Syrup Block Arch

[zzammon]

This is my maple evaporator for the year. It is a test prototype. If it works as well as I hope, a permanent model with firebrick may be constructed next year. The only think missing is a door. I am thinking of a heavy piece of steel.

[Gissert]

Looks good! One suggestion is to get a cast iron log grate at Fleet so the fire is off the ground. It will draw a lot better that way, and make sure you get good air flowing in the front.

[zzammon]

Thanks Gissert, I have been thinking about that... I am away from a power source which makes a fan difficult. Maybe I will have to go with a battery.

[Gissert]

I think you will be fine without a blower. Add more stack to improve the draft. I run 9 feet on a 2 x 4 foot home built oil tank arch.

Leave an opening down low on front so the draft going up the pipe will suck in combustion air through the grates that the logs sit on.

[zzammon]

Good info Gissert. Please keep it comming. I suppose I could have an extra 4 foot piece of stove pipe on hand. I plan to give it a test run this weekend, if smoke comes out around the pan is that a sign that extra draft/pipe is needed? I can also forsee the front pan being much cooler than the rear pan with this set up. What do you think?

[Gissert]

For sure put extra length on you pipe. I am pretty sure you will need it.

You may get some smoke initially, but once you get a good fire going and your draft is good, you'll get almost no smoke, even out of the pipe. Split your wood so its about the size of your wrist, you generate a lot more heat that way. The downside is you'll be adding wood more frequently.

It looks like your blocks will tend to force the flames and exhaust gasses up to your back pan, and this is good. The fire under your front pan should get a good boil going too. You wont know until you try it though. Give it a test run with some water.

The metal you have lining the firebox may not last too long with the temps you will generate. Some of your block may crack from the heat too, especially if they were cast recently had have a lot of moisture in them yet. The heat generated can be amazing. I had a cast iron fire grate in mine last year and it was toast at the end of the season.

It looks like a pretty good setup, however, and inexpensive. This hobby can get out of hand real quick - almost like hunting or fishing.

Be careful and dont run your pans too shallow or you might get scorched spots. It takes a bit to "learn" how a pan behaves. If you run it a little deeper, you're evaporation will be cut down a bit, but you should not scorch. When you get close to being done, hold some sap in reserve so you can keep adding as the fire dies. You'll get a lot of evaporation after the fact and you might stil need to add some.

[zzammon]

I ran a water test run today. It worked better than I could have hoped for. I boiled down about 8 gallons of water in 1 1/2 hours. I didn't think that was too bad considering it took at least a half hour to get to a solid boil. I haven't been to town to get a stove pipe exension as you suggested Gissert. I did add a home made fire grate. About half way through i brought down a 2" computer fan conected to my 12V vexlar battery and pushed more air in. Boy did that make a difference, especially on the front pan. The extended stove pipe might have had the same effect. The photos are from before the fan. I think the fan doubled the heat/boil output. No cracked block either!

[Gissert]

Excellent! That's a very good evap rate for that size rig. Well done! Its amazing what a little forced air will do.

I hope to test my new blower set up tomorrow.