Ratio size of front pan vs. back pan?

[cjf12]

I know it's the "off" season and few are on here this time of year but was curious. I use my evaporator for sweet corn and I just cleaned it up and found a decent size hole in the flue. It's a 3x8 with the flue pan being 3x4. Is that the best arrangement? I'm considering new pans and thought maybe a smaller syrup pan may be better for evaporation. 2x3 to small? Go 3x3?

[Russell Lampron]

I believe most 3x8 evaporators have 3' front pans and 5' flue pans. That would be the configuration that I would want if I had a 3x8 evaporator. A bigger flue pan will give you a higher evaporation rate and there is a point where the syrup pan can be too small.

[Bucket Head]

A few years ago I saw a 2x6 with a 50-50 split on the pan size- 3ft syrup and 3ft flue. It was set up that way for boiling concentrate since the R.O. was now removing most of the water. I only mention this in case there are plans for an R.O. in the future. Just food for thought.

Steve

[Russell Lampron]

A few years ago I saw a 2x6 with a 50-50 split on the pan size- 3ft syrup and 3ft flue. It was set up that way for boiling concentrate since the R.O. was now removing most of the water. I only mention this in case there are plans for an R.O. in the future. Just food for thought.

Steve

The old Leader and King 2x6's were set up that way. The evaporation rate sucked because of the small flue pan.

My 2x6 has a 2' syrup pan and 4' raised flue, flue pan. I have been using an RO since 2005. I have an AOF/AUF arch and a bubbler too. I can control the color of my syrup by adjusting the concentration percentage. When I'm concentrating into the lower 20's I'm drawing off 12 gallons of syrup per hour.

I know of a 2x5 evaporator with a 4' flue pan and 1' syrup pan. That guy can only make dark syrup because of the configuration. The syrup pan is too small and the sugars caramelize too much in time it takes to go from flue pan density to syrup density. He tried a bubbler and it didn't help.

[DrTimPerkins]

Generally, as the concentration level goes up, the proportion of flat pan increases. For those boiling sap, a high amount of flue pan is needed (although as stated, you can have a syrup pan that is too small). For high concentrate, the flue pan size is decreased. At very high concentration levels (35 Brix +), there may be no flue pan at all, although manufacturers of high concentration RO and associated evaporators are backing off of that a bit and adding in more flue pan. More typical now for a moderate-high level of RO is a 50:50 (flue pan: syrup pan) evaporator, while sap and low RO evaporators may be 66:33 or 75:25 (flue pan: syrup pan). Our Lapierre HyperBrix RO (35 Brix) and Volcano 2000 evaporator is a 4' x 12' with a 33:66 (flue: syrup) ratio. I think our last evaporator (Leader) was a 3' x 10' with a 6' flue pan (60:40).

[Joel M]

Dr Tim.

What pan ratio would you recommend when boiling sap in the 15%-18% range?

Thanks!

[DrTimPerkins]

Dr Tim....What pan ratio would you recommend when boiling sap in the 15%-18% range?

Funny you should ask...I just did the final edits on Chapter 8 - Maple Syrup Production (authored by Abby van den Berg, Joël Boutin, Timothy Perkins) of the upcoming North American Maple Syrup Producers Manual 3rd Edition last week. The direct quote from that is:

"...the optimal flue pan percentage for sap between 16° and 20°Brix is generally considered to be about 60 percent of the total length..."

I'd check with the Lapierre folks to be sure (seeing as you have listed that you have a new Volcano 2000 coming next summer). They'll steer you right.

Full maple manual should be out in late-summer 2022. Stay tuned!

[Joel M]

Funny you should ask...I just did the final edits on Chapter 8 - Maple Syrup Production (authored by Abby van den Berg, Joël Boutin, Timothy Perkins) of the upcoming North American Maple Syrup Producers Manual 3rd Edition last week. The direct quote from that is:

"...the optimal flue pan percentage for sap between 16° and 20°Brix is generally considered to be about 60 percent of the total length..."

I'd check with the Lapierre folks to be sure (seeing as you have listed that you have a new Volcano 2000 coming next summer). They'll steer you right.

Full maple manual should be out in late-summer 2022. Stay tuned!

Thanks so much, I look forward to reading it!