wood gassifier for making maple syrup

Most wood fired units to boil down maple sap to maple syrup are low tech and appear very inefficient. Basically, there is a pile of wood under the pan, and that's your heat source. I can't image they get more than 30-40% efficiency.

Is there a way to rig up a wood gassifier to boil maple sap? I am thinking running a hydronic system with oil instead of water. Run at ~275F. Pipe the hot oil through copper tubing coiled in pots to boil the syrup.

Has anyone ever considered this?

Andrew

There are woodchip-fired gasifiers for maple sugaring.

I'd say it would be more to the point to find out for sure whether the wood fired units you've seen are indeed inefficient, and if they are, attack the problem head-on and improve the combustion efficiency and the heat transfer efficiency.

The ones I've seen in the northeast would be pretty hard to improve on with all the preheat, economizer circuits, primary and secondary combustion control, insulated fireboxes, and very specialized systems for routing and controlling flue gas flows and temperatures.

I am here in Indiana; not a lot of sugarbush operations around here. Do you know the brand of evaporator you saw in action that had good air control? It sounds like they have their act together.

Andrew

For efficient low tech check out rocket stoves (particularly rocket mass heater style).