Photo of retrofit air-over system

[sasanford]

I'm working on an on-line energy assessment / educational tool for maple syrup production for a USDA site. I'm looking for some photos of wood fired arches that have been retrofitted with a forced air system and / or combustion air pre-heater. The photos will be used on an educational web site to illustrate what the systems look like and how they work.

I could also use photos of sap pre-heater, RO system, SteamAway, sugar house with steam venting (of-course) and a few sugar bush picture with tapped trees.

If you have some photos you'd be willing to share, I would appreciate it.

Thanks for your help.

Scott Sanford
University of Wisconsin
Rural Energy Program

60 taps in buckets
2 x 4 flat pan on homemade arch

[smitty76]

I have been experimenting with the heated combustion air but do not have any pics. however, I can have some in a few days along with some preheater pics and such.

[Breezy Lane Sugarworks]

interesting....it sounds like you are saying that pre-heated combustion air is more efficient. I may be wrong, but I always thought that cold cumbustion air is more efficient because colder air has more oxygen in it to burn better. at least on a wood fire anyway...I do know that warmer fuel in a oil burner is better because it will atomize more evenly. just a thought.

[smitty76]

what makes it more better is not that it makes the wood burn better but rather it does not lower the fire box temp. just like putting cold sap in a boilling pan will slow or stop the boil, cold air in the firebox will create a cooler fire because some of the btu's create by combustion are consumed by the cold air. The hotter the air blown into the firebox, the more amount of btu's are getting into the pans.

[Flat47]

what makes it more better is not that it makes the wood burn better but rather it does not lower the fire box temp. just like putting cold sap in a boilling pan will slow or stop the boil, cold air in the firebox will create a cooler fire because some of the btu's create by combustion are consumed by the cold air. The hotter the air blown into the firebox, the more amount of btu's are getting into the pans.

Very well said.

To put it another way: beyond the basic fire triangle of heat, fuel, and oxygen is the chemical reaction occurring in wood combustion through the gasification of the wood. In short, more heat = more combustion.

[sasanford]

Here is a link to a paper entitled "Guidelines for Improvement of combustion efficiency for maple producers". The paper was commissioned by U of VT Extension. It has information on the air-over draft system and combustion air preheating.

http://www.uvm.edu/~pmrc/Combustion.pdf

Hope it's helpful.

Scott