I have a Brunko wood burning add-on furnace. I also have a Beckett AFG oil gun with an asbestos burn canister. The oil gun assembly would fit nicely onto the furnace,(with a simple modification to feed door) with the flame at the upper heart of the wood burn chamber. I like the idea of burning whatever is on hand, (wood/bio) but I wonder if there will be a significant loss of efficiency with the bio set up, so as to preclude the idea? Comments, suggestions? Thank you.
I sure hope this idea works, I am making just such a conversion but the Beckett burner is being thoroughly modified into a syphon-feed type burner to burn straight heated vegoil or used motor oil.
Efficiency -- I would think the only difference in heat loss between having the oil burner in a hot-air furnace or a boiler designed for the oil burner, verses a wood furnace, would depend almost entirely on how well each unit is insulated. there will be some differances due to fire box design or flue design but these differances are present even between similar oil burner furnaces/boilers.
All of the wood burning furnaces that I have measured have had fireboxes that were deeper than any of the oil furnaces or boilers so the fact that the length of the flame from an oil burner that is burning either biodiesel or vegoil is a bit longer than when burning fueloil is not a problem. All the fuel is burnt inside the wood furnace so all the heat will be transfered, the amount of heat from the oil burner will depend simply on how much oil you burn.
I am making up a new furnace door to accept the oil burner, I am mounting the burner unit using an adjustable mounting ring placed on the flame tube, this allows the flame end of the fire tube to project only a couple inches inside the wood furnace, this allows the door to swing open without being hindered by the flame tube protruding to deep inside the furnace.
The only other modification anticipated is to add a removable sheetmetal tray that lays on the ash grate in the bottom of the furnace, this tray will have an inch or so of sand in it to collect any unburnt fuel that may occur due to burning the thicker fuel.
Asbestos burn canister -- I am not familiar with this, please describe this a bit more.
Location: fisher,illinois,usa | Registered: June 03, 2003
The asbestos burn canister is a round, open top shape, which accepts the gun nozzle into the side. It circulates the flame throw, and eventually directs it vertically upward. I'm sure both yours, and my ideas will work just fine. The only penalty I see will be a loss of efficiency due to the different heat exchanger designs. The wood burner iron box relies on the fire, fire brick, and hot coals for heat transfer. The oil burner iron chamber is tall, round, and has additional side heat exchangers for the flue gases.
I burn clean,dry,B100 from a warm holding tank. (60 degrees) I've reduced the size of the nozzle from .75 to .65. This gives a clean burn (no smoke) and better burn rate (gal/hr). It cycles reliably, no other mods.
I do this type of work for a living and I am curious what you guys are doing for controls. Also with a burner a barometric damper is typical. However with a wood stove it is not. Wood stoves can leave flammable residue in the chimney (creosote) burners do not. I understand what your trying to do, and it seems like a good idea but maybe because I have to deal with building codes and inspectors these are the first things that come to mind. And I was wondering how you are addressing these issue's.
Originally posted by 51fitter: I do this type of work for a living and I am curious what you guys are doing for controls. Also with a burner a barometric damper is typical. However with a wood stove it is not. Wood stoves can leave flammable residue in the chimney (creosote) burners do not. I understand what your trying to do, and it seems like a good idea but maybe because I have to deal with building codes and inspectors these are the first things that come to mind. And I was wondering how you are addressing these issue's.
Just the answer I was looking for, and actually, I had already answered my own question. First off, I hate inefficiency. Secondly, it's very easy, and safer, to just change out the stoves. Luckily, duct work is the same size for either, and the oil furnace has controls, fan, and baro damper. I found a lady, tired of fuel oil bills, (she went to natural gas) who gave me the whole set up. Thanks for replies.
Raften -- Oil furnace nozzles are rated in GALLONS/HOUR.
51fitter -- I have installed a barametric damper with my current self-designed veg drip burner that has warmed my house for the last 3 winters, the new forced air heavy oil burner that is going into the wood furnace in the shop will have all the normal control features plus a few more needed to burn heavy oil, including a draft control.
The primary burner control is a Honeywell R7184U with the normal optical flame sensor to control startup, flameouts, and multiple restart attempts, it is controlled from a normal room thermostat. I am using the pre-purge period to start the ignition spark and open the syphon air solenoid to charge the nozzle block with fuel, the post-purge period will shut off the fuel and blow the nozzle block free of fuel to eliminate any liquid fuel in the heater block or nozzle passages in the attempt to reduce coaking due to heat soaking. There is a PID temperature control unit for the 500 watt heater cartridge in the ckburners.com syphon nozzle conversion block used for the final heating of the heavy fuel just prior to entering the syphon spray nozzle proper. There is another simple snap action temp switch and 250 watt cartridge heater being used to preheat the heavy oil to approx 120 deg f in a 1 quart supply tank just prior to the oil being drawn into the nozzle block. This small preheat tank also has a float switch that opens/closes a fuel supply solenoid valve to hold the syphon fuel level relatively constant (within a half inch, anyway), this places the syphon nozzle fuel level about 5 inches below the nozzle). The heated 275 gallon gravity feed fuel supply tank is located in the second story loft of the shop. There are also snap action bonnet and flue upper-temp-limit safty switches connected in series with the room thermostat.
Location: fisher,illinois,usa | Registered: June 03, 2003
Tim c cook-------- you have put a lot of effort into safety, I suspect you have some knowledge of burners or you have done a lot of homework to research your set up. Sounds good! Most people just try to get things working without thinking about mechanical failures that could lead to catastrophie. Nice job!
Originally posted by 51fitter: Tim c cook-------- you have put a lot of effort into safety, I suspect you have some knowledge of burners or you have done a lot of homework to research your set up. Sounds good! Most people just try to get things working without thinking about mechanical failures that could lead to catastrophie. Nice job!
Tim is one of the Veg oil heating guru's. Not sure if he came so starting by copying others who have made mistakes... or via making all his own mistakes. Either way he knows his shiat and his setups are good ones to emulate making you a guru too LOL.
BTW Tim... thank you for all your sharing. You make us all better and safer at our veg oil burn attempts.
_________________________ If you believe you can't YOUR RIGHT;
But equally so.... if you believe you can, YOUR RIGHT as well.
Location: North Tx | Registered: November 23, 2002