# Homemade and Engineered Gasification Boiler



## Born2burn

New to the forum,  but have been visiting for some time reading up on gasification boilers..  Thank you for all your post.

Wanted to share my gasification water heater that I built and is running on its second season now.  I don't like calling it a boiler because I am not making steam.  Anyway I did some simple calculations in my head for the size of the firebox, the secondary chamber and the heat exchanger on the backend.  It is a down draft gasser, I have a preheater for the primary air and the secondary air has a second air heater.  I have a 2" valve that I can control the secondary air for future o2 controller I would like to install.  The water to flue gas heat exchanger is a retired 200 gallon propane tank that I gutted and installed 13 tubes in that are 2" in diameter and 5 feet long. I use some 1/4 in chain for turbulators and welding a some pipe on the end so I could chuck a drill to the end and use the chain as a pipe cleaner also. The heat exchanger is a pressurized one to keep the o2 out of the water.  I have two 15 psi relief valve and one temp and pressure relief valves so the unit don't become a bomb in an event of over firing.  I also have a 195 degree high water temp cutout to completely shut power down.  UPS power backup for the water circulators to keep water moving in an event of power interruption.

I do achieve around 1500 to 1800 secondary flame,  the fire box will hold roughly 7 to 10 cubic feet of wood.  I get a continued 12 hour plus burn time.  I load it at 5 am in the morning and then 6pm at night typically.  I never let the water get below 150F and no hotter than 175F.  I heat 2600 square foot 1910 fairly good insulated 1 and 1/2 story house using heat coils in the furnace.  Also heat a 1200 square foot shop with radiant floor heat, will also be heating 3000 more square feet at 50F when I get my shop floor poured.  The wood gasser sits in a 20 by 23 poorly insulated old garage that is about 65F from heat loss from the wood gasser.  My flue gas temps range from 225F to 300F.

I will post some pics below, I could write about this thing all day.  I learned a lot from the build and had to tweet air flows for about a month before I got it to work properly.  Now I just load and go.


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## warno

Looks good.  Could I see how you hooked up that propane tank into the mix? I'm guessing that's your heat exchange tubes running through it?


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## hondaracer2oo4

Well done! Interesting approach with no water around the firebox, only in the self contained hx. Appears to be very efficient at moving the heat into te water if your flue temps are accurate. Are you having issues with the flue gasses collapsing and condensing in the hx at those really low temps? How did you measure them? Where are you located geographically and how much wood do you go through for your season? We love the pictures around here, if you have any more we would love to see them!


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## Born2burn

warno said:


> Looks good.  Could I see how you hooked up that propane tank into the mix? I'm guessing that's your heat exchange tubes running through it?


Yes it is.  The heat exchanger is sitting vertical on the back side of the gasser.  The gasses travel through the secondary chamber refractory lined (the bottom door) and then through the 13 tubes and then out the top of the flue which is the belled end that is removable for cleaning.  I will dig up a few more pics for you.  And thanks for the comments,  I was very discouraged at first when everyone said homemade gassers are won't work.


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## Born2burn

I did not like 170F water around the fire box because to me it is like burning a fire inside of an ice box.  To get temps correct in my opinion the fire box should be over 500F and be easily maintained for pyrolysis to occur.  I put 2 inches of plastec 85 refractory around the firebox except the top.  The top and the sides preheat my primary and secondary air.  My flue temp is measured by a thermocouple at the top of the belled end of the heat exchanger where the gases collect and go out the flue.  I believe it is fairly accurate.  I use a Rocks BBQ Stoker 2 to remotely monitor my temps.  I would really like to invest in a vesta controller for my gasser.  As for condensing,  it is not a problem until really below about 130F, I play it safe and run minimum water temp at 150F.  I do run about 10 to 20 percent moister wood.  The water returns com in the top 3/4 of the heat exchanger through an inside pipe to it can pick up heat along the way so the bottom of the heat exchanger does not get to cold. I'm located in the eastern part of Nebraska, winters are not to bad here but just bad enough!  I will post more pics when I get some time.


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## hondaracer2oo4

I agree with the cold firebox issues. Any creosote build up in the firebox? My G series is surrounded by water which means that even when the boiler is at idle the hot coals are still radiating heat inside the firebox and transferring some of that heat into the water jacket. I have a thin oily layer of creosote on the parts of the firebox that touch the water jacket. I thought that the manufacturers were shooting for around 350 flue temps because of the concern about condensing flue gasses if they went below that number. Maybe I am wrong. How many cords do you go through?


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## Born2burn

hondaracer2oo4 said:


> I agree with the cold firebox issues. Any creosote build up in the firebox? My G series is surrounded by water which means that even when the boiler is at idle the hot coals are still radiating heat inside the firebox and transferring some of that heat into the water jacket. I have a thin oily layer of creosote on the parts of the firebox that touch the water jacket. I thought that the manufacturers were shooting for around 350 flue temps because of the concern about condensing flue gasses if they went below that number. Maybe I am wrong. How many cords do you go through?


I believe last year I went through a lot, for sure 20 cords plus.  But I had about 25 to 30 on moisture for would.  I did condense out a little last year because my secondary combustion was hindered by the moisture.  The other day I did weigh the wood and out of 125lbs I got 13 hours plus still had a lot of charcoal in the bed.
Attached are some pics of the tubes and the flue where I take the temperature.  There is starting to have al little build up from some condensing.  I have only had about 4 startups so far this year from October 25.  So far I burned about 1.2 cords roughly.  I has only been in the 40F and now with snow it is 20F.  I forgot to mention I do heat all my hot water for the house, I have 6 in the family, lots of endless showering.
The firebox pic is what I loaded last night around 7pm and this is what was left about 8:30am this morning.
Oh and yes I do have the back side of the firebox is the heat exchanger wall.  I gets a nice shiny creosote on it and is does condense out during burns.  I work in a coal fired power plant and are flue temps are from 300F to 325F.  We burn 35 percent moisture coal too.  Never have anything condense.


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## Vinced

Nice build. Any pictures of the back before insulation? I'm curious how you joined the propane tank heat exchanger to the firebox/secondary burn tunnel?


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## warno

I'm interested in that connection as well.

More pitchers please!


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## hondaracer2oo4

20 full cords or face cords?!?! If that is 20 full cords I think you may have a problem somewhere. If your flue temps are that low that means you are getting the heat into the water so you are losing your btus somewhere else. What do you have for underground lines? Have you measured your temp loss from the boiler to the house?


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## Born2burn

This is what it looked like last year, I was in a hurry with winter on my door step.  I had tremendous heat loss from it radiating into the garage.  It was 80 or 90 in there when it was -5f outside and it was just a tin pole shed I uninsulated at the time.  I have about 1 degree heat loss with the variable speed bumblebee pump running at minimum and 0 degree loss at full speed, on a 100ft run.  According to my heat gun!  I do not have any of the pipes insulated in the garage and the house yet. The pipes underground the hots are separate from the cold ones, in a different housing pipe.  I have my own insulating material (proprietary) and  an air space between the material and the housing pipe which is buried 8' in the ground that is 55F.


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## Born2burn

hondaracer2oo4 said:


> 20 full cords or face cords?!?! If that is 20 full cords I think you may have a problem somewhere. If your flue temps are that low that means you are getting the heat into the water so you are losing your btus somewhere else. What do you have for underground lines? Have you measured your temp loss from the boiler to the house?


Oh and for the 20 full cords,  it is pretty much a guess, I know I burned 10 for sure that was in my wood shed but the res was cut as I went and blended, so I'm not sure exactly what I all burned!  I will try to keep a better record this year. I have lot and lots of wood at my dispose, I burn anything from pine to walnut.


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## hondaracer2oo4

Well it sounds like your not losing your btus into the ground. Just don't know how you managed to go through 20 cords with a gasser with low flue temps, it doesn't make sense to me. What were you heating with before and how much were you going through?


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## Born2burn

hondaracer2oo4 said:


> Well it sounds like your not losing your btus into the ground. Just don't know how you managed to go through 20 cords with a gasser with low flue temps, it doesn't make sense to me. What were you heating with before and how much were you going through?


I have a englander box stove I use to go through 7 cords a year with it.  That heated the 2600sq ft house!  That's all I used and maybe burned 100 gallon of propane for supplement when gone!  I believe I lost lots to inside the garage, because the sides of the gasser where not insulated.  That takes lot of btus to heat a 20x 23 drafty garage!  Plus I heat a 1200sq ft shop 12' sidewalls with one wall adjoining the 3000sq ft shop that is uninsulated yet.  So some more heat loss!


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## Born2burn

How much wood do other gassers use?


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## maple1

I use maybe around 6 cords per year. That's a 2700 sq.ft. 20 year old two storey, with another 1500 in unfinished basement, where the boiler is.

Interesting having the primary firebox not water jacketed (except for the back where the tank is) and not just the secondary chamber. I don't think I've seen that in a ('factory') downdraft gasser before. That might make return temp protection not so much a concern also.

Nice work!


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## huffdawg

maple1 said:


> I use maybe around 6 cords per year. That's a 2700 sq.ft. 20 year old two storey, with another 1500 in unfinished basement, where the boiler is.
> 
> Interesting having the primary firebox not water jacketed (except for the back where the tank is) and not just the secondary chamber. I don't think I've seen that in a ('factory') downdraft gasser before. That might make return temp protection not so much a concern also.
> 
> Nice work!



Do u heat your domestic hot water too?


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## maple1

Yes. Most of the time.

Last summer I decided not to burn wood for DHW, so turned the electric water heater on. I burned all summer the two summers before that, and when I was doing that I was burning up junk wood. But whenever I'm burning wood, I'm heating DHW.


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## Tennman

Seeing your design and fab skills I just wanted to give you a big congrats. Great seeing creativity and perspiration come together solve a problem. I'll bet your pretty successful in your chosen profession. Congrats


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## maple1

Not seeing a combustion fan. So this is natural draft? That, I can appreciate.


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## hondaracer2oo4

Obviously the amount of wood used by anyone is dependent on heat load. Your house isn't going to be a huge load since you used 7 cords in a wood stove and heated it fine. The shop is a draw but I doubt you heated it at 70 degrees 24x7. You certainly lost a lot to the boiler room if it was 90 degrees in there. I used to go through 12 or more cords with my conventional owb heating 2700 sqft 220 year old decently insulated 2 story colonial and my dhw for two in New Hampshire. This is my first year with the gasser but I should be in the range of 6-7 cords at the end of the season judging by my consumption so far.


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## Karl_northwind

I like it!  I've seen a lot of boiler designs, and if you're going to have it in a heated space, I think the non-water jacketed option is great for a homebuilt boiler. The HX you built there is a nice setup.  I think I'd have gone bigger on the flue tubes, (you can turbulate or not, but you can't make them bigger) but other than that, I have nothing I'd add.  I have to wonder if the water jacketed fireboxes on the commercial boilers make shutdown easier (by removing heat from the firebox and helping control the  off-gassing of your fuel wood. )  
without return protection, the low moisture content wood is critical.  
  I thought about doing something similar once upon a time, because I can weld a water tight circle, but am not sure about long straight welds.  what with warping and such.  I though a 100 gal LP tank would be a good starting point.


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## Born2burn

hondaracer2oo4 said:


> Obviously the amount of wood used by anyone is dependent on heat load. Your house isn't going to be a huge load since you used 7 cords in a wood stove and heated it fine. The shop is a draw but I doubt you heated it at 70 degrees 24x7. You certainly lost a lot to the boiler room if it was 90 degrees in there. I used to go through 12 or more cords with my conventional owb heating 2700 sqft 220 year old decently insulated 2 story colonial and my dhw for two in New Hampshire. This is my first year with the gasser but I should be in the range of 6-7 cords at the end of the season judging by my consumption so far.





maple1 said:


> I use maybe around 6 cords per year. That's a 2700 sq.ft. 20 year old two storey, with another 1500 in unfinished basement, where the boiler is.
> 
> Interesting having the primary firebox not water jacketed (except for the back where the tank is) and not just the secondary chamber. I don't think I've seen that in a ('factory') downdraft gasser before. That might make return temp protection not so much a concern also.
> 
> Nice work!


Thanks I wanted to do a low psi system and for me and my time it was the best approach without doing a bunch of stay bolts on flat steel!


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## Born2burn

T


Tennman said:


> Seeing your design and fab skills I just wanted to give you a big congrats. Great seeing creativity and perspiration come together solve a problem. I'll bet your pretty successful in your chosen profession. Congrats


Thanks, I do love what I do and I love building things. I like burning wood and wanted a new challenge.  Plus It is good exercise which a lot of people pay to do. Now I just have to master controls and make things more efficient.


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## Born2burn

My primary air fan uses about 67 watts, hey I was in a pinch I hate to change it just works to well.  My actuator is fail closed so it almost eliminates natural draft.  I would like a better air cut off if anyone has any ideas!


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## Born2burn

Hope this helps with the Heat exchanger relation with the secondary burn and the primary, my other construction pics air on the other PC I will get soon.  I have a piece of carbon steel in the secondary chamber just to see how long it last in these temps, see in pic.


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## Born2burn

Hope this helps with the Heat exchanger relation with the secondary burn and the primary, my other construction pics air on the other PC I will get soon.  I have a piece of carbon steel in the secondary chamber just to see how long it last in these temps, see in pic.


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## Born2burn

Born2burn said:


> Hope this helps with the Heat exchanger relation with the secondary burn and the primary, my other construction pics air on the other PC I will get soon.  I have a piece of carbon steel in the secondary chamber just to see how long it last in these temps, see in pic.


The fire box pic above, I had to modify the primary air tubes they are higher now and the bottom of the pa firebox I v shaped with refractory to the center nozzle, and the nozzle is a little bigger now in length.  I will get a new pic on a nice day.  I have at least 700lbs of dense refractory on the bottom, sides and front of the pa box.  It stays hot for a long time.


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## Born2burn

Video of secondary combustion, this never gets boring to me!


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## warno

Very nice setup. 

I don't know why, but the glowing red chain turbs are funny to me.


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## brenndatomu

warno said:


> Very nice setup.
> 
> I don't know why, but the glowing red chain turbs are funny to me.


I found this statement funny  
Nice build Born2!


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## Whitepine2

Born2burn said:


> Video of secondary combustion, this never gets boring to me!
> 
> 
> 
> 
> 
> 
> SWEET
Click to expand...


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## Born2burn

warno said:


> Very nice setup.
> 
> I don't know why, but the glowing red chain turbs are funny to me.


Thanks, this is the first season for the chains, I am sure the exposed glowing red ones will eventually burn up!  I made them a little long so I could smack the around a little during the season to knock a little ash off.


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## Born2burn

Finally got a inside secondary combustion temp reading, my other probe on the back under the heat exchanger gets to about 1500F but it's not in the flame.  The k probe was in the middle off the fire and it pegged out at 2000F. The meter only goes that high, the probe is too til 2200F !  Sorry for the vertical video!


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## Karl_northwind

Born2burn said:


> Finally got a inside secondary combustion temp reading, my other probe on the back under the heat exchanger gets to about 1500F but it's not in the flame.  The k probe was in the middle off the fire and it pegged out at 2000F. The meter only goes that high, the probe is too til 2200F !  Sorry for the vertical video!



What sort of Flue gas temps do you see at the outlet? that'll give us some idea of the efficiency.  I would think under 400.  Your draft blower looks pretty big, resulting in more of a forge in that lower area.  If I remember right, at 2300 F you start fusing nitrous oxides, so backing down on the burn rate might be a good thing, both to reduce cycling, and reduce secondary temps.  2000F is plenty high to burn off everything in wood as I remember.  don't have time to look things up right now.


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## Born2burn

Karl_northwind said:


> What sort of Flue gas temps do you see at the outlet? that'll give us some idea of the efficiency.  I would think under 400.  Your draft blower looks pretty big, resulting in more of a forge in that lower area.  If I remember right, at 2300 F you start fusing nitrous oxides, so backing down on the burn rate might be a good thing, both to reduce cycling, and reduce secondary temps.  2000F is plenty high to burn off everything in wood as I remember.  don't have time to look things up right now.


At the time of this video my temp on the outlet was 280F.  My water temp was 178F and the inlet combustion air temp was 74F prior to getting preheated to 300F.  Outdoor temp about 10F so it had a decent load on it.  I would have to agree on the fan though, it has 3 speeds and I use to run it on the highest but works much better at the lowest. I thing the fan on high is rated for 250~
CFM.   I plan on slowing it down further and try to find a sweet spot so it has more time on than off.  Surprisingly I still maintain sort of a pilot flame in the burn chamber when it is off and this also extends the down time!  I have had it down for 3 hours before on a warm day with no load and it takes off again.


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## mx842

Are those black iron pipes you are using for your air pipes? I was wondering how that would hold up in a firebox like you have them set up. I ran some 1/8" square tube in my firebox for air tubes in my old makeshift updraft boiler I was working on and they burned out pretty quickly...(.less than one season). I replaced that with 1" schedule 40 black iron to get through the rest of the season and when I scrapped her they didn't look as bad as the sq tube but I could see they were taking a beating from just the little time it was in there.


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## Born2burn

mx842 said:


> Are those black iron pipes you are using for your air pipes? I was wondering how that would hold up in a firebox like you have them set up. I ran some 1/8" square tube in my firebox for air tubes in my old makeshift updraft boiler I was working on and they burned out pretty quickly...(.less than one season). I replaced that with 1" schedule 40 black iron to get through the rest of the season and when I scrapped her they didn't look as bad as the sq tube but I could see they were taking a beating from just the little time it was in there.


Yes they are 2" schedule 40, this will be the last season for them.  I plan on replacing them with some 253MA high heat stainless.  253MA takes 2000F for long service.  Pricey but I need it to last! Also the pic with the air tubes has changed they are higher and the floor is v shaped to the nozzle slot.  I did see one of the air tubes is starting to break down


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## Born2burn

Born2burn said:


> Yes they are 2" schedule 40, this will be the last season for them.  I plan on replacing them with some 253MA high heat stainless.  253MA takes 2000F for long service.  Pricey but I need it to last! Also the pic with the air tubes has changed they are higher and the floor is v shaped to the nozzle slot.  I did see one of the air tubes is starting to break down


V Shaped with refractory I meant!


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## warno

Do you have any pictures of your firebox with the fire brick laid in?


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## Nofossil

I love this kind of project - nice work. My brother built a ultra high-efficiency gasser (condensing!) many years ago. Expect to find a few problems - especially material issues like the schedule 40 pipes, but it's great to be able to make something with your own hands.

I'd be interested to see wood consumption as you get it tightened up. Like others, I think it seems higher than it should be, especially given your flue temps (I'm struggling to stay below 500). Are you seeing visible smoke or any sooty flue deposits?


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## brenndatomu

Born2burn said:


> I plan on replacing them with some 253MA high heat stainless. 253MA takes 2000F for long service. Pricey but I need it to last


I used regular ole 1" 304 SS pipe...works fine. The black iron that I started out with lasted a lil less than one heating season


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## FinsterCT

Wow Man! seriously impressed! I'm an engineer (EE) and grew up in a house where I knew how to weld and use a Milling Machine like a boss before I got my drivers license. After seeing your pics, only thing that comes to mind is the scene from the movie Waynes World...."were not worthy! were not worthy"  Nicely Done!

I bought my Gasser... I was too chicken to put a homebuild in my basement ...I've often thought I might try building a second gasser one day (outside)... I've looked at fabrication techniques with refractory, and most talk about complicated curing techniques... cure at such a temp for so long then this temp for so long etc.... what kind of refractory did you use????

I saw somewhere back a few posts that you were learning /trying different controls stuff... I'm pretty solid there...Happy to offer up advice if you get stuck on anything!


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## Born2burn

Nofossil said:


> I love this kind of project - nice work. My brother built a ultra high-efficiency gasser (condensing!) many years ago. Expect to find a few problems - especially material issues like the schedule 40 pipes, but it's great to be able to make something with your own hands.
> 
> I'd be interested to see wood consumption as you get it tightened up. Like others, I think it seems higher than it should be, especially given your flue temps (I'm struggling to stay below 500). Are you seeing visible smoke or any sooty flue deposits?




Took a video tonight for you, probably wood have been better during the day!  I slowed the combustion fan down today some more, I was reaching over 2000F on secondary combustion, it is helping with short cycling.  I don't have any storage, bit looking into it.  As fare as deposits in heat exchanger, not much see pics in the beginning of this thread, that was after about a month or so run time.  Keep in mind my heat exchanger tubes are about 5 foot long and there are 13 of them.  My velocity is pretty slow allowing for good heat transfer and my wood moisture is about 15 now!


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## Born2burn

Here is a video of a much lower speed on the combustion fan.  I have found out  it works well at lower speeds but seems to take about 5 minutes to get secondary combustion again, so for tonight I am on speed 3 on my controller and 1 on the fan.


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## Born2burn

FinsterCT said:


> Wow Man! seriously impressed! I'm an engineer (EE) and grew up in a house where I knew how to weld and use a Milling Machine like a boss before I got my drivers license. After seeing your pics, only thing that comes to mind is the scene from the movie Waynes World...."were not worthy! were not worthy"  Nicely Done!
> 
> I bought my Gasser... I was too chicken to put a homebuild in my basement ...I've often thought I might try building a second gasser one day (outside)... I've looked at fabrication techniques with refractory, and most talk about complicated curing techniques... cure at such a temp for so long then this temp for so long etc.... what kind of refractory did you use????
> 
> I saw somewhere back a few posts that you were learning /trying different controls stuff... I'm pretty solid there...Happy to offer up advice if you get stuck on anything!





FinsterCT said:


> Wow Man! seriously impressed! I'm an engineer (EE) and grew up in a house where I knew how to weld and use a Milling Machine like a boss before I got my drivers license. After seeing your pics, only thing that comes to mind is the scene from the movie Waynes World...."were not worthy! were not worthy"  Nicely Done!
> 
> I bought my Gasser... I was too chicken to put a homebuild in my basement ...I've often thought I might try building a second gasser one day (outside)... I've looked at fabrication techniques with refractory, and most talk about complicated curing techniques... cure at such a temp for so long then this temp for so long etc.... what kind of refractory did you use????
> 
> I saw somewhere back a few posts that you were learning /trying different controls stuff... I'm pretty solid there...Happy to offer up advice if you get stuck on anything!


Thanks!  I used plastec 85p for the primary firebox, I pounded the sides and the floor and formed it into a V shape to the slot in the floor that is the nozzle. The secondary chamber is just refractory block from Menards and the nozzle refractory is castable  refractory with needles!


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## Born2burn

warno said:


> Do you have any pictures of your firebox with the fire brick laid in?



Warno, this video is all I got, I used platec 85p with needles.  I used this because it it poundable forms like playdoe and hardens when fired.  I used this because i got it for free because it was past its 6 month shelf life!  It is about $100 for 55lb  and sad to say I put in I would say 800lbs.


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## warno

Thanks for the video. That's some interesting looking stuff.


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## mx842

I was wondering how regular fire brick would hold up in all three places. When I was playing around with my old up draft gasser I made a fire chamber out of fire brick. I never could get the secondary air right but I was getting 2000 degree temps just as it entered the chamber. I was surprised when I scrapped the whole project to see that it was still very solid, in fact I had to beat the heck out of it to get it out when I tore it apart to rework it the way it is now. Of-course that was only just one season of burning but the fire brick that in on the bottom and sides of the stove has been in there for like 10 years.


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## Born2burn

mx842 said:


> I was wondering how regular fire brick would hold up in all three places. When I was playing around with my old up draft gasser I made a fire chamber out of fire brick. I never could get the secondary air right but I was getting 2000 degree temps just as it entered the chamber. I was surprised when I scrapped the whole project to see that it was still very solid, in fact I had to beat the heck out of it to get it out when I tore it apart to rework it the way it is now. Of-course that was only just one season of burning but the fire brick that in on the bottom and sides of the stove has been in there for like 10 years.





Here is one of the side bricks there was about 5 of These like this with one season, the second layer was normal.  I the ones on the floor where not as bad surprisingly. I suppose the ash cover helps a little to. I figured that this was not bad after one season, the top piece which I casted with needles is holding up well! The casting pic the the nozzle that lays on top the side brick in the chamber.


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## Nofossil

Very nice. Where in the combustion chamber are you measuring temperature? I tried measuring in the actual flame zone, but it was way to hot. My thermocouple maxed out at 2500, and it was hotter than that. I now measure 'around the corner' - out of the direct flame and nect to the water jacket, but before the HX tubes. Mine are only 18" :-(


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## Born2burn

Nofossil said:


> Very nice. Where in the combustion chamber are you measuring temperature? I tried measuring in the actual flame zone, but it was way to hot. My thermocouple maxed out at 2500, and it was hotter than that. I now measure 'around the corner' - out of the direct flame and nect to the water jacket, but before the HX tubes. Mine are only 18" :-(


Measure the secondary right under the heat exchanger, about 18" from the nozzle it usually gets to another 1500F. I was just curious on what it was getting right under the nozzle and yeah my meter pegged out at 2000F couple good until 2200F.  When I have long run times like for me is 40 minutes ( I have no storage)  the fire brick and ash deposits appear white which looks pretty hot to me!  I do a little blacksmithing and the secondary chamber works pretty good to get the steel cherry red


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## cumminstinkerer

Born2burn said:


> Measure the secondary right under the heat exchanger, about 18" from the nozzle it usually gets to another 1500F. I was just curious on what it was getting right under the nozzle and yeah my meter pegged out at 2000F couple good until 2200F.  When I have long run times like for me is 40 minutes ( I have no storage)  the fire brick and ash deposits appear white which looks pretty hot to me!  I do a little blacksmithing and the secondary chamber works pretty good to get the steel cherry red


I'm new to the site but I'm pondering building a gasser, I'm currently running a homemade conventional boiler that I'm gonna mod for now and run a couple more years while I'm working out the gasser. my first mod to my current boiler is to add a firebrick baffle and secondary air, I would sure like your input on my plans. not sure if you can pm on here but if you can please do Thanks


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## slowzuki

The cold water fuel chamber is on purpose in most gasifiers to slow down pyrolysis.  With insulation, the temperature in the fuel box is more variable therefore the rate of gasification is more variable.  This means more messing with primary and secondary air to get it tuned.

Also making most of the chamber cold for the same size gasification rate overall means a smaller, hotter zone of gasification and less tars/long chain smoke is made which means you don't need as long of dwell time in a tunnel to break those back down and completely burn them.



Born2burn said:


> I did not like 170F water around the fire box because to me it is like burning a fire inside of an ice box.  To get temps correct in my opinion the fire box should be over 500F and be easily maintained for pyrolysis to occur.


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## Born2burn

I would imagine this is why they want water jacketed gasser to run flat out high fire until they are out of wood.  If it would sit idle too long the heat would be gone from the primary chamber and then it would take to long to get up to temps without secondary flame.

I needed to be able to run at least 12 hours and I did not want to be restarting a fire all the time.  I usually start a fire 2 -3 times a season and I have been loading every 13 hours.  My unit does idle a lot but always has a small pilot from the idling gasses still gassing off from the wood in the secondary chamber.  The disadvantage to my setup is I loss heat to the garage I have the gasser in, so it is always heated even when I don't need it to 70F all the time.  So I burn more wood than a jacketed gasser but I can live with that.  I thought about adding storage but I don't really see the benefit in my situation (yet)





slowzuki said:


> The cold water fuel chamber is on purpose in most gasifiers to slow down pyrolysis.  With insulation, the temperature in the fuel box is more variable therefore the rate of gasification is more variable.  This means more messing with primary and secondary air to get it tuned.
> 
> 
> 
> 
> Also making most of the chamber cold for the same size gasification rate overall means a smaller, hotter zone of gasification and less tars/long chain smoke is made which means you don't need as long of dwell time in a tunnel to break those back down and completely burn them.[/QUOT).[/


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## Born2burn

Another corny video of my gasifier, I apologize I am not the best video/talker!  I just loaded with half pallets and split wood.


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## Karl_northwind

what did you do to meter your primary/secondary air?  and I agree you could definitely slow down the fan!  Long slow burn times is what to shoot for.  for a homemade, one of the nicer setups I've seen.


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## Fred61

Nice job!
By the way, you didn't happen to find a piece of refractory in your ashes after that pop did you? Ceramics don't like uneven temperatures so limiting run time with the door open should be kept at a minimum.


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## Born2burn

Right now the i have no control over primary air. It s just limited by the hole size of my primary air tube.  This summer I am going to replace them with stainless and ad a valve for primary air. This way I can control the secondary flame better. The secondary I have a 2" valve normally all the way open, but after the volital gasses are burned off it would be better to cut the air back then.  I have slowed the fan down and got slightly better burn times but it tends to leave more heavy ash in the primary chamber.  Last night was about 8F as a low and I got 13 hours out of it and about 6" of coals left this morning.  My house is at 74F and the shop is at 70F 
See the trend, this is how much it normally cycles


Karl_northwind said:


> what did you do to meter your primary/secondary air?  and I agree you could definitely slow down the fan!  Long slow burn times is what to shoot for.  for a homemade, one of the nicer setups I've seen.


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## Born2burn

Thanks I am glad it works as good as it does because I would never here the end of it from my wife if it did not!
I did not see anything broke, the pop did catch me by surprise!  I have had a nice poof before when I opened the primary door and once enough o2 got in it ignited and about burned some whiskers off.  I try not to open the primary door only when I have too!




Fred61 said:


> Nice job!
> By the way, you didn't happen to find a piece of refractory in your ashes after that pop did you? Ceramics don't like uneven temperatures so limiting run time with the door open should be kept at a minimum.


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## Nofossil

Born2burn said:


> View attachment 174692
> 
> See the trend, this is how much it normally cycles


That's really cool! I'll guess that if you could do variable control rather than on/off, you'd get even better performance.


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## Born2burn

3rd season on my homemade boiler and this, just happened on Monday!

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## Born2burn

Born2burn said:


> 3rd season on my homemade boiler and this, just happened on Monday!
> 
> Sent from my S60 using Tapatalk
> View attachment 196128
> View attachment 196129







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## Born2burn

Was heating 6800 square feet this year!  Was working great, had wind storm and fire Marshall says it was electrical service overhead that caused it!  Sad day for me!

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## velvetfoot

Wow, that sucks!


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## E Yoder

I'm sorry. A lot work lost.
Will you build a new one?


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## mx842

Man like velvetfoot said that really and truly sucks bad!! Did it destroy the whole boiler? Well at least it's almost spring so hopefully you guys don't freeze to death before it finally gets here. Hopefully you can salvage some of it so it's not a total loss. My thoughts and prayers are with you.


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## cumminstinkerer

I sent born2burn a text but wanted to say it here too, This is terrible. when something like this happens you loose a piece of you. I want to than Born2Burn for all of his help with my project and extend to him that if there is anything that he needs from me I will be glad to assist in anyway possible.


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## Born2burn

mx842 said:


> Man like velvetfoot said that really and truly sucks bad!! Did it destroy the whole boiler? Well at least it's almost spring so hopefully you guys don't freeze to death before it finally gets here. Hopefully you can salvage some of it so it's not a total loss. My thoughts and prayers are with you.


I definitely overheated it, I am up in the air on rebuilding, insurance said they will cover it.  Not sure what to go with yet a garn  maybe, I heat alot and I want it in a separate building but not outside unit


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## Born2burn

E Yoder said:


> I'm sorry. A lot work lost.
> Will you build a new one?


I might build a new one, I hate to start the learning the unit all over again.  Lot of work down the tubes

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## E Yoder

Yeah. I hate what happened. I enjoy those do it yourself threads. But you're right, each design has a lot of nuances and you can burn up a lot of time tweaking. 
My brother is burning a chip boiler from Heatmaster and this is the first year. It works well but a learning curve on settings, fuel types, etc. Lotta time invested.


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## lazeedan

Man that sucks! That looked like a nice build!


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## Born2burn

lazeedan said:


> Man that sucks! That looked like a nice build!


Thanks,. I would be ready to go burn again but even if I get a new gasser I have no split wood for next season.  Log splitter burned, silvy chain sharpener, chains all burned up.  Going to take awhile to get back into it.  I still have two saws yet.

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## lotawood

Can you get the log splitter and silvy covered with insurance?

Sorry to hear of all the fire damage with you and others with wildfires in the region.  Good luck.  Hang in there.


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## Born2burn

lotawood said:


> Can you get the log splitter and silvy covered with insurance?
> 
> Sorry to hear of all the fire damage with you and others with wildfires in the region.  Good luck.  Hang in there.


Sound like it will be covered, even though the splitter and boiler are homemade.  I am having trouble finding a good gasser that will heat 6800 square feet and domestic hot water.  I know the garn wood but I need a comparable downdraft model.


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## E Yoder

Heatmaster G400 is good up to 8,000 sq ft
A couple guys running G2's are heating 6,000.


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## jmur1

I was reading through your heater build and then came across the end.  Terrible!  I cant believe that was the end!.  
Very impressed with that build.  Did you move to a manufactured unit?  I am considering a build of my own - I built a processor (it can be seen in this forum - "Wood processor on the slide"), and would like to simplify my wood requirements  I have to say I use a fireplace insert now and find that we use only 3 bush cord a year to heat 1800 sq ft with the insert.  We have 2 space heaters to heat baby rooms.  It seems like the gasification heater would work well but still uses alot more wood. I am burning premium split hardwood ash/cherry/beech.  Any overall comments?  Again - hats off to your build and I hope things worked out for you!


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## brenndatomu

jmur1 said:


> I was reading through your heater build and then came across the end.  Terrible!  I cant believe that was the end!.
> Very impressed with that build.  Did you move to a manufactured unit?  I am considering a build of my own - I built a processor (it can be seen in this forum - "Wood processor on the slide"), and would like to simplify my wood requirements  I have to say I use a fireplace insert now and find that we use only 3 bush cord a year to heat 1800 sq ft with the insert.  We have 2 space heaters to heat baby rooms.  It seems like the gasification heater would work well but still uses alot more wood. I am burning premium split hardwood ash/cherry/beech.  Any overall comments?  Again - hats off to your build and I hope things worked out for you!


Link...
https://www.hearth.com/talk/threads/i-built-a-crazy-wood-processor.163447/


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## SpaceBus

This thread was really exciting until the end... Awesome design and very inspiring .


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## MetalMan23

Shoot, I was just reading this I was getting excited, I wanted to build one for myself, anyone know how the OP made out? 

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