Leader Evaporator

[Woody]

A friend is borrowing an older leader 2x8 evaporator that has the finish pan in the middle of the two flue pans. We can't figure out why it was built that way since the only thing we've ever seen is where the finish pan is directly above the fire box and in front of the flue pan. On this unit the finish pan is in the middle of the arch. What's this arrangement called and what's the idea behind it?

Is there a special way to configure the fire brick in the fire box?

Should he line the flue with a ceramic blanket?

Also, we're wondering if heat is fairly evenly distributed along the entire lenght of an arch from the fire box to the stack. (back to trying to figure out why the finish pan is in the middle)

thanks

[jdj]

If I remember correctly this evaporator you are explaining has a shallow flue pan in the front, above the firebox, the the flat syrup fan in the middle, then the deep flue pan in the back.......correct?

I found this description online:
VERMONT
3-PAN EVAPORATOR

More than 80% of the entire heating surface of the Vermont Evaporator is fabricated into corrugations or flues.

The three-pan evaporator is made up of the heater or flue pan, the syrup pan and the corrugated front pan. These pans are connected with a free flow- ing - no drip simple hose connection protected by stainless steel clamps.

The corrugated front pan is fabricated into two and a half inch deep cor- rugations, which gives more heating surface.

[Woody]

Yup, that's the one.

[Flat47]

That design was a holdover from the Vermont Evaporator Company. Leader bought them somewhere in the '50s I think (I'd have to go dig through some old books). The 3 pan system was very popular in some regions for a while, and can still be ordered new from Leader. Their catalogs showed the Vermont 3 pan up until fairly recently. I always thought it was a neat design, but never boiled with one so I can't say how well they run.

[3rdgen.maple]

That is the same rig my grandfather boiled on but it was a 3x8. It was really efficient as far as I can remember. However he could not stand the syrup pan in the middle and thought it was a bad design. I remember him saying the sales pitch that got him to buy it was way oversold. He ended up rerouting the piping and Had a finishing pan made and extended the arch and put that on the front. He did not have it piped and just added sweet into it till he got the level where he wanted it. I still have that finishing pan. I remember him saying after he made the improvement that it was now a real evaporator. A couple years later he ditched the coragated pan and put another drop flue in its place when the sales man sold him the new pan he put a peice of bailing twine on the stack and told him if he could burn it off he could keep the pan and they would refund him his money. That string rotted off before it burnt off after several years. Seems odd now days how everyone talks about stack temps but after he added that flue pan he no longer had to boil all through the night to keep up. Said it was the best thing he ever did to improve his gph. Dont ask me what he did with the piping to change it I was just a teenager way back then.