Pan Sizes

[Mapleboy]

Hello once again,
We are laying out plans for our 2x8 evaporator but have a question about pan size.
I noticed some guys are going with a 2x5 flue pan and a 2x3 syrup pan instead of the traditional 2x6 flue pan and 2x2 syrup pan.
What are the reasons for this? Which do y'all think is the better system?
The arch will have a 3 ft fire box with AOF and AUF.
Pans will be raised flue.
Thanks!

[mudr]

From what I've heard and read, the shorter flue setup (5 ft instead of 6) allows for a better gradient to get established and has less of a niter build up problem in the syrup pan, especially ef you have an ro.

But don't trust me. I'm still on a steam pan setup. :)

[Bucket Head]

Go with the 5 and 3 set up. It will help with the gradiant.

And definitely go with the 5 and 3 set up if there is ever, even the slightest, long-shot chance in the future, of getting a reverse osmosis machine! You will be thankful when you start boiling concentrate, believe me. Others will say the same thing.

Steve

[mellondome]

Longer flue pan will evaporate faster.

Niter is caused by minerals in sap and their levels change from tree to tree and year to year.

Traditionally, longer flue pans have been used on raised flue sets to maximize evaporation rate. Where shorter flue pans were used on drop flues to prevent damage to the flues from throwing wood in the firebox.

So you should look at flue length in terms of raised or drop flue and evaporaton rate. On a 2x pan, you will evaporate about 8-10gph per foot of flue pan.

As far as gradient establishment, the longer the flat pan the faster it will form. Yes. This is due to the slow evaporation rate of the front pan causing the syrup to darken more. But if that is what you want, then just make the entire rig a flat pan with channels and dont use a flue pan. If you want to maximize evaporation for frame size, longer flue pan.

[n8hutch]

I have a 2.5x8 evaporator with a 5.5 foot flue pan, it has a nice gradient, I have had draw offs that last quite long sometimes I can maintain a draw and fire the evaporator at the same time.