Side-Mounted Pre-Heater?

[StewieSugar]

My arch is a custom job with flat vertical walls. When I'm a foot away from the sides, the heat is high enough to burn my legs if I stand there too long. I am planning on adding interior arch board for insulation, but I suspect there will still be plenty of heat coming out the sides.

I was thinking about making some vertical-pans (more like square jugs) that mount to the sides of the arch. The pans would hold about 5 gallons, which is about how much I hope to evaporate every 30 minutes, and I'm hoping the heat will be enough to warm the sap enough in 30 minutes time.

Anyone do anything like this? Anything I should consider, or is this not a good idea?

Also, I checked on the cost of stainless steel to make these vertical pans, and it's too much for me to make custom pans. Anyone got ideas on what I can use on the sides instead of pans?

P.S. I've been following the various threads on stack-mounted pre-heaters, and I've got a few ideas for that as well, but I'm trying to find a way of using this wasted heat from the sides. Any ideas are appreciated.

[KenWP]

The heat coming out the sides should be going up ward towards the pan. If you insulate the sides properly You should almost be able to hold your hand to the side of the arch.

[RileySugarbush]

Pre heaters are great, but if you make a good one, the most you can improve your evaporation rate is about 15% and that would be if your sap was nearly freezing. If the sap is 50 degrees or so as it often is, the gains are significantly less.

Many of us would be way ahead if we put some of that effort and ingenuity into better combustion, finer split dry wood, blowers and insulation. The potential gains there are not nearly so limited.

For example, adding a blower and a firebox back wall to a half pint might improve the evaporation rate by 50% or more!

That tells you where the best bang for buck is.

[StewieSugar]

Sanity checks are helpful. Looks like I'll be focusing on insulating the arch as a first step.

Thanks

[Clan Delaney]

Buuuut.....

What if you built a set of pans that had, oh, 2" wide flues on either side of the pan, that were as deep as your flue space. They would essentially become the sides of your flue space. Then, all the heat that would have been going into the firebrick would be going directly into your sap!! And the sides of your flue wouldn't get any hotter than the sides of your pans. Am I mad, crazy, or genius?!?

Should I be running to the patent office?

It's been tried, hasn't it? Go ahead, tell me, I can take it.

[nas]

Buuuut.....

What if you built a set of pans that had, oh, 2" wide flues on either side of the pan, that were as deep as your flue space. They would essentially become the sides of your flue space. Then, all the heat that would have been going into the firebrick would be going directly into your sap!! And the sides of your flue wouldn't get any hotter than the sides of your pans. Am I mad, crazy, or genius?!?

Should I be running to the patent office?

It's been tried, hasn't it? Go ahead, tell me, I can take it.
yes to all of the above:o :lol:

[dano2840]

you shouldnt have hardly any heat coming fromt the side, unless you near the fire box, on my 3x8 you cant touch the side of the fire box but you can atleast hold your hand near the flue section of the arch, insulation is key, insulating as much as possable will probably increase evaporation almost as much as this pre heater idea, then add a preheater near the stack and theres 2x the evaporation

[Haynes Forest Products]

I have thought about the same Idea in my oil fired arch so when I built it I installed a SS flat plate heat exchanger that was 36x18. I put it at the end of the arch in the bottom by the stack. My thinking is you dont want to steal any heat from the pans. Worked like crap didnt add that much to the boiler set up maybe 30 degrees no great shakes.
I feel that the reason for having great insulation in the arch is 1st to keep from cooking the operator out of the room but also to reflect the heat back into the pan area and make radiant use of the heat. If all the side wals were coverd with heat robbing coils of cold sap you would not put the heat on the pans. Thats why what happens after the pans is a bonus but should not steal from them.

Clan I still think your a genius........ Question did you see spots when you went to bed after a long day of cooking

[Clan Delaney]

Okay, I'm not even kidding here. I am going to make a model of this idea out of whatever's in my recycling bin right now, and I'll be back with pictures. :cool:

[StewieSugar]

the reason for having great insulation in the arch ...


you shouldnt have hardly any heat coming fromt the side...


If you insulate the sides properly ...

As of today, my arch has a few firebricks I tossed in where they'd fit, and there is no insulation. My plan this summer is to add insulation and cut/trim the firebrick to fit tight. However, I'm not sure what type of insulation to use or how much to use.

So, what does "proper insulation" mean? Is there an R value I should be shooting for? Or, is there a standard thickness of certain material I should use?

[Clan Delaney]

I've moved my crazy idea over to a new thread (http://www.mapletrader.com/community/showthread.php?p=75102&posted=1) where I can give my ego the room it needs. :lol: