Remade evaporator.

[wlatrout]

One other question I was thinking today is would it be better for the boil process to reverse the pans,with the short pan in front?

[Keitha333]

Looks like it things should be fine with your design, I would focus on your airflow. It either isn't getting enough and can't get hot enough or your fan is blowing too much and blowing the heat out the stack.

[wlatrout]

Thanks for the reply.

[maple flats]

I wonder if the slope you have under the rear pan should be all of the way to under the stack base? On every evaporator I've had (3 over the years) that space pushing the heat up ended a few inches (3-5") before the stack base. All of my evaporators had a very hard boil, with or even without a blower. I suggest you try removing that ramp at about 3" before the base stack begins, at that point have it drop down about 6 or even 8". Be sure to have brick under that lower area too, to protect the arch floor.
How are you reading the stack temperature, with a probe in the lower end of the 6" stack or just using a surface mount, or a IR non contact on the base stack?
I suspect in your attempt to push the exhaust out you are squeezing or restricting it right under the base stack.

[wlatrout]

Dave, The restricted area goes to the stack base. I will go back in and drop it down and see how it reacts. I am using a non contact temp. reader.

[wlatrout]

Today I made my first sap boil Overall it worked great It boiled much faster then it did before the conversion . Had a rolling boil in the 2 runs on the left side of the front pan , but the right or finishing run boiled but not as vigorous as the other 2. The back pan with a divider running crosswise yust boiled but not hardy. Over all I am pleased. Just need some input on why the rt. front is not as vigorous. Try to keep the wood even across the fire box.

[Cjadamec]

Your draft blower is mounted in the front and pushing the fire towards the back of the evaporator. That's likely why you have a slightly colder spot in the front. You could try looking into how your draft enters the fire box and possibly make a baffle to force the air under the grate and under the fire rather than rise up in front of the fire creating a cold zone by the front wall of the fire box.

[wlatrout]

Thanks I'll try that.