converting 2 1/2 x 8 to oil

[davey]

I bought a 2 1/2 x 8 foot Wood fired Small Brothers Evaporator that I would like to convert to oil. Does anyone have any thoughts on what size burner I should use, BTU size, nozzle size, etc...?

[mapleguy]

The factory uses a Carlin Model 201crd burner for this size evaporator which uses 2.5 to 5.5 gallons of oil per hour. It doesn't have to be a Carlin, just one with the fuel supply range. the nozzle to use should be between 3.5 and 4 gallons per hour. Also the nozzle spray angle should be such that it spreads wide enough to get best cover of the interior of the arch. Fire should be adjusted so that flue temp is around 600 degrees F. If in doubt call Lapierre USA. in Vt.
Usually you can remove the wood doors and replace them with steel plate (about 3/8 inch) and bolt it in place. You need to remove the wood grates and seal the bottom where the ash pit was with galvanize metal. If you still have the bricks in, it's best to cover them with a layer of ceramic wool blanket of 4 or 6 pound density. This comes in roll form 1 inch thickness by 2 feet wide by 25 feet long. Any place there are no bricks should be covered with 2 layers placed at right angles to cover seams. If no bricks in arch then the whole interior should be covered with 2 layers.

[maplwrks]

davey,
My 2 1/2x8 came with a Beckett burner and 5.5 gph nozzle. This produced 1100 degrees at the stack. It also has a 60 degree spray. My experience is put a damper in the base stack and try a 4-4.5gph nozzle,which should get you under 900 degrees stack temp with a real hard boil.

[mapleguy]

The 5.5 nozzle seems way too big, especially if flue temp is that high. I use 600 F as a guide line - of course it's always a balance of best use of fuel and best boiling in the evaporator. When doing a conversion from wood to oil it's always best to look at an evaporator that is already been converted or one that has been built that way at the factory. Yes, the Beckett is a good choice as well. A few years back I did a conversion for a producer with a 2 1/2 by 10 and used a Beckett 800 unit.

[treefinder]

your nozzle size should only be about 4.0 60 -B a 4.0 nozzle at say 100psi will actually burn about 4.5 to 4.75. i know because i just went through this with mine and this is what leader told me . so you could be burning more than you think and could be just wasting it

[Fred Henderson]

1100 drgree stack temp is a waste of good fuel oil. I would be reworking that unit in a hurry. Is the "B" nozzle solid or hollow, I have forgot?

[treefinder]

i think "B" is a hallow but i'm not sure . or it is the pattern of spray. your fuel gun should be at least 9 inches from the outside wall of your evap if not it could make carbon balls that will get the size of bowling balls if you don't catch it in time and should be 12" off the floorand that from the bottom of your pan..

[maplwrks]

Fred,
1100 degrees was a little hot, but , man how that rig would boil!!
We did cut it back to 3.5gph nozzle, got 685 degrees at the stack. The result was I lost my boil in the back 1/3 of the flue pan. My next plan is to put a damper in the base stack to improve the boil. If this doesn't improve the boil I will try a little larger nozzle.
One interesting fact I realized while playing with this for 2 years was that gal. per oil to gal. per syrup ratio did not change over the 2 year period. I had run the 5.5 nozzle for 1 year and the 3.5 nozzle for the next year. It stayed a constant 4/10ths gal. oil to a gal of syrup. I'm really hoping that the damper will improve the boil with the 3.5 nozzle. I like saving fuel whenever I can.

[Fred Henderson]

Saving fuel is the name of the game. Keep the BTU's where they are needed and will do the most good. A damper might be the answer. The home made(I built) wood fired unit that I just sold had a damper in it. I made 60 gals last year and used 6 face cords(18") wood.

[NH Maplemaker]

Maplwrks, My Dallalre 3x10 has a damper in the base and if I forget to shut it you realy see a differance in the boil :!: As soon as it is shut, back pan goes to full boil :!: Jim L.

[maplwrks]

THAT'S WHAT I'M TALKING ABOUT!!!

[murferd]

Has anybody got a picture of the dampner,or could somebody explain it thoroughly for a small minded person.

[maplwrks]

It works just like a damper in your stovepipe. You close it down to keep the heat in the evaporator, increasing the boil in the pan.

[davey]

Where, in relation to the damper, do you read your stack temp above or below and how far either way?

[gearpump]

Does a barometric damper work as or better then just a damper in the stack? I have a barometric one on my 2x6, but I have thought about adding a regular stove pipe damper before it to help with keeping the heat under the pans. The stack temp normally runs about 650' to 700' with a 3gph nozzle.