Low boil temp? 200 F

[Rick_Seebeck]

I fired my homemade barrel arch evaporator today and tested it with water in the pans. I could only get water temps to 200 degrees F. The arch is made of a barrel stove that is 1/4 thick rolled steel. I fire bricked two bricks up the side but not all the way to where the two pans are. I bricked up the back just past the last pan opening so that the flue gasses must run across the bottom of the rear pan. 8 feet of 6 inch stack with a butterfly damper.

The two pans are 20X12X6 steam table pans. There are two holes cut in the top of the arch that allow the heat to hit the bottom of the pans. The pans do not sit down inside the barrel. I did install a gasket around the opening so the pans sit pretty tight. When things are really rolling the sides of the pans are not all that hot.

I have tried more draft, less draft and found that wide open draft works best.
The outside temp today was 23 F with a light breeze.

I have thought about cutting the holes bigger and setting the pans down in the arch about 3 inches. Any help?

Here are some pictures.
http://s266.photobucket.com/albums/ii243/Rickster_42/

[halfast tapper]

The only thing the pans should set on is an edge around the outside of the arch. Your pans should have the full flame and heat on the whole surface of the undereside of the pan.

[325abn]

I think your idea of cutting the holes bigger is right on target!

[maple flats]

Was the water boiling? If yes, verify the thermometer. But then, my evap has 2 themometers, one on each draw off side and when first starting with unsweetened pans the rig starts boiling well below 212, regardless of which thermometer I read. I can't give an exact # because mine are the type that only give 0 and 7 with lines for each degree between and a few lines below 0 and above 7. On these the 0 is calibrated to be and is adjustable to reflect the boiling point of water on that particular day and the 7 is then 7 above the boiling point.
One other point, how far from the fire to the bottom of the pans? This could be part of it if too far. I think you would have more problems if you cut the holes bigger because the flames would then burn the pans at and just above the sap level. This burn would possibly keep you from making the best tasting syrup.

[Uncle Tucker]

Rick your evaporator looks real nice.
The question I have is was the water boiling hard?
The problem with dropping the pans lower is burned sap on the sides. If you are getting a good boil than I would keep it the way it is.

[Rick_Seebeck]

The pan are 26 inches from the fire grate. Too far? I just tried moving the fire brick closer to the fuel door creating a smaller fire box but forcing flue gasses closer to the back pan. The temp only got to 175 on the back pan but got to 200 on the front. I think I will move it back. The water boils slightly. Small bubbles but not a rolling boil.

[Russell Lampron]

From what I can see in your pics you need a larger draft opening. You need to get a lot of air into the fire to get it to burn hot. You should also brick the sides all the way to the top. The bricks keep the heat inside the firebox. You don't need the damper, run it wide open. If that still isn't enough heat try going up to an 8" pipe.

Russ

[TapME]

When I had my barrel stove there was only 14'' from the grate to the bottom of the pan and that gave me a rolling boil most of the time. In you pics if you raise the grate you may have a tough time feeding the wood to the stove. Try raising the grate temporarily if you can and see if flames closer to the pans make a difference. My stack was 6'' and it worked fine.

[maple flats]

Raise the grate, make sure you have lots of air. How high is your stack, at least 2x length but more helps. your rig might be too short for that formula, try adding more stack.

[RileySugarbush]

I recommend dropping them down in. That will reduce the distance to the fire even better than raising the fire grate. Also increase the area exposed to the heat and reduce the area exposed to the cold. Keep the pans pretty full, as deep as you can without losing sap. I did it that way for years and after filtering you won't notice the burned edges. I honestly think the syrup I made that way was better tasting than what I can make on the "real" evaporator.

[RileySugarbush]

I recommend dropping them down in. That will reduce the distance to the fire even better than raising the fire grate. Also increase the area exposed to the heat and reduce the area exposed to the cold. Keep the pans pretty full, as deep as you can without losing sap. I did it that way for years and after filtering you won't notice the burned edges. I honestly think the syrup I made that way was better tasting than what I can make on the "real" evaporator.

Check out some old photos:

http://web.mac.com/jabushey/iWeb/Riley%20Retreat/Maple%20Sugaring.html

[TapME]

John, how did you make the arch front? I know it is off topic a little.

[Rick_Seebeck]

I forgot to mention that I installed a 1/2 inch gasket around the opening. The pans sit on the gasket. I have been boiling with only 1 inch of water in the pan and the pans do not get very hot. Should I put more water in them? I wonder if the heat is being pulled off by the metal pan, like fins of a radiaor? The sheet metal next to the pan is so hot that water sizzles and beads off screaming! I think my pipe is high enough becaus it draws air like wild. Sounds like a jet taking off and the pipe gets so hot it glows for the first 3 feet.

I think my next step is to drop the pans 3 inches into the fire box. Thoughts?

[RileySugarbush]

Rick

You know my opinion....drop'em all the way in and let it rip! I don't think you will regret it.


TapME,

That front was a sheet of 1/8 inch steel, with a bent lip on the top to hang on the blocks, and then anchor screwed to the front of the blocks. Behind the sheet are welded a few stiffeners, meant to keep the sheet flat. The opening for the firing door was flame cut and hinges/latch were just welded on.

The stiffeners were a bad idea, since they got hotter than the plate and caused all sorts of distortion due to differential expansion. I ended up filling the resulting gaps with fiberglass cord and gasket cement to seal it up.

It was making this thing that convinced me to build my own arch for my current rig.

[TapME]

Thanks John with the info.
We're both on the right track, the flame is not close enough to the pans.

[yooper]

Rick, looking at your pictures I would also agree the pans are to far from the fire. The stack looks lower than your pans, which is probably drawing your heat away before heating the pans. If you crack the door and look at the flames, I bet the flames are being drawn horizontally right to the stack and not touching the pans.

If you could lower the top so it's flush or just below the top of the barrel I think it would help a lot.

Nice looking job though.

[Rick_Seebeck]

I took your advice and dropped the pans into the stove, applied fire brick all the way up the sides and back. Fired it up today and could only get 175 degrees! Man was I *$@#$&. My dad walked over, took one look at the fire and said, "Son, that fire is burning wet wood, it'll never boil water." I thought, ya right- fire is fire. Went to my dad's shop grabbed some very dry oak, threw it in the fire box and within 3 minutes I was boiling at over 219 degrees. Man, I hate it when he is still right after all these years!

Moral of the story, if you are lucky enough to still have your dad around at my age, ask him for advice. 70+ years on the planet yeilds a lot of experience.

[Justin Turco]

Hey Rick, I had a barrel stove at one point (like everybody). I think you need to raise the grate so that you have a 14-16 space between the bottom of the pan and the grate. Somewhere below the grate I would have a "good" opening for draft. Maybe directly UNDER the grate. (I used to get a huge pile of unburned coals in mine because I had no grate and the air just fed through the front of the stove. The air needs to pass through the coals!) I would definately brick all the way to the bottom of the panon the sides and slope up or just "step up" the back of the fire box with brick just like the big evaporators do to hold the heat on the bottom of the back pan. I would leave the damper in the pipe. If you end up with flames shooting out the stack like mine used to do you can close it down and keep the heat in the firebox. Otherwise let her run wide open. I am of the opinion that having fire touch the sides of the pans is not a good thing. You want heat on the bottom only.

P.S. Good Moral to your story.

[OGDENS SUGAR BUSH]

the older you get the smarter he gets

RICH

[lpakiz]

Ain't it tho??
When I was 15, my dad was so dumb I was ashamed of him. Now I'm 50 and amazed at how much he learned!!

[RileySugarbush]

Congratulations Rick! Now how about a little experiment:

One batch with the pans set down in and the next with them raised and bottom heat only.

Glad you have it boiling!

[TapME]

I know that I have done some things that I'm not to proud of so don't feel bad. Just remember that we are the next generation.

[Pete S]

We have a metal box that would be a very similar set-up. I wasn't able to see within the box but here's what we did.

The interior of our evaporator was WIDE OPEN, and things boiled OK, but I thought that possibly a LOT of the heat was running "under" the pan and not "against" it.

SO, I made a "dam" for the flue gasses. I took a sheet of metal, and blocked off the back of the fire box almost all the way to the top. NOW, the flames and the heat has to go "over" this dam and then down a bit to enter the flue stack.

Try it and you should see notable results right away,.........we did!

HTH Pete