Pix of a furnace I want to convert

[Chaz]

Anyhow the small start of a square tunnel and the round hole could be beneficial in this respect, holding the heat in the spray of oil.

Thanx Deadeye. If it comes down to it, I can always fab something from stainless sheet or plate to rectify the problem......... I guess.
I appreciate the input!
  Chaz

[doug]

Dead Eye,
 Thanks for the description and diagram of a wet fire box and the fix. I've read about it but didn't understand.

[Chaz]

Hmmmm... I think I got it. Thanx Deadeye.
But I wonder if i should make a stainless tube about 3" long that the burner end can go into and then extend thru the round hole in the burn chamber? My concern has been that  the "corners" where the square meets the round. I think if the flame is narrow enough it will go thru the round hole without hitting those corners too much. But my guess is that if it does hit those corners it could "oil soak" them. But that's just speculation on my part.

But, what I think you are saying is that I can do an extension of the burner "after" the nozzle and into the burn chamber. Basically about 3" long. It would also have to be 4" diameter as that is the size of the round hole. So it would be a tight fit around the burner tube. Do you think that is ok?

Thanx again for all the insight!
  Chaz

[Dead Eye]

Look at how Dutch John at altfuel built his extension " Just add on to the box and a door to mount burner on,makes clean out a snap.

 I like this method.

[Chaz]

I went to his picture section but it doesn't show the inside, at least not what I need to see.

I'm wondering if I make the "tunnel"  a "trough" with the top open all the way thru from the front wall thru to the firebox if that would help. Or if I can just leave it a tunnel?

Come to think of it, I may just be wondering out loud.    I guess it's just time to fire it up and get dirty.    I just prefer to make at least MOST of my mistakes on paper, (or computer, as it were) . At least that's the way I do the other things I design.   

So........... what I am going to try is firing it the way it is and see if it works. Then start adding stainless. i.e. "U" shaped trough from as far back as the front wall to a lip that goes inside the fire box and maybe a target as I think I understand they can help. Then, if that has problems,  maybe take the top off the "tunnel" to make a trough which puts the top of the burner into the same "area" (I guess is the word) as the firebox.

Now, if any of that sounds futile or just won't work, PLEASE let me know. I will GREATLY appreciate the time savings. Not to mention the hassle and mess. 
Thanx
Chaz

[Dead Eye]

Well I am a bit confused by your drawing and the pix. The pix look to be a square (rectangle) firebox with the hut type refractory sitting there with its round hole.  The drawing shows the steel casing wrapped around the hut is this the case?
  Can you remove the hut and have a empty square steel box?
If so, extend the box line it with fire brick or plastic refractory and put a big door on it with a 4 1/4'" hole to mount the burner on.

 The big door is a pluss as clean out will need to be done every month or so.

This is why my build is all so very simple made from 10" pipe with flanges, to be easy to clean.

Cheers  D.E.

   

[Chaz]

Hey DE,
 Actually, the fire brick "box" (hut, I guess you are calling it?) is round and conforms to the round"steel casing" in which it is enclosed. (I'm sorry, I don't know all the proper terms and names.) The one photo "kind of" shows it back there, but not a great shot. The fire brick (hut??) is about 1" or so smaller than the steel ____ (tube/casing). It's a very nice looking "hut" with a tapered in lip at the top. I'd like to keep it/use it if possible, since it does just fit in there perfect. So yes, it is all "round".

So what I did was just form a fire brick "tube" back to the opening/access panel. It is square but the flame has to go thru the 4" round hole in the "hut" to get into the chamber. I can open the top of the "tunnel" up if that would be help in the burn. I was thinking the heat coming back around might be a good thing but, they did not have it that way. They had ceramic wool stuffed all around the burner tube, I suppose to protect it. That is why I made a "tunnel" instead of a "trough". I'm just a little concerned about having the burner nozzle 3" back from the actual inside of the "hut". And having to "shoot" thru the round hole in the hut. But that gives me the full 12" to the "target side" of the hut.

I have no problem making/adding a steel box extension, but I'm not sure it would help. (??) Can you help me with that? The access panel that has the burner hole in it, is pretty good size already. It's big enough that I could take the "hut" out, in the 2 pieces in which it was made, if I need to.

I hope that makes things a little easier to understand.
Thanx for putting up with my inexperience and all the help,
   Chaz