New arch

[tpathoulas]

We are planning to make a new arch and stack this summer. Can someone please point me in the right direction for plans, best ideas, and steel to use?
Thanks in advance

[maple flats]

What size are you thinking?

[tpathoulas]

What size are you thinking?
Great question, I totally forgot to mention size. I have a 4x4x12 inch deep flat pan. It was not made for making syrup but it has served us well and we plan to keep using it. It holds 100 gallons when full but we usually cook at about half full. Even with the poor homemade arch we have been using, we can boil off 10-15 gallons per hour. Our problem is our stack is shot and our arch is far from air tight. Currently our stack leaves the shack straight out and then up about 14 feet. We plan to change the stack so it goes straight up and out the roof to maybe 16 feet. We are also thinking of adding a blower to the stack. We are also hoping to add a hood with a stack that will exit straight up and be about 3 feet from the smoke stack and about 2 feet lower in height. My brother in law welds and loves to fabricate but we want to do it the best we can.
Thanks for asking!

[motowbrowne]

Rule of thumb for flat pans is 1gph per square foot, so you should be able to do 16 on that size pan without too much optimization. Personally, I'd think you'll gain a lot of efficiency (for flat pans) by adding some length to your setup. For example a 2x8 would be the same size as your 4x4 and would probably evaporate a similar amount, but you'd be using more of the heat before it went out the stack. As such it would be more efficient. With that in mind, could you find another 4x4 pan? Make yourself a 4x8 and be in the 32gph range. Depending on how flat the bottoms are and how level everything is, you should be able to run them with only a few inches of sap in the pan and get a decent boil going.

[tpathoulas]

I had been giving some thought to adding a 2x4 flat pan to use as a finishing pan. I thought of using the big pan to boil but have the sap drip into the smaller pan to maintain boiling. I try to batch cook about 150-250 gallons with each cook. Do you think this would help? I'm a little worried about how high my big pan would be to drain into the smaller pan.

[motowbrowne]

With a 4' wide arch, I think you could probably keep adding pans until you hit 12' long and it'd just keep getting better. That might be bigger than you want to go, but any additional length will be a step in the right direction.

[tpathoulas]

Another question. How big of stack should I make? 8-12 inch diameter? I plan in it being 12-16 feet tall.