Oil furnace build

[DaveH]

Nice build Pete  

(bit of a 'bummer' all that rain)
 
DaveH

[Pete O]

Gave the thing a bit of a firing today, more for the heck of it than anything although Colin's book advises a low-temp firing to dry it out, given that it has been a month since casting the refractory I'm not sure this was necessary but here it is:
set up
   
some of our precious home heating fuel (firewood) being wasted
   
and I actually got some oil burning later on
   

It was very evident that I need adjustable feeds for both the air and the oil, the throttle on the leaf blower was not sensitive enough and dribblig oil into a funnel from a jug is just not going to cut it. So, still a little work to do before anything is melted.

I think I would like to set up a gas burner as a starting fuel, burning wood results in embers being blown everywhere out of the exhaust, would not be a good thing here in summer. Will have to look into how to set up a gas burner.

[dallen]

drill and thread a hole in the side of the pipe and hook up a gas bottle with an adjustable regulator on it,

remember that the blower is always turned on first, before turning on the gas bottle.

you may also need to do like some do and put a dump valve between the blower and the furnace to control air, or make some type of damper, something as simple as a piece of card stock over the inlet will control air flow.

[Mayhem]

Looking good Pete

[Pete O]

(07-14-2015, 07:32 AM)dallen Wrote: drill and thread a hole in the side of the pipe and hook up a gas bottle with an adjustable regulator on it,

remember that the blower is always turned on first, before turning on the gas bottle.

you may also need to do like some do and put a dump valve between the blower and the furnace to control air, or make some type of damper, something as simple as a piece of card stock over the inlet will control air flow.

So does that mean that with the blower on, it is no more complicated than just getting some gas into the pipe? No jets etc to worry about? I've had a look at some gas burner setups online but they are all on systems that are set up to use gas as the main fuel, so a bit more involved in the gas burner. I was thinking of a tube that could be inserted into the side of the air pipe with a hole directed downstream and a small ball valve, such that the whole thing could be shut off and withdrawn once the oil is burning. I think I have a piezo igniter in a drawer somewhere too, could be fixed in the pipe downstream from the gas inlet.
Something that is not clear to me with this system is whether the gas should burn inside the pipe or only where it exits the air pipe inside the furnace.

[dallen]

(07-14-2015, 06:43 PM)Pete O Wrote:

(07-14-2015, 07:32 AM)dallen Wrote: drill and thread a hole in the side of the pipe and hook up a gas bottle with an adjustable regulator on it,

remember that the blower is always turned on first, before turning on the gas bottle.

you may also need to do like some do and put a dump valve between the blower and the furnace to control air, or make some type of damper, something as simple as a piece of card stock over the inlet will control air flow.

So does that mean that with the blower on, it is no more complicated than just getting some gas into the pipe? No jets etc to worry about? I've had a look at some gas burner setups online but they are all on systems that are set up to use gas as the main fuel, so a bit more involved in the gas burner. I was thinking of a tube that could be inserted into the side of the air pipe with a hole directed downstream and a small ball valve, such that the whole thing could be shut off and withdrawn once the oil is burning. I think I have a piezo igniter in a drawer somewhere too, could be fixed in the pipe downstream from the gas inlet.
Something that is not clear to me with this system is whether the gas should burn inside the pipe or only where it exits the air pipe inside the furnace.

with a burner with a blower on it you don't need an orfice as the blower is providing the air, on a Burner that sucks in the combustion air by the gas exiting an orfice which causes the air to get sucked in to the vacumn that's created.

To make it pretty simple no you don't need and orfice in your burner if you are going to use a blower.

I worked on burners that were as big as 750 million BTU's and the gas was just a free flow into the burner body.

My burner which has been copied and modified by a lot of people on the net just dumps the gas into the air stream where its mixed. you want I can find some photos

I have a little project I'm going to be pouring in a day of two I'll video it and post the link so you can see how I run mine.

[Pete O]

I'll look forward the the video Dallen. You've explained it pretty well so thanks for that, thought it should be fairly simple when no venturi effect is required. I probably have enough junk in boxes and drawers to set this up.

[dallen]

got to digging around on PB and found this photo of the inner workings of my burner, as you can see the short line with the silver colored quick connect is the propane line into the burner, I made it that length because I wanted the gas to be in the flow line of the air from the blower which on my burner comes in from the side.

[Good Mann]

This could be a case of closing the barn door....
However, just stumbled upon your post.
Furnace looks terrific.  When are you putting into production?!
The site following, could be of assistance regarding refractory material, furnaces.
i have submitted questions and always had informative, speedy responses.

arnoldhoward@att.net
Hope this helps.

GM.
NOT General Manager!

[Pete O]

Thanks GM, not sure when i will be starting to cast anything, going by current progress it will not be soon!

Dallen, thanks for posting the photo, the propane line is simple enough so I'm sure I can make that happen. Could you explain the function of the other two feed lines on your burner? Looks like you are perhaps using compressed air and a venturi to feed liquid fuel, but that puzzles me as you mention a blower also.
I've been to a couple of clearing sales this week, spotted a propane regulator at one of them that would have been perfect for the furnace but it had been bundled in with a heap of oxy-acetylene gear that got dealer bids so I missed out.