Didn't sleep well, Epiphany or Nightmare?

[shortline]

I've got to stop falling asleep reading this forum. What do you all think about the possibility of getting a significant secondary burn into the oil gun port of an old Multi-fuel HS Tarm OT50 from my Seton180. I chose the Seton to be a biomass burner with it's large door and tons (literally) of refractory permitting the fire to achieve high enough temperatures for complete combustion. I have access to lots of pallet wood. The problem with burning it is -- that it is too volatile. Sparke is working on on a secondary air intake for his greenfire, which I think will be a big help, but still wonder if I can get complete combustion? I think a secondary burn with properly controlled air would be optimum. A controllable draft induction would be necessary. I need to contact NoFossil about the possibility of a New World lambda controller. My unknown is -- can I ignite and maintain a secondary combustion from the cooled flue gases from my Seton? I think I'll try a catalytic converter first to prove the idea, than source some ceramic for the bottom of the Tarm should I be able to maintain a steady burn in the CC. I probably will have to add a propane ignitor as well to jump start the process. The other aspect I like about this idea is the Tarm holds 90 gallons of water, if I separate the seton hx and the Tarm from my 1000gal storage and load(home) to maintain optimum temperatures for combustion and heat exchange, should cut down on hx cleanings. What da ya think? Am I crazy or inspired? :coolsmile:

 

[Jesse-M]

The Setons simplicity is it's biggest plus....this idea sounds complicated. Good luck,and give us a build thread if you do it.

 

[benjamin]

can I ignite and maintain a secondary combustion from the cooled flue gases from my Seton? :

No. None of the boilers I've read about allow the gas to cool before the secondary combustion chamber, there is always a short path to the secondary combustion location and no steel or water in that path. If you want to build a new furnace design, save yourself a lot of work and design it from scratch.

 

[Nofossil]

I think the challenge is getting consistent woodgas. Cars that run on woodgas cool it down before burning it, so I suspect it's possible. Getting too much extra air could dilute it enough to make ignition difficult.

I bought an automotive wideband lambda sensor - might work though I don't know if there's any magic required to get it to live in a flue gas environment.

 

[pybyr]

For a separate burn of cooler woodgas you might well need a secondary source of ignition -- with the woodgas-in-engine scenario, it's done with either spark ignition or, if in a compression-ignition engine (diesel), a tiny injection of "pilot" fuel.

 

[shortline]

I think the challenge is getting consistent woodgas. Cars that run on woodgas cool it down before burning it, so I suspect it's possible. Getting too much extra air could dilute it enough to make ignition difficult.

I bought an automotive wideband lambda sensor - might work though I don't know if there's any magic required to get it to live in a flue gas environment.

yeah, will have to control the air for both the primary and secondary burns. Choking off the primary burn to ensure enough wood gas to maintain the secondary burn. My problem is -- I know nothing about lambda sensors, chemically or electrically! Can you point me to some remedial study sources.

 

[shortline]

For a separate burn of cooler woodgas you might well need a secondary source of ignition -- with the woodgas-in-engine scenario, it's done with either spark ignition or, if in a compression-ignition engine (diesel), a tiny injection of "pilot" fuel.

I'm thinking that once the catalytic converter and/or ceramic mass gets up to ignition temperature that the continuing combustion of the wood gas will maintain those temperatures and insure continual combustion until the fuel load is depleted. Also thinking a propane burner before the ceramic burner would get the secondary burn jump started. Of course all of this still in the dream phase -- "speculation". :smirk:

 

[Nofossil]

Don't know that a catalyst would survive. Secondary combustion is a really hot and hostile environment.

 

[shortline]

Don't know that a catalyst would survive. Secondary combustion is a really hot and hostile environment.

I was hoping for 1 season out of a catalytic coverter just to prove the idea, than molding a custom ceramic tunnel for the bottom of the TARM if I could maintain constant secondary burn. I think the biggest hurdle will be lambda sensors and controller to control the air induction for both combustion chambers. Up for a new challenge? No rush, I won't try this till the 12/13 heating season. Although I'd be up for sensor trials next season to get some data for accurate sensor placement & sensor choice. I need to crawl before walking.

 

[shortline]

can I ignite and maintain a secondary combustion from the cooled flue gases from my Seton? :

No. None of the boilers I've read about allow the gas to cool before the secondary combustion chamber, there is always a short path to the secondary combustion location and no steel or water in that path. If you want to build a new furnace design, save yourself a lot of work and design it from scratch.

Great idea! I think I'll start my R & D with two 30 year old natural draft boiler designs. One that could burn oil or coal, but had too much water jacket to allow the fire to get hot enough to burn any wood but dry kindling. And another that was designed to burn large unsplit blocks of softwood at very high temps, tons of refractory and very little water. Add some water storage, forced draft, electronics, and a biomass stocker to complete the 21st century boiler model and I believe I will have a boiler to put the Arabs out of the heating oil business!