Oil fired arch design

[Cider Hill Maple Farm]

The time has come to build a new arch for my rig. The current one was a wood fired converted to oil, and is well on its way to the rust heap! Now I'm finding out that a wood and oil arch are constructed in different ways. We have a 3' x 12' raised flue unit including, a 3' x 8' flue pan and two 2' x 3' cross flow syrup pans. I want to construct the new arch to be the more efficient than the old, so a few questions need to be asked. When designing the combustion chamber, how far beyond the syrup pans until the ramp starts, or does it ramp? Second, how far back on the flue pan until it flattens out? I've done a little research but I'm coming up with little answers. What design difference between wood and oil makes the critical difference? Wood is path and draft, where oil is radiant. Any comments would be appreciated. After I collect design ideas, I will then draw it up on CAD and share with all. Thanks in advance.

[backyard sugaring]

I built an oil fired evaporator. This year I moved my oil gun a little bit lower and lowered the ramp. I started my ramp right where the flue pan starts. We closed the opening to where the flue gases exit into the flue. The opening is the same size as the 6" flue pipe in square inches. You are right about the radient heat. If you picture where the flame cast a light on the pan is where it is the hottest. The firebox should be the 1 square foot to each gallon per hour tip used in the gun. I hope this helps of course my evaporator is much smaller than you are planning on building. Good Luck Lee

[325abn]

Google "oil fired maple" and you will find quit a number of papers on this issue. Some old some new. Some great info on the configuation of the fire box.

[Cider Hill Maple Farm]

Thanks backyard and 325, I will look into all info. Like I said in my post, I'm going to collect info and then draw it up on my CAD for all to comment and review.Thanks to all!