also the highest spot in the system.
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what do you guys recomend as far as a pump the run is going to be about 150' the stove will be about 6' higher than the exchanger and the exchanger is probaly going to be 100,000 btu also what is better for the hot water a sidearm or a plate type
thanks for all the help i am getting close
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please help
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i concur on the 1 inch min for pipe from boiler to home at 165 feet one way
there are folks on here who know better about side arms and plate exchangers but i would ask you if you are building your own furnace why not your own water exchanger? mine is a 12 inch pipe 2 feet long with an inlet and outlet for boiler water and a 1/2 inch 50 foot coil of soft copper wrapped up like a spring inside that, that my domestic water goes through. works great!
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i was going to but time waits for no one :bash: so i am just going to buy it my main concearns right now is getting the correct pump and what cfm my fan should be i am going to have one loop from boiler to heat exch to side arm or plate and back to boiler i have no clue where to go from there as far as pump size,components such as bleeders inline filters strainers ???? i am almost done with the stove and i am at the point where i need to order the other things to hook it up
thanks for any input
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Update
went in t work this morning on my day off to work on the stove got it all welded and pressure tested looks like it will hold water just need to finis up the door latch and it is on its way to the house will post some pictures in a day or so
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it is coming together finaly got it home got floor poured building almost framed got my pipe in the ground found a unknown septic tank what a pain in the #%$
most of my parts have come in
i went with a b&g pl-36 pump and a 20 plate exc for dmh gotta save a little more dough to finish though man all that stuff was high
here are some pics
i am moving the studs away from the door thats a little close
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any updates
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;D well today is the first day it has been running all day works good try to get some pics up